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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

Tapered, Tubular Polyester Fabric.  

National Technical Information Service (NTIS)

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 war...

D. J. E. Lapointe L. T. Wright L. J. Vincent

1987-01-01

3

Damages in Processed Polyester Blend Fabric.  

National Technical Information Service (NTIS)

Many mills have started manufacturing and processing polyester blend fabrics. A study was undertaken to collect information on good and defective packing in sorts produced by most of the mills. Data on good packing and seconds, fents and rags are given fo...

R. C. Shah R. K. Shah

1978-01-01

4

The performance of cotton–kapok fabric–polyester composites  

Microsoft Academic Search

Cotton–kapok fabric, at a ratio of 2:3, has been incorporated with unsaturated polyester resin in various fibre volume fractions. The fabric was also treated with 5% sodium hydroxide with the aim of improving fibre–matrix adhesion. A simple manual lay up technique was used in fabricating the composites. A hand operated hydraulic electrically heated press was used and the composites were

Leonard Y Mwaikambo; Elias T. N Bisanda

1999-01-01

5

Plasma treatment of polyester fabric to impart the water repellency property  

Microsoft Academic Search

Polyester fabric is treated with DCDMS solution by two methods: dipping the fabric directly in DCDMS solution for different intervals and dipping the fabric in DCDMS solution after its exposure into RF plasma chamber for different durations at optimized exposure power conditions. The physical properties of polyester fabric treated with DCDMS in the presence or absence of air plasma have

C. J. Jahagirdar; L. B. Tiwari

2007-01-01

6

Characterization of surface modified polyester fabric.  

PubMed

Woven polyethylene terephthalate (PET) fabric has been used in the construction of vascular grafts and sewing ring of prosthetic heart valves. In an effort to improve haemocompatibility and tissue response to PET fabric, a fluoropolymer, polyvinylidine fluoride (PVDF), was coated on PET fabric by dip coating technique. The coating was found to be uniform and no significant changes occurred on physical properties such as water permeability and burst strength. Cell culture cytotoxicity studies showed that coated PET was non-cytotoxic to L929 fibroblast cell lines. In vitro studies revealed that coating improved haemocompatibility of PET fabric material. Coating reduced platelet consumption of PET fabric by 50%. Upon surface modification leukocyte consumption of PET was reduced by 24%. About 60% reduction in partial thromboplastin time (PTT) observed when PET was coated with PVDF. Results of endothelial cell proliferation studies showed that surface coating did not have any substantial impact on cell proliferation. Overall results indicate that coating has potential to improve haemocompatibility of PET fabric without affecting its mechanical performance. PMID:18584122

Joseph, Roy; Shelma, R; Rajeev, A; Muraleedharan, C V

2009-12-01

7

Status and Prospects for Flame Resistant Polyester/Cellulose Blend Fabrics.  

National Technical Information Service (NTIS)

The report describes the status of flame retardant (FR) finished polyester/cotton and polyester/rayon blend fabrics. While these fabrics represent a large part of the present market, there exists presently no commercial FR treatment for them, though such ...

G. C. Tesoro

1973-01-01

8

Biocidal Polyester.  

National Technical Information Service (NTIS)

Polyester fabrics were modified by covalently linking heterocyclic moieties, which could be halogenated, to the surfaces of the polyester fabrics. Antimicrobial activity was introduced into the fabrics and fibers by exposure to a source of oxidative chlor...

C. Wei C. Winkelmann J. Kim J. Lin S. D. Worley

2002-01-01

9

Plasma treatment of polyester fabric to impart the water repellency property  

Microsoft Academic Search

Polyester fabric is treated with DCDMS solution by two methods: dipping the fabric directly in DCDMS solution for different\\u000a intervals and dipping the fabric in DCDMS solution after its exposure into RF plasma chamber for different durations at optimized\\u000a exposure power conditions. The physical properties of polyester fabric treated with DCDMS in the presence or absence of air\\u000a plasma have

C J Jahagirdar; L B Tiwari

2007-01-01

10

Changes in the Mechanical Properties and Fabric Handle of Polyester-fibre Fabrics Through the Finishing Stages  

Microsoft Academic Search

The basic mechanical properties and fabric handle of the polyester-fibre fabric called ‘Shingosen’ were pursued through the finishing stages by an objective-evaluation method developed by Kawabata and Niwa, using the KES-FB system. The effects of the finishing stages were clarified as follows. The polyester-fibre fabric is remarkably softened in all its mechanical properties and fabric handle by the stage of

Mitsuo Matsudaira; Masao Matsui

1992-01-01

11

Plasma treatment of polyester fabric to impart the water repellency property  

NASA Astrophysics Data System (ADS)

Polyester fabric is treated with DCDMS solution by two methods: dipping the fabric directly in DCDMS solution for different intervals and dipping the fabric in DCDMS solution after its exposure into RF plasma chamber for different durations at optimized exposure power conditions. The physical properties of polyester fabric treated with DCDMS in the presence or absence of air plasma have been compared with control fabric. Different characterization techniques like scanning electron microscope, attenuated total reflectance-IR and Dataflash 100 colour measurement spectrophotometer are used to assess the surface morphology, composition and change in colour parameters. Water repellency property of both untreated and modified polyester fabric is studied using AATCC test method 39 (1971). The effectiveness of the water repellency property of modified polyester fabric is checked by repeated washing up to ten cycles.

Jahagirdar, C. J.; Tiwari, L. B.

2007-04-01

12

44—THE WRINKLE-RECOVERY OF CARRIER-DYED WOOL–POLYESTER-FIBRE FABRICS  

Microsoft Academic Search

An investigation is described in which the reduction in wrinkle-recovery of wool–polyester-fibre fabrics caused by the use of carrier during dyeing was studied. Only the polyester-fibre component absorbed appreciable amounts of carrier, and the extent of the reduction in wrinkle-recovery depended on the type and amount of carrier retained in the polyester fibre after dyeing. The effectiveness of finishing treatments

R. L. Hayes; D. G. Phillips

1978-01-01

13

Fluorocarbon nano-coating of polyester fabrics by atmospheric air plasma with aerosol  

NASA Astrophysics Data System (ADS)

A fluorocarbon coating was deposited on polyester (PET) woven fabric using pulse discharge plasma treatment by injecting a fluoropolymer directly into the plasma dielectric barrier discharge. The objective of the treatment was to improve the hydrophobic properties as well as the repellent behaviour of the polyester fabric. Plasma treatment conditions were optimised to obtain optimal hydrophobic properties which were evaluated using water contact angle measurement as well as spray-test method at the polyester fabric surface. The study showed that adhesion of the fluoropolymer to the woven PET was greatly enhanced by the air plasma treatment. X-ray photoemission spectroscopy (XPS) analyses revealed chemical surface modifications occurring after the plasma treatments.

Leroux, F.; Campagne, C.; Perwuelz, A.; Gengembre, L.

2008-04-01

14

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

NASA Astrophysics Data System (ADS)

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

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

2008-01-01

15

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

16

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

PubMed

Plastics are increasingly being used for the fabrication of Lab-on-a-Chip devices due to the variety of beneficial material properties, affordable cost, and straightforward fabrication methods available from a range of different types of plastics. Rapid prototyping of polydimethylsiloxane (PDMS) devices has become a well-known process for the quick and easy fabrication of microfluidic devices in the research laboratory; however, PDMS is not always an appropriate material for every application. This paper describes the fabrication of thermoset polyester microfluidic devices and masters for hot embossing using replica molding techniques. Rapid prototyped PDMS molds are convienently used for the production of non-PDMS polymeric devices. The recessed features in the cast polyester can be bonded to a second polyester piece to form an enclosed microchannel. Thermoset polyester can withstand moderate amounts of pressure and elevated temperature; therefore, the cast polyester piece also can be used as a master for embossing polymethylmethacrylate (PMMA) microfluidic systems. Examples of enclosed polyester and PMMA microchannels are presented, and we discuss the electroosmotic properties of both types of channels, which are important for analytical applications such as capillary electrophoresis. PMID:15100767

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

2003-08-01

17

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

Microsoft Academic Search

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

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

2009-01-01

18

Optimization of process conditions for electroless copper plating on polyester fabric  

Microsoft Academic Search

The copper-coated polyester fabric can be used to prepare electromagnetic shielding materials. At present, electroless copper plating mainly using formaldehyde as the reducing agent. But the stability of the bath is poor and it is also volatile and toxic. Using hypophosphite as reducing agent has more advantages for its stability and the plating process does not release any toxic gases.

Wang Xiao-hong; Liu Jian-xiao; Feng Pei-zhong; Sun Zhi

2011-01-01

19

Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation  

NASA Astrophysics Data System (ADS)

This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of sbnd SO3H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

Kordoghli, Bessem; Khiari, Ramzi; Mhenni, Mohamed Farouk; Sakli, Faouzi; Belgacem, Mohamed Naceur

2012-10-01

20

Paraffin Wax Emulsion as Water Repellent for Cotton\\/Polyester Blended Fabric  

Microsoft Academic Search

Paraffin wax emulsion is prepared by emulsifying paraffin wax (PW) in water using stearic acid (SA) and triethanolamine (TEA) emulsifying system. A mother emulsion is prepared at different concentrations of PW (10.5—19.1%w\\/w) and SA (4.5—13%w\\/w) neutralized to different extents by TEA (25—100% degree of neutralization). Upon treating 50\\/50 cotton\\/polyester fabric with a padding solution containing 50 g\\/L of different mother

M. H. Abo-Shosha; Z. H. El-Hilw; A. A. Aly; A. Amr; Al Said I. El. Nagdy

2008-01-01

21

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

NASA Astrophysics Data System (ADS)

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

Zohdy, Maged H.

2005-06-01

22

Surface Modification of Polyester Fabric by Non-Thermal Plasma Treatment  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

23

Fabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner electrophoresis microchips.  

PubMed

In this report, we describe the microfabrication and integration of planar electrodes for contactless conductivity detection on polyester-toner (PT) electrophoresis microchips using toner masks. Planar electrodes were fabricated by three simple steps: (i) drawing and laser-printing the electrode geometry on polyester films, (ii) sputtering deposition onto substrates, and (iii) removal of toner layer by a lift-off process. The polyester film with anchored electrodes was integrated to PT electrophoresis microchannels by lamination at 120 degrees C in less than 1 min. The electrodes were designed in an antiparallel configuration with 750 microm width and 750 microm gap between them. The best results were recorded with a frequency of 400 kHz and 10 Vpp using a sinusoidal wave. The analytical performance of the proposed microchip was evaluated by electrophoretic separation of potassium, sodium and lithium in 150 microm wide x 6 microm deep microchannels. Under an electric field of 250 V/cm the analytes were successfully separated in less than 90 s with efficiencies ranging from 7000 to 13,000 plates. The detection limits (S/N = 3) found for K+, Na+, and Li+ were 3.1, 4.3, and 7.2 micromol/L, respectively. Besides the low-cost and instrumental simplicity, the integrated PT chip eliminates the problem of manual alignment and gluing of the electrodes, permitting more robustness and better reproducibility, therefore, more suitable for mass production of electrophoresis microchips. PMID:18446805

Coltro, Wendell Karlos Tomazelli; da Silva, José Alberto Fracassi; Carrilho, Emanuel

2008-06-01

24

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

25

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

PubMed

Adjusting the mechanical properties of polyester-based vascular grafts is crucial to achieving long-term success in vivo. Although previous studies using a fabric-based approach have achieved some success, a central issue with pure poly(lactic acid) (PLA) or poly(glycolic acid) (PGA) grafts sealed with poly(dl-caprolactone-co-lactic acid) (P(CL/LA)) has been stenosis. Intimal hyperplasia, a leading cause of stenosis, can be caused by the mechanical incompatibility of synthetic vascular grafts. Investigating the performance of poly(glycolic-co-lactic acid) (PGLA) grafts could lead to insight into whether graft stenosis stems from mechanical issues such as noncompliance and unfavorable degradation times. This could be achieved by examining grafts with tunable mechanical properties between the ranges of such properties in pure PGA and PLA-based grafts. In this study, we examined PGLA-based grafts sealed with different P(CL/LA) solutions to determine the PGLA-P(CL/LA) grafts' mechanical properties and tissue functionality. Cell attachment and proliferation on graft surfaces were also observed. For in vivo assessment, grafts were implanted in a mouse model. Mechanical properties and degradation times appeared adequate compared to recorded values of vessels used in autograft procedures. Initial neotissue formation was observed in the grafts and patency maintained during the pilot study. This study presents a ?1-mm diameter degradable graft demonstrating suitable mechanical properties and in vivo pilot study success, enabling further investigation into the tuning of mechanical properties to reduce complications in degradable polyester fabric-based vascular grafts. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1972-1981, 2014. PMID:23852776

Melchiorri, Anthony J; Hibino, Narutoshi; Brandes, Zachary R; Jonas, Richard A; Fisher, John P

