Sample records for resin-treated polyester fabric

  1. Microwave heat dyeing of polyester fabric

    Microsoft Academic Search

    Sam Soo Kim; Su Gyung Leem; Han Do Ghim; Joon Ho Kim; Won Seok Lyoo

    2003-01-01

    The effect of padding solution on the microwave heat dyeing of polyester fabric was studied extensively. Polyester fabrics\\u000a were impregnated in aqueous urea solution and aqueous sodium chloride solution for 10 min and then dyed for 7 min by microwave\\u000a apparatus (2 450 MHz, 700 W) under optimum conditions which provide good exhaustion. Aqueous solutions of urea and sodium\\u000a chloride

  2. The Advantages of Polyester for Use in Coated Fabrics

    Microsoft Academic Search

    P. W. Mayer

    1973-01-01

    Polyester fabrics, with many superior physical properties, increasingly competitive economics and adaptability to the coated fabric environment, are gaming rapid acceptance in coated fabric applications. Higher modulus fibers with greater resistance to thermal shrinkage provide coated fabrics with superior dimensional stability and lower creep proper ties. The attributes, coupled with polyester's resistance to acids and climatic (humidity) changes contribute to

  3. Effect of Abrasion on Protective Properties of Polyester and Cotton\\/Polyester Blend Fabrics

    Microsoft Academic Search

    A. Shaw; Y. J. Lin; E. Pfeil

    1996-01-01

    ®finish (fluoroalkyl methacrylate polymer) drastically reduced the sorption and penetration of pesticide through cotton, polyester, and cotton polyester blend fabrics (Shaw, 1992). As surface properties change due to abrasion, the level of protection provided by “worn” fabrics against pesticides may change. This study was conducted to determine the effect of surface abrasion on the sorption and penetration of pesticide through

  4. Cationization and gamma irradiation effects on the dyeability of polyester fabric towards disperse dyes

    Microsoft Academic Search

    Maged H. Zohdy

    2005-01-01

    The effect of hydrazine hydrate (HZH) treatment and\\/or gamma irradiation on the dyeing, mechanical and thermal properties of polyester fabrics (PET) was studied. The different factors that may affect the dyeing performance, such as concentrations of HZH, benzyl alcohol and pH values, were investigated. In this regard, the colour strength of untreated polyester fabrics dyed with the dyestuffs Dispersol blue

  5. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    NASA Astrophysics Data System (ADS)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting; Sun, Kaikai; Hu, Xili; Wang, Yujiao; Xu, Xiaoqi

    2014-10-01

    Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  6. The antifungal activity of corona treated polyamide and polyester fabrics loaded with silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Saponjic, Z.; Ilic, V.; Vodnik, V.; Mihailovic, D.; Jovancic, P.; Nedeljkovic, J.; Radetic, M.

    2008-07-01

    This study is aimed to highlight the possibility of using the corona treatment for fiber surface activation that can facilitate the loading of silver nanoparticles from colloids onto the polyester and polyamide fabrics and thus enhance their antifungal activity against Candida albicans. Additionally, the laundering durability of achieved effects was studied. Corona activated polyamide and polyester fabrics loaded with silver nanoparticles showed better antifungal properties compared to untreated fabrics. The positive effect of corona treatment became even more prominent after 5 washing cycles, especially for polyester fabrics.

  7. Static properties and moisture content properties of polyester fabrics modified by plasma treatment and chemical finishing

    NASA Astrophysics Data System (ADS)

    Kan, C. W.; Yuen, C. W. M.

    2008-01-01

    Low temperature plasma treatment has been conducted in textile industry and has some success in the dyeing and finishing processes. In this paper, an attempt was made to apply low temperature plasma treatment to improve the anti-static property of polyester fabric. The polyester fabrics were treated under different conditions using low temperature plasma. An Orthogonal Array Testing Strategy was employed to determine the optimum treatment condition. After low temperature plasma treatment, the polyester fabrics were evaluated with different characterisation methods. Under the observation of scanning electron microscope, the surface structure of low temperature plasma-treated polyester fabric was seriously altered. This provided more capacity for polyester to capture moisture and hence increase the dissipation of static charges. The relationship between moisture content and half-life decay time for static charges was studied and the results showed that the increment of moisture content would result in shortening the time for the dissipation of static charges. Moreover, there was a great improvement in the anti-static property of the low temperature plasma-treated polyester fabric after comparing with that of the polyester fabric treated with commercial anti-static finishing agent.

  8. Optical properties of three-dimensional P(St-MAA) photonic crystals on polyester fabrics

    NASA Astrophysics Data System (ADS)

    Liu, Guojin; Zhou, Lan; Wu, Yujiang; Wang, Cuicui; Fan, Qinguo; Shao, Jianzhong

    2015-04-01

    The three-dimensional (3D) photonic crystals with face-centered cubic (fcc) structure was fabricated on polyester fabrics, a kind of soft textile materials quite different from the conventional solid substrates, by gravitational sedimentation self-assembly of monodisperse P(St-MAA) colloidal microspheres. The optical properties of structural colors on polyester fabrics were investigated and the position of photonic band gap was characterized. The results showed that the color-tuning ways of the structural colors from photonic crystals were in accordance with Bragg's law and could be modulated by the size of P(St-MAA) colloidal microspheres and the viewing angles. The L?a?b? values of the structural colors generated from the assembled polyester fabrics were in agreement with their reflectance spectra. The photonic band gap position of photonic crystals on polyester fabrics could be consistently confirmed by reflectance and transmittance spectra.

  9. Comparison between thermal insulation and thermal properties of classical and microfibres polyester fabrics

    Microsoft Academic Search

    L. Schacher; D. C. Adolphe; J.-Y. Drean

    2000-01-01

    A lot of fibre and fabric structures or finishing parameters influence the functional properties of fabrics. In order to assess the thermal properties of conventional polyester and microfibre types of fabrics the plate\\/fabric\\/plate method for conductivity or cool\\/warm feeling was used. Fabrics made of microfibres show lower heat conductance and therefore higher thermal insulation properties. Microfibre fibres exhibit a warmer

  10. Studies on Polyester\\/Waste Silk Core-spun Yarns and Fabrics

    Microsoft Academic Search

    C. Rameshkumar; R. S. Rengasamy; N. Anbumani

    2009-01-01

    In this study, 100% polyester and silk yarns and core-spun polyester silk yarns with two core\\/sheath ratios are produced. Fabrics are knitted from these yarns. Effect of core positioning on sheath coverage and core-sheath ratios and plying on various properties of yarns is analyzed. High level of unevenness is observed for core-spun yarns and plying improves many of the yarn

  11. Surface modification of polyester nonwoven fabrics by Al 2 O 3 sol–gel coating

    Microsoft Academic Search

    Xueliang Xiao; Fang Chen; Qufu Wei; Ning Wu

    2009-01-01

    Nonwoven polyester (PET) fabrics have been extensively studied for various applications. However, the nonwoven PET fabrics\\u000a have poor wettability. In this work, nonwoven PET fabrics were impregnated in a stable and transparent alumina sol that was\\u000a prepared by the hydrolysis of aluminium isopropoxide using the sol–gel technique. The Al2O3 particles were coated on nonwoven PET fabrics after the rolling-drying process.

  12. Sonochemical coating of cotton and polyester fabrics with "antibacterial" BSA and casein spheres.

    PubMed

    Shimanovich, Ulyana; Cavaco-Paulo, Artur; Nitzan, Yeshayahu; Gedanken, Aharon

    2012-01-01

    A novel antibacterial coating for cotton and polyester fabrics has been developed by using drug-loaded proteinaceous microspheres made of bovine serum albumin and casein proteins. The microbubbles were created and anchored onto the fabrics (see figure) in a one-step reaction that lasts 3 min. The sonochemically produced "antibacterial fabrics" have been characterized. The efficiency of the sonochemical process in converting the native proteins into microspheres, encapsulating the drug, and coating the fabric has also been studied. PMID:22127843

  13. Optimization on the thermal and tensile influencing factors of polyurethane-based polyester fabric composites

    Microsoft Academic Search

    Qian-Shu Lu; Lan-Hui Sun; Zhen-Guo Yang; Xiao-Hui Li; Shi-Lei Jin

    2010-01-01

    In order to obtain an optimal PU based polyester fabric composites orienting to applications, the composites with different ratios of bi-component PU adhesive and different structural inorganic fillers were fabricated and characterized thermally and mechanically, and the mechanisms were theoretically discussed in details; in particular, the tensile performances with different loading directions have also been studied. In the present approach,

  14. Influence of chemical surface modification on the properties of biodegradable jute fabrics—polyester amide composites

    Microsoft Academic Search

    A. K Mohanty; M. A Khan; G Hinrichsen

    2000-01-01

    The chemical surface modifications of jute fabrics involving bleaching, dewaxing, alkali treatment, cyanoethylation and vinyl grafting are made in view of their use as reinforcing agents in composites based on a biodegradable polyester amide matrix, BAK 1095. The effect of different fibre surface treatments and fabric amounts on the performance of resulting composites are investigated. The mechanical properties of composites

  15. Effect of bonding systems and antioxidants on the adhesion between EPDM rubber and polyester fabric

    Microsoft Academic Search

    N. A. Darwish; A. A. El-Wakil; Ahmed I. Abou-Kandil

    2009-01-01

    Ethylene propylene diene monomer (EPDM) rubber mixes containing different types of bonding materials and various commercial antioxidants were used to evaluate the adhesion of EPDM rubber to polyester fabric. A new antioxidant was prepared by graft copolymerization of 1, 5-diaminonaphthalene (DAN) onto natural rubber (NR) in order to investigate its effect on adhesion. It was observed that EPDM mixes containing

  16. Effect of polymeric additives on the formation and properties of polyaniline films on polyester fabrics

    Microsoft Academic Search

    Ya-Ping Zhao; Zai-Sheng Cai; Xiao-Lan Fu

    2011-01-01

    Electrically conductive films based on polyaniline (PANI) and polyethylene glycol (PEG) molecules of different chain length were synthesized on polyester textiles (PET) through in situ polymerization. Fabric supports were placed in the monomer bath in the presence of polymeric additive firstly and then immersed into the oxidant solution to initiate the reaction. Influence of the PEG segment length on monomer

  17. Effect of polymeric additives on the formation and properties of polyaniline films on polyester fabrics

    Microsoft Academic Search

    Ya-Ping Zhao; Zai-Sheng Cai; Xiao-Lan Fu

    2012-01-01

    Electrically conductive films based on polyaniline (PANI) and polyethylene glycol (PEG) molecules of different chain length were synthesized on polyester textiles (PET) through in situ polymerization. Fabric supports were placed in the monomer bath in the presence of polymeric additive firstly and then immersed into the oxidant solution to initiate the reaction. Influence of the PEG segment length on monomer

  18. Thermal properties of hybrid lignocellulosic fabric-reinforced polyester matrix composites

    Microsoft Academic Search

    O. L. S. Alsina; L. H. de Carvalho; F. G. Ramos Filho; J. R. M. d'Almeida

    2005-01-01

    The thermal diffusivity, thermal conductivity and specific heat of jute\\/cotton, sisal\\/cotton and ramie\\/cotton hybrid fabric-reinforced unsaturated polyester composites were determined. These properties were measured both parallel and perpendicular to the plane of the fabrics. The results obtained show that higher values were obtained parallel to the plane of the fibers. Sisal\\/cotton composites show a particular behavior, with thermal properties very

  19. Multifunctional finishing of cellulosic/polyester blended fabrics.

    PubMed

    Ibrahim, N A; Eid, B M; Youssef, M A; Ibrahim, H M; Ameen, H A; Salah, A M

    2013-09-12

    Innovative/efficient finishing systems for imparting multi-functional properties to cotton/polyester and viscose/polyester blends were developed. Factors affecting the extent of functionalization including type and concentration of the nano-hybrid, i.e. silver nanoparticles/polyvinyl pyrolidone hybrid (Ag-NP's/PVP) or zinc oxide nanoparticles/hyperbranched polyamide-amine hybrid (ZnO-NP's/HBPAA), concentration of Basic Blue 9, or chitosan and sequence of treatment using citric acid as cross-linker were reported. Loading of ?-CD, with its hydrophobic cavities, onto the cross-linked substrates and subsequent treatment with Neem-oil, Lavender-oil or 4-hydroxybenzophenone was also studied. The obtained products exhibit a remarkable easy care, antibacterial and/or UV-blocking functional properties. The improvement in the imparted properties and durability to wash is governed by type and amount of loaded active ingredients. Mode of interactions was suggested, and surface modifications together with composition of selected samples were also confirmed by SEM images and EDX spectra. PMID:23911516

  20. Comparison of the analytical performance of electrophoresis microchannels fabricated in PDMS, glass, and polyester-toner

    PubMed Central

    Coltro, Wendell Karlos Tomazelli; Lunte, Susan M.; Carrilho, Emanuel

    2008-01-01

    This paper compares the analytical performance of microchannels fabricated in PDMS, glass, and polyester-toner for electrophoretic separations. Glass and PDMS chips were fabricated using well-established photolithographic and replica-molding procedures, respectively. PDMS channels were sealed against three different types of materials: native PDMS, plasma-oxidized PDMS, and glass. Polyester-toner chips were micromachined by a direct-printing process using an office laser printer. All microchannels were fabricated with similar dimensions according to the limitations of the direct-printing process (width/depth 150 ?m/12 ?m). LIF was employed for detection to rule out any losses in separation efficiency due to the detector configuration. Two fluorescent dyes, coumarin and fluorescein, were used as model analytes. Devices were evaluated for the following parameters related to electrophoretic separations: EOF, heat dissipation, injection reproducibility, separation efficiency, and adsorption to channel wall. PMID:19025869

  1. Polymer–Metal Complexes Obtained by Radiation?Induced Grafting Process onto Polyester Fabrics

    Microsoft Academic Search

    M. H. Zohdy; M. Madani

    2004-01-01

    This paper reports the preparation of chelating copolymers via grafting of acrylic acid, and\\/or acrylamide onto polyester microfiber (PETMF) fabrics using a ??radiation technique. The effect of monomer concentration on the grafting process at irradiation dose 20?kGy was studied. The prepared graft chains (PETMF?g?AA), (PETMF?g?AAm), and (PETMF?g?PAAc\\/PAAm) acted as chelating sites for some selected transition metal ions. The effect of

  2. Thermo-physiological comfort characteristics of polyester air-jet-textured and cotton-yarn fabrics

    Microsoft Academic Search

    R. S. Rengasamy; B. R. Das; Y. B. Patil

    2009-01-01

    Air-jet-textured polyester yarns were produced using two feed yarns differing in filament fineness and number of filaments. By varying the overfed rates of feed yarns and changing their positions in core and effect, five textured yarns were produced. Woven fabrics were prepared using these textured yarns as weft and cotton yarns in warp. To study the effect of air-jet-texturing parameters

  3. Cationization and gamma irradiation effects on the dyeability of polyester fabric towards disperse dyes

    NASA Astrophysics Data System (ADS)

    Zohdy, Maged H.

    2005-06-01

    The effect of hydrazine hydrate (HZH) treatment and/or gamma irradiation on the dyeing, mechanical and thermal properties of polyester fabrics (PET) was studied. The different factors that may affect the dyeing performance, such as concentrations of HZH, benzyl alcohol and pH values, were investigated. In this regard, the colour strength of untreated polyester fabrics dyed with the dyestuffs Dispersol blue BR, Dispersol orange B2R and Dispersol red B2B was found to be 10.34, 10.76 and 10.12 compared to 24.61, 24.90 and 23.00 in the case of irradiated and HZH-treated polyester fabrics, respectively. These colour strength values were achieved by preirradiation at a dose of 75 kGy followed by treatment with 15 ml l-1 of HZH. Thermogravimetric analysis (TGA) showed that the thermal decomposition stability was improved by using gamma irradiation and the treatment with HZH as indicated by the calculated activation energies. FT-IR spectroscopy showed that the treatment with HZH acts as cationizer prior to dyeing with disperse dyes.

  4. Effect of weight reduction pre-treatment on the electrical and thermal properties of polypyrrole coated woven polyester fabrics

    Microsoft Academic Search

    H. Tavanai; A. Kaynak

    2007-01-01

    Weight reduction increased the amount of deposited polypyrrole (PPy) on the polyester (PET) fiber surface, leading to a considerable decrease in electrical resistance and improved heat generation capacity for the PPy coated PET fabrics. Application of dc voltages to an insulated roll of PPy-coated fabric increased the temperature to about 90°C. This showed the suitability of these fabrics for heating

  5. Surface functionalization of viscose and polyester fabrics toward antibacterial and coloration properties.

    PubMed

    El-Gabry, L K; Allam, O G; Hakeim, O A

    2013-01-30

    Nanoparticles have been increasingly used to improve the properties of textile fabrics. Viscose and polyester fabrics are treated with SiO(2) nanoparticle by another technique than the conventional sol-gel method in presence of binder (acrylate based copolymer). The effect of the content of SiO(2) nanoparticle on the physical properties of the treated fabrics such as moisture regain, tensile strength and elongation % were investigated. Furthermore, the antibacterial activity and coloration properties of pretreated fabrics were evaluated. Characterizations of pretreated samples by infrared spectroscopy and scanning electron microscopy were also conducted. The results show that the physical and coloration properties of pretreated samples were improved. The treated viscose fabric showed outstanding antibacterial performance against both Escherichia coli (G-) and Staphylococcus aureus (G+). Excellent durability of the treatment to repeated home laundering toward antibacterial and coloration properties was obtained in presence of binder. PMID:23218305

  6. Surface Modification of Polyester Fabric by Non-Thermal Plasma Treatment

    NASA Astrophysics Data System (ADS)

    Lima da Silva, R. C.; Alves, C., Jr.; Nascimento, J. H.; Neves, J. R. O.; Teixeira, V.

    2012-12-01

    In the present study it was carried out a surface modification of polyester fabric by plasma treatment with aim of providing hidrophilicity to fabric. In the process it were used three different gaseous atmosphere with mixtures of argon, nitrogen and/or oxygen [(1) Ar + N2 (4:2), (2) Ar + N2 + O2 (4:2:2) and N2 + O2 (2:0.6)] and maintained others parameters such as pressure, current and time of treatment fixed at 1.35 mBar, 0.08 A and 30 minutes, respectively. The plasma treatment was monitored by optical emission spectroscopy (OES) to identify the species presents in the plasma reactor. Chemical changes in the fabric surface after plasma treatments were determined by Fourier Transform Infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). Wicking properties were used to evaluate hydrophilicity of the fabric. Wicking measurement showed that the hydrophilicity of polyester fabric was remarkably improved after treatment and was explained by XPS analysis indicating higher presence of functional groups containing nitrogen and oxygen.

  7. Water-based chitosan/melamine polyphosphate multilayer nanocoating that extinguishes fire on polyester-cotton fabric.

    PubMed

    Leistner, Marcus; Abu-Odeh, Anas A; Rohmer, Sarah C; Grunlan, Jaime C

    2015-10-01

    Polyester-cotton (PECO) blends are widely used in the textile industry because they combine the softness of cotton and the strength and durability of polyester. Unfortunately, both fiber types share the disadvantage of being flammable. The layer-by-layer coating technique was used to deposit a highly effective flame retardant (melamine polyphosphate) from water onto polyester-cotton fabric. Soluble melamine and sodium hexametaphosphate form this water-insoluble flame retardant during the coating procedure. This unique nanocoating imparts self-extinguishing properties to PECO with only 12% relative coating weight. Vertical flame testing, pyrolysis combustion flow calorimetry (PCFC), thermogravimetric analysis (TGA), and scanning electron microscopy were used to evaluate the quality of the coating as well as its flame retardant performance. A combination of both condensed and gas-phase activity appears to be the reason for this effective flame retardancy. Degradation pathways of both cotton and polyester are affected by the applied coating, as shown by PCFC and TGA. Use of environmentally benign and non-toxic chemicals, and the ease of layer-by-layer deposition, making this coating an industrially feasible alternative to render polyester-cotton fabric self-extinguishing. PMID:26076621

  8. Effects of undoped and manganese-doped zinc oxide nanoparticles on the colour fading of dyed polyester fabrics

    Microsoft Academic Search

    Lu Sun; John A. Rippon; Peter G. Cookson; Olga Koulaeva; Xungai Wang

    2009-01-01

    This paper describes the effects of applying coatings of an acrylic polymer containing nanoparticles of zinc oxide (ZnO) on the fading rate in artificial sunlight of polyester fabrics dyed with disperse dyes containing anthraquinone and benzopyran chromophores. Factors affecting the transparency and UV absorbance of the coatings are discussed. Removing the UV component of sunlight with ZnO nanoparticles markedly decreased

  9. Characterization of E-glass/polyester woven fabric composite laminates and tubes

    SciTech Connect

    Guess, T.R.; Reedy, E.D. Jr.; Stavig, M.E.

    1995-12-01

    This report describes an experimental study that supported the LDRD program ``A General Approach for Analyzing Composite Structures``. The LDRD was a tightly coupled analytical / experimental effort to develop models for predicting post-yield progressive failure in E-glass fabric/polyester composites subjected to a variety of loading conditions. Elastic properties, fracture toughness parameters, and failure responses were measured on flat laminates, rings and tubes to support the development and validation of material and structural models. Test procedures and results are presented for laminates tested in tension, compression, flexure, short beam shear, double cantilever beam Mode I fracture toughness, and end notched flexure Mode II fracture toughness. Structural responses, including failure, of rings loaded in diametral compression and tubes tested in axial compression, are also documented.

  10. Development and assessment of a biodegradable solvent cast polyester fabric small-diameter vascular graft

    PubMed Central

    Brandes, Zachary R; Jonas, Richard A.; Fisher, John P.

    2014-01-01

    Adjusting the mechanical properties of polyester-based vascular grafts is crucial to achieving long-term success in vivo. While previous studies using a fabric-based approach have achieved some success, a central issue with pure poly(lactic acid) (PLA) or poly(glycolic acid) (PGA) grafts sealed with poly(DL-caprolactone-co-lactic acid) (P(CL/LA)) has been stenosis. Intimal hyperplasia, a leading cause of stenosis, can be caused by the mechanical incompatibility of synthetic vascular grafts. Investigating the performance of poly(glycolic-co-lactic acid) grafts (PGLA) could lead to insight into whether graft stenosis stems from mechanical issues such as non-compliance and unfavorable degradation times. This could be achieved by examining grafts with tunable mechanical properties between the ranges of such properties in pure PGA and PLA based grafts. In this study, we examined PGLA-based grafts sealed with different P(CL/LA) solutions to determine the PGLA-P(CL/LA) grafts' mechanical properties and tissue functionality. Cell attachment and proliferation on graft surfaces were also observed. For in vivo assessment, grafts were implanted in a mouse model. Mechanical properties and degradation times appeared adequate compared to recorded values of vessels used in autograft procedures. Initial neotissue formation was observed in the grafts and patency maintained during the pilot study. This study presents a ~1mm diameter degradable graft demonstrating suitable mechanical properties and in vivo pilot study success, enabling further investigation into the tuning of mechanical properties to reduce complications in degradable polyester fabric-based vascular grafts. PMID:23852776

  11. Fabrication and characterization of biomimetic multichanneled crosslinked-urethane-doped polyester tissue engineered nerve guides.

    PubMed

    Tran, Richard T; Choy, Wai Man; Cao, Hung; Qattan, Ibrahim; Chiao, Jung-Chih; Ip, Wing Yuk; Yeung, Kelvin Wai Kwok; Yang, Jian

    2014-08-01

    Biomimetic scaffolds that replicate the native architecture and mechanical properties of target tissues have been recently shown to be a very promising strategy to guide cellular growth and facilitate tissue regeneration. In this study, porous, soft, and elastic crosslinked urethane-doped polyester (CUPE) tissue engineered nerve guides were fabricated with multiple longitudinally oriented channels and an external non-porous sheath to mimic the native endoneurial microtubular and epineurium structure, respectively. The fabrication technique described herein is highly adaptable and allows for fine control over the resulting nerve guide architecture in terms of channel number, channel diameter, porosity, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers and displayed an ultimate peak stress of 1.38 ± 0.22 MPa with a corresponding elongation at break of 122.76 ± 42.17%, which were comparable to that of native nerve tissue. The CUPE nerve guides were also evaluated in vivo for the repair of a 1 cm rat sciatic nerve defect. Although histological evaluations revealed collapse of the inner structure from CUPE TENGs, the CUPE nerve guides displayed fiber populations and densities comparable with nerve autograft controls after 8 weeks of implantation. These studies are the first report of a CUPE-based biomimetic multichanneled nerve guide and warrant future studies towards optimization of the channel geometry for use in neural tissue engineering. PMID:24115502

  12. Non-destructive and fast identification of cotton-polyester blend fabrics by the portable near-infrared spectrometer.

    PubMed

    Li, Wen-xia; Li, Feng; Zhao, Guo-liang; Tang, Shi-jun; Liu, Xiao-ying

    2014-12-01

    A series of 376 cotton-polyester (PET) blend fabrics were studied by a portable near-infrared (NIR) spectrometer. A NIR semi-quantitative-qualitative calibration model was established by Partial Least Squares (PLS) method combined with qualitative identification coefficient. In this process, PLS method in a quantitative analysis was used as a correction method, and the qualitative identification coefficient was set by the content of cotton and polyester in blend fabrics. Cotton-polyester blend fabrics were identified qualitatively by the model and their relative contents were obtained quantitatively, the model can be used for semi-quantitative identification analysis. In the course of establishing the model, the noise and baseline drift of the spectra were eliminated by Savitzky-Golay(S-G) derivative. The influence of waveband selection and different pre-processing method was also studied in the qualitative calibration model. The major absorption bands of 100% cotton samples were in the 1400~1600 nm region, and the one for 100% polyester were around 1600~1800 nm, the absorption intensity was enhancing with the content increasing of cotton or polyester. Therefore, the cotton-polyester's major absorption region was selected as the base waveband, the optimal waveband (1100~2500 nm) was found by expanding the waveband in two directions (the correlation coefficient was 0.6, and wave-point number was 934). The validation samples were predicted by the calibration model, the results showed that the model evaluation parameters was optimum in the 1100~2500 nm region, and the combination of S-G derivative, multiplicative scatter correction (MSC) and mean centering was used as the pre-processing method. RC (relational coefficient of calibration) value was 0.978, RP (relational coefficient of prediction) value was 0.940, SEC (standard error of calibration) value was 1.264, SEP (standard error of prediction) value was 1.590, and the sample's recognition accuracy was up to 93.4%. It showed that the cotton-polyester blend fabrics could be predicted by the semi-quantitative-qualitative calibration model. PMID:25881417

  13. Effects of Household Fabric Softeners on Thermal Comfort of Cotton and Polyester Fabrics After Repeated Launderings

    Microsoft Academic Search

    Jessie H. Chen-Yu; Jiangman Guo; Beverly Kemp-Gatterson

    2009-01-01

    The purpose of this study was to explore the effects of household fabric softeners on the thermal comfort of fabrics after repeated laundering cycles. Several textile properties can influence thermal comfort of a garment. This study focuses on two of these properties, air permeability and water vapor transmission. A 3 × 2 × 3 experimental design was developed with three

  14. Improvement in hydrophobicity of polyester fabric finished with fluorochemicals via aminolysis and comparing with nano-silica particles

    Microsoft Academic Search

    Zahra Mazrouei-Sebdani; Akbar Khoddami; Shadpour Mallakpour

    2011-01-01

    For the fabrication of the “lotus-type” fibers, a combination of two major requirements, low surface energy and the magnified\\u000a of the degree of roughness, should be utilized. In this research, the possible surface roughening effect of aminolysis of\\u000a the polyester fibers was applied to manipulated surface topography while fluorocarbon polymer layer generates low surface\\u000a energy. The results were compared with

  15. COTTON-POLYESTER FABRIC BLEND ANALYSIS BY NEAR INFRARED (NIR) SPECTROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near Infrared (NIR) techniques have been used extensively to measure key physical and chemical properties of textile materials and textile auxiliaries, including the fiber blending ratio in cotton-polyester (PET) blend fibers and yarns. Interest had grown in the measurement of the fiber blend conte...

  16. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    NASA Astrophysics Data System (ADS)

    Misri, S.; Leman, Z.; Sapuan, S. M.; Ishak, M. R.

    2010-05-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  17. Fabrication of thermoset polyester microfluidic devices and embossing masters using rapid prototyped polydimethylsiloxane molds

    Microsoft Academic Search

    Gina S. Fiorini; Gavin D. M. Jeffries; David S. W. Lim; Christopher L. Kuyper; Daniel T. Chiu

    2003-01-01

    Plastics are increasingly being used for the fabrication of Lab-on-a-Chip devices due to the variety of beneficial material properties, affordable cost, and straightforward fabrication methods available from a range of different types of plastics. Rapid prototyping of polydimethylsiloxane (PDMS) devices has become a well-known process for the quick and easy fabrication of microfluidic devices in the research laboratory; however, PDMS

  18. Preparation and properties of polyester fabrics grafted with O-carboxymethyl chitosan.

    PubMed

    Lv, Jingchun; Zhou, Qingqing; Liu, Guoliang; Gao, Dawei; Wang, Chunxia

    2014-11-26

    Carboxymethyl chitosan (CMCS) was prepared with a view to develop a multifunctional finish on saponified polyethylene terephthalate (PET) fabric. CMCS was synthesized by chemical reaction with chloroacetic acid, and its chemical structure was characterized by Fourier Transform Infrared Spectrum (FTIR) and nuclear magnetic resonance (NMR). CMCS was grafted on saponified PET fabric using 3-(3-dimethylaminopropyl)-1-ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS) and polyethylenimine (PEI)/glutaraldehyde (GA) as cross-linking agent. FTIR, scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analyses confirmed CMCS grafting on saponified PET fabric surface. TGA indicated saponification and CMCS grafting did not affect thermal property of PET fabric. The CMCS grafting greatly improved wettability, antistatic property of saponified PET fabric without harmful effect on their physico-mechanical properties. PMID:25256493

  19. The property and formation mechanism of unsaturated polyester–layered silicate nanocomposite depending on the fabrication methods

    Microsoft Academic Search

    D. J. Suh; Y. T. Lim; O. O. Park

    2000-01-01

    The properties of unsaturated polyester (UP)\\/montmorillonite (MMT) nanocomposite greatly depend on the preparation procedure because of the chemical reactions and physical interactions involved. To investigate the properties and formation mechanism of UP\\/MMT nanocomposite, samples were prepared by two different mixing methods. The first method, simultaneous mixing, is similar to the method used for preparing the conventional unsaturated polyester and filler

  20. Ink jet printing of bio-treated linen, polyester fabrics and their blend.

    PubMed

    El-Hennawi, H M; Shahin, A A; Rekaby, M; Ragheb, A A

    2015-03-15

    Cellulosic fabrics were surface modified using Brewer's yeast filtrate and cellulase enzymes (Valumax A828, Valumax A356) to enhance its affinity to ink jet printing. The effect of enzymes on the surface structure and morphology of the cellulosic fabrics used has been illustrated using scanning electron microscope. Related test as tensile strength have been measured. The bio-treated cellulosic fabrics were digitally printed and the colour strength (K/S) and % increase in K/S were measured. Effect of different conditions (enzyme concentration, temperature and time) was investigated to obtain the optimum condition of each enzyme for each fabric that or which was indicated by higher colour strength. Results show a noticeable increase in the K/S especially for cellulosic linen and its blend compared to the standard samples. The optimum conditions to obtain the higher K/S by using Brewer's yeast filtrate and the other two cellulase enzymes in the pre-treatment of ink jet samples were obtained. PMID:25542129

  1. Some mechanical properties of untreated jute fabric-reinforced polyester composites

    Microsoft Academic Search

    T. Munikenche Gowda; A. C. B. Naidu; Rajput Chhaya

    1999-01-01

    This research work is concerned with the evaluation of the mechanical properties—modulus, Poisson's ratio and strength—of woven jute fabric-reinforced composites. The specimens are prepared using hand lay-up techniques as per the ASTM standard. This is the first report by any single group of researchers in which tensile strength, compressive strength, flexural strength, impact strength, inplane shear strength, interlaminar shear strength

  2. Insulin and heparin co-immobilized 3D polyester fabrics for the cultivation of fibroblasts in low-serum media.

    PubMed

    Türko?lu Sa?mazel, Hilal; Aday, Sezin; Gümü?derelio?lu, Menem?e

    2007-08-01

    Insulin and/or heparin immobilized/co-immobilized non-woven polyester fabric (NWPF) discs were developed for the cultivation of L929 mouse fibroblasts in low-serum media. At first, NWPF discs were hydrolyzed to obtain a carboxylic acid group-introduced matrix (NWPF-hydrolyzed). Insulin and heparin co-immobilized NWPF (NWPF-insulin-heparin) was prepared by the grafting of PEO onto NWPF-hydrolyzed disc (NWPF-PEO), followed by the reaction first with insulin and then heparin. In the presence of spacer arm, PEO, the amount of immobilized insulin molecules significantly increased from 6.96 to 84.45 microg/cm(2). The amount of heparin bound to the NWPF-PEO (5.93 microg/cm(2)) was higher than that of the insulin immobilized surface (4.59 microg/cm(2)). Insulin and heparin immobilized NWPF discs were observed with fluorescence microscopy by labeling the insulin and heparin with 8-anilino-1-naphthalene sulfonic acid (ANS) or fluorescein isothiocyanate (FITC), respectively. L929 fibroblasts were used to check the cell adhesion and cell growth capabilities of modified NWPF discs in low-serum media (containing 5% fetal bovine serum). Optical photographs showed that after 2nd day of the culture, fibroblastic cells spread along the length of modified fibers, eventually filling the interfiber space. At the end of 6-day growth period, cell yield in the presence of immobilized heparin was a little bit higher than that of the immobilized insulin. Co-immobilized (insulin/heparin) NWPF discs did not accelerate the cell growth as well as insulin or heparin immobilized discs. PMID:17576003

  3. Mechanical properties and fabrication of small boat using woven glass\\/sugar palm fibres reinforced unsaturated polyester hybrid composite

    Microsoft Academic Search

    S Misri; Z Leman; S M Sapuan; M R Ishak

    2010-01-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass\\/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres.

  4. Tensile and hardness tests on polyester-fabric-reinforced neoprene-rubber seals used in Pickering NGS A pressure-relief-duct expansion/contraction joints. Report No. 90-173-K

    SciTech Connect

    Lewak, R.J.

    1990-01-01

    This report presents the results of tests conducted on tensile test specimens cut from sections of both spliced and non-spliced polyester fabric reinforced neoprene rubber material which had been used as seals on the contraction joints of the Pickering Nuclear Generating Station A pressure relief duct. The specimens were tested for durometer hardness and then tensile-tested to destruction.

  5. A robust super-paramagnetic TiO2:Fe3O4:Ag nanocomposite with enhanced photo and bio activities on polyester fabric via one step sonosynthesis.

    PubMed

    Harifi, Tina; Montazer, Majid

    2015-11-01

    High intensity ultrasound was used for the synthesis and simultaneous deposition of TiO2:Fe3O4:Ag nanocomposites on polyester surface providing a feasible route for imparting magnetic and enhanced antibacterial and self-cleaning activities with controllable hydrophilicity/hydrophobicity at low temperature. Synergistic impact of sonochemistry and physical effects of ultrasound originating from implosive collapse of bubbles were responsible for the formation and adsorption of nanomaterials on the fabric surface during ultrasound irradiation. The increase in photocatalytic activity of TiO2 was obtained attributing to the co-operation of iron oxide and silver nanoparticles nucleated on TiO2 surface boosting the electron-hole pair separation and prolonging their recombination rate. The process was further optimized in terms of reagents concentrations including Fe(2+)/TiO2 and Ag/TiO2 molar ratios using central composite design in order to achieve the best self-cleaning property of the treated fabric. The magnetic measurements indicated the super-paramagnetic behavior of the treated fabric with saturation magnetization of 4.5(emu/g). Findings suggest the potential of the proposed facial method in producing an intelligent fabric with durable multi-functional activities that can be suitable for various applications including medical, military, bio-separation, bio-sensors, magneto graphic printing, magnetic screens and magnetic filters. PMID:25899439

  6. Changes of pulling-out length and shrinkage ratio in polyester\\/spandex power net warp knitted fabrics

    Microsoft Academic Search

    Choon Gil Lee

    2006-01-01

    Power net fabric is one of the highly extensible two-way fabrics. Power net structure shows special characteristics in the\\u000a wearing of final functional clothes. This research evaluated effects of treatment temperature on proportional extensibility\\u000a and shrinkage ratio of spandex at a given wale length. As treatment temperature increased, extensibility increased proportionally\\u000a to the standard length of the sample and the

  7. Synthesis, biological activity and dyeing performance of some novel azo disperse dyes incorporating pyrazolo[1,5-a]pyrimidines for dyeing of polyester fabrics

    NASA Astrophysics Data System (ADS)

    Sayed, Ahmed Z.; Aboul-Fetouh, Mahmoud S.; Nassar, Hesham S.

    2012-02-01

    Several novel pyrazolopyrimidine azo compounds were achieved from diazotization of 4-aminoacetanilide and coupling with malononitrile and then refluxed with hydrazine hydrate to furnish 3,5-diamino-4-(4-acetamidophenylazo)-1H-pyrazole. The later compound was diazotized and coupled with substituted ?-cyanocinnamate, ?-cyanocinnamonitrile, 2-cyano-3-ethoxyacrylic acid ethyl ester, chalcones and ethylacetoacetate to produce novel dyestuffs. Structures of the dyes were fully characterized by using FT-IR, 1H NMR, mass spectroscopy and elemental analysis. The dyes were applied to polyester fiber, affording satisfactory results and showed biological activity towards various microorganisms.

  8. Microwave processing of polyester and polyester-glass composites

    SciTech Connect

    Hottong, U.; Wei, J.; Dhulipla, R.; Hawley, M.C.

    1992-04-27

    Polyester resins and polyester/glass composites were processed using 2.45GHz microwave radiation in single mode resonant cavities. An alkyl phthalate polyester resin (diluted with vinyltoluene) and a unidirectional glass fiber/polyester (diallyl phthalate) prepreg were examined. In the study of polymerization kinetics, a 6 inch diameter resonant cavity and a thin film technique were used to cure neat resin samples. Thermal curing was carried out for comparison. The extents of cure of the samples were determined using Fourier Transform Infrared Spectrophotometry (FTIR). Faster reaction rates microwave processing; polyester; polyester/glass composite; extent of cure; dielectric measurement; mode switching.

  9. Polyesters by Photochemical Cyclopolymerization

    NASA Technical Reports Server (NTRS)

    Meador, Michael A. (Inventor)

    2002-01-01

    The polyesters of this invention are derived from a Diels-Alder cyclopolymerization of a photochemically generated bisdiene with dienophiles, such as di(acrylates), tri (acrylates), di(methacrylates), tri(methacrylates) and mixtures thereof with mono(methacrylates) or mono(acrylate) end-caps. Irradiation of one or more diketones produces two distinct hydroxy o-quinodimethane (photoenol) intermediates. These intermediates are trapped via a Diels-Alder cycloaddition with appropriate dienophiles, e.g., di(acrylates) to give the corresponding in polyesters quantitative yields. When di(acrylates), tri(acrylates) and di and tri(methacrylates) or mixtures thereof with monoacrylate end-caps are used as the dienophile, the resulting polyesters have glass transition temperatures (Tg) as high as 200 C. Polyesters films can be prepared by ultraviolet irradiation of high solids content varnishes of the monomers in a small amount of solvent, e.g., cyclohexanone, dimethyl formamide, N-methylpyrollidone and the like. These polyesters, i.e. polyesters are characterized as having high glass transition temperatures, good mechanical properties and improved processing in the manufacture of composites, adhesives, electronic materials and films.

  10. Polyesters in higher plants.

    PubMed

    Kolattukudy, P E

    2001-01-01

    Polyesters occur in higher plants as the structural component of the cuticle that covers the aerial parts of plants. This insoluble polymer, called cutin, attached to the epidermal cell walls is composed of interesterified hydroxy and hydroxy epoxy fatty acids. The most common chief monomers are 10,16-dihydroxy C16 acid, 18-hydroxy-9,10 epoxy C18 acid, and 9,10,18-trihydroxy C18 acid. These monomers are produced in the epidermal cells by omega hydroxylation, in-chain hydroxylation, epoxidation catalyzed by P450-type mixed function oxidase, and epoxide hydration. The monomer acyl groups are transferred to hydroxyl groups in the growing polymer at the extracellular location. The other type of polyester found in the plants is suberin, a polymeric material deposited in the cell walls of a layer or two of cells when a plant needs to erect a barrier as a result of physical or biological stress from the environment, or during development. Suberin is composed of aromatic domains derived from cinnamic acid, and aliphatic polyester domains derived from C16 and C18 cellular fatty acids and their elongation products. The polyesters can be hydrolyzed by pancreatic lipase and cutinase, a polyesterase produced by bacteria and fungi. Catalysis by cutinase involves the active serine catalytic triad. The major function of the polyester in plants is as a protective barrier against physical, chemical, and biological factors in the environment, including pathogens. Transcriptional regulation of cutinase gene in fungal pathogens is being elucidated at a molecular level. The polyesters present in agricultural waste may be used to produce high value polymers, and genetic engineering might be used to produce large quantities of such polymers in plants. PMID:11217409

  11. Microfabricated polyester conical microwells for cell culture applications†

    PubMed Central

    Selimovi?, Šeila; Piraino, Francesco; Bae, Hojae; Rasponi, Marco; Redaelli, Alberto

    2012-01-01

    Over the past few years there has been a great deal of interest in reducing experimental systems to a lab-on-a-chip scale. There has been particular interest in conducting high-throughput screening studies using microscale devices, for example in stem cell research. Microwells have emerged as the structure of choice for such tests. Most manufacturing approaches for microwell fabrication are based on photolithography, soft lithography, and etching. However, some of these approaches require extensive equipment, lengthy fabrication process, and modifications to the existing microwell patterns are costly. Here we show a convenient, fast, and low-cost method for fabricating microwells for cell culture applications by laser ablation of a polyester film coated with silicone glue. Microwell diameter was controlled by adjusting the laser power and speed, and the well depth by stacking several layers of film. By using this setup, a device containing hundreds of microwells can be fabricated in a few minutes to analyze cell behavior. Murine embryonic stem cells and human hepatoblastoma cells were seeded in polyester microwells of different sizes and showed that after 9 days in culture cell aggregates were formed without a noticeable deleterious effect of the polyester film and glue. These results show that the polyester microwell platform may be useful for cell culture applications. The ease of fabrication adds to the appeal of this device as minimal technological skill and equipment is required. PMID:21614380

  12. Oxazoline polyester coating resins

    Microsoft Academic Search

    W. J. deJarlais; L. E. Gast; J. C. Cowan

    1967-01-01

    Oxazoline polyester resins were prepared by reaction of oxazoline diols from linseed acids and tris (hydroxymethyl) aminomethane\\u000a with each of five dibasic acids (adipic, dimer, fumaric, itaconic and maleic). Certain resins were dissolved in isopropyl\\u000a alcohol to give solutions infinitely water dilutable when the free carboxyl was neutralized with an amine. Film properties\\u000a of resins cast on steel plates were

  13. Stabilized unsaturated polyesters

    NASA Technical Reports Server (NTRS)

    Vogl, O.; Borsig, E. (inventors)

    1985-01-01

    An unsaturated polyester, such as propylene glycolmaleic acid phthalic acid prepolymer dissolved in styrene is interpolymerized with an ultraviolet absorber and/or an antioxidant. The unsaturated chain may be filled with H or lower alkyl such as methyl and tertiary alkyl such as tertiary butyl. A polymer stable to exposure to the outdoors without degradation by ultraviolet radiation, thermal and/or photooxidation is formed.

  14. Polyesters in Higher Plants

    Microsoft Academic Search

    Pappachan E. Kolattukudy

    Polyesters occur in higher plants as the structural component of the cuticle that covers the aerial parts of plants. This\\u000a insoluble polymer, called cutin, attached to the epidermal cell walls is composed of interesterified hydroxy and hydroxy epoxy\\u000a fatty acids. The most common chief monomers are 10, 16-dihydroxy C16 acid, 18-hydroxy-9, 10 epoxy C18 acid, and 9, 10, 18-trihydroxy C18

  15. Radiation Reactions of Unsaturated Polyesters

    Microsoft Academic Search

    A. Charlesby; V. Wycherley; T. T. Greenwood

    1958-01-01

    The polymerization of monomers containing more than one double bond may lead to the formation of crosslinked polymers. The monomers involved in this work were unsaturated polyesters. Ionizing radiation was found to initiate polymerization and, at the same time, lead to an insoluble network by causing crosslinking between the polyester chains. The effect of both low- and high-intensity radiation, additives,

  16. Future of microbial polyesters

    PubMed Central

    2013-01-01

    Numerous microorganisms accumulate polyesters classified as polyhydroxyalkanoates (PHAs) as carbon and energy storage material when the growth condition is unfavorable in the presence of excess carbon source. Natural PHAs typically consist of various (R)-hydroxycarboxylic acids, and exhibit different material properties depending on the monomer composition. Such diversity comes from different metabolic pathways operating in the cell, and thus generating different monomers. Even more diverse PHAs can be produced by metabolically engineered microorganisms, which leads to the biosynthesis of non-natural polyesters containing lactate as a monomer. In order to make PHAs as useful polymers in our daily life, their production cost should be significantly lowered and material properties should be compatible with those produced by petrochemical industries. Metabolic engineering can address these issues by developing microbial strains capable of producing PHAs of desired material properties with high productivity and yield from inexpensive carbon sources. This commentary aims at peeking into the future of PHAs, focusing on the possible metabolic engineering strategies to be taken to achieve these goals. PMID:23714196

  17. Pressure polymerization of polyester

    DOEpatents

    Maurer, Charles J. (Matthews, NC); Shaw, Gordon (Charlotte, NC); Smith, Vicky S. (Greer, SC); Buelow, Steven J. (Los Alamos, NM); Tumas, William (Los Alamos, NM); Contreras, Veronica (San Antonio, TX); Martinez, Ronald J. (Santa Cruz, NM)

    2000-08-29

    A process is disclosed for the preparation of a polyester polymer or polyester copolymer under superatmospheric pressure conditions in a pipe or tubular reaction under turbannular flow conditions. Reaction material having a glycol equivalents to carboxylic acid equivalents mole ratio of from 1.0:1 to 1.2:1, together with a superatmospheric dense gaseous medium are fed co-currently to the reactor. Dicarboxylic acid and/or diol raw materials may be injected into any of the reaction zones in the process during operation to achieve the overall desired mole ratio balance. The process operates at temperatures of from about 220.degree. C. to about 320.degree. C., with turbannular flow achieved before the polymer product and gas exit the reactor process. The pressure in the reaction zones can be in the range from 15 psia to 2500 psia. A polymer product having a DP of a greater than 40, more preferably at least about 70, is achieved by the transfer of water from the reacting material polymer melt to the gaseous medium in the reactor.

  18. Polyester based hybrid organic coatings

    NASA Astrophysics Data System (ADS)

    Wang, Xiaojiang

    Polyesters are a class of polymers widely used in organic coatings applications. In this work, four types of organic coatings based on polyester polyols were prepared: UV-curable polyester/poly(meth)acrylate coatings, thermal curable polyester polyurethane-urea coatings, thermal curable non-isocyanate polyurethane coatings, and UV-curable non-isocyanate polyurethane coatings. Polyester/poly(meth)acrylate block copolymers are synthesized using a combination of polycondensation and Atom-Transfer Radical Polymerization (ATRP). All block copolymers are characterized by means of Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). In the case of unsaturated-polyester-based block copolymers the main chain double bond in the polyester backbone remains almost unaffected during ATRP. The unsaturated block copolymers are crosslinkable and can form networks upon photo-irradiation in the presence of a suitable photoinitiator. These copolymers might be interesting candidates for coatings with better overall properties than those based on neat polyesters. Thermal curable polyester polyol based Polyurethane-Urea (PUU) coatings were formulated using Partially Blocked HDI isocyanurate (PBH), Isophorone Diamine (IPDA), and polyester polyol. As a comparison, the polyurethane coatings (PU) without adding IPDA were also prepared. The mechanical and viscoelastic properties of the PUU and PU coating were investigated by using tensile test and Dynamic Mechanical Thermal Analyzer (DMTA). It was found that PUU coating exhibited higher crosslink density, Tg, tensile modulus and strength than the corresponding PU coating. Thermal curable non-isocyanate polyurethane coatings were prepared by using polyamine and cyclic carbonate terminated polyester. Cyclic carbonate terminated polyester was synthesized from the reaction of the carbon dioxide and epoxidized polyester which was prepared from the polyester polyol. The properties of the epoxidized and cyclic carbonate terminated polyester were characterized by Brookfield viscometer, NMR and Fourier Transform Infrared spectroscopy (FTIR). UV-curable non-isocyanate polyurethane coatings were formulated by using Acrylated Polyester (APE) oligomer and Non-isocyanate Urethane Dimethacrylates (NUDMA) reactive diluents. The effect of the NUDMA on the viscosity of the APE oligomer was investigated by Brookfield viscometer. The photopolymerization kinetics of NUDMA reactive diluents were investigated by the real time FTIR. It was found that the polymerization conversion and maximum polymerization rate increase with increasing initiator concentration in the range from 0.5 % to 4.0 %. The formulation system containing both the APE oligomer and NUDMA reactive dilutes showed higher polymerization overall conversion and maximum polymerization rate than APE oligomer. After UV curing, the viscoelastic, tensile and thermal properties of the cured films were evaluated as a function of the reactive diluent by using DMTA, tensile test, Differential Scanning Calorimeters (DSC), and Thermal Gravimetric Analysis (TGA). In addition, coating properties such as pencil hardness, chemical resistance, impact resistance, and gloss were also investigated. It was found that crosslink density, storage and tensile modulus, pencil hardness, chemical resistance, gel content, total water absorption, and Tg were directly proportional to amount of the reactive diluents. Compared to the commercial Ethylene Glycol Dimethacrylate (EGDMA) reactive diluent, the NUDMA reactive diluents show significant improvements in impact resistance and elongation at break properties.

  19. Comparison of Thermomechanical Properties and Morphologies of Polyester Nanocomposite Fibers: PBT, PET, and PTT

    Microsoft Academic Search

    Jin-Hae Chang

    2008-01-01

    Nanocomposites of three different polyesters with dodecyltriphenyl-phosphonium-montmorillonite (C12PPh-MMT) organoclay are compared with respect to their thermal properties, mechanical properties, and morphologies. Poly(butylene terephthalate) (PBT), poly(ethylene terephthalate) (PET), and poly(trimethylene terephthalate) (PTT) were used as matrix polymers in the fabrication of polyester nanocomposite fibers. The variations in their properties with respect to both the organoclay content in the polymer matrix and

  20. Analysis of the failure of a polyester peripheral drive belt on the Mariner Mars 1971 flight tape recorder

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.

    1972-01-01

    A peripheral drive belt on the Mariner Mars 1971 tape recorder failed when a thin longitudinal strip separated off one edge. Analysis showed that the most probable cause of failure occurred from flexural fatigue initiating in mechanically weak locations which are introduced into the belt during fabrication. Methyl ethyl ketone, which is employed as a cleaning solvent during fabrication, was found to cause permanent reduction in engineering properties of polyester and could have contributed to the reduction of the fatigue resistance. Fatigue properties of the polyester drive belt are reviewed for the operating condition, as well as the sensitivity of polyester to cleaning solvents and the origin of mechanically weak locations.

  1. Polyester ?-assay chip for stem cell studies

    PubMed Central

    Piraino, Francesco; Selimovi?, Šeila; Adamo, Marco; Pero, Alessandro; Manoucheri, Sam; Bok Kim, Sang; Demarchi, Danilo; Khademhosseini, Ali

    2012-01-01

    The application of microfluidic technologies to stem cell research is of great interest to biologists and bioengineers. This is chiefly due to the intricate ability to control the cellular environment, the reduction of reagent volume, experimentation time and cost, and the high-throughput screening capabilities of microscale devices. Despite this importance, a simple-to-use microfluidic platform for studying the effects of growth factors on stem cell differentiation has not yet emerged. With this consideration, we have designed and characterized a microfluidic device that is easy to fabricate and operate, yet contains several functional elements. Our device is a simple polyester-based microfluidic chip capable of simultaneously screening multiple independent stem cell culture conditions. Generated by laser ablation and stacking of multiple layers of polyester film, this device integrates a 10?×?10 microwell array for cell culture with a continuous perfusion system and a non-linear concentration gradient generator. We performed numerical calculations to predict the gradient formation and calculate the shear stress acting on the cells inside the device. The device operation was validated by culturing murine embryonic stem cells inside the microwells for 5 days. Furthermore, we showed the ability to maintain the pluripotency of stem cell aggregates in response to concentrations of leukemia inhibitory factor ranging from 0 to ?1000 U/ml. Given its simplicity, fast manufacturing method, scalability, and the cell-compatible nature of the device, it may be a useful platform for long-term stem cell culture and studies. PMID:24278097

  2. Fabric

    NSDL National Science Digital Library

    N/A N/A (None; )

    2004-07-12

    Skin covers and protects the body. Your skin also has the ability to detect differences in texture. Each fabric in this image has a different texture, or feel. Receptors on your skin translate the texture into a message and relay the message to your brain so that you interpret the difference in textures from one fabric to another.

