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1

Tapered, tubular polyester fabric  

NASA Technical Reports Server (NTRS)

A tapered tubular polyester sleeve is described to serve as the flexible foundation for a spacesuit limb covering. The tube has a large end and a small end with a length to be determined. The ratio of taper is also determined by scale factors. All the warp yarns extend to the large end. A requisite number of warp yarns extend the full length of the sleeve. Other warp yarns extend from the large end but are terminated along the length of the sleeve. It is then woven with a filling yarn which extends in a full circle along the full length of the sleeve to thereby define the tapered sleeve. The sleeve after fabrication is then placed on a mandrel, heated in an oven, and then attached to the arm or other limb of the spacesuit.

Lapointe, Donat J. E. (inventor); Wright, Lawrence T. (inventor); Vincent, Laurence J. (inventor)

1987-01-01

2

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

E-print Network

Fabrication and characterization of biomimetic multichanneled crosslinked-urethane-doped polyester: Biomimetic scaffolds that replicate the native archi- tecture and mechanical properties of target tissues, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers

Chiao, Jung-Chih

3

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

4

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

NASA Astrophysics Data System (ADS)

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.

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

2015-04-01

5

Eco-friendly surface modification on polyester fabrics by esterase treatment  

NASA Astrophysics Data System (ADS)

Currently, traditional alkali deweighting technology is widely used to improve the hydrophilicity of polyester fabrics. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment. Esterase treatment, which is feasible in mild conditions with high selectivity, can provide a clean and efficient way for polyester modification. Under the optimum conditions, the polyester fabric hydrolysis process of esterase had a linear kinetics. X-ray photoelectron spectrometry (XPS) results showed that hydroxyl and carboxyl groups were produced only on the surface of modified fiber without changing the chemical composition of the bulk. These fibers exhibited much improved fabric wicking, as well as greatly improved oily stain removal performance. Compared to the harsh alkali hydrolysis, the enzyme treatment led to smaller weight loss and better fiber integrity. The esterase treatment technology is promising to produce higher-quality polyester textiles with an environmental friendly approach.

Wu, Jindan; Cai, Guoqiang; Liu, Jinqiang; Ge, Huayun; Wang, Jiping

2014-03-01

6

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

Microsoft Academic Search

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

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

2000-01-01

7

Ammonium Chloride as a Flame Retardant in a Polyester Fabric and its Detection  

Microsoft Academic Search

The effect of ammonium chloride as a nondurable finish on the flammability of 100% polyester fabric has been investigated. The laundered, bone-dried, weighed fabrics were impregnated with a suitable concentration of aqueous ammonium chloride solution by means of squeeze rolls and drying at 110°C for 30 min. They were then cooled in a desiccator, re-weighed in an analytical balance and kept

S. M. Mostashari; S. Z. Mostashari

2008-01-01

8

Physical Properties of Polyester Fabrics Treated with Nano, Micro and Macro Emulsion Silicones  

NASA Astrophysics Data System (ADS)

The processing of textile to achieve a particular handle is one of the most important aspects of finishing technology. Fabrics softeners are liquid composition added to washing machines during the rinse cycle to make clothes feel better to the touch. The first fabric softeners were developed by the textile industry during the early twentieth century. In this research polyester fabrics were treated with nano, micro and macro emulsion silicone softeners. Some of the physical properties of the treated fabric samples are discussed. The drapeability of treated samples was improved after treatment with nano silicone softeners. The colorimetric measurement of softener-treated fabrics is evaluated with a reflectance spectrophotometer. Moisture regain of treated samples is increased due to coating of silicone softeners. There is some increase in the weight of softener-treated samples. Samples treated with nano emulsion silicones gave better results compared to micro- and macro-emulsion treated ones.

Parvinzadeh, M.; Hajiraissi, R.

2007-08-01

9

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

PubMed

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

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

2013-01-30

10

Synthesis of PVDF ultrafiltration membranes supported on polyester fabrics for separation of organic matter from water  

NASA Astrophysics Data System (ADS)

Polyvinylidene flouride (PVDF) membranes supported on non-woven fabrics (NWF) of polyester are reported. The PVDF membranes were fabricated using the phase inversion method followed by modification of the active top layer of the PVDF thin film by adding polyvinylpyrolidone (PVP) into the cast solution. A PVDF resin was used with N- methyl-2-pyrrolidone (NMP) as a solvent. Sessile drop contact angle measurements and scanning electron microscopy (SEM) were used to study the physical properties of the membranes. Membrane rejection of humic acid was studied using a cross-flow membrane testing unit. The contact angle results revealed that the hydrophilicity of PVDF membranes increased as the PVP concentration was increased from 3 to 10 wt%. SEM analysis of the membranes revealed that the membrane pore sizes increased when PVP was added. AFM analysis also showed that membrane roughness changed when PVP was added. Total organic carbon (TOC) analysis of water samples spiked with humic acid was performed to test the rejection capacity of the membranes. Rejections of up to 97% were achieved for PVDF membranes supported on polyester NWF1, which had smaller thickness and higher permeability compared to polyester NWF2. The NWFs provided the high strength required for the membranes despite the modifications done on the PDVF surface and microstructure.

Mhlanga, Sabelo D.; Tshabalala, Tumelo G.; Nxumalo, Edward N.; Mamba, Bhekie B.

2014-08-01

11

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

SciTech Connect

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.

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

1995-12-01

12

Characterization of ZnO coated polyester fabrics for UV protection  

NASA Astrophysics Data System (ADS)

The textile industry aims to develop fabrics adapted to environmental conditions, in particular to UV radiation. Taking into account the demand for such materials, we prepare an inorganic-organic material, based on ZnO microparticles impregnation of polyester textiles, to perform combined UV-protection properties and high hydrophobicity. Scanning electron microscopy, UV reflectance, Impedance Spectroscopy, contact angle, air permeability, resistance to vapor transfer and tensile strength measurement are used for analysis of the surface and volume properties, related to the performance of the material under environmental conditions, as UV radiation, water and water vapors. The impregnation method ensures a good homogeneity and dispersion of ZnO microparticles into the textile polymeric matrix. The optimum level of impregnation of the fabrics is established to 3-5% ZnO, yielding stable properties, without overloading the fabric. The response of the coated polymer indicates better absorbing the UV radiation and dissipating the surface charge, time stability against UV and higher hydrophobic character, without modification of the mechanical properties, offering enhanced performance and comfort under environmental conditions.

Broasca, G.; Borcia, G.; Dumitrascu, N.; Vrinceanu, N.

2013-08-01

13

Impact damage and residual strengths of woven fabric glass\\/polyester laminates  

Microsoft Academic Search

Thick glass\\/polyester laminates of four different dimensions subject to low-velocity impact have been investigated using a guided drop-weight test rig with a flat-ended impactor in ascending energy order up to 3100 J. The characteristics of impact response and energy absorption have been determined by impact force and absorbed energy histories, and impact damage incurred was examined by cross-sectioning and ultrasonic

G. Zhou; D HITCHINGS

1996-01-01

14

Experimental Investigation of the Interface Behavior of Balanced and Unbalanced E-Glass/Polyester Woven Fabric Composite Laminates  

NASA Astrophysics Data System (ADS)

The aim of this work is to study the influence of weave structure on the crack growth behavior of thick E-glass/polyester woven fabric composites laminates. Two different types of laminates were fabricated: (i) balanced: plain weave (taffetas T)/chopped strand mat weave (M) [T/M]6 and (ii) unbalanced: 4-hardness satin weave (S)/chopped strand mat weave [S/M]7. In order to accurately predict damage criticality in such structures, mixed mode fracture toughness data is required. So, the experiments were conducted using standards delamination tests under mixed mode loading and pure mode loading. These tests were carried out in mode II using End Load Split (ELS) tests and in mixed-mode I+II by Mixed Mode Flexure (MMF) tests under static conditions. The test methodology used for the experiments will be presented. The experimental results have been expressed in terms of total strain energy release rate and R-curves. The fracture toughness results show that the T/M interface is more resistant to delamination than the S/M interface.

Triki, E.; Zouari, B.; Jarraya, A.; Dammak, F.

2013-12-01

15

Abaca/polyester nonwoven fabric functionalization for metal ion adsorbent synthesis via electron beam-induced emulsion grafting  

NASA Astrophysics Data System (ADS)

A metal ion adsorbent was developed from a nonwoven fabric trunk material composed of both natural and synthetic polymers. A pre-irradiation technique was used for emulsion grafting of glycidyl methacrylate (GMA) onto an electron beam irradiated abaca/polyester nonwoven fabric (APNWF). The dependence of degree of grafting (Dg), calculated from the weight of APNWF before and after grafting, on absorbed dose, reaction time and monomer concentration were evaluated. After 50 kGy irradiation with 2 MeV electron beam and subsequent 3 h reaction with an emulsion consisting of 5% GMA and 0.5% polyoxyethylene sorbitan monolaurate (Tween 20) surfactant in deionized water at 40 °C, a grafted APNWF with a Dg greater than 150% was obtained. The GMA-grafted APNWF was further modified by reaction with ethylenediamine (EDA) in isopropyl alcohol at 60 °C to introduce amine functional groups. After a 3 h reaction with 50% EDA, an amine group density of 2.7 mmole/gram adsorbent was achieved based from elemental analysis. Batch adsorption experiments were performed using Cu2+ and Ni2+ ions in aqueous solutions with initial pH of 5 at 30 °C. Results show that the adsorption capacity of the grafted adsorbent for Cu2+ is four times higher than Ni2+ ions.

Madrid, Jordan F.; Ueki, Yuji; Seko, Noriaki

2013-09-01

16

Hydrophilic modification of polyester fabric by applying nanocrystalline cellulose containing surface finish.  

PubMed

In this study, polyethylene terephthalate (PET) fabric was modified by applying a hydrophilic surface finishing agent that contains nanocrystalline cellulose (NCC). To impart superior hydrophilicity, NCC was further cationically modified through quaternization by grafting glycidyl tri-methyl ammonium chloride (GTMAC). A textile binder, PrintRite595(®), was added to the finishing system. The surface finish was applied on the fabric using a rolling-drying-curing process. The modified fabric was characterized in terms of coating durability, moisture regain, and wettability. The durability of the surface finish was tested by six repeated washing steps. The surface properties of the fabric changed from hydrophobic to hydrophilic after heat treatment with the NCC-containing surface finishing agent. The results from the washing fastness, SEM, FTIR, and EDX analyses confirmed that the cationic NCC-containing textile surface finish showed superior adhesion onto the cationic dyeable (anionic) PET surface over the un-modified NCC. Furthermore, the cationic textile surface finish was capable of withstanding multiple washing cycles. PMID:23121945

Zaman, Masuduz; Liu, Hongbin; Xiao, Huning; Chibante, Felipe; Ni, Yonghao

2013-01-16

17

Some mechanical properties of untreated jute fabric-reinforced polyester composites  

Microsoft Academic Search

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

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

1999-01-01

18

Biomodification of non-woven polyester fabrics by insulin and RGD for use in serum-free cultivation of tissue cells.  

PubMed

In this study, the development of a novel cell support material was purposed as due to the serum-free cultivation of tissue cells. This material was prepared by immobilizing RGD (Arg-Gly-Asp) sequence of cell-adhesion factor, fibronectin, and cell-growth factor, insulin, to the three-dimensional non-woven polyester fabric (briefly NWPF) discs that have been used successfully in our previous cell culture studies. At first these matrices were partially hydrolyzed and then the carboxyl groups were coupled with RGD or insulin in the presence of water-soluble carbodiimide. The effectiveness of immobilization process was checked with SEM, ATR-FTIR spectroscopy and swelling studies. The maximum amount of immobilized insulin was 6.96 micorgcm(-2) and it was obtained at 200 micorgml(-1) initial insulin concentration for 60 min immobilization period. The cell culture studies which were carried out with human skin fibroblasts (HS An1) showed that, percentage of adhesion on RGD modified NWPF discs is higher than that of other surfaces. i.e., unmodified discs, polystyrene Petri dishes and insulin-immobilized discs, in serum-free culture. According to the results of growth studies, highest cell yield was obtained in the case of insulin-modified discs. PMID:12162325

Gümü?derelio?lu, Menem?e; Türko?lu, Hilal

2002-10-01

19

Liquid crystal polyester thermosets  

SciTech Connect

The present invention relates to the field of curable liquid crystal polyester monomers and to thermoset liquid crystalline polyester compositions prepared therefrom. It is an object of this invention to provide curable liquid crystalline polyester materials. Another object of this invention is to provide a process of preparing curable liquid crystal polyester monomers. Yet another object of this invention is to provide liquid crystalline blends of polyester materials. It is a further object of this invention to provide thermoset liquid crystalline polyester compositions. It is a still further object of this invention to provide thermoset liquid crystalline polyester compositions having a high heat resistance. 1 fig.

Benicewicz, B.C.; Hoyt, A.E.

1990-12-31

20

Liquid crystal polyester thermosets  

SciTech Connect

The present invention relates to the field of curable liquid crystal polyester monomers and to thermoset liquid crystalline polyester compositions prepared therefrom. It is an object of this invention to provide curable liquid crystalline polyester materials. Another object of this invention is to provide a process of preparing curable liquid crystal polyester monomers. Yet another object of this invention is to provide liquid crystalline blends of polyester materials. It is a further object of this invention to provide thermoset liquid crystalline polyester compositions. It is a still further object of this invention to provide thermoset liquid crystalline polyester compositions having a high heat resistance. 1 fig.

Benicewicz, B.C.; Hoyt, A.E.

1990-01-01

21

Effect of the Polyester Fibre Content in a Blend with Thermostable Fibres on the Flameproofing Indexes of Manufactured Materials  

Microsoft Academic Search

Thermolysis processes were investigated and the flameproofing indexes of fabrics made from blends of thermostable Nomex and SVM fibres with polyester fibres were determined. It was found that difficultly flammable materials can be fabricated in the Nomex composite with a 20-25% polyester content and in the SVM composite with a 35-40% polyester content.

Yu. V. Strekalova; N. S. Zubkova; N. I. Konstantinova; Z. Yu. Kozinda

2003-01-01

22

Effect of silicone finishes on the burning behavior of polyester  

NASA Astrophysics Data System (ADS)

Polyester fibers are widely used as filling in home applications such as pillows or comforters. Silicone finishes can be used to reduce friction between fibers during processing or as softeners to impart a pleasant down like hand on the fibers. However, it has been reported that these added silicone-based finishes may have a negative effect on the burning behavior of polyester. This research examined the possible mechanisms that can modify the response of polyester fibers when subjected to a flame source. In this study, a spunbond needled polyester nonwoven substrate was treated with different commercial silicone-based finishes. A vertical flame test was used to compare the effect of silicone finishes on the burning behavior of polyester to the inherent burning behavior of untreated polyester. Thermogravimetric analyses (TGA) were performed on spunbond polyester fabric samples to investigate the influence of silicone finishes on the thermal degradation of polyester in air. Residues from TGA were examined using Scanning Electron Microscopy coupled with elemental analysis. Vertical flammability testing showed that even at a low level, the application of silicone-based finishes on a polyester substrate resulted in a dramatic increase of the flame propagation by preventing its inherent response to heat. Thermograms suggested that the silicone finishes had little or no effect on the thermal degradation of polyester substrates.

Boyon, Julien Xavier Eric

23

Development of high-performance all-polyester sound-absorbing materials  

Microsoft Academic Search

This paper describes two kinds of newly developed polyester sound-absorbing materials. One mainly consists of modified cross-section polyester fabric, and the other consists of recycled polyester fabric. They provide noticeably higher sound-absorbing performance than traditional materials like shoddy or urethane foam. This is because the new materials have greater surface area than that of traditional materials at an identical weight.

Kyoichi Watanabe; Yoshiaki Minemura; Kouichi Nemoto; Hiroshi Sugawara

1999-01-01

24

Analog and digital circuits using organic thin-film transistors on polyester substrates  

Microsoft Academic Search

We have fabricated and characterized analog and digital circuits using organic thin-film transistors on polyester film substrates. These are the first reported dynamic results for organic circuits fabricated on polyester substrates. The high-performance pentacene transistors yield circuits with the highest reported clock frequencies for organic circuits

M. G. Kane; J. Campi; M. S. Hammond; F. P. Cuomo; B. Greening; C. D. Sheraw; J. A. Nichols; D. J. Gundlach; J. R. Huang; C. C. Kuo; L. Jia; H. Klauk; T. N. Jackson

2000-01-01

25

Microwave processing of polyester and polyester-glass composites  

SciTech Connect

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.

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

1992-04-27

26

Polyesters by Photochemical Cyclopolymerization  

NASA Technical Reports Server (NTRS)

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.

Meador, Michael A. (Inventor)

2002-01-01

27

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

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-link density of the polyester network. Various types of poly(diol citrate) scaffolds were fabricated

Ottino, Julio M.

28

Thermal annealing treatment to achieve switchable and reversible oleophobicity on fabrics  

E-print Network

-coating and thermal annealing procedure to tune the liquid wettability of commercially available polyester fabrics with the inherent re-entrant texture of the polyester fabric result in reversibly switchable oleophobicity between of the measured values of the apparent contact angle (* ) for the dip-coated polyester fabrics. KEYWORDS ­ Dip

29

Microfabricated polyester conical microwells for cell culture applications†  

PubMed Central

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

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

2012-01-01

30

21 CFR 177.1590 - Polyester elastomers.  

Code of Federal Regulations, 2011 CFR

...3 2011-04-01 2011-04-01 false Polyester elastomers. 177.1590 Section 177.1590...Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester elastomers identified in paragraph...

2011-04-01

31

40 CFR 721.9507 - Polyester silane.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Polyester silane. 721.9507 Section 721...Chemical Substances § 721.9507 Polyester silane. (a) Chemical substance...The chemical substance identified as a polyester silane (P-95-1022) is...

2013-07-01

32

21 CFR 177.1590 - Polyester elastomers.  

Code of Federal Regulations, 2014 CFR

...3 2014-04-01 2014-04-01 false Polyester elastomers. 177.1590 Section 177.1590...Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester elastomers identified in paragraph...

2014-04-01

33

40 CFR 721.9507 - Polyester silane.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Polyester silane. 721.9507 Section 721...Chemical Substances § 721.9507 Polyester silane. (a) Chemical substance...The chemical substance identified as a polyester silane (P-95-1022) is...

2012-07-01

34

40 CFR 721.9507 - Polyester silane.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Polyester silane. 721.9507 Section 721...Chemical Substances § 721.9507 Polyester silane. (a) Chemical substance...The chemical substance identified as a polyester silane (P-95-1022) is...

2010-07-01

35

40 CFR 721.9507 - Polyester silane.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Polyester silane. 721.9507 Section 721...Chemical Substances § 721.9507 Polyester silane. (a) Chemical substance...The chemical substance identified as a polyester silane (P-95-1022) is...

2011-07-01

36

21 CFR 177.1590 - Polyester elastomers.  

Code of Federal Regulations, 2012 CFR

...3 2012-04-01 2012-04-01 false Polyester elastomers. 177.1590 Section 177.1590...Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester elastomers identified in paragraph...

2012-04-01

37

21 CFR 177.1590 - Polyester elastomers.  

Code of Federal Regulations, 2013 CFR

...3 2013-04-01 2013-04-01 false Polyester elastomers. 177.1590 Section 177.1590...Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester elastomers identified in paragraph...

2013-04-01

38

40 CFR 721.9507 - Polyester silane.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Polyester silane. 721.9507 Section 721...Chemical Substances § 721.9507 Polyester silane. (a) Chemical substance...The chemical substance identified as a polyester silane (P-95-1022) is...

2014-07-01

39

Polyesters from microorganisms.  

PubMed

Bacterial polyesters have been found to have useful properties for applications as thermoplastics, elastomers, and adhesives and are biodegradable and biocompatible. Poly(3-hydroxyalkanoates) (PHAs) and poly(beta-malate) are the most representative polyesters synthesized by microorganisms. PHAs containing a wide variety of repeating units can be produced by bacteria, including those containing many types of pendant functional groups which can be synthesized by microorganisms that are grown on unnatural organic substrates. Poly(beta-malate) is of interest primarily for medical applications, especially for drug delivery systems. In this chapter, the bacterial production and properties of poly(3-hydroxyalkanoates) and poly(beta-malate) are described with emphasis on the former. PMID:11217417

Kim, Y B; Lenz, R W

2001-01-01

40

Polyesters in Higher Plants  

Microsoft Academic Search

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

Pappachan E. Kolattukudy

41

Stabilized unsaturated polyesters  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

42

Liquid crystal polyester thermosets  

DOEpatents

The present invention provides (1) curable liquid crystalline polyester monomers represented by the formula: R.sup.1 --A.sup.1 --B.sup.1 --A.sup.2 --B.sup.2 --A.sup.3 --R.sup.2 where R.sup.1 and R.sup.2 are radicals selected from the group consisting of maleimide, substituted maleimide, nadimide, substituted naimide, ethynyl, and (C(R.sup.3).sub.2).sub.2 where R.sup.3 is hydrogen with the proviso that the two carbon atoms of (C(R.sup.3).sub.2).sub.2 are bound on the aromatic ring of A.sup.1 or A.sup.3 to adjacent carbon atoms, A.sup.1 and A.sup.3 are 1,4-phenylene and the same where said group contains one or more substituents selected from the group consisting of halo, e.g., fluoro, chloro, bromo, or iodo, nitro lower alkyl, e.g., methyl, ethyl, or propyl, alkoxy, e.g., methoxy, ethoxy, or propoxy, and fluoroalkyl, e.g., trifluoromethyl, pentafluoroethyl and the like, A.sup.2 is selected from the group consisting of 1,4-phenylene, 4,4'-biphenyl, 2,6-naphthylene and the same where said groups contain one or more substituents selected from the group consisting of halo, e.g., fluoro, chloro, bromo, or iodo, nitro, lower alkyl, e.g., methyl, ethyl, and propyl, lower alkoxy, e.g., methoxy, ethoxy, or propoxy, and fluoroalkyl or fluoroalkoxy, e.g., trifluoromethyl, pentafluoroethyl and the like, and B.sup.1 and B.sup.2 are selected from the group consisting of --C(O)--O-- and --O--C(O)--, (2) thermoset liquid crystalline polyester compositions comprised of heat-cured segments derived from monomers represented by the formula: R.sup.1 --A.sup.1 --B.sup.1 --A.sup.2 --B.sup.2 --A.sup.3 --R.sup.2 as described above, (3) curable blends of at least two of the polyester monomers and (4) processes of preparing the curable liquid crystalline polyester monomers.

Benicewicz, Brian C. (Los Alamos, NM); Hoyt, Andrea E. (Los Alamos, NM)

1992-01-01

43

Future of microbial polyesters.  

PubMed

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

Lee, Gi Na; Na, Jonguk

2013-01-01

44

Pressure polymerization of polyester  

DOEpatents

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.

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

45

Polyester fiber: from its invention to its present position.  

PubMed

The use of polyester fibers has grown more rapidly than that of any other man-made fiber. Many factors have contributed to this growth. Polyester's unique physical properties of strength, high modulus, elasticity, and durability are the basis for its success. The tailorability of the fiber makes it possible to generate a whole family of property variants for a wide variety of end uses. The ready availability and low cost of the raw materials, the continuing advances in polymerization technology, and the versatility of the melt spinning process have also been major factors in establishing polyester as the leading man-made fiber. New end uses have had a major impact on the growth of polyester. Most notable was the introduction of durable press fabrics for clothing and home furnishings. The consumer preference for easy-care fabrics and garments makes the durable press area one of continuing growth. Two relatively new areas where growth is expected to continue at a rapid rate are tire cord and textured knits for women's and men's outerwear. PMID:17809208

Brown, A E; Reinhart, K A

1971-07-23

46

Polyester based hybrid organic coatings  

NASA Astrophysics Data System (ADS)

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.

Wang, Xiaojiang

47

Fabric  

NSDL National Science Digital Library

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.

N/A N/A (None; )

2004-07-12

48

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

NASA Technical Reports Server (NTRS)

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.

Cuddihy, E. F.

1972-01-01

49

Fabric Facts.  

E-print Network

result in fabric changes. The following charts are designed as convenient references in selecting and maintaining fab rics and garments. Labels will aid you in identifying fibers and finishes. Trade names for fibers and finishes are followed... by the general name-for example, Dacron polyester. Trade names also may indicate a certain type of yarn processing. Several fibers or finishes may be combined under one trade name. Refer to Extension publication B-1240 Guidelines tor Quality Clothing...

Saunders, Becky

1980-01-01

50

Multifunctional aliphatic polyester nanofibers for tissue engineering  

PubMed Central

Electrospun fibers based on aliphatic polyesters, such as poly(?-caprolactone) (PCL), have been widely used in regenerative medicine and drug delivery applications due to their biocompatibility, low cost and ease of fabrication. However, these aliphatic polyester fibers are hydrophobic in nature, resulting in poor wettability, and they lack functional groups for decorating the scaffold with chemical and biological cues. Current strategies employed to overcome these challenges include coating and blending the fibers with bioactive components or chemically modifying the fibers with plasma treatment and reactants. In the present study, we report on designing multifunctional electrospun nanofibers based on the inclusion complex of PCL-?-cyclodextrin (PCL-?-CD), which provides both structural support and multiple functionalities for further conjugation of bioactive components. This strategy is independent of any chemical modification of the PCL main chain, and electrospinning of PCL-?-CD is as easy as electrospinning PCL. Here, we describe synthesis of the PCL-?-CD electrospun nanofibers, elucidate composition and structure, and demonstrate the utility of functional groups on the fibers by conjugating a fluorescent small molecule and a polymeric-nanobead to the nanofibers. Furthermore, we demonstrate the application of PCL-?-CD nanofibers for promoting osteogenic differentiation of human adipose-derived stem cells (hADSCs), which induced a higher level of expression of osteogenic markers and enhanced production of extracellular matrix (ECM) proteins or molecules compared with control PCL fibers. PMID:23507886

Zhan, Jianan; Singh, Anirudha; Zhang, Zhe; Huang, Ling; Elisseeff, Jennifer H.

2012-01-01

51

Polyester projects for India, Pakistan  

SciTech Connect

India's Indo Rama Synthetics (Bombay) is planning a $186-million integrated polyester fiber and filament complex at Nagpur, Maharashtra. The complex will have annual capacities for 38,000 m.t. of polyester chips by polycondensation, 25,000 m.t. of polyester staple fiber, and 12,000 m.t. of polyester blended yarn. The company is negotiating with the main world suppliers of polycondensation technology. The first stage of the project is slated to begin production by the end of this year and be fully completed by 1994. In Pakistan, National Fibers Ltd. (PNF; Karachi) has signed a deal with Zimmer (Frankfurt) for technology, procurement, construction, and support work to expand polyester staple fiber capacity from 14,000 m.t./year to 52,000 m.t./year. The technology involves a continuous polymerization process. The project also calls for improvements to PNF's existing batch plant. It is scheduled for completion by the end of 1994. Total cost of the project is estimated at Rs1.745 billion ($70 million), out of which the foreign exchange component is Rs1.05 billion. The Islamic Development Bank (Jeddah; Saudi Arabia) has already approved a $27-million slice of the financing, while the balance of the foreign exchange loan is being arranged through suppliers credit. Local currency loans will be provided by other financial institutions in Pakistan.

Siddiqi, R.

1993-02-10

52

Numerical Investigations of Polyester Coextrusion Instabilities  

E-print Network

Numerical Investigations of Polyester Coextrusion Instabilities O. Mahdaouia and P. Laureb,a and J polyesters for which Preprint submitted to Journal of Non-Newtonian Fluid Mechanics December 7, 2012 hal polyester patented formulations which present very different rheological properties. For some processing

Paris-Sud XI, Université de

53

Introduction Aliphatic polyesters derived from renewable  

E-print Network

Introduction Aliphatic polyesters derived from renewable resources are of increasing interest of these polyesters are already commercially produced in bacteria under nutrient-limited conditions; however of polyesters by ring-opening polymerization. For example, -valerolactone can be obtained in high yield from low

54

Which polyesters can mimic polyethylene?  

PubMed

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

Stempfle, Florian; Ortmann, Patrick; Mecking, Stefan

2013-01-11

55

Fabrication  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

56

Synthesis of improved polyester resins  

NASA Technical Reports Server (NTRS)

Eighteen aromatic unsaturated polyester prepolymers prepared by a modified interfacial condensation technique were investigated for their solubility in vinyl monomers and ability to provide high char yield forming unsaturated polyester resins. The best resin system contained a polyester prepolymer of phthalic, fumaric and diphenic acids reacted with 2,7-naphthalene diol and 9,9-bis(4-hydroxyphenyl)fluorene. This prepolymer is very soluble in styrene, divinyl benzene, triallyl cyanurate, diallyl isophthalate and methylvinylpyridine. It provided anaerobic char yields as high as 41 percent at 800 C. The combination of good solubility and char yield represents a significant improvement over state-of-the-art unsaturated polyester resins. The majority of the other prepolymers had only low or no solubility in vinyl monomers. Graphite composites from this prepolymer with styrene were investigated. The cause for the observed low shear strengths of the composites was not determined, however 12-week aging of the composites at 82 C showed that essentially no changes in the composites had occurred.

Mcleod, A. H.; Delano, C. B.

1979-01-01

57

Hydrolysis of polyesters by lipases  

Microsoft Academic Search

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

Yutaka Tokiwa; Tomoo Suzuki

1977-01-01

58

Jute-reinforced polyester composites  

Microsoft Academic Search

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

P. J. Roe; M. P. Ansell

1985-01-01

59

40 CFR 721.10436 - Amine neutralized phosphated polyesters (generic).  

Code of Federal Regulations, 2014 CFR

...false Amine neutralized phosphated polyesters (generic). 721.10436 Section...10436 Amine neutralized phosphated polyesters (generic). (a) Chemical substance...generically as amine neutralized phosphated polyesters (PMN P-99-1217 and...

2014-07-01

60

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Polyester polyurethane acrylate. 721.8082...Chemical Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical...chemical substance identified generically as polyester polyurethane acrylate (PMN...

2014-07-01

61

40 CFR 721.10449 - Aromatic polyester polyol (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Aromatic polyester polyol (generic). 721.10449 ...Substances § 721.10449 Aromatic polyester polyol (generic). (a) Chemical...substance identified generically as aromatic polyester polyol (PMN P-02-172) is...

2013-07-01

62

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Polyester polyurethane acrylate. 721.8082...Chemical Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical...chemical substance identified generically as polyester polyurethane acrylate (PMN...

2013-07-01

63

40 CFR 721.10449 - Aromatic polyester polyol (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Aromatic polyester polyol (generic). 721.10449 ...Substances § 721.10449 Aromatic polyester polyol (generic). (a) Chemical...substance identified generically as aromatic polyester polyol (PMN P-02-172) is...

2014-07-01

64

40 CFR 721.10578 - Unsaturated polyester imide (generic).  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Unsaturated polyester imide (generic). 721.10578 Section...Substances § 721.10578 Unsaturated polyester imide (generic). (a) Chemical...identified generically as unsaturated polyester imide (PMN P-10-231) is...

2014-07-01

65

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Polyester polyurethane acrylate. 721.8082...Chemical Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical...chemical substance identified generically as polyester polyurethane acrylate (PMN...

2011-07-01

66

40 CFR 721.10578 - Unsaturated polyester imide (generic).  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Unsaturated polyester imide (generic). 721.10578 Section...Substances § 721.10578 Unsaturated polyester imide (generic). (a) Chemical...identified generically as unsaturated polyester imide (PMN P-10-231) is...

2013-07-01

67

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Polyester polyurethane acrylate. 721.8082...Chemical Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical...chemical substance identified generically as polyester polyurethane acrylate (PMN...

2012-07-01

68

40 CFR 721.10436 - Amine neutralized phosphated polyesters (generic).  

Code of Federal Regulations, 2013 CFR

...false Amine neutralized phosphated polyesters (generic). 721.10436 Section...10436 Amine neutralized phosphated polyesters (generic). (a) Chemical substance...generically as amine neutralized phosphated polyesters (PMN P-99-1217 and...

2013-07-01

69

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721.8082...Chemical Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical...chemical substance identified generically as polyester polyurethane acrylate (PMN...

2010-07-01

70

77 FR 60720 - Certain Polyester Staple Fiber From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...731-TA-1104 (Review)] Certain Polyester Staple Fiber From China Determination On the...antidumping duty order on certain polyester staple fiber from China would be likely to lead...September 2012), entitled Certain Polyester Staple Fiber from China: Investigation...

2012-10-04

71

75 FR 23300 - Greige Polyester/Cotton Printcloth From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2010-05-03

72

40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).  

Code of Federal Regulations, 2011 CFR

...false Polyether polyester copolymer phosphate (generic). 721.10213 Section...10213 Polyether polyester copolymer phosphate (generic). (a) Chemical substance...generically as polyether polyester copolymer phosphate (PMN P-09-253) is subject...

2011-07-01

73

40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).  

Code of Federal Regulations, 2013 CFR

...false Polyether polyester copolymer phosphate (generic). 721.10213 Section...10213 Polyether polyester copolymer phosphate (generic). (a) Chemical substance...generically as polyether polyester copolymer phosphate (PMN P-09-253) is subject...

2013-07-01

74

40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).  

Code of Federal Regulations, 2014 CFR

...false Polyether polyester copolymer phosphate (generic). 721.10213 Section...10213 Polyether polyester copolymer phosphate (generic). (a) Chemical substance...generically as polyether polyester copolymer phosphate (PMN P-09-253) is subject...

2014-07-01

75

40 CFR 721.10213 - Polyether polyester copolymer phosphate (generic).  

Code of Federal Regulations, 2012 CFR

...false Polyether polyester copolymer phosphate (generic). 721.10213 Section...10213 Polyether polyester copolymer phosphate (generic). (a) Chemical substance...generically as polyether polyester copolymer phosphate (PMN P-09-253) is subject...

2012-07-01

76

Straw-reinforced polyester composites  

Microsoft Academic Search

Annual crop fibres are rich in cellulose and they are a cheap and rapidly renewable source of fibres with potential for polymer reinforcement. Straw fibres have been incorporated in a polyester resin matrix and the properties of the fibre and composite determined. The fibres have a Young's modulus of approximately 8 GN m-2 and an effective density of 5.1 kN

N. M. White; M. P. Ansell

1983-01-01

77

Flax fibre–polyester composites  

Microsoft Academic Search

Composites of an aliphatic polyester (Bionolle) with natural flax fibres are prepared by batch mixing. The effect of processing conditions on fibre length distribution and the dependence of the composite mechanical properties on fibre content are investigated. The tensile modulus changes with fibre content according to the modified rule-of-mixture equation, with a fibre orientation efficiency factor ?0=0.194. The strength of

Massimo Baiardo; Elisa Zini; Mariastella Scandola

2004-01-01

78

Biodegradability and Biodegradation of Polyesters  

Microsoft Academic Search

A variety of biodegradable plastics have been developed in order to obtain useful materials that do not cause harm to the\\u000a environment. Among the biodegradable plastics, aliphatic polyesters such as: poly(3-hydroxybutyrate) (PHB), poly(?-caprolactone)\\u000a (PCL), poly(butylene succinate) (PBS), and poly(l-lactide) (PLA) have become the focus of interest because of their inherent biodegradability. However, before their widespread\\u000a applications, comprehensive studies on the

Yutaka Tokiwa; Buenaventurada P. Calabia

2007-01-01

79

TESTS OF FABRIC FILTRATION MATERIALS  

EPA Science Inventory

The report describes laboratory and pilot scale testing of filter fabrics. Tests were made on flat specimens and on bags. Fifteen styles of fabrics (made from cotton, polyester, aramid, or glass) were tested, using cement, coal, or talc dusts. Collection efficiencies and pressure...