2014-06-01

26

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

PubMed

Biomimetic scaffolds that replicate the native architecture and mechanical properties of target tissues have been recently shown to be a very promising strategy to guide cellular growth and facilitate tissue regeneration. In this study, porous, soft, and elastic crosslinked urethane-doped polyester (CUPE) tissue engineered nerve guides were fabricated with multiple longitudinally oriented channels and an external non-porous sheath to mimic the native endoneurial microtubular and epineurium structure, respectively. The fabrication technique described herein is highly adaptable and allows for fine control over the resulting nerve guide architecture in terms of channel number, channel diameter, porosity, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers and displayed an ultimate peak stress of 1.38 ± 0.22 MPa with a corresponding elongation at break of 122.76 ± 42.17%, which were comparable to that of native nerve tissue. The CUPE nerve guides were also evaluated in vivo for the repair of a 1 cm rat sciatic nerve defect. Although histological evaluations revealed collapse of the inner structure from CUPE TENGs, the CUPE nerve guides displayed fiber populations and densities comparable with nerve autograft controls after 8 weeks of implantation. These studies are the first report of a CUPE-based biomimetic multichanneled nerve guide and warrant future studies towards optimization of the channel geometry for use in neural tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2793-2804, 2014. PMID:24115502

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

2014-08-01

27

Different plasma-based strategies to improve the interaction of anionic dyes with polyester fabrics surface  

NASA Astrophysics Data System (ADS)

Low-pressure plasma treatments with subsequent immobilization of functional macromolecules from aqueous solution have gained an increasing popularity for its applications in new industrial processes. In this work, two different strategies to endow polyester fabrics (PET) with accessible primary amino groups are compared. (a) NH2 groups were produced directly using low-pressure ammonia plasma. (b) Negatively charged groups were introduced by low-pressure oxygen plasma to hydrophilize the fabric surfaces and used as anchor groups for the immobilization of water-borne polyelectrolyte copolymers poly(vinyl amine-co-vinyl amide) (PVAm). To study the effects of these surface modifications, a combination of various surface-sensitive characterization techniques such as X-ray photoelectron spectroscopy (XPS), streaming potential measurements and time-dependent contact angle measurements were used. Furthermore, the influence of the pre-treatments on the interaction of PET fabrics with water-soluble dyes was evaluated. For that purpose, color strength and fastness tests were carried out to prove the effectiveness of pre-treatments.

Salem, Tarek; Pleul, Dieter; Nitschke, Mirko; Müller, Martin; Simon, Frank

2013-01-01

28

Biodegradable and injectable paclitaxel-loaded poly(ester amide)s microspheres: fabrication and characterization.  

PubMed

Novel biodegradable submicron microspheres of amino acid based poly(ester amide)s (PEAs) were fabricated by an oil-in-water (O/W) emulsion/solvent evaporation technique and their morphology and drug loading efficiency were examined. PEAs microspheres of mean diameter <1 microm with very narrow size distribution were obtained at a fair yield about 80%. The effects of PEA polymer concentration, polyvinyl alcohol emulsifier concentration, and the homogenizer speed on the size and morphology of final PEA microspheres were examined by analyzing their SEM images. It is found that a low PEA concentration, a high PVA concentration, and a high homogenizer speed are the optimal conditions for obtaining smaller microspheres. The biodegradation behaviors of these PEA microspheres at 37 degrees C were investigated as a function of enzyme (alpha-chymotrypsin) concentration and incubation time. The data showed similar surface erosion degradation mechanism as PEA polymers reported previously. Paclitaxel loaded PEA microspheres with high encapsulation efficiency were obtained without significantly affecting their size and surface morphology. The high drug loading efficiency close to 100% suggested that PEA microspheres may have the potential for the injection administration of highly hydrophobic anticancer drugs. PMID:18937264

Guo, Kai; Chu, C C

2009-05-01

29

Study on biodegradability of terephthalic acid in polyester fabric alkali-peeling process wastewater.  

PubMed

Terephthalic acid (TA) and ethylene glycol (EG) are the main pollutants in polyester fabric alkali-peeling process wastewater (PAP-wastewater). The biodegradability of TA is crucial to the deep treatment of PAP-wastewater. Batch and continuous experiments were adopted to study the biodegradation of TA in synthetic wastewater. In anoxic batch experiments TA began to degrade gradually after EG was depleted completely. However, in aerobic batch experiments the biodegradation curves of TA in the presence of EG were almost identical to those of TA in the absence of EG. The combined process of anoxic hydrolysis-acidification bioreactor (HABR) and aerobic hybrid membrane bioreactor (HMBR) was employed to treat synthetic PAP-wastewater in continuous experiments. When TA was fed as sole substrate, about 6.1% was removed in the anoxic HABR and 92.1% was biodegraded in the aerobic HMBR. When TA and EG were fed as substrate, only 1.9% of TA was biodegraded in the anoxic HABR and 96.6% of TA was removed in the aerobic HMBR. By contrast, most EG was removed in the anoxic HABR. The experimental results revealed that the combined process of anoxic HABR and aerobic HMBR was an attractive alternative for the treatment of PAP-wastewater and other similar wastewater. PMID:24473302

Yang, Qiyong; Wu, Zhongwei; Tao, Chunyuan

2014-01-01

30

An investigation into the properties of cotton\\/spandex and polyester\\/spandex knitted fabrics  

Microsoft Academic Search

Very little work has been done in the area of spandex-blend weft knits. This paper presents the findings of knits produced from cotton\\/spandex- and polyester\\/spandex-blend knits produced from core spun yarns. The dimensional properties of cotton\\/spandex knits compare well with those of cotton knits. The behaviour of the loops in both the spandexblend knits in the course direction gives rise

N. Gokarneshan; K. Thangamani

2010-01-01

31

Application of nanometal oxides in situ in nonwoven polyester fabric for the removal of bacterial indicators of pollution from wastewater.  

PubMed

The objective of this study is to investigate and assess the use of in situ deposit nanosilver (nAg2O) or nanocopper oxides (nCuO) into nonwoven polyester fabric (NWPF) as a safe and effective antibacterial filter of pollution from domestic wastewater. The bactericidal effect of both nAg2O and nCuO was examined against Gram-negative bacteria (Escherichia coli, Salmonella typhi) and Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus) using agar diffusion disk method. In addition, the capability of nAg2O and nCuO as disinfectants for secondary treated domestic wastewater was investigated as a case study. Transmission electron microscope (TEM) confirmed the formation of nAg2O and nCuO particles with average particle sizes of 15 and 41 nm, respectively. Disk diffusion results showed that nAg2O had a higher bactericidal effect than nCuO. Moreover, the disinfection of secondary treated wastewater using 1.27 mg/cm(3) of nAg2O in the nonwoven fabric was capable of hindering 99.6% and 91.7% of total and fecal coliforms within 10 minutes with a residual value of 18 and 15 MPN-index/100 mL, respectively. The residual total and fecal coliform concentrations were far less than that stated in the national and international limits for wastewater reuse in agriculture purpose. PMID:24672400

Abou-Elela, Sohair I; Ibrahim, Hanan S; Kamel, Mohamed M; Gouda, Mohamed

2014-01-01

32

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

33

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

34

Development of superhydrophilic and superhydrophobic polyester fabric by growing zinc oxide nanorods.  

PubMed

ZnO nanorods were grown on microfibers of Polyethylene terephthalate (PET) fabric by seeding method to develop hierarchical roughness structure. XRD and XPS analysis show the presence of crystalline ZnO and chemical Zn species at the fiber surface at each stage of the process. Five series of samples with different seed concentrations have been realized, and their surface morphology and topography were characterized by AFM and SEM. Increasing seed concentrations lead to samples with superhydrophilic properties. Not only the water contact angle at fabric surface tends to zero but also the water capillary diffusion inside fabric is faster. Nanostructuration affects the structure inside the fabric, and further experiments with decane liquid have been made to get a better understanding of this effect. To study the superhydrophobicity, nanorods treated samples were modified with octadecyltrimethoxysilane (ODS) by two method; solution deposition and vapor deposition. The superhydrophobicity was characterized by measuring the water contact angle and water sliding angle with 5 ?l water droplet. The samples modified with ODS by vapor deposition showed higher water contact angles and low water sliding angle than the ones modified with solution method. The lotus effect has been well correlated with the surface morphology of the nanorods structured fibers. The application of the Cassie-Baxter equation is discussed. PMID:23261128

Ashraf, Munir; Campagne, Christine; Perwuelz, Anne; Champagne, Philippe; Leriche, Anne; Courtois, Christian

2013-03-15

35

Effects of siloxane plasma coating on the frictional properties of polyester and polyamide fabrics  

Microsoft Academic Search

Hydrophobic siloxane plasma coatings (pp-HMDSO) were deposited on flexible polymeric substrates in order to investigate their performance within different tribo systems. The frictional properties of plasma-coated foils and fabrics were thus examined using the Textile Friction Analyzer. The friction measurements were realized under dry, wet and saturated conditions to simulate sweating during running and using two different tribo-partners (i.e. steel

E. Bertaux; E. Le Marec; D. Crespy; R. Rossi; D. Hegemann

2009-01-01

36

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

SciTech Connect

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

Lewak, R.J.

1990-01-01

37

Small diameter Polyurethane vascular graft reinforced by elastic weft-knitted tubular fabric of polyester\\/spandex  

Microsoft Academic Search

Small diameter vascular grafts were fabricated from pure Polyurethane (PU) as well as PU reinforced with a tubular weft-knitted\\u000a fabric. The tensile properties of the reinforced composite vascular grafts were compared with that of the tubular fabric itself\\u000a and the pure PU vascular grafts. The elasticity and strength of the reinforced vascular grafts were improved compared with\\u000a the tubular fabric.

Weilin Xu; Fei Zhou; Chenxi Ouyang; Weigang Cui; Mu Yao; Xungai Wang

2008-01-01

38

Liquid Crystal Polyester Thermosets.  

National Technical Information Service (NTIS)

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 materi...

B. C. Benicewicz A. E. Hoyt

1990-01-01

39

Liquid crystal polyester thermosets.  

National Technical Information Service (NTIS)

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 materi...

B. C. Benicewicz A. E. Hoyt

1990-01-01

40

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

Microsoft Academic Search

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

Choon Gil Lee

2006-01-01

41

One-pot synthesis of disperse dyes under microwave irradiation: dyebath reuse in dyeing of polyester fabrics.  

PubMed

A series of 4-hydroxyphenylazopyrazolopyrimidine disperse dyes were prepared via one-pot reactions of p-hydroxyphenylhydrazone, hydrazine hydrate, and acetylacetone or enaminones using microwave irradiation as an energy source. Structural assignments of the dyes were confirmed by X-ray crystallographic structure determination. Instead of discharging the dyebath after each dyeing cycle, the residual dyebath was spectrophotometrically analyzed and then pH readjusted for a repeat dyeing with longer time. Fastness of the dyed samples was measured after each recycle. Most of the dyed fabrics tested displayed good light fastness and excellent fastness to washing and perspiration. Finally, the biological activity of the synthesized dyes against Gram positive bacteria, Gram negative bacteria and yeast were evaluated. PMID:22491676

Al-Etaibi, Alya M; El-Apasery, Morsy A; Mahmoud, Huda M; Al-Awadi, Nouria A

2012-01-01

42

Scaffold for tissue engineering fabricated by non-isothermal supercritical carbon dioxide foaming of a highly crystalline polyester.  