  3. Quantification of bacterial adherence on different textile fabrics

    Microsoft Academic Search

    Vidushi Bajpai; Apurba Dey; Subrata Ghosh; S. Bajpai; M. K. Jha

    2011-01-01

    This research studied the adherent behaviour of gram-negative Escherichia coli on different weft knitted textile fabrics made of cotton, polyester filaments and polyester (staple)-cotton blended yarn. We compared the bacterial adherence of 18-h-old E. coli cells on all the three types of fabrics under the same experimental conditions. The maximum adherence was found in cotton, followed by the polyester blend; the

  4. Which polyesters can mimic polyethylene?

    PubMed

    Stempfle, Florian; Ortmann, Patrick; Mecking, Stefan

    2013-01-11

    Self-metathesis of erucic acid by [(PCy(3))(?-C-C(3)H(4)N(2)Mes(2))Cl(2)Ru = CHPh] (Grubbs second- generation catalyst) followed by catalytic hydrogenation and purification via the ester yields 1,26-hexacosanedioate (>99% purity). Polyesterification with 1,26-hexacosanediol, generated from the diester, affords polyester-26,26, which features a T(m) of 114 °C (T(c) = 92 °C, ?H(m) = 160 J g(-1)). Ultralong-chain model polyesters-38,23 (T(m) = 109 °C) and -44,23 (T(m) = 111 °C), generated via multistep procedures including acyclic diene metathesis polymerization, underline that melting points of such aliphatic polyesters do not gradually increase with methylene sequence chain length. Available data suggest that to mimic linear polyethylenes thermal properties, even longer sequences, amounting to at least four times a fatty acid chain, fully incorporated in a linear fashion are required. PMID:23161497

  5. Effect of Charge and Hydrophobicity on Adsorption of Modified Starches on Polyester.

    PubMed

    Samu; Moulee; Kumar

    1999-12-15

    Polyester fabric (poly(ethylene terephthalate)) is a hydrophobic polymer. Its hydrophobic nature can be a disadvantage for certain applications like dyeing, finishing, detergency, etc. Physical or chemical modification of the polyester to make it more hydrophilic is therefore desirable for certain performance characteristics. Surface modification of polyester to make it hydrophilic can be achieved by adsorbing polymers on the polyester surface. Starch is a commonly available, hydrophilic polymer used in many textile applications that can be used to modify polyester. However, it needs to be chemically modified so that it can adsorb on the polyester fabric and physically modify the fabric characteristics. The polymers used in this study are two different modified starches-cationic and anionic starches and mixtures of the two. The adsorption kinetics on a polyester substrate was studied. The effect of charge and hydrophobicity on adsorption was investigated. Cationic starches were shown to readily adsorb on polyester and this was attributed to electrostatic interactions. Hydrophobic substituents on the cationic moiety resulted in increased adsorption. This was attributed to the weak hydrophobic interaction between the polymer chains which could result in a more coiled polymer conformation. It is hypothesized that more starch molecules are required for surface coverage of the polyester, resulting in an increase in adsorption. Anionic starch was adsorbed on the substrate but at a slower rate than the cationic starches. It is likely that there is a H bonding between acid groups on the starch and the ester groups of the polyester. However, the anionic starch is desorbed when the polyester is placed in an aqueous medium. When a blend of cationic starch and anionic starch was used, a low concentration of anionic starch was seen to increase adsorption, indicating that the polyelectrolyte complex itself may be adsorbing on the substrate. Further increases cause a decrease in adsorption as no sites may be available on the complex for adsorption. When hydrophobic substituents are present, addition of the anionic starch causes a decrease in adsorption at all concentrations. This was attributed to the "crosslinking" between the hydrophobically modified starch and the anionic polymer. Copyright 1999 Academic Press. PMID:10607442

  6. Hydrolysis of polyesters by lipases

    Microsoft Academic Search

    Yutaka Tokiwa; Tomoo Suzuki

    1977-01-01

    INCREASING public concern about the treatment of waste materials has stimulated the study of the biodegradation of synthetic polymers. Among synthetic polymers, aliphatic polyesters are generally known to be susceptible to biological attack1-5, but there are few reports of enzymes involved in their degradation. Bell et al.6 recently showed that the molecular weight of polycaprolactone (PCL) decreases on exposure to

  7. Jute-reinforced polyester composites

    Microsoft Academic Search

    P. J. Roe; M. P. Ansell

    1985-01-01

    Raw jute fibre has been incorporated in a polyester resin matrix to form uniaxially reinforced composites containing up to 60 vol% fibre. The tensile strength and Young's modulus, work of fracture determined by Charpy impact and inter-laminar shear strength have been measured as a function of fibre volume fraction. These properties all follow a Rule of Mixtures relationship with the

  8. Fabrication

    NASA Astrophysics Data System (ADS)

    Angel, Roger; Helms, Richard; Bilbro, Jim; Brown, Norman; Eng, Sverre; Hinman, Steve; Hull-Allen, Greg; Jacobs, Stephen; Keim, Robert; Ulmer, Melville

    1992-08-01

    What aspects of optical fabrication technology need to be developed so as to facilitate existing planned missions, or enable new ones? Throughout the submillimeter to UV wavelengths, the common goal is to push technology to the limits to make the largest possible apertures that are diffraction limited. At any one wavelength, the accuracy of the surface must be better than lambda/30 (rms error). The wavelength range is huge, covering four orders of magnitude from 1 mm to 100 nm. At the longer wavelengths, diffraction limited surfaces can be shaped with relatively crude techniques. The challenge in their fabrication is to make as large as possible a reflector, given the weight and volume constraints of the launch vehicle. The limited cargo diameter of the shuttle has led in the past to emphasis on deployable or erectable concepts such as the Large Deployable Reflector (LDR), which was studied by NASA for a submillimeter astrophysics mission. Replication techniques that can be used to produce light, low-cost reflecting panels are of great interest for this class of mission. At shorter wavelengths, in the optical and ultraviolet, optical fabrication will tax to the limit the most refined polishing methods. Methods of mechanical and thermal stabilization of the substrate will be severely stressed. In the thermal infrared, the need for large aperture is tempered by the even stronger need to control the telescope's thermal emission by cooled or cryogenic operation. Thus, the SIRTF mirror at 1 meter is not large and does not require unusually high accuracy, but the fabrication process must produce a mirror that is the right shape at a temperature of 4 K. Future large cooled mirrors will present more severe problems, especially if they must also be accurate enough to work at optical wavelengths. At the very shortest wavelengths accessible to reflecting optics, in the x-ray domain, the very low count fluxes of high energy photons place a premium on the collecting area. It is not necessary to reach or even approach the diffraction limit, which would demand subnanometer fabrication and figure control. Replication techniques that produce large very lightweight surfaces are of interest for x-ray optics just as they are for the submillimeter region. Optical fabrication requirements are examined in more detail for missions in each of the three spectral regions of interest in astrophysics.

  9. 75 FR 23300 - Greige Polyester/Cotton Printcloth From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    ...Third Review)] Greige Polyester/Cotton Printcloth From China AGENCY: United...antidumping duty order on greige polyester/cotton printcloth from China...antidumping duty order on greige polyester/cotton printcloth from China would be...

  10. Dielectric relaxations in aliphatic polyesters

    NASA Astrophysics Data System (ADS)

    Sen, Sudeepto

    2001-07-01

    The dielectric technique was used to study the relaxation processes of five linear aliphatic polyesters. The polyesters studied were poly (ethylene succinate/adipate) or PESA, poly (trimethylene succinate/adipate) or PTSA, poly (butylene succinate/adipate) or PBSA, poly (ethylene succinate) or PES, and poly (ethylene adipate) or PEA. Three of the polyesters were copolymers (PESA, PTSA, and PBSA), and the remaining two (PES and PEA) were homopolymers. Two of the five were amorphous (PESA and PTSA), and the remaining three (PBSA, PES, and PEA) were semicrystalline. All the five polyesters were synthesized in the laboratory using a poly-condensation reaction between a series of aliphatic diols and diesters. The succinic and adipic groups in the copolymers are in equimolar amounts. The polymers were characterized by differential scanning calorimetry and density measurements. Elemental analysis done on the polymers confirmed that their compositions matched theoretical estimates. The relaxation processes were studied dielectrically using an IMASS time domain dielectric spectrometer (TDS) and an HP 4284A LCR meter. Together they allowed a frequency range from 0.001 Hz to 1 MHz. Typically in the subglass region, good data were obtained between 0.01 Hz and 100 kHz. In the glass transition region, good data were occasionally available over the entire range. Two relaxation processes were detected in the subglass temperature region for all the polymers, and in the case of the copolymers PTSA and PBSA, they were also well resolved. Both the processes showed Arrhenius behavior with modest activation energies characteristic of subglass processes in general. They also progressively merged with increasing temperature, which implies a lower activation energy for the faster process which is consistent with the current understanding of relaxation phenomena. The glass transition region of all the polymers also showed a merging of the dominant alpha relaxation with the subglass processes which had appeared in this region in a coalesced form. This feature has previously been noted mostly in polymers with bulky side-groups.

  11. Fiber Reinforced Polyester Resins Polymerized by Microwave Source

    NASA Astrophysics Data System (ADS)

    Visco, A. M.; Calabrese, L.; Cianciafara, P.; Bonaccorsi, L.; Proverbio, E.

    2007-12-01

    Polyester resin based composite materials are widely used in the manufacture of fiberglass boats. Production time of fiberglass laminate components could be strongly reduced by using an intense energy source as well as microwaves. In this work a polyester resin was used with 2% by weight of catalyst and reinforced with chopped or woven glass fabric. Pure resin and composite samples were cured by microwaves exposition for different radiation times. A three point bending test was performed on all the cured samples by using an universal testing machine and the resulting fracture surfaces were observed by means of scanning electron microscopy (SEM). The results of mechanical and microscopy analyses evidenced that microwave activation lowers curing time of the composite while good mechanical properties were retained. Microwaves exposition time is crucial for mechanical performance of the composite. It was evidenced that short exposition times suffice for resin activation while long exposure times cause fast cross linking and premature matrix fracture. Furthermore high-radiation times induce bubbles growth or defects nucleation within the sample, decreasing composite performance. On the basis of such results microwave curing activation of polyester resin based composites could be proposed as a valid alternative method for faster processing of laminated materials employed for large-scale applications.

  12. Comfort and handle related properties of P\\/V blended air-jet textured yarn fabrics

    Microsoft Academic Search

    S. S. Mahish; S. K. Punj; V. K. Kothari

    2010-01-01

    The effect of blend percentage on comfort and handle related properties of fabrics made from polyester\\/viscose blended air-jet\\u000a textured yarn weft were studied and the results were compared with fabrics made from polyester\\/viscose ring-spun yarn wefts\\u000a of similar linear densities. It is observed that with increase in polyester content in the blend, the air permeability and\\u000a water vapour permeability reduces

  13. RHEOLOGY OF CONCENTRATED SOLUTIONS OF HYPERBRANCHED POLYESTERS

    EPA Science Inventory

    The solution rheology of different generations of hyperbranched polyesters in N-methyl-2- pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amido...

  14. Organic solvent absorption characteristics of split-type microfiber fabrics

    Microsoft Academic Search

    Kwang Ju Lee; Seong Hun Kim; Kyung Wha Oh

    2004-01-01

    Split-type nylon\\/polyester microfiber and polyester microfiber fabrics possess drapeability, softness, bulkiness, and smoothness,\\u000a so that they can be applied in various industrial fields. In particular, these fabrics are able to absorb various organic\\u000a solvents, and can be used as clean room materials. To investigate the chemical affinity between solvents and the compositional\\u000a materials of these fabrics, the contact angle of

  15. 21 CFR 177.1590 - Polyester elastomers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...List of substances Limitations 4,4? - Bis (alpha, alpha- dimethyl-benzyl) diphenylamine For use only as an antioxidant. Tetrabutyl titanate For use only as a catalyst. (c) An appropriate sample of the finished polyester...

  16. 21 CFR 177.1590 - Polyester elastomers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...List of substances Limitations 4,4? - Bis (alpha, alpha- dimethyl-benzyl) diphenylamine For use only as an antioxidant. Tetrabutyl titanate For use only as a catalyst. (c) An appropriate sample of the finished polyester...

  17. 21 CFR 177.1590 - Polyester elastomers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...List of substances Limitations 4,4? - Bis (alpha, alpha- dimethyl-benzyl) diphenylamine For use only as an antioxidant. Tetrabutyl titanate For use only as a catalyst. (c) An appropriate sample of the finished polyester...

  18. 21 CFR 177.1590 - Polyester elastomers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...List of substances Limitations 4,4? - Bis (alpha, alpha- dimethyl-benzyl) diphenylamine For use only as an antioxidant. Tetrabutyl titanate For use only as a catalyst. (c) An appropriate sample of the finished polyester...

  19. 21 CFR 177.1590 - Polyester elastomers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...List of substances Limitations 4,4? - Bis (alpha, alpha- dimethyl-benzyl) diphenylamine For use only as an antioxidant. Tetrabutyl titanate For use only as a catalyst. (c) An appropriate sample of the finished polyester...

  20. Integrated analysis of low profile unsaturated polyester and vinylester resins cured at low temperatures

    NASA Astrophysics Data System (ADS)

    Cao, Xia

    Unsaturated polyester and vinylester resins are used in a wide variety of applications. These materials provide high structural stability, increased resistance to solvent and temperature, and improved mechanical stability. Low profile additives have been found highly effective in eliminating the polymerization shrinkage of unsaturated polyester resins in high temperature molding processes such as compression molding of SMC and injection molding of BMC. In recent years, the improvement focuses on the development of low temperature and low-pressure fabrication techniques, such as low temperature/low pressure SMC, RTM, SCRIMP, to significantly reduce the tooling cost. However, poor performance of low profile additives and high residual reactivity in low temperature molding processes unavoidably undermine further applications of unsaturated polyester and vinylester resins. Therefore, there is considerable potential for improving the process through greater technical understanding of reaction and volume shrinkage control mechanism in low temperature cure of unsaturated polyester and vinylester resins. An integrated analysis is carried out in this study to investigate the reaction kinetics and shrinkage control of unsaturated polyester or vinylester resins with low profile additives cured at low temperatures. A differential scanning calorimeter (DSC), a Fourier transform infrared spectrometer (FTIR), and a rheometrics dynamic analyzer (RDA) are used to study the reaction kinetics and rheological behaviors. A dilatometer is applied to study the volume change. A scanning electron microscopy (SEM) and an optical microscopy are employed to investigate the structure and morphology evolution during curing. The effects of curing agents including initiator, promoter, and comonomer on the low temperature polymerization are investigated. These experiments are designed to provide information regarding the polymerization mechanism and microstructure evolution throughout the free radical polymerization. In addition, this information along with the relation between morphology and properties of crosslinked polymeric materials will be used to optimize polymerization conditions of unsaturated polyester and vinylester resins with desired properties for applications in composite matrix.

  1. Energy performance of fabric roofs

    SciTech Connect

    Beitin, K.I.

    1982-06-01

    The energy efficiency of fabric roofs is dependent on the thermal and optical characteristics of the fabric envelope. Vinyl coated polyester is used in temporary inflated ''bubbles''. Teflon coated fiberglass has been used in permanent structures such as the Pontiac Silverdome. Daylighting through the fabric is ample, but heat loss can be high in cold climates. The roof performs better in warm than in cold climates. The energy performance of the roof then depends on balancing gains from daylighting against heat loss. New fabrics utilizing daylighting with higher insulation values are being developed. Pneumatically operated fabric lenses for the new Denver Federal Office Building open and close to control heat loss, for example.

  2. 75 FR 42784 - Greige Polyester/Cotton Printcloth From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ...Investigation No. 731-TA-101 (Third Review)] Greige Polyester/Cotton Printcloth From China AGENCY: United States International Trade...revocation of the antidumping duty order on greige polyester/cotton printcloth from China would be likely to lead to...

  3. Synthetic polyester from algae oil.

    PubMed

    Roesle, Philipp; Stempfle, Florian; Hess, Sandra K; Zimmerer, Julia; Río Bártulos, Carolina; Lepetit, Bernard; Eckert, Angelika; Kroth, Peter G; Mecking, Stefan

    2014-06-23

    Current efforts to technically use microalgae focus on the generation of fuels with a molecular structure identical to crude oil based products. Here we suggest a different approach for the utilization of algae by translating the unique molecular structures of algae oil fatty acids into higher value chemical intermediates and materials. A crude extract from a microalga, the diatom Phaeodactylum tricornutum, was obtained as a multicomponent mixture containing amongst others unsaturated fatty acid (16:1, 18:1, and 20:5) phosphocholine triglycerides. Exposure of this crude algae oil to CO and methanol with the known catalyst precursor [{1,2-(tBu2 PCH2)2C6H4}Pd(OTf)](OTf) resulted in isomerization/methoxycarbonylation of the unsaturated fatty acids into a mixture of linear 1,17- and 1,19-diesters in high purity (>99?%). Polycondensation with a mixture of the corresponding diols yielded a novel mixed polyester-17/19.17/19 with an advantageously high melting and crystallization temperature. PMID:24845347

  4. Microbial Odor Profile of Polyester and Cotton Clothes after a Fitness Session

    PubMed Central

    Callewaert, Chris; De Maeseneire, Evelyn; Kerckhof, Frederiek-Maarten; Verliefde, Arne; Van de Wiele, Tom

    2014-01-01

    Clothing textiles protect our human body against external factors. These textiles are not sterile and can harbor high bacterial counts as sweat and bacteria are transmitted from the skin. We investigated the microbial growth and odor development in cotton and synthetic clothing fabrics. T-shirts were collected from 26 healthy individuals after an intensive bicycle spinning session and incubated for 28 h before analysis. A trained odor panel determined significant differences between polyester versus cotton fabrics for the hedonic value, the intensity, and five qualitative odor characteristics. The polyester T-shirts smelled significantly less pleasant and more intense, compared to the cotton T-shirts. A dissimilar bacterial growth was found in cotton versus synthetic clothing textiles. Micrococci were isolated in almost all synthetic shirts and were detected almost solely on synthetic shirts by means of denaturing gradient gel electrophoresis fingerprinting. A selective enrichment of micrococci in an in vitro growth experiment confirmed the presence of these species on polyester. Staphylococci were abundant on both cotton and synthetic fabrics. Corynebacteria were not enriched on any textile type. This research found that the composition of clothing fibers promotes differential growth of textile microbes and, as such, determines possible malodor generation. PMID:25128346

  5. Microbial odor profile of polyester and cotton clothes after a fitness session.

    PubMed

    Callewaert, Chris; De Maeseneire, Evelyn; Kerckhof, Frederiek-Maarten; Verliefde, Arne; Van de Wiele, Tom; Boon, Nico

    2014-11-01

    Clothing textiles protect our human body against external factors. These textiles are not sterile and can harbor high bacterial counts as sweat and bacteria are transmitted from the skin. We investigated the microbial growth and odor development in cotton and synthetic clothing fabrics. T-shirts were collected from 26 healthy individuals after an intensive bicycle spinning session and incubated for 28 h before analysis. A trained odor panel determined significant differences between polyester versus cotton fabrics for the hedonic value, the intensity, and five qualitative odor characteristics. The polyester T-shirts smelled significantly less pleasant and more intense, compared to the cotton T-shirts. A dissimilar bacterial growth was found in cotton versus synthetic clothing textiles. Micrococci were isolated in almost all synthetic shirts and were detected almost solely on synthetic shirts by means of denaturing gradient gel electrophoresis fingerprinting. A selective enrichment of micrococci in an in vitro growth experiment confirmed the presence of these species on polyester. Staphylococci were abundant on both cotton and synthetic fabrics. Corynebacteria were not enriched on any textile type. This research found that the composition of clothing fibers promotes differential growth of textile microbes and, as such, determines possible malodor generation. PMID:25128346

  6. Effect of polyester backbone structure on the cured products properties

    Microsoft Academic Search

    S. Y Tawfik; J. N Asaad; M. W Sabaa

    2003-01-01

    A new monomer (o-carboxy phthalanilic acid) was prepared by the reaction of o-aminobenzoic acid with phthalic anhydride. This monomer was condensed with different acids and glycols to prepare three unsaturated polyester resins namely, poly (1,2-propylene-maleate-o-carboxy phthalanilate) polyester I, poly (ethylene- maleate- o-carboxy phthalanilate) polyester II and poly (1,2-propylene-itaconate- o-carboxy phthalanilate) polyester III. Infrared (IR) and nuclear magnetic resonance (NMR) spectra

  7. Microbial production of lactate-containing polyesters

    PubMed Central

    Yang, Jung Eun; Choi, So Young; Shin, Jae Ho; Park, Si Jae; Lee, Sang Yup

    2013-01-01

    Due to our increasing concerns on environmental problems and limited fossil resources, biobased production of chemicals and materials through biorefinery has been attracting much attention. Optimization of the metabolic performance of microorganisms, the key biocatalysts for the efficient production of the desired target bioproducts, has been achieved by metabolic engineering. Metabolic engineering allowed more efficient production of polyhydroxyalkanoates, a family of microbial polyesters. More recently, non-natural polyesters containing lactate as a monomer have also been produced by one-step fermentation of engineered bacteria. Systems metabolic engineering integrating traditional metabolic engineering with systems biology, synthetic biology, protein/enzyme engineering through directed evolution and structural design, and evolutionary engineering, enabled microorganisms to efficiently produce natural and non-natural products. Here, we review the strategies for the metabolic engineering of microorganisms for the in vivo biosynthesis of lactate-containing polyesters and for the optimization of whole cell metabolism to efficiently produce lactate-containing polyesters. Also, major problems to be solved to further enhance the production of lactate-containing polyesters are discussed. PMID:23718266

  8. Investigation on Physico-Mechanical Properties, Water, Thermal and Chemical Ageing of Unsaturated Polyester\\/Turmeric Spent Composites

    Microsoft Academic Search

    Murtuza Ali Syed; Siddaramaiah; Raihan Taqui Syed; Akheel Ahmed Syed

    2010-01-01

    Nutraceutical industrial residues are potential fillers to fabricate green or eco-friendly polymeric composite materials as they are, less costly and easily available. Attempts have been made to use turmeric spent (TS)—a nutraceutical industry waste with a high E-factor to improve need-based properties of plastics. A series of unsaturated polyester resin composites have been fabricated with different turmeric spent content viz.,

  9. Cyclic fatigue and wear in deepwater polyester mooring systems

    Microsoft Academic Search

    Ray R. Ayers; Saltuk B. Aksu

    2009-01-01

    Fatigue life of deepwater mooring lines is a very important issue in the design of mooring systems for offshore structures. Polyester ropes experience cyclic loading over the life of the mooring, and the remaining strength of those ropes is reduced over time as individual fibers comprising the rope are broken. Fatigue and wear testing of polyester fibers and polyester subropes

  10. Engineering bacteria to manufacture functionalized polyester beads

    PubMed Central

    Draper, Jenny L.; Rehm, Bernd H.

    2012-01-01

    The ability to generate tailor-made, functionalized polyester (polyhydroxyalkanoate, PHA) beads in bacteria by harnessing their natural carbon-storage granule production system is an exciting recent development. Proteins that naturally attach to the polyester granule core were rationally engineered to enable in vivo production of PHA beads which are applicable in bioseparation, protein purification, enzyme immobilization and diagnostics and which show advantageous properties toward the development of safe and efficient particulate vaccines. These beads are recombinantly produced as fully functional, insoluble polyester inclusions that can be easily separated from the cell. This simple one-step production of functionalized beads provides a tantalizing alternative to current commercial functional beads, for which proteins must be expressed, purified and then chemically attached to solid supports. The recent success in generating antigen-displaying PHA granules in the food-grade bacterium Lactococcus lactis capable of mediating protective immunity against Mycobacterium tuberculosis infection highlights the promise and flexibility of this new technology. PMID:22705844

  11. Recovery and Reuse of Waste PVC Coated Fabrics. Part 1: Experimental Procedures and Separation of Fabric Components

    Microsoft Academic Search

    Sabit Adanur; Zhenwei Hou; Royall M. Broughton

    1998-01-01

    The polyester in the base fabrics (PET) and the polyvinyl chloride coating (PVC) along with plasticizers and adhesive\\/glue were separated from a commercial coated fabric by a scheme of chopping, grinding, and extracting with a selected preferred aqueous MEK solution. A novel recovering method called swelling method is introduced to separate and reuse waste PVC coated PET fabrics. In comparison

  12. UV curable hard coatings on polyesters

    NASA Astrophysics Data System (ADS)

    Datashvili, Tea; Brostow, Witold; Kao, David

    2006-10-01

    UV curable, hard and transparent hybrid inorganic-organic coatings with covalent links between the inorganic and the organic networks were prepared using organically crosslinked heteropolysiloxanes based on the sol-gel process. The materials were applied onto polyester sheets and UV cured. The deposition was followed by a thermal treatment to improve mechanical properties of the coatings. High light transmission and the resulting thermophysical properties indicate the presence of a nanoscale hybrid composition. The coatings show excellent adhesion to polyesters even without using primers. Further mechanical characterization shows that the coatings provide high hardness and good abrasion resistance.

  13. Review of Polyester Polymer Concrete Properties

    Microsoft Academic Search

    Victor Y. Garas; C. Vipulanandan

    Polymer Concrete (PC) composites posses a unique combination of properties that depend upon the formulation. This study reviewed the variations in polyester polymer concrete mixture components that affected the properties. The effect of resin content, aggregates, fibers and coupling agents were critically reviewed. It was found that the optimum polymer content varied from 12% to 14% (w\\/w). Using fibers and

  14. Impregnated polyester arterial prostheses: performance and prospects.

    PubMed

    Chakfé, N; Bizonne, S C; Beaufigeau, M; Urban, E; Cardon, A; Doillon, C; Le Magnen, J F; Durand, B; Kretz, J G

    1999-09-01

    Impregnated polyester arterial prostheses have gained wide acceptance by most vascular surgery teams, probably because these prostheses are easy to use, without any preclotting. We offer here a synthesis of the main studies that have appraised the experimental and clinical performance of these prostheses, and we delineate their major prospects. PMID:10466995

  15. Thermal and physical characterization of glycerol polyesters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glycerol polyesters were prepared by the condensation of glycerol and adipic acid, azelaic acid, sebacic acid, or suberic acids. After 48 hours at 125 deg C the polymers were clear and flexible. Samples of the reaction mixtures were analyzed by modulated differential scanning calorimetry to identi...

  16. Bio-based liquid crystalline polyesters

    NASA Astrophysics Data System (ADS)

    Wilsens, Carolus; Rastogi, Sanjay; Dutch Collaboration

    2013-03-01

    The reported thin-film polymerization has been used as a screening method in order to find bio-based liquid crystalline polyesters with convenient melting temperatures for melt-processing purposes. An in depth study of the structural, morphological and chemical changes occurring during the ongoing polycondensation reactions of these polymers have been performed. Structural and conformational changes during polymerization for different compositions have been followed by time resolved X-ray and Infrared spectroscopy. In this study, bio-based monomers such as vanillic acid and 2,5-furandicarboxylic acid are successfully incorporated in liquid crystalline polyesters and it is shown that bio-based liquid crystalline polymers with high aromatic content and convenient processing temperatures can be synthesized. The reported thin-film polymerization has been used as a screening method in order to find bio-based liquid crystalline polyesters with convenient melting temperatures for melt-processing purposes. An in depth study of the structural, morphological and chemical changes occurring during the ongoing polycondensation reactions of these polymers have been performed. Structural and conformational changes during polymerization for different compositions have been followed by time resolved X-ray and Infrared spectroscopy. In this study, bio-based monomers such as vanillic acid and 2,5-furandicarboxylic acid are successfully incorporated in liquid crystalline polyesters and it is shown that bio-based liquid crystalline polymers with high aromatic content and convenient processing temperatures can be synthesized. Special thanks to the Dutch Polymer Institute for financial support

  17. Electromagnetic interference shielding effectiveness of electroless Cu-plated PET fabrics

    Microsoft Academic Search

    Eun Gyeong Han; Eun Ae Kim; Kyung Wha Oh

    2001-01-01

    In order to develop the high quality electromagnetic interference (EMI) shielding textiles for protective clothing, polyester fabrics were electroless copper-plated. Effects of pretreatment conditions such as scouring, etching, and catalyzation on electromagnetic interference shielding effectiveness (EMISE) and physical properties of treated fabrics were investigated.High EMISE of fabrics over the wide range of frequency level were obtained when fabrics were scoured

  18. Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

    NASA Astrophysics Data System (ADS)

    Poillucci, Richard

    Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an automated fiber placement machine and the successful fabrication of a carbon fiber plate with an integrated microvascular channel is demonstrated.

  19. High performance polyester concrete using recycled PET

    SciTech Connect

    Rebeiz, K.S. [Lafayette Coll., Easton, PA (United States). Dept. of Civil and Environmental Engineering

    1995-10-01

    Recycled polyethylene terephthalate (PET) plastic wastes could be used in production of unsaturated polyester resins. In turn, these resins could be mixed with inorganic aggregates to produce polymer concrete (PC). Unsaturated polyesters based on recycled PET might be a potentially lower source cost of resins for producing useful PC based-products. The advantage of recycling PET in PC is that the PET materials do not have to be purified, including removal of colors, to the same extent as other PET recycling applications, which should facilitate the recycling operation and minimize its cost. The recycling of PET in PC could also help save energy and allow the long term disposal of the PET waste, an important advantage in recycling applications.

  20. Hexaferrite/Polyester Composite Coatings for Electromagnetic-Wave Absorbers

    NASA Astrophysics Data System (ADS)

    Lisjak, Darja; Bégard, Marion; Bruehl, Markus; Bobzin, Kirsten; Hujanen, Arto; Lintunen, Pertti; Bolelli, Giovanni; Lusvarghi, Luca; Ovtar, Simona; Drofenik, Miha

    2011-03-01

    Composite coatings, consisting of a ceramic barium hexaferrite and polyester, were manufactured by atmospheric plasma spraying. The crystalline structure of the barium hexaferrite was preserved during the spraying process while the polyester first (partly) melted and then resolidified. The high magnetic losses of the barium hexaferrite at mm-waves were coupled to the dielectric losses of the polyester in the composite coating and the superior electromagnetic absorption of the composite coating with respect to the pure materials was determined.

  1. Mechanical properties of polyester polymer-concrete

    Microsoft Academic Search

    R. D. Maksimov; L. Jirgens; J. Jansons; E. Plume

    1999-01-01

    The properties of a polymer-concrete composed of polyester matrix and locally available rock aggregate are investigated. The\\u000a formula of the concrete is found by an experimental-calculation approach in such a way as to attain a closer packing of the\\u000a aggregate particles on the one hand, and to ensure the needed processing characteristics (placeability) of the mix on the\\u000a other. It

  2. Aromatizing unzipping polyester for EUV photoresist

    NASA Astrophysics Data System (ADS)

    Matsuzawa, Kensuke; Mesch, Ryan; Olah, Mike; Wang, Wade; Phillips, Scott T.; Willson, C. Grant

    2015-03-01

    New "self-immolating" or "unzipping" polymers, materials that depolymerize in response to irradiation, were designed and prepared successfully. We studied several candidate polymers and ultimately chose two of them for further development. One is a polyester that aromatizes upon depolymerization. The unzipping reaction initiated by UV exposure in solution was confirmed. The polymer was then studied in thin films to assess its potential for use in formulating photoresists. The neat polymer was tested as a blend with novolac resin. The effect of unzipping polyester loading in novolac on the rate of dissolution of films in TMAH was studied. Inhibition occurs at 20-30% loading. The films were exposed with DUV light and patterning was observed. The sensitivity of the unzipping polyester formulation is low in part due to the low absorption of the polymer for UV light. However, the polymer showed higher sensitivity with EUV exposure and first contrast curves show sensitivity in the range of 20-25mJ/cm2.

  3. Finite element description of nonlinear viscoelastic behaviour of technical fabric

    Microsoft Academic Search

    Pawe? K?osowski; Wies?aw Komar; Krzysztof Wo?nica

    2009-01-01

    The proposal of the nonlinear viscoelastic behaviour description of textile material is presented in this work. The considered fabric is made of two polyester thread families woven perpendicularly to each other with double side PVC coating. The long-term uniaxial creep laboratory tests in the threads direction were conducted at five different constant stress levels. For the fabric behaviour characterization the

  4. Recovery and Reuse of Waste PVC Coated Fabrics. Part 1: Experimental Procedures and Separation of Fabric Components

    Microsoft Academic Search

    Sabit Adanur; Zhenwei Hou; Royall M. Broughton

    1998-01-01

    The polyester in the base fabrics (PET) and the polyvinyl chloride coating (PVC) along with plasticizers and adhesive\\/glue were separated from a commercial coated fabric by a scheme of chopping, grinding, and extracting with a selected preferred aqueous MEK solution. A novel recovering method called swelling method is introduced to separate and reuse waste PVC coated PET fab rics. In

  5. Interfacial shear strength and thermal properties of electron beam-treated henequen fibers reinforced unsaturated polyester composites

    Microsoft Academic Search

    Yansong Pang; Donghwan Cho; Seong Ok Han; Won Ho Park

    2005-01-01

    Natural fiber henequen\\/unsaturated polyester (UPE) composites were fabricated by means of a compression molding technique\\u000a using chopped henequen fibers treated at various electron beam (EB) dosages. The interfacial shear strength (IFSS), dynamic\\u000a mechanical properties, and thermal expansion behavior were investigated through a single fiber microbonding test, fractographic\\u000a observation, dynamic mechanical analysis, and thermomechanical analysis, respectively. The results indicated that the

  6. Influence of Carbon Nano Tubes on the Thermo-Mechanical Properties of Unsaturated Polyester Nanocomposite

    NASA Astrophysics Data System (ADS)

    Moshiul Alam, A. K. M.; Beg, M. D. H.; Mohd Yunus, Rosli

    2015-04-01

    To date nano fillers are renowned reinforcing agent for polymer materials. In this work, unsaturated polyester (UPR) nanocomposites were fabricated by 0.1, 0.3 and 0.5 wt% multi walled carbon nanotubes (MWCNTs) through solution dispersion and casting method. The influence of MWCNT content was investigated by thermo-mechanical properties. Dispersion of nanotubes was observed by fracture morphology. The strength of nanocomposites rose with raising the CNT content. Moreover, DSC thermograms of nanocomposites represent noticeable improvement of glass transition temperature (Tg), melting temperature (Tm) and enthalpy (?Hm). Micro-crystallinity of nanocomposites increased with increasing the CNT content. Moreover, the stiffness increased with increasing the CNT content.

  7. Durability of Polyester Ropes Used as Deepwater Mooring Lines

    Microsoft Academic Search

    J. Flory; S. J. Banfield

    2006-01-01

    Four failure modes have concerned others as potentially limiting the service life of polyester ropes used as deepwater mooring lines: axial compression fatigue, creep rupture, hysteresis heating, and internal abrasion. Based on extensive investigations and testing, the first three modes are of no concern with polyester rope. Internal abrasion is the only failure mode of possible concern. It is not

  8. Thermally Active Fabrics Containing Polyethylene Glycols

    Microsoft Academic Search

    Joseph S. Bruno; Tyrone L. Vigo

    1987-01-01

    Polyethylene glycols (PEG) of low molecular weight (300-1,000) can be durably bound to cotton, cotton-polyester blends, and most commercially available fabrics (such as wool, acrylic and nylon) by a pad-dry-cure method utilizing a polyfunc tional crosslinking agent. The extent to which the PEGs react with and are bonded to the fabrics is dependent on the molecular weight of the polymer,

  9. Incorporation of radioactive wastes into styrenated polyester

    SciTech Connect

    Ikladious, N.E.; Ghattas, N.K.; Eskander, S.B.

    1986-01-01

    Styrenated polyester (poly(oxydiethylene maleate)) is examined as a medium for immobilization of simulated spent-ion exchange resin used at Inshas Reactor (Egypt). Compressive strength and hardness values illustrated the stability of the final products towards radiation. TG, DTG, and DTA diagrams showed the thermal instability of the final waste form at about 375/sup 0/C. Leaching experiment on incorporated blocks of active resin labelled with /sup 137/Cs, /sup 144/Ce, and /sup 106/Ru showed that the cumulative leaching rate for Ce is lower than those for Ru and Cs.

  10. Reactive modification of polyesters and their blends

    NASA Astrophysics Data System (ADS)

    Wan, Chen

    2004-12-01

    As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring the desired rheological and structural characteristics of the final products for potential applications such as low density extrusion foaming or compatibilization of immiscible polymer blends. Important modification conditions through coagents are identified and reaction mechanisms are proposed. A high MW saturated polyester, PET, can also be rheologically modified in extruders through low MW multifunctional anhydride and epoxy compounds by chain extension/branching. Several such modifiers were successfully screened in terms of their reactivity towards PET under controlled reactive extrusion conditions. A dianhydride with medium reactivity was then successfully used in a one-step reactive modification/extrusion foaming process to produce low density foams. A similar process was successfully used to produce small cell size foams from a four component system containing PET, PP and lesser amounts of a low molecular weight multifunctional epoxy compound and an acid functionalized polyolefin, the latter acting as compatibilizers.

  11. Disposable polyester-toner electrophoresis microchips for DNA analysis.

    PubMed

    Duarte, Gabriela R M; Coltro, Wendell K T; Borba, Juliane C; Price, Carol W; Landers, James P; Carrilho, Emanuel

    2012-06-01

    Microchip electrophoresis has become a powerful tool for DNA separation, offering all of the advantages typically associated with miniaturized techniques: high speed, high resolution, ease of automation, and great versatility for both routine and research applications. Various substrate materials have been used to produce microchips for DNA separations, including conventional (glass, silicon, and quartz) and alternative (polymers) platforms. In this study, we perform DNA separation in a simple and low-cost polyester-toner (PeT)-based electrophoresis microchip. PeT devices were fabricated by a direct-printing process using a 600 dpi-resolution laser printer. DNA separations were performed on PeT chip with channels filled with polymer solutions (0.5% m/v hydroxyethylcellulose or hydroxypropylcellulose) at electric fields ranging from 100 to 300 V cm(-1). Separation of DNA fragments between 100 and 1000 bp, with good correlation of the size of DNA fragments and mobility, was achieved in this system. Although the mobility increased with increasing electric field, separations showed the same profile regardless of the electric field. The system provided good separation efficiency (215,000 plates per m for the 500 bp fragment) and the separation was completed in 4 min for 1000 bp fragment ladder. The cost of a given chip is approximately $0.15 and it takes less than 10 minutes to prepare a single device. PMID:22545263

  12. Micro-thermal analysis of polyester coatings

    NASA Astrophysics Data System (ADS)

    Fischer, Hartmut R.

    2010-04-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure like chain scission and cross-linking are manifested by a shift of the LTA detectable Tg and by a change of the slope of the part of the LTA graph responsible for the penetration of the hot sensor into the material after passing the glass transition temperature. As such LTA is a valuable tool to have a quick look into coating surfaces and especially their ageing. The photo-degradation of polyester in air leads to the formation of a cross-linked network at a surface layer of about 3-4 ?m coupled with an increase in hardness and of the glass transition temperature by ˜90 K, the effect is less drastic for a photo-degradation in a nitrogen environment. Moreover, the presence of a non-equilibrium dense surface layer with a higher Tg formed during the drying of the coating formulation and the film solidification can be shown.

  13. Mechanical- and oil-durable superhydrophobic polyester materials for selective oil absorption and oil/water separation.

    PubMed

    Wu, Lei; Zhang, Junping; Li, Bucheng; Wang, Aiqin

    2014-01-01

    The low stability and complicated fabrication procedures seriously hindered practical applications of superhydrophobic materials. Here we present a facile approach for preparing durable superhydrophobic polyester materials by dip-coating in a nanocomposite solution of polymerized tetraethoxysilane and n-hexadecyltriethoxysilane. The coated samples exhibit excellent superhydrophobicity, superoleophilicity, mechanical and chemical stabilities. This is attributed to the tight binding of the nanocomposite on the polyester fibers and the inherent stability of silicone. The coated samples can quickly absorb petrol, diesel and crude oil, and show very high selectivity in oil/water separation. In addition, the coated samples could maintain their superhydrophobicity, oil absorption capacity and oil/water selectivity after harsh mechanical damage, 90 days of immersion in oils and ten cycles of absorption-desorption. Moreover, this approach is simple and can be easily scaled up for producing samples on a large size, which makes it very promising for practical oil absorption. PMID:24183438

  14. Development of molded, coated fabric joints: Fabric construction criteria for a spacesuit elbow joint

    NASA Technical Reports Server (NTRS)

    Olson, L. H.

    1981-01-01

    The design and fabrication of a molded, coated fabric elbow joint capable of operating reliably at 8 psi internal pressure for extended periods of flexure is considered. The overall design of the joint includes: (1) selection of heatsettable fiber of sufficient strengths; (2) choosing an optimum fabric construction; (3) a fatigue resistant; flexible coating; and (4) a molding technique. A polyester yarn of type 56 Dacron and a urethane coating system were selected. The relationships between yarn and weave parameters which lead to an optimum fabric construction for the 8 psi elbow joint are defined.

  15. 21 CFR 177.2420 - Polyester resins, cross-linked.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...of this section 6. Miscellaneous materials: Castor oil, hydrogenated ?-Methylstyrene Polyethylene glycol 6000 Silicon dioxide Wax, petroleum Complying with § 178.3710 of this chapter. (c) The cross-linked polyester...

  16. A biomedical library of serinol-derived polyesters.

    PubMed

    Rickerby, Jenny; Prabhakar, Roopa; Patel, Anita; Knowles, Jonathan; Brocchini, Steve

    2005-01-01

    Polyesters derived from glycerol and serinol were prepared. These polyesters were designed to be potential surrogate polymers for poly(glycolic acid) (PGA) to extend the properties that aliphatic biomedical polyesters could encompass. The 1- and 2-substituted glycerol derived monomers were liquids and difficult to polymerize reproducibly. In contrast the N-substituted serinol monomers were solids and easy to prepare. Each of the four N-substituted serinol-diol monomers was polymerized in a parallel fashion with each of the four commercially available diacids to produce a small library of 16 polyesters. Glass transition and contact angle values were determined to ascertain structure-property correlations due to defined chemical changes in the polymer mainchain and pendent chain. A serinol-derived precursor polymer was also prepared. PMID:15588891

  17. Degradation kinetics of glass-reinforced polyesters in chemical environments

    Microsoft Academic Search

    S. P. Sonawala; R. J. Spontak

    1996-01-01

    Glass-reinforced polyesters (GRPs) are attractive in structural applications due to their strength-to-weight ratio and resistance to chemical attack. For marine and processing applications, in particular, GRPs must withstand long-term exposure to brine and either highly acidic or basic aqueous solutions. In this work, we report on the degradation of two GRP laminates, a pultruded isophthalic polyester (IPE) and a hand-moulded

  18. Synthesis and thermal properties of polyesters from cyclotriphosphazene

    Microsoft Academic Search

    K. Miyata; K. Muraoka; T. Itaya; T. Tanigaki; K. Inoue

    1996-01-01

    Polyesters containing cyclotriphosphazene units have been prepared by phase transfer catalyzed two-phase polycondensation and direct polycondensation. The polycondensation of the acid chloride of (trans-2,4-dicarboxyphenoxy-2,4,6,6-tetraphenoxy)cyclotriphosphazene (trans-CPP) and bisphenol A (BA) in the presence of benzyltriethylammonium chloride (BTEAC) as phase transfer reagent gave a polyester with a molecular weight of 22,000, whereas only oligomer was obtained by the polycondensation of the cis-isomer

  19. Hydrolyzable polyester resins, varnishes and coating compositions containing the same

    DOEpatents

    Yamamori, Naoki (Minoo, JP); Yokoi, Junji (Nara, JP); Yoshikawa, Motoyoshi (Nara, JP)

    1984-01-01

    Preparation of hydrolyzable polyester resin comprising reacting polycarboxylic acid and polyhydric alcohol components, which is characterized by using, as at least part of said polyhydric alcohol component, a metallic salt of hydroxy carboxylic acid of the formula defined and effecting the polycondensation at a temperature which is no more than the decomposition temperature of said metallic salt. The polyester resins are useful as resinous vehicle of varnishes and antifouling paints.

  20. Crease recovery, mechanical and thermal properties of synthetic fabrics treated with electron beam irradiation

    Microsoft Academic Search

    M. H. Zohdy; S. S. Mohamed; Abdel Wahab M. El-Naggar

    2004-01-01

    The effect of surface treatment of polyester, nylon-6 and cotton\\/polyester fabrics, with formulations based on polydimethylsiloxane (PDMS) followed by electron beam irradiation, on the crease recovery, mechanical and thermal properties was investigated. The non-reactive siloxane was activated with styrene (S) or methyl methacrylate (MMA) monomers and their corresponding oligomers. The crease recovery properties were determined in terms of the recovery

  1. 75 FR 38463 - Greige Polyester Cotton Printcloth From the People's Republic of China: Final Results of Sunset...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ...Administration [A-570-101] Greige Polyester Cotton Printcloth From the People's Republic...antidumping duty order on greige polyester cotton printcloth from the People's Republic...antidumping duty order on greige polyester cotton printcloth from the PRC. See Greige...

  2. Steady-state thermal comfort properties of fabrics incorporated with microencapsulated phase change materials

    Microsoft Academic Search

    Sennur Alay; Cemil Alkan; Fethiye Göde

    2012-01-01

    This study focused on assessing the thermal comfort properties of the fabrics incorporating microencapsulated phase change materials (microPCMs) under steady-state condition. Air permeability and water vapor permeability of the fabrics were also investigated. Poly(methyl methacrylate)\\/n-hexadecane microcapsules were applied to the cotton and cotton\\/polyester fabrics using pad-cure methods. Thermal comfort properties of the fabrics were measured using Alambeta. The results indicated

  3. Steady-state thermal comfort properties of fabrics incorporated with microencapsulated phase change materials

    Microsoft Academic Search

    Sennur Alay; Cemil Alkan; Fethiye Göde

    2011-01-01

    This study focused on assessing the thermal comfort properties of the fabrics incorporating microencapsulated phase change materials (microPCMs) under steady-state condition. Air permeability and water vapor permeability of the fabrics were also investigated. Poly(methyl methacrylate)\\/n-hexadecane microcapsules were applied to the cotton and cotton\\/polyester fabrics using pad-cure methods. Thermal comfort properties of the fabrics were measured using Alambeta. The results indicated

  4. Thermo-physiological comfort of a PES fabric with incorporated activated carbon : Part II: wear trials

    Microsoft Academic Search

    R. Splendore; F. Dotti; B. Cravello; A. Ferri

    2011-01-01

    Purpose – The purpose of this paper is to consider the thermal-physiological comfort performances of a sport shirt made of a polyester (PES) fabric with incorporated activated carbon. After having characterized the modified PES fabric in Part I, the results of a wear trial campaign are shown and discussed in this work. Design\\/methodology\\/approach – The wear trials have been carried

  5. Fabrication and dynamic mechanical behavior of nanocomposites

    Microsoft Academic Search

    Victor Manuel Fortes Evora

    2004-01-01

    Polyester\\/TiO2 nanocomposites have been fabricated using an in-situ polymerization technique coupled with ultrasonics, and an investigation has been conducted to characterize their mechanical and fracture behavior under quasi-static and dynamic loading conditions. The presence of the particles had the greatest effect on fracture toughness; negligible particle influence was observed in the remaining mechanical properties obtained using quasi-static loading. Scanning electron

  6. Characterization of Polyester Properties by Molecular Simulations Caibao Qian, Tahir Cagin and Zhuo Min Chen

    E-print Network

    Goddard III, William A.

    Characterization of Polyester Properties by Molecular Simulations Techniques Caibao Qian, Tahir Avenue, Suite 540, Pasadena, CA 91101, USA Introduction We present a study of various physical properties of the polyesters: polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene isophthalate

  7. SOLUTION RHEOLOGY OF HYPERBRANCHED POLYESTERS AND THEIR BLENDS WITH LINEAR POLYMERS

    EPA Science Inventory

    In this study, the rheological properties of different generations of hyperbranched polyesters in 1-methyl-2-pyrrolidinone solvent and their blends with poly(2-hydroxyethyl methacrylate) have ben investigated. All the hyperbranched polyester solutions exhibited Newtonian behavior...

  8. 40 CFR 721.10574 - Alkylcarboxy polyester acrylate reaction products with mixed metal oxides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...New Uses for Specific Chemical Substances § 721...Alkylcarboxy polyester acrylate reaction products with mixed...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...alkylcarboxy polyester acrylate reaction products with...

  9. 40 CFR 721.10574 - Alkylcarboxy polyester acrylate reaction products with mixed metal oxides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...New Uses for Specific Chemical Substances § 721...Alkylcarboxy polyester acrylate reaction products with mixed...generic). (a) Chemical substance and significant...reporting. (1) The chemical substance identified...alkylcarboxy polyester acrylate reaction products with...

  10. Photoresponsive polyesters by incorporation of alkoxyphenacyl or coumarin chromophores along the backbone.

    PubMed

    Chamsaz, Elaheh A; Sun, Shuangyi; Maddipatla, Murthy V S N; Joy, Abraham

    2014-02-01

    The synthesis and photochemical characterization of two classes of photoresponsive polyesters are described. These polyesters contain either alkoxyphenacyl or coumarin chromophores embedded along the polymer chain. The alkoxyphenacyl polyesters undergo efficient photoinduced chain scission upon irradiation at 300 nm in solution or as a nanoparticle suspension. At 254 nm the coumarin polyesters undergo polymer chain scission. Irradiation of the coumarin polyesters in solution at 350 nm results in both chain crosslinking and chain scission behavior, while irradiation of the coumarin polyesters as nanoparticles results in chain crosslinking. The properties of the alkoxyphenacyl and coumarin polyesters are influenced by the choice of diacid as seen from their thermal behavior. The use of glutamic acid enabled surface or bulk functionalization of the photoresponsive polymers. In addition, controlled release of Nile Red from coumarin polyester nanoparticles is demonstrated by modulation of the wavelength and intensity of irradiation. PMID:24407420

  11. Biodegradation of Polyester Polyurethane by Endophytic Fungi?

    PubMed Central

    Russell, Jonathan R.; Huang, Jeffrey; Anand, Pria; Kucera, Kaury; Sandoval, Amanda G.; Dantzler, Kathleen W.; Hickman, DaShawn; Jee, Justin; Kimovec, Farrah M.; Koppstein, David; Marks, Daniel H.; Mittermiller, Paul A.; Núñez, Salvador Joel; Santiago, Marina; Townes, Maria A.; Vishnevetsky, Michael; Williams, Neely E.; Vargas, Mario Percy Núñez; Boulanger, Lori-Ann; Bascom-Slack, Carol; Strobel, Scott A.

    2011-01-01

    Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation. PMID:21764951

  12. Synthesis and characterization of telechelic phosphine oxide polyesters and cobalt(II) chloride complexes

    Microsoft Academic Search

    Qin Lin; Serkan Unal; Ann R. Fornof; R. Scott Armentrout; Timothy E. Long

    2006-01-01

    A monofunctional phosphine oxide containing endcapping reagent, 4-carboxyphenyl biphenyl phosphine oxide, was synthesized for the preparation of telechelic polyester oligomers. The chemical structure of the endcapping reagent was verified using NMR spectroscopy, mass spectroscopy, and elemental analysis. Phosphine oxide telechelic polyesters were prepared for the first time via copolymerization of a low molar mass polyester oligomer precursor and the phosphine

  13. EFFECT OF VARIOUS FORMS OF GLASS FIBER REINFORCEMENTS ON TENSILE PROPERTIES OF POLYESTER MATRIX COMPOSITE

    Microsoft Academic Search

    Gul Hameed Awan; Liaqat Ali

    2009-01-01

    Unsaturated polyesters are important matrix resins used for glass fiber reinforced composites\\/plastics. The strength of fiber glass reinforced polyester composite is mainly related to the glass content of the material and the arrangement of glass fibers. In general, the higher the weight percent glass in the composites, the stronger is the reinforced composite. Polyester matrix composites (PMC) have good specific

  14. The Effect of Inorganic Fillers on the Mechanical and Thermal Properties of Polyester

    Microsoft Academic Search

    Hosam E. H. Seleem

    2006-01-01

    Polyester resins are the most widely used resin systems. Filler materials are used extensively with polyester resin for a variety of reasons, such as cost reduction, and more importantly, to enhance some physical and\\/or mechanical properties. Through the present work several types of inorganic fillers (cement, silica fume, and sand) were incorporated into the polyester resin. Their effects on the

  15. DEVELOPMENT AND CHARACTERIZATION OF VINYL ESTER OLIGOMER (VEO) MODIFIED UNSATURATED POLYESTER INTERCROSSLINKED MATRICES AND COMPOSITES

    Microsoft Academic Search

    K. Dinakaran; M. Alagar

    2003-01-01

    An intercrosslinked network of varying percentage of vinyl ester oligomer (VEO) modified unsaturated polyester matrices has been developed. Vinyl ester oligomer was prepared by reacting commercially available epoxy resins GY 250 (Ciba-Geigy) and acrylic acid and was used as toughening agent for unsaturated polyester (UP) resin. Unsaturated polyesters modified with 10%, 20% and 30% (by wt) of vinyl ester oligomer

  16. On the frequency of occurrence of a peculiar polyester fibre type found in blue denim textiles.

    PubMed

    De Wael, Kris; Baes, Christiaan; Lepot, Laurent; Gason, Fabrice

    2011-12-01

    In a double murder investigation, the victims were found after a prolonged stay in a drainage canal. In spite of the expectations, fibre examination established a multitude of primary and secondary transferred fibres. One of these fibre types was a colourless polyester fibre possessing a blue coloured molten fibre end. These matched one of the types present in the suspect's blue denim trousers. The aim of this study was to verify the rarity of this peculiar fibre type and more precisely its presence in blue denim textiles. Over five hundred different blue jeans textiles were examined and only one of these presented exactly the same type. The comparison involved microscopy, microspectrophotometry in the visible range and Raman spectroscopy. The results indicate this fibre type is extremely rare in a blue jeans fabrics and that "standard" blue denim should not be disregarded in case work. PMID:22137048

  17. Conversion of polyester/cotton industrial waste to higher value

    SciTech Connect

    Barnhardt, R.A.; Cowgill, W.P.; Walsh, W.K.; Cates, D.M.

    1986-01-01

    The primary textile industry in 1981 produced 1.5 billion pounds of blended polyester/cotton (PET/Cotton) yarns that are chiefly polyester. The polyester component, which is almost entirely poly(ethylene terephthalate) (PET), is polymerized from petroleum products and furnished to the textile industry as staple fiber. About 3% of the PET/Cotton production is waste. Although substantial markets exist for the separate products, the problem of economically separating the components has not been solved. The alternative is to develop an application for the unseparated waste. This project was undertaken to study the feasibility of using the waste blends as feedstock for injection molded plastic. Thermal and mechanical properties were determined on the compacts.

  18. Effect of Bonding Resins on the Flammability Properties and Thermal Behaviour of Cotton and Cotton\\/PESFR Woven Fabrics

    Microsoft Academic Search

    J. LEFEBVRE; M. LE BRAS; B. LEFORT; C. DREVELLE; S. DUQUESNE; M. VOUTERS; C. MAGNIEZ

    2003-01-01

    This study deals with the influence of two binder resins (acrylic and styrene-butadiene resins) on the fire properties and the thermal behaviour of cotton and cotton\\/flame retardant polyester (PESFR) textiles. Lab-scale fire testings (limiting oxygen index and vertical fire test) have shown that the impregnation of the cotton\\/polyester fabrics leads to a dramatic loss of fire performance. Therefore, a thermogravimetric

  19. A new photosensitive dielectric insulating polyester film: Synthesis and characterization

    SciTech Connect

    Shi, F.F.; Economy, J.E. [Univ. of Illinois, Urbana, IL (United States)

    1996-10-01

    In this paper, we described the synthesis and the characterization of a new dielectric insulating film prepared from a photosensitive polyester. The unique feature of this new photosensitive polyester film is that it can be foamed when cured at 280{degrees}C though interchain transesterification reaction. This process can reduce the dielectric constant of the film to 2.5. Some important properties, such as photosensitivity, thermal stability, mechanical properties of this new dielectric insulating polymer film were discussed. The preliminary results show a good resolution and an acceptable profile of this new insulator after foaming.

  20. Photoactive liquid crystalline polyesters based on bisbenzylidene and pyridine moieties

    NASA Astrophysics Data System (ADS)

    Deepa, G.; Balamurugan, R.; Kannan, P.

    2010-01-01

    Photoactive main chain liquid crystalline polyesters containing bis(benzylidene)acetone and aromatic heterocyclic pyridine were synthesized by solution polycondensation. Chemical structure of monomers and polymers were confirmed by FT-IR, 1H and 13C NMR spectroscopy. Thermal property was investigated by TGA and DSC. Optical property of polyesters was studied in chloroform solution and in thin film under UV irradiation and exhibited cis-trans-photoisomerization. This behavior was witnessed by solubility, carbonyl group absorption band in FT-IR, optical microscopy as well as DSC analysis through existence of liquid crystallinity after irradiation of polymers.

  1. Evaluation of different insecticides and fabric types for development of treated targets for stable fly (Diptera: Muscidae) control.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cloth targets, visually attractive to blood-feeding flies and treated with insecticides to kill flies when they land, were adapted for use against stable flies in rangeland situations in the U.S. Five candidate fabrics were tested and trigger fabric (polyester/cotton) best maintained pesticide resi...

  2. Thermal degradation of short polyester fiber-polyurethane elastomer composite

    Microsoft Academic Search

    F. Suhara; S. K. N. Kutty; G. B. Nando

    1998-01-01

    The thermal degradation of short polyester fiber reinforced polyurethane composites with and without different bonding agents has been studied by thermogravimetric analysis. It was found that degradation of the polyurethane takes place in two steps and that of the composites takes place in three steps. With the incorporation of 30 phr of fiber in the matrix, the onset of degradation

  3. Modification of polyester resin based composites induced by seawater absorption

    Microsoft Academic Search

    A. M. Visco; L. Calabrese; P. Cianciafara

    2008-01-01

    This research is a study on seawater absorption ability and on mechanical performance (before and after immersion in seawater) of two composites that basically differ for what concerns the polyester resin (isophthalic or orthophthalic) employed in boats manufacture. Experimental tests, carried out on the two resins, evidenced that they differ for what concerns their structural organization, water diffusion coefficient, thermal

  4. Organic Rectorite-modified Unsaturated Polyester Resin Composites

    Microsoft Academic Search

    Li Yuan; Xiao-Yan Ma; Guo-Zheng Liang; Yun Huang

    2007-01-01

    In this study, rectorite (REC), being a type of layered silicates, has been applied to the polymer to improve its properties. The glass fiber-reinforced polymer-layered silicate clay composites are a new option to modify the properties of the polymer. In the present study, unsaturated polyester resins (UP) are modified by organic rectorite (OREC) to improve the mechanical properties of UP

  5. Bacterial and other biological systems for polyester production

    Microsoft Academic Search

    Alexander Steinbüchel; Bernd Füchtenbusch

    1998-01-01

    Poly(3-hydroxybutyric acid) and other structurally related aliphatic polyesters from bacteria, referred to as polyhydroxyalkanoic acids, form biodegradable thermoplastics and elastomers that are currently in use, or being considered for use, in industry, medicine, pharmacy and agriculture. At present, they are produced by microbial fermentations; in the future, production will also be possible by in vitro methods or by agriculture using

  6. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, T.; Kukacka, L.E.; Horn, W.H.