80

TEST OF FABRIC FILTRATION MATERIALS  

EPA Science Inventory

The report describes pilot scale and laboratory tests of U.S. and Polish woven baghouse fabrics. Cotton, polyester, aramid, and glass fabrics were tested using cement, flyash, coal, and talc dusts at loadings of about 10 g/cu m, filtration velocities of 60 and 80 cu m/sq m, and a...

81

Biomaterials 26 (2005) 57275736 Surface modification of biodegradable polyesters with fatty acid  

E-print Network

method for incorporating target ligands into the surface of biocompatible polyester poly(lactic-co-glycolic; Drug delivery; Microsphere; Scaffold 1. Introduction Biodegradable polymers fabricated from poly(lactic- co-glycolic acid) (PLGA) have emerged as powerful potential carriers for small and large molecules

Fahmy, Tarek

2005-01-01

82

Improved Flame Resistance of Cotton/Polyester Fleece with Phosphorous-Based Polycarboxylic Acids  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phosphorus-based polycarboxylic acid formulations containing sodium phosphinicosuccinic acid or sodium phosphinicobissuccinic acid were used to esterify 80/20 cotton-polyester fleece fabric. These acids are readily prepared as described in the literature by reaction of maleic acid with sodium hypoph...

83

Aliphatic Polyesters and Cellulose-Based Polymers for Controlled Release Applications  

Microsoft Academic Search

The general technologies for fabricating drug delivery systems are briefly discussed in the present review. Furthermore, two types of commonly used polymers, biodegradable aliphatic polyesters for parenteral administration and cellulose-based polymers for oral uses, are presented by means of selected examples of their properties and applications to control drug release.

Rong-Kun Chang; James C. Price

1988-01-01

84

Bioresorbability and biocompatibility of aliphatic polyesters  

Microsoft Academic Search

The field of biodegradable polymers is a fast growing area of polymer science because of the interest of such compounds for temporary surgical and pharmacological applications. Aliphatic polyesters constitute the most attractive family among which poly(a-hydroxy acids) have been extensively studied. In the past two decades, several excellent reviews have been published to present the general properties of aliphatic polyesters.

M. Vert; S. M. Li; G. Spenlehauer; P. Guerin

1992-01-01

85

Biodegradation of polyesters containing aromatic constituents  

Microsoft Academic Search

Polymers, which undergo a controlled biological degradation by micro-organisms came to remarkable interest during the last years. Composting for instance could so be established as an alternative waste management system for parts of the plastic waste. Within this group of innovative polymer, polyesters play a predominant role, due to their potentially hydrolyzable ester bonds. While aromatic polyesters such as poly(ethylene

Rolf-Joachim Müller; Ilona Kleeberg; Wolf-Dieter Deckwer

2001-01-01

86

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...

87

Flame retardant antibacterial cotton high-loft nonwoven fabrics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Flame retardant treated gray cotton fibers were blended with antibacterial treated gray cotton fibers and polyester/polyester sheath/core bicomponent fibers to form high-loft fabrics. The high flame retardancy (FR) and antibacterial property of these high lofts were evaluated by limiting oxygen inde...

88

Bio-Based Bisfuran: Synthesis, Crystal Structure and Low Molecular Weight Amorphous Polyester.  

PubMed

Discovery of renewable monomer feedstocks for fabrication of polymeric demand is critical in achieving sustainable materials. In the present work we have synthesized bisfuran diol (BFD) monomer from furfural, over four steps. BFD was examined via X-ray crystallography to understand the molecular arrangement in space, hydrogen bonding and packing of the molecules. This data was further used to compare BFD with structurally related Bisphenol A (BPA), and its known derivatives to predict the potential estrogenic or anti-estrogenic activities in BFD. Further, BFD was reacted with succinic acid to generate polyester material, bisfuran polyester (BFPE-1). MALDI characterization of BFPE-1 indicates low molecular weight polyester and thermal analysis reveals amorphous nature of the material. PMID:25045189

Gaitonde, Vishwanath; Lee, Kyunghee; Kirschbaum, Kristin; Sucheck, Steven J

2014-07-23

89

SectionILesson2FabricSelection Master Clothing Volunteer Program  

E-print Network

. Fabrics are made of different fibers and require different care. Read the bolt of fabric for fiber content (e.g. 100% cotton, 50% cotton/50%polyester, etc.), preshrunk, colorfast (retains color for the normal

90

Expandable Foam from Amorphous Polyester Resin  

Microsoft Academic Search

A resilient foam that is both expandable and moldable was prepared from an amorphous polyester resin using a mixed blowing agent of a high-solubility compound and a low-permeability compound. The high-solubility compound permits a high degree of expansion, while the low-permeability compound renders secondary expandability. The polyester foam remedies the deficiencies of existing bead products. Polystyrene beads retain blowing agents

Chung P. Park; Gerald A. Garcia; Roby G. Watson

2003-01-01

91

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS, BWF AMERICA, INC., GRADE 700 MPS POLYESTER FELT FILTER SAMPLE  

EPA Science Inventory

EPA's National Risk Management Research Laboratory, through its Environmental Technology Verification Program, evaluated the performance of a bag house filtration product for use controlling PM2.5. The product was BWF America, Inc., filter fabric Grade 700 Polyester Felt. All tes...

92

One-pot preparation of unsaturated polyester nanocomposites containing functionalized graphene sheets via a novel solvent-exchange method  

Technology Transfer Automated Retrieval System (TEKTRAN)

This paper reports a convenient one-pot method integrating a novel solvent-exchange method into in situ melt polycondensation to fabricate unsaturated polyester nanocomposites containing functionalized graphene sheets (FGS). A novel solvent-exchange method was first developed to prepare graphene oxi...

93

Effectiveness of various UV-absorbers on the dyeing of polyester with disperse dyes. Part IV  

Microsoft Academic Search

The effect of benzotriazole type UV-absorbers Tinuvin P and Tinuvin 327 and 2,4-dihydroxy benzophenone in the dyeing of polyester fabrics with C.I. Disperse Yellow 86 and C.I. Disperse Red 86 at various depths of dyeing was studied. Various amounts and two application processes of the UV-absorber were used. The dye and UV-absorber uptake, and the light and sublimation fastness of

E. G. Tsatsaroni; A. H. Kehayoglou; I. C. Eleftheriadis; L. E. Kyriazis

1998-01-01

94

Effectiveness of various UV-absorbers in dyeing of polyester with disperse dyes. Part III  

Microsoft Academic Search

The effect of various amounts of two benzotriazole (Tinuvin P and Tinuvin 327) and one benzophenone (2,4-dihydroxybenzophenone) type UV-absorbers in the dyeing of polyester fabrics with commercial samples of a red monoazo disperse dye and Viosperse Yellow GLFS was examined at various depths of dyeing (0.5, 1.75 and 3% o.w.f.). The UV-absorbers were applied to the fibre at various UV-absorber\\/dye

A. H Kehayoglou; E. G Tsatsaroni; I. C Eleftheriadis; K. C Loufakis; L. E Kyriazis

1997-01-01

95

Hygrothermomechanical evaluation of transverse filament tape epoxy/polyester fiberglass composites  

NASA Technical Reports Server (NTRS)

Transverse filament tape (TFT) fiberglass/epoxy and TFT polyester composites intended for low cost wind turbine blade fabrication have been subjected to static and cyclic load behavior tests whose results are presently evaluated on the basis of an integrated hygrothermomechanical response theory. Laminate testing employed simulated filament winding procedures. 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 R-ratio values.

Lark, R. F.; Chamis, C. C.

1984-01-01

96

75 FR 42784 - Greige Polyester/Cotton Printcloth From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2010-07-22

97

Microbial production of lactate-containing polyesters  

PubMed Central

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

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

2013-01-01

98

Polyaniline coated conducting fabrics. Chemical and electrochemical characterization  

Microsoft Academic Search

Polyaniline coated conducting fabrics have been obtained by chemical oxidation of aniline by potassium peroxydisulfate on polyester fabrics. Two different acids have been employed to carry out the synthesis (HCl and H2SO4), obtaining the best results of conductivity with the latter one. The conducting fabrics have been characterized chemically by means of Fourier transform infrared spectroscopy with attenuated total reflection

J. Molina; M. F. Esteves; J. Fernández; J. Bonastre; F. Cases

2011-01-01

99

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

Microsoft Academic Search

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.,

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

2010-01-01

100

Polyester Polyols: Synthesis and Characterization of Diethylene Glycol Terephthalate Oligomers  

E-print Network

Polyester Polyols: Synthesis and Characterization of Diethylene Glycol Terephthalate Oligomers OLEG 17 January 2003 ABSTRACT: The composition of polyester polyols derived from terephthalic acid (TPA INTRODUCTION Polyester polyols1,2 based on aliphatic and aromatic dicarboxylic acids are valuable materials

Kaszynski, Piotr

101

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Hydroxy terminated polyester. 721.6485 Section 721.6485...Substances § 721.6485 Hydroxy terminated polyester. (a) Chemical substance and significant...identified generically as a hydroxy terminated polyester (PMN P-95-1213) is subject...

2011-07-01

102

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Hydroxy terminated polyester. 721.6485 Section 721.6485...Substances § 721.6485 Hydroxy terminated polyester. (a) Chemical substance and significant...identified generically as a hydroxy terminated polyester (PMN P-95-1213) is subject...

2010-07-01

103

49 CFR 173.165 - Polyester resin kits.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Polyester resin kits. 173.165 Section 173.165...Other Than Class 1 and Class 7 § 173.165 Polyester resin kits. (a) Polyester resin kits consisting of a base material...

2013-10-01

104

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Hydroxy terminated polyester. 721.6485 Section 721.6485...Substances § 721.6485 Hydroxy terminated polyester. (a) Chemical substance and significant...identified generically as a hydroxy terminated polyester (PMN P-95-1213) is subject...

2012-07-01

105

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Hydroxy terminated polyester. 721.6485 Section 721.6485...Substances § 721.6485 Hydroxy terminated polyester. (a) Chemical substance and significant...identified generically as a hydroxy terminated polyester (PMN P-95-1213) is subject...

2013-07-01

106

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Hydroxy terminated polyester. 721.6485 Section 721.6485...Substances § 721.6485 Hydroxy terminated polyester. (a) Chemical substance and significant...identified generically as a hydroxy terminated polyester (PMN P-95-1213) is subject...

2014-07-01

107

49 CFR 173.165 - Polyester resin kits.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Polyester resin kits. 173.165 Section...Class 1 and Class 7 § 173.165 Polyester resin kits. (a) Except for transportation by aircraft, polyester resin kits consisting of a base...

2012-10-01

108

49 CFR 173.165 - Polyester resin kits.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Polyester resin kits. 173.165 Section...Class 1 and Class 7 § 173.165 Polyester resin kits. (a) Except for transportation by aircraft, polyester resin kits consisting of a base...

2011-10-01

109

49 CFR 173.165 - Polyester resin kits.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Polyester resin kits. 173.165 Section 173.165...Other Than Class 1 and Class 7 § 173.165 Polyester resin kits. (a) Polyester resin kits consisting of a base material...

2014-10-01

110

Engineering bacteria to manufacture functionalized polyester beads  

PubMed Central

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

Draper, Jenny L.; Rehm, Bernd H.

2012-01-01

111

Polyether/Polyester Graft Copolymers  

NASA Technical Reports Server (NTRS)

Higher solvent resistance achieved along with lower melting temperature. New technique provides method of preparing copolymers with polypivalolactone segments grafted onto poly (2,6-dimethyl-phenylene oxide) backbone. Process makes strong materials with improved solvent resistance and crystalline, thermally-reversible crosslinks. Resulting graft copolymers easier to fabricate into useful articles, including thin films, sheets, fibers, foams, laminates, and moldings.

Bell, Vernon L., Jr.; Wakelyn, N.; Stoakley, D. M.; Proctor, K. M.

1986-01-01

112

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...

113

Correlation spectroscopy applied to glycerol polyester spectra  

Technology Transfer Automated Retrieval System (TEKTRAN)

The recent development of glycerol polyesters for use as controlled release matrix materials in the nutraceuticals and pharmaceuticals industries presented a unique opportunity to apply correlation spectroscopy. In a typical formulation the glycerol is reacted with a polyfunctional acid such as citr...

114

An experimental investigation of nonwoven filter cloth with and without reinforcement of woven fabric  

Microsoft Academic Search

In this experimental study, the effect of needling intensity and reinforcement fabric on some physical properties of needle?punched nonwoven filters was investigated. The needle?punched nonwoven filters with different needling intensities were fabricated with and without reinforcement fabrics. Recycled polyester fibers were chosen as raw materials, and acrylic fibers were used in the reinforcement fabrics. The variation of physical properties of

M. E. Yuksekkaya; M. Tercan; G. Dogan

2010-01-01

115

Atmospheric-air plasma enhances coating of different lubricating agents on polyester fiber  

NASA Astrophysics Data System (ADS)

This research work involves the plasma treatment of polyethylene terephthalate fiber to improve performance of various ionic lubricating agents. To do this, polyester fabric was pre-scoured with detergent, treated with atmospheric-air plasma and then coated with anionic, cationic and nonionic emulsions. Chemical and physical properties of samples were investigated by the use of Fourier transform infrared spectroscopy (FTIR), bending lengths (BL), wrinkle recovery angles (WRA), fiber friction coefficient analysis (FFCA), moisture absorbency (MA), scanning electron microscopy (SEM) and reflectance spectroscopy (RS). Study on chemical properties of fibers revealed that the plasma pretreatment modifies the surface of fibers and increases the reactivity of substrate toward various ionic emulsions. Physical properties of textiles indicated that the combination of plasma and emulsion treatments on polyester can improve crease resistant, drapeability and water repellency due to uniform coating of various emulsions on surface of textiles.

Ebrahimi, I.; Kiumarsi, A.; Parvinzadeh Gashti, M.; Rashidian, R.; Norouzi, M. Hossein

2011-10-01

116

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

NASA Astrophysics Data System (ADS)

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.

Poillucci, Richard

117

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2010 CFR

...true Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2010-04-01

118

40 CFR 721.10298 - MDI terminated polyester polyurethane polymer (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false MDI terminated polyester polyurethane polymer (generic). ...Substances § 721.10298 MDI terminated polyester polyurethane polymer (generic). ...identified generically as MDI terminated polyester polyurethane polymer...

2014-07-01

119

40 CFR 721.10298 - MDI terminated polyester polyurethane polymer (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false MDI terminated polyester polyurethane polymer (generic). ...Substances § 721.10298 MDI terminated polyester polyurethane polymer (generic). ...identified generically as MDI terminated polyester polyurethane polymer...

2013-07-01

120

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2012 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2012-04-01

121

40 CFR 721.10298 - MDI terminated polyester polyurethane polymer (generic).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false MDI terminated polyester polyurethane polymer (generic). ...Substances § 721.10298 MDI terminated polyester polyurethane polymer (generic). ...identified generically as MDI terminated polyester polyurethane polymer...

2012-07-01

122

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2014 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2014-04-01

123

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

E-print Network

Characterization of Polyester Properties by Molecular Simulations Techniques Caibao Qian, Tahir of the polyesters: polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene isophthalate group, and the rigidity of chains on the properties of the polyesters both in crystalline and amorphous

Goddard III, William A.

124

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2013 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2013-04-01

125

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2011 CFR

...false Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260...260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section...

2011-04-01

126

78 FR 17637 - Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty Administrative Review...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Polyester Staple Fiber From Taiwan: Preliminary Results...the antidumping duty order on polyester staple fiber (PSF) from Taiwan. The period...Duty Administrative Review: Polyester Staple Fiber from Taiwan'' dated...

2013-03-22

127

75 FR 64694 - Second Antidumping Duty Administrative Review of Certain Polyester Staple Fiber From the People's...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administrative Review of Certain Polyester Staple Fiber From the People's Republic of...administrative review of certain polyester staple fiber (``PSF'') from the People's...2008-May 31, 2009. Certain Polyester Staple Fiber From the People's Republic...

2010-10-20

128

78 FR 51707 - Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-839] Certain Polyester Staple Fiber From the Republic of Korea: Rescission of...the antidumping duty order on certain polyester staple fiber (polyester staple fiber) from the Republic of Korea (Korea)...

2013-08-21

129

76 FR 58040 - Certain Polyester Staple Fiber From Korea and Taiwan  

Federal Register 2010, 2011, 2012, 2013, 2014

...826; Second Review] Certain Polyester Staple Fiber From Korea and Taiwan Determination...antidumping duty orders on certain polyester staple fiber from Korea and Taiwan would be likely...September 2011), entitled Certain Polyester Staple Fiber From Korea and Taiwan:...

2011-09-19

130

78 FR 38938 - Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review; 2011...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Polyester Staple Fiber From Taiwan: Final Results of Antidumping...the antidumping duty order on polyester staple fiber (PSF) from Taiwan. The period...1\\ See Polyester Staple Fiber From Taiwan: Preliminary...

2013-06-28

131

High performance polyester concrete using recycled PET  

SciTech Connect

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.

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

1995-10-01

132

Polyimide nanofoams from aliphatic polyester based copolymers  

SciTech Connect

High temperature polymer foams were prepared using microphase separated block copolymers where the major component is thermally stable block and the minor component is thermally labile. Upon thermal treatment, the dispersed minor component undergoes thermolysis leaving pores the size and shape of which are dictated by the initial copolymer morphology. The driving force behind the survey of aliphatic polyesters as possible labile blocks stems from their quantitative degradation into low boiling, polar degradation products via a backbiting process. Block copolymers were prepared using either a monofunctional caprolactone or a valerolactone oligomer and a high T. polyimide. Microphase morphologies were observed in each case. Thermal decomposition of the polyester blocks was accomplished by a thermal treatment at 370{degrees}C for 5 h. Significant density reductions were measured, and the resulting foams showed pore sizes in the 60-70 {Angstrom} range.

Hedrick, J.L.; Carter, K.R.; Richter, R.; Russell, T.P. [Almaden Research Center, San Jose, CA (United States)] [and others

1996-10-01

133

Thermomechanical behavior of liquid-crystal polyesters  

Microsoft Academic Search

We have used the thermomechanical method to investigate the processes of self-elongation and shrinkage in uniaxially oriented liquid-crystal (LC) polyesters (CPET — the copolyester of terephthalic acid, phenylhydroquinone, and p-hydroxybenzoic acid; Ultrax — the copolyester of terephthalic acid, isophthalic acid, and bisphenol) and the injection-molded copolyester of hydroxybenzoic and hydroxynaphthoic acids Vectra A900. A universal tensile tester and a thermomechanical

S. E. Kudryavtseva

1996-01-01

134

Synthesis and Characterization of Unsaturated Thermotropic Polyesters Prepared via Acyclic Diene Metathesis Polymerization  

E-print Network

Synthesis and Characterization of Unsaturated Thermotropic Polyesters Prepared via Acyclic Diene. In the area of main chain LC polyesters, several approaches toward spacer incorporation have been adopted

Mather, Patrick T.

135

Polyether-polyester graft copolymer  

NASA Technical Reports Server (NTRS)

Described is a polyether graft polymer having improved solvent resistance and crystalline thermally reversible crosslinks. The copolymer is prepared by a novel process of anionic copolymerization. These polymers exhibit good solvent resistance and are well suited for aircraft parts. Previous aromatic polyethers, also known as polyphenylene oxides, have certain deficiencies which detract from their usefulness. These commercial polymers are often soluble in common solvents including the halocarbon and aromatic hydrocarbon types of paint thinners and removers. This limitation prevents the use of these polyethers in structural articles requiring frequent painting. In addition, the most popular commercially available polyether is a very high melting plastic. This makes it considerably more difficult to fabricate finished parts from this material. These problems are solved by providing an aromatic polyether graft copolymer with improved solvent resistance and crystalline thermally reversible crosslinks. The graft copolymer is formed by converting the carboxyl groups of a carboxylated polyphenylene oxide polymer to ionic carbonyl groups in a suitable solvent, reacting pivalolactone with the dissolved polymer, and adding acid to the solution to produce the graft copolymer.

Bell, Vernon L. (inventor)

1987-01-01

136

Degradation rates of glycerol polyesters at acidic and basic conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Polyesters prepared from glycerol with mixtures of adipic and citric acids were evaluated in the laboratory to estimate degradation rates over a range of pH conditions. These renewable polymers provide a market for glycerol that is generated during biodiesel production. The polyesters were prepared...

137

Protein engineering towards biotechnological production of bifunctional polyester beads.  

PubMed

Microbial polyester inclusions have previously been demonstrated to be applicable as versatile beads outside the bacterial cell. Engineering of proteins selectively binding to the polyester inclusions was conceived to produce polyester beads simultaneously displaying two protein-based functions suitable for applications in, for example, fluorescence activated cell sorting (FACS). The polyester synthase and the phasin protein were fused to the green fluorescent protein (GFP) and the murine myelin oligodendrocyte glycoprotein (MOG), respectively, or GFP and MOG were fused to the N- and C-terminus, respectively, of only the phasin. In both cases, fusion proteins were found to be attached to isolated polyester inclusions while displaying both functionalities per bead. Functionalities at the bead surface were assessed by ELISA, FACS and fluorescence microscopy. The respective double fusion protein was identified by peptide fingerprinting using MALDI-TOF/MS. PMID:18800192

Atwood, Jane A; Rehm, Bernd H A

2009-01-01

138

Reactive modification of polyesters and their blends  

NASA Astrophysics Data System (ADS)

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.

Wan, Chen

2004-12-01

139

Hydrolysis of polyesters by serine proteases  

Microsoft Academic Search

The substrate specificity of a-chymotrypsin and other serine proteases, trypsin, elastase, proteinase K and subtilisin, towards hydrolysis of various polyesters was examined using poly(L-lactide) (PLA), poly(ß-hydroxybutyrate) (PHB), poly(ethylene succinate) (PES), poly(ethylene adipate) (PEA), poly(butylene succinate) (PBS), poly(butylene succinate-co-adipate) (PBS\\/A), poly[oligo(tetramethylene succinate)-co-(tetramethylane carbonate)] (PBS\\/C), and poly(?-caprolactone) (PCL). a-Chymotrypsin could degrade PLA and PEA with a lower activity on PBS\\/A. Proteinase K

Hyun-A Lim; Takao Raku; Yutaka Tokiwa

2005-01-01

140

Superfiber For Strong, Light Fabrics  

NASA Technical Reports Server (NTRS)

New ultrahigh-molecular-weight fiber offers major advantages as fabric for space suits, diving suits, sporting goods, sails, and ultralight aircraft. Polyolefin fiber has extremely high modulus of elasticity, low elongation, high specific strength, low specific gravity, resistance to chemicals, low moisture absorption, and high resistance to damage by flexure and abrasion. Consists of elongated, highly aligned, highly crystalline polyethylene molecules. Structure not only results in high strength-to-weight ratio but also gives high resistance to tearing and ripping. Fibers woven in many patterns. Offers combination of desirable properties not found in nylon, polyester, or aramid fabrics.

Dawn, Frederic S.; Kosmo, Joseph J.

1991-01-01

141

Hydrolytic kinetics of biodegradable polyester monolayers  

SciTech Connect

The rate of hydrolysis of Langmuir monolayer films of a series of biodegradable polyesters was investigated at the air/water interface. The present study investigated parameters such as degradation medium, pH, and time. The hydrolysis of polyester monolayers strongly depended on both the degradation medium used to control subphase pH and the concentration of active ions. Under the conditions studied here, polymer monolayers showed faster hydrolysis when they were exposed to a basic subphase rather than that of acidic or neutral subphase. The basic (pH = 10) hydrolysis of [poly(l-lactide)/polycaprolactone](l-PLA/PCL 1/1 by mole) blend was faster than that of each homopolymer at the initial stage. This result is explained by increasing numbers of base attack sites per unit area owing to the very slow hydrolysis of PCL, a dilution effect on the concentration of l-PLA monolayers. Conversely the hydrolytic behavior of l-lactide-co-caprolactone (1/1 by mole) was similar to that of PCL even though the chemical compositions of the blend and the copolymer are very similar to each other. The resistance of the copolymer to hydrolysis might be attributed to the hydrophobicity and the steric hindrance of caprolactone unit in the copolymer.

Lee, W.K.; Gardella, J.A. Jr.

2000-04-04

142

Micro-thermal analysis of polyester coatings  

NASA Astrophysics Data System (ADS)

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.

Fischer, Hartmut R.

2010-04-01

143

Ignition characteristics of some aircraft interior fabrics  

NASA Technical Reports Server (NTRS)

Six samples of aircraft interior fabrics were evaluated with regard to resistance to ignition by radiant heat. Five samples were aircraft seat upholstery fabrics and one sample was an aircraft curtain fabric. The aircraft seat fabrics were 100% wool (2 samples), 83% wool/17% nylon, 49% wool/51% polyvinyl chloride, and 100% rayon. The aircraft curtain fabric was 92% modacrylic/8% polyester. The five samples of aircraft seat upholstery fabrics were also evaluated with regard to resistance to ignition by a smoldering cigarette. The four samples of wool-containing aircraft seat fabrics appeared to be superior to the sample of rayon seat fabric in resistance to ignition, both by radiant heat and by a smoldering cigarette.

Hilado, C. J.; Brandt, D. L.

1978-01-01

144

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

NASA Technical Reports Server (NTRS)

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.

Olson, L. H.

1981-01-01

145

Liquid crystalline aromatic polyesters containing isophthalic acid  

SciTech Connect

The authors have synthesized a series of copolyesters and terpolyesters containing the isophthalate unit in order to study the implications of nonlinear polymer backbones on liquid crystallinity. Copolyesters were prepared from isophthalic acid, hydroquinone, and terephthalic acid by melt polymerization. Poly(p-phenylene terephthalate-co-p-phenylene isophthalate)s with molar percentages of the p-phenylene isophthalate repeat unit ranging from 75 to 95 mol% exhibit melting temperatures near 350 C. The copolyester with 85 mol% of p-phenylene isophthalate exhibits a melting temperature of 355 C and a mesophase ranges of 30 C. Thermal properties of terpolyesters composed of four monomer units (isophthalic acid, hydroquinone, terephthalic acid, and p-hydroxybenzoic acid) show optimal compositions with melting temperatures below 350 C and wide mesophase ranges. The findings show that high contents of nonlinear monomers may be incorporated into polyesters without deleterious effects on liquid crystallinity in a composition range that can be processed at reasonable temperatures.

Cai, R. (Sherwin-Williams Co., Chicago, IL (United States)); Samulski, E.T. (Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Chemistry)

1994-01-01

146

21 CFR 177.2420 - Polyester resins, cross-linked.  

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

147

21 CFR 177.2420 - Polyester resins, cross-linked.  

Code of Federal Regulations, 2014 CFR

...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...

2014-04-01

148

21 CFR 177.2420 - Polyester resins, cross-linked.  

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

149

A biomedical library of serinol-derived polyesters.  

PubMed

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

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

2005-01-01

150

Appearance Performance of Fusible Interfacing Fabrics Attached to Home Sewn Cotton Blouses  

Microsoft Academic Search

A wear study was conducted to evaluate the appearance performance of five selected fusible interfacing fabrics of either a light or heavy weight, nonwoven, 50\\/50 nylon-polyester, or 45\\/45\\/10 nylon-polyester-rayon, each with a polyamide adhesive agent applied by the pinpointing method; or a 100 percent nylon knit with a polyamide adhesive applied by spray coating, attached to the front areas of

Mary M. Warnock; Mary E. Cotton

1985-01-01

151

Hydrolyzable polyester resins, varnishes and coating compositions containing the same  

DOEpatents

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.

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

1984-01-01

152

Influence of hyperbranched polyesters on the surface tension of polyols.  

PubMed

The influence of hyperbranched polyesters with different functional end groups on the surface tension of mixtures with an oligo(ester diol) was investigated. The temperature dependence of the surface tension of the pure components and of the mixtures was measured by a modified Wilhelmy balance technique. The results indicate that the surface tension of the pure hyperbranched polyesters strongly depends on the functionality of the end groups. The functionalization of the hydroxyl end groups by short alkyl chains (methyl, tert-butyl) reduced the surface tension depending on the degree of substitution. The surface tension of the mixtures with the hydroxyl-terminated hyperbranched polyester was slightly increased at higher concentrations of the hyperbranched polymer compared to the surface tension of the pure ester diol. On the other hand, the surface tension of mixtures could be considerably decreased using 1% of hyperbranched polyester polyols partially substituted with short alkyl chains. In that case, the modified hyperbranched polyesters act as surface active agents. On the molecular level, the enrichment of the modified hyperbranched polyester in the surface region was proven by X-ray photoelectron spectroscopy measurements. PMID:15350078

Ziemer, Antje; Azizi, Mazen; Pleul, Dieter; Simon, Frank; Michel, Stefan; Kreitschmann, Mirko; Kierkus, Paul; Voit, Brigitte; Grundke, Karina

2004-09-14

153

Rheological behaviour of nanocellulose reinforced unsaturated polyester nanocomposites.  

PubMed

Nanocellulose (NC) reinforced unsaturated polyester (UPR) composites were prepared by mechanical mixing process. Effect of isora nanocellulose on the properties of polyester composites has been studied in detail. Rheological properties of unsaturated polyester resin suspensions containing various amounts (0.5, 1 and 3wt%) of nanocellulose were investigated by oscillatory rheometer with parallel plate geometry. Analysis of curing revealed that the time required for gelation in NC filled UPR is lower than neat resin, which describe the catalytic action of NC on cure reaction. NC reinforced polyester suspensions showed shear thinning behaviour initially and at higher shear rates they showed Newtonian behaviour. Tensile and impact properties showed superior behaviour revealing improved interfacial bonding between nanofiller and the polymer matrix. With respect to the neat polyester the percentage increase in tensile strength of 0.5wt% NC reinforced composite is 57%. Optical and atomic force microscopic studies confirmed that the dispersion state of NC within the polyester matrix was adequate. Maximum glass transition temperature is obtained for 0.5wt% NC reinforced composite, which showed an increase of 10°C than neat resin. PMID:24877644

Chirayil, Cintil Jose; Mathew, Lovely; Hassan, P A; Mozetic, Miran; Thomas, Sabu

2014-08-01

154

78 FR 38939 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber (``PSF'') from the People's...1\\ See Certain Polyester Staple Fiber From the People's Republic...

2013-06-28

155

75 FR 76954 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Time Limit for...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...administrative review of certain polyester staple fiber (``PSF'') from the People's...May 31, 2009. See Certain Polyester Staple Fiber From the People's Republic...

2010-12-10

156

76 FR 2886 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results and Partial...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber (``PSF'') from the People's...PRC''). See Certain Polyester Staple Fiber From the People's Republic...

2011-01-18

157

75 FR 5763 - Notice of Correction to the First Administrative Review of Certain Polyester Staple Fiber From...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administrative Review of Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber from the People's Republic of...Administrative Review of Certain Polyester Staple Fiber From the People's Republic...

2010-02-04

158

75 FR 1336 - First Administrative Review of Certain Polyester Staple Fiber From the People's Republic of China...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administrative Review of Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber (``PSF'') from the People's...PRC''). See Certain Polyester Staple Fiber from the People's Republic...

2010-01-11

159

75 FR 34097 - Certain Polyester Staple Fiber From Taiwan: Extension of the Final Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of the Final...antidumping duty order on certain polyester staple fiber from Taiwan. See Certain Polyester Staple Fiber from Taiwan: Preliminary Results...

2010-06-16

160

78 FR 2366 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber (``PSF'') from the People's...1\\ See Certain Polyester Staple Fiber From the People's Republic...

2013-01-11

161

76 FR 69702 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber from the People's Republic of...1\\ See Certain Polyester Staple Fiber From the People's Republic...

2011-11-09

162

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

...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...

2010-07-02

163

Persistence of Nosocomial Pathogens on Various Fabrics  

PubMed Central

Objective: Fabrics can become contaminated with high numbers of microorganisms that may be pathogenic to patients in a hospital setting and can play an important role in the chain of infection. The aim of this study was to investigate the survival of several clinical bacterial and fungal isolates on several fabrics commonly used in hospitals. Materials and Methods: Bacterial and fungal survival was tested on the following materials, each of which are commonly used in our hospital: 100% smooth cotton, 60% cotton-40% polyester, 100% wool and 100% silk. One isolate each of Candida albicans, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis, Geotrichum candidum, Aspergillus fumigatus, Cryptococcus neoformans, vancomycin resistant Enterococcus faecium (VRE, methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase (ESBL) positive Escherichia coli, inducible beta-lactamase (IBL) positive Pseudomonas aeruginosa, IBL-positive Acinetobacter baumannii and Stenotrophomonas maltophilia were used to contaminate fabrics. The survival of these microorganisms was studied by testing the fabric swatches for microbial growth. Results: The median survival times for all the tested bacteria and fungi were as follows: 26 days on cotton, 26.5 days on cotton-polyester, 28 days on silk, and 30 days on wool. Among the bacterial species tested, E. faecium had the longest survival time on cotton-polyester fabrics. For the fungal isolates, it was observed that C. tropicalis and C. krusei survived for the shortest amount of time on cotton fabrics in the present study. Conclusion: This survival data indicate that pathogenic microorganisms can survive from days to months on commonly used hospital fabrics. These findings indicate that current recommendations for the proper disinfection or sterilization of fabrics used in hospitals should be followed to minimize cross-contamination and prevent nosocomial infections. PMID:25610201

Koca, Ozlem; Altoparlak, Ulku; Ayyildiz, Ahmet; Kaynar, Hasan

2012-01-01

164

Micro-mesh fabric pollination bags for switchgrass  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pollination bags for making controlled crosses between switchgrass plants were made from a polyester micro-mesh fabric with a mesh size of 41 µm which is smaller than the mean reported 43 µm diameter of switchgrass pollen. When used in paired plant crosses between switchgrass plants, the mean amoun...

165

EPA FABRIC FILTRATION STUDIES: 4. BAG AGING EFFECTS  

EPA Science Inventory

The report gives results of a study to determine the effects of aging on filter bags made of woven polyester. Fabric filter life can be divided into three periods: break-in, steady-state, and wear-out. During the break-in, both bag collection efficiency and the pressure drop acro...