PubMed

Porous scaffolds of a random co-polymer of omega-pentadecalactone (PDL) and epsilon-caprolactone (CL) (poly(PDL-CL)), synthesized by biocatalysis, were fabricated by supercritical carbon dioxide (scCO(2)) foaming. The co-polymer, containing 31 mol.% CL units, is highly crystalline (T(m) = 82 degrees C, DeltaH(m) = 105 J g(-1)) thanks to the ability of the two monomer units to co-crystallize. The co-polymer can be successfully foamed upon homogeneous absorption of scCO(2) at T > T(m). The effect of soaking time, depressurization rate and cooling rate on scaffold porosity, pore size distribution and pore interconnectivity was investigated by micro X-ray computed tomography. Scaffolds with a porosity in the range 42-76% and an average pore size of 100-375 microm were successfully obtained by adjusting the main foaming parameters. Process conditions in the range investigated did not affect the degree of crystallinity of poly(PDL-CL) scaffolds. A preliminary study of the mechanical properties of the scaffolds revealed that poly(PDL-CL) foams may find application in the regeneration of cartilage tissue. PMID:19619678

Gualandi, Chiara; White, Lisa J; Chen, Liu; Gross, Richard A; Shakesheff, Kevin M; Howdle, Steven M; Scandola, Mariastella

2010-01-01

43

Naturally Occurring Polyesters  

Microsoft Academic Search

MAY I add to the recent note1 on the isolation of a natural elastic polyester2? The natural occurrence of polyesters was observed as early as 1908 by Boug-ault and Bourdier3, who showed that the waxes obtained by extraction of the leaves of a variety of conifers are linear polyesters of hydroxy-acids such as juniperic acid (omega-hydroxypalmitic acid) and sabinic acid

F. S. Spring

1945-01-01

44

Elastomers Based on Polyester  

Microsoft Academic Search

Polyester elastomers were prepared by block copolymerization of dimethyl terephthalate (DMT), butanediol (BDO), and polytetramethylene glycol (PTMG). Polyester from DMT and butanediol forms a high-melting hard segment in block copolyester to prevent undue chain slippage when fibers are stretched. High elongation was provided by soft segment which consisted of condensation product from DMT and PTMG.Experiments were carried out to determine

A. A. Nishimura; H. Komagata

1967-01-01

45

Kapok\\/cotton fabric–polypropylene composites  

Microsoft Academic Search

Kapok\\/cotton fabric has been used as reinforcement for conventional polypropylene and maleic anhydride grafted polypropylene resins. Treating the reinforcement with acetic anhydride and sodium hydroxide has modified the fabric (fibres). Thermal and mechanical properties of the composites were investigated. Results show that fibre modification gives a significant improvement to the thermal properties of the plant fibres, whereas tests on the

Leonard Y Mwaikambo; Ezio Martuscelli; Maurizio Avella

2000-01-01

46

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

47

Determination of the heatsetting temperature of polyester by TMA  

Microsoft Academic Search

The determination of the effective temperature of the thermal treatment applied to polyester substrates in the textile process\\u000a has been broadly studied by differential scanning calorimetry (DSC). In this investigation, the authors have studied the possibilities\\u000a of the thermomechanical analysis (TMA) as a method for the determination of this temperature. For this purpose, fabrics of\\u000a polyester heatset in an industrial

D. Cayuela; A. M. Manich; I. Gacén; J. Gacén

2003-01-01

48

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

49

Resisting protein adsorption on biodegradable polyester brushes.  

PubMed

The protein adsorption and degradation behaviors of poly(lactic acid), poly(glycolic acid) (PGA) and poly(?-caprolactone) (PCL) brushes and their co-polymer brushes with oligo(ethylene glycol) (OEG) were studied. Both brush structure and relative amount of OEG and polyester were found to be important to the protein resistance of the brushes. A protein-resisting surface can be fabricated either by using OEG as the top layer of a copolymer brush or by increasing the amount of OEG relative to polyester when using a hydroxyl terminated OEG (OEG-OH) and a methoxy terminated OEG (OEG-OMe) mixture as the substrate layer. The degradation of single polyester brushes and their co-polymer brushes using OEG-OH as a substrate layer or using OEG as a top layer was hindered. This phenomenon was rationalized by the inhibition of the proposed back-biting process as the hydroxy end groups of polyester were blocked by OEG molecules. Among these brushes tested, PGA co-polymer brushes using the methoxy/hydroxyl OEG mixture as the substrate layer proved to be both protein-resistant and degradable due to the relatively large amount of OEG moieties and the good biodegradability of PGA. PMID:24802301

Hu, Xinfang; Gorman, Christopher B

2014-08-01

50

Synthese, caracterisation et applications de polyesters derives d'oligothiophenes  

NASA Astrophysics Data System (ADS)

Le travail presente ici a pour but de synthetiser des polyesters derives d'oligothiophenes utilisables dans des diodes electroluminescentes et des dispositifs optiques non-lineaires. Differents polyesters derives d'oligothiophenes (de une a six unites) ont ete synthetises par polycondensation en masse. Trois groupes espaceurs ont ete utilises: le 1, 10-decanediol, le 1,6-hexanediol et l'hexaethyleneglycol. La structure chimique des polyesters a ete etudiee entre autres, par spectroscopie RMN. Cette technique a montre que les polyesters avaient une structure parfaitement alternee. Les proprietes optiques de ces polyesters ont montre que cette famille de polyesters pouvait emettre sur une large gamme du spectre du visible, ce qui en fait de bons candidats pour les diodes electroluminescentes. En outre, a partir de quatre unites thiophene les polyesters ont montre une certaine electroactivite. Les polyesters avec cinq et six unites thiophene ont, de plus, la capacite d'etre reduits et les mesures de conductivite in-situ ont montre que les electrons et les trous sont transportes avec une efficacite comparable au sein du polymere. Enfin, les polyesters possedant un groupe espaceur hydrophile forment facilement des films par la technique de Langmuir-Blodgett. L'ensemble de ces proprietes a fait de ces polymeres de bons candidats pour la fabrication de diodes electroluminescentes a base de films Langmuir-Blodgett. Des resultats interessants ont ete obtenus avec les polyesters a base de derives du pentathiophene et du sexithiophene. Cependant, l'electroluminescence reste assez faible et une amelioration pourrait etre obtenue en utilisant des materiaux plus luminescents. Les proprietes non-lineaires de ces polyesters ont ete etudiees en solution par la technique du z-scan. Les valeurs de chi(3) extrapolees a un film mince sont tres superieures a celles obtenues avec des poly(3-alkylthiophenes) (10-9 esu vs 10 -12 esu, respectivement). Cette augmentation a ete attribuee au fait que la longueur de conjugaison est constante dans les polyesters et a l'etroitesse de la bande d'absorption. L'orientation des polyesters pourrait etre une voie prometteuse pour l'amelioration des proprietes non-lineaires.

Donat-Bouillud, Anne

51

In vivo assessment of odour retention in an antimicrobial silver chloride-treated polyester textile  

Microsoft Academic Search

The purpose of this study was to determine whether polyester textiles treated with bioactive concentrations of an antimicrobial silver chloride (SC) compound were effective in reducing axillary odour and axillary bacterial populations before and after multiple washes. A polyester knit fabric was treated with two concentrations of a SC formulation (resulting in 30 and 60?ppm of silver) and evaluated at

Rachel H. McQueen; Monika Keelan; Yin Xu; Tannie Mah

2012-01-01

52

Stabilized Unsaturated Polyesters.  

National Technical Information Service (NTIS)

An unsaturated polyester, such as propylene glycol-maleic acid-phtatic acid prepolymer dissolved in styrene is interpolymerized with an ultraviolet absorber and/or an antioxidant to form a polymer stable to exposure to the outdoors without degradation by ...

E. Borsig O. Vogl

1984-01-01

53

Identification of a keratinase-producing bacterial strain and enzymatic study for its improvement on shrink resistance and tensile strength of wool- and polyester-blended fabric.  

PubMed

A wool-degrading bacterium was isolated from decomposition wool fabrics in China. The strain, named 3096-4, showed excellent capability of removing cuticle layer of wool fibers, as demonstrated by removing cuticle layer completely within 48 h. According to the phenotypic characteristics and 16S rRNA profile, the isolate was classified as Pseudomonas. Bacteria growth and keratinase activity of the isolate were determined during cultivation on raw wool at different temperatures, initial pH, and rotation speed using orthogonal matrix method. Maximum growth and keratinase activity of the bacterium were observed under the condition including 30 °C, initial pH 7.6, and rotational speeds 160 rpm. The keratinase-containing crude enzyme prepared from 3096-4 was evaluated in the treatment of wool fabrics. The optimal condition of our enzymatic improvement of shrink resistance was the combination of 30 °C, initial pH 7.6, and rotation speeds 160 rpm. After the optimized treatment, the wool fabrics felting shrink was 4.1% at 6 h, and textile strength was not lost. PMID:20607444

Cai, Shao-Bo; Huang, Zheng-Hua; Zhang, Xing-Qun; Cao, Zhang-Jun; Zhou, Mei-Hua; Hong, Feng

2011-01-01

54

Microfabricated polyester conical microwells for cell culture applications.  

PubMed

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?, Seila; Piraino, Francesco; Bae, Hojae; Rasponi, Marco; Redaelli, Alberto; Khademhosseini, Ali

2011-07-21

55

21 CFR 177.1590 - Polyester elastomers.  

Code of Federal Regulations, 2010 CFR

...3 2009-04-01 2009-04-01 false Polyester elastomers. 177.1590 Section 177.1590...Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester elastomers identified in paragraph...

2009-04-01

56

21 CFR 177.1590 - Polyester elastomers.  

Code of Federal Regulations, 2010 CFR

... 3 2010-01-01 2009-04-01 true Polyester elastomers. 177.1590 Section 177.1590...Repeated Use Food Contact Surfaces § 177.1590 Polyester elastomers. The polyester elastomers identified in paragraph...

2010-01-01

57

Summary of Laboratory and Field Comfort Studies on Candidate Fabrics for a Year-Round Uniform.  

National Technical Information Service (NTIS)

The program objective was to choose a year-round uniform from three candidate fabrics to replace the two uniforms (lightweight 50/50 polyester/cotton and 55/45 polyester/wool tropical) currently in use. The candidate fabrics were 55/45 polyester/wool, and...

M. O. Parker N. R. Hollies

1986-01-01

58

Liquid crystal polyester thermosets  

SciTech Connect

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

59

Biodegradable aliphatic polyester ionomers.  

PubMed

A series of polyester-based ionomers containing dimethyl 5-sulfoisophthalate sodium salt (DMSI) with up to 5 mol-% diacid units was synthesized by two-step polycondensation. Furthermore a polylactic acid (PLA) was modified by introducing poly(ethylene-co-methacrylic acid) ionomers with different ion groups, such as Na, Li, and Zn, using the melt blending method. This review examines the effect of the ionic group on the dynamic mechanical properties, melt rheology, crystallization behavior, degradation behavior, and biocompatibility with human dermal cells, as well as the nucleating effect of poly(ethylene-co-methacrylic acid) ionomer in PLA. PMID:15468209

Han, Sang-Il; Yoo, Youngtai; Kim, Dong Kook; Im, Seung Soon

2004-03-15

60

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

61

Control Techniques for Organic Gas Emissions from Fiberglass Impregnation and Fabrication Processes.  

National Technical Information Service (NTIS)

A statewide inventory of air polluting styrene emissions from manufacturing plants processing or fabricating polyester resin-impregnated, glass fiber-reinforced products has been conducted for California. A total of 305 users of unsaturated polyester resi...

M. B. Rogozen

1982-01-01

62

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

63

Amperometric Cholesterol Biosensor Using Layer-By-layer Adsorption Technique onto Polyaniline-Coated Polyester Films  

Microsoft Academic Search

An amperometric cholesterol biosensor was fabricated using polyaniline-coated polyester films. Polyaniline was dissolved in chloroform with camphorsulfonic acid, and polystyrene was added in this solution. Using this mixed solution, the coating was performed onto polyester films. Cholesterol oxidase was immobilized onto these films using an electrostatic layer-by-layer adsorption technique. Poly(diallyldimethylammonium chloride) was used as the counter ion source. The level

Min Jae Shin; Jin Gon Kim; Jae Sup Shin

2012-01-01

64

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

65

Polyester ?-assay chip for stem cell studies  

PubMed Central

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

Piraino, Francesco; Selimovic, Seila; Adamo, Marco; Pero, Alessandro; Manoucheri, Sam; Bok Kim, Sang; Demarchi, Danilo; Khademhosseini, Ali

2012-01-01

66

Polyester ?-assay chip for stem cell studies.  

PubMed

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

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

2012-01-01

67

Biodegradable Polyester/Layered Silicate Nanocomposites.  

National Technical Information Service (NTIS)

Nanocomposites of alpha-hydroxy polyester, polylactide (PLA) and Beta-hydroxy polyester, polyhydroxybutyrate (PHB) with layered silicates have been successfully prepared by melt extrusion of PLA and PHB with organically modified montmorillonite (MMT) and ...

C. A. Batt E. P. Giannelis P. Maiti

2003-01-01

68

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

69

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

70

40 CFR 721.9507 - Polyester silane.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 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...

2009-07-01

71

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

72

Polyester synthases: natural catalysts for plastics.  