    1981-11-04

    Quick setting polymer concrete compositions which are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate which may be wet and a source of bivalent metallic ions which will set to polymer concrete with excellent structural properties.

  7. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, Toshifumi (Mastic Beach, NY); Kukacka, Lawrence E. (Port Jefferson, NY); Horn, William H. (Brookhaven, NY)

    1985-01-01

    Quick setting polymer concrete compositions with excellent structural properties are disclosed; these polymer concrete compositions are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate, which may be wet, and with a source of bivalent metallic ions.

  8. Interior microelectrolysis oxidation of polyester wastewater and its treatment technology

    Microsoft Academic Search

    Xiaoyi Yang

    2009-01-01

    This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by

  9. Dynamic mechanical analysis of banana fiber reinforced polyester composites

    Microsoft Academic Search

    Laly A. Pothan; Zachariah Oommen; Sabu Thomas

    2003-01-01

    The dynamic mechanical analysis of banana fiber reinforced polyester composites was carried out with special reference to the effect of fiber loading, frequency and temperature. The intrinsic properties of the components, morphology of the system and the nature of interface between the phases determine the dynamic mechanical properties of the composite. At lower temperatures (in the glassy region), the E?

  10. Melt rheology of aliphatic hyperbranched polyesters with various molecular weights

    Microsoft Academic Search

    T.-T Hsieh; C Tiu; G. P Simon

    2001-01-01

    Rheological behaviour of a series of aliphatic hyperbranched polyesters, Boltorn polymers, with different molecular weights (generations) is studied in the molten state. The onset of a nonlinear region occurs at much lower strains for Boltorn polymers of lower generations (generation 2 and 3) compared with those of higher generations (generation 4 and 5) in the dynamic strain sweep experiments. Relaxation

  11. Degradation Characterization of Aliphatic POLYESTERS—IN Vitro Study

    NASA Astrophysics Data System (ADS)

    Vieira, A. C.; Vieira, J. C.; Guedes, R. M.; Marques, A. T.

    2008-08-01

    The most popular and important biodegradable polymers are aliphatic polyesters, such as polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), polyhydoxyalkanoates (PHA's) and polyethylene oxide (PEO). However, each of these has some shortcomings which restrict its applications. Blending techniques are an extremely promising approach which can improve or tune the original properties of the polymers[1]. Aliphatic polyesters are a central class of biodegradable polymers, because hydrolytic and/or enzymatic chain cleavage of these materials leads to ?-hydroxyacids, which in most cases are ultimately metabolized in human body. This is particularly useful for controlled release devices and for other biomedical applications like suture fibers and ligaments. For aliphatic polyesters, hydrolysis rates are affected by the temperature, molecular structure, and ester group density as well as by the species of enzyme used. The degree of crystallinity may be a crucial factor, since enzymes attack mainly the amorphous domains of a polymer. Four different aliphatic polyesters were characterized in terms of degradation. Sutures fibers of PGA-PCL, PGA, PLA-PCL and PDO were used in this study. Weight loss, pH, molecular weight, crystallinity and strength were measured after six stages of incubation in distilled water, physiological saline and phosphate buffer solution (PBS). Degradation rate was determined, using a first order kinetic equation for all materials in the three incubation media. A relatively wide range of mechanical properties and degradation rates were observed among the materials studied. PBS was the most aggressive environment for the majority of cases.

  12. Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete

    DOEpatents

    Sugama, T.; Kukacka, L.E.; Horn, W.H.

    1983-05-13

    Quick setting polymer concrete compositions are described which are mixtures of unsaturated polyesters and crosslinking monomers together with appropriate initiators and promoters in association with aggregate which may be wet and a source of bivalent metallic ions which will set to polymer concrete with excellent structural properties.

  13. Amphiphilic Dendritic Molecules: Hyperbranched Polyesters with Alkyl-Terminated Branches

    E-print Network

    Vakni, David

    Amphiphilic Dendritic Molecules: Hyperbranched Polyesters with Alkyl-Terminated Branches X. Zhai, S for a controlling amphiphilic balance of hyperbranched cores with a degree of branching of 50%. Even for imperfect dendritic molecules capable of forming organized aggregates and monolayers at interfaces, amphiphilic

  14. Photoacoustic measurement of thermal properties of a thin polyester film

    Microsoft Academic Search

    André Lachaine; Patrick Poulet

    1984-01-01

    The phase and the amplitude of the photoacoustic signal are measured as a function of chopping frequency for a thin polyester film, using two different backing materials (water and ethanol). Analysis of the results shows agreement with Rosencwaig–Gersho theory [J. Appl. Phys. 47, 64 (1976)] and provides values of the thermal diffusivity and the thermal effusivity of the sample.

  15. Modification of polyester resins with active mineral fillers

    Microsoft Academic Search

    A. V. Murafa; N. I. Bobyreva; V. G. Khozin

    1996-01-01

    The technological and operational properties of polyester resins, unmodified and modified with new freely disperse fillers, were investigated. It was found that modification causes greater dependence of the viscosity on the fatigue load and acceleration of the curing reaction and an increase in the exothermic effect by 2.5-4.5 times. In addition, the strength properties of the modified composites and the

  16. Synthesis, structure and properties of polyhydroxyalkanoates: biological polyesters

    Microsoft Academic Search

    K Sudesh; H Abe; Y Doi

    2000-01-01

    High molecular weight polyhydroxyalkanoates (PHA) are synthesized and stored in the cell cytoplasm as water-insoluble inclusions by various microorganisms. This intriguing biological polyester initially attracted the attention of microbiologists and managed to keep many polymer scientists occupied over the second half of the last century. Concerted multidisciplinary scientific approaches have been directed to the elucidation of various aspects of PHA.

  17. A comparison of tensile properties of polyester composites reinforced with pineapple leaf fiber and pineapple peduncle fiber

    NASA Astrophysics Data System (ADS)

    Juraidi, J. M.; Shuhairul, N.; Syed Azuan, S. A.; Intan Saffinaz Anuar, Noor

    2013-12-01

    Pineapple fiber which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for polymer reinforcement. This research presents a study of the tensile properties of pineapple leaf fiber and pineapple peduncle fiber reinforced polyester composites. Composites were fabricated using leaf fiber and peduncle fiber with varying fiber length and fiber loading. Both fibers were mixed with polyester composites the various fiber volume fractions of 4, 8 and 12% and with three different fiber lengths of 10, 20 and 30 mm. The composites panels were fabricated using hand lay-out technique. The tensile test was carried out in accordance to ASTM D638. The result showed that pineapple peduncle fiber with 4% fiber volume fraction and fiber length of 30 mm give highest tensile properties. From the overall results, pineapple peduncle fiber shown the higher tensile properties compared to pineapple leaf fiber. It is found that by increasing the fiber volume fraction the tensile properties has significantly decreased but by increasing the fiber length, the tensile properties will be increased proportionally. Minitab software is used to perform the two-way ANOVA analysis to measure the significant. From the analysis done, there is a significant effect of fiber volume fraction and fiber length on the tensile properties.

  18. Thermo-mechanical properties of polyester mortar using recycled PET

    SciTech Connect

    Rebeiz, K.S.; Craft, A.P. [Lafayette Coll., Easton, PA (United States)

    1997-07-01

    The thermo-mechanical properties of polyester mortar (PM) using unsaturated polyester resins based on recycled PET are investigated in this paper (the recycled PET waste is mainly obtained from used plastic beverage bottles). The use of recycled PET in PM formulation is important because it helps produce good quality PM at a relatively low cost, save energy and alleviate an environmental problem posed by plastic wastes. PM construction applications include the repair of dams, piers, runways, bridges and other structures. Test results show that the effective use of PM overlays on portland cement concrete slabs is best achieved by utilizing flexible resins with low modulus and high elongation capacity at failure. The use of flexible resins in PM production is especially important in situations involving large thermal movements.

  19. Biosynthesis and biodegradation of 3-hydroxypropionate-containing polyesters.

    PubMed

    Andreessen, Björn; Steinbüchel, Alexander

    2010-08-01

    3-Hydroxypropionate (3HP) is an important compound in the chemical industry, and the polymerized 3HP can be used as a bioplastic. In this review, we focus on polyesters consisting of 3HP monomers, including the homopolyester poly(3-hydroxypropionate) and copolyesters poly(3-hydroxybutyrate-co-3-hydroxypropionate), poly(3-hydroxypropionate-co-3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyoctanoate), poly(4-hydroxybutyrate-co-3-hydroxypropionate-co-lactate), and poly(3-hydroxybutyrate-co-3-hydroxypropionate-co-4-hydroxybutyrate-co-lactate). Homopolyesters like poly(3-hydroxybutyrate) are often highly crystalline and brittle, which limits some of their applications. The incorporation of 3HP monomers reduces the glass transition temperature, the crystallinity, and also, at up to 60 to 70 mol% 3HP, the melting point of the copolymer. This review provides a survey of the synthesis and physical properties of different polyesters containing 3HP. PMID:20543057

  20. Transcaval access for TAVR across a polyester aortic graft.

    PubMed

    Lederman, Robert J; O'Neill, William W; Greenbaum, Adam B

    2015-06-01

    Transcaval access to the aorta allows transcatheter aortic valve replacement in patients without other good access options. The resulting aorto-caval fistula is closed with a nitinol cardiac occluder device. There is no experience traversing a synthetic aortic graft to perform transcaval access and closure. We describe a patient who underwent successful traversal of a polyester aortic graft using radiofrequency energy applied from the tip of a guidewire, to allow retrograde transcatheter aortic valve replacement from a femoral vein, along with details of our technique. The patient did well and was discharged home after 3 days. There was residual aorto-caval fistulous flow immediately after implantation of a polyester-seeded nitinol muscular ventricular septal defect occluder device, but this fistula spontaneously occluded within one month. © 2015 Wiley Periodicals, Inc. PMID:25510917

  1. Biosynthesis and Biodegradation of 3-Hydroxypropionate- Containing Polyesters?

    PubMed Central

    Andreeßen, Björn; Steinbüchel, Alexander

    2010-01-01

    3-Hydroxypropionate (3HP) is an important compound in the chemical industry, and the polymerized 3HP can be used as a bioplastic. In this review, we focus on polyesters consisting of 3HP monomers, including the homopolyester poly(3-hydroxypropionate) and copolyesters poly(3-hydroxybutyrate-co-3-hydroxypropionate), poly(3-hydroxypropionate-co-3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyoctanoate), poly(4-hydroxybutyrate-co-3-hydroxypropionate-co-lactate), and poly(3-hydroxybutyrate-co-3-hydroxypropionate-co-4-hydroxybutyrate-co-lactate). Homopolyesters like poly(3-hydroxybutyrate) are often highly crystalline and brittle, which limits some of their applications. The incorporation of 3HP monomers reduces the glass transition temperature, the crystallinity, and also, at up to 60 to 70 mol% 3HP, the melting point of the copolymer. This review provides a survey of the synthesis and physical properties of different polyesters containing 3HP. PMID:20543057

  2. Synthesis, characterization, and biological evaluation of new polyester containing Schiff base metal complexes

    Microsoft Academic Search

    Nahid Nishat; Sumaiya Hasnain; Tansir Ahmad; Asma Parveen

    The production of new biocidal polyester Schiff base metal complexes [PESB–M(II)] via polycondensation reaction between chelated\\u000a Schiff base diol and adipoyl chloride is reported. The resulting polyesters were characterized by physico-chemical and spectroscopic\\u000a methods. The analytical data of all the synthesized polyesters were found to be in good agreement with 1:1 molar ratio of\\u000a chelated Schiff base diol to adipoyl

  3. Stabilization of Rigid Systems Containing Aromatic Polyester Polyol and Water

    Microsoft Academic Search

    CARINA A. MCADAMS; STEVEN FARMER

    2003-01-01

    With the phase-out of hydrochlorofluorocarbon blowing agents at hand, a challenge facing polyester polyol producers is providing products to the polyurethane industry suitable for use with next generation blowing agents. New products must produce foams with an excellent balance of properties and concurrently maintain cost-effectiveness. As the choices of the alternative blowing agents post HCFC-141b become more defined, it is

  4. Biodiversity of microorganisms that degrade bacterial and synthetic polyesters

    Microsoft Academic Search

    J Mergaert; J Swings

    1996-01-01

    The biodiversity and occurrence in nature of bioplastic-degrading microorganisms are exemplified by the identification of 695 strains, isolated from different environments, such as soils, composts, natural waters, and sludge, that are able to degrade the bacterial polyester poly(3-hydroxybutyrate)in vitro. These microorganisms belong to at least 57 different taxa, including Gram-negative and Gram-positive bacteria, streptomycetes, and moulds. The literature on the

  5. Resource conservation through beverage-container recycling. [Polyester (PET) bottles

    Microsoft Academic Search

    L. L. Gaines; A. M. Wolsky

    1982-01-01

    Since the introduction of plastic soft-drink bottles in 1977, the 2 liter container has captured almost the entire US market. The number of PET (polyethylene terephthalate, a polyester) bottles used in 1981 was 2.4 billion, and could grow to 14 billion by 1990 if the penetration into the 1\\/2 liter market is as rapid as some experts predict. Consumers value

  6. Poly( ?-caprolactone) + unsaturated isophtalic polyester blends: Thermal properties and morphology

    Microsoft Academic Search

    C. Salom; D. Nava; M. G. Prolongo; R. M. Masegosa

    2006-01-01

    Miscibility of blends composed by a linear unsaturated polyester (LUP) with poly(?-caprolactone) (PCL) of different molecular weights (Mw=50×103, 18×103 and 2×103) has been studied. The blends were subjected to different thermal treatments and have been studied by FT-IR spectroscopy, differential scanning calorimetry (DSC) and scanning electronic microscopy (ESEM). FT-IR results allow proving the miscibility of the blends at temperatures above

  7. Adhesive behavior of aluminum layers evaporated on polyester films

    SciTech Connect

    Vallat, M.F.; Haidara, H.; Ziegler, P.; Rey, D.; Papirer, Y.; Schultz, J. [Centre de Recherches sur la Physico-Chimie des Surfaces Solides (UPR 6601 CNRS) 24, avenue du President Kennedy 68200 Mulhouse (France)

    1996-01-01

    The adhesive performance of thin aluminum coatings deposited onto polymer substrates is considered. The effects of the evaporation conditions and the metal thickness on the adhesive properties of polyester/aluminum assemblies are examined. A ultrasonic test for adherence measurements of thin metal layers is proposed and its shown that a thermal treatment under stress modifies the adhesive properties of such metallized polymer films. (AIP) {copyright}{ital 1996 American Institute of Physics.}

  8. Radiation-thickening of iso-polyester resin

    NASA Astrophysics Data System (ADS)

    Czayka, M.; Fisch, M.; Uribe, Roberto M.; Vargas–Aburto, C.

    2007-06-01

    A novel method to thicken iso-polyester resins using high-energy electrons is presented along with data characterizing the physical, structural, and thermal properties of the gelled-resin using compressive testing, DSC and IR spectroscopy. Additional data are presented on the tensile properties of a cured composite, made from a radiation-thickened molding compound, compared to traditional chemically thickened compound using the same base resin.

  9. Hydrolytic ageing of polyester networks - Role of a plasticizer

    NASA Astrophysics Data System (ADS)

    Richaud, Emmanuel; Derue, Isabelle; Gilormini, Pierre; Verdu, Jacques; Coquillat, Marie; Vandenbrouke, Aude; Desgardin, Nancy

    2014-05-01

    This paper reports the hydrolytic ageing of polyester urethane based elastomer networks containing various amount of a plasticizer. Degradation was monitored by mechanical properties and swelling ratio changes. An analysis of the early stages of degradation showed this plasticizer decreased the polymer sensitivity towards hydrolysis. Some possible reasons were discussed. The most likely is that adding plasticizer during polymerization changes the network initial architecture with more dangling chains of which hydrolysis does not change the elastic properties.

  10. Blends of polyester ionomers with polar polymers: Interactions, reactions, and compatibilization

    NASA Astrophysics Data System (ADS)

    Boykin, Timothy Lamar

    The compatibility of amorphous and semicrystalline polyester ionomers with various polar polymers (i.e., polyesters and polyamides) has been investigated for their potential use as minor component compatibilizers. The degree of compatibility (i.e., ranging from incompatible to miscible) between the polyester ionomers and the polar polymers was determined by evaluating the effect of blend composition on the melting behavior and phase behavior of binary blends. In addition, the origin of compatibility and/or incompatibility for each of the binary blends (i.e., polyamide/ionomer and polyester/ionomer) was determined by evaluating blends prepared by both solution and melt mixed methods. Subsequent to investigation of the binary blends, the effect of polyester ionomer addition on the compatibility of polyamide/polyester blends was investigated by evaluating the mechanical properties and phase morphology of ionomer compatibilized polyamide/polyester blends. Polyester ionomers (amorphous and semicrystalline) were shown to exhibit a high degree of compatibility (even miscibility) with polyamides, such as nylon 6,6 (N66). Compatibility was attributed to specific interactions between the metal counterion of the polyester ionomer and the amide groups of N66. The degree of compatibility (or miscibility) was shown to be dependent on the counterion type of the ionomer, with the highest degree exhibited by blends containing the divalent form of the polyester ionomers. Although polyester ionomers were shown to exhibit incompatibility with both poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT), increasing the time of melt processing significantly enhanced the compatibility of the polyester ionomers with both PET and PBT. The observed enhancement in compatibility was attributed to ester-ester interchange between the polyester blend components, which was confirmed by NMR spectroscopy. The addition of polyester ionomers as a minor component compatibilizer (i.e., 2 to 5 wt%) resulted in significant enhancement in the impact strength and a dramatic improvement in the tensile properties compared to uncompatibilized blends of nylon 6,6 (N66) with poly(butylene terephthalate) (PBT). This behavior was attributed to an increase in the interfacial adhesion between the phase-separated domains due to strong interactions between the polyester ionomer and N66. The placement of the ionomer compatibilizer at the N66/PBT interface was facilitated by pre-extrusion of the polyester ionomer with PBT, prior to extrusion with N66.

  11. FINISHING FABRICATED METAL PRODUCTS WITH POWDER COATING. Project Summary (EPA/600/SR-96/152)

    EPA Science Inventory

    This report provides a technical and economic evaluation of a polyester powder coating system applied to the exterior and interior surfaces of metal boxes fabricated for the telephone and cable industries. This evaluation summarized many of the requirements and benefits of a clea...

  12. Fabrication and testing of natural fibre composites: Vakka, sisal, bamboo and banana

    Microsoft Academic Search

    K. Murali Mohan Rao; K. Mohana Rao; A. V. Ratna Prasad

    2010-01-01

    A study has been carried out to investigate the tensile, flexural and dielectric properties of composites made by reinforcing vakka as a new natural fibre into a polyester resin matrix. The fibres extracted by retting and manual processes have been used to fabricate the composites. These composites are tested for tensile, flexural and dielectric properties and compared with those of

  13. PHOTOCATALYTIC DEGRADATION OF TOLUENE vapour USING FIXED BED MULTICHANNEL PHOTOREACTORS EQUIPPED WITH TiO2?COATED FABRICS

    Microsoft Academic Search

    2008-01-01

    The feasibility of producing TiO2?coated fabric using nonwoven polyester as a photocatalyst support was examined through investigations on (i) changes in the fabric properties after coating with TiO2, (ii) the toluene removal capacity of a multichannel TiO2\\/fabric\\/UV reactor in removing the toluene vapour with and without O3 addition, and (iii) the photocatalytic effect of regenerated TiO2. The value and usefulness

  14. Wood fiber reinforced bacterial bioplastic composites: Fabrication and performance evaluation

    Microsoft Academic Search

    Sanjeev Singh; A. K. Mohanty

    2007-01-01

    Renewable resource based green composites were prepared from wood fiber and a bacterial polyester i.e., polyhydroxybutyrate-co-valerate (PHBV) via extrusion–injection molding process. The fabricated PHBV based biocomposites contained 10–40wt% of the maple wood fiber. The effects of increasing wood fiber weight contents on mechanical, thermomechanical and morphological properties of the PHBV based biocomposites were evaluated. The tensile and flexural modulus of

  15. Releasing dye encapsulated in proteinaceous microspheres on conductive fabrics by electric current.

    PubMed

    Shimanovich, Ulyana; Perelshtein, Ilana; Cavaco-Paulo, Artur; Gedanken, Aharon

    2012-06-27

    The current paper reports on the relase properties of conductive fabrics coated with proteinaceous microspheres containing a dye. The release of the dye was achieved by passing an electric current through the fabric. The conductivity of the polyester fibers resulted from nanosilver (Ag NPs) coated on the surface of these fibers. Both types of coatings (nanosilver coating and the coating of the proteinaceous microspheres) were performed using high-intensity ultrasonic waves. Two different types of dyes, hydrophilic RBBR (Remazol Brilliant Blue R) and hydrophobic ORO (Oil Red O), were encapsulated inside the microspheres (attached to the surface of polyester) and then released by applying an electric current. The Proteinaceous Microsphere (PM)-coated conductive fabrics could be used in medicine for drug release. The encapsulated dye can be replaced with a drug that could be released from the surface of fabrics by applying a low voltage. PMID:22551441

  16. COMPATIBILITY AND MECHANICAL PROPERTIES OF BLENDS OF POLYSTYRENE WITH BIODEGRADABLE POLYESTERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodegradable polyesters are critical components in the development of biomaterials from synthetic and/or natural polymers. Manufacture of useful blends requires that the biodegradable polyesters be compatible with the polymers they are blended with. Compatibility is evaluated by measuring the int...

  17. Modelling the cure of a gelcoat film made of unsaturated polyester

    Microsoft Academic Search

    A. Sahli; R. Granger; J. M. Vergnaud

    1995-01-01

    A gelcoat made of pure unsaturated polyester and deposited on the surface of a loaded polyester is studied. The problem of the cure of a gelcoat is considered by taking into account heat evolved from the cure reaction, heat transferred by conduction through the resin and support and heat convection on the surface. The kinetics of heat generated by the

  18. COMPATIBILITY AND MECHANICAL PROPERTIES OF BLENDS OF POLYSYTRENE WITH BIODEGRADABLE POLYESTERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodegradable polyesters allow the development of acceptable bio-composites and bio-blends from ag-based raw materials without impairing their biodegradability and other useful properties. The tensile properties of binary blends of polystyrene (PS) with the biodegradable polyesters polycaprolactone...

  19. Infrared linear dichroism study of a hydrolytically degraded poly(ester urethane)

    Microsoft Academic Search

    Jon R. Schoonover; Darla Graff Thompson; Jill C. Osborn; E. Bruce Orler; Debra A. Wrobleski; Anderson L. Marsh; Haochuan Wang; Richard A. Palmer

    2001-01-01

    Static and dynamic infrared linear dichroism data have been used to supply additional insight into changes in tensile properties as a consequence of hydrolytic degradation of a segmented poly(ester urethane). Unaged material responds to tensile deformation with the soft (polyester) segments supplying the elasticity and the hard (polyurethane) segments supplying strength. Upon hydrolytic degradation, the static and dynamic data indicate

  20. In vitro degradation study of polyester microspheres by a new HPLC method for monomer release determination

    Microsoft Academic Search

    P Giunchedi; B Conti; S Scalia; U Conte

    1998-01-01

    Biodegradable polyesters have increasing importance as materials used for the preparation of microspheres. The knowledge of their degradation process is important to prepare microparticulate delivery systems with suitable drug release rates. In this work an in vitro degradation study of empty and drug loaded microspheres is described. Three different polyesters were used: two poly-d,l-lactides of different molecular weight and a

  1. Instrumented impact testing of fabric-reinforced composite materials. Research and development report

    SciTech Connect

    Juska, T.D.; Crane, R.M.; Mixon, T.

    1989-05-01

    Instrumented impact and ultrasonic inspection were used to assess the impact damage resistance of six fabric-reinforced laminates. Polyester and vinylester resins reinforced with woven roving, biaxial reinforcement, and glass/Kevlar hybrid were evaluated. Biaxial fabric reinforced resins had the best impact resistance. This determination is based on the ability of these materials to survive impact with the lowest friction of impact energy resulting in damage. In addition laminates with biaxial reinforcement ahd comparable damage areas to the other materials.

  2. Aliphatic polyesters: great degradable polymers that cannot do everything.

    PubMed

    Vert, Michel

    2005-01-01

    Nowadays the open and the patent literatures propose a large number of polymers whose main chains can be degraded usefully. Among these degradable polymers, aliphatic polyester-based polymeric structures are receiving special attention because they are all more or less sensitive to hydrolytic degradation, a feature of interest when compared with the fact that living systems function in aqueous media. Only some of these aliphatic polyesters are enzymatically degradable. A smaller number is biodegradable, and an even more limited number is biorecyclable. To be of practical interest, a degradable polymer must fulfill many requirements that depend very much on the targeted application, on the considered living system, and on living conditions. It is shown that aliphatic polyester structures made of repeating units that can generate metabolites upon degradation or biodegradation like poly(beta-hydroxy alkanoate)s and poly(alpha-hydroxy alkanoate)s are of special interest. Their main characteristics are confronted to the specifications required by various potential sectors of applications, namely, surgery, pharmacology, and the environment. It is shown that degradation, bioresorption, and biorecycling that are targets when one wants to respect living systems are also drastic limiting factors when one wants to achieve a device of practical interest. Finding a universal polymer that would be the source of all the polymeric biomaterials needed to work in contact with living organisms of the various life kingdoms and respect them remains a dream. On the other hand, finding one polymeric structure than can fulfill the requirements of one niche application remains a big issue. PMID:15762610

  3. Engineered Hypopharynx from Coculture of Epithelial Cells and Fibroblasts Using Poly(ester urethane) as Substratum

    PubMed Central

    Shen, Zhisen; Chen, Jingjing; Kang, Cheng; Gong, Changfeng

    2013-01-01

    Porous polymeric scaffolds have been much investigated and applied in the field of tissue engineering research. Poly(ester urethane) (PEU) scaffolds, comprising pores of 1–20??m in diameter on one surface and ?200??m on the opposite surface and in bulk, were fabricated using phase separation method for hypopharyngeal tissue engineering. The scaffolds were grafted with silk fibroin (SF) generated from natural silkworm cocoon to enhance the scaffold's hydrophilicity and further improve cytocompatibility to both primary epithelial cells (ECs) and fibroblasts of human hypopharynx tissue. Coculture of ECs and fibroblasts was conducted on the SF-grafted PEU scaffold (PEU-SF) to evaluate its in vitro cytocompatibility. After co-culture for 14 days, ECs were lined on the scaffold surface while fibroblasts were distributed in scaffold bulk. The results of in vivo investigation showed that PEU porous scaffold possessed good biocompatibility after it was grafted by silk fibroin. SF grafting improved the cell/tissue infiltration into scaffold bulk. Thus, PEU-SF porous scaffold is expected to be a good candidate to support the hypopharynx regeneration. PMID:24455669

  4. Hygrothermomechanical evaluation of transverse filament tape epoxy/polyester fiberglass composites

    NASA Technical Reports Server (NTRS)

    Lark, R. L.; Chamis, C. C.

    1983-01-01

    The static and cyclic load behavior of transverse filament tape (TFT) fiberglass/epoxy and TFY fiberglass/polyester composites, intended for use in the design of low-cost wind turbine blades, are presented. The data behavior is also evaluated with respect to predicted properties based on an integrated hygrothermomechanical response theory. Experimental TFT composite data were developed by the testing of laminates made by using composite layups typical of those used for the fabrication of TFT fiberglass wind turbine blades. Static properties include tension, compression, and interlaminar shear strengths at ambient conditions and at high humidity/elevated temperature conditions after a 500 hour exposure. Cyclic fatigue data were obtained using similar environmental conditions and a range of cyclic stresses. The environmental (temperature and moisture) and cyclic load effects on composite strength degradation are subsequently compared with the predictions obtained by using the composite life/durability theory. The results obtained show that the predicted hygrothermomechanical environmental effects on TFT composites are in good agreement with measured data for various properties including fatigue at different cyclic stresses.

  5. Fabrication and Characterization of PLA-PGA Orthopedic Implants.

    PubMed

    Agrawal, C M; Niederauer, G G; Athanasiou, K A

    1995-01-01

    Fabrication methods and property characterization of polyglycolic acid (PGA), polylactic acid (PLA), and their copolymers are reviewed. Both of these aliphatic polyesters belong to the a-hydroxy group and biodegrade in a physiological environment to monomeric acids, which are readily processed and excreted from the body. The physical and mechanical characteristics discussed include molecular weight, crystallinity, stress-strain behavior, permeability, and melting/glass transition temperatures. The most common methods of fabricating PLA-PGA materials into medical devices are described. PMID:19877903

  6. Development of biodegradable crosslinked urethane-doped polyester elastomers

    PubMed Central

    Dey, Jagannath; Xu, Hao; Shen, Jinhui; Thevenot, Paul; Gondi, Sudershan R.; Nguyen, Kytai T.; Sumerlin, Brent S.; Tang, Liping; Yang, Jian

    2009-01-01

    Traditional crosslinked polyester elastomers are inherently weak, and the strategy of increasing crosslink density to improve their mechanical properties makes them brittle materials. Biodegradable polyurethanes, although strong and elastic, do not fare well in dynamic environments due to the onset of permanent deformation. The design and development of a soft, strong and completely elastic (100% recovery from deformation) material for tissue engineering still remains a challenge. Herein, we report the synthesis and evaluation of a new class of biodegradable elastomers, crosslinked urethane-doped polyesters (CUPEs), which is able to satisfy the need for soft, strong, and elastic biomaterials. Tensile strength of CUPE was as high as 41.07 ± 6.85 MPa with corresponding elongation at break of 222.66 ± 27.84%. The initial modulus ranged from 4.14 ± 1.71 MPa to 38.35 ± 4.5 MPa. Mechanical properties and degradation rates of CUPE could be controlled by varying the choice of diol used for synthesis, the polymerization conditions, as well as the concentration of urethane bonds in the polymer. The polymers demonstrated good in vitro and in vivo biocompatibilities. Preliminary hemocompatibility evaluation indicated that CUPE adhered and activated lesser number of platelets compared to PLLA. Good mechanical properties and easy processability make these materials well suited for soft tissue engineering applications. The introduction of CUPEs provides new avenues to meet the versatile requirements of tissue engineering and other biomedical applications. PMID:18801566

  7. Composite material from recycled polyester for recyclable automobile structures

    SciTech Connect

    Lertola, J.G. [DuPont Company, Newark, DE (United States)

    1995-12-31

    DuPont has developed a compression-moldable composite made from the thermoplastic polyester PET and long glass fibers. This material, XTC{trademark}, is part of the class of materials known as GMT`s, or glass-mat thermoplastics. The PET content in XTC{trademark} allows the use of a wide variety of recycled material that might otherwise end up in landfills and incinerators. DuPont has succeeded in using 100% post-consumer polyester, from bottles, film, or fibers, in the composite. Since processing involves heating the material to the melt in air, the main technical issues are hydrolysis and oxidative degradation. Impurities in the recycled material must be carefully monitored, as they often increase the extent of degradation. The product itself, used to mold shaped structures and body panels for automobiles, may be recycled after its useful life. Depending on the needed purity level, processes ranging from injection molding to methanolysis can turn ground XTC{trademark} parts back into new, useful products.

  8. Hyperbranched aliphatic polyesters and reactive diluents in thermally cured coil coatings.

    PubMed

    Johansson, Katarina; Bergman, Tina; Johansson, Mats

    2009-01-01

    Two hydroxy-functional hyperbranched aliphatic polyesters based on 2,2-dimethylolpropionic acid (bis-MPA) and a partially aromatic conventional polyester have been studied as thermoset resins for solvent-borne thermally cured polyester cross-linked with melamine coatings for precoated sheet metal, i.e., coil coatings. The hyperbranched polyesters differ with respect to the ratio of the end groups, being either hydroxyls or alkyl esters. The rheological properties of formulations with different polyester resin composition and reactive diluent, i.e., rape seed methyl ester, content have been evaluated with viscosity measurements. Films cured either under industrial cure conditions to obtain a peak metal temperature of 232-241 degrees C or at a lower temperature, i.e., 130 degrees C, on untreated or organic primer-coated hot-dipped-galvanized steel substrates have been prepared. The film properties have been evaluated with differential scanning calorimetry and conventional film characterization techniques, i.e., adhesion, impact, Erichsen cupping, pencil hardness, microhardness, and scratch and chemical resistance tests. Formulations possessing high drying ability with maintained suitable film application viscosity were obtained using a hyperbranched polyester resin and a reactive diluent. It is proposed that a solvent-free polyester/melamine formulation with sufficient film properties to withstand the rough forming procedures associated with coil coatings can be obtained by further modification of the resin and greater amounts of reactive diluent. PMID:20355774

  9. Functional finishing of aminated polyester using biopolymer-based polyelectrolyte microgels.

    PubMed

    Glampedaki, Pelagia; Dutschk, Victoria; Jocic, Dragan; Warmoeskerken, Marijn M C G

    2011-10-01

    This study focuses on a microgel-based functionalization method applicable to polyester textiles for improving their hydrophilicity and/or moisture-management properties, eventually enhancing wear comfort. The method proposed aims at achieving pH-/temperature-controlled wettability of polyester within a physiological pH/temperature range. First, primary amine groups are created on polyester surfaces using ethylenediamine; second, biopolymer-based polyelectrolyte microgels are incorporated using the natural cross-linker genipin. The microgels consist of the pH-responsive natural polysaccharide chitosan and pH/thermoresponsive poly(N-isopropylacrylamide-co-acrylic acid) microparticles. Scanning electron microscopy confirmed the microgel presence on polyester surfaces. X-ray photoelectron spectroscopy revealed nitrogen concentration, supporting increased microscopy results. Electrokinetic analysis showed that functionalized polyester surfaces have a zero-charge point at pH 6.5, close to the microgel isoelectric point. Dynamic wetting measurements revealed that functionalized polyester has shorter total water absorption time than the reference. This absorption time is also pH dependent, based on dynamic contact angle and micro-roughness measurements, which indicated microgel swelling at different pH values. Furthermore, at 40 °C functionalized polyester has higher vapor transmission rates than the reference, even at high relative humidity. This was attributed to the microgel thermoresponsiveness, which was confirmed through the almost 50% decrease in microparticle size between 20 and 40 °C, as determined by dynamic light scattering measurements. PMID:21751392

  10. Degradable Nitric Oxide-Releasing Biomaterials via Post-Polymerization Functionalization of Crosslinked Polyesters

    PubMed Central

    Coneski, Peter N.; Rao, Kavitha S.; Schoenfisch, Mark H.

    2010-01-01

    The synthesis of diverse nitric oxide (NO)-releasing network polyesters is described. The melt phase condensation of polyols with a calculated excess of diacid followed by thermal curing generates crosslinked polyesters containing acid end groups. Varying the composition and curing temperatures of the polyesters resulted in materials with tunable thermal and degradation properties. Glass transition temperatures for the synthesized materials range from ?25.5 °C to 3.2 °C, while complete degradation of these polyesters occurs within a minimum of nine weeks under physiological conditions (pH 7.4, 37 °C). Post-polymerization coupling of aminothiols to terminal carboxylic acids generate thiol-containing polyesters, with thermal and degradation characteristics similar to those of the parent polyesters. After nitrosation, these materials are capable of releasing up to 0.81 ?mol NO cm?2 for up to 6 d. The utility of the polyesters as antibacterial biomaterials was indicated by an 80% reduction of Pseudomonas aeruginosa adhesion compared to unmodified controls. PMID:20954726

  11. Preparation of rich handles soft cellulosic fabric using amino silicone based softener, part II: colorfastness properties.

    PubMed

    Zuber, Mohammad; Zia, Khalid Mahmood; Tabassum, Shazia; Jamil, Tahir; Barkaat-Ul-Hasin, Syed; Khosa, Muhammad Kaleem

    2011-07-01

    The preparation of amino silicone based softeners with different emulsifiers was carried out and adsorbed onto the surfaces of cotton and blends of cotton/polyester fabrics. The softened fabrics have high surface area, so poorly performance in washing and rubbing fastness. It is obvious from the results of colorfastness to rubbing and washing that some of the samples of the dyed fabric treated with prepared softeners have shown some poor rating as compared to the untreated fabrics. However the other two samples have shown acceptable rubbing fastness results without losing softness and permanent handle. It can be observed that washing of the printed treated fabric remains unaffected almost in all the studied samples. Moreover, the application of the prepared softeners has imparted anti pilling property to the fabric. It can be seen that there is a remarkable increase in weights of treated fabrics as compared to the untreated fabrics. PMID:21300085

  12. Polyalkylenehydroxybenzoates (PAHBs): biorenewable aromatic/aliphatic polyesters from lignin.

    PubMed

    Mialon, Laurent; Vanderhenst, Rob; Pemba, Alexander G; Miller, Stephen A

    2011-09-01

    Polyalkylenehydroxybenzoates (PAHBs) are a new class of thermoplastic, biorenewable aromatic/aliphatic polyester having the general formula H-[O-(CH2)n-O-4-(3-X, 5-Y-C6H2)-CO]z-OH. These are synthesized from the lignin-derived aromatics 4-hydroxybenzoic acid (X?=?Y?=?H), vanillic acid (X?=?OMe; Y?=?H), and syringic acid (X?=?Y?=?OMe). Alkylation of these with several chloroalkanols affords hydroxy-acid monomers suitable for polyesterification under dynamic vacuum between 150 and 250?°C with 1?mol% Sb2O3 as catalyst. Thus, polyalkylene 4-hydroxybenzoates, polyalkylene vanillates, and polyalkylene syringates are prepared, characterized, and subjected to thermal property comparisons by differential scanning calorimetry and thermogravimetric analysis. PMID:21800392

  13. Biodegradable polyesters containing ibuprofen and naproxen as pendant groups

    PubMed Central

    Rosario-Meléndez, Roselin; Yu, Weiling; Uhrich, Kathryn E.

    2013-01-01

    Controlled release of non-steroidal anti-inflammatory drugs such as ibuprofen and naproxen could be beneficial for the treatment of inflammatory diseases while reducing the side effects resulting from their continuous use. Novel biodegradable polyesters solely comprised of biocompatible components (e.g., tartaric acid, 1,8-octanediol, and ibuprofen or naproxen as pendant groups) have been synthesized using tin (II) 2-ethylhexanoate as catalyst at 130 °C and subsequently characterized to determine their structures and physicochemical properties. The polymers release the free drug (ibuprofen or naproxen) in vitro in a controlled manner without burst release, unlike the release rates achieved when the drugs are encapsulated in other polymers. These new biomaterials are not cytotoxic towards mouse fibroblasts up to 0.10 mg/mL. The drugs retain their chemical structure following hydrolytic degradation of the polymer, suggesting that bioactivity is preserved. PMID:23957612

  14. Microwave dielectrometry measurements of glass reinforced polyester resins

    SciTech Connect

    Schlegel, J.L.; Wagner, J.W.; Green, R.E. Jr.

    1999-10-01

    This study describes measurements of dielectric constant as a function of glass reinforcement concentration in polyester resins to use as a control parameter for online process monitoring. Microwave interferometers were constructed in the X and V bands at 9.35 and 60 GHz in both homodyne and heterodyne configurations to measure the phase difference associated with the material. This phase difference is then used to calculate the real part of the dielectric constant from the index of refraction at a microwave frequency. The homodyne X and V band measurements yielded a linear between phase difference and glass concentration. Heterodyne V band measurements produced a nonlinear relationship. Further investigation into the microscopic interactions between the reinforcement particle and the polymer resin is necessary to determine how different concentrations affect the bulk macroscopic material properties.

  15. A novel fabrication method of flexible and monolithic 3D microfluidic structures using lamination of SU8 films

    Microsoft Academic Search

    Patrick Abgrall; Christine Lattes; Véronique Conédéra; Xavier Dollat; Stéphane Colin; Anne Marie Gué

    2006-01-01

    The fabrication of three-dimensional (3D) microfluidic networks entirely made of SU-8 with integrated electrodes is reported. The described technology allows the fabrication of uncrosslinked SU-8 dry film on a polyester (PET) sheet and its subsequent lamination to form closed microstructures. Unlike other reported methods, transferred layers are patterned following the bonding step allowing a more accurate and simple alignment between

  16. Dynamic analysis on the thermal and electrical properties of fabrics in the process of moisture absorption and liberation

    Microsoft Academic Search

    Weigang Cui; Xin Wang; Wenbin Li; Weilin Xu

    2009-01-01

    Purpose – The purpose of this paper is to present a dynamic analysis on the thermal and electrical properties of fabrics under wet conditions. Design\\/methodology\\/approach – A purpose-built apparatus is applied to test the thermal and electrical properties of textiles in moisture absorption and liberation process. Relation between temperature and resistance of a cotton\\/polyester double-layer fabric is also analysed. Findings

  17. Engineered Corynebacterium glutamicum as an endotoxin-free platform strain for lactate-based polyester production

    E-print Network

    Brigham, Christopher J.

    The first biosynthetic system for lactate (LA)-based polyesters was previously created in recombinant Escherichia coli (Taguchi et al. 2008). Here, we have begun efforts to upgrade the prototype polymer production system ...

  18. Stress corrosion crack growth in glass\\/polyester composites with surface crack

    Microsoft Academic Search

    A Akdemir; N Tarakcioglu; A Avci

    2001-01-01

    The propagation characteristics of stress corrosion surface cracks and crack growth rates in a range of unidirectional glass\\/polyester composites exposed to 0.6N dilute HCl acid were examined using a fracture mechanics test. Glass\\/polyester composites were produced from continuous rovings using filament winding method. The shallow surface cracks with various a\\/c and a\\/t ratios were machined on the specimens and under

  19. Synthesis and applications of unsaturated polyester resins based on PET waste

    Microsoft Academic Search

    Jinkyung Kim; Dookyo Jeong; Changho Son; Younghee Lee; Eunyong Kim; Il Moon

    2007-01-01

    Three types of unsaturated polyester resins were synthesized from the glycolysis of polyethylene terephthalate (PET) plastic\\u000a waste, considering environment, cost and properties for their applications. These synthesized unsaturated polyester resins\\u000a could be used for various construction processes and materials such as no dig pipelining (NDR-1), pultrusion (PLR-1) and polymer\\u000a concrete (PCR-1). PET was taken from common soft-drink bottles, and ethylene

  20. Mechanical Properties of Composites Based on Low Styrene Emission Polyester Resins for Marine Applications

    Microsoft Academic Search

    Christophe Baley; Y. Perrot; Peter Davies; A. Bourmaud; Yves Grohens

    2006-01-01

    Glass fibre reinforced polyester composites are used extensively for hulls and decks of pleasure boats. Boat-builders must\\u000a optimise manufacturing technology, not only with respect to mechanical properties but also limiting volatile organic compounds\\u000a (VOC) emissions. One way to achieve this is through modified polyester resin formulations such as low styrene content, low\\u000a styrene emission or combinations of these. The resin

  1. Polyester-Based (Bio)degradable Polymers as Environmentally Friendly Materials for Sustainable Development

    PubMed Central

    Rydz, Joanna; Sikorska, Wanda; Kyulavska, Mariya; Christova, Darinka

    2014-01-01

    This review focuses on the polyesters such as polylactide and polyhydroxyalkonoates, as well as polyamides produced from renewable resources, which are currently among the most promising (bio)degradable polymers. Synthetic pathways, favourable properties and utilisation (most important applications) of these attractive polymer families are outlined. Environmental impact and in particular (bio)degradation of aliphatic polyesters, polyamides and related copolymer structures are described in view of the potential applications in various fields. PMID:25551604

  2. Thermal Properties and Morphology of Liquid Crystalline Copolyester and Polyester Elastomer Blends

    Microsoft Academic Search

    Sang-Hee Jang; Min-Ho Jung; Yeong-Soon Gal; Won-Chull Lee

    1997-01-01

    Polyester elastomer (PEL) blends having a hard segment of polyester (PBT), soft segment of polyether (PTMG), and a liquid crystalline copolyester (LCP), poly(benzoate-naphthoate) were prepared with a twin-screw extruder. Test specimens for thermal properties were prepared by injection molding. Rheological properties and morphology were investigated by Instron capillary rheometer (ICR) and scanning electron microscopy (SEM). Thermal properties of the LCP\\/PEL

  3. Expandable graphite systems for phosphorus-containing unsaturated polyesters. I. Enhanced thermal properties and flame retardancy

    Microsoft Academic Search

    Yeng-Fong Shih; Yih-Tyng Wang; Ru-Jong Jeng; Kuo-Min Wei

    2004-01-01

    A series of flame retardant-containing unsaturated polyesters have been developed. The flame retardants include expandable graphite and phosphorous-containing materials (ammonium polyphosphate (APP) and triphenyl phosphate (TPP)). The effects of incorporating different flame retardants into the unsaturated polyesters were investigated by UL-94, DSC, TGA, LOI, MTGA, Py\\/GC\\/MS and adiabatic bomb calorimeter. The results indicate that the flame-retarding effect of APP type

  4. Visualisation of fingermarks and grab impressions on dark fabrics using silver vacuum metal deposition.

    PubMed

    Knighting, Susan; Fraser, Joanna; Sturrock, Keith; Deacon, Paul; Bleay, Stephen; Bremner, David H

    2013-09-01

    Vacuum metal deposition (VMD) involves the thermal evaporation of metal (silver) in a vacuum, resulting in a uniform layer being deposited on the specimen being treated. This paper examines the use of silver on dark fabrics, thus offering a simpler operation and more obvious colouration to that of the traditional use of gold and zinc metals which must be evaporated separately. The aim of this study was to investigate the effect of fabric type, donor, mark age and method of fingermark deposition on the quality of marks visualised using silver VMD. This was achieved by collecting fingermark deposits from fifteen donors, of both sexes and various ages, by a grab or a press method. Four different fabrics: satin, polyester, polycotton and cotton were studied over a 10day timeline of 1, 2, 3, 4, 5, 6, 7, 14, 21 and 28+ days. It was found that satin and polyester gave the most positive results, with polyester often producing excellent ridge detail. Cotton and polycotton were less successful with no ridge detail being observed. The donors also had an observable effect on the results obtained probably due to variations in secretions produced or pressures applied during specimen collection. The age of the mark or the method of mark deposition had little influence on the results obtained. Silver VMD is a viable process for visualising marks on certain dark fabrics and has the advantage over gold/zinc VMD in that the marks visualised are light in colour which contrasts well against the dark background. PMID:23937939

  5. Surface Modification of PET Fabric by Graft Copolymerization with Acrylic Acid and Its Antibacterial Properties

    PubMed Central

    Abdolahifard, M.; Bahrami, S. Hajir; Malek, R. M. A.

    2011-01-01

    Graft copolymerization of acrylic acid (AA) onto Poly(ethylene terephthalate) (PET) fabrics with the aid of benzoyl peroxide was carried out. The effect of polymerization parameters on the graft yield was studied. Percent grafting was enhanced significantly by increasing benzoyl peroxide (BP) concentrations up to 3.84?g/lit and then decreased upon further increase in initiator concentration. Preswelling of PET leads to changes in its sorption-diffusion properties and favors an increase in the degree of grafting. The antibiotics treated grafted fabrics showed antibacterial properties towards gram-positive and gram-negative microorganisms. FTIR and SEM were used to characterize AA-grafted polyester fabrics. PMID:24052819

  6. Adsorption of active ingredients of surface disinfectants depends on the type of fabric used for surface treatment.

    PubMed

    Bloss, R; Meyer, S; Kampf, G

    2010-05-01

    The disinfection of surfaces in the immediate surrounding of a hospitalised patient is considered to be an important element for prevention of nosocomial infection. The type of fabric in a mop, however, has to our knowledge never been regarded as relevant for an effective disinfection of surfaces. We have therefore studied the adsorption of benzalkonium chloride (BAC), glutardialdehyde and propan-1-ol from working solutions of three surface disinfectants to four different types of fabric (A: white pulp and polyester; B: viscose rayon; C: polyester; D: mixture of viscose, cellulose and polyester). The working solutions of each disinfectant were exposed to each fabric for up to 24h. Before and after exposure, tissues were removed and squeezed in a standardised way. The eluate was used for determination of the concentration of the active ingredient in quadruplicate. The analysis of glutardialdehyde and BAC was performed using high performance liquid chromatography; the analysis of propan-1-ol was done using gas chromatography. BAC was strongly adsorbed to the tissues based on white pulp (up to 61% after 30 min), followed by the viscose rayon tissues (up to 70% after 30 min) and the mixed tissues (up to 54% after 7h). The polyester fibre tissue adsorbed the smallest amounts of BAC with up to 17% after 15 min. Only with the polyester fibre tissue were BAC concentrations found in the range of the calculated BAC concentrations. Glutardialdehyde and propan-1-ol did not adsorb to any of the fibres. Effective surface disinfection also includes selection of an appropriate fabric. PMID:20299122

  7. Novel AC and DC Non-Thermal Plasma Sources for Cold Surface Treatment of Polymer Films and Fabrics at Atmospheric Pressure

    Microsoft Academic Search

    Yuri Akishev; Michail Grushin; Anatoly Napartovich; Nikolay Trushkin

    2002-01-01

    Novel types of non-thermal plasma sources at atmospheric pressure based on multi-pin DC (direct current) diffusive glow discharge and AC (alternative current) streamer barrier corona have been elaborated and tested successfully for cold surface treatment of polymer films [polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET),] and polyester fabric. Results on physical properties ofdischarges mentioned and output energy characteristics of new

  8. Effects of two kinds of clothing made from hydrophobic and hydrophilic fabrics on local sweating rates at an ambient temperature of 37°C

    Microsoft Academic Search

    MINJA HA; HIROMI TOKURA; YUKA YAMASHITA

    1995-01-01

    The purpose of this study was to find the effects of clothing made from hydrophobic and hydrophilic fabrics on the sweating physiology in environmental conditions where only the mechanisms of wet heat loss could occur. A comparison was made of the local sweat rates from the forearm and their related physiological parameters between polyester (E) and cotton (C) clothing at

  9. Bioengineering of bacteria to assemble custom-made polyester affinity resins.

    PubMed

    Hay, Iain D; Du, Jinping; Burr, Natalie; Rehm, Bernd H A

    2015-01-01

    Proof of concept for the in vivo bacterial production of a polyester resin displaying various customizable affinity protein binding domains is provided. This was achieved by engineering various protein binding domains into a bacterial polyester-synthesizing enzyme. Affinity binding domains based on various structural folds and derived from molecular libraries were used to demonstrate the potential of this technique. Designed ankyrin repeat proteins (DARPins), engineered OB-fold domains (OBodies), and VHH domains from camelid antibodies (nanobodies) were employed. The respective resins were produced in a single bacterial fermentation step, and a simple purification protocol was developed. Purified resins were suitable for most lab-scale affinity chromatography purposes. All of the affinity domains tested produced polyester beads with specific affinity for the target protein. The binding capacity of these affinity resins ranged from 90 to 600 nmol of protein per wet gram of polyester affinity resin, enabling purification of a recombinant protein target from a complex bacterial cell lysate up to a purity level of 96% in one step. The polyester resin was efficiently produced by conventional lab-scale shake flask fermentation, resulting in bacteria accumulating up to 55% of their cellular dry weight as polyester. A further proof of concept demonstrating the practicality of this technique was obtained through the intracellular coproduction of a specific affinity resin and its target. This enables in vivo binding and purification of the coproduced "target protein." Overall, this study provides evidence for the use of molecular engineering of polyester synthases toward the microbial production of specific bioseparation resins implementing previously selected binding domains. PMID:25344238

  10. Preparation of rich handles soft cellulosic fabric using amino silicone based softener. Part-I: Surface smoothness and softness properties.

    PubMed

    Zia, Khalid Mahmood; Tabassum, Shazia; Barkaat-ul-Hasin, Syed; Zuber, Mohammad; Jamil, Tahir; Jamal, Muhammad Asghar

    2011-04-01

    A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed onto the surfaces of cotton and blends of cotton/polyester fabrics. Factors affecting the performance properties of the finished substrate such as post-treatment with amino functional silicone based softener varying different emulsifiers in their formulations and its concentration on different processed fabrics were studied. Fixation of the amino-functional silicone softener onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing both the extent of crosslinking and networking as well as providing very high softness. The results of the experiments indicate that the amino silicone can form a hydrophobic film on both cotton and blends of cotton/polyester fabrics and its coating reduces the surface roughness significantly. Furthermore, the roughness becomes lesser with an increase in the applied strength of amino silicone based softener. PMID:21255604

  11. Nanoemulsions and nonwoven fabrics carrying AgNPs: antibacterial but may be cytotoxic.

    PubMed

    Moghtader, Farzaneh; Salouti, Mojtaba; Türk, Mustafa; Pi?kin, Erhan

    2014-12-01

    Abstract The aim of this study is to prepare nonwoven fabrics carrying silver nanoparticles (AgNPs), and to investigate their antibacterial activities and cytotoxicities in parallel. AgNPs were impregnated from their nanoemulsions onto two commercially available nonwoven fabrics: pure-cotton fabrics (PCF) and polyester/viscous fabrics (PVF), by a simple adsorption (dipping) and were then heat stabilized. PCF exhibited stronger antibacterial effects on both Staphylococcus aureus and Escherichia coli. In-vitro cell culture studies demonstrated that AgNPs nanoemulsions and also fabrics carrying them were cytotoxic on L929-fibroblasts in all concentrations used here (6.25-400 ppm) in different extends. Only the fabrics loaded with AgNPs using nanoemulsion with the lowest concentration of 6.25 ppm exhibited low cytotoxicity but were still antibacterial. PMID:24127997

  12. Tearing resistance of some co-polyester sheets

    SciTech Connect

    Kim, Ho Sung; Karger-Kocsis, Jozsef

    2004-06-07

    A three-zone model consisting of initial, evolutionary and stabilised plastic zones for tearing resistance was proposed for polymer sheets. An analysis with the model, based on the essential work of fracture (EWF) approach, was demonstrated to be capable for predicting specific total work of fracture along the tear path across all the plastic zones although accuracy of specific essential work of fracture is subject to improvement. Photo-elastic images were used for identification of plastic deformation sizes and profiles. Fracture mode change during loading was described in relation with the three zones. Tearing fracture behaviour of extruded mono- and bi-layer sheets of different types of amorphous co-polyesters and different thicknesses was investigated. Thick material exhibited higher specific total work of tear fracture than thin mono-layer sheet in the case of amorphous polyethylene terephthalate (PET). This finding was explained in terms of plastic zone size formed along the tear path, i.e., thick material underwent larger plastic deformation than thin material. When PET and polyethylene terephthalate glycol (PETG) were laminated with each other, specific total work of fracture of the bi-layer sheets was not noticeably improved over that of the constituent materials.

  13. Sucrose polyester and plasma carotenoid concentrations in healthy subjects.

    PubMed

    Weststrate, J A; van het Hof, K H

    1995-09-01

    A double-blind, placebo-controlled crossover study of the effects of the nonabsorbable fat analogue sucrose polyester (SPE; 12.4 g/d) on plasma concentrations of five different carotenoids and vitamin E in 21 volunteers, and a double-blind, placebo-controlled parallel comparison study in 53 subjects of the effect of 3 g SPE/d on plasma concentrations of two different carotenoids were undertaken. SPE-containing margarine added to the main meal was used. SPE (12.4 g/d) reduced plasma of beta-carotene concentrations by 0.13 mumol/L (34%, P = 0.0001) and concentrations of lycopene by 0.14 mumol/L (52%, P = 0.0001). Smaller but significant reductions were found for plasma concentrations of beta-cryptoxanthin, lutein, zeaxanthin, and vitamin E. SPE (3 g/d) reduced plasma concentrations of beta-carotene by 0.094 mumol/L (20% P = 0.0001) and concentrations of lycopene by 0.12 mumol/L (38%, P = 0.0001). Even at low doses, SPE strongly reduces plasma carotenoid concentrations. This finding merits careful consideration in assessing the long-term health effects of SPE-containing consumer foods. PMID:7661121

  14. Viscoelastic properties of kenaf reinforced unsaturated polyester composites

    NASA Astrophysics Data System (ADS)

    Osman, Ekhlas A.; Mutasher, Saad A.