166

Tunable chemical release from polyester thin film by photocatalytic zinc oxide and doped LiYF4 upconverting nanoparticles.  

PubMed

Once manufactured or implanted, polyester release kinetics tend to be fixed with little modulation possible for optimal local chemical concentrations. Here, a typical implantable polyester was fabricated into thin films (?50 ?m thick) with additives of photocatalytic ZnO nanoparticles, lanthanide-doped LiYF4 nanoparticle upconverting nanoparticles, or a combination thereof and irradiated with either 6 mW ultraviolet (365 nm) light emitting diodes or 50 mW near-infrared (980 nm) laser diodes to induce polymer photooxidation. Irradiated polyester films with the aforementioned photoadditives had enhanced release kinetics up to 30 times more than nonirradiated, neat films with extended release times of 28 days. Near-infrared, ZnO-mediated photocatalysis had the highest light on/light off ratio release kinetics of 15.4, while doped LiYF4 upconversion nanoparticles paired with ZnO nanoparticles had the highest linear R(2) correlation of 0.98 with respect to duty cycle and release kinetics. Future applications of the technology will aim toward modulation of previously developed polymeric reagents/drugs for real-time, feedback-optimized release. PMID:25474498

Cheng, Ting; Ortiz, Raphael Francois; Vedantham, Kumar; Naccache, Rafik; Vetrone, Fiorenzo; Marks, Robert S; Steele, Terry W J

2015-01-12

167

Electromagnetic shielding mechanisms using soft magnetic stainless steel fiber enabled polyester textiles  

NASA Astrophysics Data System (ADS)

This work studied the effects of conductivity, magnetic loss, and complex permittivity when using blended textiles (SSF/PET) of polyester fibers (PET) with stainless steel fibers (SSF) on electromagnetic wave shielding mechanisms at electromagnetic wave frequencies ranging from 30 MHz to 1500 MHz. The 316L stainless steel fiber used in this study had 38 vol% ? austenite and 62 vol% ?' martensite crystalline phases, which was characterized by an x-ray diffractometer. Due to the magnetic and dielectric loss of soft metallic magnetic stainless steel fiber enabled polyester textiles, the relationship between the reflection/absorption/transmission behaviors of the electromagnetic wave and the electrical/magnetic/dielectric properties of the SSF and SSF/PET fabrics was analyzed. Our results showed that the electromagnetic interference shielding of the SSF/PET textiles show an absorption-dominant mechanism, which attributed to the dielectric loss and the magnetic loss at a lower frequency and attributed to the magnetic loss at a higher frequency, respectively.

Shyr, Tien-Wei; Shie, Jing-Wen

2012-11-01

168

Magnetic birefringence in mixtures of a nematic aromatic polyester and PAA  

E-print Network

L-329 Magnetic birefringence in mixtures of a nematic aromatic polyester and PAA J. M. Gilli, GL The polyester DDA-9 has the chemical formula : n being the. degree of polymerization. The molecular weight

Boyer, Edmond

169

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

PubMed

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

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

2014-02-01

170

77 FR 54562 - Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...International Trade Administration [A-580-839] Certain Polyester Staple Fiber From the Republic of Korea: Rescission of Antidumping...administrative review of the antidumping duty order on certain polyester staple fiber from the Republic of Korea (``the Order'')....

2012-09-05

171

75 FR 47795 - Certain Polyester Staple Fiber from Korea: Rescission of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-839] Certain Polyester Staple Fiber from Korea: Rescission of Antidumping...2010). Scope of the Order Polyester staple fiber (``PSF'') covered by the scope of the order is defined as synthetic staple fibers, not carded, combed or...

2010-08-09

172

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...

173

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

Code of Federal Regulations, 2014 CFR

...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...

2014-07-01

174

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

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

175

Aliphatic polyester-grafted starch composites by in situ ring opening polymerization*  

E-print Network

Aliphatic polyester-grafted starch composites by in situ ring opening polymerization* Abstract cornponenls has been evidenced by SEM observations. Growth of the polyester chains on the starch granules has on the synthesis and characterization of aliphatic polyester- grafted Etarch (Scheme 1 ) by in s i f i i ROP of E

Narayan, Ramani

176

Modelling and simulation of an unsaturated polyester process. Geir Stian Landsverk1  

E-print Network

Modelling and simulation of an unsaturated polyester process. Geir Stian Landsverk1 , Thor Mejdell2 Most polyesters are produced by reacting different acid anhydrides or dicarboxylic acids with diols. In unsaturated polyester processes, most of the re- actions take place in the reactor and not in the col- umn

Foss, Bjarne A.

177

Characterisation of long term behaviour of polyester fibres and fibre assemblies for offshore mooring lines  

E-print Network

Characterisation of long term behaviour of polyester fibres and fibre assemblies for offshore have to be replaced. Polyester lines are being progressively introduced as a lighter alternative offset of the platform are some of the requirements. Polyester presents a fair compromise between

Burgoyne, Chris

178

78 FR 14512 - Certain Polyester Staple Fiber From the People's Republic of China: Preliminary Results and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber from the People's Republic of...subject to the order is certain polyester staple fiber.\\1\\ The product is...

2013-03-06

179

75 FR 6352 - Certain Polyester Staple Fiber from the People's Republic of China: Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber from the People's Republic of...administrative review of certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC. See Initiation...

2010-02-09

180

77 FR 25744 - Certain Polyester Staple Fiber From China; Institution of a Five-Year Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...731-TA-1104 (Review)] Certain Polyester Staple Fiber From China; Institution of a Five...antidumping duty order on certain polyester staple fiber from China would be likely to lead...order on imports of certain polyester staple fiber from China (72 FR 30545)....

2012-05-01

181

77 FR 19619 - Certain Polyester Staple Fiber from the People's Republic of China: Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber from the People's Republic of...administrative review of certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC.\\1\\ On...

2012-04-02

182

76 FR 7532 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...administrative review of certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC. See Initiation...

2011-02-10

183

76 FR 22366 - Certain Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Preliminary Results...antidumping duty order on certain polyester staple fiber (PSF) from Taiwan. The period...with respect to Nan Ya. See Polyester Staple Fiber from Taiwan: Rescission of...

2011-04-21

184

77 FR 6783 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...administrative review of certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC. See Initiation...

2012-02-09

185

75 FR 30373 - Certain Polyester Staple Fiber From the People's Republic of China: Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...administrative review of certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC. See Initiation...

2010-06-01

186

75 FR 51442 - Polyester Staple Fiber from Taiwan: Rescission of Antidumping Duty Administrative Review in Part  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Polyester Staple Fiber from Taiwan: Rescission of Antidumping...the antidumping duty order on polyester staple fiber from Taiwan. The period of review...the antidumping duty order on polyester staple fiber from Taiwan with respect to...

2010-08-20

187

77 FR 54561 - Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping...antidumping duty order on certain polyester staple fiber from Taiwan. The period of review...antidumping duty order on certain polyester staple fiber from Taiwan. See Certain...

2012-09-05

188

76 FR 52935 - Certain Polyester Staple Fiber From Korea: Rescission of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-839] Certain Polyester Staple Fiber From Korea: Rescission of Antidumping...of the antidumping order on polyester staple fiber from Korea. See Antidumping or...2011). Scope of the Order Polyester staple fiber covered by the scope of the...

2011-08-24

189

76 FR 57955 - Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Final Results of Antidumping...antidumping duty order on certain polyester staple fiber from Taiwan. The period of review...antidumping duty order on certain polyester staple fiber from Taiwan. See Certain...

2011-09-19

190

77 FR 62217 - Certain Polyester Staple Fiber From the People's Republic of China: Continuation of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC pursuant to...

2012-10-12

191

76 FR 11268 - Certain Polyester Staple Fiber From Korea and Taiwan  

Federal Register 2010, 2011, 2012, 2013, 2014

...polyester staple fiber from Korea and Taiwan...polyester staple fiber from Korea and Taiwan would be likely to...202-205- 1810. Persons with mobility impairments who will need special...polyester staple fiber from Korea and Taiwan (65 FR...

2011-03-01

192

Conversion of polyester/cotton industrial waste to higher value  

SciTech Connect

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.

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

1986-01-01

193

Additive effects on the toughening of unsaturated polyester resins  

SciTech Connect

An elastomer additive, carboxy-terminated acrylonitrile-butadiene copolymer, was used for toughening in the free radical cross-linking copolymerization of unsaturated polyester (UP) resins. For molded parts, Charpy impact behavior was generally enhanced and the number of catastrophic failures was reduced. The miscibility and interfacial properties of additive and resin blends play important roles in the toughening process. Phase-diagram studies showed that the elastomer additive is immiscible with the UP resin and is phase-separated from the resin matrix during curing. This phase-separation phenomenon is similar to that in the low-profile mechanism of UP resins. Additive-resin system miscibility greatly influences curing morphology. Microvoids occurred in the additive phase of cured resin because of shrinkage stress. The intrinsic inhomogeneity of the polyester network and the existence of microvoids in the final product limit the toughening effect of additives on unsaturated polyester resins. 49 refs., 13 figs., 3 tabs.

Suspene, L. [Centre de Recherches et de Technologies de Verneuil, Verneuil-en-Halatte (France); Yang, Y.S.; Pascault, J.P. [Institut National des Science Appliquees de Lyon, Villeurbanne (France)

1993-12-31

194

A new photosensitive dielectric insulating polyester film: Synthesis and characterization  

SciTech Connect

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.

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

1996-10-01

195

Influence of weft-knitted tubular fabric on radial mechanical property of coaxial three-layer small-diameter vascular graft.  

PubMed

The goal of this study was to evaluate the radial mechanical property of the small-diameter polyurethane vascular grafts reinforced by weft-knitted tubular polyester/spandex fabrics. The polyester/spandex tubular fabrics with different blend ratios were prepared on a weft-knitting machine to reinforce small-diameter polyurethane vascular grafts. Phase separation technique was employed to produce coaxial three-layer small-diameter polyurethane vascular grafts at room temperature. Morphology of the polyurethane vascular grafts was examined by scanning electron microscope (SEM), and micropores were observed on both inner and cross section surfaces. Radial tensile property and compliance of small-diameter polyurethane vascular grafts with and without reinforcement by polyester/spandex tubular fabrics were characterized. The effect of polyester/spandex tubular fabric on the mechanical property of polyurethane vascular grafts was studied. The results indicated that the radial tensile strength of the vascular graft was improved by the tubular fabric, and that the influence of tubular fabric on compliance was small compared to that of wall thickness. It was notable that the wall thickness of the vascular grafts was a major factor in controlling the compliance in the radial direction. Therefore, a coaxial three-layer small-diameter polyurethane vascular graft with excellent compliance and tensile strength could be obtained by controlling the wall thickness and using polyester/spandex fabric as reinforcement. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 342-349, 2012. PMID:22113920

Yang, Hongjun; Zhu, Guocheng; Zhang, Zhen; Wang, Zhenzhen; Fang, Jian; Xu, Weilin

2012-02-01

196

Polysilicon thin film transistors fabricated on low temperature plastic substrates  

SciTech Connect

We present device results from polysilicon thin film transistors (TFTs) fabricated at a maximum temperature of 100&hthinsp;{degree}C on polyester substrates. Critical to our success has been the development of a processing cluster tool containing chambers dedicated to laser crystallization, dopant deposition, and gate oxidation. Our TFT fabrication process integrates multiple steps in this tool, and uses the laser to crystallize deposited amorphous silicon as well as create heavily doped TFT source/drain regions. By combining laser crystallization and doping, a plasma enhanced chemical vapor deposition SiO{sub 2} layer for the gate dielectric, and postfabrication annealing at 150&hthinsp;{degree}C, we have succeeded in fabricating TFTs with I{sub ON}/I{sub OFF} ratios {gt}5{times}10{sup 5} and electron mobilities {gt}40 cm{sup 2}/V&hthinsp;s on polyester substrates. {copyright} {ital 1999 American Vacuum Society.}

Carey, P.G.; Smith, P.M.; Theiss, S.D.; Wickboldt, P. [Lawrence Livermore National Laboratory, P. O. Box 808, L-271, Livermore, California 94551 (United States)] [Lawrence Livermore National Laboratory, P. O. Box 808, L-271, Livermore, California 94551 (United States)

1999-07-01

197

Dynamic mechanical analysis of banana fiber reinforced polyester composites  

Microsoft Academic Search

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?

Laly A. Pothan; Zachariah Oommen; Sabu Thomas

2003-01-01

198

Dielectric behavior of polycarbon/polyester mixtures upon transesterification  

SciTech Connect

Dielectric spectroscopy was used to characterize the structural changes which occur upon annealing in polycarbonate/polyester mixtures. The mixtures, which are normally immiscible, become homogeneous due to transesterification when heated to 220{degrees}C. We observe a corresponding increase in both the glass transition temperature and the dispersion magnitude ({eta}{sub 0}-{eta}{sub {infinity}}).

Factor, B.J.; Mopsik, F.I.; Han, C.C. [NIST, Gaithersburg, MD (United States)

1995-12-31

199

Synthesis, structure and properties of polyhydroxyalkanoates: biological polyesters  

Microsoft Academic Search

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.

K Sudesh; H Abe; Y Doi

2000-01-01

200

Bacterial and other biological systems for polyester production  

Microsoft Academic Search

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

Alexander Steinbüchel; Bernd Füchtenbusch

1998-01-01

201

Alkali treatment of coir fibres for coir-polyester composites  

Microsoft Academic Search

Coir fibres were subjected to alkali treatment with a view to improving the wettability of coir fibres by a commercially available resin such as polyester. Tensile strength of the fibres increases by 15% when the fibres are soaked in 5% aqueous solution of NaOH at 28±1° C for 72 to 76 h after which it shows a gradual decrease. This

S. V. Prasad; C. Pavithran; P. K. Rohatgi

1983-01-01

202

Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete  

DOEpatents

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.

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

1983-05-13

203

INTERFACIAL ADHESION IN POLYSTYRENE/BIODEGRADABLE POLYESTER BLENDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biodegradable polyesters (BPEs) have unique combinations of biodegradability, biocompatibility and water-resistance properties. As a result, BPEs are being actively developed as blend components of natural polymers such as starch, to improve its water-resistance. BPEs are also being developed as b...

204

Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete  

DOEpatents

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.

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

1981-11-04

205

Degradation Characterization of Aliphatic POLYESTERS—IN Vitro Study  

NASA Astrophysics Data System (ADS)

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.

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

2008-08-01

206

Lipase-catalyzed polyester synthesis – A green polymer chemistry  

PubMed Central

This article is a short comprehensive review describing in vitro polyester synthesis catalyzed by a hydrolysis enzyme of lipase, most of which has been developed for these two decades. Polyesters are prepared by repeated ester bond-formation reactions; they include two major modes, ring-opening polymerization (ROP) of cyclic monomers such as cyclic esters (lactones) and condensation polymerization via the reaction between a carboxylic acid or its ester group and an alcohol group. Polyester synthesis is, therefore, a reaction in reverse way of in vivo lipase catalysis of ester bond-cleavage with hydrolysis. The lipase-catalyzed polymerizations show very high chemo-, regio-, and enantio-selectivities and involve various advantageous characteristics. Lipase is robust and compatible with other chemical catalysts, which allows novel chemo-enzymatic processes. New syntheses of a variety of functional polyesters and a plausible reaction mechanism of lipase catalysis are mentioned. The polymerization characteristics are of green nature currently demanded for sustainable society, and hence, desirable for conducting ‘green polymer chemistry’. PMID:20431260

Kobayashi, Shiro

2010-01-01

207

Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete  

DOEpatents

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.

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

1985-01-01

208

Amphiphilic Dendritic Molecules: Hyperbranched Polyesters with Alkyl-Terminated Branches  

E-print Network

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

Vakni, David

209

Systematic investigation of drip stains on apparel fabrics: The effects of prior-laundering, fibre content and fabric structure on final stain appearance.  

PubMed

Bloodstain pattern analysis is the investigation of blood deposited at crime scenes and the interpretation of that pattern. The surface that the blood gets deposited onto could distort the appearance of the bloodstain. The interaction of blood and apparel fabrics is in its infancy, but the interaction of liquids and apparel fabrics has been well documented and investigated in the field of textile science (e.g. the processes of wetting and wicking of fluids on fibres, yarns and fabrics). A systematic study on the final appearance of drip stains on torso apparel fabrics (100% cotton plain woven, 100% polyester plain woven, blend of polyester and cotton plain woven and 100% cotton single jersey knit) that had been laundered for six, 26 and 52 cycles prior to testing was investigated in the paper. The relationship between drop velocity (1.66±0.50m/s, 4.07±0.03m/s, 5.34±0.18m/s) and the stain characteristics (parent stain area, axes 1 and 2 and number of satellite stains) for each fabric was examined using analysis of variance. The experimental design and effect of storing blood were investigated on a reference sample, which indicated that the day (up to five days) at which the drops were generated did not affect the bloodstain. The effect of prior-laundering (six, 26 and 52 laundering cycles), fibre content (cotton vs. polyester vs. blend) and fabric structure (plain woven vs. single jersey knit) on the final appearance of the bloodstain were investigated. Distortion in the bloodstains produced on non-laundered fabrics indicated the importance of laundering fabrics to remove finishing treatments before conducting bloodstain experiments. For laundered fabrics, both the cotton fabrics and the blend had a circular to oval stain appearance, while the polyester fabric had a circular appearance with evidence of spread along the warp and weft yarns, which resulted in square-like stains at the lowest drop velocity. A significant (p<0.001) increase in the stain size on laundered blend fabric was identified. Bloodstain characteristics varied due to fibre content (p<0.001) and fabric structure (p<0.001). Blood on polyester fabric, after impact, primarily moved due to capillary force and wicking of the blood along the fibres/yarns, while for the cotton fabrics wicking was accompanied by movement of blood into the fibres/yarns. This study highlights the importance for forensic analysts of apparel evidence to consider the age, the fibre type and the fabric structure before interpreting bloodstain patterns. PMID:25828382

de Castro, Therese C; Taylor, Michael C; Kieser, Jules A; Carr, Debra J; Duncan, W

2015-05-01

210

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

211

Fabrication and characterization of particulate polymer nanocomposites  

NASA Astrophysics Data System (ADS)

A comprehensive series of experiments are conducted to study dynamic crack initiation and propagation in nanocomposite materials. The nanocomposites are fabricated using ultrasonics with an in-situ polymerization technique to produce materials with excellent particle dispersion, as verified by transmission electron microscopy and scanning electron microscopy. Dynamic fracture toughness testing is carried out on three-point bend nanocomposite specimens using a modified split-Hopkinson pressure bar. Dynamic photoelasticity coupled with high-speed photography has also been used to obtain crack tip velocities and dynamic stress fields around the propagating cracks. A relationship between the dynamic stress intensity factor, KD, and the crack tip velocity, a?, is established. Three different sizes Al2O3 particles were chosen as the reinforcement to fabricate the 1 vol.% polyester/A1 2O3 nanocomposites. A series of experiments were conducted to study the effect of the size of filler particles on fracture behavior of the composites. High strain rate testings conducted using a split Hopkinson preesure bar apparatus revealed a moderate increase in fracture toughness with the decrease of particle size. These three composites were also characterized for the dynamic fracture constitutive behavior. Birefringent coating technique coupled with high-speed photography was employed in this study to obtain the dynamic stress fields around the propagating crack tips. A relationship between the dynamic stress intensity factor K1, and the crack tip velocity, a?, was established and compared for all three materials. Multi-walled carbon nanotube (MWNT)/polyester composites were fabricated successfully using the in-situ method combined with the sonication technique. The nanotubes were pre-treated and functionalized to make them more soluble to the matrix material before added into the polyester resin. TEM analysis was carried out to verify the dispersion of the nanotubes in the composites. Three volume fractions (0.1%, 0.5% and 1%) MWNT/polyester nanocomposites were fabricated and subsequently characterized on mechanical behaviors. The results showed the great increase in static fracture toughness of the composites, while decrease in compression strength, compared with the virgin polyester specimens. The transport properties of the carbon nanotubes/polymer composites, including the electrical conductivity and the thermal conductivity, were reviewed and suggestions were given for the future researches.

Du, Ying

2007-06-01

212

Mechanical Behavior of Fabric-Film Laminates  

NASA Technical Reports Server (NTRS)

Inflatable structures are gaining wide support in planetary scientific missions as well as commercial applications. For such applications a new class of materials made of laminating thin homogenous films to lightweight fabrics are being considered us structura1 gas envelops. The emerging composite materials are a result of recent advances in the manufacturing cf 1ightweight, high strength fibers, fabrics and scrims. The lamination of these load-carrying members with the proper gas barrier film results in wide range of materials suitable for various loading and environmental conditions. Polyester - based woven fabrics laminated to thin homogeneus film of polyester (Maylar) is an example of this class. This fabric/ film laminate is being considered for the development a material suitable for building large gas envelopes for use in the NASA Ultra Long Duration Balloon Program (ULDB). Compared to commercial homogeneus films, the material provides relatively high strength to weight ratio as well as better resistance to crack and tear propagation. The purpose of this papers is to introduce the mechanical behavior of this class of multi-layers composite and to highlight some of the concerns observed during the characterization of these laminate composites.

Said, Magdi S.

1999-01-01

213

Assessment of a Polyester-Covered Nitinol Stent in the Canine Aorta and Iliac Arteries  

SciTech Connect

Purpose: To evaluate the patency and healing characteristics of a woven polyester fabric-covered stent in the canine model.Methods: Twenty-four self-expanding covered stents were placed in the infrarenal aorta and bilateral common iliac arteries of eight dogs and evaluated at 1 (n = 2), 3 (n = 2), and 6 (n = 4) months. Stent assessment was done using angiography prior to euthanasia, and light and scanning electron microscopy.Results: Angiographically, just prior to euthanasia, 8 of 8 aortic and 14 of 16 iliac endovascular covered stents were patent. Histologically, the stented regions showed complete endothelialization 6 months after graft implantation. A neointima had formed inside the stented vessel regions resulting in complete encasement of the fabric-covered stent by 3 months after graft implantation. Medial compression with smooth muscle cell atrophy was present in all stented regions. Explanted stent wires, examined by scanning electron microscopy, showed pitting but no cracks or breakage.Conclusion: The covered stent demonstrated predictable healing and is effective in preventing stenosis in vessels 10.0 mm or greater in diameter but does not completely preclude stenosis in vessels 6.0 mm or less in diameter.

Castaneda, Flavio [Department of Radiology, University of Illinois College of Medicine at Peoria, 1 Illini Drive, Peoria, IL 61656 (United States); Ball-Kell, Susan M. [Department of Pathology, University of Illinois College of Medicine at Peoria, 1 Illini Drive, Peoria, IL 61656 (United States); Young, Kate; Li Ruizong [Department of Radiology, University of Illinois College of Medicine at Peoria, 1 Illini Drive, Peoria, IL 61656 (United States)

2000-09-15

214

Thermo-mechanical properties of polyester mortar using recycled PET  

SciTech Connect

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.

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

1997-07-01

215

Biosynthesis and Biodegradation of 3-Hydroxypropionate- Containing Polyesters?  

PubMed Central

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

Andreeßen, Björn; Steinbüchel, Alexander

2010-01-01

216

Biocatalytic polyester acrylation--process optimization and enzyme stability.  

PubMed

An OH-functional polyester has been acrylated via transesterification of ethyl acrylate, catalyzed by Candida antarctica lipase B (CalB) in two different preparations: Novozym 435 and immobilized on Accurel MP1000. The batch process resulted in incomplete acrylation as well as severe degradation of the polyester. A high degree of acrylation was achieved by optimization through the application of low pressure (15 kPa), continuous inflow of ethyl acrylate and continuous distillation to evaporate the by-product, ethanol. The enzyme preparations displayed good stability with half-lives of 180 and 324 h for Novozym 435 and CalB/MP1000, respectively. This translates into product yields of 3600 and 6200 times the weight of the catalyst, indicating that the enzyme will have a marginal impact on the total process cost. PMID:18821636

Hagström, Anna E V; Nordblad, Mathias; Adlercreutz, Patrick

2009-02-15

217

Amino alcohol-based degradable poly(ester amide) elastomers  

PubMed Central

Currently available synthetic biodegradable elastomers are primarily composed of crosslinked aliphatic polyesters, which suffer from deficiencies including (1) high crosslink densities, which results in exceedingly high stiffness, (2) rapid degradation upon implantation, or (3) limited chemical moieties for chemical modification. Herein, we have developed poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate)s, a new class of synthetic, biodegradable elastomeric poly(ester amide)s composed of crosslinked networks based on an amino alcohol. These crosslinked networks feature tensile Young’s modulus on the order of 1 MPa and reversable elongations up to 92%. These polymers exhibit in vitro and in vivo biocompatibility. These polymers have projected degradation half-lives up to 20 months in vivo. PMID:18295329

Bettinger, Christopher J.; Bruggeman, Joost P.; Borenstein, Jeffrey T.; Langer, Robert S.

2009-01-01

218

Statistical variability in the strength and failure strain of aramid and polyester yarns  

Microsoft Academic Search

The scatter in the failure strain, load and stress of high-tenacity polyester and aramid yarns is studied experimentally. From the data, the failure strains of polyester and aramid yarns can be fitted to a two-parameter Weibull distribution. However, the log-log dependence of the strain on the gauge length is best represented by the Watson-Smith modification. Whereas the strengths of polyester

G. Amaniampong; C. J. Burgoyne

1994-01-01

219

Hydrolytic ageing of polyester networks - Role of a plasticizer  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

220

Impact response of thick glass fibre reinforced polyester laminates  

Microsoft Academic Search

Thick glass\\/polyester woven roving laminated plates subject to low-velocity impact have been investigated using a guided drop-weight test rig in ascending energy order up to 1500 J. The impact response and energy-absorbing characteristics have been determined by impact-forces and absorbed-energy histories, and by force-displacement relationships. Impact damage is examined by visual inspection, ultrasonic C-scan and an optical microscope so that

G. Zhou; G. A. O. Davies

1995-01-01

221

Biodiversity of microorganisms that degrade bacterial and synthetic polyesters  

Microsoft Academic Search

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

J Mergaert; J Swings

1996-01-01

222

Adhesive behavior of aluminum layers evaporated on polyester films  

SciTech Connect

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.}

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

223

Stabilizing polymorphic transitions of tristearin using diacylglycerols and sucrose polyesters  

Microsoft Academic Search

The polymorphic transitions of synthesized tristearin in the presence of selected DAG or commercial sucrose polyesters (SPE)\\u000a were investigated using DSC and X-ray diffractiometry. The stabilizing effects of DAG and SPE on ? to ? transitions of tristearin\\u000a were dependent on the chemical structures of additives such as FA chain length, saturation of FA, positions and number of\\u000a FA on

Jun-Hyun Oh; Alan R. McCurdy; Stephanie Clark; Barry G. Swanson

2005-01-01

224

Adhesive behavior of aluminum layers evaporated on polyester films  

NASA Astrophysics Data System (ADS)

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)

Vallat, M. F.; Haidara, H.; Ziegler, P.; Rey, D.; Papirer, Y.; Schultz, J.

1996-01-01

225

Compressive and ultrasonic properties of polyester\\/fly ash composites  

Microsoft Academic Search

The addition of hollow fillers having appropriate mechanical properties can decrease the density of the resulting composite,\\u000a called syntactic foams, while concurrently improving its mechanical properties. In this study, hollow fly ash particles, called\\u000a cenospheres, are used as fillers in polyester matrix material. Cenospheres are a waste by-product of coal combustion and,\\u000a as such, are available at very low cost.

Pradeep K. Rohatgi; Takuya Matsunaga; Nikhil Gupta

2009-01-01

226

Biodegradation of aliphatic polyester composites reinforced by abaca fiber  

Microsoft Academic Search

The composites of aliphatic polyesters (poly(?-caprolactone) (PCL), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(butylene succinate) (PBS), and poly(lactic acid) (PLA)) with 10 wt.% untreated or acetic anhydride-treated (AA-) abaca fibers were prepared and their biodegradability was evaluated by the soil-burial test. In case of PCL composites, the presence of untreated abaca or AA-abaca did not pronouncedly affect the weight loss because PCL itself has

Naozumi Teramoto; Kohei Urata; Koichi Ozawa; Mitsuhiro Shibata

2004-01-01

227

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

NASA Astrophysics Data System (ADS)

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.

Boykin, Timothy Lamar

228

Synthesis of aliphatic polyesters by polycondensation using inorganic acid as catalyst.  

PubMed

An effective route for the synthesis of aliphatic polyesters made from adipic or sebacic acid and alkanediols, using inorganic acid as a catalyst is reported. The monomer composition, reaction time, catalyst type, and reaction conditions were optimized to yield polyesters with weight average molecular weights of 23,000 for adipic acid and 85,000 for sebacic acid-based polyesters. The polymers melt at temperatures of 52-65°C and possess melt viscosity in the range of 5600-19,400cP. This route represents an alternative method for producing aliphatic polyesters for possible use in the preparation of degradable disposable medical supplies. PMID:25473252

Sokolsky-Papkov, Marina; Langer, Robert; Domb, Abraham J

2011-04-01

229

NIR Characterization and Measurement of the Cotton Content of Dyed Blend Fabrics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Near Infrared (NIR) spectroscopy has been used extensively for several years in the fiber, textiles, and textile auxiliaries industries. NIR techniques for the measurement of cotton-polyester (PET) blend content have concentrated on yarn slivers and greige fabrics rather than the more much difficult...

230

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...

231

A novel method for applying reduced graphene oxide directly to electronic textiles from yarns to fabrics.  

PubMed

Conductive, flexible, and durable reduced RGO textiles with a facile preparation method are presented. BSA proteins serve as universal adhesives for improving the adsorption of GO onto any textile, irrespective of the materials and the surface conditions. Using this method, we successfully prepared various RGO textiles based on nylon-6 yarns, cotton yarns, polyester yarns, and nonwoven fabrics. PMID:23946273

Yun, Yong Ju; Hong, Won G; Kim, Wan-Joong; Jun, Yongseok; Kim, Byung Hoon

2013-10-25

232

Use of Fabric and Plastic Barriers to Control Weeds in Blackberries  

Technology Transfer Automated Retrieval System (TEKTRAN)

Weed control in blackberries (Rubus spp.) is a serious problem for organic producers and those who wish to reduce their reliance on herbicides. Three landscape fabrics (Dewitt, Texel, and a white polyester weave) and one industrial grade white on black plastic were used in conjuction with newly pla...

233

Modification of cellulosic fabric using polyvinyl alcohol, Part-II: Colorfastness properties  

Microsoft Academic Search

A series of aqueous solutions of poly (vinyl alcohol) of various commercial products were prepared and applied onto the surfaces of cotton and blends of cotton\\/polyester fabrics. Fourier Transform Infrared spectrophotometer was used to confirm the molecular structure of the polyvinyl alcohol used. Performance tests such as colorfastness to rubbing (dry and wet) and colorfastness to washing were determined. The

Mohammad Zuber; Khalid Mahmood Zia; Ijaz Ahmad Bhatti; Tahir Jamil; Ali Rizwan

234

Cyclic swelling as a phenomenon inherent to biodegradable polyesters.  

PubMed

The aim of this study is to evaluate and describe the phenomenon and mechanism of the spontaneous cyclic swelling and deswelling of linear and branched aliphatic polyesters in the aqueous medium. The fluctuation of gel volume in one or several cycles as an inherent property of biodegradable and bioerodible materials has not yet been described. We have observed the process at linear and branched polyesters of aliphatic ?-hydroxy acids. The period of duration of cycles was in order of hours to days, as influenced by the size of the bodies ranging from 25 to 1000 mg, the temperature in the range of 7°C-42°C, ionic strength, and pH value. The results demonstrated that swelling is accompanied by hydrolysis of ester bonds with the development of small water-soluble osmotically active molecules. After reaching a higher degree of swelling, the obstruction effect of the gel decreases and the diffusion of soluble degradation products from the body to the environment prevails. A decrease in osmotic pressure inside the body and a decrease in the hydrophilic character of the gel matrix result in deswelling by a collapse of the structure, probably due to hydrophobic interactions of nonpolar polyester chains. PMID:25241844

Dittrich, Milan; Snejdrova, Eva

2014-11-01

235

Nanoencapsulation of a water soluble drug in biocompatible polyesters. Effect of polyesters melting point and glass transition temperature on drug release behavior.  

PubMed

Five polyesters based on 1,3-propanediol or ethylene glycol and an aliphatic dicarboxylic acid were used for the preparation of Ropinirole HCl-loaded nanoparticles. The advantage of the present study is that the used polyesters - as well as poly(lactic acid) (PLA) - have similar degree of crystallinity but different melting points, varying from 46.7 to 166.4°C. Based on polymer toxicity on HUVEC, the biocompatibility of these aliphatic polyesters was found comparable to that of PLA and thus the studied polyesters could be used as drug carriers. Drug encapsulation in polyesters was performed via emulsification/solvent evaporation method. Particle size of drug-loaded nanoparticles was between 140 and 190 nm, as measured by light scattering. Drug loading content for all the polyesters varies between 10 and 16% and their entrapment efficiency is relatively high (32-48%). WAXD patterns of nanoparticles show that Ropinirole HCl lies in amorphous state within polymer matrices. Drug release diagrams reveal that the higher percentage of Ropinirole HCl is released during the first 6h after its insertion in the dissolution medium. Fast release rates of the drug are attributed to high hydrophilicity of Ropinirole HCl. Melting point (T(m)) and glass transition temperature (T(g)) of the host polymer matrices seem to be important parameters, since higher drug release rates are observed in polyesters with low T(m) and T(g). PMID:20863892

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

2010-12-23

236

Solid-State 13C NMR of Liquid Crystalline Polyesters: Variations in Morphology, Alignment, and Dynamics within a Homologous Series  

E-print Network

Solid-State 13C NMR of Liquid Crystalline Polyesters: Variations in Morphology, Alignment, the structures of these polyesters were examined by high-resolution solid-state 13C NMR. It was found that while

Frydman, Lucio

237

75 FR 70906 - Certain Polyester Staple Fiber From the People's Republic of China: Partial Rescission of the...  

Federal Register 2010, 2011, 2012, 2013, 2014

...International Trade Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of China: Partial Rescission...Review'' of the antidumping duty order on certain polyester staple fiber (``PSF'') from the People's Republic of...

2010-11-19

238

76 FR 60802 - Certain Polyester Staple Fiber From the Republic of Korea and Taiwan: Continuation of Antidumping...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Certain Polyester Staple Fiber From the Republic of Korea and Taiwan: Continuation of Antidumping Duty Orders AGENCY...on certain polyester staple fiber from the Republic of Korea (Korea) and Taiwan would likely lead to a continuation or...