PubMed Central

Polyhydroxyalkanoates (PHAs) are biopolyesters composed of hydroxy fatty acids, which represent a complex class of storage polyesters. They are synthesized by a wide range of different Gram-positive and Gram-negative bacteria, as well as by some Archaea, and are deposited as insoluble cytoplasmic inclusions. Polyester synthases are the key enzymes of polyester biosynthesis and catalyse the conversion of (R)-hydroxyacyl-CoA thioesters to polyesters with the concomitant release of CoA. These soluble enzymes turn into amphipathic enzymes upon covalent catalysis of polyester-chain formation. A self-assembly process is initiated resulting in the formation of insoluble cytoplasmic inclusions with a phospholipid monolayer and covalently attached polyester synthases at the surface. Surface-attached polyester synthases show a marked increase in enzyme activity. These polyester synthases have only recently been biochemically characterized. An overview of these recent findings is provided. At present, 59 polyester synthase structural genes from 45 different bacteria have been cloned and the nucleotide sequences have been obtained. The multiple alignment of the primary structures of these polyester synthases show an overall identity of 8-96% with only eight strictly conserved amino acid residues. Polyester synthases can been assigned to four classes based on their substrate specificity and subunit composition. The current knowledge on the organization of the polyester synthase genes, and other genes encoding proteins related to PHA metabolism, is compiled. In addition, the primary structures of the 59 PHA synthases are aligned and analysed with respect to highly conserved amino acids, and biochemical features of polyester synthases are described. The proposed catalytic mechanism based on similarities to alpha/beta-hydrolases and mutational analysis is discussed. Different threading algorithms suggest that polyester synthases belong to the alpha/beta-hydrolase superfamily, with a conserved cysteine residue as catalytic nucleophile. This review provides a survey of the known biochemical features of these unique enzymes and their proposed catalytic mechanism.

Rehm, Bernd H A

2003-01-01

73

Photodegradable Polyesters for Triggered Release  

PubMed Central

Photodegradable polyesters were synthesized with a photolabile monomer 2-nitrophenylethylene glycol and dioyl chlorides with different lengths. These polymers can be assembled to form polymeric particles with encapsulation of target substances. Light activation can degrade these particles and release payloads in both aqueous solutions and RAW 264.7 cells.

Lv, Cong; Wang, Zhen; Wang, Peng; Tang, Xinjing

2012-01-01

74

Amperometric glucose biosensor by means of electrostatic layer-by-layer adsorption onto polyaniline-coated polyester films  

Microsoft Academic Search

An amperometric glucose biosensor was fabricated using polyaniline-coated polyester films. Polyaniline was reacted with camphorsulfonic acid to produce a salt, which was then dissolved in chloroform containing polystyrene. Using this solution, the coating was performed onto polyester films. Glucose oxidase was immobilized onto these films using an electrostatic layer-by-layer adsorption technique. In this method, poly(diallyldimethylammonium chloride) was used as the

Young Jae Shin; Sun Hee Kim; Do Hyeon Yang; Hyoshik Kwon; Jae Sup Shin

2010-01-01

75

21 CFR 177.2420 - Polyester resins, cross-linked.  

Code of Federal Regulations, 2010 CFR

...exceed 0.2 percent of the polyester resin. 4. Solvents for... Asbestos Glass fiber Polyester fiber produced by the condensation...glycol 6000 Silicon dioxide Wax, petroleum Complying with... (c) The cross-linked polyester resins, with or...

2010-01-01

76

21 CFR 177.2420 - Polyester resins, cross-linked.  

Code of Federal Regulations, 2010 CFR

...exceed 0.2 percent of the polyester resin. 4. Solvents for... Asbestos Glass fiber Polyester fiber produced by the condensation...glycol 6000 Silicon dioxide Wax, petroleum Complying with... (c) The cross-linked polyester resins, with or...

2009-04-01

77

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Polyester polyurethane acrylate. 721.8082 Section 721...Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance...identified generically as polyester polyurethane acrylate (PMN P-93-498)...

2013-07-01

78

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Polyester polyurethane acrylate. 721.8082...Chemical Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical...chemical substance identified generically as polyester polyurethane acrylate (PMN...

2009-07-01

79

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

80

40 CFR 721.8082 - Polyester polyurethane acrylate.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Polyester polyurethane acrylate. 721.8082 Section... § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance...generically as polyester polyurethane acrylate (PMN P-93-498)...

2010-07-01

81

Synthesis, characterization and mechanical properties of polyester-based aliphatic polyurethane elastomers containing hyperbranched polyester segments  

Microsoft Academic Search

Aliphatic polyester-based polyurethane (PU) elastomers with hyperbranched polyester segments were synthesized from polyester diol, hydroxyl-terminated hyperbranched polyester (HB-20), isophorone diisocyanate (PDI) and 1,4-butanediol. The crosslinking density of the PU elastomer was calculated by using Flory–Rehner equation. The degree of hydrogen bonding, the microstructure and the morphologies of these PU materials were characterized by means of FT-IR, WAXD and DSC, respectively.

Jie Zhang; Chun Pu Hu

2008-01-01

82

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...

83

Cornea engineering on polyester carriers.  

PubMed

In this study, biodegradable polyester based carriers were designed for tissue engineering of the epithelial and the stromal layers of the cornea, and the final construct was tested in vitro. In the construction of the epithelial layer, micropatterned films were prepared from blends of biodegradable and biocompatible polyesters of natural (PHBV) and synthetic (P(L/DL)LA) origin, and these films were seeded with D407 (retinal pigment epithelial) cells. To improve cell adhesion and growth, the films were coated with fibronectin. To serve as the stromal layer of the cornea, highly porous foams of P(L/DL)LA-PHBV blends were seeded with 3T3 fibroblasts. Cell numbers on the polyester carriers were significantly higher than those on the tissue culture polystyrene control. The cells and the carriers were characterized scanning electron micrographs showed that the foam was highly porous and the pores were interconnected. 3T3 Fibroblasts were distributed quite homogeneously at the seeding site, but probably because of the high thickness of the carrier ( approximately 6 mm); they could not sufficiently populate the core (central parts of the foam) during the test duration. The D407 cells formed multilayers on the micropatterned polyester film. Immunohistochemical studies showed that the cells retained their phenotype during culturing; D407 cells formed tight junctions characteristic of epithelial cells, and 3T3 cells deposited collagen type I into the foams. On the basis of these results, we concluded that the micropatterned films and the foams made of P(L/DL)LA-PHBV blends have a serious potential as tissue engineering carriers for the reconstruction of the epithelial and stromal layers of the cornea. PMID:16758462

Zorlutuna, P; Tezcaner, A; Kiyat, I; Aydinli, A; Hasirci, V

2006-10-01

84

Dielectric relaxations in aliphatic polyesters  

NASA Astrophysics Data System (ADS)

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

Sen, Sudeepto

2001-07-01

85

Fiber Reinforced Polyester Resins Polymerized by Microwave Source  

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

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

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

88

Dielectric Properties of Polymer Matrix Composites Prepared from Conductive Polymer Treated Fabrics.  

National Technical Information Service (NTIS)

The dielectric functions of polypyrrole-treated polyester fabric and polypyrrole-treated S-glass fabric in polyester resin matrix composites have been calculated from free-space reflectance data in the 26.5 GHz to 40 GHz range. The data indicate that for ...

L. C. Sengupta W. A. Spurgeon

1992-01-01

89

Preparation and characterisation of polyurethane coatings based on polyester polyol  

Microsoft Academic Search

Purpose – The purpose of this paper is to describe how to synthesise polyurethane resins by using different polyester polyols and HDI isocyanurate. The polyester polyols were prepared by reacting single diol with different diacids. The effects of these polyester polyols on the performance properties of the coating films are studied. Design\\/methodology\\/approach – A series of hydroxyl-terminated polyester polyols were

S. Awasthi; D. Agarwal

2010-01-01

90

Heat-shrinkable polyester films  

US Patent & Trademark Office Database

Heat-shrinkable polyester films suitable for label use, wherein the value of tan .delta. for dynamic viscoelasticity in a main shrinkage direction of the film is 0.15 or higher at 65.degree. C. and takes a maximum of 0.40 or higher at a temperature of 65.degree. C. to 100.degree. C. both inclusive, and the heat shrinkability in the main shrinkage direction of the film after treatment in hot water at 80.degree. C. for 10 seconds is 30% or higher, have excellent shrinkage characteristics over a wide range of temperature extending from low temperatures to high temperatures, particularly in the low temperature range, which may cause only rare occurrence of shrinkage spots, wrinkles, strains, longitudinal sinking, and other defects during heat shrinkage, and which may further have excellent break resistance.

2002-01-29

91

Mechanical Properties of Unsaturated Polyester / Montmorillonite Composites.  

National Technical Information Service (NTIS)

Nanocomposites composed of unsaturated polyester matrix and organically modified clay filler were prepared. After the synthesis, XRD patterns showed that the interlayer spacing expanded from 1.25 nm to 4.5 nm. The mechanical properties of the nanocomposit...

A. B. Inceogul U. Yilmazer

2001-01-01

92

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

NASA Astrophysics Data System (ADS)

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

Cao, Xia

93

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...

94

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

95

High quality plasma enhanced chemical vapour deposited silicon oxide gas barrier coatings on polyester films  

Microsoft Academic Search

Silicon oxide barrier coatings fabricated by a plasma enhanced chemical vapour deposition roll-to-roll process on polyester film have demonstrated impressive properties as a barrier to water vapour permeation. This study highlights the influence of the substrate on these coatings as we find that heat stabilised poly(ethylene terephthalate) (PET), with or without an additional acrylate primer layer, and poly(ethylene naphthalate) (PEN)

D. G. Howells; B. M. Henry; J. Madocks; H. E. Assender

2008-01-01

96

Synthetic polyester from algae oil.  

PubMed

Current efforts to technically use microalgae focus on the generation of fuels with a molecular structure identical to crude oil based products. Here we suggest a different approach for the utilization of algae by translating the unique molecular structures of algae oil fatty acids into higher value chemical intermediates and materials. A crude extract from a microalga, the diatom Phaeodactylum tricornutum, was obtained as a multicomponent mixture containing amongst others unsaturated fatty acid (16:1, 18:1, and 20:5) phosphocholine triglycerides. Exposure of this crude algae oil to CO and methanol with the known catalyst precursor [{1,2-(tBu2 PCH2 )2 C6 H4 }Pd(OTf)](OTf) resulted in isomerization/methoxycarbonylation of the unsaturated fatty acids into a mixture of linear 1,17- and 1,19-diesters in high purity (>99?%). Polycondensation with a mixture of the corresponding diols yielded a novel mixed polyester-17/19.17/19 with an advantageously high melting and crystallization temperature. PMID:24845347

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

2014-06-23

97

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 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...

2009-07-01

98

21 CFR 177.2420 - Polyester resins, cross-linked.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Polyester resins, cross-linked. 177.2420 Section...for Repeated Use § 177.2420 Polyester resins, cross-linked. Cross-linked polyester resins may be safely used as articles or...

2011-04-01

99

21 CFR 177.2420 - Polyester resins, cross-linked.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Polyester resins, cross-linked. 177.2420 Section...for Repeated Use § 177.2420 Polyester resins, cross-linked. Cross-linked polyester resins may be safely used as articles or...

2012-04-01

100

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.

Draper, Jenny L.; Rehm, Bernd H.

2012-01-01

101

(Citric acid-co-polycaprolactone triol) polyester  

PubMed Central

Tissue engineering holds enormous challenges for materials science, wherein the ideal scaffold to be used is expected to be biocompatible, biodegradable and possess mechanical and physical properties that are suitable for target application. In this context, we have prepared degradable polyesters in different ratios by a simple polycondensation technique with citric acid and polycaprolactone triol. Differential scanning calorimetry indicated that the materials were amorphous based the absence of a crystalline melting peak and the presence of a glass transition temperature below 37°C. These polyesters were found to be hydrophilic and could be tailor-made into tubes and films. Porosity could also be introduced by addition of porogens. All the materials were non-cytotoxic in an in vitro cytotoxicity assay and may degrade via hydrolysis to non-toxic degradation products. These polyesters have potential implications in the field of soft tissue engineering on account of their similarity of properties.

Thomas, Lynda V.; Nair, Prabha D.

2011-01-01

102

Influence of surface treatment on the electroless nickel plating of textile fabric  

NASA Astrophysics Data System (ADS)

The present study is performed with an objective to acquire a deeper understanding of the properties of nickel-plated polyester fabric after conducing low temperature plasma treatment. Low temperature plasma treatment with oxygen and argon gases was employed to render a hydrophilic property of woven polyester fabrics and facilitate the absorption of a palladium catalyst in order to provide a catalytic surface for electroless nickel plating. The properties of plasma-induced electroless nickel-plated polyester fabrics were evaluated by various standard testing methods in terms of both physical and chemical performances.

Yuen, C. W. M.; Jiang, S. Q.; Kan, C. W.; Tung, W. S.

2007-04-01

103

Bioremediation of pesticide contaminated water using an organophosphate degrading enzyme immobilized on nonwoven polyester textiles.  