    2014-03-01

    In order to quantify the effect of temperature on the mechanical and dynamic properties of kenaf fiber unsaturated polyester composites, formulations containing 10 wt.% to 40 wt.% kenaf fiber were produced and tested at two representative temperatures of 30°C and 50°C. Dynamic mechanical analysis was performed, to obtain the strain and creep compliance for kenaf composites at various styrene concentrations. It is possible to obtain creep curves at different temperature levels which can be shifted along the time axis to generate a single curve known as a master curve. This technique is known as the time-temperature superposition principle. Shift factors conformed to a William-Landel-Ferry (WLF) equation. However, more long term creep data was needed in order to further validate the applicability of time-temperature superposition principle (TTSP) to this material. The primary creep strain model was fitted to 60 min creep data. The resulting equation was then extrapolated to 5.5 days; the creep strain model of power-law was successfully used to predict the long-term creep behavior of natural fiber/thermoset composites.

  15. Resource conservation through beverage-container recycling. [Polyester (PET) bottles

    SciTech Connect

    Gaines, L.L.; Wolsky, A.M.

    1982-01-01

    Since the introduction of plastic soft-drink bottles in 1977, the 2 liter container has captured almost the entire US market. The number of PET (polyethylene terephthalate, a polyester) bottles used in 1981 was 2.4 billion, and could grow to 14 billion by 1990 if the penetration into the 1/2 liter market is as rapid as some experts predict. Consumers value the PET bottle's light weight and unbreakability. However, plastic bottles are made from oil and gas feedstocks which are imported and becoming more expensive. Recycling drastically reduces the oil and gas required to supply these bottles; recycling PET from bottles to other uses could save on the order of 6 million barrels of oil equivalent per year by 1990. A simple and economic technology is available for performing this recovery yet only 5% of the bottles used in 1980 were returned. What is missing is an effective inducement for bottle return. The reverse-vending machines that are proposed can provide part of that inducement by eliminating the inconvenience that now surrounds the sale of empty bottles to recyclers. These machines would dispense coins in return for empty PET bottles, and these machines could be located in supermarkets or their parking lots. It is believed that the design, construction, and use of such machines is an opportunity that has been overlooked.

  16. Modeling of hyperbranched polyesters as hosts for the multifunctional bioactive agent Shikonin.

    PubMed

    Tanis, I; Karatasos, K; Assimopoulou, A N; Papageorgiou, V P

    2011-06-14

    We employ fully atomistic molecular dynamics simulations to study in detail the mechanisms involved in the non-covalent association of the bioactive agent Shikonin with the commercially available hyperbranched polyesters (Boltorn®), in ethanol solutions. We examine effects of the (pseudo)generation of the hyperbranched polyester and mimic two different concentrations, under conditions corresponding to excess drug availability. The two mechanisms participating in the polymer/drug complexation are hydrogen bonding and spatial constriction of the drug molecules within the hyperbranched structure. Based on static, as well as on dynamic information obtained by the analysis performed, it is demonstrated that apart from the size of the polyester, factors like the degree of structural flexibility, the intrapolymer hydrogen bonding and the polymer concentration may affect decisively the polyester/shikonin associative behavior, as well as the behavior of the drug-molecules in the solution. The results from the present study offer a detailed picture of the relative importance of those parameters affecting the complexation, and may serve as a basis for the understanding of the behavior of more complex multi-polyester systems. PMID:21552640

  17. Evaluating the effects of crystallinity in new biocompatible polyester nanocarriers on drug release behavior

    PubMed Central

    Karavelidis, Vassilios; Karavas, Evangelos; Giliopoulos, Dimitrios; Papadimitriou, Sofia; Bikiaris, Dimitrios

    2011-01-01

    Four new polyesters based on 1,3-propanediol and different aliphatic dicarboxylic acids were used to prepare ropinirole HCl-loaded nanoparticles. The novelty of this study lies in the use of polyesters with similar melting points but different degrees of crystallinity, varying from 29.8% to 67.5%, as drug nanocarriers. Based on their toxicity to human umbilical vein endothelial cells, these aliphatic polyesters were found to have cytotoxicity similar to that of polylactic acid and so may be considered as prominent drug nanocarriers. Drug encapsulation in polyesters was performed via an emulsification/solvent evaporation method. The mean particle size of drug-loaded nanoparticles was 164–228 nm, and the drug loading content was 16%–23%. Wide angle X-ray diffraction patterns showed that ropinirole HCl existed in an amorphous state within the nanoparticle polymer matrices. Drug release diagrams revealed a burst effect for ropinirole HCl in the first 6 hours, probably due to release of drug located on the nanoparticle surface, followed by slower release. The degree of crystallinity of the host polymer matrix seemed to be an important parameter, because higher drug release rates were observed in polyesters with a low degree of crystallinity. PMID:22162659

  18. Effect of X-ray irradiation on the structure, thermal and mechanical properties of polyester

    NASA Astrophysics Data System (ADS)

    Nouh, Samir A.; El-Nabarawy, Huda A.; Abutalib, M. M.; Bahareth, Radiyah A.

    2013-06-01

    Samples from sheets of the polymeric material polyester have been exposed to X-rays from a 50 kV X-ray tube in the dose range 10-100 kGy. The resultant effect of X-rays has been investigated using different techniques such as X-ray diffraction XRD, thermogravimetric analysis TGA, differential thermal analysis DTA and stress-strain measurements. The results indicate that the polyester decomposes in one weight loss stage. Also, the X-ray irradiation in the dose range 30-100 kGy led to a more compact structure of polyester, which resulted in an improvement in its thermal stability. The variation of transition temperatures with the X-ray dose has been determined using DTA. The polyester thermograms were characterized by the appearance of an endothermic peak due to the melting of the crystalline phase. The melting temperature of the polymer Tm was investigated to probe the crystalline domains of the polymer. At the dose range 30-100 kGy, the defect generated destroys the crystalline structure, thus reducing the melting temperature. In addition, the stress-strain measurements indicate that the X-ray irradiation at the same dose range 30-100 kGy yields crosslinked polyester of high resilience that is suitable for manufacturing protective clothes that reduce heat stress.

  19. Crease recovery, mechanical and thermal properties of synthetic fabrics treated with electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Zohdy, M. H.; Mohamed, S. S.; El-Naggar, Abdel Wahab M.

    2004-07-01

    The effect of surface treatment of polyester, nylon-6 and cotton/polyester fabrics, with formulations based on polydimethylsiloxane (PDMS) followed by electron beam irradiation, on the crease recovery, mechanical and thermal properties was investigated. The non-reactive siloxane was activated with styrene (S) or methyl methacrylate (MMA) monomers and their corresponding oligomers. The crease recovery properties were determined in terms of the recovery angles in the dry and wet states, while the thermal stability was evaluated by thermogravimetric analysis (TGA) technique. The results showed that the application of MMA/PDMS formulation to the different fabrics improved the crease recovery properties to levels higher than in the case of S/PDMS one. Electron beam surface treatment with S/PDME formulation causes an improvement in tensile mechanical properties, while when MMA/PDMS formulation was applied under the same condition, an opposite trends were observed. The TGA thermograms indicated that electron surface treatment with styrene or MMA formulation has no effect on the thermal stability of polyester, while the treatment with styrene and MMA formulation causes a decrease in the thermal stability of nylon-6 and cotton fabrics within the range 300-450 °C. According to the Tmax of the rate of reaction gives further supports to this finding.

  20. Fabrication of compound nonwoven materials for soft body armor.

    PubMed

    Lin, Chia-Chang; Lin, Jia-Horng; Chang, Chun-Cheng

    2011-09-01

    The primary objective of body armor research is the development of low-cost, lightweight, wearable garments that effectively resist ballistic impact. This study introduces a material intended to reduce nonpenetration trauma by absorbing energy from ballistic impacts. Layers of web were made by low-melting point polyester (LMPET) on unaligned fibers of high-strength polyamide 6 (HSPA6). A compound nonwoven fabric was made by laying high-strength Vectran filaments between two layers of HSPA6-LMPET web. The new fabric underwent needle punching and thermal bonding to form a composite sandwich structure. The new fabric was subjected to a falling weight impact test and a ballistic impact test. The results indicated that the material with the new design reduced maximum indentation depth by 8%. Furthermore, soft body armor made from the material with the new design would cost less to produce and would weigh 22.5% less than conventional soft body armor. PMID:21777238

  1. Physical and thermal properties of UV curable waterborne polyurethane dispersions incorporating hyperbranched aliphatic polyester of varying generation number

    Microsoft Academic Search

    Anila Asif; Wenfang Shi; Xiaofeng Shen; Kangming Nie

    2005-01-01

    Three series of novel waterborne hyperbranched polyurethane acrylates for UV curable aqueous dispersions (WHPUD) based on hydroxy-functionalized hyperbranched aliphatic polyesters Boltorn™ of varying generation number were investigated. The effects of the overall composition, including acidic and acrylate groups, and functionality of hyperbranched polyester were studied in terms of particle size, rheology, photopolymerization kinetics, dynamic mechanical thermal as well as thermal

  2. Fabric Test

    NSDL National Science Digital Library

    In this classroom activity, students work in groups to test a variety of fabrics to determine each one's effectiveness as an insulator. The printable five-page handout includes a series of inquiry-based questions to get students thinking about the conditions in Antarctica and the properties of specialty fabrics, illustrated activity directions and a worksheet that includes areas for recording their experiment data, and questions that prompt students to compare their results against their original hypotheses.

  3. Ring-opening copolymerization (ROCOP): synthesis and properties of polyesters and polycarbonates.

    PubMed

    Paul, Shyeni; Zhu, Yunqing; Romain, Charles; Brooks, Rachel; Saini, Prabhjot K; Williams, Charlotte K

    2015-04-18

    Controlled routes to prepare polyesters and polycarbonates are of interest due to the widespread application of these materials and the opportunities provided to prepare new copolymers. Furthermore, ring-opening copolymerization may enable new poly(ester-carbonate) materials to be prepared which are inaccessible using alternative polymerizations. This review highlights recent advances in the ring-opening copolymerization catalysis, using epoxides coupled with anhydrides or CO2, to produce polyesters and polycarbonates. In particular, the structures and performances of various homogeneous catalysts are presented for the epoxide-anhydride copolymerization. The properties of the resultant polyesters and polycarbonates are presented and future opportunities highlighted for developments of both the materials and catalysts. PMID:25688813

  4. OGP functionalized phenylalanine-based poly(ester urea) for enhancing osteoinductive potential of human mesenchymal stem cells.

    PubMed

    Policastro, Gina M; Lin, Fei; Smith Callahan, Laura A; Esterle, Andrew; Graham, Matthew; Sloan Stakleff, Kimberly; Becker, Matthew L

    2015-04-13

    Amino acid-based poly(ester urea)s (PEU) are high modulus, resorbable polymers with many potential uses, including the surgical repair of bone defects. In vitro and in vivo studies have previously shown that phenylalanine-based PEUs have nontoxic hydrolytic byproducts and tunable degradation times. Phenylalanine PEUs (poly(1-PHE-6)) have been further modified by tethering osteogenic growth peptide (OGP) to tyrosine-based monomer subunits. These OGP-tethered PEUs have been fabricated into porous scaffolds and cultured in vitro to examine their effect on differentiation of human mesenchymal stem cells (hMSCs) toward the osteogenic lineage. The influence of tethered OGP on the hMSC proliferation and differentiation profile was measured using immunohistochemistry, biochemistry, and quantitative real time polymerase chain reaction (qRT-PCR). In vitro data indicated an enhanced expression of BSP by 130-160% for hMSCs on OGP-tethered scaffolds compared to controls. By 4 weeks, there was a significant drop (60-85% decrease) in BSP expression on OGP-functionalized scaffolds, which is characteristic of osteogenic differentiation. ALP and OSC expression was significantly enhanced for OGP-functionalized scaffolds by week 4, with values reaching 145% and 300% greater, respectively, compared to nonfunctionalized controls. In vivo subcutaneous implantation of poly(1-PHE-6) scaffolds revealed significant tissue-scaffold integration, as well as the promotion of both osteogenesis and angiogenesis. PMID:25742124

  5. Superwetting double-layer polyester materials for effective removal of both insoluble oils and soluble dyes in water.

    PubMed

    Li, Bucheng; Wu, Lei; Li, Lingxiao; Seeger, Stefan; Zhang, Junping; Wang, Aiqin

    2014-07-23

    Inspired by the mussel adhesive protein and the lotus leaf, Ag-based double-layer polyester (DL-PET) textiles were fabricated for effective removal of organic pollutants in water. The DL-PET textiles are composed of a top superamphiphilic layer and a bottom superhydrophobic/superoleophilic layer. First, the PET textiles were modified with a layer of polydopamine (PDA) and deposited with Ag nanoparticles to form the PET@PDA@Ag textiles. The top superamphiphilic layer, formed by immobilizing Ag3PO4 nanoparticles on the PET@PDA@Ag textile, shows excellent visible-light photocatalytic activity. The bottom superhydrophobic/superoleophilic layer, formed by modifying the PET@PDA@Ag textile using dodecyl mercaptan, is mechanically, environmentally, and chemically very stable. The water-insoluble oils with low surface tension can penetrate both layers of the DL-PET textiles, while the water with soluble organic dyes can only selectively wet the top layer owing to their unique wettability. Consequently, the water-soluble organic contaminants in the collected water can be decomposed by the Ag3PO4 nanoparticles of the top layer under visible-light irradiation or even sunlight in room conditions. Thus, the DL-PET textiles can remove various kinds of organic pollutants in water including both insoluble oils and soluble dyes. The DL-PET textiles feature unique wettability, high oil/water separation efficiency, and visible-light photocatalytic activity. PMID:24956183

  6. Simulation of Stress-Strain Curves of Polyester and Viscose Filaments

    NASA Astrophysics Data System (ADS)

    Ghosh, Anindya; Das, Subhasis; Saha, Bapi

    2014-11-01

    Eyring's non-linear visco-elastic model has been used to simulate stress-strain behaviours of polyester and viscose filaments. The complex mathematical equations of Eyring's model for curve fitting are handled by non-traditional optimization methods such as genetic algorithm. The findings show that Eyring's model can be used to simulate the stress-strain behaviours of the polyester and viscose filaments with reasonable degree of accuracy. It can also decipher the underlying molecular mechanism of the stress-strain behaviours.

  7. Experimental Investigation on Thermal Physical Properties of an Advanced Polyester Material

    NASA Astrophysics Data System (ADS)

    Guangfa, Gao; Shujie, Yuan; Ruiyuan, Huang; Yongchi, Li

    Polyester materials were applied widely in aircraft and space vehicles engineering. Aimed to an advanced polyester material, a series of experiments for thermal physical properties of this material were conducted, and the corresponding performance curves were obtained through statistic analyzing. The experimental results showed good consistency. And then the thermal physical parameters such as thermal expansion coefficient, engineering specific heat and sublimation heat were solved and calculated. This investigation provides an important foundation for the further research on the heat resistance and thermodynamic performance of this material.

  8. Structure development of polyesters and their blends in film formation processes

    NASA Astrophysics Data System (ADS)

    Song, Kwangjin

    A fundamental study of structure development in cast, single and double bubble, and biaxial film stretching processes of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and PBT/PET blends was carried out. The deformation mechanisms and physical properties of films were described in terms of various structural parameters. We established a new process technique to fabricate double bubble biaxially orientated films from rapidly crystallizing polymers. Polyesters were largely stable in various film forming processes. In film casting, the rate of crystallization tended to dominate the processability of materials. The stability of first bubble was substantially improved with an increase in molecular rigidity. In cold-drawing processes, the stability was dominated by the strain hardening behavior of materials. PBT cast and first bubble films were semicrystalline with only the alpha phase. Cold-drawn films revealed Xsb{c}'s of 20-30% and polymorphism. The polymer chains increasingly oriented into the film plane with biaxial stretching. PBT biaxial films had a maximum tensile strength of 210 MPa. Cast and first bubble films of PET were largely amorphous. PET films stretched in a rubbery state possessed Xsb{c}'s of 20-35%. PET films exhibited (100) planar orientation with crystallites oriented either to the drawing direction or in the plane of the film. A maximum tensile strength of 400 MPa was obtained. Twin screw melt extruded PBT/PET blends exhibited equilibrium melting point depression. The interaction parameters (chisb{12}) were determined to be negative and composition dependent, ranging from -0.75 to -0.55 at 285sp°C. Cast and first bubble films of PBT/PET blends exhibited decreased Xsb{c} with rising PET content. Cold-drawn blend films possessed a Xsb{c}'s of 20-45%. The orientation in the PBT phase decreased with increasing PET content while that in the PET phase increased. The mechanical properties of the films generally followed the rule of mixtures. PEN cast films were largely amorphous. First bubble films developed a maximum Xsb{c} ? 35% and highly perfected polymorphic structure. Cold-dawn PEN films had only the alpha phase and a maximum Xsb{c} ? 48%. PEN films possessed (110) alpha planar orientation.

  9. Synthesis and application of novel EB curable polyester urethane acrylate modified by linseed oil fatty acid

    NASA Astrophysics Data System (ADS)

    Jun, Li; Xuecheng, Ju; Min, Yi; Jinshan, Wei; Hongfei, Ha

    1999-06-01

    A novel polyester urethane acrylate resin modified by linseed oil fatty acid (LFA) was synthesized and EB curing coating was formulated in this work. When the coating cured by EB radiation on the timber, the cured coating was possessed of good performances.

  10. Synthesis and characterization of multifunctional hyperbranched polyesters as prospective contrast agents for targeted MRI

    Microsoft Academic Search

    Zili Sideratou; Dimitris Tsiourvas; Theodossis Theodossiou; Michael Fardis; Constantinos M. Paleos

    2010-01-01

    Based on a commercially available hyperbranched aliphatic polyester, novel multifunctional gadolinium complexes were prepared bearing protective PEG chains, a folate targeting ligand and EDTA or DTPA chelate moieties. Their relatively high water relaxivity values coupled with biodegradability of the hyperbranched scaffold, folate receptor specificity render these non-toxic dendritic polymers promising candidates for MRI applications.

  11. Compression strength of carbon, glass and Kevlar-49 fibre reinforced polyester resins

    Microsoft Academic Search

    M. R. Piggott; B. Harris

    1980-01-01

    The compression behaviour of a series of polyester resins of various compositions and in different states of cure has been investigated. Their mechanical characteristics having been established, the same range of resins was then used as a matrix material for a series of composites reinforced with carbon, glass and aromatic polyamide fibres. The composites were unidirectionally reinforced, having been manufactured

  12. Mechanical Dynamic Studies of Main Chain Liquid Crystalline Polyesters and Polyethers

    Microsoft Academic Search

    H. A. Schneider; W. Stocker; M. Korn; H. R. Kricheldorf; V. Percec

    1991-01-01

    Mechanical-dynamic investigations of main chain liquid crystalline polyesters and polyethers have revealed, besides the well known influences of mechanical and thermal history, a maximum in the tan ? curve in the low frequency range. This is in opposition to the rheological behaviour of amorphous polymers where the tan ? curve increases in a manner practically inversely proportional to the frequency

  13. Study of Optical and Structure Properties of Polyester (PET) and Copolyester (PETG) Fibers by Interferometry

    Microsoft Academic Search

    K. A. El-Farahaty; A. M. Sadik; A. M. Hezma

    2007-01-01

    In this article results on the influence of drawing on the optical and structure properties of polyester (polyethylene terephthalate) and copolyester (glycol-modified polyethylene terephthalate) (4 wt% of ethylene glycol) fibers are reported. Refractive indices, intrinsic birefringence, mean polarizability per unit volume, optical orientation function, density, volume fraction of crystalline material, weight fraction crystallinity, and volume fraction of amorphous and work per

  14. Mechanical Properties of Short Polyester Fiber-Polyurethane Elastomer Composite with Different Interracial Bonding Agents

    Microsoft Academic Search

    F. Suhara; S. K. N. Kutty; G. B. Nando

    1998-01-01

    Mechanical properties of the short-polyester-fiber-reinforced polyurethane elastomer composite with and without different bonding agents were studied. It was found that the properties depend on the orientation and concentration of fibers. Properties such as tensile strength, modulus, and tear strength increase with the increase of fiber loading, whereas the rate of increase of abrasion loss decreases with fiber loading. The bonding

  15. In vitro studies of degradation and bioactivity of aliphatic polyester composites

    Microsoft Academic Search

    Georgia Chouzouri

    2007-01-01

    In spite of numerous publications on the potential use of combinations of aliphatic polyester composites containing bioactive fillers for bone regeneration, little information exists on the combined in vitro mechanisms involving simultaneously diffusion for polymer degradation and bioactivity through nucleation and growth of apatite in simulated body fluid (SBF) solution. The objective of this study is to contribute to the

  16. THERMAL INSULATION PROPERTIES OF NONWOVEN SEMI-DISPOSABLE BLANKETS FROM RECYCLED POLYESTER/COTTON FIBERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recycled polyester fibers and cotton fibers that require no chemical processing were used to produce a low-cost, semi-durable, nonwoven thermal blanket. Thermal blankets were given carboxylic acid finish to improve structural stability during use and laundering. A Steady-State Heat Flow meter FOX ...

  17. TiO2 and polyvinyl alcohol (PVA) coated polyester filter in bioreactor for wastewater treatment.

    PubMed

    Liu, Lifen; Zhao, Chuanqi; Yang, Fenglin

    2012-04-15

    Prepared by coating TiO(2)/polyvinyl alcohol (PVA) on a low cost polyester filter cloth (22 ?m), a composite membrane (10 ?m pore size) was successfully used in an anoxic/oxic membrane bioreactor (A/O-MBR) for treating a simulate wastewater in removing nitrate/ammonium for water reuse in a polyester fiber production plant. Its permeate flux and the anti-fouling properties against extracellular polymeric substances (EPS) were studied. Comparing with a commercial (0.1 ?m) PVDF (polyvinylidene fluoride) membrane, similar effluent qualities were achieved, meeting the basic COD requirements for reuse. Anti-EPS accumulation, the TiO(2)/PVA Polyester composite membrane had higher sustained permeability and required less frequent cleaning. Its filtration time was 4 times longer when operated at a higher flux than the PVDF membrane. The nano-TiO(2) enhances the interaction between PVA and polyester, forms a more hydrophilic surface, drastically reduces the contact angle with water and reduces EPS fouling. The slow (trans-membrane pressure) TMP rise, loose cake layer, the low filtration resistances, and the EPS, SEM analysis confirmed the advantage of the composite membrane. Potential in lowering the membrane cost, the operation and maintenance cost, and in enhancing MBR waste water treatment efficiency is expected by the use of this new composite membrane. PMID:22325932

  18. Making High Performance Unsaturated Polyester Resins With 2Methyl1,3-Propanediol

    Microsoft Academic Search

    Lau Yang; Mac Puckett

    Unsaturated polyester resins (UPR's) have been made by reaction of 2-methyl-1,3- propanediol (MPDiol) with all three of the common aromatic acids, ortho-, iso-, and terephthalic acid. The use of this unique glycol allows production of polymers with improved strength and elongation and better caustic corrosion resistance than the resins more routinely made from propylene glycol (PG). Additionally, formation of a

  19. Soft Bacterial Polyester-Based Shape Memory Nanocomposites Featuring Reconfigurable Nanostructure

    E-print Network

    Mather, Patrick T.

    Soft Bacterial Polyester-Based Shape Memory Nanocomposites Featuring Reconfigurable Nanostructure; published online 13 December 2011 DOI: 10.1002/polb.23021 ABSTRACT: In this work, a novel soft shape memory excellent shape fixing and recovery. Furthermore, it exhibits soft and elastomeric mechanical properties

  20. Reducing problems of cyclic trimer deposits in supercritical carbon dioxide polyester dyeing machinery

    Microsoft Academic Search

    Gerardo Montero; David Hinks; Jacob Hooker

    2003-01-01

    The present paper describes an alternative procedure for the reduction or elimination of oligomeric polyester residues, in particular the cyclic trimer (CTR), in supercritical fluids (SCFs). Polyethylene terephthalate is the largest, (by volume) man-made synthetic fiber produced in the world owing to its favorable properties, such as durability, strength, stability during heat setting, abrasion resistance, and resistance to sunlight, acids,

  1. Dope-dyed Polyester Fibers from Recycled PET Wastes for Use in Molded Automotive Carpets

    Microsoft Academic Search

    K. Gurudatt; P. De; A. K. Rakshit; M. K. Bardhan

    2005-01-01

    Different techniques used for the mass coloration of polyester fibers are discussed in this article. Dope-dyed fibers have been produced starting from PET bottle wastes. Dope dyeing has been carried out both by the incorporation of pigments during drying before melt extrusion and by masterbatch addition. Fibers produced using different pigments and at different add-ons have been evaluated for color

  2. Viscosity change of unsaturated polyester–alumina-composites using polyethylene glycol alkyl ether based dispersants

    Microsoft Academic Search

    T. Hanemann

    2006-01-01

    The influence of a series of polyethylene glycol alkyl ether based dispersants on the viscosity of unsaturated polyester–alumina-composites has been investigated systematically. A few correlations between the dispersants molecular structure, the used concentration and the related composite flow properties have been found. In general only the addition of small dispersant molecules with a short hydrophilic anchoring group and an extended

  3. Effect of silane coupling agents on mechanical and thermal properties of polyester resin concrete

    Microsoft Academic Search

    P. Mani; A. K. Gupta; S. Krishnamoorthy

    1983-01-01

    Polyester resin-quartzite aggregate composites have been investigated for the effect of two silane coupling agents (?-aminopropyl triethoxy silane and?-methacryloxy propyl trimethoxy silane) on the mechanical and thermal properties. The integral blend additive method of application of the coupling agent was used in the preparation of the samples. Variation of the thermal stability and the compressive strength with the nature and

  4. Effect of Concentration of Mica on Properties of Polyester Thermoplastic Elastomer Composites

    Microsoft Academic Search

    M. S. Sreekanth; V. A. Bambole; S. T. Mhaske; P. A. Mahanwar

    Particulate filled polymer composites are becoming attractive because of their wide applications and low cost. In this study the effects of mica with varying concentration on the mechanical, thermal, electrical, rheological and morphological properties of polyester thermoplastic elastomer (Hytrel ®) was investigated. Composites of Hytrel ® with varying concentrations (viz. 5 to 40 weight %) of mica were prepared by

  5. On the stochastic nature of thermomechanical properties in glass reinforced polyester laminates

    Microsoft Academic Search

    T. P. Philippidis; D. J. Lekou; G. A. Kalogiannakis

    2000-01-01

    The objective of this work is to study the statistical nature of effective thermal expansion coefficients (TECs) in glass reinforced polyester (GRP) laminates. To this end, thermomechanical properties and their stochastic behavior of hand lay-up composite laminates of various stacking sequences are defined by conducting a comprehensive experimental program. An adequate number of experiments is performed for two basic glass

  6. Precast use of polymer concrete using unsaturated polyester resin based on recycled PET waste

    Microsoft Academic Search

    K. S. Rebeiz

    1996-01-01

    The strength properties and behaviour of unreinforced and reinforced polymer concrete (pc) using an unsaturated polyester resin based on recycled polyethylene terephthalate (pet) plastic waste are reported. The results obtained show that resins based on recycled pet can be used to produce good quality pc for precast applications such as utility components, transportation components, machine bases and building components. The

  7. Comparison of storage stability of odorous VOCs in polyester aluminum and polyvinyl fluoride tedlar bags

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole air sampling using containers such as flexible bags or rigid canisters is commonly used to collect samples of volatile organic compounds (VOC) in air. The objective of this study was to compare the stability of polyester aluminum (PEA) and polyvinyl fluoride (PVF, brand name Tedlar®) bags for ...

  8. Sensory characterization of polyester-based bottle material inertness using threshold odour number determination

    Microsoft Academic Search

    Heléne Widén; Gunnar Hall

    2007-01-01

    Refillable polyester bottles, for example polyethylene terephthalate (PET) bottles, are known to interact with chemicals. Aroma compounds from a product can be absorbed by the bottle material, remain after washing and remigrate when the bottle is reused, resulting in off-flavour of the new product. A certified reference material has recently been approved with which the chemical and sensory inertness of

  9. The Effect of a Grooved Hollow in a Fibre on Fabric Moisture and Heat-transport Properties

    Microsoft Academic Search

    M. Matsudaira; Y. Kondo

    1996-01-01

    It is shown that polyester fibres are able to absorb water more easily by making a grooved and\\/or a non-grooved hollow in a fibre. The effect of water absorbency becomes larger with an increase in the ratio of space to polymer in the fibre cross-section if the yarn and fabric structures are the same. The effect is especially large under

  10. Thermo-physiological comfort of a PES fabric with incorporated activated carbon : Part I: preliminary physical analysis

    Microsoft Academic Search

    R. Splendore; F. Dotti; B. Cravello; A. Ferri

    2010-01-01

    Purpose – The purpose of this paper is to evaluate the thermo-physiological comfort of a knitted polyester (PES) fabric which contains activated carbon particles in the back-side. Design\\/methodology\\/approach – According to the manufacturer's intention, the activated carbon particles, added in the PES extrusion process, give permanent attributes to the garment, such as odour resistance, UV protection and evaporative cooling. These

  11. Use of textile dyeing technology to create an infection-resistant functionalized polyester biomaterial.

    PubMed

    Aggarwal, Puja; Sousa, Kerry A; Logerfo, Frank W; Bide, Martin J; Phaneuf, Matthew D

    2010-10-01

    Infection is a major complication when utilizing implantable devices. The purpose of this study was to create a functionalized polyethylene terephthalate (polyester) biomaterial with sustained antimicrobial properties using textile-dyeing technology. Polyester was hydrolyzed via exposure to sodium hydroxide (NaOH) to provide two functional sites within the polymeric backbone. A modified textile dyeing technique known as thermofixation or pad-heating (pad-heat) in conjunction with autoclaving was employed to directly incorporate the fluoroquinolone antibiotic Ciprofloxacin (Cipro) into polyester fibers. Woven polyester segments were placed into various concentrations of boiling NaOH solutions to create carboxylic acid and hydroxyl groups (HYD). The segments were then sprayed (padded) with a 5 mg mL(-1) Cipro solution and dried overnight, followed by exposure to intense heat and autoclaving. Untreated HYD, Cipro-dipped, and pad-heat-treated HYD segments were then washed under stringent conditions. The antimicrobial activity of the each material was determined via zone of inhibition. Untreated HYD controls had no antimicrobial activity at any of the time periods examined. Cipro-dipped HYD segments had no antimicrobial activity after 1 h. In contrast, antimicrobial activity for autoclaved, pad-heat-treated HYD segments persisted for 80 days (length of study). Autoclave usage prior to plating affected antimicrobial activity substantially. Additionally, varying hydrolysis concentrations did not significantly affect overall Cipro release. Thus, Cipro application to HYD polyester via thermofixation resulted in controlled, sustained antibiotic release over an extended period of time. The long-term infection resistance provided by this technique may address major problems of infection from which implantable devices suffer. PMID:20725956

  12. SU-E-T-115: Dose Perturbation Study of Self-Expandable Metal and Polyester Esophageal Stents in Proton Therapy Beams

    SciTech Connect

    Lee, S; Li, Z [University of Florida Proton Therapy Institute, Jacksonville, FL (United States); Jalaj, S; McGaw, C; B K, John; J S, Scolapio; J C, Munoz [Division of Gastoenterology, Department of Medicine, University of Florida, Jacksonville, FL (United States)

    2014-06-01

    Purpose: This work investigates dose perturbations due to Self-expandable metal and polyester esophageal stents undergoing proton radiotherapy for esophageal cancer. Methods: Five commercially available esophageal stents made of nitinol (Evolution, Wallflex and Ultraflex), stainless steel (Z-Stent) and polyester (Polyflex) were tested. Radiochromic film (GafChromic EBT3 film, Ashland, Covington, KY) wrapped around a stent and a 12cc syringe was irradiated with 2CGE (Cobalt Gray Equivalent) of proton beam in a custom fabricated acrylic phantom. An air-hollow syringe simulates the esophagus. Results: The Z-stent created the largest dose perturbations ranges from -14.5% to 6.1% due to the steel composition. The WallFlex, Evolution and Ultraflex stents produced the dose perturbation ranges of (?9.2%?8.6%), (?6.8%?5.7%) and (?6.2%?6.2%), respectively. The PolyFlex stent contains the radiopaque tungsten markers located top, middle and bottom portions. When the focal cold spots induced by the markers were excluded in the analysis, the dose perturbation range was changed from (?11.6%?6.4%) to (?0.6%?5.0%). Conclusion: The magnitude of dose perturbation is related to material of a metallic stent. The non-metallic stent such as PolyFlex shows relatively lower dose perturbation than metallic stents except a radiopaque marker region. Overall Evolution and Ultraflex stent appear to be less dose perturbations. The largest dose perturbations (cold spots) were located at both edges of stents in distal area for the single proton beam irradiation study. The analysis of more than two proton beam which is more typical clinical beam arrangement would be necessary to minimize the doe perturbation effect in proton ratiotherapy.

  13. Drug Delivery Nanocarriers from a Fully Degradable PEG-Conjugated Polyester with a Reduction-Responsive Backbone.

    PubMed

    Yameen, Basit; Vilos, Cristian; Choi, Won Il; Whyte, Andrew; Huang, Jining; Pollit, Lori; Farokhzad, Omid C

    2015-08-01

    The remarkably high intracellular concentration of reducing agents is an excellent endogenous stimulus for designing nanocarriers programmed for intracellular delivery of therapeutic agents. However, despite their excellent biodegradability profiles, aliphatic polyesters that are fully degradable in response to the intracellular reducing environment are rare. Herein, a reduction-responsive drug delivery nanocarrier derived from a linear polyester bearing disulfide bonds is reported. The reduction-responsive polyester is synthesized via a convenient polycondensation process. After conjugation of terminal carboxylic acid groups of polyester to polyethylene glycol (PEG), the resulting polymer self-assembles into nanoparticles that are capable of encapsulating dye and anticancer drug molecules. The reduction-responsive nanoparticles display a fast payload release rate in response to the intracellular reducing environment, which translates into superior anticancer activity towards PC-3 cells. PMID:26177931

  14. Thermal degradation behaviour and kinetic analysis of unsaturated polyester-based composites and IPNs by conventional and modulated thermogravimetric analysis

    Microsoft Academic Search

    Yeng-Fong Shih; Ru-Jong Jeng

    2006-01-01

    The thermal degradation behaviour of epoxy\\/unsaturated polyester based polymer interpenetrating networks (IPNs), and unsaturated polyester containing various flame-retardants have been investigated by TGA and Py\\/GC\\/MS. The kinetic parameters of various polymers were analysed by conventional and modulated thermogravimetric analysis (MTGA) methods. The activation energies of degradation were calculated by the Coats–Redfern and MTGA methods, respectively. The results of both conventional

  15. Studies on the cure reaction and thermal properties of NADIC\\/phthalic anhydride modified unsaturated (epoxy) polyesters

    Microsoft Academic Search

    Marta Worzakowska

    2010-01-01

    The cure reaction of NADIC\\/PA modified unsaturated (epoxy) polyesters with styrene initiated by benzoyl peroxide (BPO) or\\u000a the mixture of benzoyl peroxide\\/tetrahydrophthalic anhydride (BPO\\/THPA) and the thermal properties of obtained styrene copolymers\\u000a have been studied. Based on non-isothermal DSC analysis, it was proved that the course of the cure reaction clearly depended\\u000a on the structure of polyesters as well as

  16. Triaxial Fabrics

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Gentax Corporation's triaxal fabrics are woven from three separate yarn sets whose intersections form equilateral triangles. This type of weave, derived from space shuttle pressure suits, assures practically equal strength in every direction; has essentially no bias, or weak dimension offering greater resistance to tear and shear along with significant weight reduction. Applications of the Triax line include inflatable equipment, life vests, aircraft evacuation slides, helicopter flotation devices, tension structures, safety clothing and sailcloth for boats. Ability to accept compound curvatures with no distortion of the weave configuration makes it useful in manufacturing molded composites.

  17. Mechanical and physical properties of polyester polymer concrete using recycled aggregates from concrete sleepers.

    PubMed

    Carrión, Francisco; Montalbán, Laura; Real, Julia I; Real, Teresa

    2014-01-01

    Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate), and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption) was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%), and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior. PMID:25243213

  18. Mechanical and Physical Properties of Polyester Polymer Concrete Using Recycled Aggregates from Concrete Sleepers

    PubMed Central

    Carrión, Francisco; Montalbán, Laura; Real, Julia I.

    2014-01-01

    Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate), and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption) was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%), and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior. PMID:25243213

  19. Correlation between network mechanical properties and physical properties in polyester-urethane coatings

    SciTech Connect

    Scanlan, J.C.; Webster, D.C.; Crain, A.L. [Eastman Chemical Co., Kingsport, TN (United States)

    1995-12-31

    An experimental design to study the effect of polyester formulation on properties of polyurethane coatings was conducted. The five design variables studied were number average molecular weight, average hydroxyl functionality, and the composition of the acid functional monomers (adipic acid, isophthalic acid, and 1,4-cyclohexanedicarboxylic acid). The polyesters were crosslinked with a multifunctional isocyanate to form polyurethane coating films. Coatings were analyzed by traditional physical methods as well as by dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC). By comparing the crosslink density (XLD) of the coatings and the glass transition temperature (Tg) of the coatings with the coatings physical properties and the design variables, we can resolve the effect of Tg and XLD on the hardness and flexibility of the coatings.

  20. Disperse dyeing of polyester fiber using gemini surfactants containing ammonium cations as auxiliaries

    Microsoft Academic Search

    Tae-Soo Choi; Yoshio Shimizu; Hirofusa Shirai; Kunihiro Hamada

    2001-01-01

    The dyeing behavior of the disperse dye, 1,4-diaminoanthraquinone (1,4-DAA), on polyester fiber in the presence of two cationic gemini surfactants, propanediyl-?,?-bis(dimethyldodecylammonium bromide) (DC3-12) and hexanediyl-?,?-bis(dimethyldodecylammonium bromide) (DC6-12) as auxiliaries, was investigated, and compared with that obtained in the presence of the corresponding conventional surfactant, dodecyltrimethylammonium bromide (C12C1NBr). The dyeing rate in the presence of the gemini surfactants was larger than

  1. Measuring gel content of aromatic polyesters using FTIR spectrophotometry and DSC

    Microsoft Academic Search

    Thitisilp Kijchavengkul; Rafael Auras; Maria Rubino

    2008-01-01

    Aromatic polyesters, such as poly(butylene adipate-co-terephthalate) or PBAT, are susceptible to photodegradation, which causes crosslinking in their molecular structure and results in a final reduction of their mechanical properties. Gel content is one of the methods to quantify the degree of crosslinking, but the current ASTM method has some serious drawbacks, including a time-consuming procedure and the use of dangerous

  2. Kinetic and rheological studies of an unsaturated polyester cured with different catalyst amounts

    Microsoft Academic Search

    K. de la Caba; P. Guerrero; A. Eceiza; I. Mondragon

    1996-01-01

    An unsaturated polyester resin was cured with different catalyst contents. The crosslinking process was followed by static and dynamic viscosimetry and by differential scanning calorimetry (d.s.c.). Activation energies were determined from the gel times obtained by viscosimetry and from the variation in the maximum exotherm temperature obtained by d.s.c. at different heating rates. The existence of a threshold in the

  3. Thermal degradation and fire behaviour of unsaturated polyesters filled with metallic oxides

    Microsoft Academic Search

    Lucie Tibiletti; Claire Longuet; Laurent Ferry; Philippe Coutelen; André Mas; Jean-Jacques Robin; José-Marie Lopez-Cuesta

    2011-01-01

    Nano-alumina and submicron alumina trihydrate particles were incorporated into an unsaturated polyester resin at various loadings. The morphologies of composites showed that only nano-alumina was correctly dispersed. The thermal degradation behaviour of the composites was studied using thermogravimetric analysis and Py-GC\\/MS, while their fire behaviour was investigated using cone calorimeter and pyrolysis combustion flow microcalorimeter. Synergistic effects on thermal stability

  4. Effects of temperature and moisture on the mechanical properties of polyester resin in tension

    Microsoft Academic Search

    O. A. Plushchik; A. N. Aniskevich

    2000-01-01

    The effect of environment on the physical and mechanical properties of composite materials in some cases is determined by\\u000a the environmental sensitivity of the binder. The results of experimental investigation of the deformability and strength of\\u000a polyester resin, widely used as a binder in composites, upon the action of stationary and quasi-stationary loads, temperatures,\\u000a and moisture are presented. The ranges

  5. Test procedures for polyester immobilized salt-containing surrogate mixed wastes

    SciTech Connect

    Biyani, R.K.; Hendrickson, D.W.

    1997-07-18

    These test procedures are written to meet the procedural needs of the Test Plan for immobilization of salt containing surrogate mixed waste using polymer resins, HNF-SD-RE-TP-026 and to ensure adequacy of conduct and collection of samples and data. This testing will demonstrate the use of four different polyester vinyl ester resins in the solidification of surrogate liquid and dry wastes, similar to some mixed wastes generated by DOE operations.

  6. Impact tests on woven-roving E-glass\\/polyester laminates

    Microsoft Academic Search

    L. S Sutherland; C Guedes Soares

    1999-01-01

    Experimental results of low-energy drop-weight impact tests on woven-roving E-glass\\/polyester composites are presented. The effects of specimen thickness, impactor kinetic energy, velocity of impact and laminator are investigated. Damage was observed for all impact energies. The assumption that shear deformation dominates the response gives good agreement with the results. A model assuming a circular delamination area predicts very well the

  7. Formulation and optimization of sucrose polyester physical properties by mixture response surface methodology

    Microsoft Academic Search

    Chwen-Jen Shieh; Casimir C. Akoh; Philip E. Koehler

    1996-01-01

    The physical properties of sucrose polyester (SPE), prepared from different composite blends of fatty acid methyl esters (FAME)\\u000a of safflower oil, palm oil, and peanut oil, were evaluated by mixture response surface methodology. Optimum combinations of\\u000a fatty, acids to achieve specific physical properties of SPE were determined. The SPE most similar in physical properties to\\u000a peanut oil was obtained with

  8. Mechanical Properties and Thermal Conductivity of Typha angustifolia Natural Fiber–Reinforced Polyester Composites

    Microsoft Academic Search

    K. Ramanaiah; A. V. Ratna Prasad; K. Hema Chandra Reddy

    2011-01-01

    Partially biodegradable Typha angustifolia natural fiber–reinforced polyester composites were prepared. The fiber content in the composites was varied from ?18.3% to 35.5% by volume, and the mechanical properties in each case were determined. The thermal conductivity of these composites at 333 K temperature was also determined. The mechanical properties increased with increase in fiber content. Further, the density and thermal conductivity

  9. Synthesis, characterization and biodegradation of functionalized amino acid-based poly(ester amide)s

    Microsoft Academic Search

    Xuan Pang; Chih-Chang Chu

    2010-01-01

    A series of biodegradable functional amino acid-based poly(ester amide)s (PEA-AG) were designed and synthesized by the solution co-polycondensation of amino acid (l-phenylalanine and dl-2-allylglycine) based monomers and dicarboxylic acid based monomers. Pendant carbon–carbon double bonds located in the dl-2-allylglycine were incorporated into these PEA-AGs, and the double bond contents could be adjusted by tuning the feed ratio of l-phenylalanine to

  10. Preparation of polyester\\/gypsum\\/composite using gamma radiation, and its radiation stability

    Microsoft Academic Search

    Zaki Ajji

    2005-01-01

    Composites based on pure gypsum and polyester–styrene resin have been prepared using various doses of gamma radiation. Some physical properties of the prepared composites and the influence of irradiation dose on it have been studied as: compression strength, hardness, thermal decomposition temperature in nitrogen or oxygen, and the change in weight in aqueous solutions with different pH values.The glass transition

  11. Preparation and properties of indium tin oxide films deposited on polyester substrates by reactive evaporation

    Microsoft Academic Search

    Jin Ma; Shu-Ying Li; Jun-qing Zhao; Hong-Lei Ma

    1997-01-01

    Highly transparent conducting indium tin oxide (ITO) films have been prepared on polyester thin film substrate by reactively evaporating metal In-Sn alloy in a system with an oxygen partial pressure of (3?30) × 10?5 Torr and substrate temperatures between 80 and 240°C. The structure and opto-electrical properties of the films depending on the deposition conditions have been investigated. High quality

  12. Small molecule penetrant diffusion in aromatic polyesters: a molecular dynamics simulation study

    Microsoft Academic Search

    Rishikesh K. Bharadwaj; Richard H. Boyd

    1999-01-01

    Molecular dynamics (MD) simulations have been used to study diffusion of methane in three highly impermeable aromatic polyesters that are good barrier materials. These are amorphous poly(ethylene terephthalate) (PET) and poly(ethylene 2,6-naphthalene dicarboxylate) (PEN), and the nematic mesophase of the thermotropic liquid crystalline copolyester (LCP) of p-hydroxy benzoic acid (HBA) and 2,6 hydroxy naphthoic acid (HNA). Diffusion coefficients were determined

  13. Fatigue performance of glass\\/polyester laminates and the monitoring of material degradation

    Microsoft Academic Search

    P. Brøndsted; S. I. Andersen; H. Lilholt

    1996-01-01

    Experiments are performed on glass\\/polyester composites under fatigue loading. The stiffness degradation is recorded as an indirect measure of material damage. The stiffness decrease rate is described by a power dependence on stress; this relationship allows the fatigue law to be derived. Stiffness-controlled fatigue curves are generated and presented in an S-N-diagram based on normalized stress (equivalent to strain). Such

  14. High-strength high-modulus fibres from liquid-crystalline aromatic polyesters

    Microsoft Academic Search

    A. V. Volokhina

    1990-01-01

    Fibre-forming liquid-crystalline (LC) polyesters are a new generation of highly efficient polymers. They were synthesized in the middle of the 70s, that is, approximately ten years after the preparation of LC aromatic polyamides. Industrial manufacture of the latter in the preparation of high-strength fibres based on them, of the Kevlar type, was organized at thc start of the 70s. LC

  15. Isolation and characterization of a bacterium that degrades various polyester-based biodegradable plastics

    Microsoft Academic Search

    T. Teeraphatpornchai; T. Nakajima-Kambe; Y. Shigeno-Akutsu; M. Nakayama; N. Nomura; T. Nakahara; H. Uchiyama

    2003-01-01

    Microorganisms isolated from soil samples were screened for their ability to degrade various biodegradable polyester-based plastics. The most active strain, designated as strain TB-13, was selected as the best strain for degrading these plastics. From its phenotypic and genetic characteristics, strain TB-13 was closely related to Paenibacillus amylolyticus. It could degrade poly(lactic acid), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(caprolactone) and poly(ethylene

  16. Compatible blends of biorelated polyesters through catalytic transesterification in the melt

    Microsoft Academic Search

    Maria-Beatrice Coltelli; Claudio Toncelli; Francesco Ciardelli; Simona Bronco

    2011-01-01

    The transesterification during the melt blending of polylactide (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) was investigated in presence of Ti(OBu)4 as a catalyst. Both the effect of catalyst concentration and reaction duration was considered. The process was studied by analyzing the molecular weight of the polyesters by size exclusion chromatography (SEC). The rheological, thermal and morphological properties of the blends were

  17. Effect of solvents on properties of polymer gel-electrolyte based on polyester diacrylate

    Microsoft Academic Search

    O. V. Yarmolenko; Yu. V. Baskakova; G. Z. Tulibaeva; L. M. Bogdanova; E. A. Dzhavadyan; B. A. Komarov; N. F. Surkov; B. A. Rozenberg; O. N. Efimov

    2009-01-01

    New polymer gel electrolytes based on polyester diacrylates and LiClO4 salt solutions in organic solvents are developed for lithium ion and lithium polymer batteries with a high ionic conductivity\\u000a up to 2.7 × 10?3 Ohm?1cm?1 at the room temperature. To choose the optimum liquid electrolyte composition, the dependence is studied of physico-chemical\\u000a parameters of new gel electrolytes on the composition

  18. Unsaturated polyester resins modified with poly(?-caprolactone)–perfluoropolyethers block copolymers

    Microsoft Academic Search

    M Messori; M Toselli; F Pilati; C Tonelli

    2001-01-01

    Poly(?-caprolactone)–perfluoropolyether–poly(?-caprolactone) block copolymers (TXCL) synthesised from Fomblin Z-DOL TX (TX) have been mixed with conventional unsaturated polyester resins (UPR) to prepare fluorine modified UPR (FUPR). A preliminary investigation on the compatibility of uncured FUPR systems has shown that the presence of PCL blocks leads to an enhancement of compatibility with respect to pure perfluoropolyether macromers. The compatibility tends to decrease

  19. Sulphur-containing polymers: Synthesis and thermal properties of novel polyesters based on dithiotriethylene glycol

    Microsoft Academic Search

    N. Lotti; V. Siracusa; L. Finelli; P. Marchese; A. Munari

    2006-01-01

    Poly(dithiotriethylene terephthalate) (PSSTET), poly(dithiotriethylene adipate) (PSSTEA), poly(triethylene terephthalate) (PTET) and poly(triethylene adipate) (PTEA), these two last for comparison, were synthesized and characterized in terms of chemical structure and molecular weight. The thermal behaviour was examined by thermogravimetric analysis and differential scanning calorimetry. All the polymers showed a good thermal stability, even though lower for the sulphur-containing polyesters. At room temperature

  20. Dielectric Properties of Lead Monoxide Filled Unsaturated Polyester Based Polymer Composites

    NASA Astrophysics Data System (ADS)

    Harish, V.; Kumar, H. G. Harish; Nagaiah, N.

    2011-07-01

    Lead monoxide filled isophthalate resin particulate polymer composites were prepared with different filler concentrations and investigated for physical, thermal, mechanical and gamma radiation shielding characteristics. This paper discusses about the dielectric properties of the composites. The present study showed that the dielectric constant (?'), dielectric loss (??) and ac conductivity (?ac) of isopthalate based unsaturated polyester resin increases with the increase in wt% PbO filler in polymer matrix.

  1. Thermal properties and interactions in blends of poly(?-caprolactone) with unsaturated polyester resins

    Microsoft Academic Search

    D. Nava; C. Salom; M. G. Prolongo; R. M. Masegosa

    2003-01-01

    Blends of two linear unsaturated polyester (LUP, commercially named AL-100 and 6603) with poly(?-caprolactone) (PCL) were prepared by the casting method. Differential scanning calorimetry (DSC) has been used to study the miscibility, melting behaviour and crystallinity of 6603+PCL and AL-100+PCL blends. Two different heat treatments (Method 1 and Method 2), were carried out, in both systems. Only by following Method

  2. Miscibility, mechanical and thermal properties of poly(lactic acid)\\/polyester-diol blends

    Microsoft Academic Search

    Kenzo Okamoto; Tomokazu Ichikawa; Tadashi Yokohara; Masayuki Yamaguchi

    2009-01-01

    We found new plasticizers with high molecular weight and low mobility for poly(lactic acid) (PLA). The new plasticizers are polyester-diols (PED) with nominal molecular weight 2000. Temperature dependence of oscillatory tensile moduli of PLA\\/PED blends in solid states was measured and miscible pairs of the blends were found. The miscible pairs are PLA\\/poly(ethylene adipate) and PLA\\/poly(diethylene adipate). Observation by scanning

  3. Blended Epoxy\\/Polyester Polymer Nanocomposites: Effect of “Nano” on Mechanical Properties

    Microsoft Academic Search

    K. V. P. Chakradhar; K. Venkata Subbaiah; M. Ashok Kumar; G. Ramachandra Reddy

    2012-01-01

    The inter-cross-linked networks of unsaturated polyester (UP) toughened epoxy blends were developed. Montmorillonite (MMT) clay was dispersed into the same system to prepare blended epoxy\\/UP\\/clay nanocomposites in different weight ratios viz. 0%, 1%, 2%, 3% and 5%. Mechanical properties like tensile strength (TS), impact strength (IS) and interlaminar shear strength (ILSS) were characterized for the above nanocomposites. Blended nanocomposites were

  4. Fast degrading polyesters as siRNA nano-carriers for pulmonary gene therapy

    Microsoft Academic Search

    Juliane Nguyen; Terry W. J. Steele; Olivia Merkel; Regina Reul; Thomas Kissel

    2008-01-01

    \\u000aA potential siRNA carrier for pulmonary gene delivery was assessed by encapsulating siRNA into biodegradable polyester nanoparticles consisting of tertiary-amine-modified polyvinyl alcohol (PVA) backbones grafted to poly(d,l-lactide-co-glycolide) (PLGA). The resulting siRNA nanoparticles were prepared using a solvent displacement method that offers the advantage of forming small nanoparticles without using shear forces. The nanoparticles were characterized with regard to particle size,

  5. Fast degrading polyesters as siRNA nano-carriers for pulmonary gene therapy

    Microsoft Academic Search

    Juliane Nguyen; Terry W. J. Steele; Olivia Merkel; Regina Reul; Thomas Kissel

    2008-01-01

    A potential siRNA carrier for pulmonary gene delivery was assessed by encapsulating siRNA into biodegradable polyester nanoparticles consisting of tertiary-amine-modified polyvinyl alcohol (PVA) backbones grafted to poly(d,l-lactide-co-glycolide) (PLGA). The resulting siRNA nanoparticles were prepared using a solvent displacement method that offers the advantage of forming small nanoparticles without using shear forces. The nanoparticles were characterized with regard to particle size,

  6. Potential use of reclaimed propylene glycol in manufacturing unsaturated polyester resins

    SciTech Connect

    Doherty, F.W. [Reichhold Chemicals, Inc., Research Triangle Park, NC (United States)

    1996-11-01

    It seems as if the excitement and concern for using reclaimed materials in the FRP industry has not stabilized to a point at which either suppliers of raw materials and intermediates or the custom molders know exactly how to approach the demands of ``Make it green.`` Definitions of post-industrial and post-consumer are not clear. Support for those who are attempting to use recycled materials is not evident. Economics are in the wrong direction, and, in the FRP industry, development labs are swamped with every scrap someone has picked up before it went to a landfill to see if it can be used as a filler or reinforcement. One area that does need closer consideration is the potential use of reclaimed raw materials for use in manufacturing unsaturated and saturated polyesters. Thermoplastic additive for shrink control should also be considered. Approximately 32% (168 million pounds) of the polyethylene glycol (PG) produced in the US is used for unsaturated polyesters. About 18% is used along with some ethylene glycol (EG) as a functional fluid. About 98 million pounds of that group is for antifreeze products. Assuming normal winters, several million pounds of de-icing fluids could be reclaimed and cooked into unsaturated polyesters with little of the added cost typically associated with recycled materials.

  7. Development and performance optimization of knitted antibacterial materials using polyester-silver nanocomposite fibres.

    PubMed

    Majumdar, Abhijit; Butola, Bhupendra Singh; Thakur, Sandip

    2015-09-01

    The development and performance optimization of knitted antibacterial materials made from polyester-silver nanocomposite fibres have been attempted in this research. Inherently antibacterial polyester-silver nanocomposite fibres were blended with normal polyester fibres in different weight proportions to prepare yarns. Three parameters, namely blend percentage (wt.%) of nanocomposite fibres, yarn count and knitting machine gauge were varied for producing a large number of knitted samples. The knitted materials were tested for antibacterial activity against Gram-positive bacteria Staphylococcus aureus. Statistical analysis revealed that all the three parameters were significant and the blend percentage of nanocomposite fibre was the most dominant factor influencing the antibacterial activity of knitted materials. The antibacterial activity of the developed materials was found to be extremely durable as there was only about 1% loss even after 25 washes. Linear programming approach was used to optimize the parameters, namely antibacterial activity, air permeability and areal density of knitted materials considering cost minimization as the objective. The properties of validation samples were found to be very close to the targeted values. PMID:26046264

  8. Mechanical Properties of Composites Based on Low Styrene Emission Polyester Resins for Marine Applications

    NASA Astrophysics Data System (ADS)

    Baley, Christophe; Perrot, Y.; Davies, Peter; Bourmaud, A.; Grohens, Yves

    2006-01-01

    Glass fibre reinforced polyester composites are used extensively for hulls and decks of pleasure boats. Boat-builders must optimise manufacturing technology, not only with respect to mechanical properties but also limiting volatile organic compounds (VOC) emissions. One way to achieve this is through modified polyester resin formulations such as low styrene content, low styrene emission or combinations of these. The resin matrix selection procedure is based on design specification (mechanical behaviour) but also manufacturing requirements and cost considerations. For this application post-cure is rarely used so it is important to optimise curing conditions. In this study the influence of the curing cycle on mechanical properties was examined first for two polyester resins. Then for one cycle (16 h at 40°C) the properties of eight resins have been determined. Significant differences in failure strain are observed, from 0.9% to 3.3%. The resins with improved VOC performance are the most brittle. The transverse tensile behaviour of these resins in composites with unidirectional glass fibre reinforcement and the limit of linearity for composites with glass mat both depend on these failure strains. These results are discussed in terms of admissible composite strains for boat design.