2011-09-30

239

In-situ measurement of processing properties during fabrication in a production tool  

NASA Technical Reports Server (NTRS)

Progress is reported on the use of frequency-dependent electromagnetic measurements (FDEMs) as a single, convenient technique for continuous in situ monitoring of polyester cure during fabrication in a laboratory and manufacturing environment. Preliminary FDEM sensor and modeling work using the Loss-Springer model in order to develop an intelligent closed-loop, sensor-controlled cure process is described. FDEMs using impedance bridges in the Hz to MHz region is found to be ideal for automatically monitoring polyester processing properties continuously throughout the cure cycle.

Kranbuehl, D. E.; Haverty, P.; Hoff, M.; Loos, A. C.

1988-01-01

240

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

SciTech Connect

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.

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

1989-05-01

241

Facile Functionalization of Polyesters through Thiol-yne Chemistry for the Design of Degradable, Cell-Penetrating and Gene Delivery  

E-print Network

Facile Functionalization of Polyesters through Thiol-yne Chemistry for the Design of Degradable, China *S Supporting Information ABSTRACT: Synthesis of polyesters bearing pendant amine groups. Polyesters are a class of well-known biodegradable materials and have been extensively used in controlled

Cheng, Jianjun

242

Role of silanes in adhesion. Part II. Dynamic mechanical properties of silane-treated glass fiber\\/polyester composites  

Microsoft Academic Search

—Glass fiber\\/unsaturated polyester composites, prepared by impregnating glass braid with varying thickness coatings (from 200 Å up to 1600 Å thick) of polyester resin, were tested with a DuPont Dynamic Mechanical Analyzer. The effects of the polyester resin thickness and silane treatments on the dynamic mechanical properties of the composites were evaluated. The results are supported by Fourier transform infrared

Yona Eckstein

1989-01-01

243

77 FR 50530 - Polyester Staple Fiber From China; Scheduling of an Expedited Five-Year Review Concerning the...  

Federal Register 2010, 2011, 2012, 2013, 2014

...731-TA-1104 (Review)] Polyester Staple Fiber From China; Scheduling of an Expedited...the Antidumping Duty Order on Polyester Staple Fiber From China AGENCY: United States...the antidumping duty order on polyester staple fiber from China would be likely to...

2012-08-21

244

77 FR 21733 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of Time...antidumping duty order on certain polyester staple fiber from Taiwan for the period May 1...30, 2011.\\1\\ In Certain Polyester Staple Fiber From Taiwan: Extension of...

2012-04-11

245

77 FR 71579 - Polyester Staple Fiber From Taiwan: Notice of Court Decision Not in Harmony With Final Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-583-833] Polyester Staple Fiber From Taiwan: Notice of Court Decision...the antidumping duty order on polyester staple fiber from Taiwan covering the period...Sawblades). \\6\\ See Certain Polyester Staple Fiber From Taiwan: Final Results of...

2012-12-03

246

77 FR 54898 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Expedited...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...antidumping duty order on certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC would be likely...

2012-09-06

247

76 FR 28420 - Certain Polyester Staple Fiber From the People's Republic of China: Full Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic of...administrative review of certain polyester staple fiber from the People's Republic of...antidumping duty order on certain polyester staple fiber from the PRC. See Initiation...

2011-05-17

248

75 FR 64252 - Certain Polyester Staple Fiber From the Republic of Korea: Final Results of the 2008-2009...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-580-839] Certain Polyester Staple Fiber From the Republic of Korea: Final...antidumping duty order on certain polyester staple fiber from the Republic of Korea and invited...Department'') published Certain Polyester Staple Fiber from the Republic of Korea:...

2010-10-19

249

76 FR 37830 - Polyester Staple Fiber From Korea and Taiwan; Scheduling of Expedited Five-Year Reviews...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Polyester Staple Fiber From Korea and Taiwan; Scheduling of Expedited...Polyester Staple Fiber From Korea and Taiwan AGENCY: United States...polyester staple fiber from Korea and Taiwan would be likely to...202-205-1810. Persons with mobility impairments who will need...

2011-06-28

250

Adhesive for polyester films cures at room temperature, has high initial tack  

NASA Technical Reports Server (NTRS)

Quick room-temperature-cure adhesive bonds polyester-insulated flat electrical cables to metal surfaces and various other substrates. The bond strength of the adhesive may be considerably increased by first applying a commercially available polyamide primer to the polyester film.

Christian, C. M.; Fust, G. W.; Welchel, C. J.

1966-01-01

251

Studies on mechanical performance of biofibre\\/glass reinforced polyester hybrid composites  

Microsoft Academic Search

The degree of mechanical reinforcement that could be obtained by the introduction of glass fibres in biofibre (pineapple leaf fibre\\/sisal fibre) reinforced polyester composites has been assessed experimentally. Addition of relatively small amount of glass fibre to the pineapple leaf fibre and sisal fibre-reinforced polyester matrix enhanced the mechanical properties of the resulting hybrid composites. Different chemically modified sisal fibres

S Mishra; A. K Mohanty; L. T Drzal; M Misra; S Parija; S. K Nayak; S. S Tripathy

2003-01-01

252

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...

253

N d'ordre : 2012-ISAL-0071 Nanostructuration de rsines polyester insatur  

E-print Network

N° d'ordre : 2012-ISAL-0071 Année 2012 Thèse Nanostructuration de résines polyester insaturé par-0071 Année 2012 Thèse Nanostructuration de résines polyester insaturé par des copolymères à blocs

Paris-Sud XI, Université de

254

Some Mechanical Properties of Mylar and Dacron Polyester Strands at Low Temperatures  

Microsoft Academic Search

Dacron polyester fiber and Mylar polyester sheet were tested in tension ; and impact at four temperatures: 296 deg k 228 deg K, 195 deg K, and 76 deg K. ; Dacron strand increased in ultimate strength as the temperature decreased, while ; Mylar ultimate strength dropped. Both fibers showed less elongation at lower ; temperatures. Mylar at low temperatures

R. P. Reed; R. P. Mikesell

1958-01-01

255

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...

256

Controlled hydrogenative depolymerization of polyesters and polycarbonates catalyzed by ruthenium(II) PNN pincer complexes.  

PubMed

Ruthenium(II) PNN complexes depolymerize many polyesters into diols and polycarbonates into glycols plus methanol via hydrogenation. Notably, polyesters with two methylene units between ester linkages depolymerize to carboxylic acids rather than diols. This methodology represents a new approach for producing useful chemicals from waste plastics. PMID:24647792

Krall, Eric M; Klein, Tyler W; Andersen, Ryan J; Nett, Alex J; Glasgow, Ryley W; Reader, Diana S; Dauphinais, Brian C; Mc Ilrath, Sean P; Fischer, Anne A; Carney, Michael J; Hudson, Dylan J; Robertson, Nicholas J

2014-05-18

257

EVALUATION OF POLYESTER AND METALLIZED-POLYETHYLENE FILMS FOR CHEMICAL PROTECTIVE CLOTHING APPLICATIONS  

EPA Science Inventory

The permeation resistance of thin polyester films and metallized, low-density polyethylene (LDPE) films was evaluated to assess their feasibility for use in chemical protective clothing applications. For a 0.002 cm polyester film, permeation tests were conducted with acetone, car...

258

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

PubMed Central

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

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

2013-01-01

259

Hygrothermomechanical evaluation of transverse filament tape epoxy/polyester fiberglass composites  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

260

Mechanical and Tear Properties of Fabric/Film Laminates  

NASA Technical Reports Server (NTRS)

Films reinforced with woven fabrics are being considered for the development of a material suitable for long duration scientific balloons under a program managed by the National Aeronautics and Space Administration (NASA). Recently developed woven fabrics provide a relatively high strength to weight ratio compared to standard homogenous films. Woven fabrics also have better crack propagation resistance and rip stop capabilities when compared to homogenous lightweight, high strength polymeric films such as polyester and nylon. If joining is required, such as in the case of scientific balloons, woven fabrics have the advantage over polymeric thin films to utilize traditional textile methods as well as other techniques including hot sealing, adhesion, and ultrasonic means. Woven fabrics, however, lack the barrier properties required for helium filled scientific balloons, therefore lamination with homogenous films is required to provide the gas barrier capabilities required in these applications.

Said, Magdi A.

1998-01-01

261

Composite material from recycled polyester for recyclable automobile structures  

SciTech Connect

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.

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

1995-12-31

262

Biosynthesis of lactate-containing polyesters by metabolically engineered bacteria.  

PubMed

Due to increasing concerns about environmental problems, climate change and limited fossil resources, bio-based production of chemicals and polymers is gaining attention as one of the solutions to these problems. Polyhydroxyalkanoates (PHAs) are polyesters that can be produced by microbial fermentation. PHAs are synthesized using monomer precursors provided from diverse metabolic pathways and are accumulated as distinct granules inside the cells. On the other hand, most so-called bio-based polymers including polybutylene succinate, polytrimethylene terephthalate, and polylactic acid (PLA) are synthesized by a chemical process using monomers produced by fermentation. PLA, an attractive biomass-derived plastic, is currently synthesized by heavy metal-catalyzed ring opening polymerization of L-lactide that is made from fermentation-derived L-lactic acid. Recently, a complete biological process for the production of PLA and PLA copolymers from renewable resources has been developed by direct fermentation of recombinant bacteria employing PHA biosynthetic pathways coupled with a novel metabolic pathway. This could be accomplished by establishing a pathway for generating lactyl-CoA and engineering PHA synthase to accept lactyl-CoA as a substrate combined with systems metabolic engineering. In this article, we review recent advances in the production of lactate-containing homo- and co-polyesters. Challenges remaining to efficiently produce PLA and its copolymers and strategies to overcome these challenges through metabolic engineering combined with enzyme engineering are discussed. PMID:22057878

Park, Si Jae; Lee, Sang Yup; Kim, Tae Wan; Jung, Yu Kyung; Yang, Taek Ho

2012-02-01

263

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

PubMed

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

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

2011-07-01

264

Microbial degradation of aliphatic and aliphatic-aromatic co-polyesters.  

PubMed

Biodegradable plastics (BPs) have attracted much attention since more than a decade because they can easily be degraded by microorganisms in the environment. The development of aliphatic-aromatic co-polyesters has combined excellent mechanical properties with biodegradability and an ideal replacement for the conventional nondegradable thermoplastics. The microorganisms degrading these polyesters are widely distributed in various environments. Although various aliphatic, aromatic, and aliphatic-aromatic co-polyester-degrading microorganisms and their enzymes have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. In this review, we have reported some new microorganisms and their enzymes which could degrade various aliphatic, aromatic, as well as aliphatic-aromatic co-polyesters like poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(?-caprolactone) (PCL), poly(ethylene succinate) (PES), poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate) and poly(3-hydoxybutyrate-co-3-hydroxyvalterate) (PHB/PHBV), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(butylene adipate-co-terephthalate (PBAT), poly(butylene succinate-co-terephthalate) (PBST), and poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL). The mechanism of degradation of aliphatic as well as aliphatic-aromatic co-polyesters has also been discussed. The degradation ability of microorganisms against various polyesters might be useful for the treatment and recycling of biodegradable wastes or bioremediation of the polyester-contaminated environments. PMID:24522729

Shah, Aamer Ali; Kato, Satoshi; Shintani, Noboru; Kamini, Numbi Ramudu; Nakajima-Kambe, Toshiaki

2014-04-01

265

Comportement mecanique des joints boulonnes en composites verre-polyester  

NASA Astrophysics Data System (ADS)

Glass fibre-reinforced polyester composite materials are being extensively used for general-purpose applications. For highly loaded structures, bolted joints are generally the preferred assembly method. However, bolted joints are usually the weakest link in a structure and they must therefore be designed with care. Specifically, the joint geometry, reinforcement type and lay-up should be chosen on a rational basis, otherwise the assembly may fail prematurely. The present study is concerned with the study of these material parameters. The mechanical response of bolted assemblies is studied for a range of six glass fibre-reinforced polyester laminates with reinforcements and lay-ups that are typical for general-purpose applications. In order to assess how changes in joint width or in joint end distance affect the behaviour of the joint, tests were carried out on three coupon geometries. In accordance with the standard test method ASTM D5961, a single-bolt double lap bolted joint configuration was used for the experimental characterisation. We investigated how the displacement measurement could best be made because currently there is a whole range of approaches in use and it is clear that the measured displacement quantity directly affects the stiffness values. A 3-D finite element model indicated that bolt deformation and fixture deformations affected the measured coupon displacement. The bearing stiffness was reduced by 26% on average when the width was reduced from six to two times the hole diameter. For the assemblies with a width of two times the hole diameter (w/D = 2) the bearing stiffness increased clearly with the tensile modulus of the tested materials. Both the experimental and numerical bearing stiffness values were much lower than those predicted by joint flexibility formulas. Hence, our results indicate that these joint flexibility formulas should be adapted if they are intended to be used for design of general-purpose glass fibre-reinforced polyester structures with bolt-hole clearance. The different material/geometry combinations led to very diverse failure modes and strengths, ranging from catastrophic low strength failures to progressive high strength failures. All the small coupons (w/D = 2; e/D = 3) failed catastrophically by tension. We observed that important characteristics of the bearing response such as damage stress, ultimate strength, failure mode and post-failure behaviour were related to reinforcement types and their stacking sequence. (Abstract shortened by UMI.)

Vangrimde, Bart

266

Microwave dielectrometry measurements of glass reinforced polyester resins  

SciTech Connect

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.

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

1999-10-01

267

Biodegradable polyesters containing ibuprofen and naproxen as pendant groups  

PubMed Central

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

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

2013-01-01

268

Polyester Sulphonic Acid Interstitial Nanocomposite Platform for Peroxide Biosensor  

PubMed Central

A novel enzyme immobilization platform was prepared on a platinum disk working electrode by polymerizing aniline inside the interstitial pores of polyester sulphonic acid sodium salt (PESA). Scanning electron microscopy study showed the formation of homogeneous sulphonated polyaniline (PANI) nanotubes (?90 nm) and thermogravimetric analysis (TGA) confirmed that the nanotubes were stable up to 230 °C. The PANI:PESA nanocomposite showed a quasi-reversible redox behaviour in phosphate buffer saline. Horseradish peroxidase (HRP) was immobilized on to this modified electrode for hydrogen peroxide detection. The biosensor gave a sensitivity of 1.33 ?A (?M)-1 and a detection limit of 0.185 ?M for H2O2. Stability experiments showed that the biosensor retained more than 64% of its initial sensitivity over four days of storage at 4 °C. PMID:22303157

Al-Ahmed, Amir; Ndangili, Peter M.; Jahed, Nazeem; Baker, Priscilla G. L.; Iwuoha, Emmanuel I.

2009-01-01

269

Polyester-based thin films with high photosensitivity  

SciTech Connect

A great deal of research has been done to understand the photosensitive optical response of inorganic glasses, which exhibit a permanent, photo-induced refractive index change due to the presence of optically active point defects in the glass structure. In the present work, the authors have performed a preliminary study of the intrinsic photosensitivity of a polyester containing a cinnamylindene malonate group (CPE, a photo- and thermal-crosslinkable group) for use in photonic waveguide devices. Thin films of CPE (approximately 0.5 microns thick) were spun onto fused silica substrates. Optical absorption in the thin films was evaluated both before and after exposure to UV radiation sources. It was found that the polyester exhibits two dominant UV absorption bands centered about 240 nm and 330 nm. Under exposure to 337 nm radiation (nitrogen laser) a marked bleaching of the 330 nm band was observed. This band bleaching is a direct result of the photo-induced crosslinking in the cinnamylindene malonate group. Exposure to 248 nm radiation (excimer laser), conversely, resulted in similar bleaching of the 330 nm band but was accompanied by nearly complete bleaching of the higher energy 240 nm band. Based on a Kramers-Kronig analysis of the absorption changes, refractive index changes on the order of {minus}10{sup {minus}2} are estimated. Confirmation of this calculation has been provided via ellipsometry which estimates a refractive index change at 632 nm of {minus}0.061 {+-} 0.002. Thus, the results of this investigation confirm the photosensitive potential of this type of material.

POTTER,KELLY SIMMONS; POTTER JR.,BARRETT G.; WHEELER,DAVID R.; JAMISON,GREGORY M.

2000-02-29

270

Reinforcement mechanism of polyester-fiber-reinforced rubber--a model study  

SciTech Connect

The reinforcement mechanism of polyester tire cord was studied by Fourier-transform infrared spectroscopy using various model compounds. Three model compounds representing the main chain of polyester and the terminal groups, namely carboxylic acid and hydroxyl groups, were used. Chemical reactions between these polyester models and an epoxy functional silane coupling agent were studied qualitatively as well as quantitatively. Among the many possible reactions, the reaction between the carboxylic acid and epoxy group was found to proceed readily. Kinetic studies of the major reactions also show quantitative differences in their activation energies as well as the rate constants. Based on the quantitative studies, we have estimated the expected rate of interfacial reaction at the heat treating temperature of polyester tire cord.

Xue, G.; Koenig, J.L.; Wheeler, D.D.; Ishida, H.

1983-08-01

271

A kinetic study of hydrolysis of polyester elastomer in magnetic tape  

NASA Technical Reports Server (NTRS)

A useful method for kinetic study of the hydrolysis of polyester elastomer is established which uses the number-average molecular weight. The reasonableness of this method is confirmed and the effect of magnetic particles on hydrolysis is considered.

Yamamoto, K.; Watanabe, H.

1994-01-01

272

Redox-Responsive, Core Cross-Linked Polyester Micelles Zhonghai Zhang,,,  

E-print Network

copolymer, was synthesized by means of ring- opening polymerization of 5-(4-(prop-2-yn-1-yloxy)benzyl)-1 polyesters to allow formation of micelles with cross-linkable cores. Effort has been devoted to the synthesis

Cheng, Jianjun

273

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

E-print Network

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 ...

Brigham, Christopher J.

274

The influence of fibre treatment on the performance of coir-polyester composites  

Microsoft Academic Search

Surface modifications of coir fibres involving alkali treatment, bleaching, and vinyl grafting are made in view of their use as reinforcing agents in general-purpose polyester resin matrix. The mechanical properties of composites like tensile, flexural and impact strength increase as a result of surface modification. Among all modifications, bleached (65°C) coir-polyester composites show better flexural strength (61.6 MPa) whereas 2%

J. Rout; M. Misra; S. S. Tripathy; S. K. Nayak; A. K. Mohanty

2001-01-01

275

Preparation and photopolymerization behavior of multifunctional thiol–ene systems based on hyperbranched aliphatic polyesters  

Microsoft Academic Search

A multifunctional polythiol based on hyperbranched polyester Boltorn™ H40 (thioglycolic actate of H40), and two multi-ene hyperbranched polyesters based on Boltorn™ H20 and P1000 (allyl ether terminal functionalized H20 and norbornene end-capped P1000) were synthesized and characterized by 1H NMR spectral analysis. The UV-induced photopolymerization behavior of multifunctional thiol–ene system, including those oligomers synthesized above, a tri-functional thiol, a tetra-allyl

Qi Fu; Jianhua Liu; Wenfang Shi

2008-01-01

276

The lipid polyester composition of Arabidopsis thaliana and Brassica napus seeds  

Microsoft Academic Search

Mature seeds of Arabidopsis thaliana and Brassica napus contain a complex mixture of aliphatic monomers derived from the non-extractable lipid polyesters deposited by various seed tissues. Methods of polyester depolymerization of solvent-extracted seeds and analysis of aliphatic monomers were compared. Sodium methoxide-catalyzed depolymerization, followed by GC analysis of the acetylated monomers, was developed for routine quantitative analysis suitable for 0.5g

Isabel Molina; Gustavo Bonaventure; John Ohlrogge; Mike Pollard

2006-01-01

277

Phase inversion and its effect on the properties of polyester polyurethane cationomers  

Microsoft Academic Search

Polyester polyurethane cationomers are prepared using polyester polyol of molecular weight 2000 as soft segments, N-methyl diethanolamine as chain extender, glycolic acid as quaternization agent, methyl ethyl ketone as solvent, and 4,4'-diphenylenemethylene diisocyanate (MDI) as diisocyanate. Properties of the films cast from solutions and emulsions are studied by infrared spectroscopy, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, and tensile-elongation

Fu-Hu Su; Show-An Chen; Wu Chung Chan

1994-01-01

278

Biocompatibility of sorbitol-containing polyesters. Part I: Synthesis, surface analysis and cell response in vitro  

Microsoft Academic Search

A series of sorbitol-containing polyesters were synthesized via a one-pot lipase-catalyzed condensation polymerization. Thin films were prepared by spin coating on silicon wafers and surfaces were analyzed by tapping mode atomic force microscopy and contact angle measurements. Surface morphologies and surface energies across the series of polyester films, including a poly(?-caprolactone) (PCL) control were nearly indistinguishable. Biocompatibility of the sorbitol-containing

Ying Mei; Ajay Kumar; Wei Gao; Richard Gross; Scott B. Kennedy; Newell R. Washburn; Eric J. Amis; John T. Elliott

2004-01-01

279

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

PubMed Central

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

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

2014-01-01

280

Degradation behaviors of polyester monolayers at the air\\/water interface: Alkaline and enzymatic degradations  

Microsoft Academic Search

The degradation kinetics of Langmuir monolayer films of a series of biodegradable polyesters has been studied to investigate the effect of degradation medium, alkalinity and enzymes. The degradation behavior of polyester monolayers strongly depended on both degradation medium and surface pressure. As the surface pressure was increased, the degradation rates of poly(l-lactide) (PLLA) and poly[(R)-3-hydroxybutyrate] (P(3HB)) increased in both degradation

Nam-Ju Jo; Tadahisa Iwata; Kwon Taek Lim; Sin-Hye Jung; Won-Ki Lee

2007-01-01

281

Temperature dependence of the emission of perchloroethylene from dry-cleaned fabrics  

SciTech Connect

The article discusses an evaluation of the emission of perchloroethylene (tetrachloroethylene) from freshly dry cleaned fabrics using small environmental test chambers. The temperature dependence of the release of perchloroethylene was evaluated over a temperature range of 20 to 45 C. A linear relation exists between the logarithm of perchloroethylene retention time and the reciprocal of the absolute temperature. Study results for 100% wool and 55% polyester/45% wool indicate that airing out freshly dry cleaned fabrics at above ambient temperature will increase the rate at which perchloroethylene is emitted from the fabrics.

Guo, Z.; Tichenor, B.A.; Mason, M.A.; Plunket, C.M.

1990-01-01

282

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

PubMed Central

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

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

2011-01-01

283

Antimicrobial hyperbranched poly(ester amide)/polyaniline nanofiber modified montmorillonite nanocomposites.  

PubMed

There has been growing interest in the use of nanomaterials featuring potent of antimicrobial activity in the biomedical domain. It still remains a challenge for the researchers to develop an efficient nanocomposite possessing antimicrobial efficacy against broad spectrum microbes including bacteria, fungi as well as algal consortium, posing serious challenges for the human survival. In addressing the above problem, we report the fabrication of bio-based hyperbranched poly(ester amide) (HBPEA)/polyaniline nanofiber modified montmorillonite (MMT) nanocomposites by an ex-situ polymerization technique at varied weight percentages (1, 2.5, 5 wt.%) of the modified MMT (nanohybrid). The Fourier transform infrared spectroscopy confirmed the structural changes upon interaction of the nanohybrid with HBPEA. A probable mechanism is proposed for the formation of nanocomposites with partially exfoliated nanoplatelet structure, which was further confirmed from the high resolution transmission electron microscopic analyses. The prepared nanocomposites exhibited potent efficacy against gram positive bacteria like Bacillus subtilis and Staphylococcus aureus as compared to the gram negative ones like Pseudomonas aeruginosa and Escherichia coli. The nanocomposites showed significant antifungal activity against Aspergillus niger, Fusarium oxysporum and Coleotricum capcii and antialgal activity against algal consortium comprising of Chlorella, Hormidium and Cladophorella species. The formation of thermosetting nanocomposites resulted in the acceptable improvement of desired physico-chemical and mechanical properties including thermostability. Thus pronounced antimicrobial activity of the nanocomposites against a spectrum of bacterial and fungal strains as well as a consortium of algal species along with other desired performance vouched them as potent antimicrobial materials in the realm of health and biomedical industry. PMID:24411352

Pramanik, Sujata; Bharali, Pranjal; Konwar, B K; Karak, Niranjan

2014-02-01

284

Additives in fibers and fabrics.  

PubMed Central

The additives and contaminants which occur in textile fibers vary widely, depending on the type of fiber and the pretreatment which it has received. Synthetic fibers such as nylon and polyester contain trace amounts of contaminants such as catalysts and catalyst deactivators which remain after the synthesis of the basic polymers. In addition, there are frequently a number of materials which are added to perform specific functions in almost all man-made fibers. Examples of these would include traces of metals or metal salts used as tracers for identification of specific lots of fiber, TiO2 or similar materials added as delustrants, and a host of organic species added for such special purposes as antistatic agents or flame retardants. There may also be considerable quantities of residual monomer or small oligomers dissolved in the polymer matrix. The situation becomes even more complex after the fibers are converted into fabric form. Numerous materials are applied at various stages of fabric preparation to act as lubricants, sizing agents, antistats, bleaches, and wetting agents to facilitate the processing, but these are normally removed before the fabric reaches the cutters of the ultimate consumers and therefore usually do not constitute potential hazards. However, there are many other chemical agents which are frequently added during the later stages of fabric preparation and which are not designed to be removed. Aside from dyes and printing pigments, the most common additive for apparel fabrics is a durable press treatment. This generally involves the use of materials capable of crosslinking cellulosics by reacting through such functions as N-methylolated amides or related compounds such as ureas and carbamates. These materials pose some potential hazards due to both the nitrogenous bases and the formaldehyde which they usually release. There is usually also some residual catalyst in fabrics which have received such treatments. Other types of chemical treatments which are often applied to fabrics to achieve special effects include flame retardants, soil release agents, antistatic agents, softeners, water and/or oil repellents, ultraviolet absorbers, bacteriostats, and fungistats. PMID:1242130

Barker, R H

1975-01-01

285

Fabric Architecture  

NSDL National Science Digital Library

Published by the Industrial Fabrics Association International, Fabric Architecture magazine is published bimonthly and is distributed to over 13000 architects working in the field. For those who've never thought about the possibilities and opportunities afforded by this area that straddles the lines between fabrics, design, and architecture, it's quite a find. On this page, users can look through materials that address topics like tents, lightweight structures, graphics, awnings, and truck covers. After perusing these areas, visitors should delve into the current issue. The archives here date back to 2006, and the topics covered within these pages include fabrics in the workplace, flexible design materials, and creating a "green" car park with various fabrics. For those who are interested, there's also information about how to subscribe to the print edition of the magazine.

286

Aliphatic polyester block polymers: renewable, degradable, and sustainable.  

PubMed

Nearly all polymers are derived from nonrenewable fossil resources, and their disposal at their end of use presents significant environmental problems. Nonetheless, polymers are ubiquitous, key components in myriad technologies and are simply indispensible for modern society. An important overarching goal in contemporary polymer research is to develop sustainable alternatives to "petro-polymers" that have competitive performance properties and price, are derived from renewable resources, and may be easily and safely recycled or degraded. Aliphatic polyesters are particularly attractive targets that may be prepared in highly controlled fashion by ring-opening polymerization of bioderived lactones. However, property profiles of polyesters derived from single monomers (homopolymers) can limit their applications, thus demanding alternative strategies. One such strategy is to link distinct polymeric segments in an A-B-A fashion, with A and B chosen to be thermodynamically incompatible so that they can self-organize on a nanometer-length scale and adopt morphologies that endow them with tunable properties. For example, such triblock copolymers can be useful as thermoplastic elastomers, in pressure sensitive adhesive formulations, and as toughening modifiers. Inspired by the tremendous utility of petroleum-derived styrenic triblock copolymers, we aimed to develop syntheses and understand the structure-property profiles of sustainable alternatives, focusing on all renewable and all readily degradable aliphatic polyester triblocks as targets. Building upon oxidation chemistry reported more than a century ago, a constituent of the peppermint plant, (-)-menthol, was converted to the ?-caprolactone derivative menthide. Using a diol initiator and controlled catalysis, menthide was polymerized to yield a low glass transition temperature telechelic polymer (PM) that was then further functionalized using the biomass-derived monomer lactide (LA) to yield fully renewable PLA-PM-PLA triblock copolymers. These new materials were microphase-separated and could be fashioned as high-performing thermoplastic elastomers, with properties comparable to commercial styrenic triblock copolymers. Examination of their hydrolytic degradation (pH 7.4, 37 °C) revealed retention of properties over a significant period, indicating potential utility in biomedical devices. In addition, they were shown to be useful in pressure-sensitive adhesives formulations and as nucleating agents for crystallization of commercially relevant PLA. More recently, new triblocks have been prepared through variation of each of the segments. The natural product ?-methylene-?-butyrolactone (MBL) was used to prepare triblocks with poly(?-methylene-?-butyrolactone) (PMBL) end blocks, PMBL-PM-PMBL. These materials exibited impressive mechanical properties that were largely retained at 100 °C, thus offering application advantages over triblock copolymers comprising poly(styrene) end blocks. In addition, replacements for PM were explored, including the polymer derived from 6-methyl caprolactone (MCL). In sum, success in the synthesis of fully renewable and degradable ABA triblock copolymers with useful properties was realized. This approach has great promise for the development of new, sustainable polymeric materials as viable alternatives to nonrenewable petroleum-derived polymers in numerous applications. PMID:24852135

Hillmyer, Marc A; Tolman, William B

2014-08-19

287

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

PubMed

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

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

2011-04-01

288

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

PubMed

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

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

2015-01-01

289

Tearing resistance of some co-polyester sheets  

SciTech Connect

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.

Kim, Ho Sung; Karger-Kocsis, Jozsef

2004-06-07

290

Viscoelastic properties of kenaf reinforced unsaturated polyester composites  

NASA Astrophysics Data System (ADS)

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.

Osman, Ekhlas A.; Mutasher, Saad A.

2014-03-01

291

Engineered Thermobifida fusca cutinase with increased activity on polyester substrates.  

PubMed

A bacterial cutinase from Thermobifida fusca, named Tfu_0883, was genetically modified by site-directed mutagenesis to enhance its activity on poly(ethylene terephthalate) (PET). The new mutations tailored the catalytic site for PET, increasing the affinity of cutinase to this hydrophobic substrate and the ability to hydrolyze it. The mutation I218A was designed to create space and the double mutation Q132A/T101A was designed both to create space and to increase hydrophobicity. The activity of the double mutant on the soluble substrate p-nitrophenyl butyrate increased two-fold compared to wild-type cutinase, while on PET both single and double mutants exhibited considerably higher hydrolysis efficiency. The replacement of specific amino acids at the active site was an effective approach for the improvement of the Tfu_0883 cutinase capacity to hydrolyze polyester surfaces. Thus, this study provides valuable insight on how the function and stability of enzymes can be improved by molecular engineering for their application in synthetic fiber biotransformation. PMID:21751386

Silva, Carla; Da, Shi; Silva, Nádia; Matamá, Teresa; Araújo, Rita; Martins, Madalena; Chen, Sheng; Chen, Jian; Wu, Jing; Casal, Margarida; Cavaco-Paulo, Artur

2011-10-01

292

Identification and comparison of cutinases for synthetic polyester degradation.  

PubMed

Cutinases have been exploited for a broad range of reactions, from hydrolysis of soluble and insoluble esters to polymer synthesis. To further expand the biotechnological applications of cutinases for synthetic polyester degradation, we perform a comparative activity and stability analysis of five cutinases from Alternaria brassicicola (AbC), Aspergillus fumigatus (AfC), Aspergillus oryzae (AoC), Humicola insolens (HiC), and the well-characterized Fusarium solani (FsC). Of the cutinases, HiC demonstrated enhanced poly(?-caprolactone) hydrolysis at high temperatures and under all pH values, followed by AoC and AfC. Both AbC and FsC are least stable and function poorly at high temperatures as well as at acidic pH conditions. Surface charge calculations and phylogenetic analysis reveal two important modes of cutinase stabilization: (1) an overall neutral surface charge within the "crowning area" by the active site and (2) additional disulfide bond formation. These studies provide insights useful for reengineering such enzymes with improved function and stability for a wide range of biotransformations. PMID:21713515

Baker, Peter James; Poultney, Christopher; Liu, Zhiqiang; Gross, Richard; Montclare, Jin Kim

2012-01-01

293

Compression-shear study of glass reinforced polyester  

NASA Astrophysics Data System (ADS)

Fiber reinforced organic matrix composites, due to their lower density, are being considered for armor applications where weight is an important factor. In this work, shock wave experiments were performed on Glass Reinforced Polyester (GRP) composite to investigate delamination due to normal and off-axis impact. This study extends the prior work of Dandekar and Beaulieu which examined both the compressive and tensile strengths of GRP under normal loading conditions. Symmetric impact shock wave experiments were performed on a 102 mm slotted barrel single-stage light gas gun over a range of obliquity to 26 degrees. Oblique impact geometry was chosen to investigate the shear strain dependence of the delamination process. Particle velocity history was measured by VISAR and the "pull-back" signal typifying delamination provided a measure of the delamination strength. Delamination was detected from measurements of the particle velocity history using VISAR. Delamination values as low as 0.007 GPa were recorded for shock stress of 0.103 GPa and obliquity of 26 degrees. Overall the delamination threshold in GRP was observed to decrease with increasing obliquity, suggesting shear strain dependence. These results will be discussed and the experimental details describing the compression-shear experimental arrangement will be provided.

Boteler, J. Michael

1998-07-01

294

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

NASA Astrophysics Data System (ADS)

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.

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

2004-07-01

295

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

PubMed Central

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

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

2011-01-01

296

Mechanical performance of hybrid polyester composites reinforced Cloisite 30B and kenaf fibre  

NASA Astrophysics Data System (ADS)

Hybridization of rubber toughened polyester-kenaf nanocomposite was prepared by adding various percentage of kenaf fiber with 4% Cloisite 30B in unsaturated polyester resin. Composite were prepared by adding filler to modified polyester resin subsequently cross-linked using methyl ethyl ketone peroxide and the accelerator cobalt octanoate 1%. Three per hundred rubbers (phr) of liquid natural rubber (LNR) were added in producing this composite. This composite expected to be applied in the interior of passenger cars and truck cabins. This is a quality local product from a combination of good properties polyester and high performance natural fiber, kenaf that is suitable for many applications such as in automotive sector and construction sector. The mechanical and thermal properties of composite were characterized using Durometer Shore-D hardness test, Izod impact test, Scanning electron microscopy, thermogravimetry (TGA) and differential scanning calorimetry (DSC). Result shows that addition of LNR give good properties on impact, flexural and hardness compare to without LNR composite. DSC curve shows that all composition of composites is fully cured and good in thermal properties. Addition of higher percentage of kenaf will lead the composite to elastic behavior and decrease the toughened properties of the composite. Hybrid system composite showed the flexural properties within the flexural properties of kenaf - polyester and Cloisite 30B.