PubMed

Bioremediation using enzymes has become an attractive approach for removing hazardous chemicals such as organophosphate pesticides from the environment. Enzymes immobilized on solid carriers are particularly suited for such applications. In this study, the organophosphate degrading enzyme A (OpdA) was covalently immobilized on highly porous nonwoven polyester fabrics for organophosphate pesticide degradation. The fabrics were first activated with ethylenediamine to introduce free amine groups, and the enzyme was then attached using the bifunctional crosslinker glutaraldehyde. The immobilization only slightly increased the Km (for methyl parathion, MP), broadened the pH profile such that the enzyme had significant activity at acidic pH, and enhanced the stability of the enzyme. The OpdA-functionalized fabrics could be stored in a phosphate buffer or in the dry state at 4°C for at least 4 weeks without a large loss of activity. When used in batch mode, the functionalized textiles could degrade 20 ?M MP in un-buffered water at liquor to fabric ratios as high as 5000:1 within 2h, and could be used repeatedly. The fabrics could also be made into columns for continuous pesticide degradation. The columns were able to degrade 50 ?M MP at high flow rates, and could be used repeatedly over 2 months. These results demonstrate that OpdA immobilized on nonwoven polyester fabrics is useful in environmental remediation of organophosphate compounds. PMID:24267566

Gao, Yuan; Truong, Yen Bach; Cacioli, Paul; Butler, Phil; Kyratzis, Ilias Louis

2014-01-10

104

A novel acrylic\\/polyester system for powder coatings  

Microsoft Academic Search

Summaries  An acrylic\\/polyester system has been introduced for powder coatings as an altemative system to TGIC.\\u000a \\u000a In a typical polyester\\/blocked-isocyanate system or polyester\\/TGIC system, a higher terephtholic acid (TPA) content polyester\\u000a resin shows good mechanical properties, but the exterior durability is not good enough. On the other hand, a polyester based\\u000a on isophtholic acid (IPA) shows excellent exterior durability, but the

G. Iwamura; T. Agawa; K. Maruyama; H. Takeda

2000-01-01

105

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

106

Review of Polyester Polymer Concrete Properties  

Microsoft Academic Search

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

Victor Y. Garas; C. Vipulanandan

107

Nanoindentation of polycarbonate and polyester coatings  

Microsoft Academic Search

Nanoindentation can be considered to be an invaluable technique for getting modulus and hardness of thin coatings of magnetic storage and polymeric devices for predicting their wear. Characteristic relaxation time in crossliked polystyrene has been correlated to crosslinking. We invesigated nanoindentaion of coatings of polycarbonate, polyester and polyvinyl butryl on aluminum substrate. Young's modulus, dynamic storage modulus and tan delta

Suresh K. Ahuja Ahuja; Karl B. Yoder Yoder

1998-01-01

108

Preparation and evaluation of bicomponent and homogeneous polyester silk small diameter arterial prostheses.  

PubMed

The development of a small diameter (?5?mm) arterial prosthesis requires the appropriate selection of materials, structure and fabrication method so as to provide adequate mechanical properties, superior biocompatibility and precise control over the diameter. In this study, 100% polyester, 100% silk fibroin and a combination of both yarns were woven into seamless tubular prototype prostheses with different basic weaves. After degumming/scouring they met a target inner diameter of 3.9±0.3?mm which demonstrates that weaving is a precise way to manufacture small caliber arterial prostheses. In conclusion, the bicomponent polyester/silk woven samples had superior mechanical properties and improved cytocompatibility compared to commercial ePTFE devices. PMID:23292721

Yang, Xiaoyuan; Wang, Lu; Guan, Guoping; King, Martin W; Li, Yuling; Peng, Lei; Guan, Ying; Hu, Xingyou

2014-01-01

109

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

Code of Federal Regulations, 2012 CFR

...Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food...Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section and...

2012-04-01

110

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

Code of Federal Regulations, 2011 CFR

...Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food...Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section and...

2011-04-01

111

Silk / absorbable polyester hybrid medical devices and applications thereof  

US Patent & Trademark Office Database

Silk/absorbable polyester hybrid medical devices for tissue repair and regeneration are formed of degummed, naturally produced, multifilament silk yarn in combination with at least one absorbable polyester in the form of a surface coating, with or without an antimicrobial agent, for producing value-added braided silk sutures and multifilament yarn, as well as silk/absorbable polyester fiber composites, for producing tailored hybrid sutures, meshes, and scaffolds for tissue regeneration.

2013-11-12

112

Synthese, caracterisation et applications de polyesters derives d'oligothiophenes  

Microsoft Academic Search

Le travail presente ici a pour but de synthetiser des polyesters derives d'oligothiophenes utilisables dans des diodes electroluminescentes et des dispositifs optiques non-lineaires. Differents polyesters derives d'oligothiophenes (de une a six unites) ont ete synthetises par polycondensation en masse. Trois groupes espaceurs ont ete utilises: le 1, 10-decanediol, le 1,6-hexanediol et l'hexaethyleneglycol. La structure chimique des polyesters a ete etudiee

Anne Donat-Bouillud

1998-01-01

113

Bio-based liquid crystalline polyesters  

NASA Astrophysics Data System (ADS)

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

Wilsens, Carolus; Rastogi, Sanjay

2013-03-01

114

[IR studies on deuterated polyester polyurethaneurea elastomers].  

PubMed

Segmented polyester polyurethaneurea (PUU) based on 4,4'-disphenylmethane diisocyanate (MDI), ethylene diamine (ED) and polybutylene adipate (PBA) elastomers and their deuterated polymers were studied by means of IR spectroscopy. The results indicated that IR bands of hydrogen bonded N-H vibrations involved in PUU were greatly affected by deuteration. The bands which were sensitive to deuteration were those near 3,332, 3,190, 1,600, 1,539, 1,317, 1,257 and 1,230 cm-1, respectively. In addition, it was also found that PUU samples with different hard segment contents and polyester soft segment molecule weights were similarly affected by deuteration in degree. PMID:12947613

Guo, X; Wang, Z; Zhao, X; Zhang, G; Zhao, G

2001-04-01

115

Photochemistry of some liquid crystalline stilbene polyesters  

NASA Astrophysics Data System (ADS)

The photochemical behavior of thin films and solutions of main chain nematic liquid crystalline trans-stilbene dicarboxylate polyesters (SDA) is discussed. Observation of spectral differences between solutions and thin films indicates the presence of chromophore aggregation. Hypochromic effects attributed to aggregation of chromophores become more pronounced upon thermal annealing above 40 degree(s) C. Polymer solutions and thin films (above 40 degree(s) C) exhibit the ability to undergo a reversible photocycloaddition reaction.

Creed, David; Cozad, Richard A.; Hoyle, Charles E.; Morris, Jack C.; Jackson, W. J., Jr.

1993-01-01

116

Phase Behavior of Aromatic Polyester/Poly(ether imide) Blends  

NASA Astrophysics Data System (ADS)

The phase behavior of amorphous and semicrystalline blends of three aromatic polyesters (PET, PBT and PEN) with poly(ether imide) (PEI) have been investigated. The polyesters were miscible with PEI in the melt. A PEI- rich phase containing ca. 80 wtof polyesters. This observed composition deviated from the composition calculated by assuming a simple liquid-solid phase separation. Morphological observation by optical microscopy revealed simultaneous occurrence of spinodal decomposition and crystallization, where modulated structure was locked in by the crystallization of polyesters. A UCST phase diagram with the binodal line located below the equilibrium melting point was identified.

Chen, Hsin-Lung

1998-03-01

117

Development of Shade Standard and Shade Tolerances in Blue 1549 Wool/Polyester Cloth, Stock Dyed Conforming to Type 111 of Specification MIL-C-21115B.  

National Technical Information Service (NTIS)

The purpose of this project was to develop shade standards and eight tolerances of Air Force Blue 1549 in polyester/wool fabric, conforming to Type III of Specification MIL-C-21115B, by blending dyed primaries in top form to match the shade standard by th...

C. Anderson

1968-01-01

118

Mechanical behavior of polyester-based woven jute/glass hybrid composites  

NASA Astrophysics Data System (ADS)

In polymer composite fabrication system, hybridization of jute fibers with synthetic fibers is one of the techniques adopted to overcome some of the limitations (poor mechanical properties and moisture resistance) that have been identified for jute fiber reinforced composites. In the present study, the effect of hybridization on mechanical properties of jute and glass mat reinforced polyester composites has been evaluated experimentally. The composites were made of glass mat, jute mat and varying layers of jute and glass mat in the polyester matrix by applying hand lay-up technique at room temperature (250C). The values of mechanical properties obtained from tensile, flexural and interlaminar shear strength (ILSS) tests show significant improvement with the increase of glass fiber content in hybrid composites. But the positive contribution from glass mat in increasing of ILSS of composite is limited to some extent and the optimum ILSS is achieved when glass-jute incorporated in composite as 50-50 weight basis. SEM images were used to study the modes of fracture, fiber-matrix adhesion, and jute-glass layer adhesion. The fracture surfaces resulted from different tests clearly show that cracks propagate throughout the polyester matrix by tearing the jute mat and delaminating the glass mat.

Ahsan, Q.; Tanju, S.

2012-06-01

119

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

120

Experimental investigation of deposition and removal of particles during gas filtration with various fabric filters  

Microsoft Academic Search

The aim of this study was to investigate the deposition of particles in three types of synthetic fabric filter by scanning electron microscope (SEM) and to determine the experimental adhesive force of filter cakes in fabric filters. The fabrics used were acrylic, polypropylene and polyester. The particulate matter was phosphate rock. The particles were deposited in the filters during 10

E. H. Tanabe; P. M. Barros; K. B. Rodrigues; M. L. Aguiar

2011-01-01

121

Blends of Liquid Crystalline Polyesters and Polyethylene Terephthalate - Morphological Studies  

Microsoft Academic Search

Polyethylene terephthalate (PET) was blended with two different kinds of liquid crystalline (LC) polyesters with the level of LC polyester varying from 5 to 15 weight %. Homogeneous samples were prepared by melt blending the polymers in twin screw extruder. The crystallization and morphology of these blends was studied with the help of differential scanning calorimetry (DSC), small angle light

S. K. Sharma; A. Tendolkar; A. Misra

1988-01-01

122

Branched biodegradable polyesters for parenteral drug delivery systems.  

PubMed

Continuous, 'infusion-like' drug release profiles from biodegradable parenteral delivery systems are difficult to achieve for proteins and other hydrophilic macromolecular drugs with commonly used linear polyesters from lactic acid (PLA) and its random copolymers with glycolic acid (PLG). Drug release rates can be modified either by increasing the hydrophilicity of polyesters or by manipulating the polymer architecture to adjust polymer degradation rates and thus drug release. Therefore, we investigated different branching concepts for biodegradable polyesters of PLA and PLG. For one four- and eight-arm poly(ethylene oxide)s (PEO) were grafted with shorter polyester chains leading to star-branched structures. Secondly we obtained comb-like polyesters using both charged and uncharged dextrans or poly(vinyl alcohol)s (PVA) as hydrophilic backbones. The star-shaped and brush-like grafted polymers were intensively characterized by methods, such as NMR, IR, SEC-SLS, DSC and viscosity measurements. Tailor-made properties make these novel biodegradable polyesters promising candidates for parenteral protein delivery systems. While the star-branched polyesters have shown some interesting properties with respect to their degradation behavior, retaining the PEO blocks longer than ABA triblock copolymers, their release properties need further optimization. Brush-like branched polyesters on the other hand seem to possess both degradation and release properties meriting further investigations for parenteral protein delivery systems. PMID:10640655

Breitenbach, A; Li, Y X; Kissel, T

2000-02-14

123

The Effect of Test Conditions On the Relative Toxicity of the Pyrolysis Products From Some Upholstery Fabrics  

Microsoft Academic Search

Nine upholstery fabrics were evaluated for relative toxicity using seven different test conditions of the USF methodology. The materi als were 99% wool\\/1% spandex, 86% wool\\/14% nylon, 100% polyester, 100% cotton, 100% rayon, 100% polyolefin, and 100% nylon.

Carlos J. Hilado; Heather J. Cumming

1977-01-01

124

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

125

Synthesis of polyesters-perfluoropolyethers block copolymers  

Microsoft Academic Search

Summary  Multiblock-(A-B)n-copolymers containing polyester segments together with perfluoropolyether (PFPE) segments have been prepared by polymerizing\\u000a dimethyl terephthalate (DMT), or an equimolar mixture of DMT and dimethyl isophthalate (DMI), with ethylene glycol (EG) in\\u000a the presence of different telechelic perfluoropolyethers in various amounts (5–30 wt%), using Tl(OBu)4 as the catalyst. Fomblin ZDEAL (a-COOCH3 terminated PFPE), Fomblin ZDOL (a PFPE having-CH2OH terminal groups),

F. Pilati; M. Toselli; A. Vallieri; C. Tonelli

1992-01-01

126

Disposable polyester-toner electrophoresis microchips for DNA analysis.  