  9. Azobenzene polyesters used as gate-like scaffolds in nanoscopic hybrid systems.

    PubMed

    Bernardos, Andrea; Mondragón, Laura; Javakhishvili, Irakli; Mas, Núria; de la Torre, Cristina; Martínez-Máñez, Ramón; Sancenón, Félix; Barat, José M; Hvilsted, Søren; Orzaez, Mar; Pérez-Payá, Enríque; Amorós, Pedro

    2012-10-01

    The synthesis and characterisation of new capped silica mesoporous nanoparticles for on-command delivery applications is reported. Functional capped hybrid systems consist of MCM-41 nanoparticles functionalised on the external surface with polyesters bearing azobenzene derivatives and rhodamine?B inside the mesopores. Two solid materials, Rh-PAzo8-S and Rh-PAzo6-S, containing two closely related polymers, PAzo8 and PAzo6, in the pore outlets have been prepared. Materials Rh-PAzo8-S and Rh-PAzo6-S showed an almost zero release in water due to steric hindrance imposed by the presence of anchored bulky polyesters, whereas a large delivery of the cargo was observed in the presence of an esterase enzyme due to the progressive hydrolysis of polyester chains. Moreover, nanoparticles Rh-PAzo8-S and Rh-PAzo6-S were used to study the controlled release of the dye in intracellular media. Nanoparticles were not toxic for HeLa cells and endocytosis-mediated cell internalisation was confirmed by confocal microscopy. Furthermore, the possible use of capped materials as a drug-delivery system was demonstrated by the preparation of a new mesoporous silica nanoparticle functionalised with PAzo6 and loaded with the cytotoxic drug camptothecin (CPT-PAzo6-S). Following cell internalisation and lysosome resident enzyme-dependent gate opening, CPT-PAzo6-S induced CPT-dependent cell death in HeLa cells. PMID:22927363

  10. Conceptual design and comparison of aramid and polyester taut leg spread moorings for deepwater applications

    SciTech Connect

    Wilde, B.; Kelly, P.; Librino, F.; Whitehill, A.S.

    1996-12-31

    As the offshore industry looks beyond water depths of 3,000 ft for future oil and gas production, the industry standard steel catenary spread mooring (CSM) system used on all floating production systems installed to date becomes increasingly inefficient and costly. An alternative to the CSM is the Taut Leg Spread Mooring (TLSM) system with its characteristic short scope legs and vertically loaded anchors. In water depths greater than 3,000 ft, it has been shown that TLSMs comprised of synthetic mooring lines have performance advantages over systems utilizing steel wire rope and demonstrated potential for significant cost reductions. Early studies investigated the use of aramid fiber rope due to its high strength, lower in-water weight and lower axial stiffness as compared to ropes made from steel. Later studies indicated that the material properties of polyester fiber, primarily its lower Young`s modulus, made polyester mooring lines more suitable for use in TLSMs. As the TLSM knowledge base expanded, aramid rope construction evolved. Earlier efforts to match the characteristics of steel wire rope have given way to new generation soft aramid constructions. This paper compares the mooring performance and total installed cost of a soft aramid TLSM to a typical polyester configuration. Both systems were designed for use in the Gulf of Mexico (GOM) with an FPS based on the Aker P45.

  11. Cellular internalization pathway and transcellular transport of pegylated polyester nanoparticles in Caco-2 cells.

    PubMed

    Song, Qingxiang; Wang, Xiaolin; Hu, Quanyin; Huang, Meng; Yao, Lei; Qi, Hong; Qiu, Yu; Jiang, Xinguo; Chen, Jun; Chen, Hongzhuan; Gao, Xiaoling

    2013-03-10

    Biodegradable polyester nanoparticles have now attracted growing interest as promising drug delivery system. However, a fundamental understanding about its cellular transport as well as the influence by the polymeric architecture is still lack, which remains a significant obstacle to optimal nanocarrier design. In this work, using Caco-2 cell model, we characterized the cellular transport pathway of pegylated polyester nanoparticles and determined the effect of polymer architecture including PEG chain length and core material on its cellular interaction and transcellular transport. The nanoparticles were found to undergo an energy-dependent, lipid raft-mediated, but caveolae-independent endocytosis. PEG chain length (from 2000 to 5000 Da) and core material (PLA/PLGA) hardly affected the cellular interaction and the intracellular itinerary of the nanoparticles. However, in the case of transcellular transport, the maximal transcellular transport efficiency for its payload was achieved by the PEG5000-PLA40000 nanoparticles which present higher drug loading capacity and slower drug release. The findings here revealed the cellular interaction mechanism of pegylated polyester nanoparticles and provided evidence for the role of polymer architectures in modulating the transcellular permeability of the agents loaded by the nanoparticles, and would be helpful in improving carrier design to enhance drug delivery. PMID:23380624

  12. Functionalisation of fabrics with conducting polymer for tuning capacitance and fabrication of supercapacitor.

    PubMed

    Firoz Babu, K; Siva Subramanian, S P; Anbu Kulandainathan, M

    2013-04-15

    Conducting polymer (polypyrrole (PPy) doped with anion) film has been coated on different textile substrates from a mild, room temperature wet in situ chemical polymerisation method exploiting pyrrole as a monomer and ferric chloride as an oxidant and compared their electrochemical capacitive behaviour by assembling as an unit cell supercapacitor. PPy composites were prepared with carbohydrate polymers like cotton, linen (Natural cellulosic fibre), modified cellulosic fibre-viscose rayon and synthetic polymer polyester fabrics to investigate the influence on electrochemical capacitance. The surface morphology and chemistry of these materials were analysed by SEM, FT-IR, and XRD. It reveals that the PPy has greater interaction with the cellulosic fabrics, but whereas surface deposition only has taken place with synthetic fibres. The capacitive behaviour of the PPy coated textiles were evaluated using cyclic voltammetry, impedance spectroscopy and charge-discharge analysis. A unit cell was fabricated to investigate the capacitive behaviour by assembling two symmetric textile electrodes separated by a solid polymer (PVA/1M H2SO4 gel) electrolyte membrane. The textile electrodes prepared with PPy-Cotton and PPy-Viscose exhibited the highest specific capacitance value of 268 F g(-1) and 244 F g(-1), respectively at a scan rate of 5 mV s(-1). The charge-discharge analysis also shows higher specific capacitance value for PPy-Viscose and PPy-Cotton. The focus of this research is to highlight a successful, simple and reproducible method for fabrication of the textile based supercapacitor and the chemistry of surface interaction of PPy molecule with natural and synthetic fabrics. PMID:23544566

  13. Improvement of Burning Properties on the Cotton\\/polyester\\/lacra Blend Fabric with Nano Silicone Material in Nano Silicone

    Microsoft Academic Search

    Hossein Najafi

    2009-01-01

    In this research, we established a modified 45 fl ammability test for cotton blend material to measure the flammability of nanosilicone softener treated-cotton blend material. The wet pick-up was about 150±10%. b) The specimens were tested in the cross direction and nine specimens were measured. The average percent weight loss of the untreated cotton blend nonwoven is only 0.9%. The

  14. The impact of nitrogen low temperature plasma treatment upon the physical–chemical properties of polyester fabric

    Microsoft Academic Search

    Mohammad Mirjalili; Loghman Karimi

    2012-01-01

    Thermal properties, light reflection, dye absorption, and resistance against bacteria growth have made fibers and textiles very important and applicable in industry. These are mainly attributed to the structure and the surface characteristics, and their modification appears to be very contribute to improving the properties of textiles. Most of the methods aimed at such modifications are implemented in a liquid

  15. Click synthesis of neutral, cationic, and zwitterionic poly(propargyl glycolide)-co-poly(?-caprolactone)-based aliphatic polyesters as antifouling biomaterials.

    PubMed

    Tu, Qin; Wang, Jian-Chun; Liu, Rui; Chen, Yun; Zhang, Yanrong; Wang, Dong-En; Yuan, Mao-Sen; Xu, Juan; Wang, Jinyi

    2013-08-01

    With the development of polymer-based biomaterials, aliphatic polyesters have attracted considerable interest because of their non-toxicity, non-allergenic property, and good biocompatibility. However, the hydrophobic nature and the lack of side chain functionalities of aliphatic polyesters limit their biomedical applications. In this study, we prepared four new polyesters: poly(sulfobetaine methacrylate)-, poly(2-methacryloyloxyethyl phosphotidylcholine)-, poly(ethylene glycol)-, and quaternized poly[(2-dimethylamino)ethyl methacrylate]-grafted poly(propargyl glycolide)-co-poly(?-caprolactone). Their synthesis was conducted through ring-opening polymerization of acetylene-functionalized lactones and subsequent graft of bioactive units using click chemistry. The chemical structures of the polyesters were characterized through nuclear magnetic resonance and Fourier-transform infrared spectroscopy, and their physical properties (including molecular weight, glass transition temperature, and melting point) were determined using gel permeation chromatography and differential scanning calorimetry. For studies on their hydrophilicity, stability, and anti-bioadhesive property, a series of polymeric surfaces of these polyesters was prepared by coating them onto glass substrates. The hydrophilicity and stability of these polyester surfaces were examined by contact angle measurements and attenuated total reflection Fourier-transform infrared spectroscopy. Their anti-bioadhesive property was investigated through protein adsorption, as well as cellular and bacterial adhesion assays. The prepared polyesters showed good hydrophilicity and long-lasting stability, as well as significant anti-fouling property. The newly prepared polyesters could be developed as promising anti-fouling materials with extensive biomedical applications. PMID:23511626

  16. 2. Synthesis and evaluation of novel biodegradable elastomeric polyesters. J. Yang, A. Webb, S. Pickerill, G. Hageman and G.A. Ameer. Biomaterials, In Press 2005

    E-print Network

    Ottino, Julio M.

    2. Synthesis and evaluation of novel biodegradable elastomeric polyesters. J. Yang, A. Webb, S and evaluation of a novel family of biodegradable and elastomeric polyesters, poly(diol citrates). Poly and in vivo evaluation using cell culture and subcutaneous implantation, respectively, confirmed cell

  17. The influence of side-chain and main-chain spacer lengths on the thermal and structural properties of diethanolamine based side-chain polyesters

    Microsoft Academic Search

    M. Huski?; M. Žigon

    2004-01-01

    SummaryA series of linear side-chain aliphatic polyesters have been synthesized from ?-(bis(2-hydroxyethyl)amino)-?-(4’-methoxybiphenyl-4-oxy) alkanes and aliphatic acid chlorides. The side-chain and main-chain spacer lengths were varied and their influences on thermal and structural properties of polyesters, as determined by DSC and X-ray diffraction, are discussed.

  18. In vivo evaluation of hydroxyapatite nanocoating on polyester artificial vascular grafts and possibility as soft-tissue compatible material.

    PubMed

    Kadono, Hiroyuki; Furuzono, Tsutomu; Masuda, Miwa; Okada, Masahiro; Ueki, Mitsuki; Takamizawa, Keiichi; Tanaka, Ryoichi; Miyatake, Kunio; Koyama, Yoshihisa; Takakuda, Kazuo

    2010-01-01

    The efficacy of hydroxyapatite (HAp) nanocoating on polyester vascular grafts was investigated in animal experiments. The HAp nanocrystals were covalently bonded separately between hydroxyl groups on a nanocrystal and alkoxysilyl groups in gamma-methacryloxypropyl triethoxysilane graft polymerized on a polyester substrate. Twelve HAp-coated polyester grafts and 10 control grafts of 20, 30, or 50 mm in length were implanted in canine common carotid arteries. Serious complications or occlusions were not observed in any of the dogs after implantation. A histologic evaluation was conducted by staining with hematoxylin and eosin (HE), the von Willebrand factor (vWf), and alpha-smooth muscle actin (alpha-SMA) around the inner lumen of the grafts. The number of inflammation cells and giant cells in the HAp-coated group was significantly lower than that in the group receiving noncoated grafts (p < 0.05). PMID:20051831

  19. Deep eutectic solvent-assisted synthesis of biodegradable polyesters with antibacterial properties.

    PubMed

    García-Argüelles, Sara; Serrano, M Concepción; Gutiérrez, María C; Ferrer, M Luisa; Yuste, Luis; Rojo, Fernando; del Monte, Francisco

    2013-07-30

    Bacterial infection related to the implantation of medical devices represents a serious clinical complication, with dramatic consequences for many patients. In past decades, numerous attempts have been made to develop materials with antibacterial and/or antifouling properties by the incorporation of antibiotic and/or antiseptic compounds. In this context, deep eutectic solvents (DESs) are acquiring increasing interest not only as efficient carriers of active principle ingredients (APIs) but also as assistant platforms for the synthesis of a wide repertoire of polymer-related materials. Herein, we have successfully prepared biodegradable poly(octanediol-co-citrate) polyesters with acquired antibacterial properties by the DES-assisted incorporation of quaternary ammonium or phosphonium salts into the polymer network. In the resulting polymers, the presence of these salts (i.e., choline chloride, tetraethylammonium bromide, hexadecyltrimethylammonium bromide, and methyltriphenylphosphonium bromide) inhibits bacterial growth in the early postimplantation steps, as tested in cultures of Escherichia coli on solid agar plates. Later, positive polymer cytocompatibility is expected to support cell colonization, as anticipated from in vitro preliminary studies with L929 fibroblasts. Finally, the attractive elastic properties of these polyesters permit matching those of soft tissues such as skin. For all of these reasons, we envisage the utility of some of these antibacterial, biocompatible, and biodegradable polyesters as potential candidates for the preparation of antimicrobial wound dressings. These results further emphasize the enormous versatility of DES-assisted synthesis for the incorporation, in the synthesis step, of a wide palette of APIs into polymeric networks suitable for biomedical applications. PMID:23808373

  20. Clickable degradable aliphatic polyesters via copolymerization with alkyne epoxy esters: synthesis and postfunctionalization with organic dyes.

    PubMed

    Teske, Nele S; Voigt, Julia; Shastri, V Prasad

    2014-07-23

    Degradable aliphatic polyesters are the cornerstones of nanoparticle (NP)-based therapeutics. In this paradigm, covalent modification of the NP with cell-targeting motifs and dyes can aid in guiding the NP to its destination and gaining visual confirmation. Therefore, strategies to impart chemistries along the polymer backbone that are amenable to easy modification, such as 1,3-dipolar cycloaddition of an azide to an alkyne (the "click reaction"), could be significant. Here we present a simple and efficient way to introduce alkyne groups at high density in aliphatic polyesters without compromising their crystallinity via the copolymerization of cyclic lactones with propargyl 3-methylpentenoate oxide (PMPO). Copolymers of lactic acid and ?-caprolactone with PMPO were synthesized with up to 9 mol % alkyne content, and accessibility of the alkyne groups to the click reaction was demonstrated using several dyes commonly employed in fluorescence microscopy and imaging (Cy3, ATTO-740, and coumarin 343). In order to establish the suitability of these copolymers as nanocarriers, copolymers were formulated into NPs, and cytocompatibility, cellular uptake, and visualization studies undertaken in HeLa cells. Dye-modified NPs exhibited no quenching, remained stable in solution for at least 10 days, showed no cytotoxicity, and were readily taken up by HeLa cells. Furthermore, in addition to enabling the incorporation of multiple fluorophores within the same NP through blending of individual dye-modified copolymers, dye-modified polyesters offer advantages over physical entrapment of dye, including improved signal to noise ratio and localization of the fluorescence signal within cells, and possess the necessary prerequisites for drug delivery and imaging. PMID:24972035

  1. Photoinduced anisotropy in a family of amorphous azobenzene polyesters for optical storage

    NASA Astrophysics Data System (ADS)

    Nedelchev, Lian L.; Matharu, Avtar S.; Hvilsted, Søren; Ramanujam, P. S.

    2003-10-01

    We investigate parameters associated with optical data storage in a variety of amorphous side-chain azobenzene-containing polyesters denoted as E1aX. The polyesters possess a common cyano-substituted azobenzene chromophore as a side chain, but differ in their main-chain polyester composition. Seventeen different polymers from the E1aX family divided into four classes, depending on the type of the main-chain substituent (one-, two-, and three-ring aromatic or alicyclic) have been thoroughly investigated. Various parameters characterizing the photoinduced birefringence in these materials, such as the response time, thermal and light stability, and long-term stability under ambient light at room temperature have been measured. Each of these parameters is quantitatively represented and therefore it is possible to make a clear comparison between the properties of the polymers. The results indicate that the long-term stability at ambient temperature is closely related to the thermal stability of the photoinduced birefringence. A strong correlation has also been found between the response time and the stability of the induced anisotropy toward illumination with unpolarized white light. One of the classes of E1aX polymers characterized by two-ring aromatic substituent in the main chain is a good candidate for optical data storage media. A recording energy of approximately 2 J/cm2 is sufficient to induce high refractive-index modulations of ?n = 0.13 in these materials, which is retained even at elevated temperatures (>130 °C). Long-term stability of greater than one year for the induced anisotropy has also been achieved.

  2. Cross-linked, biodegradable, cytocompatible salicylic acid based polyesters for localized, sustained delivery of salicylic acid: an in vitro study.

    PubMed

    Chandorkar, Yashoda; Bhagat, Rajesh K; Madras, Giridhar; Basu, Bikramjit

    2014-03-10

    In order to suppress chronic inflammation while supporting cell proliferation, there has been a continuous surge toward development of polymers with the intention of delivering anti-inflammatory molecules in a sustained manner. In the above backdrop, we report the synthesis of a novel, stable, cross-linked polyester with salicylic acid (SA) incorporated in the polymeric backbone and propose a simple synthesis route by melt condensation. The as-synthesized polymer was hydrophobic with a glass transition temperature of 1 °C, which increases to 17 °C upon curing. The combination of NMR and FT-IR spectral techniques established the ester linkages in the as-synthesized SA-based polyester. The pH-dependent degradation rate and the rate of release of salicylic acid from the as-synthesized SA-based polymer were studied at physiological conditions in vitro. The polyester underwent surface erosion and exhibited linear degradation kinetics in which a change in degradation rate is observed after 4-10 days and 24% mass loss was recorded after 4 months at 37 °C and pH 7.4. The delivery of salicylic acid also showed a similar change in slopes, with a sustained release rate of 3.5% in 4 months. The cytocompatibility studies of these polyesters were carried out with C2C12 murine myoblast cells using techniques like MTT assay and flow cytometry. Our results strongly suggest that SA-based polyester supports cell proliferation for 3 days in culture and do not cause cell death (<7%), as quantified by propidium iodide (PI) stained cells. Hence, these polyesters can be used as implant materials for localized, sustained delivery of salicylic acid and have applications in adjuvant cancer therapy, chronic wound healing, and as an alternative to commercially available polymers like poly(lactic acid) and poly(glycolic acid) or their copolymers. PMID:24517727

  3. Outgassing rate of Reemay Spunbonded Polyester and DuPont Double Aluminized Mylar

    SciTech Connect

    Todd, R.J.; Pate, D.; Welch, K.M.

    1993-08-01

    This paper presents the outgassing rates of two commercially available multi-layer insulation (MLI) materials commonly used in cryogenic applications. Both Reemay Spunbonded Polyester and DuPont Double Aluminized Mylar (DAM) were studied for outgassing species and respective rates, and the total amount of outgassed material. Measurements were made using a Fixed Aperture Technique. A sample was pumped on through an aperture of known size with a turbomolecular pump. Pressure vs. time was plotted for both Reemay and DAM, as well as the baseline system, and data conveniently extrapolated to {approx}1,000 hrs. A quadrupole residual gas analyzer was used to measure the outgassing species.

  4. Laparoscopic ventral hernia repair using expanded polytetrafluoroethylene–polyester mesh compound

    Microsoft Academic Search

    M. Farrakha

    2006-01-01

    Background  Many biomaterials and composites have been used in clinical and experimental laparoscopic ventral hernia repair. The ideal\\u000a prosthesis should allow firm binding to the abdominal wall without adhesion to the bowel.\\u000a \\u000a \\u000a \\u000a Methods  A compound prosthesis was made by circumferentially suturing a Gore-Tex mesh as visceral interface to a smaller polyester\\u000a mesh as parietal interface, and it was used in 46 laparoscopic

  5. Synthesis, characterization and application of new azo dyes derived from uracil for polyester fibre dyeing

    NASA Astrophysics Data System (ADS)

    Yazdanbakhsh, Mohamad-reza; Abbasnia, Masoumeh; Sheykhan, Mehdi; Ma'mani, Leila

    2010-08-01

    Some novel uracil derived azo compounds were synthesized by diazotization of substituted aromatic amines, amidine- and guanidine-like amines such as 2-aminopyridine and 2-aminopyrimidine, ortho-hydroxy aniline and ortho-hydroxy naphthyl amines and coupling reaction with 6-amino-1,3-dimethyluracil. Structures of the dyes were fully characterized by spectroscopic techniques (UV, 1H NMR, 13C NMR, CHN and IR). The dyes were applied to polyester, affording orange-yellow shades and the wash fastness of the dyeings was excellent.

  6. Injection-molded Sm–Fe–N anisotropic magnets using unsaturated polyester resin

    Microsoft Academic Search

    K. Ohmori; S. Hayashi; S. Yoshizawa

    2006-01-01

    New injection-molding technology has been developed using an unsaturated polyester (UP) resin in order to produce bonded Sm–Fe–N anisotropic magnets. Sheet magnets of 50mm×20mm×0.36mm are successfully made within a cycle time of 90s. Magnetic properties obtained are almost the same as those obtained in column magnets of ?10mm×7mm. Typical data of magnetic properties are as follows: Br=0.72T, HCJ=796kA\\/m and (BH)max=94.7kJ\\/m3.

  7. Pyrolysis study of a phosphorus-containing aliphatic–aromatic polyester and its nanocomposites with layered silicates

    Microsoft Academic Search

    A. I. Balabanovich; D. Pospiech; A. Korwitz; L. Häußler; C. Harnisch

    2009-01-01

    This paper deals with the thermal decomposition behaviour of a new fire retardant 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing aliphatic–aromatic polyester and its nanocomposites with natural layered silicate (montmorillonite) under inert atmosphere studied by TGA–FTIR, Pyrolysis–GC\\/MS of volatile products and ATR–FTIR of non-volatile decomposition products. The phosphorus-containing polyester undergoes decomposition in two steps between 340 and 516°C. The first step is associated with the

  8. Polymorphous computing fabric

    DOEpatents

    Wolinski, Christophe Czeslaw (Los Alamos, NM); Gokhale, Maya B. (Los Alamos, NM); McCabe, Kevin Peter (Los Alamos, NM)

    2011-01-18

    Fabric-based computing systems and methods are disclosed. A fabric-based computing system can include a polymorphous computing fabric that can be customized on a per application basis and a host processor in communication with said polymorphous computing fabric. The polymorphous computing fabric includes a cellular architecture that can be highly parameterized to enable a customized synthesis of fabric instances for a variety of enhanced application performances thereof. A global memory concept can also be included that provides the host processor random access to all variables and instructions associated with the polymorphous computing fabric.

  9. Synthesis and characterization of nanocomposites from amphipathy polyester grafted modified sericite and methylsilicone resin

    NASA Astrophysics Data System (ADS)

    Jiang, B.; Huang, Y. D.; Wang, Q.

    2014-04-01

    The synthetic process of amphipathy polyester grafted modified sericite and methylsilicone resin composites is studied. The analytical results showed that the initial decomposition temperature and the maximum release energy corresponding temperature are enhanced 120 °C and 51 °C. First, modified methylsilicone resin molecular structure is designed. Molecular chair of methylsilicone resin is grafted macromolecular polymer, which is synthesized by toluene-2, 4-diisocyanate modified sericite grafted amphipathy polyester. A modified sericite /methylsilicone resin composites are synthesized through the reaction of functionalized sericite with hydroxyl-terminated methylsilicone resin. X-ray diffraction analysis result showed that the methylsilicone resin has reacted with the modified sericite. Infrared spectra, x-ray photoelectron spectroscopy and nuclear magnetic resonance analysis show that the weak Si-OH band decreases and the strong Si-O-Si band increases. The mechanism of thermal stability is analyzed from the isolated oxygen atom and activated small molecule; interrupted activated Si-OH, steric hindrance. The result of study evidently shows a significant role in enhancing the decomposition temperature of the methylsilicone resin.

  10. A microbial factory for lactate-based polyesters using a lactate-polymerizing enzyme

    PubMed Central

    Taguchi, Seiichi; Yamada, Miwa; Matsumoto, Ken'ichiro; Tajima, Kenji; Satoh, Yasuharu; Munekata, Masanobu; Ohno, Katsuhiro; Kohda, Katsunori; Shimamura, Takashi; Kambe, Hiromi; Obata, Shusei

    2008-01-01

    Polylactate (PLA) is synthesized as a representative bio-based polyester by the chemo-bio process on the basis of metal catalyst-mediated chemical polymerization of lactate (LA) supplied by microbial fermentation. To establish the one-step microbial process for synthesis of LA-based polyesters, we explored whether polyhydroxyalkanoate (PHA) synthase would exhibit polymerizing activity toward a LA-coenzyme A (CoA), based on the fact that PHA monomeric constituents, especially 3-hydroxybutyrate (3HB), are structurally analogous to LA. An engineered PHA synthase was discovered as a candidate by a two-phase in vitro polymerization system previously developed. An LA-CoA producing Escherichia coli strain with a CoA transferase gene was constructed, and the generation of LA-CoA was demonstrated by capillary electrophoresis/MS analysis. Next, when the engineered PHA synthase gene was introduced into the resultant recombinant strain, we confirmed the one-step biosynthesis of the LA-incorporated copolyester, P(6 mol% LA-co-94 mol% 3HB), with a number-average molecular weight of 1.9 × 105, as revealed by gel permeation chromatography, gas chromatography/MS, and NMR. PMID:18978031

  11. Influence of magnetite, ilmenite and boron carbide on radiation attenuation of polyester composites

    NASA Astrophysics Data System (ADS)

    El-Sarraf, M. A.; El-Sayed Abdo, A.

    2013-07-01

    This work is concerned with studying polyester/ magnetite CUP/Mag (?=2.75 g cm-3) and polyester/ ilmenite CUP/Ilm (?=2.7 g cm-3) composites for shielding of medical facilities, laboratory hot cells and for various purposes. Mechanical and physical properties such as compressive, flexural and impact strengths, as well as, a.c. electrical conductivity, specific heat, water absorption and porosity have been performed to evaluate the composite capabilities for radiation shielding. A collimated beam from fission 252Cf (100 µg) neutron source and neutron-gamma spectrometer with stilbene scintillator based on the zero cross over method and pulse shape discrimination (P.S.D.) technique have been used to measure neutron and gamma ray spectra. Fluxes of thermal neutrons have been measured using the BF3 detector and thermal neutron detection system. The attenuation parameters, namely macroscopic effective removal cross-section ?R, total attenuation coefficient µ and macroscopic cross-section ? of fast neutrons, gamma rays and thermal neutrons respectively have been evaluated. Theoretical calculations using MCNP-4C2 code was used to calculate ?R,? and ?. Also, MERCSF-N program was used to calculate macroscopic effective removal cross-section ?R. Measured and calculated results were compared and reasonable agreement was found.

  12. Fabrics coated with lubricated nanostructures display robust omniphobicity

    NASA Astrophysics Data System (ADS)

    Shillingford, Cicely; MacCallum, Noah; Wong, Tak-Sing; Kim, Philseok; Aizenberg, Joanna

    2014-01-01

    The development of a stain-resistant and pressure-stable textile is desirable for consumer and industrial applications alike, yet it remains a challenge that current technologies have been unable to fully address. Traditional superhydrophobic surfaces, inspired by the lotus plant, are characterized by two main components: hydrophobic chemical functionalization and surface roughness. While this approach produces water-resistant surfaces, these materials have critical weaknesses that hinder their practical utility, in particular as robust stain-free fabrics. For example, traditional superhydrophobic surfaces fail (i.e., become stained) when exposed to low-surface-tension liquids, under pressure when impacted by a high-velocity stream of water (e.g., rain), and when exposed to physical forces such as abrasion and twisting. We have recently introduced slippery lubricant-infused porous surfaces (SLIPS), a self-healing, pressure-tolerant and omniphobic surface, to address these issues. Herein we present the rational design and optimization of nanostructured lubricant-infused fabrics and demonstrate markedly improved performance over traditional superhydrophobic textile treatments: SLIPS-functionalized cotton and polyester fabrics exhibit decreased contact angle hysteresis and sliding angles, omni-repellent properties against various fluids including polar and nonpolar liquids, pressure tolerance and mechanical robustness, all of which are not readily achievable with the state-of-the-art superhydrophobic coatings.

  13. Fabrics coated with lubricated nanostructures display robust omniphobicity.

    PubMed

    Shillingford, Cicely; MacCallum, Noah; Wong, Tak-Sing; Kim, Philseok; Aizenberg, Joanna

    2014-01-10

    The development of a stain-resistant and pressure-stable textile is desirable for consumer and industrial applications alike, yet it remains a challenge that current technologies have been unable to fully address. Traditional superhydrophobic surfaces, inspired by the lotus plant, are characterized by two main components: hydrophobic chemical functionalization and surface roughness. While this approach produces water-resistant surfaces, these materials have critical weaknesses that hinder their practical utility, in particular as robust stain-free fabrics. For example, traditional superhydrophobic surfaces fail (i.e., become stained) when exposed to low-surface-tension liquids, under pressure when impacted by a high-velocity stream of water (e.g., rain), and when exposed to physical forces such as abrasion and twisting. We have recently introduced slippery lubricant-infused porous surfaces (SLIPS), a self-healing, pressure-tolerant and omniphobic surface, to address these issues. Herein we present the rational design and optimization of nanostructured lubricant-infused fabrics and demonstrate markedly improved performance over traditional superhydrophobic textile treatments: SLIPS-functionalized cotton and polyester fabrics exhibit decreased contact angle hysteresis and sliding angles, omni-repellent properties against various fluids including polar and nonpolar liquids, pressure tolerance and mechanical robustness, all of which are not readily achievable with the state-of-the-art superhydrophobic coatings. PMID:24334333

  14. Dilatation of Stent-Grafts by Luminal Pressures: Experimental Evaluation of Polytetrafluoroethylene (PTFE) and Woven Polyester Grafts

    SciTech Connect

    Suzuki, Kojiro; Ishiguchi, Tsuneo; Kawatsu, Shoji; Iwai, Hiroyoshi; Maruyama, Kunihiro; Ishigaki, Takeo [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

    2001-03-15

    Purpose: To evaluate the effect on dilatation of three types of covering materials used for endovascular stent-grafts.Methods: Stent-grafts with three types of covering material [0.1-mm polytetrafluoroethylene (PTFE), 0.2-mm PTFE, and 0.15-mm woven polyester] were placed in a fluid circuit. For the pulsatile pressure test, the luminal pressure of 190/130 mmHg was loaded up to 300,000 pulses. For the static pressure test, the luminal pressure was increased from 50 to 300 mmHg at 50-mmHg increments. The percent of dilatation of each stent-graft was compared.Results: The 0.1-mm PTFE stent-graft was significantly more dilated than the 0.2-mm PTFE and the 0.15-mm woven polyester stent-graft (p < 0.005) in both examinations. There was no significant difference between the 0.2-mm PTFE and the 0.15-mm woven polyester stent-grafts. The dilatation of the 0.1-mm PTFE stent-graft was irreversible.Conclusion: The 0.15-mm woven polyester and the 0.2-mm PTFE stent-grafts may be preferable to the 0.1-mm PTFE stent-graft with regard to dilatation and deformity.

  15. An expert system for life prediction of woven roving glass fiber reinforced polyester under cyclic bending loading

    Microsoft Academic Search

    Aly A. Helmy

    As the study of fatigue failure of composite materials needs a large number of experiments as well as long time, so there is a need for new computational technique to expand the spectrum of the results and to save time. The present work represents a new technique to predict the fatigue life of Woven Roving Glass Fiber Reinforced Polyester subjected

  16. Powder characteristics and coating conditions of fresh and reused polyester resins for electrostatic powder coating: powder recycling and loss prevention

    Microsoft Academic Search

    A. W. Lothongkum; R. Nonthapone; K. Seangkiatiyuth; W. Tanthapanichkoon

    2007-01-01

    Powder characteristics and coating conditions are significant factors in electrostatic powder coating. In this work, powder characteristics of the reused polyester resin or recycled powder particles in terms of shape, size, particle size distribution, moisture content, density, flowability, fluidity and chargeability were compared with those of fresh resin or as-received powder to consider powder recycling. The coating conditions for a

  17. Dibutyryl cAMP-Inducible Alkaline Phosphatase in Animal Cell Plasma Membranes: Fluorescence Detection of Mutant Clones on Polyester Cloth

    Microsoft Academic Search

    James R. Gum; Christian R. H. Raetz

    1983-01-01

    We have developed a rapid screening assay that allows us to estimate the alkaline phosphatase content of mouse L-M cell colonies immobilized on polyester cloth. This permitted the identification and isolation of two mutant clones with increased constitutive alkaline phosphatase activity and six clones that fail to express this activity when treated with dibutyryl cyclic AMP. Both of the strains

  18. Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy Efficient Wood-Plastic Composites

    Microsoft Academic Search

    David N. Thompson; Robert W. Emerick; Alfred B. England; James P. Flanders; Frank J. Loge; Katherine A. Wiedeman; Michael P. Wolcott

    2010-01-01

    In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered

  19. Polyester-Poly(Ethylene Glycol) Nanoparticles Loaded with the Pure Antiestrogen RU 58668: Physicochemical and Opsonization Properties

    Microsoft Academic Search

    Thibault Ameller; Véronique Marsaud; Philippe Legrand; Ruxandra Gref; Gillian Barratt; Jack-Michel Renoir

    2003-01-01

    Purpose. The pure antiestrogen RU58668 (RU) was encapsulated within nanospheres (NS) and nanocapsules (NC) prepared from different polyester copolymers with poly(ethylene glycol) (PEG) chains. The influence of their physicochemical properties on drug release in vitro and their susceptibility to opsonization were evaluated.

  20. The Effect of Fibre Blend on Comfort Characteristics of Elastic Knitted Fabrics Used for Pressure Garments

    NASA Astrophysics Data System (ADS)

    Bera, M.; Chattopadhay, R.; Gupta, D.

    2014-04-01

    Comfort characteristics of pressure garments are very important issue as these garments are recommended to wear for 23 h a day to recover from venous problem, scar maturation, orthopedic problems, post surgery, post pregnancy and many other problems. The patients mostly stop using such kind of medical devices because of itching, perspiration and other comfort relate problems. Mostly nylon, polyester and cotton fibres are used in the fabrics. Nylon, polyester are used for strength whereas cotton is used for good comfort related properties. It may be possible to get some certain type of strength and comfort property together by using both types of fibre. Less information is available in this aspect. In this paper, fabric samples were prepared in knit construction by varying the nylon and cotton blend percentage. Comfort properties in terms of air permeability, thermal property, water vapor permeability, surface friction behavior and wicking properties have been studied extensively. The results showed that, the fibre blend percentage did not have any influence on pressure generation. Air permeability and thermal properties were also not affected. However, water vapor permeability and wicking behavior vary significantly. Increase in nylon percentage increases both the water vapor permeability and wicking. It can be thus concluded that, manufacturers can choose fibre blend percentage according to the requirement.

  1. Effect of methyl groups on the thermal properties of polyesters from methyl substituted 1,4-butanediols and 4,4'-biphenyldicarboxylic acid

    Microsoft Academic Search

    Albert J. B. Loman; Does van der Leen; Adriaan Bantjes; Ivan Vulic

    1995-01-01

    Results are reported on the effect of lateral methyl groups on the thermal properties of a series of polyesters prepared from diethyl 4,4-biphenyldicarboxylate and various methyl substituted 1,4-butanediols. The diols were 1,4-butanediol; 2-methyl-1,4-butanediol; 2,2-dimethyl-1,4-butanediol; 2,3-dimethyl-1,4-butanediol; 2,2,3-trimethyl-1,4-butanediol; and 2,2,3,3-tetramethyl-1,4-butanediol. Apart from the tetramethyl derivatve, the transition temperatures of the methyl substituted polyesters were lower with respect of the unsubstituted polyester. On

  2. DESIGN [fabrication] BUILD

    E-print Network

    Rader, Nicolas Glen

    2006-01-01

    DESIGN [fabrication] BUILD proposes a new relationship among the architect, homeowner, and fabricator/assembler through the use of parametric software in order to create a truly customizable prefabricated home. This ...

  3. Contextualizing urban mobile fabrics

    E-print Network

    Lin, Michael Chia-Liang

    2007-01-01

    This thesis is focus on the urban fabric issues. To be more specific, I will focus on the "Mobile Fabrics" within the larger Asian urban context. Instead of working with a specific geographical site; I will focus on the ...

  4. The effects of a moisture-wicking fabric shirt on the physiological and perceptual responses during acute exercise in the heat.

    PubMed

    De Sousa, Justin; Cheatham, Christopher; Wittbrodt, Matthew

    2014-11-01

    This study investigated the effects that a form fitted, moisture-wicking fabric shirt, promoted to have improved evaporative and ventilation properties, has on the physiological and perceptual responses during exercise in the heat. Ten healthy male participants completed two heat stress tests consisting of 45 min of exercise (50% VO2peak) in a hot environment (33 °C, 60% RH). One heat stress test was conducted with the participant wearing a 100% cotton short sleeved t-shirt and the other heat stress test was conducted with the participant wearing a short sleeved synthetic shirt (81% polyester and 19% elastane). Rectal temperature was significantly lower (P < 0.05) in the synthetic condition during the last 15 min of exercise. Furthermore, the synthetic polyester shirt retained less sweat (P < 0.05). As exercise duration increases, the ventilation and evaporation properties of the synthetic garment may prove beneficial in the preservation of body temperature during exercise in the heat. PMID:24768089

  5. URANIUM DIOXIDE FABRICATION

    Microsoft Academic Search

    D. W. Brite; R. J. Anicetti

    1960-01-01

    The techniques developed for fabricating (UOâ fuel element cores ; and swageable powders at HAPO are described. A simplified flow chart of some of ; the processes is presented. Types of fuel cores fabricated since the program ; began in 1956 are indicated. The experiences and observations are related both ; in fabricating the uranium dioxide fuel element cores for

  6. Exploring Products: Nano Fabrics

    NSDL National Science Digital Library

    Nanoscale Informal Science Education Network

    2010-01-01

    In this activity, learners explore how the application of nano-sized "whiskers" can protect clothing from stains. Learners investigate the hydrophobic properties of pants made from nano fabric and ordinary fabric. Use this activity to talk about products that we can already buy that use nanotechnology, like treated fabrics, water filters, sunscreen and stuffed animals that have silver nanoparticles.

  7. Calcarides A–E, Antibacterial Macrocyclic and Linear Polyesters from a Calcarisporium Strain

    PubMed Central

    Silber, Johanna; Ohlendorf, Birgit; Labes, Antje; Erhard, Arlette; Imhoff, Johannes F.

    2013-01-01

    Bioactive compounds were detected in crude extracts of the fungus, Calcarisporium sp. KF525, which was isolated from German Wadden Sea water samples. Purification of the metabolites from the extracts yielded the five known polyesters, 15G256?, ?-2, ?, ?-2 and ? (1–5), and five new derivatives thereof, named calcarides A–E (6–10). The chemical structures of the isolated compounds were elucidated on the basis of one- and two-dimensional NMR spectroscopy supported by UV and HRESIMS data. The compounds exhibited inhibitory activities against Staphylococcus epidermidis, Xanthomonas campestris and Propionibacterium acnes. As the antibacterial activities were highly specific with regard to compound and test strain, a tight structure-activity relationship is assumed. PMID:23994907

  8. A new myrsinol-type diterpene polyester from Euphorbia dracunculoides Lam.

    PubMed

    Wang, Li; Yang, Jing; Chi, Yu-Qian; Ouyang, Wen-Bin; Zang, Zhen; Huang, Sheng-Xiong; Cao, Pei; Zhao, Yong

    2015-08-01

    A new myrsinol-type diterpene polyester, 14-deoxo-3?-O-propinoyl-2?,5?,7?,15?-tetra-O-acetyl-14?-O-benzoyl-myrsinol (1), and its known analogue, 14-deoxo-3?-O-prorionyl-5?,15?-di-O-acetyl-7?-O-nicotinoyl-myrsinol-14?-acetate (2), together with a monoterpenoid, pubinernoid A (3), two indole alkaloids, neoechinulin A (4) and dihydroxyisoechinulin A (5), two benzene derivatives, siringin (6) and (3-methoxyphenyl) acetic acid (7), were isolated from the 70% acetone extract of the aerial parts of Euphorbia dracunculoides Lam. Their structures were elucidated on the basis of spectroscopic evidence and comparison with literature reports. The absolute configuration of 1 was deduced by comparing experimental and calculated ECD spectra. Among them, compounds 4 and 5 were first obtained from the plant source. In addition, the (13)C NMR data of compound 2 was reported for the first time. PMID:25605432

  9. Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

    NASA Astrophysics Data System (ADS)

    Kan, C. W.; Kwong, C. H.; Ng, S. P.

    2015-08-01

    Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

  10. Photochemical cutting of fabrics

    DOEpatents

    Piltch, Martin S. (Los Alamos, NM)

    1994-01-01

    Apparatus for the cutting of garment patterns from one or more layers of fabric. A laser capable of producing laser light at an ultraviolet wavelength is utilized to shine light through a pattern, such as a holographic phase filter, and through a lens onto the one or more layers of fabric. The ultraviolet laser light causes rapid photochemical decomposition of the one or more layers of fabric, but only along the pattern. The balance of the fabric of the one or more layers of fabric is undamaged.

  11. Photochemical cutting of fabrics

    SciTech Connect

    Piltch, M.S.

    1994-11-22

    Apparatus is described for the cutting of garment patterns from one or more layers of fabric. A laser capable of producing laser light at an ultraviolet wavelength is utilized to shine light through a pattern, such as a holographic phase filter, and through a lens onto the one or more layers of fabric. The ultraviolet laser light causes rapid photochemical decomposition of the one or more layers of fabric, but only along the pattern. The balance of the fabric of the one or more layers of fabric is undamaged. 1 fig.

  12. [Progressive complications associated with polyester arterial prostheses. Study of 61 specimens following surgical excision].

    PubMed

    Guidoin, R; King, M; Marois, M; Roy, P E; Rolland, C; Marceau, D; David, M; Descotes, J; Bénichoux, R; Agé, B

    1987-01-01

    Reports of individual surgical cases tend to be anecdotal because of the unique circumstances surrounding the patient, the surgeon, the intervention and, where applicable, the prosthetic device. To overcome this limitation the authors have taken a wider collaborative approach and report the analysis of 61 explanted polyester arterial prostheses associated with delayed complications on 53 patients reoperated upon in six different French hospitals. One advantage of such an independent and centralized retrieval programme is that the impact of centre specific factors, such as patient selection and surgical techniques, is minimized. Consequently, by following a standardized protocol for the evaluation of the morphologic, pathologic and mineralogic characteristics of the tissue surrounding the excised grafts, as well as the textile structure of the prostheses themselves, it has been possible to distinguish between iatrogenic and disease related complications and to demonstrate a number of general findings associated with the clinical performance of polyester arterial prostheses. Complications such as thromboses, infections and false aneurysms appear to occur randomly after different lengths of implantation, thicker fibrous tissue capsules are associated with velour grafts with highly textured yarns, the incidence of mineralized tissue and of endothelialized luminal surfaces is rare, weft knitted textile prostheses appear less mechanically stable and more sensitive to iatrogenic trauma than warp knitted, and the incidences of lipid and cholesterol adsorption, bacterial colonization and sterile fluid loss need further investigation. These observations lead to the recommendation that for patients with longer life expectancies surgeons should consider selecting low porosity, woven or warped knitted prostheses which contain yarns that have not been highly textured. PMID:3694053

  13. Development and long-term in vivo evaluation of a biodegradable urethane-doped polyester elastomer

    PubMed Central

    Dey, Jagannath; Tran, Richard T.; Shen, Jinhui; Tang, Liping; Yang, Jian

    2011-01-01

    We have recently reported upon the development of crosslinked urethane-doped polyester (CUPE) network elastomers, which was motivated by the desire to overcome the drawbacks presented by crosslinked network polyesters and biodegradable polyurethanes for soft tissue engineering applications. Although the effect of the isocyanate content and post-polymerization conditions on the material structure-property relationship was examined in detail, the ability of the diol component to modulate the material properties was only studied briefly. Herein, we present a detailed report on the development of CUPE polymers synthesized using diols 4, 6, 8, 10, or 12 methylene units in length in order to investigate what role the diol component plays on the resulting material’s physical properties, and assess their long-term biological performance in vivo. An increase in the diol length was shown to affect the physical properties of the CUPE polymers primarily through lowered polymeric crosslinking densities and elevated material hydrophobicity. The use of longer chain diols resulted in CUPE polymers with increased molecular weights resulting in higher tensile strength and elasticity, while also increasing the material hydrophobicity to lower bulk swelling and prolong the polymer degradation rates. Although the number of methylene units largely affected the physical properties of CUPE, the choice of diol did not affect the overall polymer cell/tissue-compatibility both in vitro and in vivo. In conclusion, we have established the diol component as an important parameter in controlling the structure-property relationship of the polymer in addition to diisocyanate concentration and post-polymerization conditions. Expanding the family of CUPE polymers increases the choices of biodegradable elastomers for tissue engineering applications. PMID:22184499

  14. Fungal communities associated with the biodegradation of polyester polyurethane buried under compost at different temperatures.

    PubMed

    Zafar, Urooj; Houlden, Ashley; Robson, Geoffrey D

    2013-12-01

    Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, particularly by fungi. In this study, we investigated the impact of composting on PUs, as composting is a microbially rich process that is increasingly being used for the processing of green waste and food waste as an economically viable alternative to landfill disposal. PU coupons were incubated for 12 weeks in fresh compost at 25°C, 45°C, and 50°C to emulate the thermophilic and maturation stages of the composting process. Incubation at all temperatures caused significant physical deterioration of the polyester PU coupons and was associated with extensive fungal colonization. Terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of the fungal communities on the PU surface and in the surrounding compost revealed that the population on the surface of PU was different from the surrounding compost community, suggesting enrichment and selection. The most dominant fungi identified from the surfaces of PU coupons by pyrosequencing was Fusarium solani at 25°C, while at both 45°C and 50°C, Candida ethanolica was the dominant species. The results of this preliminary study suggest that the composting process has the potential to biodegrade PU waste if optimized further in the future. PMID:24056469

  15. Structural properties of biodegradable polyesters and rheological behaviour of their dispersions and films.

    PubMed

    Santoveña, A; Alvarez-Lorenzo, C; Concheiro, A; Llabrés, M; Fariña, J B

    2005-01-01

    This paper focuses on the dependence of the rheological properties of PLA-PEG and PLGA dispersions and films on the polymer structural properties, in order to obtain useful information to predict and explain the performance of polyester films as drug-delivery systems. In this study, one PLA-PEG and three PLGA polymers of different molecular mass were synthesized and characterized by NMR, GPC, DSC and TGA-FT-IR. To characterize the viscoelastic behaviour of concentrated solutions in dichloromethane and of the films obtained by a solvent-casting technique, oscillatory shear rheometry was used. The polymer dispersions showed a characteristic Newtonian viscous behaviour, but with different consistency index depending on the nature of the polymer. Freshly prepared, PLGA and PLA-PEG films had elastic modulus (G') greater than viscous modulus (G"). The decrease in both moduli caused by an increase in temperature from 25 to 37 degrees C was especially marked for the polymers with T(g) below or around 25 degrees C (PLGA 27 kDa and PLA-PEG 27 kDa). After being immersed in pH 7.4 aqueous solution for one week, PLGA films showed a significant increase in both G' and G", due to the promotion of polymer-polymer interactions in a non-solvent medium. In contrast, the PLA-PEG film became softer and more hydrated, due to the amphiphilic character of the polymer. The water taken up by the film acted as a plasticizer and induced the softening of the system. These results suggest that the presence of PEG chains exerts a strong influence on the mechanical properties of polyesters films and, possibly, the performance as coating or matrices of drug-delivery systems. PMID:16001721

  16. Contribution of soil esterase to biodegradation of aliphatic polyester agricultural mulch film in cultivated soils.

    PubMed

    Yamamoto-Tamura, Kimiko; Hiradate, Syuntaro; Watanabe, Takashi; Koitabashi, Motoo; Sameshima-Yamashita, Yuka; Yarimizu, Tohru; Kitamoto, Hiroko

    2015-01-01

    The relationship between degradation speed of soil-buried biodegradable polyester film in a farmland and the characteristics of the predominant polyester-degrading soil microorganisms and enzymes were investigated to determine the BP-degrading ability of cultivated soils through characterization of the basal microbial activities and their transition in soils during BP film degradation. Degradation of poly(butylene succinate-co-adipate) (PBSA) film was evaluated in soil samples from different cultivated fields in Japan for 4 weeks. Both the degradation speed of the PBSA film and the esterase activity were found to be correlated with the ratio of colonies that produced clear zone on fungal minimum medium-agarose plate with emulsified PBSA to the total number colonies counted. Time-dependent change in viable counts of the PBSA-degrading fungi and esterase activities were monitored in soils where buried films showed the most and the least degree of degradation. During the degradation of PBSA film, the viable counts of the PBSA-degrading fungi and the esterase activities in soils, which adhered to the PBSA film, increased with time. The soil, where the film was degraded the fastest, recorded large PBSA-degrading fungal population and showed high esterase activity compared with the other soil samples throughout the incubation period. Meanwhile, esterase activity and viable counts of PBSA-degrading fungi were found to be stable in soils without PBSA film. These results suggest that the higher the distribution ratio of native PBSA-degrading fungi in the soil, the faster the film degradation is. This could be due to the rapid accumulation of secreted esterases in these soils. PMID:25852987

  17. Manufacturing carbon nanofibers toughened polyester\\/glass fiber composites using vacuum assisted resin transfer molding for enhancing the mode-I delamination resistance

    Microsoft Academic Search

    Ramin Sadeghian; Sudhir Gangireddy; Bob Minaie; Kuang-Ting Hsiao

    2006-01-01

    Polymer composite materials reinforced by continuous fibers have excellent in-plane strength but are usually weak against delamination. This paper presents an experimental study of using carbon nanofibers (CNF) to improve the interlaminar fracture properties of polyester\\/glass fiber composites. Surfactant-treated CNF were dispersed in polyester resin and then the CNF-resin suspension was infused to impregnate a glass fiber preform using vacuum

  18. The radiation destruction of crystalline polymers—I. The effect of radiation crosslinking on crystallinities of polyesters

    NASA Astrophysics Data System (ADS)

    Yiqun, Zhang; Danliang, Jin; Xinfang, Chen; Zhanchen, Chui; Yuxia, Luo; Hua, Li Shu

    1994-05-01

    Changes in crystallinity of crystalline polyethylene glycol terephthalate (PET) and polyhexamethylene terephthalate (PHT) irradiated by ?-ray (0-30 MGy) were investigated by means of a differential scanning calorimeter (DSC). The results of the first-run indicated that the melting point of both polyesters decreases with the increase of dose, and the half widths of melting peaks decrease at first and then increase with dose, that is there is a minimum half-width at some dose. The results of the second-run DSC indicate that the properties of recrystalline material are related to the crystal states in which the samples were irradiated. The entropies of fusion, ? S, were calculated from Tm and ? H. ? S decreases with dose increase for each polyester, and PHT, in which more crosslinking occurs, gives greater ? S than PET. The result is discussed from the point of view of crosslinking taking place within each crystal.

  19. Fabrics for aeronautic construction

    NASA Technical Reports Server (NTRS)

    Walen, E D

    1918-01-01

    The Bureau of Standards undertook the investigation of airplane fabrics with the view of finding suitable substitutes for the linen fabrics, and it was decided that the fibers to be considered were cotton, ramie, silk, and hemp. Of these, the cotton fiber was the logical one to be given primary consideration. Report presents the suitability, tensibility and stretching properties of cotton fabric obtained by laboratory tests.

  20. Poly(lactic acid) blends with desired end-use properties by addition of thermoplastic polyester elastomer and MDI

    Microsoft Academic Search

    Haydar U. Zaman; Jun Cheol Song; Lee-Soon Park; Inn-Kyu Kang; Soo-Young Park; Giseop Kwak; Byung-sik Park; Keun-Byoung Yoon

    2011-01-01

    The disadvantages of the poor mechanical properties of polylactic acid (PLA) limit its ability to be used in a wide number\\u000a of applications. Melt blending of PLA and thermoplastic polyester elastomer (TPEE) has been performed in an effort to toughen\\u000a the PLA without significant losses in modulus and ultimate tensile strength. In order to enhance the compatibility of PLA\\u000a and

  1. Enzymatic and whole-cell synthesis of lactate-containing polyesters: toward the complete biological production of polylactate

    Microsoft Academic Search

    Ken’ichiro Matsumoto; Seiichi Taguchi

    2010-01-01

    The importance of polylactic acid, a representative bio-based polyester, has been established on a worldwide scale in response\\u000a to emerging global environmental problems such as green house gas emission and limited petroleum consumption. The current\\u000a methods for generating this bio-based polymer involve biological synthesis and lactic acid (LA) fermentation, followed by\\u000a chemical ring-opening polymerization. Among the research community working on

  2. Microspectroscopic evaluations of the interfacial degradation by absorbed water in a model composite of an aramid fibre and unsaturated polyester

    Microsoft Academic Search

    M. Kawagoe; M. Takeshima; M. Nomiya; J. Qiu; M. Morita; W. Mizuno; H. Kitano

    1999-01-01

    The laser Raman and the Fourier transform infra-red (FTi.r.) microspectroscopic analyses were conducted to monitor the interfacial degradation process in a model composite of an aramid fibre (Kevlar 49) and unsaturated polyester (UP) exposed to water at 30 and 90°C. For micro-laser Raman spectroscopy, a single long fibre was embedded in the UP resin being subjected to static tension. Removing

  3. Electrochemical identification of anthraquinone-based dyes in solid microsamples by square wave voltammetry using graphite\\/polyester composite electrodes

    Microsoft Academic Search

    A. Doménech-Carbó; M. T. Doménech-Carbó; M. C. Saurí-Peris; J. V. Gimeno-Adelantado; F. Bosch-Reig

    2003-01-01

    An electrochemical method for identifying anthraquinone-type dyes in microsamples from works of art, based in the voltammetry of microparticles approach, is reported. Upon attachment onto graphite\\/polyester composite electrodes, natural pigments aloe, henna, cochineal red, madder lake, kermes, shellac, and alizarin and purpurin taken as reference materials can be identified from their square wave voltammetric profiles in MeCN (0.10 mol Lу

  4. Effect of Phase Arrangement on Solid State Mechanical and Thermal Properties of Polyamide 6\\/Polylactide Based Co-polyester Blends

    Microsoft Academic Search

    VLADIMIR SEDLARIK; ONON OTGONZUL; TAKESHI KITANO; ADRIANA GREGOROVA; MARTA HRABALOVA; ITA JUNKAR; UROS CVELBAR; MIRAN MOZETIC; PETR SAHA

    2011-01-01

    The main goal of this work is to correlate morphological parameters of the binary blend of polyamide 6 (PA6) and a polylactide based biodegradable co-polyester blend (BioFlex) (scanning electron microscopy, solvent extraction method) with the solid-state mechanical properties (stress strain analysis) as well as thermal (differential scanning calorimetry) and selected physico-chemical characteristics (Fourier transform infrared spectroscopy and water uptake analysis).