Bonnia, N. N.; Surip, S. N.; Ratim, S.; Mahat, M. M.

2012-06-01

297

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

PubMed

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

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

2011-01-01

298

76 FR 38612 - Certain Polyester Staple Fiber From the Republic of Korea and Taiwan: Final Results of the...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-580-839, A-583-833] Certain Polyester Staple Fiber From the Republic of Korea and Taiwan...the antidumping duty orders on polyester staple fiber (PSF) from the Republic of Korea...orders is PSF. PSF is defined as synthetic staple fibers, not carded, combed or...

2011-07-01

299

76 FR 5331 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...International Trade Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary...administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan for the period May 1, 2009, through...

2011-01-31

300

77 FR 4543 - Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...International Trade Administration [A-583-833] Certain Polyester Staple Fiber From Taiwan: Extension of Time Limit for Preliminary...administrative review of the antidumping duty order on certain polyester staple fiber from Taiwan for the period May 1, 2010, through...

2012-01-30

301

Novel L-DOPA-derived poly(ester amide)s: monomers, polymers, and the first L-DOPA-functionalized biobased adhesive tape.  

PubMed

The synthesis, characterization, and testing of a range of novel bio-inspired L-DOPA-derived poly(ester amide)s is presented, using a widely applicable, straightforward chemistry. A model system is used to study and establish the monomer and polymer synthetic protocols, and to provide a set of optimum reaction conditions. It is further shown that fully biobased L-DOPA-containing adhesive tapes can be fabricated, which are positively evaluated in terms of their adhesive properties. The newly developed synthetic protocol constitutes a versatile platform for accessing and tailoring a plethora of relevant structures, including a variety of potentially biocompatible poly(ethylene glycol)-based materials. PMID:24265232

Manolakis, Ioannis; Noordover, Bart A J; Vendamme, Richard; Eevers, Walter

2014-01-01

302

Aliphatic polyester polymer stars: synthesis, properties and applications in biomedicine and nanotechnology.  

PubMed

A critical review: the ring-opening polymerization of cyclic esters provides access to an array of biodegradable, bioassimilable and renewable polymeric materials. Building these aliphatic polyester polymers into larger macromolecular frameworks provides further control over polymer characteristics and opens up unique applications. Polymer stars, where multiple arms radiate from a single core molecule, have found particular utility in the areas of drug delivery and nanotechnology. A challenge in this field is in understanding the impact of altering synthetic variables on polymer properties. We review the synthesis and characterization of aliphatic polyester polymer stars, focusing on polymers originating from lactide, ?-caprolactone, glycolide, ?-butyrolactone and trimethylene carbonate monomers and their copolymers including coverage of polyester miktoarm star copolymers. These macromolecular materials are further categorized by core molecules, catalysts employed, self-assembly and degradation properties and the resulting fields of application (262 references). PMID:21082079

Cameron, Donald J A; Shaver, Michael P

2011-03-01

303

Physical Aging, Coreset Curl, and Stress Relaxation of PETG Polyester  

NASA Astrophysics Data System (ADS)

The effect of temperature and time on the physical aging and coreset curl of PETG polyester has been measured and analyzed.Coreset curl measurements were carried out over a temperature range of 21 to 80 C and for times extending up to one year at room temperature. The Struik analysis was successfully applied to the measured stress relaxation behavior of PETG films and combined with the coreset curl model of Greener, et al.,to predict long-term coreset curl of PETG at room temperature. For freshly quenched films, an aging rate parameter of 0.55 and a Kohlrausch-Williams-Watts (KWW) parameter of 0.4 fit both the stress relaxation and coreset curl data quantitatively. Higher values of beta were needed to fit the coreset behavior of films that had aged at room temperature prior to being wound on a core. Independently, enthalpy relaxation measurements were carried out on PETG and were analyzed using the physical aging model of Tool and Narayanaswamy (TN). The TN model was then combined with the coreset curl model of Greener, et al., to make predictions of the long time coreset curl response of PETG at temperatures ranging from 21 to 80 C. For freshly quenched films, the activation energy, H=210kcal/mol determined from DSC and the KWW exponent, beta=0.4 determine from stress-relaxation were used in the TN approach to fit the room temperature coreset curl data as well as to successfully predict the higher-temperature coreset curl behavior. Fitting the TN model to the coreset behavior of films that had aged at room temperature prior to being wound on a core required that both the aging rate as well as the KWW relaxation function parameter beta be changed, which indicates that not only has the aging rate lengthened with room temperature aging prior to winding, but the nature of the relaxation function has changed as well.

Massa, Dennis J.; O'Reilly, James M.; Perchak, Dennis R.; Gillmor, Jeffrey R.

2000-03-01

304

Effect of chemical treatment of aramid fibres on their adhesion performance with polyester resin  

SciTech Connect

Aramid fibers were chemically treated to improve their wetting characteristics and to selectively bond suitable coupling agents to their surface. It was found that an organic coupling agent, which had been reactively bonded to the surface of the aramid fibers and contained an unsaturated pendant group, not only significantly improved the wetting performance of the fibers but also increased the adhesion of polyester resin to the fibers by approximately 200%. This increase in adhesion is attributed primarily to chemical rather than physical bonding. It is suggested that the unsaturated end groups of the attached coupling agent cross-link with the polyester resin during the curing process.

Stevens, M.G.; Massoudi, A.H. [Univ. of Technology, Sydney (Australia). Dept. of Materials Science

1993-12-31

305

Simulation of Stress-Strain Curves of Polyester and Viscose Filaments  

NASA Astrophysics Data System (ADS)

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.

Ghosh, Anindya; Das, Subhasis; Saha, Bapi

2014-11-01

306

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

PubMed

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

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

2014-07-23

307

OGP Functionalized Phenylalanine-Based Poly(ester urea) for Enhancing Osteoinductive Potential of Human Mesenchymal Stem Cells.  

PubMed

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

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

2015-04-13

308

Dielectric investigation of some woven fabrics  

NASA Astrophysics Data System (ADS)

In this paper, we have investigated the temperature dependence of dielectric properties (relative dielectric permeabilities and dielectric tangents of losses) for woven fabrics of hemp, jute, flax, cotton, polyester (PES), cotton-PES mixture, and wool. The measurements have been carried out at a temperature range from -50 to 50 °C in the electric periodic field at a frequency 1 MHz in vacuum. For the same specimens, the values of the dielectric properties have also been measured at an air temperature of 21 °C and at relative humidities of 40%, 60%, and 80%. At different frequencies from 80 kHz to 5 MHz, the dielectric properties have been measured at a relative humidity of 40% and at a temperature of 21 °C. An investigation of the dielectric properties of woven fabrics can provide a better understanding of the relation between the dielectric properties of woven fabrics and the different raw material compositions, temperatures, relative air humidities, and frequencies for specimens. Hence, this investigation helps to improve textile material properties.

Cerovic, Dragana D.; Dojcilovic, Jablan R.; Asanovic, Koviljka A.; Mihajlidi, Tatjana A.

2009-10-01

309

The Mechanical Behaviour of Single-tricot Warp-knitted Fabrics Part I: An Experimental Investigation of Knitted Fabrics of Varying Loop Geometry under Tensile Stress with Special Attention Given to Inter-yarn Friction  

Microsoft Academic Search

Single-tricot warp-knitted structures made from polyester-fibre (PET-fibre) yarns are analysed for their geometrical properties and their uniaxial tensile behaviour. A detailed study is devoted to the inter-yarn friction in these structures, since yarn slippage is one of the effects dominating large-scale deformations of the fabrics. Both static (initiation of slippage) and sliding (ongoing slippage) friction were investigated. The results of

H. Stumpf; T. Lenz; K. Schulte; C.-H. Andersson

1999-01-01

310

Special Considerations in Selection of Fabric Film Laminates for Use in Inflatable Structures  

NASA Technical Reports Server (NTRS)

Inflatable structures are gaining wide support in planetary scientific missions as well as commercial applications. For such applications a new class of fabric/film laminates is being considered for use as a structural gas envelope. The emerging composite materials are a result of recent advances in the manufacturing of lightweight, high strength fibers, fabrics and scrims. The lamination of these load-carrying members with the proper gas barriers results in a wide range of materials suitable for various loading and environmental conditions. Polyester-based woven fabrics laminated to thin homogenous film of polyester are an example of this class. This fabric/film laminate is being considered for the development of a material suitable for building large gas envelopes for use in the NASA ultra long duration balloon program (ULDB). Compared to commercial homogenous films, the material provides relatively high strength to weight ratio as well as better resistance to crack and tear propagation, The mechanical, creep and viscoelastic properties of these fabric film laminates have been studied to form a material model. Preliminary analysis indicates that the material is highly viscoelastic. The mechanical properties of this class of materials will be discussed in some details.

Said, Magdi A.

1999-01-01

311

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 ...

312

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

Microsoft Academic Search

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,

Gerardo Montero; David Hinks; Jacob Hooker

2003-01-01

313

Multiple transverse fracture in 90° cross-ply laminates of a glass fibre-reinforced polyester  

Microsoft Academic Search

Specimens of a 90° cross-ply glass-reinforced polyester were tested in tension in a direction parallel to one of the directions of reinforcement. Extensive cracking of the transverse ply occurred at strains much lower than the resin failure strain. These cracks formed in a direction parallel to the transverse reinforcement and showed a remarkably even crack spacing. Results of crack spacing

K. W. Garrett; J. E. Bailey

1977-01-01

314

Investigation of the wear behaviour of a glass-fibre-reinforced composite and plain polyester resin  

Microsoft Academic Search

In industrial applications, the increase in the use of composite materials means that it is necessary to know their behaviour under working conditions. Wear is an important parameter and its experimental behaviour must be known. In this study, the wear behaviour of a glass-fibre-reinforced composite and plain polyester resin are experimentally investigated for speeds of 500 and 710 rpm and

Ha?im P?ht?l?; Nihat Tosun

2002-01-01

315

QUANTITATIVE ULTRAVIOLET SPECTROSCOPY IN WEATHERING OF A MODEL POLYESTER-URETHANE COATING. (R828081E01)  

EPA Science Inventory

Spectroscopy was used to quantify the effects of ultraviolet light on a model polyester–urethane coating as it degraded in an accelerated exposure chamber. An explorative calculation of the effective dosage absorbed by the coatings was made and, depending on the quantum...

316

Processability and properties of aliphatic polyesters, ‘BIONOLLE’, synthesized by polycondensation reaction  

Microsoft Academic Search

Biodegradable aliphatic polyesters, trademarked ‘BIONOLLE’, such as polybutylene succinate (#1000 series), polybutylene succinate adipate copolymer (#3000 series) and polyethylene succinate (tentatively #6000 series) with high molecular weights ranging from several tens of thousands to several hundreds of thousands were invented in 1990 and produced successfully through polycondensation reaction of glycols with aliphatic dicar?ylic acids and others. A pilot plant with

Takashi Fujimaki

1998-01-01

317

Processing, performance and biodegradability of a thermoplastic aliphatic polyester\\/starch system  

Microsoft Academic Search

Composites of a biodegradable thermoplastic aliphatic polyester, polybutylene succinate adipate (PBSA), with granular corn starch were investigated for processability, mechanical and thermal properties, and biodegradability. The PBSA\\/starch films were prepared with starch contents of 5%–30% by weight and processed by blown film extrusion. Increasing the starch content led to an increase in modulus and decreases in tensile strength, elongation to

Jo Ann Ratto; Peter J. Stenhouse; Margaret Auerbach; John Mitchell; Richard Farrell

1999-01-01

318

Tailoring the Properties of Thermoplastic Polyester to Meet Special Market Needs  

Microsoft Academic Search

Thermoplastic polyester (PBT) is one of the newest and fastest growing engineering plastics. Introduced in 1969, sales of the resin rose sharply within the first few years as it found utility in various high volume automotive applications such as louvers, body appliques, and high energy ignition components as well as in various electrical and other industry applications. Unlike most new

Carl Gottfried

1983-01-01

319

An atomic force microscopy study of weathering of polyester\\/melamine paint surfaces  

Microsoft Academic Search

The use of an atomic force microscope (AFM) for rapid assessment of the durability of exterior polyester\\/melamine paints has been investigated. The study established an AFM imaging technique that produces data representative of weathering rates of paint films under a range of weathering regimes of varying severity. The effect of scan size on the average roughness parameter was investigated, leading

Simon Biggs; Christopher A Lukey; Geoffrey M Spinks; Siu-Tung Yau

2001-01-01

320

SURFACE GRAFTING OF POLYESTERS ONTO ORGANIC PIGMENTS AND THEIR DISPERSIBILITY IN ORGANIC SOLVENT  

Microsoft Academic Search

To modify the dispersibility of an organic pigment, such as quinacridone and anthraquinone, in organic solvents, the surface grafting of polyesters onto organic pigments by the anionic ring-opening alternating copolymerization of epoxides with cyclic acid anhydrides initiated by potassium carboxylate (COOK) groups introduced onto these surfaces was investigated. The organic pigment having COOK groups was prepared by the following two

NORIO TSUBOKAWA; MASATO KOBAYASHI; TOMOAKI OGASAWARA

1999-01-01

321

Approach to Formation of Multifunctional Polyester Particles in Controlled Nanoscopic Dimensions  

E-print Network

acid) (PLLA), poly(glycolic acid) (PGA), poly( -caprolactone) (PCL), and their copolymers, have properties and control in preparation. Introduction Degradable aliphatic polyester materials, such as poly(L-lactic is primarily influenced by the degree of the epoxide entity implemented in the precursor polymers

Harth, Eva M.

322

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

Microsoft Academic Search

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

M. R. Piggott; B. Harris

1980-01-01

323

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

Microsoft Academic Search

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

T. Hanemann

2006-01-01

324

Use of maleated castor oil as biomodifier in unsaturated polyester resin\\/fly ash composites  

Microsoft Academic Search

Maleated castor oil (MACO) was prepared and was used as biomodifier in unsaturated polyester resin (UPE)\\/fly ash composites. The prepared MACO was characterized for its molecular weight and viscosity. MACO was blended with UPE in three different ratios like 5, 10 and 15wt%. Fly ash was incorporated in the blend matrix (10wt%) and curing was done by free radical polymerization.

Subhankar Ghorui; N. R. Bandyopadhyay; Dipa Ray; Suparna Sengupta; Tanusree Kar

2011-01-01

325

3D printing of new biobased unsaturated polyesters by microstereo-thermallithography.  

PubMed

New micro three-dimensional (3D) scaffolds using biobased unsaturated polyesters (UPs) were prepared by microstereo-thermal-lithography (?STLG). This advanced processing technique offers indubitable advantages over traditional printing methods. The accuracy and roughness of the 3D structures were evaluated by scanning electron microscopy and infinite focus microscopy, revealing a suitable roughness for cell attachment. UPs were synthesized by bulk polycondensation between biobased aliphatic diacids (succinic, adipic and sebacic acid) and two different glycols (propylene glycol and diethylene glycol) using fumaric acid as the source of double bonds. The chemical structures of the new oligomers were confirmed by proton nuclear magnetic resonance spectra, attenuated total reflectance Fourier transform infrared spectroscopy and matrix assisted laser desorption/ionization-time of flight mass spectrometry. The thermal and mechanical properties of the UPs were evaluated to determine the influence of the diacid/glycol ratio and the type of diacid in the polyester's properties. In addition an extensive thermal characterization of the polyesters is reported. The data presented in this work opens the possibility for the use of biobased polyesters in additive manufacturing technologies as a route to prepare biodegradable tailor made scaffolds that have potential applications in a tissue engineering area. PMID:25190707

Gonçalves, Filipa A M M; Costa, Cátia S M F; Fabela, Inês G P; Farinha, Dina; Faneca, Henrique; Simões, Pedro N; Serra, Arménio C; Bártolo, Paulo J; Coelho, Jorge F J

2014-09-01

326

Atomic force microscopy, a powerful tool to study blend morphologies based on polyester resins  

Microsoft Academic Search

Atomic Force Microscopy (AFM) was an unusual but effective tool used to investigate the morphology of cured blends based on UP (unsaturated polyester). The pertinence of AFM was evaluated by studying four miscible UP\\/LPA (low profile additive)\\/ST (styrene) blend systems. The morphology of these cured blends before and after LPA solubilization was analogous in SEM (Scanning Electron Microscopy) and AFM.

C. Serré; M. Vayer; R. Erre; N. Boyard; C. Ollive

2001-01-01

327

Design and applications of biodegradable polyester tissue scaffolds based on endogenous monomers found in human metabolism.  

PubMed

Synthetic polyesters have deeply impacted various biomedical and engineering fields, such as tissue scaffolding and therapeutic delivery. Currently, many applications involving polyesters are being explored with polymers derived from monomers that are endogenous to the human metabolism. Examples of these monomers include glycerol, xylitol, sorbitol, and lactic, sebacic, citric, succinic, alpha-ketoglutaric, and fumaric acids. In terms of mechanical versatility, crystallinity, hydrophobicity, and biocompatibility, polyesters synthesized partially or completely from these monomers can display a wide range of properties. The flexibility in these macromolecular properties allows for materials to be tailored according to the needs of a particular application. Along with the presence of natural monomers that allows for a high probability of biocompatibility, there is also an added benefit that this class of polyesters is more environmentally friendly than many other materials used in biomedical engineering. While the selection of monomers may be limited by nature, these polymers have produced or have the potential to produce an enormous number of successes in vitro and in vivo. PMID:19924045

Barrett, Devin G; Yousaf, Muhammad N

2009-01-01

328

Fabrication Technology  

SciTech Connect

The mission of the Fabrication Technology thrust area is to have an adequate base of manufacturing technology, not necessarily resident at Lawrence Livermore National Laboratory (LLNL), to conduct the future business of LLNL. The specific goals continue to be to (1) develop an understanding of fundamental fabrication processes; (2) construct general purpose process models that will have wide applicability; (3) document findings and models in journals; (4) transfer technology to LLNL programs, industry, and colleagues; and (5) develop continuing relationships with the industrial and academic communities to advance the collective understanding of fabrication processes. The strategy to ensure success is changing. For technologies in which they are expert and which will continue to be of future importance to LLNL, they can often attract outside resources both to maintain their expertise by applying it to a specific problem and to help fund further development. A popular vehicle to fund such work is the Cooperative Research and Development Agreement with industry. For technologies needing development because of their future critical importance and in which they are not expert, they use internal funding sources. These latter are the topics of the thrust area. Three FY-92 funded projects are discussed in this section. Each project clearly moves the Fabrication Technology thrust area towards the goals outlined above. They have also continued their membership in the North Carolina State University Precision Engineering Center, a multidisciplinary research and graduate program established to provide the new technologies needed by high-technology institutions in the US. As members, they have access to and use of the results of their research projects, many of which parallel the precision engineering efforts at LLNL.

Blaedel, K.L.

1993-03-01

329

Electron-beam modification of textile fabrics for hydrophilic finishing  

NASA Astrophysics Data System (ADS)

A study has been made to modify different textile fabrics such as cotton, cotton/polyester blend and nylon-6 fabrics by surface coating with a constant thickness layer of 25 ?m of aqueous solution of polyvinyl alcohol (PVA) and acrylic acid (AAc). Radiation curing of surface coating was accomplished by electron beam irradiation with a constant dose of 50 kGy. Parameters affecting hydrophilicity of cured coated fabrics, namely, presence or absence of cross-linking agent and concentration of AAc in coating solution, were investigated. Properties affiliated with hydrophilicity, specifically water uptake and weight loss, before and after several washing cycles were followed up. Crease recovery angle was determined. Considerable enhancement, in water uptake as well as crease recovery angle, has been attained with increasing AAc content in solution in case of nylon-6, followed by blends and then cotton. Moreover, dyeing properties for coated fabrics, with solution containing 4 wt.% AAc, has been tested by color difference method, for basic and reactive dyes. Relative increase in color strength has been achieved. The presence of cross-linking agent in coating solution played a significant role, specifically in case of dyeing properties. Morphology of coated fabrics was examined by scanning electron microscope (SEM), which indicated fastness and compatibility between coating and fabrics. Correlation between structure and obtained results was given.

Ibrahim, Mervat S.; Salmawi, Kariman M. El; Ibrahim, Sayeda M.

2005-03-01

330

Toner and paper-based fabrication techniques for microfluidic applications.  

PubMed

The interest in low-cost microfluidic platforms as well as emerging microfabrication techniques has increased considerably over the last years. Toner- and paper-based techniques have appeared as two of the most promising platforms for the production of disposable devices for on-chip applications. This review focuses on recent advances in the fabrication techniques and in the analytical/bioanalytical applications of toner and paper-based devices. The discussion is divided in two parts dealing with (i) toner and (ii) paper devices. Examples of miniaturized devices fabricated by using direct-printing or toner transfer masking in polyester-toner, glass, PDMS as well as conductive platforms as recordable compact disks and printed circuit board are presented. The construction and the use of paper-based devices for off-site diagnosis and bioassays are also described to cover this emerging platform for low-cost diagnostics. PMID:20665911

Coltro, Wendell Karlos Tomazelli; de Jesus, Dosil Pereira; da Silva, José Alberto Fracassi; do Lago, Claudimir Lucio; Carrilho, Emanuel

2010-08-01

331

Multiplex lateral-flow test strips fabricated by two-dimensional shaping.  

PubMed

We have fabricated paper- and nitrocellulose-based lateral-flow devices that are shaped in two dimensions by a computer-controlled knife. The resulting star, candelabra, and other structures are spotted with multiple bioassay reagents to produce multiplex lateral-flow assays. We have also fabricated laminar composites in which porous nitrocellulose media are sandwiched between vinyl and polyester plastic films. This minimizes evaporation, protects assay surfaces from contamination and dehydration, and eliminates the need for the conventional hard plastic cassette holders that are typically used to package commercial lateral-flow diagnostic strips. The reported fabrication method is novel, low-cost, and well-suited to (i) fabrication and adoption in resource-poor areas, (ii) prototype development, (iii) high-volume manufacturing, and (iii) improving rates of operator error. PMID:20355763

Fenton, Erin M; Mascarenas, Monica R; López, Gabriel P; Sibbett, Scott S

2009-01-01

332

Screen printing of a capacitive cantilever-based motion sensor on fabric using a novel sacrificial layer process for smart fabric applications  

NASA Astrophysics Data System (ADS)

Free-standing cantilevers have been fabricated by screen printing sacrificial and structural layers onto a standard polyester cotton fabric. By printing additional conductive layers, a complete capacitive motion sensor on fabric using only screen printing has been fabricated. This type of free-standing structure cannot currently be fabricated using conventional fabric manufacturing processes. In addition, compared to conventional smart fabric fabrication processes (e.g. weaving and knitting), screen printing offers the advantages of geometric design flexibility and the ability to simultaneously print multiple devices of the same or different designs. Furthermore, a range of active inks exists from the printed electronics industry which can potentially be applied to create many types of smart fabric. Four cantilevers with different lengths have been printed on fabric using a five-layer structure with a sacrificial material underneath the cantilever. The sacrificial layer is subsequently removed at 160 °C for 30 min to achieve a freestanding cantilever above the fabric. Two silver electrodes, one on top of the cantilever and the other on top of the fabric, are used to capacitively detect the movement of the cantilever. In this way, an entirely printed motion sensor is produced on a standard fabric. The motion sensor was initially tested on an electromechanical shaker rig at a low frequency range to examine the linearity and the sensitivity of each design. Then, these sensors were individually attached to a moving human forearm to evaluate more representative results. A commercial accelerometer (Microstrain G-link) was mounted alongside for comparison. The printed sensors have a similar motion response to the commercial accelerometer, demonstrating the potential of a printed smart fabric motion sensor for use in intelligent clothing applications.

Wei, Yang; Torah, Russel; Yang, Kai; Beeby, Steve; Tudor, John

2013-07-01

333

A Pseudomonas strain accumulating polyesters of 3-hydroxybutyric acid and medium-chain-length 3-hydroxyalkanoic acids  

Microsoft Academic Search

Summary A citronellol-utilizing bacterium was isolated that accumulated a polyester consisting of 3-hydroxybutyric acid (3HB) and of medium-chain-length 3-hydroxyalkanoic acids (3HAMCL) from various carbon sources up to approximately 70% of the cellular dry matter if the cells were cultivated in ammineral salts medium under nitrogen limitation. In octanoate-grown cells, for instance, the polyester consisted of 87.5 mol% 3HB and 12.5

Alexander Steinbiichel; Stefan Wiese

1992-01-01

334

Polyesters of 2Pyrone4,6-dicarboxylic Acid (PDC) as Bio-based Plastics Exhibiting Strong Adhering Properties  

Microsoft Academic Search

2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable metabolic intermediate of lignin, its bis(hydroxyethyl) derivative (BHPDC) and bis(hydroxyethyl) terephthalate (BHT) were polymerized to prepare the corresponding polyesters carrying the oxyethyleneoxycarbonyl(2-pyrone-4,6-diyl)carbonyl and oxyethyleneoxy-terephthaloyl units [x and y units, resp., x + y = 1] by polycondensation eliminating water and\\/or 1,2-ethanediol molecules. The polyesters were mostly stable up to 210 °C, after that the

Masakiyo Hishida; Kazuhiro Shikinaka; Yoshihiro Katayama; Shinya Kajita; Eiji Masai; Masaya Nakamura; Yuichiro Otsuka; Seiji Ohara; Kiyotaka Shigehara

2009-01-01

335

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

PubMed

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

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

2013-04-15

336

A novel explanation of a low-profile mechanism for unsaturated polyester resins using phase diagrams  

SciTech Connect

A novel explanation for the mechanism of low profile additives in unsaturated polyester resins by using a concept of a phase diagram was proposed. According to the ternary phase diagrams for the systems of styrene-unsaturated polyester prepolymer-additives (e.g., polyvinyl acetate, polyurethane), the phenomenon of phase separation was explained. Furthermore, the final morphology of cured resins was correlated to the phase diagram. Microscopic observations showed the morphology was controlled by the phase separation. TEM results also clearly showed that the microvoids were formed in the low profile phase, separated from the resin phase, instead of being in the interfacial region as previously reported. It was concluded that a well controlled phase diagram can lead to a shrinkage-controlled low profile system.

Suspene, L.; Fourquier, D.; Yang, Y.S. (Norsolor Orken Group, Verneuil (FRA))

1990-04-01

337

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

SciTech Connect

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.

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

1995-12-31

338

Correlation between mechanical and dielectric properties of Alfa/Wool/Polymeric hybrid fibres reinforced polyester composites  

NASA Astrophysics Data System (ADS)

Dielectric measurements and tensile testing of polyester/natural fibres (Alfa/wool) and thermo binder fibres (Pe/Pet) composites were investigated in order to study the adhesion of the fibres in the polyester matrix. Two composites #1 and #2 having 17:1:2 and 17:2:1 as a relative fraction of alfa/wool and thermo binder (Pe/Pet), respectively, have been characterized in this study. The obtained results revealed that the fibres adhesion in the matrix was better in the composite #1 than in the composite #2. Indeed, the analysis of the interfacial or Maxwell-Wagner-Sillars (MWS) polarization intensity, using the Havriliak-Negami model, has shown a lower intensity and the tensile testing exhibited a higher Young modulus in the composite #1. So the thermo binder fibres improve this adhesion.

Triki, A.; Omri, M. A.; Guicha, M.; Ben Hassen, M.; Arous, M.; Kallel, A.

2013-12-01

339

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

PubMed Central

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

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

2014-01-01

340

Synthesis of lipase-catalysed silicone-polyesters and silicone-polyamides at elevated temperatures.  

PubMed

More and more enzymes are being explored as alternatives to conventional catalysts in chemical reactions. To utilize these biocatalysts to their fullest, it is incumbent on researchers to gain a complete understanding of the reaction conditions that particular enzymes will tolerate. To this end siloxane-containing polyesters and polyamides have been produced via N435-mediated catalysis at temperatures well above the normal denaturation temperature for free CalB. Low molecular weight disiloxane-based acceptors release the enzyme from its acylated state with equal proficiency while longer chain siloxanes favours polyester synthesis. The thermal tolerance of the enzyme catalyst is increased using longer chain diesters and generally more hydrophobic substrates. PMID:23999945

Frampton, Mark B; Zelisko, Paul M

2013-10-18

341

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

PubMed

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

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

2014-01-01

342

Improving the miscibility of biodegradable polyester/polyphosphazene blends using cross-linkable polyphosphazene.  

PubMed

Biodegradable polyesters and polyphosphazenes are both promising biomaterials for tissue regeneration. A combination of both materials would provide additional advantages over the individual components in aspects of biocompatibility and osteocompatibility. Applications of polyester/polyphosphazene composites, however, were limited due to the severe phase separation. In this study, cross-linkable poly(glycine ethyl ester-co-hydroxyethyl methacrylate)phosphazene (PGHP) was synthesized. It was blended with poly(L-lactide) (PLLA) or poly(L-lactide-co-glycolide) (PLGA), using chloroform as a mutual solvent, and photo-crosslinked before solvent removal. The resulting PLLA (or PLGA)/PGHP composites demonstrated no significant phase separation due to the restricting function of the crosslinked PGHP polymeric network. In comparison with uncrosslinked blends, the mechanical properties of crosslinked composites were remarkably improved, which indicated their strong potential in bone regeneration applications. PMID:25426734

Shan, Dingying; Huang, Zhaohui; Zhao, Yuchen; Cai, Qing; Yang, Xiaoping

2014-12-01

343

Studies on Tensile Properties of Eri Silk/Polyester Blended Yarn Using Design of Experiment Methodology  

NASA Astrophysics Data System (ADS)

Eri silk is one of the four varieties of silk available in India which has excellent thermal insulation property. With a view to explore its blending possibilities with polyester, manufacturing of eri/polyester blended yarn at different blend ratio in ring spinning system has been successfully performed following drawframe blending technique. The Box and Behnken design of experiment for three variables and three levels has been used to study the influence of count of the yarn spun (Ne), twist multiplier and proportion of eri fibre in the blends on some important tensile properties of the yarns produced. The chosen level of variables remaining within the industrially acceptable limits shows that fibre character and yarn parameters are the determining factors to influence yarn tensile properties. Validity of Hamburger model for the prediction of blended yarn tenacity has also been assessed for the blended yarn produced.

Choudhuri, Prabir Kumar; Majumdar, Prabal Kumar; Sarkar, Bijon

2013-03-01

344

Synthesis and biocompatibility properties of polyester containing various diacid based on isosorbide.  

PubMed

Biocompatible polyesters were prepared from isosorbide, various aliphatic diacid via a simple non-solvent polycondensation with a low toxicity catalyst. The successful synthesis of the polyesters was confirmed by gel permeation chromatography, (1)H-nuclear magnetic resonance and Fourier transform infrared spectroscopes, and differential scanning calorimetry. The degradation tests were performed at 37°C in phosphate buffer solution (approximately pH 7.3). The in vitro cytocompatibility test results following culture of osteoblasts on the polymer surface showed that relative cell number on poly(isosorbide sebacate) and poly(isosorbide adipate) films after 5 days of culture on polymer films proliferated at least as well as those on a culture plate. PMID:22573717

Park, Hyung-Seok; Gong, Myoung-Seon; Knowles, Jonathan C

2012-07-01

345

Non-contact laser sealing of thin polyester food packaging films  

NASA Astrophysics Data System (ADS)

We describe a laser-based, non-contact sealing technique for thin, polyester-based lidding films, used in PET containers for food packaging. The method uses a beam-steered laser to seal the container, thereby enabling virtually instant changeover from one product line to another. Unlike conventional sealing PET film processes, no bespoke tooling is required to hold the package components in close proximity and under pressure whilst the seal is formed. This greatly reduces sealing machine tooling costs and potential downtime at product changeovers. Results are presented that show that the process is able to produce seals of higher strength using thin (26 ?m) polyester film than those from the conventional thermal/mechanical process. This provides a potential for increased production flexibility, reduction in product wastage, and for reducing the cost and embodied energy in construction of a less massive sealing machine.

Brown, Neil; Kerr, David; Parkin, Robert M.; Jackson, Michael R.; Shi, Fangmin

2012-10-01

346

Chemical resistance/thermal and mechanical properties of unsaturated polyester-based nanocomposites  

NASA Astrophysics Data System (ADS)

Nanocomposites were synthesized using unsaturated polyester as the matrix and organically modified montmorillonite (CA-MMT) as the reinforcing agent. XRD pattern of the modified montmorillonite showed that the interlayer spacing expanded from 1.21 to 1.9 nm, indicating intercalation. TGA and DTA show loss of organic surfactant from interlayer galleries. Glass transition temperature (T g) of these composites increased from 71 °C in the unfilled unsaturated polyester to 79 °C in the composites with 5 % organically modified montmorillonite. Chemical resistance and mechanical properties of the UP/organo-clay nanocomposites were studied. Chemical resistance was studied under aqueous conditions in acetic acid, nitric acid, hydrochloric acid, sodium hydroxide, aqueous ammonia and sodium carbonate. Chemical resistance studies reveal maximum weight gain/loss with increasing clay content. Mechanical studies show maximum characteristics for the composites-clay filled 5 % (w/w).

Jaya Vinse Ruban, Y.; Ginil Mon, S.; Vetha Roy, D.

2013-01-01

347

Synthesis of elastic biodegradable polyesters of ethylene glycol and butylene glycol from sebacic acid.  

PubMed

High molecular weight biodegradable polyesters were prepared from sebacic acid, ethylene glycol and butylene glycol through a simple non-solvent polycondensation with a low toxicity catalyst. The successful synthesis of the polyesters was confirmed by gel permeation chromatography, (1)H-nuclear magnetic resonance and Fourier transform-infrared spectroscopies and differential scanning calorimetry. The degradation tests were performed at 37 °C in phosphate buffer solution (pH 7.4) and showed a mass loss of ~5% over 12 weeks compared with only 2% for polycaprolactone (PCL). Reverse transcription polymerase chain reaction results following culture of osteoblasts on the polymer surface showed that poly(ethylene sebacate) and poly(butylene sebacate) films were optimal for osteoblast formation in terms of Runx 2 and osteocalcin gene expression. PMID:22522011

Park, Hyung-seok; Seo, Jung-a; Lee, Hye-Young; Kim, Hae-Won; Wall, Ivan B; Gong, Myoung-Seon; Knowles, Jonathan C

2012-08-01

348

Room temperature organocatalyzed reductive depolymerization of waste polyethers, polyesters, and polycarbonates.  