PubMed

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

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

2012-06-01

127

Acrylic\\/polyester hybrid powder coating system having excellent weather durability  

Microsoft Academic Search

There have been many attempts to improve weather durability in polyester powder coatings. However, no effective suggestion improves weather durability without sacrificing other properties, such as mechanical properties. A novel polyester powder coating system is described in this article, with especially excellent weather durability. This system was based on an acrylic\\/polyester hybrid curing system composed of polyester resin showing excellent

Katsuhiko Okadaa; Kouichi Yamaguchi; Hirofumi Takeda

1997-01-01

128

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

129

Initiating system for solid polyester granule manufacture  

US Patent & Trademark Office Database

The invention relates to the use of a diacyl peroxide in combination with an aromatic amine of formula (I) where R.sup.1 is C.sub.1 -C.sub.20 alkyl having at least one hydroxy substituent or --(CH'CHR'--O).sub.n H where n is 1 to 10 and each R' is independently selected from H and C.sub.1 -C.sub.3 alkyl; R.sup.2 is C.sub.1 -C.sub.20 alkyl optionally substituted with one or more hydroxy groups, or --(CHR'CHR'--O).sub.n H where n=1 to 10; and each R is independently selected from H and C.sub.1 -C.sub.3 alkyl; and Ar is an optionally substituted aryl group; as a redox initiating system in a process for the manufacture of polyester granules by suspension polymerisation. This invention also relates to a process for preparing solid polyester granules using such a redox initiating system.

2003-03-18

130

PES fabric plasma modification  

NASA Astrophysics Data System (ADS)

Polyester ranks the upper position in the world fiber production — nearly 54% of the total production of synthetic fibers. Troubles connected with minimizing of the textile hydrophobicity are usually being solved by the textile fibers’ surface chemical modification, but from ecological point of view modification of fabric with low temperature plasma is superior to classical chemical wet processes. Application of various plasmas for PES treatment has been already described. To compare the effectiveness of different plasma sources we performed a series of experiment both in RF and MW plasmas. For working gas nitrogen, oxygen and their mixtures were employed. Internal plasma control was provided by measurement of optical emission spectra. The hydrophilicity degree was determined by the drop test. Paper discusses optimal conditions of the PES fabric plasma treatment.

Vatu?a, T.; Špatenka, P.; Píchal, J.; Koller, J.; Aubrecht, L.; Wiener, J.

2004-03-01

131

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

132

Process of Resin Treating a Cotton Batting.  

National Technical Information Service (NTIS)

The fibrous batts are used in the furniture and automotive industries for upholstery, mattresses and automotive cushioning. The web of opened textile fibers of cotton are treated before final forming with a resin. The resin is made of dimethylol ethyl car...

N. B. Knoepfler H. K. Gardner H. L. E. Vix

1965-01-01

133

Hydrolysis of polyesters by serine proteases.  

PubMed

The substrate specificity of alpha-chymotrypsin and other serine proteases, trypsin, elastase, proteinase K and subtilisin, towards hydrolysis of various polyesters was examined using poly(L-lactide) (PLA), poly(beta-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(epsilon-caprolactone) (PCL). alpha-Chymotrypsin could degrade PLA and PEA with a lower activity on PBS/A. Proteinase K and subtilisin degraded almost all substrates other than PHB. Trypsin and elastase had similar substrate specificities to alpha-chymotrypsin. PMID:15928850

Lim, Hyun-A; Raku, Takao; Tokiwa, Yutaka

2005-04-01

134

[IR studies on segmented polyester polyurethaneurea elastomers].  

PubMed

The studies segmented polyester polyurethaneurea (PUU) elastomers based on 4,4'-diphenylmethane diisocyanate (MDI), ethylene diamine (ED) and polybutylene adipate(PBA) (M.W.1,975 and M.W.1,228) were studied by means of IR spectrascopy. The major IR bands of PUU were first assigned and the views were proposed for the bands at 1,600, 1,317, 1,520 and 1,230 cm-1 assigned by other authors. The reliable theoretical basis for the assignments of IR bands and the studies of hydrogen bonding in these elastomers has been proposed by use of deuteration and varying temperature. The results indicated that substantial hydrogen bonding mainly occurred in the aggregate region of hard segments, a small amount of hydrogen bonding can be formed at the interface between the soft and hard segments. It can be concluded from this work that the studied PUU materials were phase segregation. PMID:12947657

Guo, X; Wang, Z; Zhang, G; Zhao, G; Zhao, W

2001-06-01

135

The Kinetics of Hydrolytic Aging of Polyester Urethane Elastomers.  

National Technical Information Service (NTIS)

The hydrolytic degradation of polyester urethane elastomers is due to the acid catalyzed hydrolysis of the ester group. Acid content (A) and the reciprocal of the number average molecular weight increase by equivalent amounts indicating that each molecula...

D. W. Brown R. E. Lowry L. E. Smith

1979-01-01

136

Kinetic Study of Hydrolysis of Polyester Elastomer in Magnetic Tape.  

National Technical Information Service (NTIS)

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.

K. Yamamoto H. Watanabe

1994-01-01

137

An Assessment of Recently Developed Thermoplastic Polyurethane and Polyester Elastomers.  

National Technical Information Service (NTIS)

The processing characteristics and aging properties of thermoplastic, injection moulded polyurethane and polyester copolymer elastomers have been assessed. The aging properties of the polyurethanes showed little improvement compared with cast and millable...

J. Wright

1973-01-01

138

Fiberglass Polyester Resin (FPR) Coating System for Fleet Mooring Buoys.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. A procedure to protect steel mooring buoys uses a fiberglass polyester resin (FPR) coating instead of the one coating system generally used. ...FOR ADDITIONAL INFORM...

1982-01-01

139

Vanadium Trineodecanoate Promoter for Fiberglass-Polyester Soil Surfacings.  

National Technical Information Service (NTIS)

A Marine Corps chemical formulation developed for the construction of fiberglass-reinforced plastic surfaces for soils consists of a polyester resin, cumene hydroperoxide catalyst and a promoter solution containing a vanadium salt and N,N-dimethyl-p-tolui...

A. L. Woodman R. A. Henry A. Adicoff D. A. Fine

1980-01-01

140

Amino alcohol-based degradable poly(ester amide) elastomers  

Microsoft Academic Search

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

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

2008-01-01

141

Optical Storage in Side-Chain Liquid Crystalline Polyesters  

Microsoft Academic Search

Long-term, high resolution holographic storage has been achieved in side-chain liquid crystalline polyesters with high diffraction efficiency. The information can be completely erased by heating the film to about 80°C. The modular architecture of the polyesters permits a varition in the length of the main- and side-chains and the substituents of the azo chromophore. Each of these has a profound

P. S. RAMANUJAM; Fulvio Andruzzi; Søren Hvilsted

1994-01-01

142

Degradation kinetics of glass-reinforced polyesters in chemical environments  

Microsoft Academic Search

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

S. P. Sonawala; R. J. Spontak

1996-01-01

143

Correlation between Morphology and Electrical Response in PEN Polyester Film  

Microsoft Academic Search

Thermoplastic polyesters have been widely used in electrical and electronic equipment and a large number of articles on these materials have been published in the past several decades. Poly (ethyethylene-2,6-naphthalene dicarboxylate) (PEN) is a new aromatic polyester that presents high-performance physical and chemical properties. It is well known that the study of the physical\\/chemical structure and its effect on the

S. Berdous; N. Saidi-Amroun; M. Saidi; M. Bendaoud

2010-01-01

144

Commercial Flame Retardancy of Unsaturated Polyester and Vinyl Resins: Review  

Microsoft Academic Search

Chlorendic acid-based and tetrabromophthalate polyesters are major flame-retardant polyester resins, often used with antimony trioxide. For translucency, colloidal antimony pentoxide is preferred. Brominated diols are occasionally used. In the vinyl ester group, the adducts of acrylic or methacrylic acid with the diglycidyl ether of tetrabromobisphenol A are prodominant, and the styrene-cured resins often have advantageous physical properties and hydrolytic stability.

Edward D. Weil; Sergei V. Levchik

2004-01-01

145

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

146

Flexible polyester cellulose paper supercapacitor with a gel electrolyte.  

PubMed

A low-cost polyester cellulose paper has been used as a substrate for a flexible supercapacitor device that contains aqueous carbon nanotube ink as the electrodes and a polyvinyl alcohol (PVA)-based gel as the electrolyte. Gel electrolytes have attracted much interest due to their solvent-holding capacity and good film-forming capability. The electrodes are characterized for their conductivity and morphology. Because of its high conductivity, the conductive paper is studied in supercapacitor applications as active electrodes and as separators after coating with polyvinylidene fluoride. Carbon nanotubes deposited on porous paper are more accessible to ions in the electrolyte than those on flat substrates, which results in higher power density. A simple fabrication process is achieved and paper supercapacitors are tested for their performance in both aqueous and PVA gel electrolytes by using galvanostatic and cyclic voltammetry methods. A high specific capacitance of 270 F?g(-1) and an energy density value of 37 W?h?kg(-1) are achieved for devices with PVA gel electrolytes. Furthermore, this device can maintain excellent specific capacitance even under high currents. This is also confirmed by another counter experiment with aqueous sulfuric acid as the electrolyte. The cycle life, one of the most critical parameters in supercapacitor operations, is found to be excellent (6000 cycles) and less than 0.5?% capacitance loss is observed. Moreover, the supercapacitor device is flexible and even after twisting does not show any cracks or evidence of breakage, and shows almost the same specific capacitance of 267 F?g(-1) and energy density of 37 W?h?kg(-1) . This work suggests that a paper substrate can be a highly scalable and low-cost solution for high-performance supercapacitors. PMID:24155269

Karthika, Prasannan; Rajalakshmi, Natarajan; Dhathathreyan, Kaveripatnam S

2013-11-11

147

Nanomolding based fabrication of synthetic gecko foot-hairs  

Microsoft Academic Search

This paper proposes two different nanomolding methods to fabricate synthetic gecko foot-hair nanostructures. The first method uses an atomic force microscope (AFM) probe indented flat wax surface and the second one uses a nano-pore membrane as a template. These templates are molded with silicone rubber, polyimide and polyester type polymers under vacuum and the template is peeled off or etched

Metin Sitti; Ronald S. Fearing

2002-01-01

148

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...

149

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

Microsoft Academic Search

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

Sennur Alay; Cemil Alkan; Fethiye Göde

2011-01-01

150

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

Microsoft Academic Search

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

Sennur Alay; Cemil Alkan; Fethiye Göde

2012-01-01

151

Wettability measurements on plasma treated synthetic fabrics by capillary rise method  

Microsoft Academic Search

The capillary rise method was applied to evaluate the improvement in water uptake of polyester and acrylic fabrics obtained by plasma treatment. Power, exposure time and gas type (nitrogen, air and oxygen) were considered as plasma variables. After plasma treatment, fabric samples were tested through capillary rise of water. The processing of a set of height absorption values vs. time,

F Ferrero

2003-01-01

152

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

Microsoft Academic Search

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

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

2011-01-01

153

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...

154

Shock Wave Profiles in Glass Reinforced Polyester  

NASA Astrophysics Data System (ADS)

The promise of lightweight armor which is also structurally robust is of particular importance to the Army for future combat vehicles. Fiber reinforced organic matrix composites such as Glass Reinforced Polyester (GRP) are being considered for this purpose due to their lower density and promising dynamic response. The work discussed here extends the prior work of Boteler who studied the delamination strength of GRP and Dandekar and Beaulieu who investigated the compressive and tensile strengths of GRP. In a series of shock wave experiments, the wave profile was examined as a function of propagation distance in GRP. Uniaxial strain was achieved by plate impact in the ARL 102 mm bore single-stage light gas gun. Embedded polyvinylidene flouride (PVDF) stress-rate gauges provided a stress history at three unique locations in the GRP and particle velocity history was recorded with VISAR. The use of Lagrange gauges embedded in such a manner provides a means of calculating the constitutive relationships between specific volume, stress, and particle velocity uniquely with no prior assumptions of the form of constitutive relation. The Lagrangian analysis will be discussed and compared to Lagrangian hydrocode (EPIC) results employing a model to describe the viscoelastic response of the composite material in one-dimension.

Boteler, J. Michael; Rajendran, A. M.; Grove, David

1999-06-01

155

Design and fabrication of low cost filament winding machine  

Microsoft Academic Search

In general, the composite pipes are fabricated using glass fiber and polyester resin matrix by hand lay-up and also by 2-axis filament winding machine. In this work, a filament winding machine was designed and developed for the fabrication of pipes and round shape specimens. A lathe-type machine and a wet winding method were used in the design of the machine.

F. H. Abdalla; S. A. Mutasher; Y. A. Khalid; S. M. Sapuan; A. M. S. Hamouda; B. B. Sahari; M. M. Hamdan

2007-01-01

156

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

Federal Register 2010, 2011, 2012, 2013

...See Certain Polyester Staple Fiber From Taiwan: Final Results...also Certain Polyester Staple Fiber From Taiwan: Preliminary Results...Certain Corrosion-Resistant Carbon Steel Flat Products from the...Value: Certain Polyester Staple Fiber From the Republic of Korea...