  5. Effect of Phase Arrangement on Solid State Mechanical and Thermal Properties of Polyamide 6\\/Polylactide Based Co-polyester Blends

    Microsoft Academic Search

    Vladimir Sedlarik; Onon Otgonzul; Takeshi Kitano; Adriana Gregorova; Marta Hrabalova; Ita Junkar; Uros Cvelbar; Miran Mozetic; Petr Saha

    2012-01-01

    The main goal of this work is to correlate morphological parameters of the binary blend of polyamide 6 (PA6) and a polylactide (PLA) based biodegradable co-polyester blend (BioFlex) (scanning electron microscopy, solvent extraction method) with the solid-state mechanical properties (stress strain analysis) as well as thermal (differential scanning calorimetry) and selected physico-chemical characteristics (Fourier transform infrared spectroscopy and water uptake

  6. Optical and thermal properties of fibres: effect of boiling and stretching on some macro-structural parameters of polyester fibres

    Microsoft Academic Search

    I. M. Fouda; H. M. Shabana

    1999-01-01

    Unboiled and boiled polyester (PET) (Egyptian manufacturer) fibres having irregular cross-sectional shape were stretched at room temperature using a mechanical device with a double-beam interference microscope. The optical results obtained were used for calculating some macro-structural parameters. The evaluated density results were used to calculate the degree of crystallinity, the form birefringence, the mean square density fluctuation and some other

  7. Synthesis and Thermal Study of Cured Epoxy-Acrylate-Maleate, Unsaturated Polyester and Their Interpenetrating Networks of Varying Compositions

    Microsoft Academic Search

    P. K. Mer; P. H. Parsania

    2011-01-01

    Epoxy-acrylate-maleate of bisphenol-C (ECAM), unsaturated polyester resin of phthalic anhydride, maleic anhydride and propylene glycol (PMP) were synthesized. ECAM, PMP and their varying compositions (25–75 wt%) were cured using MEKP and cobalt naphthenate and characterized by IR, DSC and TGA techniques. Interpenetrating networks possess intermediate thermal stability of ECAM (300°C) and PMP (227°C) and followed single step degradation with fractional order

  8. Optical Fabrication Nightmares

    NASA Astrophysics Data System (ADS)

    Voras, Robert P.

    1980-09-01

    Optical fabrication nightmares come in a variety of forms. They are generally caused by "toos": too thin, too thick, too large, too small, too many, too few, etc. In practice I believe many optical fabrication problems could be eliminated - or at least minimized -if there were more communication between the designer and the process engineer, up front. However, since the purpose of this paper is to describe difficult items to fabricate and possible solutions for their fabrication, I will get off my soap-box and proceed to my assigned task.

  9. Combined size exclusion chromatography, supercritical fluid chromatography and electrospray ionization mass spectrometry for the analysis of complex aliphatic polyesters.

    PubMed

    Pretorius, Nadine O; Willemse, Chandré M; de Villiers, André; Pasch, Harald

    2014-02-21

    Aliphatic polyesters are complex products of polycondensation that are distributed regarding the degree of polycondensation, the end group functionality and the molecular topology. To address the molecular heterogeneity of polyesters based on phthalic acid and propylene glycol, for the first time the combination of SEC, SFC and ESI-MS have been used. In a first set of experiments, samples were fractionated by SEC and the collected fractions analyzed by SFC for a tentative assignment of the degrees of polycondensation. More conclusive results were obtained by semi-preparative SFC fractionation of the bulk samples and the subsequent analysis of the collected fractions by ESI-MS. The ESI-MS spectra of the SFC fractions provided detailed information on the presence of linear and cyclic oligomers, their degrees of polycondensation and their end groups. Information on the presence of propylene oxide oligomers was also obtained and it was shown how they were inserted in the polymer structures. Compared to previous work, the present approach provides significantly more detailed information on the molecular complexity of aliphatic polyesters. This is mainly due to the fact that SFC has been used as the second chromatographic dimension which is known to have superior separation capabilities. PMID:24472839

  10. Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems

    PubMed Central

    Goeschen, Catrin

    2013-01-01

    Summary Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 • in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed ‘hot spots’ in polyesters that are particularly vulnerable to attack by NO3 • and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions. PMID:24204400

  11. Lipase-catalyzed synthesis of azido-functionalized aliphatic polyesters towards acid-degradable amphiphilic graft copolymers.

    PubMed

    Wu, Wan-Xia; Wang, Na; Liu, Bei-Yu; Deng, Qing-Feng; Yu, Xiao-Qi

    2014-02-28

    A series of novel aliphatic polyesters with azido functional groups were synthesized via the direct lipase-catalyzed polycondensation of dialkyl diester, diol and 2-azido-1,3-propanediol (azido glycerol) using immobilized lipase B from Candida antarctica (CALB). The effects of polymerization conditions including reaction time, temperature, enzyme amount, substrates and monomer feed ratio on the molecular weights of the products were studied. The polyesters with pendant azido groups were characterized by (1)H NMR, (13)C NMR, 2D NMR, FTIR, GPC and DSC. Alkyne end-functionalized poly(ethylene glycol) containing a cleavable acetal group was then grafted onto the polyester backbone by copper-catalyzed azide-alkyne cycloaddition (CuAAC, click chemistry). Using fluorescence spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM), these amphiphilic graft copolymers were found to readily self-assemble into nanosized micelles in aqueous solution with critical micelle concentrations between 0.70 and 1.97 mg L(-1), and micelle sizes from 20-70 nm. The degradation of these polymers under acidic conditions was investigated by GPC and (1)H NMR spectroscopy. Cell cytotoxicity tests indicated that the micelles had no apparent cytotoxicity to Bel-7402 cells, suggesting their potential as carriers for controlled drug delivery. PMID:24652240

  12. Mechanical and thermal studies of unsaturated polyester-toughened epoxy composites filled with amine-functionalized nanosilica

    NASA Astrophysics Data System (ADS)

    Jaya Vinse Ruban, Y.; Ginil Mon, S.; Vetha Roy, D.

    2013-02-01

    The inter-crosslinking networks of unsaturated polyester (UP)-toughened epoxy-nanosilica hybrid nanocomposites have been developed. Epoxy resin was toughened with 5 and 10% (by wt) of unsaturated polyester using benzoyl peroxide as radical initiator and 4,4'-diaminodiphenylmethane (DDM) as a curing agent at appropriate condition, and the resulting product was identified by FT-IR spectra. Unsaturated polyester-toughened epoxy system (10%) was further filled with 1, 3, 5 and 7% (by wt) of amine-functionalized nanosilica particles prepared by sol-gel method. Modified nanosilica-filled hybrid UP-epoxy matrices developed in the form of casting were characterized for their thermal, mechanical properties and water absorption capacity according to ASTM standards. The degree of dispersion of nanosilica in the matrices was investigated by SEM technique. Mechanical testing data indicate that the introduction of UP into epoxy resin has improved the impact strength. Significant improvement in the flexural properties, tensile properties and impact strength were observed in the UP-epoxy blends with increase in the percentage of amine-modified nanosilica particles. The T g value decreases with UP toughening and increases with concentration of modified nanosilica on the UP-epoxy matrix. The water absorption behavior is found to decrease with UP toughening and concentration of modified nanosilica on the UP-epoxy matrix.

  13. New poly(ester urea) derived from L-leucine: electrospun scaffolds loaded with antibacterial drugs and enzymes.

    PubMed

    Díaz, Angélica; del Valle, Luis J; Tugushi, David; Katsarava, Ramaz; Puiggalí, Jordi

    2015-01-01

    Electrospun scaffolds from an amino acid containing poly(ester urea) (PEU) were developed as promising materials in the biomedical field and specifically in tissue engineering applications. The selected poly(ester urea) was obtained with a high yield and molecular weight by reaction of phosgene with a bis(?-aminoacyl)-?,?-diol-diester monomer. The polymer having L-leucine, 1,6-hexanediol and carbonic acid units had a semicrystalline character and relatively high glass transition and melting temperatures. Furthermore it was highly soluble in most organic solvents, an interesting feature that facilitated the electrospinning process and the effective incorporation of drugs with bactericidal activity (e.g. biguanide derivatives such as clorhexidine and polyhexamethylenebiguanide) and enzymes (e.g. ?-chymotrypsin) that accelerated the degradation process. Continuous micro/nanofibers were obtained under a wide range of processing conditions, being diameters of electrospun fibers dependent on the drug and solvent used. Poly(ester urea) samples were degradable in media containing lipases and proteinases but the degradation rate was highly dependent on the surface area, being specifically greater for scaffolds with respect to films. The high hydrophobicity of new scaffolds had repercussions on enzymatic degradability since different weight loss rates were found depending on how samples were exposed to the medium (e.g. forced or non-forced immersion). New scaffolds were biocompatible, as demonstrated by adhesion and proliferation assays performed with fibroblast and epithelial cells. PMID:25492010

  14. Lobesia botrana IPM: electrospun polyester microfibers serve as biodegradable sex pheromone dispensers.

    PubMed

    Hummel, Hans E; Langner, S S

    2013-01-01

    Modern insect pest management is faced with an increasingly sophisticated set of requirements. Control agent/dispenser combinations must be at the same time safe, nontoxic, inexpensive, reproducibly efficacious, environmentally compatible, biodegradable, and sustainable, and should be based on renewable resources. The methods employed preferably should be suitable for the growing and tightly controlled organic growing sector as well. All this calls for a level of sophistication and reproducibility previously unknown. Only very few systems can offer this kind of performance, but fortunately can be found in the area of suitable pheromone/dispenser combinations. This report is an attempt to adapt electrospun Ecoflex polyester micro fibers of the Greiner-Wendorff type to the very specific needs of the grape growing industry. Specifically required are "semi-intelligent" dispenser materials. On a weight basis, the electrospun product should achieve as high a proportion as possible of "retainable" sex pheromone (E,Z)-7,9-dodecadienyl acetate of Lobesia botrana (Lep.: Tortricidae) and should release it as uniformly as possible into the surrounding airspace. Using the Doye bioassay, some progress indeed has recently been achieved with electrospun Ecoflex microfibers of 0.5-3.5 microm diameter. They were employed as dispensers for programmed sex pheromone release with an effective mating disruption duration of up to seven weeks. With one microfiber/pheromone treatment, this covers one entire flight period of the trivoltine L. botrana. Mechanical application of this microfiber/pheromone preparation (with the option of automation) is possible. Disruption effects are comparable with those of commercially available dispensers of the Isonet type. Exposed under vineyard conditions, Ecoflex polyester fibers are a spider silk like material which is biodegradable within half a year. Thus, after releasing its pheromone load, it does not need removal, which saves one cultivation step. The fibers are under rigorous quantitative pretesting by analytical lab methods such as scanning EM, CLSA, timed weight loss curves in isothermal wind tunnels, and by thermogravimetry. Grapes produced under protection with these pheromone-charged biodegradable and mechanically deployable Ecoflex microfibers are completely free of pesticide residues. PMID:25145245

  15. An Investigation of Thermal Characteristic of Mechanical Crimp Textured Polyester Yarn by Differential Scanning Calorimeter (DSC)

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Someshwar S.; Shaikh, Tasnim N.; Pratap, Arun

    2010-06-01

    Deficiencies related to the lack of bulk in flat continuous filament yarns make them unsuitable for apparel, home textiles as well as other applications such as car seat covering. Hence, texturising is employed to impart lofty and bulky characteristics to them. The two major texturising techniques employed for polyester yarn are false-twist and air-jet texturising. Out of these earlier technique depends on the thermoplasticity of the yarn being textured whereas the later one demands subsequent amount of compressed air to carry out cold fluid texturising. A new concept of mechanical crimp texturising has been designed to overcome these limitations of commercially successful techniques. In this new technique, pre-twisted FDY (Fully Drawn Yarn) flat multifilament yarn has been subjected to the higher false-twisting (depending on yarn fineness) action under the condition of underfeed (depending on ductility of parent yarn). The torque caused due to high level of false-twisting, forces the filaments to follow helical path at a certain angle (depends on magnitude of twist and denier per filament) to the filament yarn longitudinal axis. Internal stresses arising in single filaments tend to bend the filament and take the shape of spatial helical spring. After the yarn has passed through the false twisting unit, the initial twist would reassert itself and lock the already formed crimpy convolutions in position. Mechanical crimp textured polyester yarns with different pre-twist and false-twist levels have been subjected to thermal stress analysis using differential Scanning Calorimeter (DSC) in heat-cool-heat mode. The samples were heated at a rate of 10°C/minute. Almost all samples appear to be crystalline in nature. However, the melting endotherm does not show sharp peak. Instead, the diffuse nature of the peak is a signature of a partial crystalline nature (48%) of the samples. After melting the specimens, cooling of the same leads to crystallization of the material. This is exhibited by the exotherm. Heating the so-cooled samples, in general, increases their melting point in almost all samples. Thus melting event is shifted towards higher temperature, except for one sample in which pre-twist level is appreciably high. Thus, DSC is a very useful technique to select and optimize the pre-twist level and may provide quite a significant insight into the thermal stability of the mechanical crimp textured yarn.

  16. Fabric Fact & Fiction.

    ERIC Educational Resources Information Center

    Cohen, Andrew

    2001-01-01

    Examines the positive and negative attributes of fabric structures in providing affordable shelter for a variety of multipurpose applications, including temporary or seasonal use. Describes the three basic types of fabric structures: air-supported, frame-supported, and mast-supported. This article focuses on smaller structures of the air- and…

  17. Advanced bacterial polyhydroxyalkanoates: towards a versatile and sustainable platform for unnatural tailor-made polyesters.

    PubMed

    Park, Si Jae; Kim, Tae Wan; Kim, Min Kyung; Lee, Sang Yup; Lim, Sung-Chul

    2012-01-01

    Polyhydroxyalkanoates (PHAs) are biopolyesters that generally consist of 3-, 4-, 5-, and 6-hydroxycarboxylic acids, which are accumulated as carbon and energy storage materials in many bacteria in limited growth conditions with excess carbon sources. Due to the diverse substrate specificities of PHA synthases, the key enzymes for PHA biosynthesis, PHAs with different material properties have been synthesized by incorporating different monomer components with differing compositions. Also, engineering PHA synthases using in vitro-directed evolution and site-directed mutagenesis facilitates the synthesis of PHA copolymers with novel material properties by broadening the spectrum of monomers available for PHA biosynthesis. Based on the understanding of metabolism of PHA biosynthesis, recombinant bacteria have been engineered to produce different types of PHAs by expressing heterologous PHA biosynthesis genes, and by creating and enhancing the metabolic pathways to efficiently generate precursors for PHA monomers. Recently, the PHA biosynthesis system has been expanded to produce unnatural biopolyesters containing 2-hydroxyacid monomers such as glycolate, lactate, and 2-hydroxybutyrate by employing natural and engineered PHA synthases. Using this system, polylactic acid (PLA), one of the major commercially-available bioplastics, can be synthesized from renewable resources by direct fermentation of recombinant bacteria. In this review, we discuss recent advances in the development of the PHA biosynthesis system as a platform for tailor-made polyesters with novel material properties. PMID:22137963

  18. The Influence of impact on Composite Armour System Kevlar-29/polyester-Al2O3

    NASA Astrophysics Data System (ADS)

    Ramadhan, A. A.; Abu Talib, A. R.; Mohd Rafie, A. S.; Zahari, R.

    2012-09-01

    An experimental investigation of high velocity impact responses of composite laminated plates using a helium gas gun has been presented in this paper. The aim of this study was to develop the novel composite structure that meets the specific requirements of ballistic resistance which used for body protections, vehicles and other applications. Thus the high velocity impact tests were performed on composite Kevlar-29 fiber/polyester resin with alumina powder (Al2O3). The impact test was conducted by using a cylindrical steel projectile of 7.62mm diameter at a velocity range of 160-400 m/s. The results (shown in this work) are in terms of varying plate thickness and the amount of energy absorbed by the laminated plates meanwhile we obtained that the 12mm thickness of composite plate suitable for impact loading up to 200m/s impact velocity. Therefore this composite structure (it is used to reduce the amount of Kevlar) considered most economical armoure products. We used the ANSYS AUTODYN 3D- v.12 software for our simulations. The results have been obtained a4.1% maximum errors with experimental work of energy absorption.

  19. Further Study on Chemical Constituents of Parnassia wightiana Wall: Four New Dihydro-?-agarofuran Sesquiterpene Polyesters

    PubMed Central

    Gao, Zhao-Feng; Zhou, Bo-Hang; Zhao, Jie-Yu; Cao, Fang-Jun; Zhou, Le; Geng, Hui-Ling

    2015-01-01

    Four new (1–4), along with six known (5–10) dihydro-?-agarofuran sesquiterpene polyesters were isolated from the whole plants of Parnassia wightiana. The new compounds were structurally elucidated through spectroscopic analysis including UV (Ultraviolet Spectrum), IR (Infrared Spectrum), 1H-NMR (1Hydrogen-Nuclear Magnetic Resonance), 13C-NMR (13Carbon-Nuclear Magnetic Resonance), DEPT (Distortionless Enhancement by Polarization Transfer), 1H-1H COSY (1H-1H Correlation Spectroscopy), HSQC (Heteronuclear Single Quantum Coherence), HMBC (Heteronuclear Multiple Bond Correlation), NOESY (Nuclear Overhauser Enhancement Spectroscopy) and HR-MS (High Resolution Mass Specttrum) and their absolute configurations were proposed by comparison of NOESY spectra and specific optical rotations with those of known compounds and biosynthesis grounds. Compound 2 is the first sesquiterpene alkaloid isolated from this plant. New compounds 1–4 exhibited some cytotoxic activities against NB4, MKN-45 and MCF-7 cells at 20 ?M and of which 4 showed the highest activity against NB4 and MKN-45 cells with inhibition rates of 85.6% and 30.5%, respectively. PMID:25915027

  20. Evaluation of biodegradable polyester-co-lactone microparticles for protein delivery.

    PubMed

    Tawfeek, Hesham M; Khidr, Sayed H; Samy, Eman M; Ahmed, Sayed M; Gaskell, Elsie E; Hutcheon, Gillian A

    2014-09-01

    Abstract Poly(glycerol adipate-co-?-pentadecalactone) (PGA-co-PDL) was previously evaluated for the colloidal delivery of ?-chymotrypsin. In this article, the effect of varying polymer molecular weight (MW) and chemistry on particle size and morphology; encapsulation efficiency; in vitro release; and the biological activity of ?-chymotrypsin (?-CH) and lysozyme (LS) were investigated. Microparticles were prepared using emulsion solvent evaporation and evaluated by various methods. Altering the MW or monomer ratio of PGA-co-PDL did not significantly affect the encapsulation efficiency and overall poly(1,3-propanediol adipate-co-?-pentadecalactone) (PPA-co-PDL) demonstrated the highest encapsulation efficiency. In vitro release varied between polymers, and the burst release for ?-CH-loaded microparticles was lower when a higher MW PGA-co-PDL or more hydrophobic PPA-co-PDL was used. The results suggest that, although these co-polyesters could be useful for protein delivery, little difference was observed between the different PGA-co-PDL polymers and PPA-co-PDL generally provided a higher encapsulation and slower release of enzyme than the other polymers tested. PMID:23855737

  1. Hyperbranched Polyester Hydrogels with Controlled Drug Release and Cell Adhesion Properties

    PubMed Central

    Zhang, Hongbin; Patel, Alpesh; Gaharwar, Akhilesh K.; Mihaila, Silvia M.; Iviglia, Giorgio; Mukundan, Shilpaa; Bae, Hojae; Yang, Huai; Khademhosseini, Ali

    2013-01-01

    Hyperbranched polyesters (HPE) have a high efficiency to encapsulate bioactive agents, including drugs, genes and proteins, due to their globe-like nanostructure. However, the use of these highly branched polymeric systems for tissue engineering applications has not been broadly investigated. Here, we report synthesis and characterization of photocrosslinkable HPE hydrogels with sustained drug release characteristics for cellular therapies. These HPE can encapsulate hydrophobic drug molecules within the HPE cavities, due to the presence of hydrophobic inner structure that is otherwise difficult to achieve in conventional hydrogels. The functionalization of HPE with photocrosslinkable acrylate moieties renders the formation of hydrogels with highly porous interconnected structure, and mechanically tough network. The compressive modulus of HPE hydrogels was tunable by changing the crosslinking density. The feasibility of using these HPE networks for cellular therapies was investigated by evaluating cell adhesion, spreading and proliferation on hydrogel surface. Highly crosslinked and mechanically stiff HPE hydrogels have higher cell adhesion, spreading, proliferation compared to soft and complaint HPE hydrogels. Overall, we showed that hydrogels made from HPE could be used for biomedical applications that require control cell adhesion and control release of hydrophobic clues. PMID:23394067

  2. A Molecular Design to Enhance Toughness of High Tg Glassy Polyesters and Polyestercarbonates

    NASA Astrophysics Data System (ADS)

    Li, Xiangyang; Yee, Albert

    2000-03-01

    Three series of polyesters/polyestercarbonates have been synthesized. Two are based on 3, 3, 3', 3'-tetramethyl-1, 1'-spirobi-indane (SBI) and 4,4'-(3,3,5 trimethylcyclohexylidene)diphenol (Tmc).Both monomers are rigid and bulky, resulting in high T_gs. The other is based on the relatively flexible 4,4'-cyclohexylidene diphenol (BPAZ).Cyclohexylene rings (C-rings) are inserted into the backbones. DMA, positronium annihilation, thermal expansion and tensile tests indicate that chair-boat-chair (C-B-C) conformational transitions of C-rings can couple with their neighbors and enhance local segmental motion, resulting in ductile polymers. The C-B-C motion couples strongly with its neighbors in Tmc_xC, BPAZ_xC and the randomcopolymer of BPA, SBI and cyclohexane dicarboxylic acid (SCBC), where x is the number of monomers in a block. This coupling is especially evident in the BPAZ_xC series of polymers. These results demonstrate that it is possible to design high temperature tough polymers by using a building block approach, viz., high Tg units and mobility enhancing units. This work is funded by AFOSR Grant NO. F49620-98-1-0158.

  3. Glass fibre polyester composite with in vivo vascular channel for use in self-healing

    NASA Astrophysics Data System (ADS)

    Fifo, Omosola; Ryan, Kevin; Basu, Biswajit

    2014-09-01

    The embedment of adhesive-filled hollow glass fibres (HGF) has been reported as a way of combating micro-crack development in fibre-reinforced polymer (FRP) structures. However, hollow fibres can critically undermine the effectiveness of self-healing systems and have been reported to be a potential impediment to the healing agent flow path. On the other hand, attempting to use non-hollow vascular systems in higher dimensions has largely been restricted to bulk polymers that lack reinforcing fibres. This paper investigates an alternative technique where a simple two-dimensional (2D) network of hollow channels is created within a glass-fibre-reinforced polyester-composite structure. The network is created using a fugitive preforming material at the ply level of interest, similar to a direct ink writing procedure. The temporary structure is extracted as a part of the curing and post-curing processes. The channels formed are used to deliver cyanoacrylate adhesive (CA) to areas that have been damaged under a flexural three-point bending test. Subsequent post-repair mechanical testing, under the same mode, evaluates the success of the repair process. The results show good recovery of the stiffness, a paramount mechanical property, and indicate how the grade of the repairing agent used influences the recovered loading strength of the FRP samples.

  4. Chirality Effects on the Morphology and Structure of Synthetic Chiral Main-chain Liquid Crystal Polyesters

    NASA Astrophysics Data System (ADS)

    Weng, X.; Li, C. Y.; Zhang, J. Z.; Bai, F.; Jin, S.; Harris, F. W.; Cheng, S. Z. D.

    2002-03-01

    The main-chain liquid crystal chiral polyesters are synthesized via an A-B type condensation polymerization from (R)-(-)-4'-w-[2-(p-hydroxy-o-nitrophenyloxy)-1-propyloxy]-1-alkyloxy-4- biphenyl carboxylic acid. The resulting polymers, abbreviated as PET(R*-10,11), exhibit multiple chiral liquid crystal phases, including chiral Smectic A* and C* phases, at different temperatures as identified by polarized optical microscopy, differential scanning calorimetry and wide angle X-ray diffraction (WAXD). For PET(R*-11), flat and helical single lamellar crystals have been obtained in the melt crystallization and solvent evaporation. All helical crystals show a right-handed twist with pitch lengths on a micrometer size as observed by transmission electron microscopy and atomic force microscopy. The crystal structures of the flat and helical crystals are determined to be identical (orthorhombic with a=1.03 nm, b=0.47 nm, c=6.43 nm) by electron diffraction and WAXD fiber pattern experiments. Rotation twin crystals in flat geometry are also observed by melt crystallization. Surprisingly, the helical crystals of PET(R*-10) prepared from the similar process are all left-handed. The structure of the flat crystal of PET(R*-10) can be explained as “micro-twin” based on the results of electron diffraction.

  5. Morphological Chirality and Crystal Twinning in Different Length Scales of a Chiral Liquid Crystalline Polyester

    NASA Astrophysics Data System (ADS)

    Weng, Xin; Li, Christopher Y.; Jin, Shi; Zhang, Dong; Zhang, John Z.; Bai, Feng; Harris, Frank W.; Cheng, Stephen Z. D.; Lotz, Bernard

    2003-03-01

    The chiral liquid crystalline polyester is synthesized from (R)-(-)-4'-[2-(p-hydroxy-o-nitrophenyloxy)-1-propyloxy]-1-undecyloxy-4-biphenyl carboxylic acid via an A-B type condensation polymerization. The resulting polymer exhibits Chiral Smectic A, Chiral Smectic C and Twist Grain Boundary Smectic A phases, as indicated by DSC, WAXD and PLM. Helical morphologies exist in the latter two phases. By melt crystallization and solvent evaporation, flat single lamellar crystals have been obtained with a basic monoclinic unit cell with a=1.03nm, b=0.47nm, c=6.43nm and ×=83 by SAED and WAXD fiber pattern. SAED results also showed that two kinds of crystal twinnings existed in this polymer: micro-twinning within one single lamellar crystal and rotation-twinning between two lamellae. Morphological helical structures can also be obtained in the crystal form in this polymer. The helical lamellar crystals possess the same crystal structure as their flat counterparts and all helical crystals show a right-handed twist with pitch lengths on a micrometer size by TEM and AFM.

  6. Synthesis of Unsaturated Polyester Resins from Various Bio-Derived Platform Molecules.

    PubMed

    Farmer, Thomas J; Castle, Rachael L; Clark, James H; Macquarrie, Duncan J

    2015-01-01

    Utilisation of bio-derived platform molecules in polymer synthesis has advantages which are, broadly, twofold; to digress from crude oil dependence of the polymer industry and secondly to reduce the environmental impact of the polymer synthesis through the inherent functionality of the bio-derived platform molecules. Bulk polymerisation of bio-derived unsaturated di-acids has been employed to produce unsaturated polyester (UPEs) which have been analysed by GPC, TGA, DSC and NMR spectroscopy, advancing on the analysis previously reported. UPEs from the diesters of itaconic, succinic, and fumaric acids were successfully synthesised with various diols and polyols to afford resins of MN 480-477,000 and Tg of -30.1 to -16.6 °C with solubilities differing based on starting monomers. This range of properties allows for many applications and importantly due to the surviving Michael acceptor moieties, solubility and cross-linking can be specifically tailored, post polymerisation, to the desired function. An improved synthesis of itaconate and succinate co-polymers, via the initial formation of an itaconate bis-diol, is also demonstrated for the first time, resulting in significantly improved itaconate incorporation. PMID:26147423

  7. Preparation of polyester/gypsum/composite using gamma radiation, and its radiation stability

    NASA Astrophysics Data System (ADS)

    Ajji, Zaki

    2005-06-01

    Composites based on pure gypsum and polyester-styrene resin have been prepared using various doses of gamma radiation. Some physical properties of the prepared composites and the influence of irradiation dose on it have been studied as: compression strength, hardness, thermal decomposition temperature in nitrogen or oxygen, and the change in weight in aqueous solutions with different pH values. The glass transition temperature of the pure polymer and the composites increases with increasing the irradiation dose up to a plateau, and the glass transition temperature of the pure polymer is lower than that of the composites. The irradiation dose does not seem to affect the decomposition temperature of the pure polymer or the composites significantly and the decomposition temperature in presence of nitrogen is higher than that in presence of oxygen. Increasing the irradiation dose leads to an enhancement of the compression strength of the pure polymer and the prepared composites; the hardness of the pure polymer and the composites seems to be constant versus the irradiation dose. Soaking experiments show that the weight of composites does not change in distilled and alkaline medium, but there is a limited decrease in acidic medium of about 3% after 1560 h.

  8. Degradable polyester scaffolds with controlled surface chemistry combining minimal protein adsorption with specific bioactivation

    NASA Astrophysics Data System (ADS)

    Grafahrend, Dirk; Heffels, Karl-Heinz; Beer, Meike V.; Gasteier, Peter; Möller, Martin; Boehm, Gabriele; Dalton, Paul D.; Groll, Jürgen

    2011-01-01

    Advanced biomaterials and scaffolds for tissue engineering place high demands on materials and exceed the passive biocompatibility requirements previously considered acceptable for biomedical implants. Together with degradability, the activation of specific cell-material interactions and a three-dimensional environment that mimics the extracellular matrix are core challenges and prerequisites for the organization of living cells to functional tissue. Moreover, although bioactive signalling combined with minimization of non-specific protein adsorption is an advanced modification technique for flat surfaces, it is usually not accomplished for three-dimensional fibrous scaffolds used in tissue engineering. Here, we present a one-step preparation of fully synthetic, bioactive and degradable extracellular matrix-mimetic scaffolds by electrospinning, using poly(D,L-lactide-co-glycolide) as the matrix polymer. Addition of a functional, amphiphilic macromolecule based on star-shaped poly(ethylene oxide) transforms current biomedically used degradable polyesters into hydrophilic fibres, which causes the suppression of non-specific protein adsorption on the fibres’ surface. The subsequent covalent attachment of cell-adhesion-mediating peptides to the hydrophilic fibres promotes specific bioactivation and enables adhesion of cells through exclusive recognition of the immobilized binding motifs. This approach permits synthetic materials to directly control cell behaviour, for example, resembling the binding of cells to fibronectin immobilized on collagen fibres in the extracellular matrix of connective tissue.

  9. Further Study on Chemical Constituents of Parnassia wightiana Wall: Four New Dihydro-?-agarofuran Sesquiterpene Polyesters.

    PubMed

    Gao, Zhao-Feng; Zhou, Bo-Hang; Zhao, Jie-Yu; Cao, Fang-Jun; Zhou, Le; Geng, Hui-Ling

    2015-01-01

    Four new (1-4), along with six known (5-10) dihydro-?-agarofuran sesquiterpene polyesters were isolated from the whole plants of Parnassia wightiana. The new compounds were structurally elucidated through spectroscopic analysis including UV (Ultraviolet Spectrum), IR (Infrared Spectrum), ¹H-NMR (¹Hydrogen-Nuclear Magnetic Resonance), ¹³C-NMR (¹³Carbon-Nuclear Magnetic Resonance), DEPT (Distortionless Enhancement by Polarization Transfer), ¹H-¹H COSY (¹H-¹H Correlation Spectroscopy), HSQC (Heteronuclear Single Quantum Coherence), HMBC (Heteronuclear Multiple Bond Correlation), NOESY (Nuclear Overhauser Enhancement Spectroscopy) and HR-MS (High Resolution Mass Specttrum) and their absolute configurations were proposed by comparison of NOESY spectra and specific optical rotations with those of known compounds and biosynthesis grounds. Compound 2 is the first sesquiterpene alkaloid isolated from this plant. New compounds 1-4 exhibited some cytotoxic activities against NB4, MKN-45 and MCF-7 cells at 20 ?M and of which 4 showed the highest activity against NB4 and MKN-45 cells with inhibition rates of 85.6% and 30.5%, respectively. PMID:25915027

  10. Antimicrobial electrospun nanofibers of cellulose acetate and polyester urethane composite for wound dressing.

    PubMed

    Liu, Xin; Lin, Tong; Gao, Yuan; Xu, Zhiguang; Huang, Chen; Yao, Gang; Jiang, Linlin; Tang, Yanwei; Wang, Xungai

    2012-08-01

    In this study, a series of nanofibrous membranes were prepared from cellulose acetate (CA) and polyester urethane (PEU) using coelectrospinning or blend-electrospinning. The drug release, in vitro antimicrobial activity and in vivo wound healing performance of the nanofiber membranes were evaluated for use as wound dressings. To prevent common clinical infections, an antimicrobial agent, polyhexamethylene biguanide (PHMB) was incorporated into the electrospun fibers. The presence of CA in the nanofiber membrane improved its hydrophilicity and permeability to air and moisture. CA fibers became slightly swollen upon contacting with liquid phase. CA not only increased the liquid uptake but also created a moist environment for the wound, which accelerated wound recovery. PHMB release dynamics of the membranes was controlled by the structure and component ratios of the membranes. The lower ratio of CA: PEU helped to preserve the physical and thermal properties of the membranes, and also reduced the burst release effectively and slowed down diffusion of PHMB during in vitro tests. The controlled-diffusion membranes exerted long-term antimicrobial effect for wound healing. PMID:22692845

  11. Biodegradable polyester-based microcarriers with modified surface tailored for tissue engineering.

    PubMed

    Privalova, A; Markvicheva, E; Sevrin, Ch; Drozdova, M; Kottgen, C; Gilbert, B; Ortiz, M; Grandfils, Ch

    2015-03-01

    Microcarriers have been proposed in tissue engineering, namely for bone, cartilage, skin, vascular, and central nervous system. Although polyester-based microcarriers have been already used for this purpose, their surface properties should be improved to provide better cell growth. The goal of this study was to prepare microbeads based on poly(D,L-lactide) acid, poly(L-lactide) acid, and to study cell behavior (adhesion, spreading, growth, and proliferation) in function of microbead topography and surface chemistry. To improve L-929 fibroblasts adhesion, microbead surface has been modified with three polycations: chitosan, poly(2-dimethylamino ethylmethacrylate) (PDMAEMA), or chitosan-g-oligolactide copolymer (chit-g-OLA). Although modification of the microbead surface with chitosan and PDMAEMA was performed through physical adsorption on the previously prepared microbeads, chit-g-OLA copolymer was introduced directly during microbead processing. This simple approach (1) bypass the use of an emulsifier (polyvinyl alcohol, PVA); (2) avoid surface "contamination" with PVA molecules limiting a control of the surface characteristics. In vitro study of the growth of mouse fibroblasts on the microbeads showed that both surface topography and chemistry affected cell attachment, spreading, and proliferation. Cultivation of L-929 fibroblasts for 7 days resulted in the formation of a 3D cell-scaffold network. PMID:24832052

  12. Development of Composite Porous Scaffolds Based on Collagen and Biodegradable Poly(ester urethane)urea

    PubMed Central

    Guan, Jianjun; Stankus, John J.; Wagner, William R.

    2010-01-01

    Our objective in this work was to develop a flexible, biodegradable scaffold for cell transplantation that would incorporate a synthetic component for strength and flexibility and type I collagen for enzymatic lability and cytocompatibility. A biodegradable poly(ester urethane)urea was synthesized from poly(caprolactone), 1,4-diisocyanatobutane, and putrescine. Using a thermally induced phase separation process, porous scaffolds were created from a mixture containing this polyurethane and 0%, 10%, 20%, or 30% type I collagen. The resulting scaffolds were found to have open, interconnected pores (from 7 to >100 um) and porosities from 58% to 86% depending on the polyurethane/collagen ratio. The scaffolds were also flexible with breaking strains of 82–443% and tensile strengths of 0.97–4.11 MPa depending on preparation conditions. Scaffold degradation was significantly increased when collagenase was introduced into an incubating buffer in a manner that was dependent on the mass fraction of collagen present in the scaffold. Mass losses could be varied from 15% to 59% over 8 weeks. When culturing umbilical artery smooth muscle cells on these scaffolds higher cell numbers were observed over a 4-week culture period in scaffolds containing collagen. In summary, a strong and flexible scaffold system has been developed that can degrade by both hydrolysis and collagenase degradation pathways, as well as support cell growth. This scaffold possesses properties that would make it attractive for future use in soft tissue applications where such mechanical and biological features would be advantageous. PMID:16826792

  13. Framework effect of amphiphilic polyesters on their molecular movement and protein adsorption-resistance properties.

    PubMed

    Cao, Jun; Cheng, Furong; Cao, Huan; Lu, Aijing; Cai, Mengtan; Chen, Yuanwei; He, Bin; Gu, Zhongwei; Luo, Xianglin

    2015-01-01

    Surface chemical characteristics of biomedical polymers, which are determined by the migration and rearrangement of polymeric chains, play an important role in the protein adsorption. In this work, the relationship between the architectures of amphiphilic polyesters and their protein adsorption resistance was investigated. Three poly (?-caprolactone)s containing sulfobetaines (PCL-b-PDEAS) segments with linear, four arms and six arms star-shaped architectures were synthesized with the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The structures of the amphiphiles were confirmed by (1)H NMR and FTIR. Water contact angles (WCA) and X-ray photoelectron spectroscopy (XPS) were used to study the surface properties of the amphiphilic copolymer films. The water contact angles were decreased due to the surface migration of hydrophilic segments. Transmission electron microscopy (TEM) displayed the occurrence of microphase separation phenomena for PCL-b-PDEAS above glass transition temperature (Tg). The results showed that the hydrophilic segments in the copolymers would migrate to the surface of the films, which resulted in the surface more hydrophilic to resist protein adsorption. The adsorption of both fibrinogen (Fg) and bovine serum albumin (BSA) were studied. The results showed that protein adsorption was depended on not only the hydrophilic chain migration but also the shape of proteins. PMID:25499227

  14. Reinforcement and nucleation of acetylated cellulose nanocrystals in foamed polyester composites.

    PubMed

    Hu, Fei; Lin, Ning; Chang, Peter R; Huang, Jin

    2015-09-20

    The biodegradable foamed nanocomposites were developed from the reinforcement of surface acetylated cellulose nanocrystals (ACNC) as bionanofillers and the poly(butylene succinate) (PBS) as polymeric matrix. The surface modification of high-efficiency acetylation on the cellulose nanocrystals converted the hydrophilic hydroxyl groups to hydrophobic acetyl groups, which improved the compatibility between rigid nanoparticles and polyester matrix through the similar ester groups of two components. With the introduction of 5wt% ACNC, the specific flexural strength (?/?f) and the specific flexural modulus (E/?f) of the foamed composites significantly increased by 75.7% and 57.2% in comparison with those of the neat PBS foamed material. Meanwhile, with the change of the ACNC concentrations, the cell size and cell density of the foamed composites can be regulated and achieved the high cell density of 1.95×10(5)cells/cm(3) bearing the small average cell size of 178.84?m (5wt% ACNC). The microstructure observation of the foamed composites indicated the moderate loading levels of rigid ACNC can serve as the reinforcing phase for the stress transfer and promote the crystallinity advancement of the foamed composites. PMID:26050907

  15. Dyeing and antibacterial activation with methylene blue of a cyclodextrin modified polyester vascular graft.

    PubMed

    Kacem, I; Laurent, T; Blanchemain, N; Neut, C; Chai, F; Haulon, S; Hildebrand, H F; Martel, B

    2014-09-01

    The aim of this study was to develop an antiseptic and blue dyed polyester (PET) vascular graft in order to reach two distinct properties: (i) the prevention of postoperative infections, (ii) the improvement of the graft compatibility with the coelioscopy surgical technique. This work consisted of dyeing a vascular prosthesis with methylene blue (MB) which is known as a cationic dye with antiseptic properties. Therefore, the functionalization of the PET fibers of the prosthesis with a cyclodextrin-citric acid polymer (PolyCD) was achieved in order to improve its sorption capacity. The NMR experiments demonstrated that a 1:2 complex occurred between hydroxypropyl ?-cyclodextrin (HP-?CD) and MB. Kinetic and sorption isotherm studies showed that an impregnation of the polyCD modified prosthesis (PET-CD) in a 1 g L(-1) of MB solution for 150 min was sufficient to reach the saturation of the device. Results proved that the adsorption mechanism followed the Langmuir model and a maximum of 20 mg g(-1) of MB on the graft. A sustained release of MB in batch tests was observed in PBS and in vitro microbiological assays displayed a prolongation of the bactericidal effect of PET-CD whose extent varied with the amount of MB preliminarily adsorbed onto the PET-CD. PMID:24123800

  16. Counterion Dynamics in Polyester-Sulfonate Ionomers with Ionic Liquid Counterions

    SciTech Connect

    Tudryn, Gregory J.; Liu, Wenjuan; Wang, Shih-Wa; Colby, Ralph H. (Penn)

    2012-04-02

    Conventional sodium cations (Na{sup +}) in sulfonated polyester ionomers were replaced with ammonium-based ionic liquid counterions. Counterion dynamics were measured by dielectric spectroscopy and linear viscoelastic response via oscillatory shear. Ion exchange from sodium counterions to ionic liquid counterions such as tetramethylammonium and tetrabutylammonium showed an order of 10{sup 4} increase in conductivity compared with sodium counterions, primarily attributed to weaker ionic interactions that lower the glass transition temperature. Electrode polarization was used in conjunction with the 1953 Macdonald model to determine the number density of conducting counterions and their mobility. Conductivity and mobility exhibit Vogel-Fulcher-Tammann (VFT) temperature dependences and both increased with counterion size. Conducting counterion concentrations showed Arrhenius temperature dependences, with activation energy reduced as counterion size increased. When ether-oxygen was incorporated into the mobile cation structure, self-solvating ability notably increased the conducting ion concentration. Weakened ion pairing interactions prove favorable for fundamental design of single-ion conductors for actuators, as ionic liquid counterions can provide both larger and faster strains, required by such electro-active devices.

  17. A Dynamic Transient Model to Simulate the Time Dependent Pultrusion Process of Glass/Polyester Composites

    NASA Astrophysics Data System (ADS)

    Shokrieh, Mahmood M.; Mahmoud Aghdami, Ashkan

    2011-12-01

    The objective of this paper is to introduce a novel dynamic transient model to simulate the time dependent pultrusion process of glass/polyester composites. The model is able to simulate the resin curing process systematically. The resin curing process is divided in two liquid and gel-solid phases. Physical properties of the resin including resin specific heat, viscosity and thermal conductivity change by altering the resin temperature and the degree of cure. It is shown that in liquid and gel-solid phases, some of the resin physical properties have significant role in heat transfer phenomenon and affect simulation results. The physical and mechanical properties of fibers do not change during the curing process of composites; therefore, an equivalent material is introduced instead of the resin-fiber compound. The model simulates the heat generation during the resin curing process. The degree of cure of the resin, used for the resin viscosity calculation, is an important parameter indicating the final stage of simulation of resin curing process. The components of the model are integrated in a finite element method. As case studies, the process of pultrusion of circular, rectangular and I cross-sections are simulated by the model. The results show that the model is able to simulate the pultrusion process very well.

  18. Predicting the Thermal Conductivity of AlSi/Polyester Abradable Coatings: Effects of the Numerical Method

    NASA Astrophysics Data System (ADS)

    Bolot, Rodolphe; Seichepine, Jean-Louis; Qiao, Jiang Hao; Coddet, Christian

    2011-01-01

    The final target of this study is to achieve a better understanding of the behavior of thermally sprayed abradable seals such as AlSi/polyester composites. These coatings are used as seals between the static and the rotating parts in aero-engines. The machinability of the composite coatings during the friction of the blades depends on their mechanical and thermal effective properties. In order to predict these properties from micrographs, numerical studies were performed with different software packages such as OOF developed by NIST and TS2C developed at the UTBM. In 2008, differences were reported concerning predictions of effective thermal conductivities obtained with the two codes. In this article, a particular attention was paid to the mathematical formulation of the problem. In particular, results obtained with a finite difference method using a cell-centered approach or a nodal formulation allow explaining the discrepancies previously noticed. A comparison of the predictions of the computed effective thermal conductivities is thus proposed. This study is part of the NEWAC project, funded by the European Commission within the 6th RTD Framework programm (FP6).

  19. Insulating polymer concrete. [Perlite or glass nodule aggregates bound together with a polyester resin

    SciTech Connect

    Fontana, J.J.

    1984-04-01

    An insulating polymer concrete (IPC) composite has been developed under contract to the Gas Research Institute for possible use as a dike insulation material at Liquid Natural Gas (LNG) storage facilities. In the advent of an LNG spill into the impounding dike area, the boiloff rate of the LNG can be substantially reduced if the surfaces of the dike are insulated. This increased safety at the LNG facility will tend to reduce the hazardous explosive mixture with atmospheric air in the surrounding region. The dike insulation material must have a low thermal conductivity and be unaffected by environmental conditions. The IPC composites developed consist of perlite or glass nodule aggregates bound together as a closed cell structure with a polyester resin. In addition to low thermal conductivity and porosity, these composites have correspondingly high strengths and, therefore, can carry transient loads of workmen and maintenance equipment. Prefabricated IPC panels have been installed experimentally and at least one utility is currently considering a complete installation at its LNG facility. 4 references, 8 tables.

  20. Synthesis and characterization of thermotropic liquid crystalline polyester/multi-walled carbon nanotube nanocomposites

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyu; Wang, Juanjuan; Zhao, Wenfeng; Zhang, Linwei; Zhong, Xing; Li, Rong; Ma, Jiantai

    2010-01-01

    Thermotropic liquid crystalline polyester (TLCP) was synthesized via low-temperature solution polycondensation from 1,4-Bis(4-Hydroxybenzoyloxy)butane and terephthaloyl dichloride. Polymer nanocomposites based on a small quantity of multi-walled carbon nanotubes (MWNTs) were prepared by in situ polymerization method. The wide-angle X-ray diffraction (WAXD) results suggested that the addition of MWNTs to TLCP matrix did not significantly change the crystal structure of TLCP. The interactions between the molecules of the TLCP host phase and the carbon nanotubes were investigated through Raman spectroscopy investigations. We detected a distinct wave number shift of the radial breathing modes, confirming the carbon nanotubes interacted with the surrounding liquid crystal molecules, most likely through aromatic interactions (?-stacking). The interactions between liquid crystal host and nanotube guests were also evident from a polarizing microscopy (POM) study of the liquid crystal-isotropic phase transition in the proximity of nanotubes. The thermal properties and the morphological properties of the TLCP/MWNTs nanocomposites were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). TGA data demonstrated the addition of a small amount of MWNTs into TLCP matrix could improve the thermal stability of TLCP matrix. DSC results revealed that melt transition temperatures and isotropic transition temperatures of the hybrids were enhanced.

  1. Insulating epoxy/barite and polyester/barite composites for radiation attenuation.

    PubMed

    El-Sarraf, M A; El-Sayed Abdo, A

    2013-09-01

    A trial has been made to create insulating Epoxy/Barite (EP/Brt) (?=2.85 g cm(-3)) and Crosslinked Unsaturated Polyester/Barite (CUP/Brt) (?=3.25 g cm(-3)) composites with radiation attenuation and shielding capabilities. Experimental work regarding mechanical and physical properties was performed to study the composites integrity for practical applications. The properties were found to be reasonable. Radiation attenuation properties have been carried out using emitted collimated beam from a fission (252)Cf (100 µg) neutron source, and the neutron-gamma spectrometer with stilbene scintillator. The pulse shape discriminating (P.S.D) technique based on the zero cross-over method was used to discriminate between neutron and gamma-ray pulses. Thermal neutron fluxes, measured using the BF3 detector and thermal neutron detection system, were used to plot the attenuation relations. The fast neutron macroscopic effective removal cross-section ?R, gamma ray total attenuation coefficient µ and thermal neutron macroscopic cross-section ? have been evaluated. Theoretical calculations have been achieved using MCNP-4C2 code to calculate ?R, µ and ?. Also, MERCSF-N program was used to calculate macroscopic effective removal cross-section ?R. Measured and calculated results have been compared and were found to be in reasonable agreement. PMID:23722071

  2. Chemical and physical degradation of glass fiber reinforced cross-linked polyester immersed in hot water

    SciTech Connect

    Hamada, H.; Maekawa, Z.I. [Kyoto Inst. of Tech. (Japan); Ikuta, N. [Osaka Municipal Technical Research Institute (Japan); Kiyosumi, K. [Sekisui Plant Systems Co., Ltd., Osaka (Japan); Tanimoto, T.; Morii, T. [Shonan Inst. of Tech., Kanagawa (Japan)

    1994-12-31

    This study deals with chemical and physical degradation behavior of randomly oriented E-glass fiber continuous strand mat reinforced cross-linked polyester immersed in hot water at 80 and 95 C. The specimens were immersed in hot water for 3, 10, 30, 100, 300, 1000, 3000 and 4000h. Weight change measurement, three-point bending and infrared measurement were performed for the specimens after the immersion. Changes of the weight gain indicated the Fickian diffusion at early immersion time, and after that, it indicated the non-Fickian diffusion with a gradual progress of debonding between fiber and matrix. This degradation of the interface caused a remarkable increase of the weight loss, which was never observed in neat resin. The bending modulus decreased with increase of the weight gain at early immersion time, however, it kept constant at longer immersion time both at 80 C and at 95 C. The constant modulus level at 80C was higher than that at 95 C. At longer immersion time at 80 C, the modulus decreased again to the same level at 95C. The results of infrared measurement suggested the difference of degradation mechanism between early immersion time and longer immersion time. At early immersion time, the resin changed physically by swelling and extraction of polymer with water penetration. Such differences of degradation affected the reduction of modulus. Moreover, the effect of the debonding at the interface on the modulus was discussed by the finite element analysis by introducing the damage mechanics.

  3. Nonlinear optical properties of chiral polyesters: a joint experimental and theoretical study

    NASA Astrophysics Data System (ADS)

    Biju, Philip; Sreekumar, K.

    2003-10-01

    A series of polyesters containing donor-acceptor ?-conjugated polar segments (4,4'-azobenzene dicarbonyl chloride) and chiral building units [L(+)-diethyl tartrate] in the main chain were synthesized and characterized by spectroscopic (IR, UV-Vis, 1H NMR, 13C NMR), thermal (TG/DTG, DSC), and optical (refractive index, optical rotation techniques). Chiral order was induced with a preferred helical sense to attain noncentrosymmetric ordering of dipoles (polar order) in macroscopic dimensions by chemical synthesis (chemical poling). A comprehensive attempt has been made to correlate the polar order of the polymer chains with the chiral order arising out of a preferred helical sense of the chains. This has been achieved by adopting four different theoretical models and comparing the results with the experimentally observed values of the second order polarizability tensor ?. The models used are (1) Logarithmic Law of Mixing (LLM), (2) the Extended Boundary Condition Method (EBCM), (3) The Random Field Ising Model (RFIM) and (4) Semiempirical Computational Model (SCM). The results of the theoretical predictions are compared with the experimentally determined values of ?.

  4. Thermal properties of poly(urethane-ester-siloxane)s based on hyperbranched polyester

    NASA Astrophysics Data System (ADS)

    Pergal, M. V.; Džunuzovi?, J. V.; Ki?anovi?, M.; Vodnik, V.; Pergal, M. M.; Jovanovi?, S.

    2011-12-01

    Novel polyurethanes (PUs) were synthesized using hydroxy-terminated hyperbranched polyester (BH-20) and 4,4'-methylenediphenyl diisocyanate (MDI) as hard segments and hydroxy-terminated ethylene oxide-poly(dimethylsiloxane)-ethylene oxide triblock copolymer (PDMS-EO) as soft segment, with soft segment content ranging from 30 to 60 wt %. The PUs were synthesized by two-step solution polymerization method. The influence of the soft segment content on the structure, swelling behavior and thermal properties of PUs was investigated. According to the results obtained by swelling measurements, the increase of the hard segment content resulted in the increase of the crosslinking density of synthesized samples. DSC results showed that the glass transition temperatures increase from 36 to 65°C with increasing hard segment content. It was demonstrated using thermogravimetric analysis (TGA) that thermal stability of investigated PUs increases with increase of the soft PDMS-EO content. This was concluded from the temperatures corresponding to the 10 wt % loss, which represents the beginning of thermal degradation of samples.

  5. Shrinkage behavior of low profile unsaturated polyester resins at low temperature and low pressure

    SciTech Connect

    Wen Li; Lee, L.J. [Ohio State Univ., Columbus, OH (United States)

    1996-12-31

    In order to achieve excellent surface quality and dimension control of molded polymer composites, low profile additives (LPA) are widely used in low shrinkage unsaturated polyester (UPE) molding compound. Although the detailed LPA mechanism is still a subject of controversy, it is now generally agreed that the most important factor for the low profile behavior is the strong phase separation between LPA and UPE resin during curing. Among the extensive studies of LPA mechanism, most of the work focused on the reaction at high temperatures, since LPAs found most of their applications in high temperature and high pressure processes like sheet molding compound (SMC) and bulk molding compound (BMC). Recently, because of the growing interests of new processes such as low pressure SMC and vacuum infusion resin transfer molding, low shrinkage molding compound with the ability to be processed at low temperature and low pressure have attracted considerable attention from the composite industry. Therefore, further understanding of the low profile mechanism at low temperature and low pressure cure is necessary. Moreover, the relatively long reaction time at low temperature cure provides an opportunity to decouple the factors such as phase separation and microvoid formation, which occur almost at the same time in high temperature cure. The objective of this study is to determine LPA performance as well as to provide a better understanding of low profile mechanism at low temperature and low pressure.

  6. Preparation of thermosensitive membranes by radiation grafting of acrylic acid/ N-isopropyl acrylamide binary mixture on PET fabric

    NASA Astrophysics Data System (ADS)

    Gupta, Bhuvanesh; Mishra, Swaiti; Saxena, Shalini

    2008-05-01

    Thermosensitive membranes were prepared by radiation-induced graft copolymerization of monomers on PET fabrics. A binary mixture of N-isopropyl acrylamide (NIPAAm) and acrylic acid (AA) was grafted on polyester fabric as a base material to introduce thermosensitive poly( N-isopropyl acrylamide) pendant chains having LCST slightly higher than 37 °C in the membrane. The influence of ferrous sulfate, radiation dose and monomer composition on the degree of grafting was studied. The structure of the grafted fabric was characterized by thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy. The thermosensitive nature of the fabric was monitored by swelling at different temperatures. The graft copolymerization of AA with NIPAAm enhanced the LCST of the resultant membrane to ˜37 °C. The moisture vapor transmission rate (MVTR) and air permeability of the fabric decreased slightly, may be due to the slight blocking of the fabric pores. The immobilization of tetracycline hydrochloride as the model drug and its release characteristics at different temperatures were monitored.

  7. New polymorphous computing fabric.

    SciTech Connect

    Wolinski, C. (Christophe); Gokhale, M. (Maya); McCabe, K. P. (Kevin P.)

    2002-01-01

    This paper introduces a new polymorphous computing Fabric well suited to DSP and Image Processing and describes its implementation on a Configurable System on a Chip (CSOC). The architecture is highly parameterized and enables customization of the synthesized Fabric to achieve high performance for a specific class of application. For this reason it can be considered to be a generic model for hardware accelerator synthesis from a high level specification. Another important innovation is the Fabric uses a global memory concept, which gives the host processor random access to all the variables and instructions on the Fabric. The Fabric supports different computing models including MIMD, SPMD and systolic flow and permits dynamic reconfiguration. We present a specific implementation of a bank of FIR filters on a Fabric composed of 52 cells on the Altera Excalibur ARM running at 33 MHz. The theoretical performance of this Fabric is 1.8 GMACh. For the FIR application we obtain 1.6 GMAC/s real performance. Some automatic tools have been developed like the tool to provide a host access utility and assembler.

  8. Covering Walls With Fabrics

    E-print Network

    Anonymous,

    1979-01-01

    fabrics to walls: Permanent Methods ? Adhesive paste or glue Temporary Methods ? Shirring ? Double-stick tape ? Fabric closure tape ? Staple, tack or nail ? Starch Permanent Application Fabrics are permanently installed by gluing them... the wall. Use a level to be sure the trim is straight. Angle the remaining fab ric and attach to the ceiling. Additional trim may be used at the end of the hem (see Figure 8). Figure 8 Padded Wall To pad a wall, staple up to 3 layers of batting used...