PubMed

The reductive depolymerization of a variety of polymeric materials based on polyethers, polyesters, and polycarbonates is described using hydrosilanes as reductants and metal-free catalysts. This strategy enables the selective depolymerization of waste polymers as well as bio-based polyesters to functional chemicals such as alcohols and phenols at room temperature. Commercially available B(C6 F5 )3 and [Ph3 C(+) ,B(C6 F5 )4 (-) ] catalysts are active hydrosilylation catalysts in this procedure and they are compatible with the use of inexpensive and air-stable polymethylhydrosiloxane and tetramethyldisiloxane as reductants. A significant advantage of this recycling method is derived from its tolerance to the additives present in waste plastics and its ability to selectively depolymerize mixtures of polymers. PMID:25706036

Feghali, Elias; Cantat, Thibault

2015-03-01

349

Liquid Crystal Polymers. XI. Liquid Crystal Aromatic Polyesters: Early History and Future Trends  

Microsoft Academic Search

This brief history and review of liquid crystalline polyesters (LCPs) is limited to all-aromatic LCPs except for a description of the discovery of the first thermotropic polymer to be injection molded or melt spun and characterized as being liquid crystalline: an Eastman PET\\/PHB (p-hydroxybenzoic acid) copolyester (first reported as being liquid crystalline in 1974). In the same year a Carborundum

W. J. Jackson Jr

1989-01-01

350

Hamstring graft motion in the femoral bone tunnel when using titanium button\\/ polyester tape fixation  

Microsoft Academic Search

The objective of this study was to determine the relative motion of a quadruple hamstring graft within the femoral bone tunnel\\u000a (graft-tunnel motion) under tensile loading. Six graft constructs were prepared from the semitendinosus and gracilis tendons\\u000a of human cadavers and were fixed with a titanium button and polyester tape within a bone tunnel in a cadaveric femur. Three\\u000a different

Jürgen Höher; Glen A. Livesay; C. Benjamin Ma; John D. Withrow; Freddie H. Fu; S. L. Y. Woo

1999-01-01

351

Test procedures for polyester immobilized salt-containing surrogate mixed wastes  

SciTech Connect

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.

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

1997-07-18

352

Hygrothermal response of polymer composites based on modified sisal fibers and unsaturated polyester resin  

SciTech Connect

Polymer composites made from surface modified sisal fibers and unsaturated polyester resin were exposed to different wet environments and their physico-mechanical properties were evaluated as a function of exposure time. It was found that all types of treatments improved the performance of composites. Silane treated fiber composites displayed superior strength retention property under humid environments, while zirconate treated fiber composites resulted fairly better in immersed water condition.

Singh, B.; Gupta, M. [Central Building Research Inst., Roorkee (India)

1995-10-01

353

Volume change in the cure of low profile unsaturated polyester resins  

SciTech Connect

Interactions of reaction, gelation, microstructure formation and volume changes were studied for an unsaturated polyester resin with and without low profile additives. A dilatometer was designed and built to monitor the volume change. Differential scanning calorimetry (DSC) was used to estimate the conversion in the dilatometer, while SEM and TEM were used to follow microstructure formation and a rheometer was used to follow resin gelation. A conceptual model was presented to explain the results.

Kinkelaar, M.; Hsu, C.P.; Lee, L.J. (Ohio State University, Columbus (USA))

1990-07-01

354

Microstructure, tensile properties, and biodegradability of aliphatic polyester\\/clay nanocomposites  

Microsoft Academic Search

Novel biodegradable aliphatic polyester (APES)\\/organoclay nanocomposites were prepared through melt intercalation method. Two kinds of organoclays, Cloisite 30B and Cloisite 10A with different ammonium cations located in the silicate gallery, were chosen for the nanocomposites preparation. The dispersion of the silicate layers in the APES hybrids was characterized by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tensile properties

Sang-Rock Lee; Hwan-Man Park; Hyuntaek Lim; Taekyu Kang; Xiucuo Li; Won-Jei Cho; Chang-Sik Ha

2002-01-01

355

Three-body abrasive wear of short glass fibre polyester composite  

Microsoft Academic Search

Short E-glass fibre-reinforced polyester composites with and without filler have been studied for the low stress abrasive wear behaviour carried out using Rubber Wheel Abrasion Test (RWAT) apparatus. In the present investigation, angular silica sand particles of size ranging between 100–200 and 200–300 ?m were used as dry and loose abrasives. The volume loss of the composite during three-body abrasion

Navin Chand; Ajay Naik; Somit Neogi

2000-01-01

356

Post-fire mechanical properties of glass-reinforced polyester composites  

Microsoft Academic Search

An investigation into changes in the mechanical properties of glass-reinforced polyester composites after exposure to intense radiant heat is presented. The tension, compression, flexure and interlaminar shear properties fell rapidly with increasing heat flux and heat-exposure time owing, mainly, to charring and delamination cracking caused by burning of the composite. Substantially higher post-fire mechanical properties were attained when the composite

A. P. Mouritz; Z. Mathys

2001-01-01

357

Polyether–polyester diblock copolymers for the preparation of paclitaxel loaded polymeric micelle formulations  

Microsoft Academic Search

A number of hypersensitivity reactions have been attributed to the presence of Cremophor® EL in the current formulation for paclitaxel. This has led to the development of formulations for paclitaxel employing polyether–polyester diblock copolymers as micelle forming carriers. Diblock copolymers of methoxypolyethylene glycol-block-poly(d,l-lactide) (MePEG:PDLLA) were synthesized from monomers of d,l-lactide and MePEG by a ring opening bulk polymerization in the

R. T. Liggins; H. M. Burt

2002-01-01

358

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

Microsoft Academic Search

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

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

2003-01-01

359

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

Microsoft Academic Search

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

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

2012-01-01

360

Reaction kinetics and network characterization of UV-curing polyester acrylate inorganic\\/organic hybrids  

Microsoft Academic Search

Polyester acrylate inorganic\\/organic hybrids were prepared using a sol–gel precursor, coupling agent, and reactive diluent. The hybrids were cured via a UV-free radical initiator. Design of experiments (DOE) was utilized to investigate reaction kinetics and complex variable interactions. The effects of the silicate groups on the free radical photo-curing reaction kinetics were investigated utilizing a time-resolved Fourier transform infrared (FT–IR)

Ahmet Nebioglu; Mark D. Soucek

2007-01-01

361

Optical Phase Conjugation in Polyesters with Cyanoazobenzene Units in the Side Chain  

NASA Astrophysics Data System (ADS)

Efficient optical phase-conjugate (PC) signals in four kinds of novel polyester films containing cyanoazobenzene units in the side chain are reported. One of them can efficiently generate only the photoinduced anisotropy (PA) component of PC signal, while the other three films can simultaneously generate two types of PC signals, PA and holographic components. These polymers have good potential not only as a phase conjugator but also as a polarization-sensitive hologram-recording material.

Nakagawa, Kazuo; Sato, Moriyuki; Mukaida, Kenichi; Fujiwara, Hirofumi

1995-11-01

362

Surface modification of biodegradable polyesters with fatty acid conjugates for improved drug targeting  

Microsoft Academic Search

We describe a general method for incorporating target ligands into the surface of biocompatible polyester poly(lactic-co-glycolic acid) (PLGA) 50\\/50 materials using fatty acids. Avidin-fatty acid conjugates were prepared and efficiently incorporated into PLGA. Avidin was chosen as an adaptor protein to facilitate the attachment of a variety of biotinylated ligands. We show that fatty acid preferentially associates with the hydrophobic

Tarek M. Fahmy; Robert M. Samstein; Casey C. Harness; W. Mark Saltzman

2005-01-01

363

Mechanism of breakdown in the interface region of glass reinforced polyester by artificial weathering  

Microsoft Academic Search

Laboratory studies were conducted to elucidate the mechanism of breakdown in the interface region of glass-fibre reinforced polyester (GRP) composites on outdoor weathering. GRP composites were subjected to the effects of moisture, temperature and radiation. Breakdown in the interface region occurred when the GRP sheets were aged in the presence of water and physically-induced stress (thermally and\\/or by moisture). The

A. Blaga; R. S. Yamasaki

1973-01-01

364

The environmental influence in enzymatic polymerization of aliphatic polyesters in bulk and aqueous mini-emulsion  

Microsoft Academic Search

The catalytic effect of enzymes in different environments has been compared. Biodegradable polyesters and corresponding nanoparticles have been synthesized by an “eco-friendly” technique; enzyme-catalyzed ring-opening polymerization of lactones in bulk and in an aqueous mini-emulsion. Lipases from Burkholderia cepacia (lipase PS), B. cepacia immobilized on ceramic, Pseudomonas fluorescens and Candida Antarctica have been used as catalysts in the polymerization of

Sofia Målberg; Anna Finne-Wistrand; Ann-Christine Albertsson

2010-01-01

365

UV-absorbers in the dyeing of polyester with disperse dyes  

Microsoft Academic Search

The effect of the benzotriazole type UV-absorbers Tinuvin P and Tinuvin 327 and 2.4-dihydroxy benzophenone in the dyeing of polyester fibres with Viosperse Blue RFS, an azodye of low light fastness at various depths of dyeing and UV-absorber amounts was studied using different application procedures. The dye and UV-absorber uptake and the light and sublimation fastness of the dyed samples

E. G. Tsatsaroni; I. C. Eleftheriadis

2004-01-01

366

Direct esterification of a hydroxyl functional polyester resin with p-hydroxybenzoic acid  

Microsoft Academic Search

Comparison of the physical properties of direct esterified, both purified and unpurified, and standard polyester coatings was undertaken. Clear and pigmented baked enamels, both non-cross-linked and cross-linked, were produced. Results indicate that coating binders containing the unpurified direct esterified resin are potentially superior to conventional binders as they exhibit the outstanding feature of being both hard and flexible. This improvement

Stephen G Boyes; Rodney P Chaplin; Thomas P Davis; Jim Viatos; David P Buxton

2000-01-01

367

Polyester-bonded textured composites with single-crystalline shape memory Ni Mn Ga particles  

NASA Astrophysics Data System (ADS)

Single-crystalline Ni 51Mn 27Ga 22 particles with the five-layered martensite structure (5M) were prepared by mortar grinding of annealed melt-extracted fibres. These particles were embedded in a stiffness-matched polyester matrix and textured by an alignment field. With increasing compression stress, the magnetic properties of the composites could be continuously changed. Magnetisation measurements of compressed composites, indirectly indicate stress-induced twin boundary motion in the MSM particles.

Hinz, D.; Scheerbaum, N.; Gutfleisch, O.; Müller, K.-H.; Schultz, L.

2007-03-01

368

The synthesis, characterization and biocompatibility of poly(ester urethane)\\/polyhedral oligomeric silesquioxane nanocomposites  

Microsoft Academic Search

The primary goal of this study is to develop a facile and inexpensive synthesis method for a new biodegradable and biocompatible poly(ester urethane) (PEU)\\/polyhedral oligomeric silesquioxanes (POSS) nanocomposite via in situ homogeneous solution polymerization reaction into prescribed macromolecular structure and properties including improved biocompatibility, thermal and hydrolytic stability, and stiffness and strength. Cell culture studies, nuclear magnetic resonance spectroscopy, X-ray

Wenshou Wang; Yan-lin Guo; Joshua U. Otaigbe

2009-01-01

369

Automatic Sprinkler Protection of Palletized, 55 Gallon Drum Storage of Unsaturated Polyester Resins  

Microsoft Academic Search

Unsaturated polyester resin (UPR) is used extensively in the production of composite plastic materials, such as fiberglass\\u000a products. UPRs are classified by NFPA 30 as Class I flammable liquids, often Class IC, based on their styrene content. However,\\u000a because UPR is a viscous liquid with a low vapor pressure and a high-density, it was postulated that UPR stored in drums

Joseph L. Scheffey; Jeffrey M. Shapiro

2006-01-01

370

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

SciTech Connect

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.

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

1996-12-31

371

A functionalizable polyester with free hydroxyl groups and tunable physiochemical and biological properties  

PubMed Central

Polyesters with free functional groups allow facile modifications with biomolecules, which can lead to versatile biomaterials that afford controlled interactions with cells and tissues. Efficient synthesis of functionalizable polyesters is still a challenge that greatly limits the availability and widespread applications of biofunctionalized synthetic polymers. Here we report a simple route to prepare a functionalizable polyester, poly(sebacoyl diglyceride) (PSeD) bearing free hydroxyl groups. The key synthetic step is an epoxide ring-opening polymerization, instead of the traditional polycondensation, that produces poly(glycerol sebacate) (PGS) [1]. PSeD has a more defined structure with mostly linear backbone, more free hydroxyl groups, higher molecular weight, and lower polydispersity than PGS. Crosslinking PSeD with sebacic acid yields a polymer five times tougher and more elastic than cured PGS. PSeD exhibits good cytocompatibility in vitro. Furthermore, functionalization by glycine proceeds with high efficiency. This versatile synthetic platform can offer a large family of biodegradable, functionalized polymers with tunable physiochemical and biological properties useful for a wide range of biomedical applications. PMID:20149441

You, Zhengwei; Cao, Haiping; Gao, Jin; Shin, Paul H.; Day, Billy W.; Wang, Yadong

2010-01-01

372

Analytical approaches to identify potential migrants in polyester-polyurethane can coatings.  

PubMed

The safety of a polyester-polyurethane can coating has been assessed using a suite of complementary analytical methods to identify and estimate the concentrations of potential chemical migrants. The polyester was based on phthalic acids and aliphatic diols. The polyisocyanate cross-linking agent was 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethyl cyclohexane homopolymer (IPDI) blocked with methylethylketone oxime (MEKO) to make a one-part formulation. The overall migrate, obtained using solvent extraction of cured films, comprised almost completely of 12 cyclic and one linear polyester oligomer up to molecular weight 800 and containing up to six monomer units. These 13 oligomers covered a total of 28 isomeric forms. Other minor components detected were plasticisers and surfactants as well as impurities present in the starting materials. There was no detectable residue of either the blocked isocyanate (<0.01 microg/dm(2)) used as the starting substance or the unblocked isocyanate (<0.02 microg/dm(2)). The level of extractable IPDI was used as an indicator of the completeness of cure in experimental coatings. These studies revealed that there was an influence of time, temperature and catalyst content. Polymerisation was also influenced by the additives used and by the ageing of the wet coating formulation over several months. These studies allow parameters to be specified to ensure that commercial production coatings receive a full cure giving low migration characteristics. PMID:19787516

Louise Bradley, Emma; Driffield, Malcolm; Guthrie, James; Harmer, Nick; Thomas Oldring, Peter Kenneth; Castle, Laurence

2009-12-01

373

Functional characterization and structural modeling of synthetic polyester-degrading hydrolases from Thermomonospora curvata  

PubMed Central

Thermomonospora curvata is a thermophilic actinomycete phylogenetically related to Thermobifida fusca that produces extracellular hydrolases capable of degrading synthetic polyesters. Analysis of the genome of T. curvata DSM43183 revealed two genes coding for putative polyester hydrolases Tcur1278 and Tcur0390 sharing 61% sequence identity with the T. fusca enzymes. Mature proteins of Tcur1278 and Tcur0390 were cloned and expressed in Escherichia coli TOP10. Tcur1278 and Tcur0390 exhibited an optimal reaction temperature against p-nitrophenyl butyrate at 60°C and 55°C, respectively. The optimal pH for both enzymes was determined at pH 8.5. Tcur1278 retained more than 80% and Tcur0390 less than 10% of their initial activity following incubation for 60 min at 55°C. Tcur0390 showed a higher hydrolytic activity against poly(?-caprolactone) and polyethylene terephthalate (PET) nanoparticles compared to Tcur1278 at reaction temperatures up to 50°C. At 55°C and 60°C, hydrolytic activity against PET nanoparticles was only detected with Tcur1278. In silico modeling of the polyester hydrolases and docking with a model substrate composed of two repeating units of PET revealed the typical fold of ?/? serine hydrolases with an exposed catalytic triad. Molecular dynamics simulations confirmed the superior thermal stability of Tcur1278 considered as the main reason for its higher hydrolytic activity on PET. PMID:25405080

2014-01-01

374

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

PubMed

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

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

375

Synthesis and modification of defined plurifunctional chiral and racemic polyethers and polyesters  

SciTech Connect

Chiral and racemic polyethers and polyesters with reactive groups in the side-chain were synthesized by ring-opening polymerization and polycondensation. Plurifunctional polyethers are obtained by polymerizing the corresponding oxiranes bearing (-CH{sub 2}-){sub n}X, as side chain group with X = Cl, Br, OH. From these polymers liquid crystal materials are obtained by chemical modification reaction with 4-cyano-4`-hydroxy-biphenyl mesogenic group. The thermal properties are depending on the degree of substitution. Modified crystalline cyclic tetramer of epichlorohydrin developed also liquid crystalline properties close to that of the linear polymer. Cholesteric materials were obtained by polymerization of the chiral oxirane bearing the same mesogenic group in the substituent. Other structural materials can be obtained by copolymerization reactions. Polyesters with chirality in the main chain and bearing hydroxyl functional groups were prepared by polycondensation of potassium salts of (S)-malic and (R,R) tartaric acids with dibromo derivatives. These polyesters are used as carriers of biologically active agents.

Le Borgne, A.; Taton, D.; Sepulchre, M.; Spassky, N. [Universite Pierre et Marie Curie, Paris (France)

1993-12-31

376

A functionalizable polyester with free hydroxyl groups and tunable physiochemical and biological properties.  

PubMed

Polyesters with free functional groups allow facile modifications with biomolecules, which can lead to versatile biomaterials that afford controlled interactions with cells and tissues. Efficient synthesis of functionalizable polyesters (Functionalizable polymer is defined as a polymer with functional groups that readily react with biomolecules and functionalized biomaterial as one already modified with biomolecules.) is still a challenge that greatly limits the availability and widespread applications of biofunctionalized synthetic polymers. Here we report a simple route to prepare a functionalizable polyester, poly(sebacoyl diglyceride) (PSeD) bearing free hydroxyl groups. The key synthetic step is an epoxide ring-opening polymerization, instead of the traditional polycondensation that produces poly(glycerol sebacate) (PGS) (Wang YD, Ameer GA, Sheppard BJ, Langer R. A tough biodegradable elastomer. Nat Biotechnol 2002;20(6):602-6). PSeD has a more defined structure with mostly linear backbone, more free hydroxyl groups, higher molecular weight, and lower polydispersity than PGS. Crosslinking PSeD with sebacic acid yields a polymer five times tougher and more elastic than cured PGS. PSeD exhibits good cytocompatibility in vitro. Furthermore, functionalization by glycine proceeds with high efficiency. This versatile synthetic platform can offer a large family of biodegradable, functionalized polymers with tunable physiochemical and biological properties useful for a wide range of biomedical applications. PMID:20149441

You, Zhengwei; Cao, Haiping; Gao, Jin; Shin, Paul H; Day, Billy W; Wang, Yadong

2010-04-01

377

Self-cleaning and self-sanitizing coatings on plastic fabrics: design, manufacture and performance.  

PubMed

Self-cleaning and self-sanitizing coatings are of utmost interest in several manufacturing domains. In particular, fabrics and textile materials are often pre-treated by impregnation or incorporation with antimicrobial pesticides for protection purposes against bacteria and fungi that are pathogenic for man or other animals. In this respect, the present investigation deals with the design and manufacture of self-cleaning and self-sanitizing coatings on plastic fabrics. The functionalization of the coatings was yield by incorporating active inorganic matter alone (i.e., photo-catalytic TiO2 anatase and Ag(+) ions) inside an organic inorganic hybrid binder. The achieved formulations were deposited on coextruded polyvinylchloride-polyester fabrics by air-mix spraying and left to dry at ambient temperature. The performance of the resulting coatings were characterized for their self-cleaning and self-sanitizing ability according to standardized testing procedure and/or applicable international regulations. PMID:24892563

Barletta, M; Vesco, S; Tagliaferri, V

2014-08-01

378

A high-performance dielectric elastomer consisting of bio-based polyester elastomer and titanium dioxide powder  

NASA Astrophysics Data System (ADS)

A bio-based polyester elastomer containing many polar groups was combined with high-dielectric-constant titanium dioxide (TiO2) powder to form a dielectric elastomer composite for the first time. The effects of the titanium dioxide filler on the elastic modulus, dielectric properties, and electromechanical responses of the polyester dielectric elastomer were studied. We found that the dielectric constant of composites increased with increasing content of TiO2. Nevertheless, the elastic modulus of the composites did not increase with increasing content of TiO2, and the polyester elastomer filled with 6 vol. % of TiO2 exhibited the lowest elastic modulus, which led to a high prestrain-free actuated strain of 11.8% at a low electric field of just 9.8 kV/mm. The actuated strain is better than other dielectric elastomers reported in the literature. The high electromechanical performance was attributed to the increase in dielectric constant and decrease in elastic modulus of the composite from those of the pure polyester elastomer. The decrease in elastic modulus was explained in detail by the competing effects of crosslink density and filler network. In addition, a dramatic increase in dielectric constant of the composite was observed and discussed through several dielectric mixing rules. Finally, the polyester elastomer and titanium dioxide are both environment-friendly, making possible the composite to be used in biological and medical devices.

Yang, Dan; Tian, Ming; Dong, Yingchao; Kang, Hailan; Gong, Daolin; Zhang, Liqun

2013-10-01

379

Parenteral protein delivery systems using biodegradable polyesters of ABA block structure, containing hydrophobic poly(lactide-co-glycolide) A blocks and hydrophilic poly(ethylene oxide) B blocks  

Microsoft Academic Search

Parenteral delivery systems for proteins, based on biodegradable polyesters present significant problems with respect to modulation of release properties. Frequently proteins are more sensitive to environmental factors than peptides, leading to a loss in biological activity. We have investigated the release properties of ABA block copolymers, which contain hydrophilic poly(ethylene oxide) B blocks. Microspheres prepared from these biodegradable polyesters show

T. Kissel; Y. X. Li; C. Volland; S. Görich; R. Koneberg

1996-01-01

380

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

PubMed

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

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

2013-08-01

381

Flame retardancy and UV protection of cotton based fabrics using nano ZnO and polycarboxylic acids.  

PubMed

This research mainly deals with a novel flame-retardant and UV-protection for cellulosic fabrics using ZnO nanoparticles. We present the preparation and application of ZnO nanoparticles. The size of the prepared nanoparticles was analysed using dynamic light scattering (DLS). The application of nano ZnO on cellulosic fabrics (cotton 100% and cotton/cotton polyester 65/35%) was achieved by using different polycarboxilic acids (succinic acid [SA] and 1,2,3,4-butane tetracarboxilic acids [BTCA]) with sodium hypophosphite (SHP) as catalyst through conventional pad-dry-cure method. The effect of concentration of SHP on the physical properties, flammability and UV-protection of cross-linked fabrics are investigated. The effect of concentration of zinc oxide nanoparticles and the effect of curing temperature were also investigated. The results revealed the importance of SHP in increasing the flame-redundancy of the treated cellulosic fabrics. PMID:23218312

El-Hady, M M Abd; Farouk, A; Sharaf, S

2013-01-30

382

Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amide)s  

PubMed Central

Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and ?-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed. PMID:24776758

Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

2014-01-01

383

Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.  

PubMed

Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and ?-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed. PMID:24776758

Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

2014-01-01

384

Compare Fabric Materials  

NSDL National Science Digital Library

Students examine different types of fabric and their characteristics. Using magnifying glasses and sandpaper, they test and observe the weave and wear quality of fabric samples. By comparing the qualities of different fabrics they come to understand why so many different types of fabric exist and are able to recognize or suggest different uses for them.

Center for Engineering Educational Outreach,

385

Polymorphous computing fabric  

DOEpatents

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.

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

2011-01-18

386

Structural and Functional Studies of Aspergillus oryzae Cutinase: Enhanced Thermostability and Hydrolytic Activity of Synthetic Ester and Polyester Degradation  

SciTech Connect

Cutinases are responsible for hydrolysis of the protective cutin lipid polyester matrix in plants and thus have been exploited for hydrolysis of small molecule esters and polyesters. Here we explore the reactivity, stability, and structure of Aspergillus oryzae cutinase and compare it to the well-studied enzyme from Fusarium solani. Two critical differences are highlighted in the crystallographic analysis of the A. oryzae structure: (i) an additional disulfide bond and (ii) a topologically favored catalytic triad with a continuous and deep groove. These structural features of A. oryzae cutinase are proposed to result in an improved hydrolytic activity and altered substrate specificity profile, enhanced thermostability, and remarkable reactivity toward the degradation of the synthetic polyester polycaprolactone. The results presented here provide insight into engineering new cutinase-inspired biocatalysts with tailor-made properties.

Liu, Z.; Gosser, Y; Baker, P; Ravee, Y; Li, H; Butterfoss, G; Kong, X; Gross, R; Montclare, J; et al.

2009-01-01

387

Fabric-FOSS Module  

NSDL National Science Digital Library

Fabric, a material so often taken for granted, makes a fascinating study for early-childhood students. In the Fabric Module students are introduced to a wide variety of fabrics in a systematic way, so that they become familiar with fabrics' properties, discover what happens when they are tested, and discover how they interact with other materials, including water. Archived link: http://archive.fossweb.com/modulesK-2/Fabric/index.html

FOSS Web

2011-12-14

388

Covering Walls With Fabrics.  

E-print Network

TDOC . Z TA24S.7 8873 NO.1227 WALLS with ;FABRICS Texas Agricultural Extension Service . The Texas A&M University System Daniel C. Pfannstiel, Director, College Station, Texas Covering Walls with Fabrics* When tastefully applied, fabrics... can achieve better decorative results than traditional wallpa pers and vinyls. The depth of design and inter mingling of colors and textures created with woven fabric is often impossible to duplicate. Depending on the fabric chosen and the way...

Anonymous,

1979-01-01

389

Preparation of highly exfoliated polyester-clay nanocomposites: process-property correlations.  

PubMed

A large number of polyester nanocomposite batches featuring different kinds of nanoclay surface modifiers and up to 6 wt % nanoclay were manufactured using a solvent-based technique. Montmorillonite platelets modified with ammonium ions of different chemical architectures were examined to study the effect of ammonium ions on the extent of surface reactions with long-chain fatty acids. The ammonium montmorillonite was first dispersed and suspended in acetone. This suspension was further esterificated with dotriacontanoic (lacceroic) acid to form high density brushes on the clay surface. This led to achieving higher basal plane spacing of the montmorillonite platelets due to the reduction of electrostatic interactions holding them. The outcome of the surface esterification was analyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The esterificated ammonium-modified clays were then mixed by five different mixing strategies based on the use of a three-roll mill mixer (TRM) and/or ultrasonication (US) to obtain the desired polyester-nanoclay dispersion, intercalation, and exfoliation. The dispersion states of the modified nanoclay in polymer were characterized from XRD, scanning electron microscopy (SEM), and low and high magnification transmission electron microscopy (TEM). Mechanical, thermal, and barrier properties of the resulting composites were experimentally characterized. The Mori-Tanaka method along with an orientation distribution function was used to verify the experimental effective stiffness of the polyester nanocomposite systems. The aspect ratio of nanoclays and their level of intercalation and/or exfoliation after mixing were also confirmed by the comparison of the experimental diffusivity results with those of Fick's diffusion model. Systems having 4 and 6 wt % esterificated ammonium nanoclay and prepared according to a combined TRM/US mixing procedure showed optimal performance with balanced properties and processing ease, thereby showing potential for use in the automotive, transportation, and packaging industries. PMID:22087630

Dalir, Hamid; Farahani, Rouhollah D; Nhim, Vireya; Samson, Benjamin; Lévesque, Martin; Therriault, Daniel

2012-01-10

390

Immobilized Candida antarctica lipase B: Hydration, stripping off and application in ring opening polyester synthesis.  

PubMed

This work reviews the stripping off, role of water molecules in activity, and flexibility of immobilized Candida antarctica lipase B (CALB). Employment of CALB in ring opening polyester synthesis emphasizing on a polylactide is discussed in detail. Execution of enzymes in place of inorganic catalysts is the most green alternative for sustainable and environment friendly synthesis of products on an industrial scale. Robust immobilization and consequently performance of enzyme is the essential objective of enzyme application in industry. Water bound to the surface of an enzyme (contact class of water molecules) is inevitable for enzyme performance; it controls enzyme dynamics via flexibility changes and has intensive influence on enzyme activity. The value of pH during immobilization of CALB plays a critical role in fixing the active conformation of an enzyme. Comprehensive selection of support and protocol can develop a robust immobilized enzyme thus enhancing its performance. Organic solvents with a log P value higher than four are more suitable for enzymatic catalysis as these solvents tend to strip away very little of the enzyme surface bound water molecules. Alternatively ionic liquid can work as a more promising reaction media. Covalent immobilization is an exclusively reliable technique to circumvent the leaching of enzymes and to enhance stability. Activated polystyrene nanoparticles can prove to be a practical and economical support for chemical immobilization of CALB. In order to reduce the E-factor for the synthesis of biodegradable polymers; enzymatic ring opening polyester synthesis (eROPS) of cyclic monomers is a more sensible route for polyester synthesis. Synergies obtained from ionic liquids and immobilized enzyme can be much effective eROPS. PMID:22041165

Idris, Ani; Bukhari, Attaullah

2012-01-01

391

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

PubMed

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

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

2014-03-10

392

A versatile family of degradable non-viral gene carriers based on hyperbranched poly(ester amine)s.  

PubMed

A variety of degradable hyperbranched poly(ester amine)s containing primary, secondary and tertiary amino groups, were synthesized and evaluated as non-viral gene carriers. The polymers were obtained in high yields through a Michael-type conjugate addition of diacrylate monomers with trifunctional amine monomers. Analysis of degradation products using liquid chromatography-mass spectroscopy (LC-MS) demonstrated that all poly(ester amine)s had a hyperbranched structure with a degree of branching of approximately 0.30. These poly(ester amine)s were readily water-soluble and degradable under physiological conditions (pH 7.4, 37 degrees C), in which more than 10% ester bonds were hydrolyzed within 4 h. Moreover, these hyperbranched poly(ester amine)s showed high buffering capacities between pH 5.1 and 7.4. Three out of nine synthesized polymers, i.e. p(HDDA-AEP), p(HDDA-AMP), and p(BDDA-AMP), were shown to effectively condense plasmid DNA into small-sized (approximately 94-135 nm) and positively charged complexes. Polymer/DNA complexes ('polyplexes') based on these three polymers, and larger complexes of p(BDDA-AEP) (approximately 497 nm) were able to transfect COS-7 cells in vitro. Importantly, the transfection activity of polyplexes was preserved in the presence of serum proteins. The highest transfection level was observed for p(HDDA-AEP) polyplex which had a transfection efficiency higher than or comparable to that polyplexes of polyethylenimine (PEI) and poly(2-(dimethylamino)ethyl methacrylate) (pDMAEMA). Furthermore, these poly(ester amine)s revealed no or low cytotoxicity. These results demonstrated that hyperbranched poly(ester amine)s can be applied as safe and efficient gene delivery polymers. PMID:16081184

Zhong, Zhiyuan; Song, Yan; Engbersen, Johan F J; Lok, Martin C; Hennink, Wim E; Feijen, Jan

2005-12-01

393

Application of foams to the processing of fabrics. Phase III. Technical progress report, September 1, 1979-August 31, 1980  

SciTech Connect

Objective is to reduce the energy required to evaporate the water in wet processes by using foams. By the end of August 1980 approximately 400,000,000 yards of fabric had been foam finished. Plant energy data from three UM and M plants have been collected which shows great savings. Considerable work has been done on developing applicators to apply dye and finish uniformly to flat goods. Simultaneously tinting and foam finishing by the use of a tripad show promise. Foam dyeing of nylon carpets is in production and approximately 3 million pounds of carpet have been foam dyed in one US plant. Nylon flock fabric dyeing has been scaled-up in pilot plant and plant trials. Foam dyeing of 100% polyester blankets utilizing pigment foam and disperse dye foam is in production in one textile mill. Foam pigment dyeing of flat goods by horizontal pad application shows promise by the traverse application of foam on both sides of fabric. Wet on wet foam dyeing of prepared wet fabrics is feasible. A polyester/cotton narrow width industrial toweling is now being foam dyed and finished simultaneously commercially. Foam printing using engraved rolls continues in production.

Namboodri, C.G.

1980-09-01

394

Outgassing rate of Reemay Spunbonded Polyester and DuPont Double Aluminized Mylar  

SciTech Connect

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.

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

1993-08-01

395

Biodegradable bio-based polyesters with controllable photo-crosslinkability, thermal and hydrolytic stability  

Microsoft Academic Search

Biodegradable poly{3,4-dihydroxycinnamic acid (DHCA, coffeic acid)-co-lithocholic acid (LCA)} polyester was synthesized by polycondensation of DHCA and LCA. The molecular structure of poly(DHCA-co-LCA)\\u000a copolymers was characterized by FT-IR and 1H-NMR measurement. The photo-crosslinkability of poly(DHCA-co-LCA) depended on their compositions and could be tuned by varying\\u000a the monomer ratio. The presence of LCA in the copolymers enhanced the solubility and thermal stability.

Weifu Dong; Huiling Li; Mingqing Chen; Zhongbin Ni; Jishi Zhao; Haipeng Yang; Pieter Gijsman

396

Water-extended polyester neutron shield for a 252Cf neutron source.  

PubMed

A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester was carried out. During calculations, (252)Cf and shielding were modelled and the neutron spectra as well as the H(10) were calculated in four sites. The calculation was extended to include a water shielding, the source in vacuum and in air. Besides neutron shielding characteristics, the Kerma in air due to gammas emitted by (252)Cf and due to capture gamma rays in the shielding were included. PMID:17496334

Vega-Carrillo, H R; Manzanares-Acuña, E; Hernández-Dávila, V M; Gallego, E; Lorente, A; Donaire, I

2007-01-01

397

[The kidney collecting system in man: systematization and morphometry based on 100 polyester resin casts].  

PubMed

This study was made on 100 polyester casts of human rena cavities. Four morphological types were founded on the basis of the superior, middle and inferior great calices drainage. Types AI and AII showed two great calices, types BI and BII showed an independent middle drainage. The number of small calices were not statistically correlationed to number of great calices and morphometrical renal data. The inter-pelvis-calices space was described (IPC, type AII) as well as the pelvis perpendicular small calice. PMID:3916326

Sampaio, F J; Mandarim-de-Lacerda, C A

1985-12-01

398

Metal/PET Composite Knitted Fabrics and Composites: Structural Design and Electromagnetic Shielding Effectiveness  

NASA Astrophysics Data System (ADS)

Following rapid technological advances, electronic products are being used more frequently than ever, resulting in a massive amount of interference from electromagnetic waves. In this research, stainless-steel (SS) wires, copper wires, and polyester (PET) filaments were made into SS/PET, copper/PET, and SS/copper/PET composite ply yarns. These ply yarns were then knitted into electromagnetic shielding fabrics with various knitting-needle densities. In the frequency range of 1.1 GHz to 1.4 GHz, the electromagnetic shielding effectiveness (EMSE) of the SS/PET fabric was 3.8 dB greater than that of the copper/PET composite knitted fabric, demonstrating better permeability. However, in the frequency range of 0.36 GHz to 1.1 GHz, the EMSE of the copper/PET fabric was 10 dB greater than that of the SS/PET fabric, demonstrating better conductivity. The SS/copper/PET fabrics exhibited an EMSE 10 dB greater than that of the SS/PET or copper/PET fabrics.