2011-04-21

157

77 FR 32503 - Certain Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...Certain Polyester Staple Fiber From Taiwan: Final Results...Administrative Review: Carbon and Certain Alloy Steel...Certain Polyester Staple Fiber from Taiwan: Far Eastern...See Certain Welded Carbon Steel Pipe and Tube From...Certain Polyester Staple Fiber From the Republic...

2012-06-01

158

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

Microsoft Academic Search

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

Gul Hameed Awan; Liaqat Ali

2009-01-01

159

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

160

Extraction of lipid membrane incorporated vitamin E by sucrose polyesters.  

PubMed

2H and 31P solid state NMR have been used to probe, at the molecular level, the interaction between structurally different sucrose polyesters and a phospholipid membrane into which alpha-tocopherol and specifically deuterated alpha-[5,7-(2)H(6)] tocopherol has been incorporated. Our results show that at high concentration (>or=10 mol%) sucrose octapalmitate (SOP) and sucrose hexapalmitate (SHxP) deplete bilayer-associated alpha-tocopherol in dipalmitoyl phosphatidalcholine (DPPC) multilamellar dispersions and preferentially sequester the alpha-tocopherol into a fluid sucrose polyesters (SPE) phase located proximal to the membrane surface. It is demonstrated that the ability of SPEs to function as a 'lipophilic sink' depends strongly on sucrose polyester concentration and degree of esterification. PMID:11518572

McManus, G G; Buchanan, G W; Jarrell, H C

2001-07-01

161

Polysilicon TFT fabrication on plastic substrates  

SciTech Connect

Processing techniques utilizing low temperature depositions and pulsed lasers allow the fabrication of polysilicon thin film transistors (TFT`s) on plastic substrates. By limiting the silicon, SiO2, and aluminum deposition temperatures to 100(degrees)C, and by using pulsed laser crystallization and doping of the silicon, we have demonstrated functioning polysilicon TFT`s fabricated on polyester substrates with channel mobilities of up to 7.5 cm2/V-sec and Ion/Ioff current ratios of up to 1x10(to the 6th power).

Carey, P.G.; Smith, P.M.; Wickboldt, P.W.; Thompson, M.O.; Sigmon, T.W.

1997-08-06

162

Polyester wax embedding and sectioning technique for immunohistochemistry.  

PubMed

We have developed a method useful for immunohistochemical studies by combining tissue fixation with buffered neutral formalin and polyester wax embedding. Buffered neutral formalin fixation preserves cell and tissue fine structure, and also the antigenicity of unstable enzymes. Polyester wax embedding makes possible thin serial sections of various tissues and preserves antigenicities for at least 6 months. We have demonstrated using this technique the localization of alpha-amylase in mouse salivary gland, parietal-cell specific antigen in mouse glandular stomach, and DNA polymerase alpha and beta in chick tissue. PMID:6207637

Kusakabe, M; Sakakura, T; Nishizuka, Y; Sano, M; Matsukage, A

1984-05-01

163

Tandem synthesis of alternating polyesters from renewable resources  

PubMed Central

The vast majority of commodity materials are obtained from petrochemical feedstocks. These resources will plausibly be depleted within the next 100 years, and the peak in global oil production is estimated to occur within the next few decades. In this regard, biomass represents an abundant carbon-neutral renewable resource for the production of polymers. Here we report a new strategy, based on tandem catalysis, to obtain renewable materials. Commercially available complexes are found to be efficient catalysts for alternating polyesters from the cyclization of dicarboxylic acids followed by alternating copolymerization of the resulting anhydrides with epoxides. This operationally simple method is an attractive strategy for the production of new biodegradable polyesters.

Robert, Carine; de Montigny, Frederic; Thomas, Christophe M.

2011-01-01

164

Fabrication and dynamic mechanical behavior of nanocomposites  

NASA Astrophysics Data System (ADS)

Polyester/TiO2 nanocomposites have been fabricated using an in-situ polymerization technique coupled with ultrasonics, and an investigation has been conducted to characterize their mechanical and fracture behavior under quasi-static and dynamic loading conditions. The presence of the particles had the greatest effect on fracture toughness; negligible particle influence was observed in the remaining mechanical properties obtained using quasi-static loading. Scanning electron microscopy analysis of fracture surfaces was carried out to identify toughening mechanisms. Dynamic fracture toughness testing was carried out, and an increase in dynamic fracture toughness relative to quasi-static fracture toughness was observed. High strain rate testing conducted using a split-Hopkinson pressure bar apparatus revealed a moderate stiffening effect with increasing particle volume fraction. Dynamic photoelasticity coupled with high-speed photography was used to obtain the dynamic fracture constitutive behavior of polyester and nanocomposites. Birefringent coatings were used to conduct the photoelastic study due to the opaqueness of the nanocomposites. Two different specimen geometries were employed to obtain a broad range of crack velocities. Crack run-arrest, propagation, and branching events in polyester and nanocomposites were investigated and compared. Crack arrest toughness in nanocomposites was found to be 60% greater than that in polyester. Crack propagation velocities in nanocomposites were found to be 50% greater than those in polyester. Incipient branching values were 2.4 and 2.6 times the corresponding values of KIC in polyester and nanocomposites, respectively. A one-point strain measurement technique using a modified Hopkinson pressure bar apparatus was employed in a parametric study to evaluate the limiting conditions of validity of employment of quasi-static relations in the determination of dynamic fracture initiation toughness in brittle and moderately brittle polymers. The technique was combined with photoelastic analysis and high-speed photography to validate results obtained in polyester and PMMA (polymethylmethacrylate) three-point bend specimens. Specimen size, crack length, incident pulse length and amplitude, and loading rate were variables used in the parametric study. A hypothesis was proposed and tested in an effort to explain how inertia effects interfere with the measurement of dynamic fracture initiation toughness using the one-point strain measurement technique.

Evora, Victor Manuel Fortes

165

Test method for evaluating fabric flammability and predicted skin burn injury in microgravity  

Microsoft Academic Search

To address fire safety concerns associated with the use of flammable fabrics during space travel, an apparatus was designed\\u000a to be flown on low-gravity parabolic aircraft flights in order to assess the flammability of cotton and 50% cotton\\/50% polyester\\u000a fabrics, and the resulting skin burn injury that would occur if these fabrics were to ignite. The apparatus, modelled after\\u000a a

Jane M. Cavanagh; David A. Torvi; Kamiel S. Gabriel; Gary. A. Ruff

2006-01-01

166

Optimization of the Dyeing Process and Prediction of Quality Characteristics on Elastic Fiber Blending Fabrics  

Microsoft Academic Search

This study aims to find the optimal conditions for dyeing polyester (PET) and Lycra®-blended fabric and predict the quality characteristics, where PET and Lycra®-blended fabric were taken as raw material with dispersed dyes using a one-bath two-section dyeing method, characterizing the color strength of gray fabric. Adopting the Taguchi method for parameter design, machine working temperature, dyeing time, dye concentration,

C.-F. J. Kuo; C.-D. Chang; T.-L. Su; C.-T. Fu

2008-01-01

167

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

168

THE REUSE OF THE ARMED POLYESTER FIBER GLASS WASTES  

Microsoft Academic Search

The production evolution of the unsaturated and armed polyesters fiber glass (PFG) is determinate by the advantages offered by this material: weight reduction of the pieces, resistance to the chemical agents and bad weather as against the metals objects, energy consume reduction needed for the finite pieces obtaining by simplification and removal of a lot of production phases, increased work

P. Negre; M. Ciopec; L. Lup

169

Electrokinetic approach of adhesion between polyester fibres and latex matrices  

Microsoft Academic Search

The adhesive interaction between salt-treated polyester fibres and elastomeric matrices has been studied. Two types of approaches have been used to predict the impact of the salt treatment on the interaction between both jointing partners. First of all ?-potential measurements have been used to characterize the interactions between fibre and matrix. Changes in the surface composition of salt-treated fibres were

C Campagne; E Devaux; A Perwuelz; C Cazé

2002-01-01

170

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

171

Severe postural hypotension following home canoe construction from polyester resins.  

PubMed

On two occasions a 36-year-old man developed severe postural hypotension and neurological signs after working with a polyester resin canoe building kit in an unventilated shed. It is likely that his recurrent illness was caused by styrene intoxication. Postural hypotension secondary to styrene exposure has not previously been reported. PMID:6463006

MacFarlane, I A; Wilkinson, R; Harrington, J M

1984-07-01

172

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’.

Kobayashi, Shiro

2010-01-01

173

Relaxation processes in hyperbranched polyesters: influence of terminal groups  

Microsoft Academic Search

Three hyperbranched polyesters with the same backbone structure but with different terminal groups: hydroxyl, benzoate or acetate groups, were studied by dielectric spectroscopy, differential scanning calorimetry and dynamic mechanical analysis. The benzoate- and acetate-terminated polymers exhibited only one subglass process (?), originating from reorientation of the ester groups, distinct from the glass transition (?). The hydroxyl-terminated sample exhibited a low-temperature

F. Liu; R. H. Boyd

1997-01-01

174

Modification of polyester resins with active mineral fillers  

Microsoft Academic Search

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

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

1996-01-01

175

Resource Conservation Through Beverage-Container Recycling (Polyester (PET) Bottles).  

National Technical Information Service (NTIS)

Since the introduction of plastic soft-drink bottles in 1977, the 2 liter container has captured almost the entire US market. The number of PET (polyethylene terephthalate, a polyester) bottles used in 1981 was 2.4 billion, and could grow to 14 billion by...

L. L. Gaines A. M. Wolsky

1982-01-01

176

Progressive crushing of stitched glass\\/polyester composite cylindrical shells  

Microsoft Academic Search

This paper examines the effect of mode I interlaminar fracture toughness (GIc) on the specific energy absorption of stitched glass\\/polyester composite cylindrical shells under axial compression. The laminated composite cylindrical shells used as energy absorbers, absorb large amount of impact energy during collision. Since mode I delamination in the thin wall of axially collapsed shell is one of the major

S. Solaimurugan; R. Velmurugan

2007-01-01

177

Biological properties of jatrophane polyesters, new microtubule-interacting agents  

Microsoft Academic Search

Purpose. The biological activities of macrocyclic jatrophane polyesters 1-3 from the Sardinian endemism Euphorbia semiperfoliata Viv. have not been evaluated in depth. We investigated the microtubule-interacting and antiproliferative activities of these drugs and the molecular mechanisms underlying their effects. Methods. We tested jatrophanes for their interaction with purified bovine brain tubulin by an in vitro polymerization assay and by electron

Antonella Miglietta; Ludovica Gabriel; Giovanni Appendino; Claudia Bocca

2003-01-01

178

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

179

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

180

Syntheses and Optical Properties of Polyesters with Disperse Red 19 by the Polycondensation Reaction  

Microsoft Academic Search

We synthesized the polyesters containing azobenzene units in the side chain for data storage materials. The structurally similar polyesters, DR-Est-1, DR-Est-2 and DR-Est-3 were synthesized to compare the optical properties of polyesters with different structure from dihalide in the main chain. The diffraction efficiencies of films were measured as a function of the reaction time. Typically, the diffraction efficiency of

Mi-Ra Kim; Phan-Seok Kim; Hooi-Sung Kim; Gee-Young Sung; Ki-Hyun Kim; Chang-Sik Ha; Chong-Hoon Kwak; Jin-Kook Lee

2002-01-01

181

Effect of unsaturated polyester resin on the mechanical and ultrasonic properties of SBR and NBR  

Microsoft Academic Search

An unsaturated polyester resin is prepared by the ester interchange between p-carbethoxy phthalanilic acid and maleic anhydride with ethylene glycol in the ratio of (1:1:2.1mol). The structure of this polyester was established by studying its IR and NMR spectra and the acid number was determined. The effect of 5phr polyester on the mechanical and physical properties of two types of

M. H. Youssef; S. H. Mansour; S. Y. Tawfik

2000-01-01

182

Organic–inorganic hybrid coatings for coil coating application based on polyesters and tetraethoxysilane  

Microsoft Academic Search

Organic–inorganic hybrid coating systems based on polyesters and tetraethoxysilane (TEOS) are synthesized and evaluated to develop protective coatings with improved performance for prefinish construction steel and aluminium. The coatings have to combine flexibility, necessary for enduring deformation of the metal substrate after coating, and hardness for improved mechanical properties. Two systems have been studied: a polyester–TEOS system and a polyester–epoxide–TEOS

S Frings; H. A Meinema; C. F van Nostrum; R van der Linde

1998-01-01

183

Synthesis of silver nanoparticles in melts of amphiphilic polyesters  

NASA Astrophysics Data System (ADS)

The current work presents a one-step procedure for the synthesis of amphiphilic silver nanoparticles suitable for production of silver-filled polymeric materials. This solvent free synthesis via reduction of Tollens’ reagent as silver precursor in melts of amphiphilic polyesters consisting of hydrophilic poly(ethylene glycol) blocks and hydrophobic alkyl chains allows the production of silver nanoparticles without any by-product formation. This makes them especially interesting for the production of medical devices with antimicrobial properties. In this article the influences of the chain length of the hydrophobic block in the amphiphilic polyesters and the process temperature on the particle size distribution (PSD) and the stability of the particles against agglomeration are discussed. According to the results of spectroscopic and viscosimetric investigations the silver precursor is reduced to elemental silver nanoparticles by a single electron transfer process from the poly(ethylene glycol) chain to the silver ion.