  9. Use of polyester monofilaments in the connecting locks of drying screens — “clothing” for paper machines

    Microsoft Academic Search

    A. N. Mogil'nyi

    1999-01-01

    Different types of frames for joining the ends of drying screens — “clothing” for paper machines were analyzed. A structure\\u000a for connecting frames for modern fabric drying screens which totally correspond to the technological and service requirements\\u000a was developed. The optimum types of connecting frames for drying screens include the end segments of the screen fabric forming\\u000a the sewn flap

  10. POLYURETHANE RESINS-TREATED WOOD PALLETS WHICH ARE DECONTAMINABLE OF CHEMICAL WARFARE AGENTS

    Microsoft Academic Search

    D. D. Nicholas; Moon G. Kim; C. U. Pittman Jr; T. P. Schultz; L. L. Ingram Jr; F. R. A. Kabir; L. Wasson; L. Wang; M. Ivankoe

    2001-01-01

    Wood pallets manufactured by impregnating and coating wood with selected polyurethane resins performed comparably to steel control pallets in decontamination of major chemical warfare agents before and after being subjected to various rough-handling and strength test procedures. Cost calculations showed that the wood pallets would be competitive with steel pallets. See Ref. [1].

  11. Biologically inspired digital fabrication

    E-print Network

    Han, Sarah (Sarah J.)

    2013-01-01

    Objects and systems in nature are models for the practice of sustainable design and fabrication. From trees to bones, natural systems are characterized by the constant interplay of creation, environmental response, and ...

  12. Superabsorbent Multilayer Fabric

    NASA Technical Reports Server (NTRS)

    Coreale, J. V.; Dawn, F. S.

    1982-01-01

    Material contains gel-forming polymer and copolymer that absorb from 70 to 200 times their weight of liquid. Superabsorbent Polymer and Copolymer form gels to bind and retain liquid in multiply fabric. Until reaction between liquid and absorbent masses forms gel, backing layer retains liquids within fabric; also allows material to "breathe." Possible applications include baby diapers, female hygiene napkins, and hospital bedpads. Might also have uses in improvement of dry soil.

  13. Superamphiphilic Janus fabric.

    PubMed

    Lim, Ho Sun; Park, Song Hee; Koo, Song Hee; Kwark, Young-Je; Thomas, Edwin L; Jeong, Youngjin; Cho, Jeong Ho

    2010-12-21

    Janus fabrics with superamphiphilicity were fabricated via electrospinning of polyacrylonitrile (PAN). PAN nanofibrous mats were formed on an aluminum foil substrate and then thermally treated to cause hydrolysis. An identical PAN solution was subsequently electrospun onto the hydrolyzed PAN layer, followed by peeling off of the bicomposite film from the collector substrate to produce a free-standing Janus fabric. On one side, the electrospun PAN mat exhibited superhydrophobic properties, with a water contact angle of 151.2°, whereas the initially superhydrophobic PAN sheet on the opposite side of the fabric was converted to a superhydrophilic surface (water contact angle of 0°) through hydrolysis of the surface functional groups induced by the thermal treatment. The resulting Janus fabrics exhibited both superhydrophobicity, repelling water on the one side, and superhydrophilicity, absorbing water on the other side. The organic solvent resistance of the PAN nanofibrous sheets was remarkably improved by incorporation of a tetraethyl orthosilicate. This facile and simple technique introduces a new route for the design and development of functional smart, robust fabrics from an inexpensive, commercially available polymer. PMID:21073162

  14. Contribution To Degradation Study, Behavior Of Unsaturated Polyester Resin Under Neutron Irradiation

    SciTech Connect

    Abellache, D.; Lounis, A.; Taiebi, K. [Laboratory of Sciences and Material Engineering, Faculty of Mechanical Engineering and Chemical Engineering. U.S.T.H.B, BP32 El Alia, Algiers (Algeria)

    2010-01-05

    Applications of unsaturated polyester thermosetting resins are numerous in construction sector, in transport, electric spare parts manufactures, consumer goods, and anticorrosive materials. This survey reports the effect of thermosetting polymer degradation (unsaturated polyester): degradation by neutrons irradiation. In order to evaluate the deterioration of our material, some comparative characterizations have been done between standard samples and damaged ones. Scanning electron microscopy (SEM), ultrasonic scanning, hardness test (Shore D) are the techniques which have been used. The exposure to a neutrons flux is carried out in the column of the nuclear research reactor of Draria (Algiers-Algeria). The energetic profile of the incidental fluxes is constituted of fast neutrons (PHI{sub R} = 3.10{sup 12} n.cm{sup -2}.s{sup -1}, E = 2 Mev) of thermal neutrons (PHI{sub TH} = 10{sup 13} n.cm{sup -2}.s{sup -1}; E = 0.025 ev) and epithermal neutrons (PHI{sub epi} = 7.10{sup 11} n.cm{sup -2}.s{sup -1}; E>4,9 ev). The received dose flow is 0,4 Kgy. We notice only a few scientific investigations can be found in this field. In comparison with the standard sample (no exposed) it is shown that the damage degree is an increasing process with the exposure. Concerning the description of irradiation effects on polymers, we can advance that several reactions are in competition: reticulation, chain break, and oxidation by radical mechanism. In our case the incidental particle of high energy fast neutrons whose energy is greater or equal to 2 Mev, is braked by the target with a nuclear shock during which the incidental particle transmits a part of its energy to an atom. If the energy transfer is sufficient, the nuclear shock permits to drive out an atom of its site the latter will return positioning interstitially, the energy that we used oversteps probably the energy threshold (displacement energy). This fast neutrons collision with target cores proceeds to an indirect ionization by the preliminary creation of excited secondary species that will generate ionization. Scanning electron microscopy (SEM) performed with an acceleration tension of 0,7 kV shows clearly the caused damage. This observation seems to indicate the presence of major chain breaks for the sample bombarded during 90 minutes. Let us note that the presence of benzenic cores improves behavior toward radiations indeed the chemical function recognized as the most stable to radiations is the aromatic ring. In order to value the rigidity of our material we have determined the Young's modulus . The values are 7.17, 7.60, 8.39 and 8.96 Gpa respectively for blank samples, 30, 60 and 90 minutes exposure ones. Thus, we remark an increase of Young's modulus that can be interpreted in terms of reticulation, provided to use the level of irradiation dose.

  15. Encapsulation of docetaxel in oily core polyester nanocapsules intended for breast cancer therapy

    NASA Astrophysics Data System (ADS)

    Youm, Ibrahima; Yang, Xiao Yan; Murowchick, James B.; Youan, Bi-Botti C.

    2011-12-01

    This study is designed to test the hypothesis that docetaxel [Doc] containing oily core nanocapsules [NCs] could be successfully prepared with a high percentage encapsulation efficiency [EE%] and high drug loading. The oily core NCs were generated according to the emulsion solvent diffusion method using neutral Labrafac CC and poly( d, l-lactide) [PLA] as oily core and shell, respectively. The engineered NCs were characterized for particle mean diameter, zeta potential, EE%, drug release kinetics, morphology, crystallinity, and cytotoxicity on the SUM 225 breast cancer cell line by dynamic light scattering, high performance liquid chromatography, electron microscopies, powder X-ray diffraction, and lactate dehydrogenase bioassay. Typically, the formation of Doc-loaded, oily core, polyester-based NCs was evidenced by spherical nanometric particles (115 to 582 nm) with a low polydispersity index (< 0.05), high EE% (65% to 93%), high drug loading (up to 68.3%), and a smooth surface. Powder X-ray diffraction analysis revealed that Doc was not present in a crystalline state because it was dissolved within the NCs' oily core and the PLA shell. The drug/polymer interaction has been indeed thermodynamically explained using the Flory-Huggins interaction parameters. Doc release kinetic data over 144 h fitted very well with the Higuchi model ( R 2 > 0.93), indicating that drug release occurred mainly by controlled diffusion. At the highest drug concentration (5 ?M), the Doc-loaded oily core NCs (as a reservoir nanosystem) enhanced the native drug cytotoxicity. These data suggest that the oily core NCs are promising templates for controlled delivery of poorly water soluble chemotherapeutic agents, such as Doc.

  16. MtgA Deletion-Triggered Cell Enlargement of Escherichia coli for Enhanced Intracellular Polyester Accumulation

    PubMed Central

    Kadoya, Ryosuke; Matsumoto, Ken’ichiro; Ooi, Toshihiko; Taguchi, Seiichi

    2015-01-01

    Bacterial polyester polyhydroxyalkanoates (PHAs) have been produced in engineered Escherichia coli, which turned into an efficient and versatile platform by applying metabolic and enzyme engineering approaches. The present study aimed at drawing out the latent potential of this organism using genome-wide mutagenesis. To meet this goal, a transposon-based mutagenesis was carried out on E. coli, which was transformed to produce poly(lactate-co-3-hydroxybutyrate) from glucose. A high-throughput screening of polymer-accumulating cells on Nile red-containing plates isolated one mutant that produced 1.8-fold higher quantity of polymer without severe disadvantages in the cell growth and monomer composition of the polymer. The transposon was inserted into the locus within the gene encoding MtgA that takes part, as a non-lethal component, in the formation of the peptidoglycan backbone. Accordingly, the mtgA-deleted strain E. coli JW3175, which was a derivate of superior PHA-producing strain BW25113, was examined for polymer production, and exhibited an enhanced accumulation of the polymer (7.0 g/l) compared to the control (5.2 g/l). Interestingly, an enlargement in cell width associated with polymer accumulation was observed in this strain, resulting in a 1.6-fold greater polymer accumulation per cell compared to the control. This result suggests that the increase in volumetric capacity for accumulating intracellular material contributed to the enhanced polymer production. The mtgA deletion should be combined with conventional engineering approaches, and thus, is a promising strategy for improved production of intracellularly accumulated biopolymers. PMID:26039058

  17. Phase Transitions, Crystallization Behaviors and Structure of a Nonracemic Chiral Main-Chain Liquid Crystalline Polyester

    NASA Astrophysics Data System (ADS)

    Jin, Shi; Bai, Feng; Li, Christopher Y.; Harris, Frank W.; Cheng, S. Z. D.

    2002-03-01

    A nonracemic chiral main-chain liquid crystalline (LC) polyester [PET(R*)-7] has been synthesized using condensation reaction of an AB type monomer. Multiple phase transitions have been found during cooling and heating at different rates in differential scanning calorimetry measurements. Wide-angle X-ray diffraction (WAXD) experiments have shown that the phase transition swquence is from a highly ordered smectic phase -SmC* (139 °C) - SmA* (199 °C) TGBA ( 206 °C) isotropic with increasing temperature. Flat-on and twisted helical single crystals can be grown thermotropically from the LC state. Both types of crystals possess the identical monoclinic unit cell: a = 1.04 nm, b = 0.450 nm, c= 5.59 nm and g = 84.2 °. All helical crystals show a right-hand twist with pitch lengths of ranging between 0.5 - 5 mm. These single crystals can also be obtained by evaporating solvent from solution. PET(R*)-7 crystallizes much faster in its orientated form. It has been found that the orientation of crystals can be manipulated by the nature of phase from which they grow. The c-axis of crystals is along the fiber axis when crystallization occurs in the SmA* phase, while the c-axis of crystals is along the direction of the SmC* layer normal when crystallization takes place in the SmC* phase. An interesting observation is that macroscopic LC quasi-monodomains can be obtained by applying a mechanical external field. Detailed WAXD results indicate that they are SmC* quasi-monodomains. A quasi-monodomain can crystallize into a single-crystal-like structure.

  18. Encapsulation of docetaxel in oily core polyester nanocapsules intended for breast cancer therapy

    PubMed Central

    2011-01-01

    This study is designed to test the hypothesis that docetaxel [Doc] containing oily core nanocapsules [NCs] could be successfully prepared with a high percentage encapsulation efficiency [EE%] and high drug loading. The oily core NCs were generated according to the emulsion solvent diffusion method using neutral Labrafac CC and poly(d, l-lactide) [PLA] as oily core and shell, respectively. The engineered NCs were characterized for particle mean diameter, zeta potential, EE%, drug release kinetics, morphology, crystallinity, and cytotoxicity on the SUM 225 breast cancer cell line by dynamic light scattering, high performance liquid chromatography, electron microscopies, powder X-ray diffraction, and lactate dehydrogenase bioassay. Typically, the formation of Doc-loaded, oily core, polyester-based NCs was evidenced by spherical nanometric particles (115 to 582 nm) with a low polydispersity index (< 0.05), high EE% (65% to 93%), high drug loading (up to 68.3%), and a smooth surface. Powder X-ray diffraction analysis revealed that Doc was not present in a crystalline state because it was dissolved within the NCs' oily core and the PLA shell. The drug/polymer interaction has been indeed thermodynamically explained using the Flory-Huggins interaction parameters. Doc release kinetic data over 144 h fitted very well with the Higuchi model (R2 > 0.93), indicating that drug release occurred mainly by controlled diffusion. At the highest drug concentration (5 ?M), the Doc-loaded oily core NCs (as a reservoir nanosystem) enhanced the native drug cytotoxicity. These data suggest that the oily core NCs are promising templates for controlled delivery of poorly water soluble chemotherapeutic agents, such as Doc. PMID:22168815

  19. Development and Evaluation of Novel Coupling Agents for Kenaf-Fiber-Reinforced Unsaturated Polyester Composites

    NASA Astrophysics Data System (ADS)

    Ren, Xiaofeng

    Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a 40% market share of all the thermoset composites. This widespread application is due to many favorable characteristics including low cost, ease of cure at room temperature, ease of molding, a good balance of mechanical, electrical and chemical properties. One of the barriers for the full utilization of the kenaf fiber reinforced UPE composites, however, is the poor interfacial adhesion between the natural fibers and the UPE resins. The good interfacial adhesion between kenaf fibers and UPE matrix is essential for generating the desired properties of kenaf-UPE composites for most of the end applications. Use of a coupling agent is one of the most effective ways of improving the interfacial adhesion. In this study, six novel effective coupling agents were developed and investigated for kenaf-UPE composites: DIH-HEA, MFA, NMA, AESO-DIH, AESO-MDI, and AESO-PMDI. All the coupling agents were able to improve the interfacial adhesion between kanaf and UPE resins. The coupling agents were found to significantly enhance the flexural properties and water resistance of the kenaf-UPE composites. Fourier transform infrared spectroscopy (FTIR) confirmed all the coupling agents were covalently bonded onto kenaf fibers. Scanning electron microscopy (SEM) images of the composites revealed the improved interfacial adhesion between kanaf fibers and UPE resins.

  20. Surface engineering of a cutinase from Thermobifida cellulosilytica for improved polyester hydrolysis.

    PubMed

    Herrero Acero, Enrique; Ribitsch, Doris; Dellacher, Anita; Zitzenbacher, Sabine; Marold, Annemarie; Steinkellner, Georg; Gruber, Karl; Schwab, Helmut; Guebitz, Georg M

    2013-10-01

    Modeling and comparison of the structures of the two closely related cutinases Thc_Cut1 and Thc_Cut2 from Thermobifida cellulosilytica DSM44535 revealed that dissimilarities in their electrostatic and hydrophobic surface properties in the vicinity to the active site could be responsible for pronounced differences in hydrolysis efficiencies of polyester (i.e., PET, polyethyleneterephthalate). To investigate this hypothesis in more detail, selected amino acids of surface regions outside the active site of Thc_Cut2, which hydrolyzes PET much less efficiently than Thc_Cut1 were exchanged by site-directed mutagenesis. The mutants were expressed in E. coli BL21-Gold(DE3), purified and characterized regarding their specific activities and kinetic parameters on soluble substrates and their ability to hydrolyze PET and the PET model substrate bis(benzoyloxyethyl) terephthalate (3PET). Compared to Thc_Cut2, mutants carrying Arg29Asn and/or Ala30Val exchanges showed considerable higher specific activity and higher kcat /KM values on soluble substrates. Exchange of the positively charged arginine (Arg19 and Arg29) located on the enzyme surface to the non-charged amino acids serine and asparagine strongly increased the hydrolysis activity for 3PET and PET. In contrast, exchange of the uncharged glutamine (Glu65) by the negatively charged glutamic acid lead to a complete loss of hydrolysis activity on PET films. These findings clearly demonstrate that surface properties (i.e., amino acids located outside the active site on the protein surface) play an important role in PET hydrolysis. PMID:23592055

  1. Tensile and Adhesion Properties of Metal Thin Films Deposited onto Polyester Film Substrate Prepared by a Conventional Vacuum Evaporator

    NASA Astrophysics Data System (ADS)

    Kita, Takuya; Saitoh, Shou; Iwamori, Satoru

    Four kinds of metal, such as aluminum, copper, indium and tin, thin films were deposited onto polyester (PET) substrate by a conventional vacuum evaporator and evaluated their tensile and adhesion properties. The tensile property was estimated by observations of micro-cracks of the thin films due to the tensile test at 150°C. The tensile property of the metal thin films seems to relate with Brinell hardness and thickness of the thin film. The adhesion property of these metal thin films was estimated by measuring the pull strength. Aluminum thin film showed highest pull strength of all the thin films, and the pull strength increased with increase of the thickness.

  2. Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy- Efficient Wood-Plastic Composites

    SciTech Connect

    Thompson, David N.; Emerick, Robert W.; England, Alfred B.; Flanders, James P.; Loge, Frank J.; Wiedeman, Katherine A.; Wolcott, Michael P.

    2010-03-31

    In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered Wood Products (EWP). Utilizing bio-based thermoplastics for these materials can reduce our dependence on foreign petroleum. We have demonstrated that biopolymers (polyhydroxyalkanoates, PHA) can be successfully produced from wood pulping waste streams and that viable wood fiber reinforced thermoplastic composite products can be produced from these materials. The results show that microbial polyester (PHB in this study) can be extruded together with wastewater-derived cell mass and wood flour into deck products having performance properties comparable to existing commercial HDPE/WF composite products. This study has thus proven the underlying concept that the microbial polyesters produced from waste effluents can be used to make cost-effective and energy-efficient wood-plastic composites. The cost of purified microbial polyesters is about 5-20 times that of HDPE depending on the cost of crude oil, due to high purification (40%), carbon substrate (40%) and sterilized fermentation (20%) costs for the PHB. Hence, the ability to produce competitive and functional composites with unpurified PHA-biomass mixtures from waste carbon sources in unsterile systems—without cell debris removal—is a significant step forward in producing competitive value-added structural composites from forest products residuals using a biorefinery approach. As demonstrated in the energy and waste analysis for the project, significant energy savings and waste reductions can also be realized using this approach. We recommend that the next step for development of useful products using this technology is to scale the technology from the 700-L pilot reactor to a small-scale production facility, with dedicated operation staff and engineering controls. In addition, we recommend that a market study be conducted as well as further product development for construction products that will utilize the unique properties of this bio-based material.

  3. Synthesis and thermal properties of new polyester based on indane-1,3-diol and terephtaloyl chloride

    Microsoft Academic Search

    H. Guemmour; F. Carrière; A. Benaboura

    2001-01-01

    SUMMARY  \\u000a New aromatic polyester was synthetized by polycondensation of indane-1,3-diol and terephthaloyl chloride. The indane-1,3-diol\\u000a was synthesised by metal hydride reduction and characterized by IR, 1H and 13C NMR. Two polycondensation methods was used : solution and interfacial polycondensation in presence of various quaternary\\u000a ammonium salts. The obtained polymers were characterized by differential scanning calorimetry (DSC) and viscosities measurements.\\u000a All

  4. MERIT Hg System Fabrication Status

    E-print Network

    McDonald, Kirk

    metal secondary tube · Original design was SS316, but fabrication issues (welding SS to Ti6Al4V) leading towards all titanium fabrication · Discussions underway with Ti fabricator regarding design details · Fab be fabricated by Princeton · Converting target module to an all-titanium configuration · Current schedule

  5. Delamination of woven E-glass fabric composites

    SciTech Connect

    Dunn, M.L. [Colorado Univ., Boulder, CO (United States). Dept. of Mechanical Engineering; Reedy, E.D. Jr.; Guess, T.R. [Sandia National Labs., Albuquerque, NM (United States)

    1993-11-01

    An experimental/analytical study investigating delamination growth in E-glass fabric/polyester composites has been carried out. Double cantilever beam and end-notched flexure delamination specimens were tested and the measured data was compared to calculated results. A stacked shell finite element methodology has been developed to perform the analysis. This approach breaks the composite into sublaminate shells connected by springs spanning the delamination plane. The stacked shell analyses can use either a critical stress or a critical energy release rate criterion to propagate the delamination, and both criteria are shown to yield similar predictions. Role of connecting springs, and proper choice for spring constants has also been investigated in detail. The spring constants must be chosen in a physically meaningful way to develop consistent values of energy release rate, compliance, and the stress distribution ahead of the delamination. Calculated results for the double cantilever beam and end-notched flexure specimens are in good agreement with measured test data and continuum finite element solutions.

  6. Rapid fabrication of microcomponents

    NASA Astrophysics Data System (ADS)

    Hanemann, Thomas; Hausselt, Juergen H.; Ruprecht, Robert; Skrifvars, M.; Zum Gahr, K.-H.; Pfleging, Wilhelm

    2000-04-01

    In the macroscopic world different 'rapid'-technologies like Rapid Prototyping, Rapid Manufacturing or Rapid Tooling have been established for a fast prototype or molding tool development. In all cases CAD-data can be transformed in a model or prototype directly using a laser which polymerizes reactive resin layer by layer to a final 3D mold within a short period. In this work the rapid fabrication of micro components made from polymers or composites will be presented. The whole fabrication process is divided into two main steps: Firstly laser assisted micro machining using Nd:YAG and KrF-Excimer laser allows a rapid manufacturing of micro structured cemented carbide or steel mold inserts. Secondly the application of light induced reaction injection molding using reactive monomer/polymer resins gives access to the replication of the previously fabricated mold insert. The total processing period starting from CAD until the modeled micro structured part is less than one week.

  7. Primary Implantation of Polyester-Covered Stent-Grafts for Transjugular Intrahepatic Portosystemic Stent Shunts (TIPSS): A Pilot Study

    SciTech Connect

    Cejna, Manfred; Thurnher, Siegfried [Department of Angiography and Interventional Radiology, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Pidlich, Johann [Department of Gastroenterology and Hepatology, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Kaserer, Klaus [Department of Clinical Pathology, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Schoder, Maria; Lammer, Johannes [Department of Angiography and Interventional Radiology, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    1999-07-15

    Purpose: To investigate whether placement of a polyester-covered stent-graft increases the primary patency of transjugular intrahepatic portosystemic stent shunts (TIPSS). Methods: Between 1995 and 1997 Cragg Endopro or Passager MIBS stent-grafts were used for the creation of TIPSS in eight male patients, 35-59 years of age (mean 48 years). All patients suffered from recurrent variceal bleeding and/or refractory ascites due to liver cirrhosis. Seven stent-grafts were dilated to a diameter of 10 mm, one to 12 mm. Follow-up was performed with duplex ultrasound, clinical assessment, and angiography. Results: The technical success rate for creation of a TIPSS was 100%. The mean portosystemic pressure gradient decreased from 25 mmHg to 12 mmHg. In seven of eight patients TIPSS dysfunction occurred between 2 days and 3 years after stent-graft placement. In one patient the TIPSS is still primarily patent (224 days after creation). The secondary patency rates are 31 days to 3 years. Conclusion: The primary use of polyester-covered stent-grafts for TIPSS did not increase primary patency rates in our small series.

  8. 5-Fluorouracil-lipid conjugate: potential candidate for drug delivery through encapsulation in hydrophobic polyester-based nanoparticles.

    PubMed

    Ashwanikumar, N; Kumar, Nisha Asok; Nair, S Asha; Kumar, G S Vinod

    2014-11-01

    The encapsulation of 5-fluorouracil (5-FU) in hydrophobic polymeric materials is made feasible by a lipid-based prodrug approach. A lipid-5-FU conjugate of 5-FU with palmitic acid was synthesized in two-step process. A synthesized dipalmitoyl derivative (5-FUDIPAL) was characterized using Fourier transform infrared spectroscopy and (1)H-nuclear magnetic resonance. The 5-FUDIPAL was encapsulated in polyester-based polymers by the double emulsion-solvent evaporation method. The nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy and dynamic light scattering. The thermal stability was assessed by differential scanning calorimetry data. In vitro release kinetics measurements of the drug from nanoparticles showed the controlled release pattern over a period of time. Cytotoxicity measurements by MTT assay confirmed that dipalmitoyl derivative in nano formulation successfully inhibited the cell growth. Thus the combined physical and biological evaluation of the different polyester-based nanoparticle containing the modified drug showed a facile approach to delivering 5-FU to the tumour site with enhanced efficacy. PMID:25110286

  9. Synthesis of new phosphorus-containing (co)polyesters using solid-liquid phase transfer catalysis and product characterization.

    PubMed

    Iliescu, Smaranda; Augusti, Maite-Gyl; Fagadar-Cosma, Eugenia; Plesu, Nicoleta; Fagadar-Cosma, Gheorghe; Macarie, Lavinia; Popa, Adriana; Ilia, Gheorghe

    2012-01-01

    This paper is directed towards the development of safe, and thermally stable solid polymer electrolytes. Linear phosphorus-containing (co)polyesters are described, including their synthesis, thermal analysis, conductivity, and non-flammability. Polycondensation of phenylphosphonic dichloride (PPD) with poly(ethylene glycol) (PEG 12000) with and without bisphenol A (BA) was carried out using solid-liquid phase transfer catalysis. Potassium phosphate is used as base. Yields in the range of 85.0-88.0%, and inherent viscosities in the range of 0.32-0.58 dL/g were obtained. The polymers were characterized by gel permeation chromatography, FT-IR, (1)H- and (31)P-NMR spectroscopy and thermal analysis. Their flammability was investigated by measuring limiting oxygen index values. The polymers are flame retardants and begin to lose weight in the 190 °C-231 °C range. Solid phosphorus- containing (co)polyesters were complexed with lithium triflate and the resulting ionic conductivity was determined. Conductivities in the range of 10(-7)-10(-8) S cm(-1) were obtained. PMID:22850325

  10. A Corethane/polyester composite vascular prosthesis for vascular access. Comparison with expanded polytetrafluoroethylene grafts in a canine model.

    PubMed

    Wilson, G J; MacGregor, D C; Bridgeman, J; Weber, B A; Binnington, A G; Pinchuk, L

    1995-01-01

    An important need in hemodialysis is a self-sealing prosthesis for vascular access with at least equivalent patency and biostability to expanded polytetrafluoroethylene (ePTFE) alternatives. The authors have developed a Corethane/polyester composite (CPC) graft with an inner blood interfacing layer of spun Corethane fibers (10-15 microns diameter; pore size 30-60 microns) impregnated with a gelatin-heparin complex and an outer soft tissue interfacing warp-knitted polyester sheath. Twenty-six CPC grafts (6 mm internal diameter; 25-30 cm length) and eight Gore-Tex ePTFE grafts (same dimensions) were implanted as femoral artery-to-vein shunts in dogs on low dose (162 mg/day) aspirin, and subjected to weekly dialysis needle punctures for up to 52 weeks. Patency was 73% (19/26 with 15 at 52 weeks) for the CPC grafts and 63% (5/8 at 52 weeks) for the ePTFE controls, with more favorable healing (e.g., less extensive mural thrombi) of the CPC grafts. The hemostasis time per needle pair after removal (3.1 min mean for CPC versus 21.2 min mean for ePTFE) and the blood loss in achieving hemostasis (5.7 g mean for CPC versus 47.9 g for ePTFE) documented the significant (p < 0.0001) performance advantages of the CPC prosthesis. PMID:8573903

  11. Other Fabric Structures

    NASA Technical Reports Server (NTRS)

    1985-01-01

    There are two kinds of fabric structures - tension, supported by cables and pylons, and those supported by air pressure within an enclosed fabric envelope. They are becoming increasingly popular with architects, engineers, etc., because of their aesthetic appeal, low cost and maintenance, energy efficiency and good space utilization. The Structo-Fab roof weighs only 1/30 as much as a conventional roof of that size. Giant fans are used to blow air into the envelope between the roof's outer membrane and its inner liner automatically maintaining the pressure differential necessary for roof rigidity.

  12. In Situ Fabrication Technologies

    NASA Technical Reports Server (NTRS)

    Rolin, Terry D.; Hammond, Monica

    2005-01-01

    A manufacturing system is described that is internal to controlled cabin environments which will produce functional parts to net shape with sufficient tolerance, strength and integrity to meet application specific needs such as CEV ECLS components, robotic arm or rover components, EVA suit items, unforeseen tools, conformal repair patches, and habitat fittings among others. Except for start-up and shut-down, fabrication will be automatic without crew intervention under nominal scenarios. Off-nominal scenarios may require crew and/or Earth control intervention. System will have the ability to fabricate using both provisioned feedstock materials and feedstock refined from in situ regolith.

  13. Thermal Skin fabrication technology

    NASA Technical Reports Server (NTRS)

    Milam, T. B.

    1972-01-01

    Advanced fabrication techniques applicable to Thermal Skin structures were investigated, including: (1) chemical machining; (2) braze bonding; (3) diffusion bonding; and (4) electron beam welding. Materials investigated were nickel and nickel alloys. Sample Thermal Skin panels were manufactured using the advanced fabrication techniques studied and were structurally tested. Results of the program included: (1) development of improved chemical machining processes for nickel and several nickel alloys; (2) identification of design geometry limits; (3) identification of diffusion bonding requirements; (4) development of a unique diffusion bonding tool; (5) identification of electron beam welding limits; and (6) identification of structural properties of Thermal Skin material.

  14. Fiber heart valve prosthesis: influence of the fabric construction parameters on the valve fatigue performances.

    PubMed

    Vaesken, Antoine; Heim, Frederic; Chakfe, Nabil

    2014-12-01

    Transcatheter aortic valve replacement (TAVR) has become today a largely considered alternative technique to surgical valve replacement in patients who are not operable or patients with high risk for open chest surgery. However, the biological valve tissue used in the devices implanted clinically appears to be fragile material when folded for low diameter catheter insertion purpose and released in calcified environment with irregular geometry. Textile polyester material is characterized by outstanding folding and strength properties combined with proven biocompatibility. It could thereof be considered to replace biological valve leaflets in the TAVR procedure. The textile construction parameters must however be tuned to obtain a material compatible with the valve requested durability. In that context, one issue to be addressed is the friction effect that occurs between filaments and between yarns within a fabric under flexure loading. This phenomenon could be critical for the resistance of the material on the long term. The purpose of the present work is to assess the fatigue performances of textile valve prototypes made from different fabric constructions (monofilament, multifilament, calendered mutifilament) under accelerated cyclic loading. The goal is to identify, which construction is the best suited to long term fatigue stress. Results show that calendered multifilament and monofilament fabric constructions undergo strong ruptures already from 40 Mio cycles, while non calendered multifilament appears more durable. The rupture patterns observed point out that durability is directly related to the flexure stiffness level of the fibrous elements in the construction. PMID:25201184

  15. Accumulation of gas-phase methamphetamine on clothing, toy fabrics, and skin oil.

    PubMed

    Morrison, G; Shakila, N V; Parker, K

    2015-08-01

    To better understand methamphetamine exposure and risk for occupants of former residential clandestine methamphetamine laboratories, we measured the dynamic accumulation of methamphetamine in skin oil, cotton and polyester (PE) clothing, upholstery, and toy fabric (substrates) exposed to 15-30 ppb (91-183 ?g/m(3) ) neutral methamphetamine in air for up to 60 days. The average equilibrium partition coefficients at 30% RH, in units of ?g of methamphetamine per gram of substrate per ppb, are 3.0 ± 0.2 for a PE baby blanket, 5.6 ± 3.5 for a PE fabric toy, 3.7 ± 0.2 for a PE shirt, 18.3 ± 8.0 for a PE/cotton upholstery fabric, and 1200 ± 570 in skin oil. The partition coefficients at 60% RH are 4.5 ± 0.4, 5.2 ± 2.1, 4.5 ± 0.6, 36.1 ± 3.6, and 1600 ± 1100 ?g/(g ppb), respectively. There was no difference in the partition coefficient for a clean and skin-oil-soiled cotton shirt [15.3 ± 2.1 ?g/(g ppb) @ 42 days]. Partition coefficients for skin oil may be sensitive to composition. 'Mouthing' of cloth is predicted to be the dominant exposure pathway [60 ?g/(kg body weight*ppb)] for a toddler in former meth lab, and indoor air concentrations would have to be very low (0.001 ppb) to meet the recommended reference dose for children. PMID:25244432

  16. Cost-efficient fabrication techniques for microchips and interconnects enabled by polycaprolactone

    NASA Astrophysics Data System (ADS)

    Koesdjojo, Myra T.; Nammoonnoy, Jintana; Wu, Yuanyuan; Frederick, Ryan T.; Remcho, Vincent T.

    2012-11-01

    In this paper we present a novel fabrication technique that utilizes polycaprolactone (PCL) as a bonding medium due to its low melting temperature property. PCL is biodegradable polyester with a melting point of 60 °C, and a glass transition temperature of -60 °C [1-10]. It is used as a rapid bonding medium in the fabrication process that readily produces complete microfluidic chips. The microchannels are produced via laser ablation micromachining and thermal embossing, followed by bonding with PCL. The PCL is uniformly coated on a piece of polymer sheet to produce a thin film on its surface. A complete microfluidic channel is formed by enclosing the open channel with the PCL-coated polymer piece. This fabrication technique lends itself readily to various polymers, such as (poly)methylmethacrylate (PMMA), polycarbonate (PC), polyetherimide (PEI) and poly(ethylene terephthalate) (PETE), facilitating device production for a variety of application, even permitting hybrid polymer chips. The bonding was performed rapidly at 60 °C. This approach provides a more direct method to generate hard polymer microfluidic chips than classical techniques and is therefore highly amendable to rapid prototyping. This work also explores the use of PCL as an alternative approach to making simple, cost-effective universal adhesive for bonding interconnects. Bonding is performed at 60 °C, by placing the adhesive layer in between an interconnect port and a microchip. This method allows for connections to be made easily and quickly.

  17. Structure development of polyesters and their blends in film formation processes

    Microsoft Academic Search

    Kwangjin Song

    1998-01-01

    A fundamental study of structure development in cast, single and double bubble, and biaxial film stretching processes of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) and PBT\\/PET blends was carried out. The deformation mechanisms and physical properties of films were described in terms of various structural parameters. We established a new process technique to fabricate double bubble biaxially

  18. Cure shrinkage characterization and modeling of a polyester resin containing low profile additives

    Microsoft Academic Search

    Mohsan Haider; Pascal Hubert; Larry Lessard

    2007-01-01

    Resin Transfer Moulding (RTM) has great potential as an efficient and economical process for fabricating large and complicated composite structural components. The low capital investment cost required and process versatility in component integration and assembly make RTM very attractive for high volume automotive applications. One of the challenges facing the automotive field is the resulting surface finish of manufactured components.

  19. The physical properties of the surface of apparel made from flax and polyester fibres

    Microsoft Academic Search

    Ma?gorzata Zimniewska; Marina Michalak; Izabella Kruci?ska; Bogus?aw Wi?cek

    2003-01-01

    In this paper, the clothes made of synthetic and natural fibres were tested. The characteristics of selected physical parameters such as temperature, electrical resistance, thermal resistance of fabrics used for tested clothes have been presented. The electrostatical charge and temperature distribution of clothes were investigated on human body. The temperature distribution and the coefficient of heat transmission were measured by

  20. Tests of Flammability of Cotton Fabrics and Expected Skin Burns in Microgravity

    NASA Technical Reports Server (NTRS)

    Cavanagh, Jane M.; Torvi, David A.; Gabriel, Kamiel S.; Ruff, Gary A.

    2004-01-01

    During a shuttle launch and other portions of space flight, astronauts wear specialized flame resistant clothing. However during most of their missions on board the Space Shuttle or International Space Station, astronauts wear ordinary clothing, such as cotton shirts and pants. As the behaviour of flames is considerably different in microgravity than under earth's gravity, fabrics are expected to burn in a different fashion in microgravity than when tested on earth. There is interest in determining how this change in burning behaviour may affect times to second and third degree burn of human skin, and how the results of standard fabric flammability tests conducted under earth's gravity correlate with the expected fire behaviour of textiles in microgravity. A new experimental apparatus was developed to fit into the Spacecraft Fire Safety Facility (SFSF), which is used on NASA's KC-135 low gravity aircraft. The new apparatus was designed to be similar to the apparatus used in standard vertical flammability tests of fabrics. However, rather than using a laboratory burner, the apparatus uses a hot wire system to ignite 200 mm high by 80 mm wide fabric specimens. Fabric temperatures are measured using thermocouples and/or an infrared imaging system, while flame spread rates are measured using real time observations or video. Heat flux gauges are placed between 7 and 13 mm away from the fabric specimen, so that heat fluxes from the burning fabric to the skin can be estimated, along with predicted times required to produce skin burns. In November of 2003, this new apparatus was used on the KC-135 aircraft to test cotton and cotton/polyester blend fabric specimens in microgravity. These materials were also been tested using the same apparatus in 1-g, and using a standard vertical flammability test that utilizes a flame. In this presentation, the design of the test apparatus will be briefly described. Examples of results from the KC-135 tests will be provided, including heat fluxes and skin burn predictions. These results will be compared with results from 1-g tests using the same apparatus and a standard fabric flammability test apparatus. Recommendations for future microgravity fabric flammability tests will also be discussed.

  1. Comparative studies on the non-isothermal DSC curing kinetics of an unsaturated polyester resin using free radicals and empirical models

    Microsoft Academic Search

    J. L. Martín; A. Cadenato; J. M. Salla

    1997-01-01

    In this paper, we study the kinetics of the curing of an unsaturated polyester resin initiated with MEKP by means of DSC. DSC runs were performed at different heating rates. The experimental curves were fitted using two kinetic models: one involving the concept of free-radical polymerization, and the other an empirical model that does not take into account the different

  2. Low temperature measurement of thermal and mechanical properties of phenolic laminate, the pultruded polyester fiberglass and A and B epoxy putty. [Micarta

    Microsoft Academic Search

    S. T. Wang; S. H. Kim; N. S. Kim; R. S. Cheng; J. Hoffman; J. Gonczy

    1979-01-01

    Low temperature measurements were made and are reported of thermal and mechanical properties of phenolic laminate, pultruded polyester fiberglass, and A and B epoxy putty. To determine the modulus, compressive and tensile stress and strain, an Instron machine, a Tinus-Olsen testing machine, a Wheatstone bridge and strain gages were used. (FS)

  3. Effect of wettability and ageing conditions on the physical and mechanical properties of uniaxially oriented jute-roving-reinforced polyester composites

    Microsoft Academic Search

    A. C de Albuquerque; Kuruvilla Joseph; Laura Hecker de Carvalho; Jose Roberto Morais d'Almeida

    2000-01-01

    In order to obtain reliable composite materials in structural applications and to utilise fully the potential of reinforcing fibres, both perfect impregnation and strong interfacial bond formation have to be guaranteed. In the present study the tensile, flexural, and impact behaviour of jute roving reinforced polyester composites were investigated as a function of fibre loading and fibre surface wettability. Two

  4. Scheduling semiconductor wafer fabrication

    Microsoft Academic Search

    LAWRENCE M. WEIN

    1988-01-01

    The impact that scheduling can have on the performance of semi-conductor wafer fabrication facilities is assessed. The performance measure considered is the mean throughput time (sometimes called cycle time, turnaround time or manufacturing interval) for a lot of wafers. A variety of input control and sequencing rules are evaluated using a simulation model of a representative, but fictitious, semiconductor wafer

  5. Animated Texels Fabrice Neyret

    E-print Network

    Paris-Sud XI, Université de

    Animated Texels Fabrice Neyret INRIA, Syntim Project B.P. 105, 78153 Le Chesnay Cedex, France of animating complex repetitive geometries, like the effects produced by the wind in a wheat field, or fur], hypertextures [7], volumetric textures [4, 5]. Animating these objects is also a very important point

  6. Prototype space fabrication platform

    Microsoft Academic Search

    James A. Bessel; James M. Ceney; David M. Crean; Edward A. Ingham; David J. Pabst

    1993-01-01

    Current plans for constructing large structures in space entail fabricating the primary components, such as truss segments, on the ground and assembling them in space. This process requires an exorbitant number of support missions, and methods to minimize the number must be considered. Whenever the space shuttle is launched, its external tank is jettisoned and destroyed prior to reaching orbit.

  7. Fabrication of boron articles

    Microsoft Academic Search

    Benton

    1976-01-01

    This invention is directed to the fabrication of boron articles by a powder metallurgical method wherein the articles are of a density close to the theoretical density of boron and are essentially crackfree. The method comprises the steps of admixing 1 to 10 weight percent carbon powder with amorphous boron powder, cold pressing the mixture and then hot pressing the

  8. Smart Fabric, or \\

    Microsoft Academic Search

    Rehmi Post; Maggie Orth

    1997-01-01

    Abstract Wearable computers can now merge seamlessly into ordinary clothing. Using various conductive textiles, data and power distribution as well,as sensing circuitry can be incorporated,directly,into wash-and-wear clothing. This paper describes some of the techniques used,to build circuits from commercially available fabrics, yarns, fasteners, and components.

  9. Optical Properties Of Ceramic Fabrics

    NASA Technical Reports Server (NTRS)

    Covington, M. A.; Sawko, P. M.

    1990-01-01

    Report discusses optical properties of ceramic fabrics woven from silica, aluminoborosilicate, and silicon carbide yarns. Directional hemispheric reflectance and transmittance data given for several different weave patterns, yarn constructions, and fabric weights.

  10. Space Fabrication Demonstration System

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The completion of assembly of the beam builder and its first automatic production of truss is discussed. A four bay, hand assembled, roll formed members truss was built and tested to ultimate load. Detail design of the fabrication facility (beam builder) was completed and designs for subsystem debugging are discussed. Many one bay truss specimens were produced to demonstrate subsystem operation and to detect problem areas.

  11. In vitro studies of degradation and bioactivity of aliphatic polyester composites

    NASA Astrophysics Data System (ADS)

    Chouzouri, Georgia

    In spite of numerous publications on the potential use of combinations of aliphatic polyester composites containing bioactive fillers for bone regeneration, little information exists on the combined in vitro mechanisms involving simultaneously diffusion for polymer degradation and bioactivity through nucleation and growth of apatite in simulated body fluid (SBF) solution. The objective of this study is to contribute to the understanding of the fundamentals in designing non-porous, solid materials for bone regeneration, from experimental data along with their engineering interpretation. Bioactivity, in terms of apatite growth, was assessed through several experimental methods such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray-diffraction (XRD) and changes in ion concentration. In the case of the six neat fillers evaluated, the filler shape, form and chemical structure showed significant differences in bioactivity response. Bioglass and calcium silicate fillers showed faster nucleation and growth rates in the screening experiments. Composites at 30% by weight filler were prepared by solution and/or melt mixing. Polycaprolactone (PCL) composites containing five different fillers were evaluated. Solution processed PCL/calcium silicate (CS) samples showed faster bioactivity, as determined by apatite growth, compared to melt mixed samples. The onset time for bioactivity was different for all PCL composites. The limited bioactivity in the PCL composites over longer periods of time could be attributed to the PCL hydrophobicity leading to a slow polymer degradation rate, and also to the lack of SBF replenishment. For both polylactic acid (PLA) composites containing CS and bioglass, significant growth was observed after one week and in the case of CS was still evident after four weeks immersion. However, at prolonged time periods no further bioactivity was observed, although ion release results indicated a faster release rate that would eventually lead to a faster polymer degradation and possibly continuing bioactivity. The presence of silicate fillers enhanced the hydrolytic degradation rate of both PCL and PLA as shown from kinetic data calculations based on molecular weight measurements. Unfilled PLA samples showed significant embrittlement after two weeks immersion, whereas for the CS filled system more significant changes could be observed in the compressive strength and modulus after the same time period. Experimental data were also fitted into an equation proposed to calculate erosion number; in the case of unfilled PLA predictions were found to agree with literature results suggesting bulk erosion. By assuming impermeable, randomly dispersed glass flakes, water transport in a composite system, prior to significant polymer degradation could be modeled. However, modeling of transport in the case of the composite consisting of a degrading polymer and a reactive decaying filler was challenging, particularly in the case of directional bioactive reinforcements, due to the occurrence of simultaneous time dependent diffusion phenomena that altered the integrity of the sample.

  12. Effect of fiber surface modification on the mechanical and water absorption characteristics of sisal\\/polyester composites fabricated by resin transfer molding

    Microsoft Academic Search

    P. A. Sreekumar; Selvin P. Thomas; Jean marc Saiter; Kuruvilla Joseph; G. Unnikrishnan; Sabu Thomas

    2009-01-01

    Sisal fibers were subjected to various chemical and physical modifications such as mercerization, heating at 100°C, permanganate treatment, benzoylation and silanization to improve the interfacial bonding with matrix. Composites were prepared by these fibers as reinforcement, using resin transfer molding (RTM). The mechanical properties such as tensile, flexural and impact strength were examined. Mercerized fiber-reinforced composites showed 36% of increase

  13. The influence of SF6 and SF6/N2 gas pressure to the breakdown performance of polyester film

    SciTech Connect

    Zhang Peihong; Gong Guoli; Dong Guangyu [Harbin Univ. of Science and Technology (China). Dept. of Electrical Material; Dong Zhenhua [Shenyang Research Inst. of Transformer (China)

    1996-12-31

    SF6 has been widely used as the gas insulating medium in gas insulated transformer, and polyester film used as the turn insulation and other insulating materials. In this paper, the insulation strength of turn insulation of SF6/N2-film is tested when the SF6 is replaced by SF6/N2 mixed gas, and also compared with that of SF6-film. The results show that the power frequency breakdown voltage and breakdown stress of SF6/N2-film is lower than that of SF6-film in the same pressure and the same film thickness, the mean value of the former is about 91% of the latter. In order to reach the same level of turn insulation strength in the operation range, the gas pressure must be increased by 0.05 Mpa.

  14. Study on Stretching Methods of Biaxially Stretched Co-polyester Film with Has Uniaxially Heat Shrinkage Properties

    NASA Astrophysics Data System (ADS)

    Haruta, Masayuki; Mukouyama, Yukinobu; Tabota, Norimi; Ito, Katsuya; Nonomura, Chisato

    Heat shrinkable film made of stretched film is widely used for decorative labels by attaching on PET bottles with heat shrinkage by steam or dry heating. Trouble cancellation in the installation process of the PET bottle is necessary. The purpose of this study is development of uniaxially heat shrinkable co-polyester film that has strength both in the machine direction (MD) and transverse direction (TD). The film production was performed using sequential biaxial stretched process that combined roll stretching with TD stretching. Cast film was processed in the order of TD stretching-Anneal 1-MD stretching-Anneal 2. As a result, the heat shrinkable film that shrunk only in MD got high tensile strength both in MD and TD. The anneal 1 temperature over Tg (Glass transition temperature) of material resin was needed to obtain the heat shrinkable film shrunk in MD after TD stretching.

  15. Chirality Effects on the Morphology and Phase Behavior of a Synthetic Main-chain Liquid Crystal Polyester

    NASA Astrophysics Data System (ADS)

    Weng, Xin; Zhang, John Z.; Bai, Feng; Li, Christopher Y.; Jin, Shi; Harris, Frank W.; Cheng, Stephen Z. D.

    2002-03-01

    A main-chain liquid crystal chiral polyester is synthesized via an A-B type condensation polymerization from (R)-(-)-4'-w-[2-(p-hydroxy-o-nitrophenyloxy)-1-propyloxy]-1-undecyloxy-4- biphenyl carboxylic acid. The resulting polymer exhibits multiple chiral liquid crystal phases at different temperatures, including chiral smectic A and C phases, as indicated by DSC, PLM and WAXD. Flat and helical single lamellar crystals have been obtained over a certain temperature range by melt crystallization and solvent evaporation techniques. All helical crystals show a right-handed twist with pitch lengths on the micrometer scale as observed by TEM and AFM. The crystal structures of the flat and helical crystals are determined to be orthorhombic by electron diffraction and WAXD fiber pattern experiments.

  16. Water-cooled non-thermal gliding arc for adhesion improvement of glass-fibre-reinforced polyester

    NASA Astrophysics Data System (ADS)

    Kusano, Yukihiro; Sørensen, Bent F.; Andersen, Tom L.; Toftegaard, Helmuth L.; Leipold, Frank; Salewski, Mirko; Sun, Zhiwei; Zhu, Jiajian; Li, Zhongshan; Alden, Marcus

    2013-04-01

    A non-equilibrium quenched plasma is prepared using a gliding-arc discharge generated between diverging electrodes and extended by a gas flow. It can be operated at atmospheric pressure and applied to plasma surface treatment to improve adhesion properties of material surfaces. In this work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding-arc discharge with air flow to improve adhesion with a vinylester adhesive. The electrodes were water-cooled so as to operate the gliding arc continually. The treatment improved wettability and increased the density of oxygen-containing polar functional groups on the surfaces. Double cantilever beam specimens were prepared for fracture mechanic characterization of the laminate adhesive interface. It was found that gliding-arc treatment significantly increases the fracture resistance in comparison with a standard peel-ply treatment.

  17. Synthesis and characterization of rodlike liquid crystalline polyester/multi-walled carbon nanotubes and study of their thermal stability

    NASA Astrophysics Data System (ADS)

    Hu, Wu-Quan; Cui, Zhen-Kai; Jin, Jun; Dong, Zheng-Ping; Li, Shu-Wen; Wang, Peng; Ding, Wen; Li, Rong

    2011-10-01

    Rodlike thermotropic liquid crystalline polyester (TLCP) was synthesized from 4,4'-oxydibenzoyl chloride and resorcinol containing modified multi-walled carbon nanotubes (MWCNTs) by in situ high-temperature solution polymerization. The liquid crystalline properties and thermal stability of the resulted TLCP nanocomposites were characterized by XRD, DSC, TGA, SEM, POM, and optical analysis. The addition of small amount of MWCNTs into TLCP matrix could significantly improve the thermal stability. The mesophase temperature range of nanocomposites were widened and shifted to higher temperatures. This nanocomposite melting phase transition ( Tm) value increases maximally to 38.4 °C compared with pure copolymer. Using the Horowits-Metzger kinetic method, the PE/M-0.5 gave the best performance in terms of the thermal stability. This result can be explained that the incorporation of MWCNTs into TLCP caused an interaction between TLCP and MWCNTs through ?-?* conjugation.

  18. Three-dimensional nonwoven scaffolds from a novel biodegradable poly(ester amide) for tissue engineering applications.

    PubMed

    Hemmrich, Karsten; Salber, Jochen; Meersch, Melanie; Wiesemann, Ute; Gries, Thomas; Pallua, Norbert; Klee, Doris

    2008-01-01

    Biodegradable polyesters are established biomaterials in medicine due to their chemical characteristics and options for material processing. A main problem, however, is the release of acid degradation products during biodegradation with severe local pH-drops and inflammatory reactions. Polyesteramides, in contrast, show a less prominent pH-drop during degradation. In this study, we developed a simple, reproducible synthesis of the poly(ester amide) (PEA) type C starting from epsilon-caprolactame, 1,4-butanediol, and adipic acid in a one-batch two-step reaction and conducted the manufacturing of PEA-derived 3D textile scaffolds applicable for tissue engineering purposes. The thermal and mechanical properties of PEA-type C were analysed and the structural conformity of different batches was confirmed by NMR spectroscopy and size exclusion chromatography. The polymer was formed into nonwovens by textile manufacturing. Cytotoxicity tests and X-ray photoelectron spectroscopy (XPS) were used to analyze the effect of scaffold extraction before cell seeding. The manufactured carriers were seeded with human preadipocytes and examined for cellular proliferation and differentiation. The production of PEA type C successfully occurred via simultaneous ring-opening polymerization of epsilon-caprolactame and polycondensation with 1,4-butanediol and adipic acid at 250 degrees C under high-vacuum. Soxhlet extraction allowed optimal cleaning of nonwoven scaffolds. Extracted PEA-derived matrices were capable of allowing good adherence, proliferation, and differentiation of preadipocytes. These results are encouraging and guidance towards an optimally prepared nonwoven carrier applicable for clinical use. PMID:17597366

  19. Friction and wear behaviour of Kevlar fabrics

    Microsoft Academic Search

    M. A. Martínez; C. Navarro; R. Cortés; J. Rodríguez; N. Sanchez-Galvez

    1993-01-01

    Experimental results of a number of tribological tests carried out on aramid woven fabrics are presented in this paper. Kevlar Ht, Kevlar 29 and Kevlar 49 aramid plain fabrics were employed in this work. The friction and wear phenomena of the fabrics were investigated, considering both fabric-fabric and metal-fabric interaction. From the experimental data, the evolution of parameters such as

  20. Fabrication of polypyrrole nanowires

    NASA Astrophysics Data System (ADS)

    Berdichevsky, Yevgeny; Lo, Yu-Hwa

    2005-05-01

    An artificial muscle composed of electroactive nanowires or nanofibers would compare favorably to its biological counterpart in terms of generated force and speed, while devices based on discrete nanoactuators could perform functions similar to those of motor proteins in biological cells. A template synthesis method for producing polypyrrole nanowires is examined. Conductivity and electrochemical properties of resulting nanowires are evaluated, showing promise for future use as nanoactuators. Template synthesis is then extended to allow fabrication of polypyrrole nanowires directly on a planar substrate such as semiconductor wafer, enabling potential integration with semiconductor or microfluidic devices.

  1. Electrochemical fabrication of capacitors

    DOEpatents

    Mansour, Azzam N. (Fairfax Sta., VA); Melendres, Carlos A. (Lemont, IL)

    1999-01-01

    A film of nickel oxide is anodically deposited on a graphite sheet held in osition on an electrochemical cell during application of a positive electrode voltage to the graphite sheet while exposed to an electrolytic nickel oxide solution within a volumetrically variable chamber of the cell. An angularly orientated x-ray beam is admitted into the cell for transmission through the deposited nickel oxide film in order to obtain structural information while the film is subject to electrochemical and in-situ x-ray spectroscopy from which optimum film thickness, may be determined by comparative analysis for capacitor fabrication purposes.

  2. Fabrication of compliant hybrid grafts supported with elastomeric meshes.

    PubMed

    Kobashi, T; Matsuda, T

    1999-01-01

    We devised tubular hybrid medial tissues with mechanical properties similar to those of native arteries, which were composed of bovine smooth muscle cells (SMCs) and type I collagen with minimal reinforcement with knitted fabric meshes made of synthetic elastomers. Three hybrid medial tissue models that incorporated segmented polyester (mesh A) or polyurethane-nylon (mesh B) meshes were designed: the inner, sandwich, and wrapping models. Hybrid medial tissues were prepared by pouring a cold mixed solution of SMCs and collagen into a tubular glass mold consisting of an inner mandrel and an outer sheath and subsequent thermal gelation, followed by further culture for 7 days. For the inner model, the mandrel was wrapped with a mesh. For the sandwich model, a cylindrically shaped mesh was incorporated into a space between the mandrel and the sheath. The wrapping model was prepared by wrapping a 7-day-incubated nonmesh gel with a mesh. The inner diameter was 3 mm, irrespective of the model, and the length was 2.5-4.0 cm, depending on the model. The intraluminal pressure-external diameter relationship showed that nonmesh and inner models had a very low burst strength below 50 mmHg, while the sandwich model ruptured at around 110-120 mmHg; no rupturing below 240 mmHg was observed for the wrapping model, regardless of the type of mesh used. Compliance values of wrapping and sandwich models were close to those of native arteries. Pressure-dependent distensibility characteristics similar to native arteries were observed for a mesh A wrapping model, whereas a mesh B wrapping model expanded almost linearly as intraluminal pressure increased, which appeared to be due to elasticity of the incorporated mesh. Thus, design criteria for hybrid vascular grafts with appropriate biomechanical matching with host arteries were established. Such hybrid grafts may be mechanically adapted in an arterial system. PMID:10580342

  3. Fabricating a hybrid imaging device

    NASA Technical Reports Server (NTRS)

    Wadsworth, Mark (Inventor); Atlas, Gene (Inventor)

    2003-01-01

    A hybrid detector or imager includes two substrates fabricated under incompatible processes. An array of detectors, such as charged-coupled devices, are formed on the first substrate using a CCD fabrication process, such as a buried channel or peristaltic process. One or more charge-converting amplifiers are formed on a second substrate using a CMOS fabrication process. The two substrates are then bonded together to form a hybrid detector.