Huang, Chen-Hung; Lin, Jia-Horng; Yang, Ruey-Bin; Lin, Ching-Wen; Lou, Ching-Wen

2012-08-01

399

Mechanical properties of small-diameter polyurethane vascular grafts reinforced by weft-knitted tubular fabric.  

PubMed

Polyester filament yarns of different Deniers were knitted into tubular fabrics with different densities and thicknesses on a specially designed weft-knitting machine. The developed tubular fabric was used to reinforce polyurethane vascular graft and thus a kind of composite vascular graft was fabricated with a small inner diameter of 4 mm. Tensile properties of the reinforced composite vascular grafts were compared with the control tubular fabric and the pure PU vascular grafts. Elasticity and strength of the reinforced vascular grafts were improved compared with the weft-knitted tubular fabrics. Strength of the reinforced composite vascular grafts was almost 5-10 times of the strength of the pure PU vascular grafts. As the PU content increased in the reinforced composite vascular grafts, the wall thickness of the vascular graft and its strength increased, but the initial modulus of the reinforced composite vascular grafts remained similar to that of the weft-knitted tubular fabric, and the PU content showed little influence on the initial modulus of the reinforced composite vascular grafts. Microporous structure can also be fabricated in the wall of the reinforced composite vascular grafts. PMID:19165779

Xu, Weilin; Zhou, Fei; Ouyang, Chenxi; Ye, Wenxiang; Yao, Mu; Xu, Bugao

2010-01-01

400

Design and technical support for development of a molded fabric space suit joint  

NASA Technical Reports Server (NTRS)

NASA Ames Research Center has under design a new joint or element for use in a space suit. The design concept involves molding a fabric to a geometry developed at Ames. Unusual characteristics of this design include the need to produce a fabric molding draw ratio on the order of thirty percent circumferentially on the surface. Previous work done at NASA on molded fabric joints has shown that standard, NASA qualified polyester fabrics as are currently available in the textile industry for use in suits have a maximum of about fifteen percent draw ratio. NASA has done the fundamental design for a prototype joint and of a mold which would impart the correct shape to the fabric support layer of the joint. NASA also has the capability to test a finished product for suitability and reliability. Responsibilities resting with Georgia Tech in the design effort for this project are textile related, namely fiber selection, fabric design to achieve the properties of the objective design, and determining production means and sources for the fabrics. The project goals are to produce a prototype joint using the NASA design for evaluation of effectiveness by NASA, and to establish the sources and specifications which would allow reliable and repeatable production of the joint.

Olson, L. Howard

1994-01-01

401

Disinfection of fabrics and carpets artificially contaminated with calicivirus: relevance in institutional and healthcare centres.  

PubMed

Fabrics and carpets are used widely as surface coverings or linens in healthcare settings and are prone to contamination with infectious agents such as noroviruses (NoVs). Laundering, water cleaning and vacuuming are considered to be adequate for routine cleaning of these materials, but no standard procedure for their disinfection is available in case of contamination. Testing disinfectants for their efficacy against NoVs is difficult because these viruses cannot be cultivated in vitro. Therefore, feline calicivirus (FCV) has gained acceptance as a surrogate model for NoVs in disinfectant efficacy testing. The present study evaluated five disinfectants against FCV on various fabrics or carpets. FCV was dried on fabrics and carpets, followed by treatment with a given disinfectant for a defined contact time of 1, 5 or 10 min. The surviving virus was then eluted and titrated in Crandell-Reese feline kidney cells to determine virus inactivation. A disinfectant was considered to be effective if it inactivated at least 99% of the applied virus. Metricide, an activated dialdehyde-based product, was found to be the most effective disinfectant on all types of fabric and carpet, inactivating more than 99.99% of the virus in 1-10 min. In general, effectiveness of disinfectants increased with an increase in exposure time from 1 to 10 min. The disinfection of carpets was more difficult than the disinfection of fabrics; 100% polyester was the least amenable to disinfection. Only Metricide and Microbac-II (a phenolic compound) were able to inactivate 99% of FCV on 100% polyester. In summary, activated dialdehyde was found to be uniformly active against FCV on all types of material tested. PMID:16600432

Malik, Y S; Allwood, P B; Hedberg, C W; Goyal, S M

2006-06-01

402

Fabrics coated with lubricated nanostructures display robust omniphobicity  

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

403

Fabrics coated with lubricated nanostructures display robust omniphobicity.  

PubMed

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

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

2014-01-10

404

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

405

Strength properties of polyester mortar using PET and fly ash wastes  

SciTech Connect

The effect of sand and fly ash on the strength properties of polyester mortar (PM) using unsaturated polyester resins based on recycled poly(ethylene terephthalate) (PET) plastic waste have been evaluated in this study. Useful equations were also developed to predict the strength and modulus of PM using various amounts of sand and fly ash fillers individually as well as a combination of both. This evaluation is important not only from the standpoint that waste materials are being used, but also because no information is available in this area with PM using virgin materials. The test results show that the use of fly ash and PET wastes is very beneficial for the production of good-quality and relatively low-cost PM. In addition, the utilization of these wastes in PM would help save energy and alleviate an environmental problem. The PM could be utilized in a variety of construction applications such as the overlay of pavements, dams, and industrial floors, or as an adhesive to bond materials of similar or dissimilar compositions.

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

1996-04-01

406

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

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

407

Antithrombogenic polynitrosated polyester/poly(methyl methacrylate) blend for the coating of blood-contacting surfaces.  

PubMed

A nitric oxide (NO) donor polyester containing multiple S-nitrosothiol (S-NO) groups covalently attached to the polymer backbone was synthesized through the esterification of poly(ethylene glycol) with mercaptosuccinic acid, followed by the nitrosation of the -SH moieties. The polynitrosated polyester (PNPE) obtained was blended with poly(methyl methacrylate) (PMMA), yielding solid films capable of releasing NO. Scanning electron microscopy analysis showed that acrylic plates and stainless steel intracoronary stents can be coated with continuous and adherent PNPE/PMMA films. After an initial NO burst, these films release NO spontaneously in dry condition or immersed in aqueous solution at constant rates of 1.8 and 180 nmol/g/h, respectively, for more than 24 h at physiological temperature. PNPE/PMMA coated surfaces were shown to inhibit platelet adhesion when in contact with whole blood. These results show that PNPE/PMMA blend can be used for the coating of blood-contacting surfaces, with potential to inhibit thrombosis and restenosis after stenting. PMID:18370938

Seabra, Amedea B; da Silva, Regiane; de Souza, Gabriela F P; de Oliveira, Marcelo G

2008-04-01

408

Structure/property behavior of a segmented poly(ester urethane) containing different hard segment contents  

SciTech Connect

A series of poly(ester urethanes) containing different hard segment contents were synthesized to provide information on the development of hard domain structure. In contrast to previous studies, this work focuses on segmented poly(ester urethanes) containing low hard segment contents. By incrementally increasing the hard segment content, we monitored the development of the hard domain structure using thermal analysis and x-ray diffraction. Rapid quenching of the samples from the melt shows that the hard and soft segments are miscible for all compositions at elevated temperatures. If the Tg of the mixed phase is greater than ambient temperature, the structure is trapped in a metastable mixed phase. Heating the materials above the Tg causes demixing and the Tg of the soft domain decreases. If the mixed phase Tg is below ambient conditions, the hard domains spontaneously phase separate. The alternating copolymer of poly(butylene adipate) (Mn = 1K) soft segment and methylene diisocyanate (MDI) (19% hard segment) shows high poly(butylene adipate) crystallinity. The addition of very small amounts of butanediol chain extender greatly inhibits soft segment crystallization. For hard segment compositions greater than 45%, hard domains crystallize.

Orler, E. B. (E. Bruce); Wrobleski, Debra A.; Campbell, M. S. (Mary Stinecipher)

2001-01-01

409

Fire retardancy enhancement of unsaturated polyester polymer resin filled with nano and micro particulate oxide additives  

NASA Astrophysics Data System (ADS)

In the last years the traditional construction materials, such as wood, glass and steel, have been increasingly replaced by polymer composite materials due to their superior properties. However, this feature has also raised buildings' combustibility fire hazards. Polymer modification with inorganic nanoparticles can be a potential and efficient solution to control matrix flammability without sacrificing other important properties. In this study a new type of unsaturated polyester based composite materials with enhanced fire retardancy are developed, through polymer modification with nano/micro oxide particles and common flame retardants systems. For this purpose, the design of experiments based on Taguchi methodology and analyses of variance were applied. Samples with different material contents and processing parameters resultant from the L9 Taguchi orthogonal array were produced, and their fire properties assessed and quantified by single-flame source and vertical flammability tests. It was found that material and processing parameters have different effects on different properties. Unsaturated polyester composites modified with nano and micro oxide particles showed better fire performance compared to the neat composite improving at least one fire property whatever the nature of the filler. More thorough studies are required in order to improve mix design formulations towards further fire retardancy enhancement.

Ribeiro, M. C. S.; Sousa, S. P. B.; Nóvoa, P. R. O.; Pereira, C. M.; Ferreira, A. J. M.

2014-06-01

410

Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives  

NASA Astrophysics Data System (ADS)

This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO2). The nano-TiO2 was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO2 on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO2 displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO2 in improving the ageing-resistant properties of synthetic polymer composites.

Guo, Gang; Shi, Qiwu; Luo, Yanbing; Fan, Rangrang; Zhou, Liangxue; Qian, Zhiyong; Yu, Jie

2014-05-01

411

The role of the substrate in micro-scale scratching of epoxy-polyester films  

NASA Astrophysics Data System (ADS)

The present investigation analyzes the deformation response of electrostatically sprayed epoxy-polyester powder coatings by 'in situ' micro-mechanical tests. The characterization of the performance of the coatings was carried out by micro-scale scratching, by varying the indenter type, the applied load and the sliding speed. The tests were carried out on polymeric coatings deposited on as-received, micro and macro-corrugated AISI 304 stainless steel substrates and 'rigidly adhered' to them. Further tests were performed on 'free-standing' coatings, that is, on the as-received metal substrates pre-coated with an intermediate layer of silicon-based heat curable release coating. Experimental data allow us to evaluate the influence of the contact conditions between substrate and indenter and the role of the loading conditions on the scratch and penetration resistance of the epoxy-polyester coatings. The different responses of the polymeric coatings when deposited on untreated or pre-treated substrates as well as on an intermediate layer of release coating, contribute to a better understanding of the intrinsic roles of the polymeric material and substrate as well as the influence of the interfacial adhesion between coating and substrate.

Barletta, M.; Gisario, A.

2011-02-01

412

Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives  

PubMed Central

This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO2). The nano-TiO2 was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO2 on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO2 displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO2 in improving the ageing-resistant properties of synthetic polymer composites. PMID:24872802

2014-01-01

413

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

414

Fabrics with tunable oleophobicity  

E-print Network

A simple “dip-coating” process that imbues oleophobicity to various surfaces that inherently possess re-entrant texture, such as commercially available fabrics, is reported. These dip-coated fabric surfaces exhibit reversible, ...

McKinley, Gareth H.

415

FabricLink  

NSDL National Science Digital Library

Some say that the binding relationships between individuals are the fabric of human society, where others are more interested in, well, actual fabric. For those who are interested in the wide world of fabric and related topics, the FabricLink website is a fine place to learn about various fabrics, their care, fabric products, and the latest in fabric industry news and innovation. First-time visitors will want to wind their way over to the Consumer Guide section straight away. Here they will find the fabric care center, which provides helpful stain removal hints, and information about those sometimes cryptic care symbols on various items of apparel. The home furnishings area contains a number of reference guides, and a whole section dedicated to "Yarn Facts".

416

Contextualizing urban mobile fabrics  

E-print Network

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 ...

Lin, Michael Chia-Liang

2007-01-01

417

DESIGN [fabrication] BUILD  

E-print Network

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 ...

Rader, Nicolas Glen

2006-01-01

418

Fabrication of Superhydrophilic Wool Fabrics By Nanotechnology  

NASA Astrophysics Data System (ADS)

Because of the fatty layer on its surface, wool fiber is hydrophobic, which results in poor water absorption and wicking properties that affect the comfort of wool textiles. The purpose of this research is to improve the wettability and comfort of wool textiles using nanotechnology. To reveal the knowledge gaps and ensure the originality of this study, a critical review of literature was conducted in relevant areas. To achieve the objectives of the research, a simple method for fabricating environmentally stable superhydrophilic wool fabrics was developed. Silica sols with diameters of 27 nm were prepared and then coated on the surface of pristine wool fibers to form an ultrathin layer, increasing both the surface roughness and energy. The morphology and composition of silica-sol-coated wool fabrics were characterized by a combination of SEM, TEM, FTIR, and XPS measurements. After evaluating the wettability and washing durability of the silica-sol-coated wool fabrics, it was found that the durability of these wool fabrics needed to be improved. To achieve superhydrophilic wool fabrics with good washing durability, reactive siloxane was functionalized on wool fiber surface, and an ultrathin silica nanoparticles layer was grafted on the surface by in-situ growth method. To evaluate the wettability change of silica grafted wool fabric, in addition to the contact angle, in-depth characterizations of water absorbing and drying properties of wool fabrics were measured. According to Chinese National Standard (GB/T 21655.1-2008 and GB/T 21655.2-2009), the prepared silica grafted wool fabric has excellent water absorbing and quick drying properties that can be maintained after washing 20 times in a washing machine. The strategy of siloxane bonding and in-situ growth was successfully extended to durable multifunctional wool fabrics combined with superhydrophilic, self-cleaning, and antibacterial properties. To study the relationships between functional properties and nano scale morphology of the wool textile materials, silica nanoparticles of 50, 150, and 300 nm were fabricated and coated on the wool fabric surface, The wettability of wool fabric modified with the silica nanoparticles depended on both surface energy and roughness, and it was found that surface roughness was a key factor.

Chen, Dong

419

Reduction in the body content of DDE in the Mongolian gerbil treated with sucrose polyester and caloric restriction  

SciTech Connect

It has previously been shown that oral administration to rats of sucrose polyester (SPE4), a nonabsorbable lipophilic binding agent, greatly stimulates the fecal excretion of coorally administered DDT5. To determine whether this agent would stimulate the excretion of persistent metabolites of DDT stored in body tissues, we treated a group of gerbils with (/sup 14/C)-DDT and monitored the fecal excretion of radioactivity for several months until a terminal, log-linear phase of excretion was observed. At this point, when greater than 75% of the fecal radioactivity was identified as (/sup 14/C)DDE, we fed the animals diets containing up to 10% sucrose polyester and found that the rate of excretion of radioactivity in the stool promptly increased two to three times as compared to the rate in the preceding control period. Some rats were subjected to a 25-50% restriction in total food allotment, but this produced no significant change in fecal excretion of total radioactivity. However, when food restriction was combined with administration of sucrose polyester, there was a dramatic, eightfold average increase in excretion of fecal radioactivity. This synergistic effect was reversed (within 24 hr) when the animals were transferred to a normal diet. Measurement of total body radioactivity confirmed that food restriction plus sucrose polyester treatment reduced the body content of the pesticide. We conclude that stimulation of intestinal excretion may offer a new approach to treatment of patients exposed to lipophilic environmental contaminants.

Mutter, L.C.; Blanke, R.V.; Jandacek, R.J.; Guzelian, P.S.

1988-03-15

420

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

SciTech Connect

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.

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

421

Identification of the major polyunsaturated C 16 acids of marine oils by GLC separation factors on normal and organosilicone polyesters  

Microsoft Academic Search

The tentative identification of the unsaturated C16 acids of marine oils is facilitated through analysis on both normal and organosilicone polyester substrates. Two different\\u000a separation factors can then be approximated from the more accessible separation factors appropriate to unsaturated acids of\\u000a longer chain lengths.

R. G. Ackman; P. M. Jangaard

1963-01-01

422

Smoke, CO, and CO2 Measurements and Evaluation using Different Fire Testing Techniques for Flame Retardant Unsaturated Polyester Resin Formulations  

Microsoft Academic Search

Smoke is considered to be the main fire hazard but its production depends on major variables, principally the chemical character and the burning rate of the polymer plus the availability of oxygen and hence ventilation. The main aim of this work is to study the effect of smoke suppressants on flammability and smoke production of flame retarded unsaturated polyester resin-nanocomposites

S. Nazaré; B. K. Kandola; A. R. Horrocks

2008-01-01

423

The Interfacial Bond Strength in Glass Fibre-Polyester Resin Composite Systems Part 2. The Effect of Surface Treatment  

Microsoft Academic Search

The effect of surface treatments on the bond strength in glass fibre-polyester resin composites has been investigated using single fibre interfacial shear strength specimens and the short beam shear test for interlaminar shear strength.A range of bond strengths was obtained by using, either alone or in combination, the various components of the size formulation which is normally applied to the

H. W. C. Yip; J. B. Shortall

1976-01-01

424

Polyester and nylon powders used as pollen diluents preserve pollen germination and tube growth in controlled pollinations  

Microsoft Academic Search

Pollen acquisition for seed production, breeding programs and supplemental pollination can be costly and difficult. The identification of dry particulates for use as pollen diluents would facilitate the use of limited amounts of pollen and aid in accurate pollen application and dispersion. Four powders - Rilsan ES, polyester, wheat flour, and Lycopodium spores - were evaluated as pollen diluents using

Weiguang Yi; Edward S. Law; Hazel Y. Wetzstein

2003-01-01

425

THE PHASE BEHAVIOR OF FLUORINATED DIOLS, DIVINYL ADIPATE, AND A FLUORINATED POLYESTER IN SUPERCRITICAL CARBON DIOXIDE. (R828131)  

EPA Science Inventory

The use of supercritical carbon dioxide as a reaction medium for polyester synthesis is hindered by the low solubility of diols in CO2. However, it has been previously demonstrated that fluorinated compounds can exhibit greater miscibility with carbon dioxide than t...

426

Cure characterization of an unsaturated polyester resin using near-infrared, fluorescence and UV/visible reflection spectroscopies  

NASA Astrophysics Data System (ADS)

This dissertation seeks to characterize the cure reaction of an unsaturated polyester resin using near-infrared, fluorescence and UV/Visible reflection spectroscopies. The results will provide a foundation for developing fiber-optic in-situ cure monitoring techniques based on near-infrared, fluorescence, and UV/Visible reflection spectroscopies for an unsaturated polyester resin system. Near-infrared spectra of the unsaturated polyester resin during cure showed a decrease in absorption at 1629, 2087, 2117, and 2227 nm. Model compounds representing the reactants and products of the cure reaction were characterized, and assignment of peaks in the NIR were made. Conversion of styrene and vinylene, determined from NIR measurements, were compared with values obtained using conventional FTIR measurements. Discrepancies between conversion values determined from NIR and FTIR measurements were attributed to a difference in sample sizes used for measurement. Using a microgel based reaction mechanism, the effects of temperature on the conversion of styrene and vinylene was discussed. A strong fluorescence emission was found during cure of the unsaturated polyester resin. As the reaction proceeded, the emission intensity at 306 nm increased. Model compound studies confirmed that the unsaturated polyester vinylene component exhibits negligible fluorescence when excited at 250 nm. The fluorescence emission at 306 nm was attributed to a reduced self-quenching effect of styrene monomer. In-situ fluorescence characterization of the cure reaction was also attempted. Fiber-optic fluorescence measurements taken in-situ at 75°C were found to be higher than those taken by fiber-optics at room temperature, indicating a temperature effect on the fluorescence emission. These results may be a consequence of the static quenching behavior of styrene monomer. UV/Visible reflection spectra of styrene showed a decrease in the % Reflectance at 255 nm with reaction time. This decrease was attributed to an overall reduction in the absorption index as styrene reacts to form polystyrene. Conversion of styrene calculated from UV/Visible reflection and FTIR measurements were in close agreement. A preliminary investigation into the use of UV/Visible reflection spectroscopy to cure monitor a styrene containing unsaturated polyester resin was also performed. A similar decrease in the % Reflectance at 255 nm with cure time was reported for the unsaturated polyester resin.

Grunden, Bradley Lyn

427

Ab initio and DFT derived potential energy functions in simulations of selected polyesters based on atomistic models  

NASA Astrophysics Data System (ADS)

This study focuses on atomistic simulations of polyesters, the main interest being in the performance of classical models. The Polymer Consistent Force Field (PCFF), developed for synthetic polymers, forms the basis for the simulations. The calculated properties of synthetic polymers depend strongly on the conformational statistics of the polymer chains, and the force field is, therefore, of crucial importance for the reliability of the simulations. Thus, the PCFF has been tested by comparing its results for model molecules of the polyesters studied with those of quantum mechanical ab initio and density functional theory (DFT) calculations regarding the rotational behaviour of typical bonds in these polyesters. The calculations showed that there were severe disagreements between the quantum mechanical and the PCFF studies, leading thus to re-optimisation of the particular torsion potentials of the PCFF. The quantum mechanical methods used were also compared, and though they gave mostly similar results, the DFT methods were found to underestimate some of the torsional barriers. The modified PCFF was shown to yield results in good agreement with experimental data for single chain properties of the selected polyesters. The dependence of the RIS Metropolis Monte Carlo (RMMC) method, used for these property calculations, on different run parameters, was discussed in more detail. The RMMC method, using the original and modified PCFFs, was also used in studies on the flexibility of some polyesters, which are known to be biodegradable, i.e. of polylactic (PLA) and polyglycolic (PGA) acids and some of their copolymers. The original PCFF was found to reproduce the flexibilities of these polyesters in contradiction with the results obtained with the modified PCFF. Finally, the modified PCFF was applied to molecular dynamics simulations on the constructed amorphous models for PLA and PGA and some of their copolymers to study the probability for hydrolysis as the first stage of biodegradation. The main conclusion of this study is, that re- optimisation of the torsion parameters was necessary to reproduce the torsional behaviour obtained by QM methods. The modified PCFF can, thus, be reliably used in single chain property calculations and in studies on bulk material properties of polyesters containing structural units studied in this work.

Blomqvist, Johanna Marjaana

428

Publications Fabrice Rossi  

E-print Network

Publications Fabrice Rossi 2 mars 2014 Nombre de publications Revues avec comité de lecture et internationales avec comité de lecture [AI-1] Marie Cottrell, Madalina Olteanu, Fabrice Rossi, Joseph Rynkiewicz 26 (4 nov. 2012), p. 373­380. [AI-2] Fabrice Rossi et Nathalie Villa-Vialaneix. « Consistency

Rossi, Fabrice

429

Exploring Products: Nano Fabrics  

NSDL National Science Digital Library

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.

Nanoscale Informal Science Education Network

2010-01-01

430

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

PubMed

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

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

2014-11-01

431

Design, Fabrication, Digital Between digital design and digital fabrication  

E-print Network

Design, Fabrication, Digital Between digital design and digital fabrication Shaghayegh Shadkhou1 manufacturing. CFD (conception, fabrication, digitale) is a one week workshop with graduate (master recherche form generation interweaving geometry, aspects of construction and fabrication technologies. Key words

Paris-Sud XI, Université de

432

Amyloid-Like Hierarchical Helical Fibrils and Conformational Reversibility in Functional Polyesters Based on l-Amino Acids.  

PubMed

The present investigation reports one of the first examples of synthetic polymers that capable of undergoing reversible conformation transformation and also self-assembled to hierarchical helical amyloid-like fibrils. A new temperature selective melt polycondensation reaction was developed for amino acid monomers l-aspartic acid and l-glutamic acid to produce high molecular weight linear functional polyesters. These new polyesters have hydrogen bonded urethane (or carbamate) units that are in-built in each repeating unit. The polymer chains have adapted expanded chain conformation through ?-sheet hydrogen bonding interactions and produced twisted ribbon-like assemblies. These twisted ribbons have subsequently undergone interchain folding for making double helical structures. The double helical fibrils aligned together to produce amyloid-like fibrils of few micrometer in length. Upon chemical deprotection of the pendent urethane units; the resultant cationic functional polyester adapted coil-like conformation and exhibited spherical charged nanoparticles of 200 ± 20 nm in size. Dynamic light scattering and zeta potential measurements revealed that both the charge and size of the spherical structures could be varied by altering the diol segment length in the polymer backbone. The coil-like chains in the charged spherical particles could be reversibly expanded into amyloid-like fibrils via fluorophore chemical substitution using dansyl chloride. The dansyl-substituted polymer exhibited helical fibrils and strong fluorescence. Thus, the l-amino acid based polyesters exhibited complete reversible conformational changes from hierarchical helical amyloid-like fibrils to charged nanoparticles in a single polymer system. These new nonpeptide polyester analogues, their amyloid fibrils, cationic polymer assemblies and fluorescent fibrils are very new based on l-amino acids, which may be useful for a wide range of biomedical applications. PMID:25642786

Anantharaj, Santhanaraj; Jayakannan, Manickam

2015-03-01

433

Photochemical cutting of fabrics  

SciTech Connect

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.

Piltch, M.S.

1994-11-22

434

Photochemical cutting of fabrics  

DOEpatents

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.

Piltch, Martin S. (Los Alamos, NM)

1994-01-01

435

Fabrication of implantable microshunt using  

E-print Network

Fabrication of implantable microshunt using a novel channel sealing technique Alioune Diouf microelectromechanical systems MEMS fabrication processes. The key features of our mi- croshunt fabrication process fabrication process suitable for mass production. These features were realized using electroplating

436

Women's Trail lite Therma-Rest Updated for 2014: Like the unisex Trail Lite mattress, the  

E-print Network

15 Volume 2080 cu. in 2160 cu. in Top fabric type 75d Polyester Print 75d Polyester Print Bottom fabric type 75d Polyester 75d Polyester 1 Die Cut Urethane Foam Die Cut Urethane Foam Country of Origin

Walker, Lawrence R.

437

Cure characterization of thick polyester composite structures using dielectric and finite difference analysis  

SciTech Connect

Disposable and permanently mounted dielectric sensors were used to characterize the cure in polyester sheet molding compound (SMC) at various locations through the thickness of the part in a simulated molding environment. Using established techniques, the dielectric and temperature information were combined to yield local cure state information for each sensor. Parts under five millimeters thick were found to cure rather uniformly while parts greater than this had increasing degrees of nonuniformity in cure behavior through the thickness. These observed cure state data were compared to finite difference model predictions. The model predictions, which were confirmed by the sensor cure data, may be used to optimize part design and production by predicting the curing behavior and molding cycle time required for new structures.

Day, D.R. [Micromet Instruments Inc., Newton Centre, MA (United States)

1993-12-31

438

Hemp-Fiber-Reinforced Unsaturated Polyester Composites: Optimization of Processing and Improvement of Interfacial Adhesion  

SciTech Connect

The processing variables for making hemp-fiber-reinforced unsaturated polyester (UPE) composites were optimized through orthogonal experiments. It was found that the usage of initiator, methyl ethyl ketone peroxide, had the most significant effect on the tensile strength of the composites. The treatment of hemp fibers with a combination of 1, 6-diisocyanatohexane (DIH) and 2-hydroxylethyl acrylate (HEA) significantly increased tensile strength, flexural modulus of rupture and flexural modulus of elasticity, and water resistance of the resulting hemp-UPE composites. FTIR spectra revealed that DIH and HEA were covalently bonded to hemp fibers. Scanning electronic microscopy graphs of the fractured hemp-UPE composites demonstrated that treatment of hemp fibers with a combination of DIH and HEA greatly improved the interfacial adhesion between hemp fibers and UPE. The mechanism of improving the interfacial adhesion is proposed.

Qui, Renhui; Ren, Xiaofeng; Fifield, Leonard S.; Simmons, Kevin L.; Li, Kaichang

2011-02-25

439

Monitoring the hydrolytic degradation of polyester-based composites by a piezoelectric method  

SciTech Connect

Theoretical considerations show that the electric impedance of a piezoelectric element depends on the physical and geometrical properties of the element and also on the viscoelastic characteristics of the different media surrounding it. According to a dynamic model, an original technique has been developed by inserting a piezoelectric ceramic in the composite structure when processed. The electric signal, after signal processing and numerical treatments, gives access to the viscoelastic properties of the external medium. This method is an excellent indicator to display the polymerization kinetics of the resin as well as the post-curing phase of the composite structure process. Moreover, a further application of this non-destructive method is the monitoring of the hydrolitic degradation of the composite structure. The evolution of the electric impedance of the piezoelectric sensor is presented here as a function of water exposition time for a polyester-based composite.

Sainte-Pierre, N.; Perrissin, I.; Jayet, Y.; Tatiboueet, J. [Inst. National des Sciences Appliquees de Lyon, Villeurbanne (France)

1995-10-01

440

Effects of surface modification to rubber particles on the toughening of polystyrene, polyester and epoxy systems  

SciTech Connect

Preliminary work has been done for the improvement of impact properties of rubber-toughened polystyrene, rubber-toughened epoxy, and rubber-toughened polyester. Unmodified ground tire rubber particles are being compared to two types of surface-modified particles, including: Vistamer{trademark} R-4200 from Composite Particles, Inc. and a chemically digested rubber. By chemically reacting the particles with the matrix, we achieve significant improvement in impact resistance resulting from enhanced energy dispersion. Particle size and particle size distribution, studied through image analysis, is an important parameter controlling impact and fracture strength. The smaller particle size of the digested rubber composites, combined with its surface treatment, significantly improves the mechanical properties of these composites over the properties of the larger, unmodified ground rubber-toughened composites and Vistamer{trademark} surface treated composites.

Hampton, J.M.; Yao, G.L.; Joseph, T.M.; Beatty, C.L. [Univ. of Florida, Gainesville, FL (United States)

1996-12-31

441

High diffraction efficiency polarization gratings recorded by biphotonic holography in an azobenzene liquid crystalline polyester  

SciTech Connect

High diffraction efficiencies have been achieved with polarization gratings recorded in thin films of an azobenzene side-chain liquid crystalline polyester by means of biphotonic processes. Efficiency values up to 30% have been reached after an induction period of 300 s and subsequent evolution with the sample in darkness. These values are at least two orders of magnitude higher than those previously reported for biphotonic recording. The gratings can be erased with unpolarized blue light and partial recovery of the diffraction efficiency has been observed after the erasure process when the sample is kept in darkness. Red light illumination of the erased film increases the recovered efficiency value and the recovery rate. {copyright} 2001 American Institute of Physics.

Sanchez, C.; Alcala, R.; Hvilsted, S.; Ramanujam, P. S.

2001-06-18

442

The Relationship Between Microstructure and Toughness of Biaxially Oriented Semicrytalline Polyester Films  

SciTech Connect

The relationship between microstructure and toughness of biaxially stretched semicrystalline polyester films was investigated. Optically transparent films were prepared by simultaneous biaxial stretching of melt-cast sheets near the glass transition temperature. Copolyesters of polyethylene terephthalate (PET) with different compositions of two diols: ethylene glycol (EG) and cyclohexane dimethanol (CHDM), and stoichiometrically matched terephthalic acid were used to produce films with different degrees of crystallinity. In addition, the PET films with different crystalline morphologies were produced by constrained high temperature annealing of biaxially oriented films. The toughness, degree of crystallinity and crystalline morphology/molecular ordering were studied using mechanical testing, synchrotron small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD) techniques, and differential scanning calorimetry (DSC). The results indicate that the toughness of a semicrystalline polymeric film is determined by the interconnectivity of the crystalline phase within the amorphous phase and is greatly influenced by the degree of crystallinity and the underlying crystalline morphology.

Rao,Y.; Greener, J.; Avila-Orta, C.; Hsiao, B.; Blanton, T.

2008-01-01

443

In-Channel Atom-Transfer Radical Polymerization of Thermoset Polyester Microfluidic Devices for Bioanalytical Applications  

PubMed Central

A new technique for polymer microchannel surface modification, called in-channel atom-transfer radical polymerization, has been developed and applied in the surface derivatization of thermoset polyester (TPE) microdevices with poly(ethylene glycol) (PEG). X-ray photoelectron spectroscopy, electroosmotic flow (EOF), and contact angle measurements indicate that PEG has been grafted on the TPE surface. Moreover, PEG-modified microchannels have much lower and more pH-stable EOF, more hydrophilic surfaces and reduced nonspecific protein adsorption. Capillary electrophoresis separation of amino acid and peptide mixtures in these PEG-modified TPE microchips had good reproducibility. Phosducin-like protein and phosphorylated phosducin-like protein were also separated to measure the phosphorylation efficiency. Our results indicate that PEG-grafted TPE microchips have broad potential application in biomolecular analysis. PMID:17640094

Pan, Tao; Fiorini, Gina S.; Chiu, Daniel T.; Woolley, Adam T.

2012-01-01

444

Suitability of hyperbranched polyester for sensoric applications--investigation with reflectometric interference spectroscopy.  

PubMed

Hyperbranched polyesters (HBP) with different end groups (P-OH, P-COOH, P-OAc) were prepared as thin films. Their surface properties were investigated using zeta potential and contact angle measurements. The differences in surface properties between P-OH and P-COOH, on the one hand, and P-OAc, on the other hand, predicted different behavior in sensoric applications. Therefore, the vapor of the homologous series of alcohols from methanol to pentanol was exposed to the thin films. Changes in thickness were observed with reflectometric interference spectroscopy (RIfS). First investigations in a current analytical problem for the detection and discrimination of refrigerants (freons) using P-OH as sensitive layer have been shown. Polydimethylsiloxane (PDMS) and poly(ether urethane) (PUT) were used as reference sensor materials for the RIfS measurements. PMID:12373386

Belge, Georg; Beyerlein, Detlev; Betsch, Carmen; Eichhorn, Klaus-J; Gauglitz, Günter; Grundke, Karina; Voit, Brigitte

2002-10-01

445

In situ X-ray Photoemission Spectroscopy Analysis of Aromatic Polyester Surface Treated with Argon Plasma  

NASA Astrophysics Data System (ADS)

Effects of surface modification treatment by argon plasma processing of two types of aromatic polyester, poly(ethylene terephthalate) (PET) and poly(oxybenzonate-co-oxynaphthoate) (POCO), were investigated. This paper presents a description of our experiment and a discussion of the surface modification mechanism, which uses a simple and inexpensive procedure to conduct analysis without breaking vacuum after plasma processing. In situ analysis of the chemical composition of a polymer surface was attempted without exposing the sample to air after argon plasma processing. In particular, the respective actions of each active species were investigated for electrons and ions in argon plasma. Electrons and ions in argon plasma break some polymer bonds. Specifically, ester groups are broken and oxygen atoms are kicked out in PET and POCO. No oxygen functional group is formed after argon plasma processing, but such groups are formed if the sample is exposed to air.

Narushima, Kazuo; Okamoto, Nanami

2013-10-01

446

Poly(glycerol-dodecanoate), a biodegradable polyester for medical devices and tissue engineering scaffolds  

PubMed Central

In this paper we describe the mechanical and biological features of a thermosetting polyester synthesized from glycerol and dodecanedioic acid named Poly-Glycerol-Dodecanoate (PGD). This polymer shows a glass transition temperature (Tg) around 32°C, and this accounts for its mechanical properties. At room temperature (21°) PGD behaves like a stiff elastic-plastic material, while at body temperature (37°C), it shows a compliant non-linear elastic behavior. Together with biodegradability and biocompatibility PGD has distinct shape memory features. After the polymer is cured, no matter what the final configuration is, we can recover the original shape by heating PGD to temperatures of 32°C and higher. The mechanical properties together with biocompatibility/biodegradability and shape memory features make PGD an attractive polymer for biomedical applications. PMID:19712970

Migneco, Francesco; Huang, Yen-Chih; Birla, Ravi K.; Hollister, Scott J.

2015-01-01

447

On the suitability of fiberglass reinforced polyester as building material for mesocosms.  

PubMed

Gel- and topcoat surface layers on fiberglass [glass-reinforced plastic (GRP)] made of unsaturated resin based on isophthalic acid polyester and neopentyl glycol (ISO-NPG) were tested for leaching, ecotoxicity of water eluates, and abrasion by river sediments at a current speed of 0.5 m * s-1. Leaching from topcoat tempered at low temperature was significant, whereas it was negligible from highly tempered gelcoat. Water eluates from both gel-and topcoat were nontoxic in routinely employed biotests (bacteria, algae, daphnids). No abrasion by river sediments was detectable. Based on these results, GRP with gelcoat made of ISO-NPG is considered a suitable building material for mesocosms. PMID:10381304

Berghahn, R; Brandsch, J; Piringer, O; Pluta, H J; Winkler, T

1999-07-01

448

N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters  

PubMed Central

Summary Isosorbide was esterified with acryloyl chloride and crotonic acid yielding isosorbide diacrylate (9a) and isosorbide dicrotonate (9b), which were reacted with benzaldehyde oxime in the presence of zinc(II) iodide and boron triflouride etherate as catalysts to obtain N-alkylated dinitrones 10a/b. Poly(isosorbide itaconite -co- succinate) 13 as a bio-based unsaturated polyester was cross-linked by a 1,3-dipolar cycloaddition with the received dinitrones 10a/b. The 1,3-dipolar cycloaddition led to a strong change of the mechanical properties which were investigated by rheological measurements. Nitrones derived from methyl acrylate (3a) and methyl crotonate (3b) were used as model systems and reacted with dimethyl itaconate to further characterize the 1,3-dipolaric cycloaddition. PMID:24991239

Goerz, Oliver

2014-01-01

449

Test plan for immobilization of salt-containing surrogate mixed wastes using polyester resins  

SciTech Connect

Past operations at many Department of Energy (DOE) sites have resulted in the generation of several waste streams with high salt content. These wastes contain listed and characteristic hazardous constituents and are radioactive. The salts contained in the wastes are primarily chloride, sulfate, nitrate, metal oxides, and hydroxides. DOE has placed these types of wastes under the purview of the Mixed Waste Focus Area (MWFA). The MWFA has been tasked with developing and facilitating the implementation of technologies to treat these wastes in support of customer needs and requirements. The MWFA has developed a Technology Development Requirements Document (TDRD), which specifies performance requirements for technology owners and developers to use as a framework in developing effective waste treatment solutions. This project will demonstrate the use of polyester resins in encapsulating and solidifying DOE`s mixed wastes containing salts, as an alternative to conventional and other emerging immobilization technologies.

Biyani, R.K.; Douglas, J.C.; Hendrickson, D.W.

1997-07-07

450

Isosorbide as the structural component of bio-based unsaturated polyesters for use as thermosetting resins.  

PubMed

In recent years, the development of renewable bio-based resins has gained interest as potential replacements for petroleum based resins. Modified carbohydrate-based derivatives have favorable structural features such as fused bicyclic rings that offer promising candidates for the development of novel renewable polymers with improved thermomechanical properties when compared to early bio-based resins. Isosorbide is one such compound and has been utilized as the stiffness component for the synthesis of novel unsaturated polyesters (UPE) resins. Resin blends of BioUPE systems with styrene were shown to possess viscosities (120-2200 cP) amenable to a variety of liquid molding techniques, and after cure had Tgs (53-107 °C) and storage moduli (430-1650 MPa) that are in the desired range for composite materials. These investigations show that BioUPEs containing isosorbide can be tailored during synthesis of the prepolymer to meet the needs of different property profiles. PMID:24188843

Sadler, Joshua M; Toulan, Faye R; Nguyen, Anh-Phuong T; Kayea, Ronald V; Ziaee, Saeed; Palmese, Giuseppe R; La Scala, John J

2014-01-16

451

Adhesion analysis of non-woven natural fibres in unsaturated polyester resin  

NASA Astrophysics Data System (ADS)

The presence of wool fibres in non-woven Alfa fibres sheet was investigated as a mean of improving adhesion of Alfa fibre-reinforced unsaturated polyester composite. FT-IR and Raman spectroscopy results revealed that such improvement could occur by a decrease in the hydrophilic character of the Alfa fibres owing to the presence of wool fibres. Hence, physical and chemical interactions could happen between the reinforcement and the matrix as demonstrated by FT-IR and Raman spectroscopy results. Tensile testing performed on this composite confirmed that such adhesion could occur according to its excellent specific parameters despite of its low tensile strength attributed to a higher fibre to fibre contact of wool fibres.

Omri, Med Amin; Triki, A.; Guicha, M.; Ben Hassen, Med; Arous, M.; Ahmed El Hamzaoui, H.; Bulou, A.

2015-03-01

452

Usefulness of an aluminized polyester film for reducing heat in polyethylene calf hutches  

NASA Astrophysics Data System (ADS)

This study determined the efficacy of a radiant barrier material used in the construction industry to moderate summer temperatures in polyethylene calf hutches. The cover consisted of a single layer of two-sided reflective aluminized polyester film with a center polyester scrim reinforcement (reflectivity = 95 %). At each of two dairies, six hutches containing a young calf were either uncovered (control) or had reflective covers across the top and sides of the hutch, leaving the front, back, and 1.2 × 1.8-m attached outdoor wire pen exposed. Duplicate loggers mounted 20 cm above the flooring in the center of each hutch recorded interior temperature at 30-min intervals over 22 days during late August to early September. The mean daily interior peak temperatures in each of the hutches over 21 days of observation were significantly less (P < 0.001) in the hutches with reflective covers (37.48 ± 0.14 °C) than in the uncovered hutches (41.65 ± 0.45 °C) and did not differ (P = 0.77) between dairies. The mean daily interior peak temperatures in each of the hutches over the warmest 10 days of observation were significantly less (P < 0.001) in hutches with reflective covers (40.15 °C ± 0.16) than in the uncovered hutches (44.93 ± 0.47 °C). The mean interior ceiling temperatures in each of the hutches over 4 days of observation were significantly lower (P < 0.001) in the hutches with reflective covers (37.82 ± 0.36 °C) than in the uncovered hutches (46.89 ± 0.47 °C). The reflective cover used in this study moderated interior hutch temperatures but showed signs of delamination after 22 days and was relatively expensive, so more suitable material needs to be identified.

Binion, W. R.; Friend, T. H.; Holub, G. A.

2014-01-01

453

Formation and Morphology of "shish-like" Fibril Crystals of Aliphatic Polyesters from the Sheared Melt  

SciTech Connect

We found the formation of 'shish-like' fibril crystals of aliphatic polyesters such as poly(L-lactic acid) (PLLA), poly({var_epsilon}-caprolactone) (PCL), poly(12-hydroxydodecanoic acid) (PHDA) and poly(16-hydroxyhexadecanoic acid) (PHHA) from the sheared melt with shear rate {gamma} = 5 s{sup -1} observed by polarizing optical microscope (POM). The melting temperature T{sub m}s of obtained fibril crystals of PLLA and PCL were higher than those of spherulites and were close to the equilibrium melting temperature T{sub m}{sup 0}. The small angle X-ray scattering (SAXS) patterns from the bulk sample including fibril crystals, small amount of unoriented small crystals and amorphous showed no peaks arose from the existence of long periods in fibril crystals. These are the evidence that the observed fibril crystals consist of assemblies of a lot of extended chain crystals (ECCs). We observed the morphology of moderately extracted single strand of fibril crystals at the magnification of POM by means of scanning electron microscope. We found that macroscopic fibril crystals of PLLA with diameter d = 10 {micro}m consist of the bundle structure of microscopic fibril crystals with d = 2 {micro}m. From POM observation of the formation of fibril crystals of PLLA and PCL, we showed phase diagrams of molecular weight M and crystallization temperature T{sub c} for the formation of fibril crystals. From these phase diagrams, we evaluated a critical M and T{sub c} for the formation of fibril crystals. Moreover, from the sequential melting and crystallization experiments, it was implied that the entanglement and transesterification play an important role on the formation of fibril crystals of aliphatic polyesters.

Yamazaki, S.; Itoh, M; Oka, T; Kimura, K

2010-01-01

454

Usefulness of an aluminized polyester film for reducing heat in polyethylene calf hutches.  

PubMed

This study determined the efficacy of a radiant barrier material used in the construction industry to moderate summer temperatures in polyethylene calf hutches. The cover consisted of a single layer of two-sided reflective aluminized polyester film with a center polyester scrim reinforcement (reflectivity?=?95%). At each of two dairies, six hutches containing a young calf were either uncovered (control) or had reflective covers across the top and sides of the hutch, leaving the front, back, and 1.2?×?1.8-m attached outdoor wire pen exposed. Duplicate loggers mounted 20 cm above the flooring in the center of each hutch recorded interior temperature at 30-min intervals over 22 days during late August to early September. The mean daily interior peak temperatures in each of the hutches over 21 days of observation were significantly less (P?

Binion, W R; Friend, T H; Holub, G A

2014-11-01

455

Enzymatic degradation of polyester films by a cutinase-like enzyme from Pseudozyma antarctica: surface plasmon resonance and atomic force microscopy study.  

PubMed

Enzymatic degradation of polyester films by a cutinase-like enzyme from Pseudozyma antarctica JCM10317 (PaE) was analyzed by surface plasmon resonance (SPR). The adsorption of PaE and the degradation rate for polyester films were quantitatively monitored by a positive and negative SPR signal shifts, respectively. The decrease in SPR signal and the erosion depth of amorphous poly(L-lactide) (a-PLLA) film measured by atomic force microscopy (AFM) had a linear relationship, and the weight loss was estimated from the AFM data combined with a density of a-PLLA film. Furthermore, SPR sensorgrams for various polyester films showed that degradation rate of poly(?-caprolactone) and poly(butylene succinate-co-adipate) which contain C6 units was higher than that of other polyesters such as poly(butylene succinate) and a-PLLA. These results suggest that C6 is the preferred chain length as substrates for PaE. PMID:23339012

Shinozaki, Yukiko; Kikkawa, Yoshihiro; Sato, Shun; Fukuoka, Tokuma; Watanabe, Takashi; Yoshida, Shigenobu; Nakajima-Kambe, Toshiaki; Kitamoto, Hiroko K

2013-10-01

456

Polymer radiation curing: polyester resins. January 1973-December 1988 (Citations from the Rubber and Plastics Research Association data base). Report for January 1973-December 1988  

SciTech Connect

This bibliography contains citations concerning the formulations and processes for radiation curing on polyester resins. Effects of radiation curing on polyester resins are also discussed. Electron-beam and ultraviolet radiation are emphasized. Polymer crosslinking by such electromagnetic wave radiation as in the visible wavelength is also examined. Applications in adhesives, coatings, lacquers, and printing inks are included. (Contains 200 citations fully indexed and including a title list.)

Not Available

1989-01-01

457

Reduction of polyester resin shrinkage by means of epoxy resin—II. Epoxy resin modified with acrylamide and N-hydroxymethyloloacrylamide  

NASA Astrophysics Data System (ADS)

The possibility was investigated of reducing the shrinkage of unsaturated polyester resin taking place in radiation-induced curing, by the addition of epoxy resin. In order to combine chemically both resins, the epoxy component was modified by introducing unsaturated bonds via acrylamide and N-hydroxymethyloloacrylamide. A composition of 90% unsaturated polyester resin and 10% acrylamide-modified epoxy resin, filled with silica (1:1.5), showed a volume shrinkage below 2%.

Pietrzak, M.; Brzostowski, A.

458

Fabric analysis by ambient mass spectrometry for explosives and drugs.  

PubMed

Desorption electrospray ionization (DESI) is applied to the rapid, in-situ, direct qualitative and quantitative analysis of mixtures of explosives and drugs from a variety of fabrics, including cotton, silk, denim, polyester, rayon, spandex, leather and their blends. The compounds analyzed were explosives: trinitrohexahydro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN) and the drugs of abuse: heroin, cocaine, and methamphetamine. Limits of detection are in the picogram range. DESI analyses were performed without sample preparation and carried out in the presence of common interfering chemical matrices, such as insect repellant, urine, and topical lotions. Spatial and depth profiling was investigated to examine the depth of penetration and lateral resolution. DESI was also used to examine cotton transfer swabs used for travel security sample collection in the screening process. High throughput quantitative analysis of fabric surfaces for targeted analytes is also reported. PMID:18936830

Talaty, Nari; Mulligan, Christopher C; Justes, Dina R; Jackson, Ayanna U; Noll, Robert J; Cooks, R Graham

2008-11-01

459

Testing airplane fabrics  

NASA Technical Reports Server (NTRS)

The following considerations determine the strength of airplane fabrics: 1. maximum air forces acting on the surfaces (including local stresses); 2. tensions produced in the fabrics, in the directions of both warp and filling; 3. factor of safety required. The question of the permissible depression of the fabric as affecting the aerodynamic requirements in regard to the maintenance of shape of the section, the tenacity and extensibility of the layer of dope, its strength and its permeability to water is almost as important.

Proll, A

1924-01-01

460

Universal Desktop Fabrication  

Microsoft Academic Search

Advances in digital design and fabrication technologies are leading toward single fabrication systems capable of producing\\u000a almost any complete functional object. We are proposing a new paradigm for manufacturing, which we call Universal Desktop\\u000a Fabrication (UDF), and a framework for its development. UDF will be a coherent system of volumetric digital design software\\u000a able to handle infinite complexity at any

Turlif Vilbrandt; Evan Malone; Hod Lipson; Alexander A. Pasko

2008-01-01

461

Fabrics for aeronautic construction  

NASA Technical Reports Server (NTRS)

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.

Walen, E D

1918-01-01

462

Surface Assisted Laser Desorption Ionization-Mass Spectrometry (SALDI-MS) for Analysis of Polyester Degradation Products  

NASA Astrophysics Data System (ADS)

Novel surface assisted laser desorption ionization-mass spectrometry (SALDI-MS) method was developed for rapid analysis of low molecular mass polyesters and their degradation products by laser desorption ionization-mass spectrometry. Three polycaprolactone materials were analyzed by the developed method before and after hydrolytic degradation. The signal-to-noise values obtained by SALDI-MS were 20-100 times higher compared with the ones obtained by using traditional MALDI-MS matrices. A clean background at low mass range and higher resolution was obtained by SALDI-MS. Different nanoparticle, cationizing agent, and solvent combinations were evaluated. Halloysite nanoclay and magnesium hydroxide showed the best potential as SALDI surfaces. The SALDI-MS spectrum of the polyester hydrolysis products was verified by ESI-MS. The developed SALDI-MS method possesses several advantages over existing methods for similar analyses.

Aminlashgari, Nina; Hakkarainen, Minna

2012-06-01

463

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)  

Microsoft Academic Search

Effect of different concentrations, 40–200ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200ppm). Inhibition efficiencies in the range 86–96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using

A. M. Alsabagh; M. A. Migahed; Hayam S. Awad

2006-01-01

464

Attempts to map the structure and degradation characteristics of aliphatic polyesters derived from lactic and glycolic acids  

Microsoft Academic Search

During the past 5 years, important advances have been accomplished in the understanding of the fate of aliphatic polyesters derived from lactic acid (LA) and glycolic acid (GA) in aqueous media. Hydrolysis of solid LA\\/GA polymers is now regarded as dependent upon a diffusion-reaction mechanism. Faster central degradation, degradation-induced composition, and morphology changes are three of the most important findings

M. Vert; S. M. Li; H. Garreau

1995-01-01

465

Photopolymerization behavior and properties of highly branched polyester acrylate containing thioether linkage used for UV curing coatings  

Microsoft Academic Search

The highly branched polyester acrylate containing thioether linkage (HBAT) was synthesized using an “oligomeric A2+B3” approach. The dithiol, 1,6-hexamethylene bis(3-mercaptopropionate) (HMBM), was prepared through the esterification between 1,6-hexanediol and 3-mercaptopropionic acid, and then underwent an amine-catalyzed thiol-Michael addition to the acrylic double bond of 1,6-hexamethylene diacrylate to obtain an oligomeric dithiol (oligomeric A2), then further with trimethylolpropane triacrylate as a

Yong Zhang; Hui Miao; Wenfang Shi

2011-01-01

466

Study of the thermal decomposition of flame-retarded unsaturated polyester resins by thermogravimetric analysis and Py-GC\\/MS  

Microsoft Academic Search

The thermal degradation behaviours of flame-retarded unsaturated polyester resin formulations containing ammonium polyphosphate (APP), Cloisite 25A nanoclay and zinc based smoke suppressants have been studied using thermogravimetric analysis (TGA) combined with infrared analysis of the evolved gases (EGA) and pyrolysis\\/gas chromatography–mass spectrometry (GC\\/MS). In TGA–EGA experiments, the mass loss as a function of temperature has been correlated with the evolution

Everson Kandare; Baljinder K. Kandola; Dennis Price; Shonali Nazaré; Richard A. Horrocks

2008-01-01

467

Effect of 60 Co gamma-irradiation on interface and abrasive wear of glass-reinforced polyester composite  

Microsoft Academic Search

The fibre-matrix interface in polymer composites is characterized by van der Waals'-like forces, which act between covalently bonded organic polymer and high-strength inorganic glass fibres (physisorption) and chemical bonding between the fibre and polymer, involving reactive groups (chemisorption). These mechanisms at the interface are responsible for the lowering of frictional forces and minimizing wear rate. Crosslinking polymer-like unsaturated polyesters provide

N. Chand; M. Fahim; S. G. Hussain

1993-01-01

468

Preparation and characterization of protein loaded microspheres based on a hydroxylated aliphatic polyester, poly(lactic-co-hydroxymethyl glycolic acid)  

Microsoft Academic Search

The purpose of this study was to investigate the suitability of a novel hydroxylated aliphatic polyester, poly(lactic-co-hydroxymethyl glycolic acid) (PLHMGA), as controlled release system for pharmaceutical proteins. Dextran Blue (as a macromolecular model compound) and lysozyme-loaded PLHMGA and PLGA (control formulation) microspheres were prepared by a solvent evaporation technique. The Dextran Blue and lysozyme loaded PLHMGA microspheres prepared with 10%

A. H. Ghassemi; M. J. van Steenbergen; H. Talsma; C. F. van Nostrum; W. Jiskoot; D. J. A. Crommelin; W. E. Hennink

2009-01-01

469

Reduction of polyester resin shrinkage by means of epoxy resin—I. Epoxy resin modified with acids  

NASA Astrophysics Data System (ADS)

An attempt was made to decrease the shrinkage of unsaturated polyester resin, taking place during radiation-induced curing, by the addition of epoxy resin. In order to combine chemically both resins, the epoxy component was modified with cinnamic and acrylic acids. A composition of 90 parts of polyesster resin, 10 parts of epoxy resin modified with cinnamic acid, and 150 parts of a silica filler showed a volume shrinkage of 1.2%.

Pietrzak, M.; Brzostowski, A.

470

Material and knot properties of braided polyester (Ticron ® ) and bioabsorbable poly-L\\/D-lactide (PLDLA) 96\\/4 sutures  

Microsoft Academic Search

The purpose of the present study was to investigate in vitro the biomechanical material and knot properties and histomorphometrical knot properties of 3–0 braided polyester suture (Ticron) and bioabsorbable poly-L\\/D-lactide (PLDLA) 96\\/4 suture. In Ticron five throws are needed to form a secure knot, and the\\u000a 1 = 1 = 1 = 1 = 1 and the 2 = 1

A. Viinikainen; H. Göransson; K. Huovinen; M. Kellomäki; P. Törmälä; P. Rokkanen

2006-01-01

471

Ultrasound Enhanced Plasma Treatment of Glass-Fibre-Reinforced Polyester in Atmospheric Pressure Air for Adhesion Improvement  

Microsoft Academic Search

A glass-fibre-reinforced polyester (GFRP) plate was treated with dielectric barrier discharge (DBD) at atmospheric pressure in air for adhesion improvement. The effects of ultrasonic irradiation using a high-power gas-jet generator during the treatment were investigated. The optical emission spectrum of the discharge remained almost unchanged by the ultrasonic irradiation, indicating that the bulk property of the discharge was not significantly

Yukihiro Kusano; Shailendra Vikram Singh; Kion Norrman; Frank Leipold; Joanna Drews; Per Morgen; Alexander Bardenshtein; Niels Krebs

2011-01-01

472

Miscibility, melting and crystallization behavior of two bacterial polyester\\/poly(epichlorohydrin- co-ethylene oxide) blend systems  

Microsoft Academic Search

The miscibility, melting and crystallization behavior of two bacterial polyester\\/poly(epichlorohydrin-co-ethylene oxide) (PECH–EO) blend systems was studied. PECH–EO containing 48mol% of epichlorohydrin is miscible with poly(3-hydroxybutyrate) (PHB) and with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) containing 14mol% hydroxyvalerate. Both blend systems are characterized by the existence of a single glass transition temperature (Tg) and a depression of the equilibrium melting temperature of PHB or PHBV

L. L. Zhang; S. H. Goh; S. Y. Lee; G. R. Hee

2000-01-01

473

Microspectroscopic evaluations of the interfacial degradation by absorbed water in a model composite of an aramid fibre and unsaturated polyester  

Microsoft Academic Search

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

M. Kawagoe; M. Takeshima; M. Nomiya; J. Qiu; M. Morita; W. Mizuno; H. Kitano

1999-01-01

474

Enzymatic and whole-cell synthesis of lactate-containing polyesters: toward the complete biological production of polylactate  

Microsoft Academic Search

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

Ken’ichiro Matsumoto; Seiichi Taguchi

2010-01-01

475

Dyeing of polyester with CI disperse yellow 42 in the presence of various UV-absorbers. Part II  

Microsoft Academic Search

The effect of various amounts (0·5–1·2 owf) of two benzotriazole (Tinuvin P and Tinuvin 320) and one benzophenone (Ultrafast 800) type UV-absorbers applied directly in the dyeing of polyester fibres with CI Disperse Yellow 42 at various depths (0·5, 1·0 and 2·0% owf), or by after-treatment of the dyed fibre, was studied. Combinations of Tinuvin 320 with various amounts of

E. G. Tsatsaroni; A. H. Kehayoglou

1995-01-01

476

Smart Fabrics Technology Development  

NASA Technical Reports Server (NTRS)

Advances in Smart Fabrics technology are enabling an exciting array of new applications for NASA exploration missions, the biomedical community, and consumer electronics. This report summarizes the findings of a brief investigation into the state of the art and potential applications of smart fabrics to address challenges in human spaceflight.

Simon, Cory; Potter, Elliott; Potter, Elliott; McCabe, Mary; Baggerman, Clint

2010-01-01

477

Structural Fabrication II Syllabus  

NSDL National Science Digital Library

This pdf contains a syllabus for a second course on structural fabrication as part of the Aerospace Technology Program. Topics include introduction to composites, structural fibers and matrices, core materials, basic moldless tools and techniques, and advanced composite fabrication and structural repair.

478

In vitro characterization of polyesters of aconitic acid, glycerol, and cinnamic acid for bone tissue engineering.  

PubMed

In this study, a novel class of polyesters of glycerol, aconitic acid, and cinnamic acid were synthesized along with their hydroxyapatite (HA) composites, and studied for their potential application in bone defect repair. An osteogenic study was conducted with human adipose derived mesenchymal stem cells (hASCs) to determine the osteoinductive ability of aconitic acid-glycerol (AG) polyesters, AG:HA (80:20), aconitic acid-glycerol-cinnamic acid (AGC) polyesters, and AGC:HA (80:20) to serve as bone scaffolds. The results indicate that AGC scaffolds have the highest mechanical strength in comparison to AG, AG:HA (80:20), and AGC:HA (80:20) scaffolds due to its low porosity. It was determined by cytotoxicity and osteogenesis experiments that hASCs cultured for 21 days on AG:HA (80:20) scaffolds in stromal medium exhibited a greater number of live cells than control PCL:HA composites. Moreover, hASCs cultured on foamed AG:HA (80:20) scaffolds resulted in the highest levels of mineralization, increased alkaline phosphatase (ALP) expression, and the greatest osteocalcin (OCN) expression after 21 days. Overall, AG:HA (100:0 and 80:20) scaffolds had higher mechanical strength and cytocompatibility than the PCL:HA control. In vitro osteogenic study demonstrated that AG:HA (100:0 and 80:20) synthesized using sugarcane industry by-products hold potential as scaffolds for bone tissue engineering applications. PMID:25281649

Kanitkar, Akanksha; Chen, Cong; Smoak, Mollie; Hogan, Katie; Scherr, Thomas; Aita, Giovanna; Hayes, Daniel

2015-03-01

479

New poly(ester urea) derived from L-leucine: electrospun scaffolds loaded with antibacterial drugs and enzymes.  

PubMed

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

Díaz, Angélica; del Valle, Luis J; Tugushi, David; Katsarava, Ramaz; Puiggalí, Jordi

2015-01-01

480

Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems  

PubMed Central

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

Goeschen, Catrin

2013-01-01

481

Mechanical and thermal studies of unsaturated polyester-toughened epoxy composites filled with amine-functionalized nanosilica  

NASA Astrophysics Data System (ADS)

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.

Jaya Vinse Ruban, Y.; Ginil Mon, S.; Vetha Roy, D.

2013-02-01

482

Acetone-soluble cellulose acetate extracted from waste blended fabrics via ionic liquid catalyzed acetylation.  

PubMed

Isolation of cellulose from waste polyester/cotton blended fabrics (WBFs) is a bottleneck for recycling and exploiting waste textiles. The objective of this study was to provide a new environmental-friendly and efficient approach for extracting cellulose derivatives and polyester from WBFs. A Bronsted acidic ionic liquid (IL) N-methyl-imidazolium bisulfate, [Hmim]HSO4, was used as a novel catalyst for acetylation of cellulose rather than a solvent with the aim to overcome low isolation efficiency associated with the very high viscosity and relatively high costs of ILs. The extraction yield of acetone-soluble cellulose acetate (CA) was 49.3%, which corresponded to a conversion of 84.5% of the cellulose in the original WBFs; meanwhile, 96.2% of the original poly(ethylene terephthalate) (PET) was recovered. The extracted CA was characterized by (1)H NMR, FTIR, XRD and TGA analysis, and the results indicated that high purity acetone-soluble CA and carbohydrate-free PET could be isolated in this manner from WBFs. PMID:23987361

Sun, Xunwen; Lu, Canhui; Zhang, Wei; Tian, Dong; Zhang, Xinxing

2013-10-15

483

An Investigation of Thermal Characteristic of Mechanical Crimp Textured Polyester Yarn by Differential Scanning Calorimeter (DSC)  

NASA Astrophysics Data System (ADS)

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.

Bhattacharya, Someshwar S.; Shaikh, Tasnim N.; Pratap, Arun

2010-06-01

484

Lobesia botrana IPM: electrospun polyester microfibers serve as biodegradable sex pheromone dispensers.  

PubMed

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

Hummel, Hans E; Langner, S S

2013-01-01

485

INFLUENCE OF THE DRY WOVEN FABRICS MESO-STRUCTURE ON FABRIC/FABRIC CONTACT BEHAVIOUR  

E-print Network

1 INFLUENCE OF THE DRY WOVEN FABRICS MESO-STRUCTURE ON FABRIC/FABRIC CONTACT BEHAVIOUR S. Allaoui particular periods can be exhibited. This work shows for four different architecture woven fabrics that the two periods are directly related to the meso architecture of the studied woven fabrics and more

Paris-Sud XI, Université de

486

New polymorphous computing fabric.  

SciTech Connect

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.

Wolinski, C. (Christophe); Gokhale, M. (Maya); McCabe, K. P. (Kevin P.)

2002-01-01

487

Preparation of thermosensitive membranes by radiation grafting of acrylic acid/ N-isopropyl acrylamide binary mixture on PET fabric  

NASA Astrophysics Data System (ADS)

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.

Gupta, Bhuvanesh; Mishra, Swaiti; Saxena, Shalini

2008-05-01

488

Grafting printing of cellulose fabric with the reactive disperse dyes containing N-substituted 3-chloro-2-hydroxypropyl group.  

PubMed

The printed cellulose and its blend materials have wide applications in many high-tech fields. Six new reactive disperse dyes (D1-D6) containing a 3-chloro-2-hydroxypropyl group based on epichlorohydrin were designed and synthesized. The electronic absorption spectra and their grafting printing property for cotton fabrics were investigated. The grafting mechanism on cotton fabric was also discussed. The results show that these dyes had larger bathochromic shifts in stronger polar solvent, dimethylformamide, than in the weaker polar solvents, acetonitrile and acetone. 3-Chloro-2-hydroxypropyl functional group of the dyes could form covalent bond with the hydroxyl group on cellulose by a nucleophilic substituted reaction. The good color yields of D1-D6 on printed cotton fabric were obtained by curing at 170-180 °C. The reactive disperse dyes for printing cellulose fabric had good building up and better printing property. The light fastness, rubbing fastness and fastness to perspiration of the printed fabric were good. The reactive disperse dyes have potential application in cleaner production of printing cotton and cotton/polyester blend fabrics. PMID:25256461

Li, Min; Zhang, Kai; Xie, Kongliang

2014-11-26

489

Morphological Chirality and Crystal Twinning in Different Length Scales of a Chiral Liquid Crystalline Polyester  

NASA Astrophysics Data System (ADS)

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.

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

490

Chirality Effects on the Morphology and Structure of Synthetic Chiral Main-chain Liquid Crystal Polyesters  

NASA Astrophysics Data System (ADS)

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.

Weng, X.; Li, C. Y.; Zhang, J. Z.; Bai, F.; Jin, S.; Harris, F. W.; Cheng, S. Z. D.

2002-03-01

491

Shrinkage behavior of low profile unsaturated polyester resins at low temperature and low pressure  

SciTech Connect

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.

Wen Li; Lee, L.J. [Ohio State Univ., Columbus, OH (United States)

1996-12-31

492

Effect of wool and thermo-binder fibers on adhesion of alfa fibers in polyester composite  

NASA Astrophysics Data System (ADS)

Dielectric study was investigated in order to probe the interfacial region fibers/matrix of the polyester composite reinforced with alfa/wool/thermo-binder fibers. Dielectric spectra were measured in the frequency range from 10-1 Hz to 106 Hz, and temperature interval from 40 °C to 150 °C. This study revealed the presence of two dielectric relaxations in the composite. While the first one was attributed to the ? mode relaxation associated with the glass transition of the matrix, the second was associated with the conductivity resulting from the carriers' charges diffusion noted for high temperature above glass transition and low frequencies. As this study did not show the presence of the interfacial polarization effect in the composite, it was accomplished with the vibrational study using the FT-IR and Raman techniques. A great compatibility between fibers and matrix was proven by a less hydrophilic character of the reinforcement giving rise to additional valence vibrations from wool fibers and hydrogen bonds.

Omri, Med. Amin; Triki, A.; Guicha, M.; Hassen, Med. Ben; Arous, M.; Ahmed El Hamzaoui, H.; Bulou, A.

2013-12-01

493

Study of the water barrier properties of polyester paints after photo-oxidative degradation  

SciTech Connect

The capacitance of an organic coating, applied on a metal substrate for protection against corrosion, can undergo a decrease following some deterioration processes due to the interaction with the environment. In particular, the barrier properties of a paint are strongly influenced, for example, by the presence of defects, by photo-oxidative phenomena and by the adhesive properties of the polymer-metal interface. Impedance spectroscopy is a flexible and efficacious instrument for assessing all these phenomena and is useful in supplying information on the mechanisms of deterioration as well as in assessing the physical parameters associated with it. The scope of this work is to study in detail the photosensitive effects of UV radiation on the water barrier properties of industrially produced polyester organic coating. The coefficients of diffusion and the values of permeability and saturation for different UV radiation intervals, have been calculated, starting from the impedance data and using appropriate models. So the relationship between these values and the effective long term properties of protection from corrosion of the paints was evaluated.

Deflorian, F.; Fedrizzi, L.; Bonora, P.L. [Univ. of Trento (Italy)

1996-10-01

494

Magnesium Coated Bioresorbable Phosphate Glass Fibres: Investigation of the Interface between Fibre and Polyester Matrices  

PubMed Central

Bioresorbable phosphate glass fibre reinforced polyester composites have been investigated as replacement for some traditional metallic orthopaedic implants, such as bone fracture fixation plates. However, composites tested revealed loss of the interfacial integrity after immersion within aqueous media which resulted in rapid loss of mechanical properties. Physical modification of fibres to change fibre surface morphology has been shown to be an effective method to improve fibre and matrix adhesion in composites. In this study, biodegradable magnesium which would gradually degrade to Mg2+ in the human body was deposited via magnetron sputtering onto bioresorbable phosphate glass fibres to obtain roughened fibre surfaces. Fibre surface morphology after coating was observed using scanning electron microscope (SEM). The roughness profile and crystalline texture of the coatings were determined via atomic force microscope (AFM) and X-ray diffraction (XRD) analysis, respectively. The roughness of the coatings was seen to increase from 40 ± 1?nm to 80 ± 1?nm. The mechanical properties (tensile strength and modulus) of fibre with coatings decreased with increased magnesium coating thickness. PMID:24066297

Liu, Xiaoling; Grant, David M.; Parsons, Andrew J.; Harper, Lee T.; Rudd, Chris D.; Ahmed, Ifty

2013-01-01

495

Enzyme-Catalyzed Synthesis of Unsaturated Aliphatic Polyesters Based on Green Monomers from Renewable Resources  

PubMed Central

Bio-based commercially available succinate, itaconate and 1,4-butanediol are enzymatically co-polymerized in solution via a two-stage method, using Candida antarctica Lipase B (CALB, in immobilized form as Novozyme® 435) as the biocatalyst. The chemical structures of the obtained products, poly(butylene succinate) (PBS) and poly(butylene succinate-co-itaconate) (PBSI), are confirmed by 1H- and 13C-NMR. The effects of the reaction conditions on the CALB-catalyzed synthesis of PBSI are fully investigated, and the optimal polymerization conditions are obtained. With the established method, PBSI with tunable compositions and satisfying reaction yields is produced. The 1H-NMR resul