  4. AFIP-2 Fabrication Summary Report

    SciTech Connect

    Glenn Moore

    2010-02-01

    The Advanced Test Reactor (ATR) Full-size Plate In Center Flux Trap Position (AFIP)-2 experiment was designed to evaluate the performance of monolithic fuels at a scale prototypic of research reactor fuel plates. Two qualified fueled plates were fabricated for the AFIP 2 experiment to be irradiated in the Idaho National Laboratory ATR. This report provides details of the fuel fabrication efforts, including material selection, fabrication processes, and fuel plate qualification.

  5. AFIP-4 Fabrication Summary Report

    SciTech Connect

    Glenn A. Moore

    2010-02-01

    The AFIP-4 (ATR Full –size-plate In center flux trap Position) experiment was designed to evaluate the performance of monolithic fuels at a scale prototypic of research reactor fuel plates. Twelve qualified fueled plates were fabricated for the AFIP-4 experiment; to be irradiated in the INL Advanced Test Reactor (ATR). This report provides details of the fuel fabrication efforts; including material selection, fabrication processes, and fuel plate qualification.

  6. Factorial optimisation of the effects of extrusion temperature profile and polymer grade on as?spun aliphatic–aromatic co?polyester fibres III: mechanical properties

    Microsoft Academic Search

    Basel Younes; Alex Fotheringham

    2011-01-01

    The effect of extrusion temperature profile in the melt?spinning process of as?spun linear aliphatic–aromatic co?polyester (AAC) fibres upon their mechanical properties and process productivity was modelled by using factorial experimental designs. After the viscoelastic and morphology characteristics of the polymer were considered using Differential Scanning Calorimetry and Melt Flow Index (MFI), the rheological data were used to determine the enhanced

  7. Factorial optimisation of the effects of extrusion temperature profile and polymer grade on as-spun aliphatic–aromatic co-polyester fibres III: mechanical properties

    Microsoft Academic Search

    Basel Younes; Alex Fotheringham

    2012-01-01

    The effect of extrusion temperature profile in the melt?spinning process of as?spun linear aliphatic–aromatic co?polyester (AAC) fibres upon their mechanical properties and process productivity was modelled by using factorial experimental designs. After the viscoelastic and morphology characteristics of the polymer were considered using Differential Scanning Calorimetry and Melt Flow Index (MFI), the rheological data were used to determine the enhanced

  8. The effect of alkalization and fibre alignment on the mechanical and thermal properties of kenaf and hemp bast fibre composites: Part 1 – polyester resin matrix

    Microsoft Academic Search

    Sharifah H. Aziz; Martin P. Ansell

    2004-01-01

    Long and random hemp and kenaf fibres were used in the as-received condition and alkalized with a 0.06 M NaOH solution. They were combined with polyester resin and hot-pressed to form natural fibre composites. The mechanical properties of the composites were measured to observe the effect of fibre alignment and alkalization. A general trend was observed whereby alkalized and long

  9. Construction of chiral polyesters from polycondensation of multifunctional monomer containing both flexible amino acid and rigid pendant groups with aromatic diols

    Microsoft Academic Search

    Shadpour Mallakpour; Marziyeh Khani

    2010-01-01

    A number of chiral wholly aromatic polyesters (PEs) with phthalimido and flexible chiral unit in the backbone were prepared\\u000a from a chiral synthesized diacid monomer, 5-(3-methyl-2-phthalimidylpentanoylamino)isophthalic acid (1), and various aromatic diols via the polyesterification reaction. The tosyl chloride\\/pyridine\\/N,N-dimethylformamide (DMF) system was used as a condensing agent. All of the these polymers having bulky phthalimido and amino\\u000a acid functionalities in

  10. New Skin Test for Detection of Bovine Tuberculosis on the Basis of Antigen-Displaying Polyester Inclusions Produced by Recombinant Escherichia coli

    PubMed Central

    Chen, Shuxiong; Parlane, Natalie A.; Lee, Jason; Wedlock, D. Neil; Buddle, Bryce M.

    2014-01-01

    The tuberculin skin test for diagnosing tuberculosis (TB) in cattle lacks specificity if animals are sensitized to environmental mycobacteria, as some antigens in purified protein derivative (PPD) prepared from Mycobacterium bovis are present in nonpathogenic mycobacteria. Three immunodominant TB antigens, ESAT6, CFP10, and Rv3615c, are present in members of the pathogenic Mycobacterium tuberculosis complex but absent from the majority of environmental mycobacteria. These TB antigens have the potential to enhance skin test specificity. To increase their immunogenicity, these antigens were displayed on polyester beads by translationally fusing them to a polyhydroxyalkanoate (PHA) synthase which mediated formation of antigen-displaying inclusions in recombinant Escherichia coli. The most common form of these inclusions is poly(3-hydroxybutyric acid) (PHB). The respective fusion proteins displayed on these PHB inclusions (beads) were identified using tryptic peptide fingerprinting analysis in combination with matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). The surface exposure and accessibility of antigens were assessed by enzyme-linked immunosorbent assay (ELISA). Polyester beads displaying all three TB antigens showed greater reactivity with TB antigen-specific antibody than did beads displaying only one TB antigen. This was neither due to cross-reactivity of antibodies with the other two antigens nor due to differences in protein expression levels between beads displaying single or three TB antigens. The triple-antigen-displaying polyester beads were used for skin testing of cattle and detected all cattle experimentally infected with M. bovis with no false-positive reactions observed in those sensitized to environmental mycobacteria. The results suggested applicability of TB antigen-displaying polyester inclusions as diagnostic reagents for distinguishing TB-infected from noninfected animals. PMID:24532066

  11. Electrostatic fluidized bed (EFB) coating of heat sensitive and electrical insulating substrates with low-curing thermoset epoxy-polyester (EP) powders

    Microsoft Academic Search

    M. Barletta

    2006-01-01

    In this study, the electrostatic fluidized bed (EFB) coating process of heat sensitive and electrical insulating substrates with low-curing thermoset epoxy-polyester (EP) powders is researched. A relatively novel prepaint treatment, based on a peening process of plastic substrates with copper powders and performed inside an abrasive fluidized bed (AFB), is developed and analyzed.The influence of EFB coating process parameters, that

  12. Degradation of cross-linked aliphatic polyester composed of poly(?-caprolactone- co- d, l-lactide) depending on the thermal properties

    Microsoft Academic Search

    Takanari Muroya; Kazuya Yamamoto; Takao Aoyagi

    2009-01-01

    In this study, we prepared cross-linked aliphatic polyester derived from branched poly(?-caprolactone (abbreviated as CL)-co-d,l-lactide (abbreviated as LA)) macromonomers with different CL and LA compositions and investigated the effect of thermal properties on their degradation. According to the degradation study, the weight loss became larger with increasing LA composition in poly(CL-co-LA). The introduction of LA units that can degrade easily

  13. Correlation of observations made by DSC and hot-stage optical microscopy of the thermal properties of a monotropic liquid-crystal polyester

    Microsoft Academic Search

    Z. Bashir; N. Khan

    1996-01-01

    The polyester formed by condensation of 4,4?-bis(6-hydroxyhexoxy)biphenyl (BHHBP) and isophthalic acid has been reported to show many interesting and intriguing thermal properties. By optical microscopy, we established that the polymer shows monotropic liquid-crystalline behaviour. Thus, on heating, no mesophases are formed and the crystal melts directly to the isotropic state; on cooling, however, the material transforms from the isotropic melt

  14. Interlocked fabric and laminated fabric Kevlar 49/epoxy composites

    SciTech Connect

    Guess, T.R.; Reedy, E.D. Jr.

    1988-01-01

    The mechanical behavior of a novel interlocked fabric reinforced Kevlar 49/epoxy composite has been measured and compared to those of a laminated Kevlar 49 fabric composite (which served as a reference material). Both composites were 5.0 mm thick, contained the same 50% in-plane fiber volume fraction and were fabricated in a similar manner using the same Dow DER 332 epoxy, Jeffamine T403-hardened resin system. The reference material (Material 1) was reinforced with seven plies of Dupont style 1033 Kevlar 49 fabric. A photomicrograph of a section polished parallel to one of the fiber directions is shown. The interlocked fabric was designed and woven for Sandia National Laboratories by Albany International Research Co., Dedham, MA. The main design criterion was to duplicate a sewn through-the-thickness fabric used in preliminary studies. The interlocked fabric composite (Material 2) contains roughly 4% by volume of through-the-thickness fiber reinforcement for the purpose of improving interlaminar strength. A photomicrograph of a section showing the warp-aligned binder yarns interlocking the six fabric plies together is shown. 2 refs., 8 figs.

  15. Multifunctional graphene woven fabrics

    PubMed Central

    Li, Xiao; Sun, Pengzhan; Fan, Lili; Zhu, Miao; Wang, Kunlin; Zhong, Minlin; Wei, Jinquan; Wu, Dehai; Cheng, Yao; Zhu, Hongwei

    2012-01-01

    Tailoring and assembling graphene into functional macrostructures with well-defined configuration are key for many promising applications. We report on a graphene-based woven fabric (GWF) prepared by interlacing two sets of graphene micron-ribbons where the ribbons pass each other essentially at right angles. By using a woven copper mesh as the template, the GWF grown from chemical vapour deposition retains the network configuration of the copper mesh. Embedded into polymer matrices, it has significant flexibility and strength gains compared with CVD grown graphene films. The GWFs display both good dimensional stability in both the warp and the weft directions and the combination of film transparency and conductivity could be optimized by tuning the ribbon packing density. The GWF creates a platform to integrate a large variety of applications, e.g., composites, strain sensors and solar cells, by taking advantages of the special structure and properties of graphene. PMID:22563524

  16. Protein fabrication automation

    PubMed Central

    Cox, J. Colin; Lape, Janel; Sayed, Mahmood A.; Hellinga, Homme W.

    2007-01-01

    Facile “writing” of DNA fragments that encode entire gene sequences potentially has widespread applications in biological analysis and engineering. Rapid writing of open reading frames (ORFs) for expressed proteins could transform protein engineering and production for protein design, synthetic biology, and structural analysis. Here we present a process, protein fabrication automation (PFA), which facilitates the rapid de novo construction of any desired ORF from oligonucleotides with low effort, high speed, and little human interaction. PFA comprises software for sequence design, data management, and the generation of instruction sets for liquid-handling robotics, a liquid-handling robot, a robust PCR scheme for gene assembly from synthetic oligonucleotides, and a genetic selection system to enrich correctly assembled full-length synthetic ORFs. The process is robust and scalable. PMID:17242375

  17. A comparison of the use of vacuum metal deposition versus cyanoacrylate fuming for visualisation of fingermarks and grab impressions on fabrics.

    PubMed

    Fraser, Joanna; Deacon, Paul; Bleay, Stephen; Bremner, David H

    2014-03-01

    Both vacuum metal deposition (VMD) and cyanoacrylate fuming (CAF) are techniques used to visualise latent fingermarks on smooth non-porous surfaces such as plastic and glass. VMD was initially investigated in the 1970s as to its effectiveness for visualising prints on fabrics, but was abandoned when radioactive sulphur dioxide was found to be more effective. However, interest in VMD was resurrected in the 1990s when CAF was also used routinely. We now report on studies to determine whether VMD or CAF is the more effective technique for the detection of marks on fabrics. Four different fabrics, nylon, polyester, polycotton and cotton, were utilised during this study, along with 15 donors who ranged in their age and ability to leave fingermarks, from good to medium to poor, thus reflecting the general population. Once samples were collected they were kept for a determined time (1, 2, 3, 4, 5, 6, 7, 14, 21 or 28 days) and then treated using either the gold and zinc metal VMD process or standard cyanoacrylate fuming. The smoother fabrics, such as nylon, consistently produced greater ridge detail whereas duller fabrics, like cotton tended only to show empty prints and impressions of where the fabric had been touched, rather than any ridge details. The majority of fabrics did however allow the development of touch marks that could be targeted for DNA taping which potentially could lead to a DNA profile. Of the two techniques VMD was around 5 times more effective than CAF, producing a greater amount of ridge detail, palmar flexion creases and target areas on more samples and fabrics. PMID:24630323

  18. Polyester production by halophilic and halotolerant bacterial strains obtained from mangrove soil samples located in Northern Vietnam.

    PubMed

    Van-Thuoc, Doan; Huu-Phong, Tran; Thi-Binh, Nguyen; Thi-Tho, Nguyen; Minh-Lam, Duong; Quillaguamán, Jorge

    2012-12-01

    This research article reports halophilic and halotolerant bacteria isolated from mangrove forests located in Northern Vietnam. Several of these bacteria were able to synthesize polyhydroxyalkanoates (PHAs). PHAs are polyesters stored by microorganisms under the presence of considerable amounts of a carbon source and deficiency of other essential nutrient such as nitrogen or phosphorous. Mangrove forests in Northern Vietnam are saline coastal habitats that have not been microbiologically studied. Mangrove ecosystems are, in general, rich in organic matter, but deficient in nutrients such as nitrogen and phosphorus. We have found about 100 microorganisms that have adapted to mangrove forests by accumulating PHAs. The production of polyesters might therefore be an integral part of the carbon cycle in mangrove forests. Three of the strains (ND153, ND97, and QN194) isolated from the Vietnamese forests were identified as Bacillus species, while other five strains (QN187, ND199, ND218, ND240, and QN271) were phylogenetically close related to the ?-proteobacterium Yangia pacifica. These strains were found to accumulate PHAs in noticeable amounts. Polymer inclusions and chemical structure were studied by transmission electron microscopy and proton nuclear magnetic resonance (NMR) spectroscopy analyses, respectively. Strains ND153, ND97, QN194, QN187, ND240, and QN271 synthesized poly(3-hydroxybutyrate) (PHB) from glucose, whereas strains ND199 and ND218 synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from this carbohydrate. With the exception of strain QN194, the strains accumulated PHBV when a combination of glucose and propionate was included in the culture medium. The polymer yields and cell growth reached by one Bacillus isolate, strain ND153, and one Gram-negative bacterium, strain QN271, were high and worth to be researched further. For experiments performed in shake flasks, strain ND153 reached a maximum PHBV yield of 71 wt% and a cell dry weight (CDW) of 3.6 g/L while strain QN271 attained a maximum PHB yield of 48 wt% and a CDW of 5.1 g/L. Both strain ND153 and strain QN271 may only represent a case in point that exemplifies of the potential that mangrove forests possess for the discovery of novel halophilic and halotolerant microorganisms able to synthesize different types of biopolyesters. PMID:23233461

  19. Polyester production by halophilic and halotolerant bacterial strains obtained from mangrove soil samples located in Northern Vietnam

    PubMed Central

    Van-Thuoc, Doan; Huu-Phong, Tran; Thi-Binh, Nguyen; Thi-Tho, Nguyen; Minh-Lam, Duong; Quillaguamán, Jorge

    2012-01-01

    This research article reports halophilic and halotolerant bacteria isolated from mangrove forests located in Northern Vietnam. Several of these bacteria were able to synthesize polyhydroxyalkanoates (PHAs). PHAs are polyesters stored by microorganisms under the presence of considerable amounts of a carbon source and deficiency of other essential nutrient such as nitrogen or phosphorous. Mangrove forests in Northern Vietnam are saline coastal habitats that have not been microbiologically studied. Mangrove ecosystems are, in general, rich in organic matter, but deficient in nutrients such as nitrogen and phosphorus. We have found about 100 microorganisms that have adapted to mangrove forests by accumulating PHAs. The production of polyesters might therefore be an integral part of the carbon cycle in mangrove forests. Three of the strains (ND153, ND97, and QN194) isolated from the Vietnamese forests were identified as Bacillus species, while other five strains (QN187, ND199, ND218, ND240, and QN271) were phylogenetically close related to the ?-proteobacterium Yangia pacifica. These strains were found to accumulate PHAs in noticeable amounts. Polymer inclusions and chemical structure were studied by transmission electron microscopy and proton nuclear magnetic resonance (NMR) spectroscopy analyses, respectively. Strains ND153, ND97, QN194, QN187, ND240, and QN271 synthesized poly(3-hydroxybutyrate) (PHB) from glucose, whereas strains ND199 and ND218 synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from this carbohydrate. With the exception of strain QN194, the strains accumulated PHBV when a combination of glucose and propionate was included in the culture medium. The polymer yields and cell growth reached by one Bacillus isolate, strain ND153, and one Gram-negative bacterium, strain QN271, were high and worth to be researched further. For experiments performed in shake flasks, strain ND153 reached a maximum PHBV yield of 71 wt% and a cell dry weight (CDW) of 3.6 g/L while strain QN271 attained a maximum PHB yield of 48 wt% and a CDW of 5.1 g/L. Both strain ND153 and strain QN271 may only represent a case in point that exemplifies of the potential that mangrove forests possess for the discovery of novel halophilic and halotolerant microorganisms able to synthesize different types of biopolyesters. PMID:23233461

  20. Fabrication techniques for polybenzimidazole composites

    NASA Technical Reports Server (NTRS)

    Parker, J. A.; Winkler, E. L.; Kourtides, D.; Marks, B. S.

    1973-01-01

    Performance of polybenzimidazole composites as ablation shields can be substantially improved by thermal crosslinking. Program was designed to develop new processing methods and techniques for fabrication of polybenzimidazole composites. Report, which describes fabrication in detail, also includes specification and manufacturing standards.

  1. Fabrication of implantable microshunt using

    E-print Network

    the last structural layer, the cover of the channels. This method enhanced the electroplating process fabrication technique can be extended to many fluidic devices. Microfluidic device manufacturers employ many MEMS fabrication methods to build embedded channels, such as wafer bonding, electroplating with thick

  2. CW RFQ fabrication and engineering

    SciTech Connect

    Schrage, D.; Young, L.; Roybal, P. [and others

    1998-12-31

    The design and fabrication of a four-vane RFQ to deliver a 100 mA CW proton beam at 6.7 MeV is described. This linac is an Oxygen-Free Electrolytic (OFE) copper structure 8 m in length and was fabricated using hydrogen furnace brazing as the joining technology.

  3. Fabrication of Complex Metallic Nanostructures

    E-print Network

    Prentiss, Mara

    , Cambridge, Massachusetts 02138 T his article describes several routes to fabricate complex metallic nano and materials with which conventional methods of nano- fabrication (e.g., EUV or X-ray photolithogra- phy, e of copies of a nanostructure). It thus provides a new capability to nanofabrication. In this tech- nique, we

  4. Laser modification of polyamide fabrics

    NASA Astrophysics Data System (ADS)

    Bahtiyari, M. ?.

    2011-02-01

    A new method for the modification of the properties of polyamide fabric, based on exposure to the output from a CO 2 laser, has been investigated. It was found that, after laser modification of polyamide fabric, the dyeability of fabric was increased significantly, while the bursting strength was decreased. The reasons for this drastic increase in dyeability of polyamide fabrics have been analyzed with the help of FTIR and iodine sorption methods, revealing a relationship with a decrease in the crystallinity of the polyamide. It was observed that, as the laser modification of the fabric was carried out with low intensity, the concentration of free amino groups, which are necessary during dyeing with acid and reactive dyes, increased.

  5. Development of a Polyester Coating Combining Antithrombogenic and Cell Adhesive Properties: Influence of Sequence and Surface Density of Adhesion Peptides.

    PubMed

    Noel, Samantha; Hachem, Ahmed; Merhi, Yahye; De Crescenzo, Gregory

    2015-06-01

    Biofunctionalization strategies have been developed to improve small-diameter vascular grafts. However, a fully successful coating featuring antithrombogenic properties while allowing for endothelialization has not been achieved yet. In this report, we explored the combination of low-fouling polyethylene glycol (PEG) and adhesion peptides, namely, RGD, YIGSR, and REDV, grafted on top of polyvinylamine (PVAm)-coated polyester. The peptides were grafted over a wide range of density (ca. 20-2000 pmol/cm(2)) on top of a dense PEG underlayer. The coating performances were assessed through HUVEC adhesion, platelet attachment, and protein adsorption, which were all drastically diminished on PEG-coated samples. RGD exhibited the expected high adhesive properties, toward both HUVEC and platelets. REDV had no effect neither on platelet attachment, as expected, nor on HUVEC adhesion, in contrast with previous reports. YIGSR was the most promising sequence even though its combination with other agents should be explored to further decrease thrombogenicity for vascular graft applications. PMID:25877934

  6. Synthesis, z-scan and degenerate four wave mixing characterization of certain functionalized photosensitive polyesters containing ortho-hydroxyazo chromophores

    NASA Astrophysics Data System (ADS)

    Jayakrishnan, K.; Siji Narendran, N. K.; Sreejith, P.; Joseph, Antony; Chandrasekharan, K.; Purushothaman, E.

    2015-07-01

    The preparation and NLO characterization of photosensitive polyesters containing azoaromatic residues in the molecular backbone, functionalized with orthohydroxy chromophores is presented. Samples were studied for its UV-vis absorption, FT-IR and intensity dependent nonlinear absorption properties. Nonlinear characterization was carried out with z-scan using frequency doubled, Q-switched Nd:YAG laser operating at 532 nm. The closed aperture z-scan spectra reveal the self defocusing effects of the samples with negative nonlinearity coefficient (n2) showing values as high as -1.28 × 10-10 (esu) for certain samples and the corresponding third order susceptibility coefficient of the order of 29.9 × 10-12 (esu). Degenerate four wave mixing technique was employed to substantiate the findings. The numerical fits show that the molecules exhibit reverse saturable absorption. A study of beam fluence dependence of nonlinear absorption coefficient (?eff) has been presented. All phenomena indicate that molecules are reverse saturable absorbers whose optical limiting property gets enhanced with increasing conjugation length.

  7. Thermal characterization of composites made up of magnetically aligned carbonyl iron particles in a polyester resin matrix

    NASA Astrophysics Data System (ADS)

    Medina-Esquivel, R. A.; Zambrano-Arjona, M. A.; Mendez-Gamboa, J. A.; Yanez-Limon, J. M.; Ordonez-Miranda, J.; Alvarado-Gil, J. J.

    2012-03-01

    The thermal characterization of composites made up by magnetically aligned carbonyl iron micro-sized particles embedded in a polyester resin matrix is performed using photothermal radiometry technique. The measured experimental data show that the thermal conductivity and thermal diffusivity of the composite, in the direction of the applied magnetic field, increase with the concentration of the particles and are enhanced with respect to their corresponding values for a random distribution of the particles. This thermal enhancement has a maximum at a concentration of particles of 10% and is very low at small and high iron volume fractions, such that for particles concentrations of about 40%, the composite thermal conductivity reduces to its values for random particles. This behavior indicates that for high volume fractions, the effect of the microparticles concentration plays a dominant role over the effect of their alignment. It is shown that the thermal conductivity of the composite can be modeled in terms of the Nielsen model, under an appropriate parameterization of the form factor of the particles. The results of this work could be highly useful for improving the thermal performance of mechanical and electronic devices involving composite materials.

  8. Thermal performance measurements of a 100 percent polyester MLI (multilayer insulation) system for the Superconducting Super Collider

    SciTech Connect

    Boroski, W.N.; Gonczy, J.D.; Niemann, R.C.

    1989-09-01

    Thermal performance measurements of a 100 percent polyester multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) were conducted in a Heat Leak Test Facility (HLTF) under three experimental test arrangements. Each experiment measured the thermal performance of a 32-layer MLI blanket instrumented with twenty foil sensors to measure interstitial layer temperatures. Heat leak values and sensor temperatures were monitored during transient and steady state conditions under both design and degraded insulating vacuums. Heat leak values were measured using a heatmeter. MLI interstitial layer temperatures were measured using Cryogenic Linear Temperature Sensors (CLTS). Platinum resistors monitored system temperatures. High vacuum was measured using ion gauges; degraded vacuum employed thermocouple gauges. A four-wire system monitored instrumentation sensors and calibration heaters. An on-line computerized data acquisition system recorded and processes data. This paper reports on the instrumentation and experimental preparation used in carrying out these measurements. In complement with this paper is an associate paper bearing the same title head, but with the title extension Part 2: Laboratory results (300K--80K). 13 refs., 7 figs.

  9. Biodegradable poly(ester urethane)urea elastomers with variable amino content for subsequent functionalization with phosphorylcholine.

    PubMed

    Fang, Jun; Ye, Sang-Ho; Shankarraman, Venkat; Huang, Yixian; Mo, Xiumei; Wagner, William R

    2014-11-01

    While surface modification is well suited for imparting biomaterials with specific functionality for favorable cell interactions, the modification of degradable polymers would be expected to provide only temporary benefit. Bulk modification by incorporating pendant reactive groups for subsequent functionalization of biodegradable polymers would provide a more enduring approach. Towards this end, a series of biodegradable poly(ester urethane)urea elastomers with variable amino content (PEUU-NH2 polymers) were developed. Carboxylated phosphorycholine was synthesized and conjugated to the PEUU-NH2 polymers for subsequent bulk functionalization to generate PEUU-PC polymers. Synthesis was verified by proton nuclear magnetic resonance, X-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The impact of amine incorporation and phosphorylcholine conjugation was shown on mechanical, thermal and degradation properties. Water absorption increased with increasing amine content, and further with PC conjugation. In wet conditions, tensile strength and initial modulus generally decreased with increasing hydrophilicity, but remained in the range of 5-30 MPa and 10-20 MPa, respectively. PC conjugation was associated with significantly reduced platelet adhesion in blood contact testing and the inhibition of rat vascular smooth muscle cell proliferation. These biodegradable PEUU-PC elastomers offer attractive properties for applications as non-thrombogenic, biodegradable coatings and for blood-contacting scaffold applications. Further, the PEUU-NH2 base polymers offer the potential to have multiple types of biofunctional groups conjugated onto the backbone to address a variety of design objectives. PMID:25132273

  10. Surface modification of electrospun polyester nanofibers with cyclodextrin polymer for the removal of phenanthrene from aqueous solution.

    PubMed

    Kayaci, Fatma; Aytac, Zeynep; Uyar, Tamer

    2013-10-15

    Surface modified electrospun polyester (PET) nanofibers with cyclodextrin polymer (CDP) were produced (PET/CDP). CDP formation onto electrospun PET nanofibers was achieved by polymerization between citric acid (CTR, crosslinking agent) and cyclodextrin (CD). Three different types of native CD (?-CD, ?-CD and ?-CD) were used to form CDP. Water-insoluble crosslinked CDP coating was permanently adhered onto the PET nanofibers. SEM imaging indicated that the nanofibrous structure of PET mats was preserved after CDP surface modification process. PET/CDP nanofibers have shown rougher/irregular surface and larger fiber diameter when compared to untreated PET nanofibers. The surface analyses of PET/CDP nanofibers by XPS elucidated that CDP was present on the fiber surface. DMA analyses revealed the enhanced mechanical properties for PET/CDP where PET/CDP nanofibers have shown higher storage modulus and higher glass transition temperature compared to untreated PET nanofibers. The surface area of the PET/CDP nanofibers investigated by BET measurements showed slight decrease due to the presence of CDP coating compared to pristine PET nanofibers. Yet, it was observed that PET/CDP nanofibers were more efficient for the removal of phenanthrene as a model polycyclic aromatic hydrocarbon (PAH) from aqueous solution when compared to pristine PET nanofibers. Our findings suggested that PET/CDP nanofibers can be a very good candidate as a filter material for water purification and waste treatment owing to their very large surface area as well as inclusion complexation capability of surface associated CDP. PMID:23959248

  11. Techniques of Electrode Fabrication

    NASA Astrophysics Data System (ADS)

    Guo, Liang; Li, Xinyong; Chen, Guohua

    Electrochemical applications using many kinds of electrode materials as an advanced oxidation/reduction technique have been a focus of research by a number of groups during the last two decades. The electrochemical approach has been adopted successfully to develop various environmental applications, mainly including water and wastewater treatment, aqueous system monitoring, and solid surface analysis. In this chapter, a number of methods for the fabrication of film-structured electrode materials were selectively reviewed. Firstly, the thermal decomposition method is briefly described, followed by introducing chemical vapor deposition (CVD) strategy. Especially, much attention was focused on introducing the methods to produce diamond novel film electrode owing to its unique physical and chemical properties. The principle and influence factors of hot filament CVD and plasma enhanced CVD preparation were interpreted by refereeing recent reports. Finally, recent developments that address electro-oxidation/reduction issues and novel electrodes such as nano-electrode and boron-doped diamond electrode (BDD) are presented in the overview.

  12. Fabrication of cotton fabric with superhydrophobicity and flame retardancy.

    PubMed

    Zhang, Ming; Wang, Chengyu

    2013-07-25

    A simple and facile method for fabricating the cotton fabric with superhydrophobicity and flame retardancy is described in the present work. The cotton fabric with the maximal WCA of 160° has been prepared by the covalent deposition of amino-silica nanospheres and the further graft with (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane. The geometric microstructure of silica spheres was measured by transmission electron microscopy (TEM). The cotton textiles before and after treatment were characterized by using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The wetting behavior of cotton samples was investigated by water contact angle measurement. Moreover, diverse performances of superhydrophobic cotton textiles have been evaluated as well. The results exhibited the outstanding superhydrophobicity, excellent waterproofing durability and flame retardancy of the cotton fabric after treatment, offering a good opportunity to accelerate the large-scale production of superhydrophobic textiles materials for new industrial applications. PMID:23768579

  13. Analysis of the failure of fiberglass-fabric-reinforced silicone-rubber circular pressure-relief-duct expansion/contraction joint seals at Pickering NGS Unit 6 and 7 during the 1990 as-found pressure test. Report No. 90-172-K

    SciTech Connect

    Lewak, R.J.

    1990-01-01

    This report details the examination of the failed areas of the Units 6 and 7 joint seals as found in the pressure test outages at the Pickering Nuclear Generating Station during May 1990. In addition, samples of material from Units 6 and 7 in the failed area and other areas were tested for tensile strength and hardness along with the new polyester fabric reinforced silicone rubber seal material in order to determine the relative strength and flexibility of the old seal as compared with the new.

  14. Fabricating Copper Nanotubes by Electrodeposition

    NASA Technical Reports Server (NTRS)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  15. Electrophoretic Deposition for Fabricating Microbatteries

    NASA Technical Reports Server (NTRS)

    West, William; Whitacre, Jay; Bugga, Ratnakumar

    2003-01-01

    An improved method of fabrication of cathodes of microbatteries is based on electrophoretic deposition. Heretofore, sputtering (for deposition) and the use of photoresist and liftoff (for patterning) have been the primary methods of fabricating components of microbatteries. The volume of active electrode material that can be deposited by sputtering is limited, and the discharge capacities of prior microbatteries have been limited accordingly. In addition, sputter deposition is slow. In contrast, electrophoretic deposition is much faster and has shown promise for increasing discharge capacities by a factor of 10, relative to those of microbatteries fabricated by prior methods.

  16. Use of atmospheric pressure plasma to confer durable water repellent functionality and antimicrobial functionality on cotton\\/polyester blend

    Microsoft Academic Search

    Rachel Davis; Ahmed El-Shafei; Peter Hauser

    2011-01-01

    A non-thermal, high density atmospheric plasma glow discharge treatment was used to impart functionality to cotton\\/polyethylene terephthalate (PET) fabric to furnish a surface that is water repellent and then antimicrobial only.In this work, cotton\\/PET (50\\/50%) blend fabric was treated with a water repellent treatment through activating the surface with plasma, depositing a vaporized fluorocarbon based monomers, 1,1,2,2-tetrahydroperfluorodecyl acrylate (THPFDA) and

  17. Microdisk fabrication by emulsion evaporation 

    E-print Network

    Wong, Susanna Wing Man

    2007-09-17

    with precise control of particle size and shape has not yet succeeded. In this thesis, we show an experimental strategy of using microfluidic technique to fabricate homogeneous �±-eicosene microemulsions with chloroform in an aqueous solution of sodium...

  18. Film Fabrication Technologies at NREL

    NASA Technical Reports Server (NTRS)

    Mcconnell, Robert D.

    1993-01-01

    The National Renewable Energy Laboratory (NREL) has extensive capabilities for fabricating a variety of high-technology films. Much of the in-house work in NREL's large photovoltaics (PV) program involves the fabrication of multiple thin-film semiconducting layers constituting a thin-film PV device. NREL's smaller program in superconductivity focuses on the fabrication of superconducting films on long, flexible tape substrates. This paper focuses on four of NREL's in-house research groups and their film fabrication techniques, developed for a variety of elements, alloys, and compounds to be deposited on a variety of substrates. As is the case for many national laboratories, NREL's technology transfer efforts are focusing on Cooperative Research and Development Agreements (CRADA's) between NREL researchers and private industry researchers.

  19. Microdisk fabrication by emulsion evaporation

    E-print Network

    Wong, Susanna Wing Man

    2007-09-17

    with precise control of particle size and shape has not yet succeeded. In this thesis, we show an experimental strategy of using microfluidic technique to fabricate homogeneous �±-eicosene microemulsions with chloroform in an aqueous solution of sodium...

  20. Reasonable computing for architectural fabrication

    E-print Network

    Villalon, Rachelle B. (Rachelle Bentajado)

    2008-01-01

    The use of digital fabrication tools in the architecture industry serve a particular group of individuals whose familiarity of the tools are by trade skill. Machines lack the understanding of people in its ability to ...

  1. Silicone nanocomposite coatings for fabrics

    NASA Technical Reports Server (NTRS)

    Eberts, Kenneth (Inventor); Lee, Stein S. (Inventor); Singhal, Amit (Inventor); Ou, Runqing (Inventor)

    2011-01-01

    A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

  2. Silicon, iron and titanium doped calcium phosphate-based glass reinforced biodegradable polyester composites as bone analogous materials

    NASA Astrophysics Data System (ADS)

    Shah Mohammadi, Maziar

    Bone defects resulting from disease or traumatic injury is a major health care problem worldwide. Tissue engineering offers an alternative approach to repair and regenerate bone through the use of a cell-scaffold construct. The scaffold should be biodegradable, biocompatible, porous with an open pore structure, and should be able to withstand the applied forces. Phosphate-based glasses (PGs) may be used as reinforcing agents in degradable composites since their degradation can be predicted and controlled through their chemistry. This doctoral dissertation describes the development and evaluation of PGs reinforced biodegradable polyesters for intended applications in bone augmentation and regeneration. This research was divided into three main objectives: 1) Investigating the composition dependent properties of novel PG formulations by doping a sodium-free calcium phosphate-based glass with SiO2, Fe2O3, and TiO2. Accordingly, (50P2 O5-40CaO- xSiO2-(10-x)Fe2O3, where x = 10, 5 and 0 mol.%) and (50P2O5-40CaO-xSiO 2-(10-x)TiO2 where x = 10, 7, 5, 3 and 0 mol.%) formulations were developed and characterised. SiO2 incorporation led to increased solubility, ion release, pH reduction, as well as hydrophilicity, surface energy, and surface polarity. In contrast, doping with Fe2O 3 or TiO2 resulted in more durable glasses, and improved cell attachment and viability. It was hypothesised that the presence of SiO 2 in the TiO2-doped formulations could up-regulate the ionic release from the PG leading to higher alkaline phosphatase activity of MC3T3-E1 cells. 2) Incorporating Si, Fe, and Ti doped PGs as fillers, either as particulates (PGPs) or fibres (PGFs), into biodegradable polyesters (polycaprolactone (PCL) and semi-crystalline and amorphous poly(lactic acid) (PLA and PDLLA)) with the aim of developing degradable bone analogous composites. It was found that PG composition and geometry dictated the weight loss, ionic release, and mechanical properties of the composites. It was also hypothesised that a potential reaction between Si and the ester bond led to the formation of carboxylate by-products resulting in a lower molecular weight polymer, thus affecting the mechanical properties of the composites. Cytocompatibility assessment with MC3T3-E1 pre-osteoblasts showed that these composites were cytocompatible, and cell alignment along the PGFs was observed possibly due to their favourable ionic release properties. 3) Investigating the solid-state foaming using carbon dioxide (CO 2) of PDLLA-PGP composites with up to 30 vol.% filler content. While PDLLA foams resulted in 92% porosity, the porosity of the composites ranged between 79 and 91% which decreased with PGP content. In addition, a reduction in pore size was observed with increasing PGP content; however, the pore size maintained its range of 200-500 ?m in all composite foams, suitable for bone tissue engineering applications. The percentage of open pores increased significantly with PGP content (up to 78% at 30 vol.% PGP). Compressive strength and modulus of PDLLA-PGP foams showed up to approximately 3-fold increase at 30 vol.% PGP content compared to neat PDLLA foams.

  3. Formation of polyesters consisting of medium-chain-length 3-hydroxyalkanoic acids from gluconate by Pseudomonas aeruginosa and other fluorescent pseudomonads.

    PubMed Central

    Timm, A; Steinbüchel, A

    1990-01-01

    Pseudomonas aeruginosa PAO and 15 other strains of this species synthesized a polyester with 3-hydroxydecanoate as the main constituent (55 to 76 mol%) if the cells were cultivated in the presence of gluconate and if the nitrogen source was exhausted; 3-hydroxyhexanoate, 3-hydroxyoctanoate, and 3-hydroxydodecanoate were minor constituents of the polymer. The polymer was deposited in granules within the cell and amounted to 70% of the cell dry matter in some strains. Among 55 different strains of 41 Pseudomonas species tested, P. aureofaciens (21.6% of cellular dry matter), P. citronellolis (78.0%), P. chlororaphis (8.5%), P. marginalis (11.4%), P. mendocina (50.7%), P. putida (33.5%), and Pseudomonas sp. strain DSM 1650 (54.6%) accumulated this type of polymer at significant levels (greater than 5%) during cultivation on gluconate. In two strains of P. facilis and P. fluorescens, as well as in one strain of P. syringae, this polymer was detected as a minor constituent (much less than 5%). All other strains accumulated either poly(3-hydroxybutyrate) or a polymer consisting mainly of 3-hydroxyoctanoate with octanoate but no polyester with gluconate as the carbon source. Only a few species (e.g., P. stutzeri) were unable to accumulate poly(hydroxyalkanoic acids) (PHA) at all. These results indicated that the formation of PHA depends on a pathway which is distinct from all other known PHA-biosynthetic pathways. The polyesters accumulated by gluconate- or octanoate-grown cells of recombinant strains of P. aeruginosa and P. putida, which harbored the Alcaligenes eutrophus poly(3-hydroxybutyrate)biosynthetic genes, contained 3-hydroxybutyrate as an additional constituent. Images PMID:2125185

  4. Nondestructive identification of dye mixtures in polyester and cotton fibers using raman spectroscopy and ultraviolet-visible (UV-Vis) microspectrophotometry.

    PubMed

    Was-Gubala, Jolanta; Starczak, Roza

    2015-01-01

    Presented in this paper is an assessment of the applicability of Raman spectroscopy and microspectrophotometry (MSP) in visible and ultraviolet light (UV-Vis) in the examination of textile fibers dyed with mixtures of synthetic dyes. Fragments of single polyester fibers, stained with ternary mixtures of disperse dyes in small mass concentrations, and fragments of single cotton fibers, dyed with binary or ternary mixtures of reactive dyes, were subjected to the study. Three types of excitation sources, 514, 633, and 785 nm, were used during Raman examinations, while the MSP study was conducted in the 200 to 800 nm range. The results indicate that the capabilities for discernment of dye mixtures are similar in the spectroscopic methods that were employed. Both methods have a limited capacity to distinguish slightly dyed polyester fiber; additionally, it was found that Raman spectroscopy enables identification of primarily the major components in dye mixtures. The best results, in terms of the quality of Raman spectra, were obtained using an excitation source from the near infrared. MSP studies led to the conclusion that polyester testing should be carried out in the range above 310 nm, while for cotton fibers there is no limitation or restriction of the applied range. Also, MSP UV-Vis showed limited possibilities for discriminatory analysis of cotton fibers dyed with a mixture of reactive dyes, where the ratio of the concentration of the main dye used in the dyeing process to minor dye was higher than four. The results presented have practical applications in forensic studies, inter alia. PMID:25588115

  5. Long-term field performance of a polyester-based long-lasting insecticidal mosquito net in rural Uganda

    PubMed Central

    Kilian, Albert; Byamukama, Wilson; Pigeon, Olivier; Atieli, Francis; Duchon, Stephan; Phan, Chi

    2008-01-01

    Background In order to evaluate whether criteria for LLIN field performance (phase III) set by the WHO Pesticide Evaluation Scheme are met, first and second generations of one of these products, PermaNet®, a polyester net using the coating technology were tested. Methods A randomized, double blinded study design was used comparing LLIN to conventionally treated nets and following LLIN for three years under regular household use in rural conditions. Primary outcome measures were deltamethrin residue and bioassay performance (60 minute knock-down and 24 hour mortality after a three minute exposure) using a strain of Anopheles gambiae s.s. sensitive to pyrethroid insecticides. Results Baseline concentration of deltamethrin was within targets for all net types but was rapidly lost in conventionally treated nets and first generation PermaNet® with median of 0.7 and 2.5 mg/m2 after six months respectively. In contrast, second generation PermaNet® retained insecticide well and had 41.5% of baseline dose after 36 months (28.7 mg/m2). Similarly, vector mortality and knockdown dropped to 18% and 70% respectively for first generation LLIN after six months but remained high (88.5% and 97.8% respectively) for second generation PermaNet® after 36 months of follow up at which time 90.0% of nets had either a knockdown rate ? 95% or mortality rate ? 80%. Conclusion Second generation PermaNet® showed excellent results after three years of field use and fulfilled the WHOPES criteria for LLIN. Loss of insecticide on LLIN using coating technology under field conditions was far more influenced by factors associated with handling rather than washing. PMID:18355408

  6. Novel 18F labeling strategy for polyester-based NPs for in vivo PET-CT imaging.

    PubMed

    Di Mauro, Primiano Pio; Gómez-Vallejo, Vanessa; Baz Maldonado, Zuriñe; Llop Roig, Jordi; Borrós, Salvador

    2015-03-18

    Drug-loaded nanocarriers and nanoparticulate systems used for drug release require a careful in vivo evaluation in terms of physicochemical and pharmacokinetic properties. Nuclear imaging techniques such as positron emission tomography (PET) are ideal and noninvasive tools to investigate the biodistribution and biological fate of the nanostructures, but the incorporation of a positron emitter is required. Here we describe a novel approach for the (18)F-radiolabeling of polyester-based nanoparticles. Our approach relies on the preparation of the radiolabeled active agent 4-[(18)F]fluorobenzyl-2-bromoacetamide ([(18)F]FBBA), which is subsequently coupled to block copolymers under mild conditions. The labeled block copolymers are ultimately incorporated as constituent elements of the NPs by using a modified nano coprecipitation method. This strategy has been applied in the current work to the preparation of peptide-functionalized NPs with potential applications in drug delivery. According to the measurements of particle size and zeta potential, the radiolabeling process did not result in a statistically significant alteration of the physicochemical properties of the NPs. Moreover, radiochemical stability studies showed no detachment of the radioactivity from NPs even at 12 h after preparation. The radiolabeled NPs enabled the in vivo quantification of the biodistribution data in rats using a combination of imaging techniques, namely, PET and computerized tomography (CT). Low accumulation of the nanoparticles in the liver and their elimination mainly via urine was found. The different biodistribution pattern obtained for the "free" radiolabeled polymer suggests chemical and radiochemical integrity of the NPs under investigation. The strategy reported here may be applied to any polymeric NPs containing polymers bearing a nucleophile, and hence our novel strategy may find application for the in vivo and noninvasive investigation of a wide range of NPs. PMID:25710619

  7. Comparison of various advanced oxidation processes and chemical treatment methods for COD and color removal from a polyester and acetate fiber dyeing effluent

    Microsoft Academic Search

    N. Azbar; T. Yonar; K. Kestioglu

    2004-01-01

    In this paper, a comparison of various advanced oxidation processes (O3, O3\\/UV, H2O2\\/UV, O3\\/H2O2\\/UV, Fe2+\\/H2O2) and chemical treatment methods using Al2(SO4)3·18H2O, FeCl3 and FeSO4 for the chemical oxygen demand (COD) and color removal from a polyester and acetate fiber dyeing effluent is undertaken. Advanced oxidation processes (AOPs) showed a superior performance compared to conventional chemical treatment, which maximum achievable color

  8. Fabric Performance in Clothing and Clothing Manufacture

    Microsoft Academic Search

    S. Kawabata; Masako Niwa

    1989-01-01

    After the performance of clothing fabric in use has been satisfied to some extent, consumers seek better-quality, that is, more comfortable, fabrics. Fabric performance in relation to ‘better fitting to the human body’ is an essential requirement of clothing materials. From the mechanical-comfort viewpoint, textile producers and consumers have evaluated this kind of fabric performance by a subjective method, called

  9. Fabrication of micro-optical devices

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Marley, J.; Gal, George; Purdy, Don

    1993-01-01

    We have fabricated a variety of micro-optic components including Fresnel and non-Frensel lenses, off-axis and dispersive lenses with binary stepped contours, and analog contours. Process details for all lens designs fabricated are given including multistep photolithography for binary fabrication and grayscale mask photolithography for analog fabrication. Reactive ion etching and ion beam milling are described for the binary fabrication process, while ion beam milling was used for the analog fabrication process. Examples of micro-optic components fabricated in both Si and CdTe substrates are given.

  10. Poly(acrylic acid)/poly(ethylene glycol) adduct for attaining multifunctional cellulosic fabrics.

    PubMed

    Ibrahim, N A; Amr, A; Eid, B M; Mohamed, Z E; Fahmy, H M

    2012-06-20

    Aqueous polymerization of partially neutralized acrylic acid (AA) along with polyethylene glycol (PEG-600) at AA/PEG-600 mass ratio 3/1 using ammonium persulfate as initiator under proper conditions results in formation of PAA/PEG-600 adduct. The structure of the adduct was confirmed by FT-IR spectra. The potential applications of the prepared adduct in: sizing, durable hand building of cotton cellulose, as well as in functional finishing of cellulose containing fabrics, i.e. cotton, viscose and cotton/polyester, with Ag- or TiO2-nanoparticles were investigated. The modified substrates using the prepared adduct showed a remarkable improvement in their sizing, hand building and/or functional properties, i.e. antibacterial, anti-UV, and self cleaning, in addition to durability to wash. TEM images of the prepared nano-particles, SEM images of the untreated and treated substrates, as well as EDX spectra to analyze the surface elemental compositions were examined. The tentative mechanisms were also suggested. PMID:24750770

  11. A facile method to fabricate superhydrophobic cotton fabrics

    NASA Astrophysics Data System (ADS)

    Zhang, Ming; Wang, Shuliang; Wang, Chengyu; Li, Jian

    2012-11-01

    A facile and novel method for fabricating superhydrophobic cotton fabrics is described in the present work. The superhydrophobic surface has been prepared by utilizing cationic poly (dimethyldiallylammonium chloride) and silica particles together with subsequent modification of (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane. The size distribution of silica particles was measured by Particle Size Analyzer. The cotton textiles before and after treatment were characterized by using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The wetting behavior of cotton samples was investigated by water contact angle measurement. Moreover, the superhydrophobic durability of coated cotton textiles has been evaluated by exposure, immersion and washing tests. The results show that the treated cotton fabrics exhibited excellent chemical stability and outstanding non-wettability with the WCA of 155 ± 2°, which offers an opportunity to accelerate the large-scale production of superhydrophobic textiles materials for new industrial applications.

  12. MEMS: fabrication of cryogenic bolometers

    NASA Astrophysics Data System (ADS)

    Kunert, J.; Anders, S.; May, T.; Zakosarenko, V.; Zieger, G.; Kreysa, E.; Meyer, H.-G.

    2012-02-01

    Cryogenic bolometers are among the most sensitive devices for the detection of electromagnetic radiation in the submillimeter wavelength range. Such radiation is of interest for astronomical observations as well as for security checks. We describe how we fabricate an array of these bolometers. Standard contact lithography is sufficient for these relatively coarse features. To increase the sensitivity, it is imperative to weaken the thermal link between the thermistors (the sensing devices) and the temperature bath. This is achieved by placing them on a silicon nitride membrane that is structured so that the thermistors are placed on a platform which is held only by a few beams. The fabrication process does not require sophisticated lithographic techniques, but special care to achieve the desired yield of 100 % intact bolometers in one array. We discuss bolometer basics and requirements for our applications, critical fabrication issues, and show results of complete systems built for a radio telescope and for security cameras.

  13. Copolymerization of 2-methylene-1,3-dioxepane and glycidyl methacrylate, a well-defined and efficient process for achieving functionalized polyesters for covalent binding of bioactive molecules.

    PubMed

    Undin, Jenny; Finne-Wistrand, Anna; Albertsson, Ann-Christine

    2013-06-10

    The understanding of cell-material interactions is important for creating personalized implants for tissue engineering. This has resulted in an interest in developing polymers with functional groups with the possibility of controlling the macromolecular surface. We have in a one-pot reaction synthesized a series of amorphous and degradable polyester-based copolymers with active functional groups by copolymerization of 2-methylene-1,3-dioxepane and glycidyl methacrylate. The properties of the final polymers were varied by varying the feed ratios of the monomers, and it was seen that it was possible to control the amount of active functional groups. The resulting epoxy-functionalized polyester was further modified by covalent immobilization of heparin. The heparinization was done in order, in a future aspect, to enhance the osteogenic differentiation of mesenchymal stem cells. Heparin binds directly with the growth factor bone morphogenetic protein-2 and helps to retain its activity. The molecular structure of the copolymers was characterized by nuclear magnetic resonance, size exclusion chromatography, and Fourier transform infrared spectroscopy. Differential scanning calorimetry and tensile testing showed that the monomer feed ratio had a great influence on the properties of the final polymer and that it thus was possible to control the mechanical properties to suit an intended application. The presence of heparin was verified by toluidine blue staining, and all of the films tested showed positive signals for heparin. PMID:23641914

  14. Effects of hydrophobic drug polyesteric core interactions on drug loading and release properties of poly(ethylene glycol) polyester poly(ethylene glycol) triblock core shell nanoparticles

    NASA Astrophysics Data System (ADS)

    Khoee, Sepideh; Hassanzadeh, Salman; Goliaie, Bahram

    2007-05-01

    BAB amphiphilic triblock copolymers consisting of poly(ethylene glycol) (B) (PEG) as the hydrophilic segment and different polyesters (A) as the hydrophobic block were prepared by a polycondensation reaction as efficient model core-shell nanoparticles to assay the effect of interactions between the hydrophobic drug and the polyesteric core in terms of drug loading content and release profile. PEG-poly(hexylene adipate)-PEG (PEG-PHA-PEG) and PEG-poly(butylene adipate)-PEG (PEG-PBA-PEG) to PEG-poly(ethylene adipate)-PEG (PEG-PEA-PEG) core-shell type nanoparticles entrapping quercetin (an anticarcinogenic, allergy inhibitor and antibacterial agent), were prepared by a nanoprecipitation method and characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and x-ray diffraction (XRD) techniques. It was found that the obtained nanoparticles showed a smooth surface and spherical shape with controllable sizes in the range of 64-74 nm, while drug loading varied from 7.24% to 19% depending on the copolymer composition and the preparation conditions. The in vitro release behaviour exhibited a sustained release and was affected by the polymer-drug interactions. UV studies revealed the presence of hydrogen bonding as the main existing interaction between quercetin and polyesters in the nanosphere cores.

  15. Removing Stains from Washable Fabrics

    E-print Network

    Beard, Ann Vanderpoorten

    1988-01-01

    , then rinse. If color or texture is affected, do not use this product to treat the stain. ? When treating a spot, place it face down on white paper towels or a soft, clean, white cloth pad. Apply stain remover to the wrong side of the stain so... that the stain will be forced off the surface and not through the fabric. An eyedropper is useful for applying removers. Replace the towels or cloth pad frequently to prevent the stain from transfer ring back onto the fabric. ? Sponge by applying stain...

  16. Fabrication of superhydrophobic cotton fabrics by silica hydrosol and hydrophobization

    Microsoft Academic Search

    Lihui Xu; Wei Zhuang; Bi Xu; Zaisheng Cai

    2011-01-01

    Superhydrophobic cotton fabrics were prepared by the incorporation of silica nanoparticles and subsequent hydrophobization with hexadecyltrimethoxysilane (HDTMS). The silica nanoparticles were synthesized via sol–gel reaction with methyl trimethoxy silane (MTMS) as the precursor in the presence of the base catalyst and surfactant in aqueous solution. As for the resulting products, characterization by particle size analyzer, scanning electron microscopy (SEM), scanning

  17. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS, BWF AMERICA, INC. GRADE 700 MPS POLYESTER FELT FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size for particles equal to or smaller than...

  18. Helical assembly, liquid crystalline behavior and crystallization of a nonracemic chiral main-chain liquid crystalline polyester and its monomers

    NASA Astrophysics Data System (ADS)

    Weng, Xin

    In this thesis, A non-racemic chiral main-chain liquid crystalline (LC) polyester was synthesized from (R)-(-)-4'-{o-[2-( p-hydroxy-o-nitrophenyloxy)-1-propyloxy]-1-undecyloxy}-4-biphenyl carboxylic acid via an A-B type condensation polymerization. The polymer was abbreviated as PET(R*-11) where eleven is the number of methylene units in the chain backbone. PET(R*-11) exhibited a LC chiral smectic C (SC*), a chiral smectic A (SA*) and a twist grain boundary Smectic A (TGBA*) phase with increasing temperatures as identified by differential scanning calorimetry, polarized optical microscopy, and wide angle X-ray diffraction (WAXD). Flat-elongated lamellae were observed in transmission electron microscopy (TEM) for thin-film melt crystallized samples. Its crystal structure was determined to be a monoclinic basic unit cell with a = 1.03 nm, b = 0.47 nm, c = 6.43 nm and gamma = 83° via selected area electron diffraction (SAED), and these measurements were confirmed by two-dimensional WAXD fiber patterns. Furthermore, SAED results showed that two kinds of crystal twins existed in this polymer: "micro-twinning" within one single lamellar crystal and "rotation-twinning" between two lamellae. This rotation-twinning was possibly a result of a mechanism of a soft epitaxy between two contacting (001) folded surfaces along the (3¯10) planes. Right-handed helical lamellar crystals were also found under the same crystallization conditions, and their pitch lengths were on the micrometer scale as observed by TEM and atomic force microscopy. The helical crystal structure was found to be identical to that of the flat-elongated counterparts. Dendritic crystals with fractal geometry were also obtained as the result of diffusion-controlled crystal growth. The phase structures of two monomers of PET(R*-11) were studied. One of them has carboxylic acid end group (named as K11-acid), while another has ester end group (named as Kl 1-ester). Kl 1-ester does not show any LC behavior, while cholesteric phase and Sc* phases can be obtained in K11-acid. The hydrogen-bonding between two carboxylic acid groups of K11-acid plays an important role in its liquid crystal phase formation. No helical crystals were observed in the monomers. These results might suggest that the enhanced chirality strength in the polymer chain of PET(R*-11) stabilize the helical structure in highly ordered crystals.

  19. Fabrication of metallic glass structures

    DOEpatents

    Cline, Carl F. (Walnut Creek, CA)

    1986-01-01

    Amorphous metal powders or ribbons are fabricated into solid shapes of appreciable thickness by the application of compaction energy. The temperature regime wherein the amorphous metal deforms by viscous flow is measured. The metal powders or ribbons are compacted within the temperature range.

  20. MCVD fiber fabrication system design

    Microsoft Academic Search

    K. Chida; Y. Terunuma; T. Edahiro; M. Okada

    1979-01-01

    The MCVD system for optical fiber fabrication was newly designed. A machine aided improved MCVD system was investigated, which consists of a precise glass working lathe, a stabilized gas blender, an oxy-hydrogen flame controller and a silica tube diameter controller. In addition, a computer controller is applicable for use to control the above mentioned system components. With this improved MCVD