Vasylyev, S.; Damm, C.; Segets, D.; Hanisch, M.; Taccardi, N.; Wasserscheid, P.; Peukert, W.

2013-03-01

184

Amino alcohol-based degradable poly(ester amide) elastomers.  

PubMed

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 1MPa 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

2008-05-01

185

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...

186

Properties of melt processed chitosan and aliphatic polyester blends  

Microsoft Academic Search

Chitosan was melt blended with poly-?-caprolactone (PCL), poly(butylene succinate) (PBS), poly(lactic acid) (PLA), poly(butylene terephthalate adipate) (PBTA), and poly(butylene succinate adipate) (PBSA). For the chitosan\\/PBS blend, the amount of chitosan was varied from 25% to 70% by weight. The remaining polyesters had 50% of chitosan by weight. Addition of chitosan to PBS or PBSA tends to depress the melting temperature

V. M. Correlo; L. F. Boesel; M. Bhattacharya; J. F. Mano; N. M. Neves; R. L. Reis

2005-01-01

187

Lipase-catalyzed synthesis of aliphatic polyesters and properties characterization  

Microsoft Academic Search

A novel lipase-catalyzed synthesis of aliphatic polyesters has been achieved successfully by using Candida sp.99-125 with diethyl sebacate and 1,4-butanediol as starting substrates in absence of organic solvents. The lipase from Candida sp.99-125 was employed for the first time to catalyze synthesis of poly(butylene sebacate) and showed high catalytic activity for bulkpolymerization under mild reaction conditions. The eco-friendly processes, without

Wenhui Liu; Biqiang Chen; Fang Wang; Tianwei Tan; Li Deng

2011-01-01

188

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

189

Toughening modification of unsaturated polyester resin using HDI trimer  

Microsoft Academic Search

HDI trimer was firstly used to improve the mechanical properties of hydroxyl- terminated unsaturated polyester (UP). Mechanical\\u000a properties measurements performed on the cured materials demonstrate a distinct improvement in intensity and toughness in\\u000a the presence of HDI trimer and shows the change trends of increase and then decrease. The morphological analysis of the fracture\\u000a surfaces shows that the micro-phase separated

Huajun Duan; Lianmeng Zhang; Jun Wang; Xiaoli Yang; Xiang Wang

2009-01-01

190

Brush-like branched biodegradable polyesters, part III  

Microsoft Academic Search

Brush-like branched polyesters, obtained by grafting poly(lactic-co-glycolic acid), PLGA, onto water-soluble poly(vinyl alcohol) (PVAL) backbones, were investigated regarding their utility for the microencapsulation of proteins. Poly(vinyl alcohol)-graft-poly(lactic-co-glycolic acid), PVAL-g-PLGA, offers additional degrees of freedom to manipulate properties such as e.g. molecular weight, glass transition temperature and hydrophilicity. PLGA chain length was varied at a constant molecular weight (Mw) of the

Karin Frauke Pistel; Armin Breitenbach; Regina Zange-Volland; Thomas Kissel

2001-01-01

191

Nano-biocomposites: Biodegradable polyester\\/nanoclay systems  

Microsoft Academic Search

In the recent years, bio-based products have raised great interest since sustainable development policies tend to expand with the decreasing reserve of fossil fuel and the growing concern for the environment. Consequently, biopolymers, i.e., biodegradable polymers, have been the topic of many researches. They can be mainly classified as agro-polymers (starch, protein, etc.) and biodegradable polyesters (polyhydroxyalkanoates, poly(lactic acid), etc.).

Perrine Bordes; Eric Pollet; Luc Avérous

2009-01-01

192

Radiation-thickening of iso-polyester resin  

NASA Astrophysics Data System (ADS)

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

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

2007-06-01

193

Effects of oxygen in gamma irradiated aromatic polyesters in film  

Microsoft Academic Search

The effect of gamma irradiation in air is investigated on four thermoplastic polyesters (PET, PBT, PEN, PCT-co-ET) in films containing aromatic rings, in order to evaluate the influence of aromatic density and the role of oxygen on radiation resistance. Physical–chemical–nuclear analyses were used to this purpose. EPR measurements were carried out to detect radical stability against oxygen permeation. Viscometric investigations

Ugo Ravasio; Giovanni Consolati; Antonio Faucitano; Mario Mariani; Fiorenza Quasso

2007-01-01

194

Tribological investigation of thin polyester substrates for displays  

Microsoft Academic Search

Thin polyester films are currently used as substrates in thin flexible displays, touch-screens and flat panel displays. The advantages of using such films in various display technologies include excellent optical transparency, mechanical flexibility and they are light weight and low cost.However, little research has been reported to date on the tribological properties of such top-sheet display components. Nano-scale wear and

K. A. Sierros; S. N. Kukureka

2007-01-01

195

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

196

Nonisothermal melt-crystallization kinetics for three linear aromatic polyesters  

Microsoft Academic Search

The kinetics of nonisothermal crystallization of three different types of linear aromatic polyester, namely poly(ethylene terephthalate) (PET), poly(trimethylene terephthalate) (PTT), and poly(butylene terephthalate) (PBT), which are different in their number of methylene groups (i.e. 2, 3, and 4 for PET, PTT, and PBT, respectively), was investigated using differential scanning calorimetry (DSC). Analysis of the data was carried out based on

Pitt Supaphol; Nujalee Dangseeyun; Phornphon Srimoaon; Manit Nithitanakul

2003-01-01

197

Thermally-responsive poly(ester urethane)s  

NASA Astrophysics Data System (ADS)

Thermally-responsive materials are quite useful in the biomedical field, but their full potential has yet to be realized. For example, polyurethanes are capable of exhibiting shape-memory properties, or the ability to change shape upon the application of a stimulus, but only a few practical thermally responsive polyurethanes have been reported due to the lack of novel starting materials and optimized systems. This work describes the synthesis of several degradable polymers and the characterization of their thermally responsive behavior. First, several amorphous polyester prepolymers are synthesized and incorporated in thermoplastic poly(ester urethane)s, which are highly elastic but display impractical thermal properties. Their potential as degradable implants is investigated, as well as their bulk and surface properties. These systems are then optimized and tailored for more practical purposes, resulting in the synthesis of thermoset elastomers based on poly(1,4-cyclohexanedimethanol 1,4-cyclohexanedicarboxylate) (PCCD) prepolymers that display a broad range of useful mechanical properties, thermal properties, and shape-memory properties. A novel method for controlling a microscopic and nanoscopic topographical shape-memory phenomenon is presented. Finally, the synthesis of amine-functionalized polyesters is presented. All materials are characterized by 1H and 13C NMR, GPC, DSC, TGA, and Instron.

Pierce, Benjamin Franklin

198

ADBD plasma surface treatment of PES fabric sheets  

NASA Astrophysics Data System (ADS)

Plasma treatment of textile fabrics is investigated as an alternative to the environmentally hazardous wet chemical fabric treatment and pretreatment processes. Plasma treatment usually results in modification of the uppermost atomic layers of a material surface and leaves the bulk characteristics unaffected. It may result in desirable surface modifications, e.g. surface etching, surface activation, cross-linking, chain scission and oxidation. Presented paper contains results of the applicability study of the atmospheric pressure dielectric discharge (ADBD), i.e. dielectric barrier discharge sustaining in air at atmospheric pressure and ambient temperature for synchronous treatment of several sheets of fabric. For tests sheets of polyester fabric were used. Effectivity of the modification process was determined with hydrophilicity measurements evaluated by means of the drop test. Hydrophilicity of individual sheets of fabric has distinctly increased after plasma treatment. Plasma induced surface changes of textiles were also proven by identification of new functional groups at the modified polyester fabric surface. Existence of new functional groups was detected by ESCA scans. For verification of surface changes we also applied high-resolution microphotography. It has shown distinct variation of the textile surface after plasma treatment. Important aspect for practical application of the plasma treatment is the modification effect time-stability, i.e. time stability of acquired surface changes of the fabric. The recovery of hydrophobicity was fastest in first days after treatment, later gradually diminished until reached almost original untreated state.

Píchal, J.; Klenko, Y.

2009-08-01

199

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

200

75 FR 33783 - Certain Polyester Staple Fiber from the Republic of Korea: Preliminary Results of the 2008 - 2009...  

Federal Register 2010, 2011, 2012, 2013

...A-580-839] Certain Polyester Staple Fiber from the Republic of Korea: Preliminary...duty order on certain polyester staple fiber from the Republic of Korea. The period...covers imports of certain polyester staple fiber from one manufacturer/exporter....

2010-06-15

201

Structure–property relationship of different types of polyester industrial yarns  

Microsoft Academic Search

Four major types of polyester industrial yarns (1000 Denier) which are used commercially were studied for their key structural parameters. An attempt has been made to establish a relationship between morphology and properties of these yarns. High tenacity (HT) polyester yarn has the highest birefringence, amorphous orientation, and long period but is relatively less crystalline. High shrinkage characteristic of HT

Barun Kumar Samui; Manikanda Priya Prakasan; C. Ramesh; Debabrata Chakrabarty; R. Mukhopadhyay

2012-01-01

202

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

203

Photoinduced anisotropy measurements in liquid-crystalline azobenzene side-chain polyesters  

NASA Astrophysics Data System (ADS)

Reversible photoinduced anisotropy in a series of liquid-crystalline azobenzene side-chain polyesters is investigated as a function of intensity of the write beam and the sample temperature. Measurements reveal that the erasing takes place at a temperature much higher than the glass transition temperature. Induced anisotropy can be erased by heating the polyesters to approximately 80 C.

Holme, N. C. R.; Ramanujam, P. S.; Hvilsted, S.

1996-08-01

204

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

205

Tribo-performance of polyester hybrid composites: Damage assessment and parameter optimization using Taguchi design  

Microsoft Academic Search

This paper investigates the solid particle erosion wear performance of a multi component hybrid composite consisting of polyester, glass fibers and alumina particles. A mathematical model for damage assessment in erosion is developed and validated by a well designed set of experiments. For this, the design of experiments approach using Taguchi’s orthogonal arrays is used. The study reveals that glass–polyester

Amar Patnaik; Alok Satapathy; S. S. Mahapatra; R. R. Dash

2009-01-01

206

Lifetime and young's modulus changes of glass\\/phenolic and glass\\/polyester composites under fatigue  

Microsoft Academic Search

Fatigue of composites causes a loss of stiffness and development of damage before ultimate failure. These effects were compared for phenolic and polyester resins reinforced by five layers of woven roving\\/chopped strand combination glass mat. Such polyester laminates are widely used, e.g. in marine applications such as high speed craft. The phenolic laminates are promising candidates for applications where fire

Andreas T. Echtermeyer; Bjørn Engh; Leif Buene

1995-01-01

207

Influence of preparing of GFR recyclates on the properties of polyester matrix compsites  

Microsoft Academic Search

Purpose: The purpose of this project was to estimate the possibility of using polyester-glass fiber recyclate as a reinforced component of polymer matrix in composites. This kind of mechanical recycling can be use as one of the way of polymer composites utilization. Recyclates prepared from GFP - polyester resin reinforced glass filaments. Design\\/methodology\\/approach: Recyclate obtained after grinding was a mixture

J. Myalski; J. ?leziona

208

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...

209

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

210

The miscibility of poly(butylene terephthalate) (PBT) with phosphorus polyester flame retardants  

Microsoft Academic Search

Phosphorus polyesters provide sustainable flame retardancy to conventional polyesters like PET (poly(ethylene terephthalate)) and PBT (poly(butylene terephthalate)). Their use as a flame retardant additive results in the formation of a classical polymer blend. The morphology of such blends should determine the resulting fire behavior and has therefore to be examined in detail. This study investigates the state of miscibility in

Doris Pospiech; Liane Häußler; Andreas Korwitz; Oliver Fischer; Sandra Starke; Dieter Jehnichen; Thomas Köppl; Volker Altstädt

2012-01-01

211

Radiation Grafting of Acrylonitrile onto Polyester Fiber as the Reinforcing Filler for Poly (Vinyl Chloride).  

National Technical Information Service (NTIS)

Studies have been carried out on radiation-induced grafting of acrylonitrile onto polyester fiber and on the properties of the grafted fiber in an attempt to increase the strength of polyester fiber reinforced soft poly (vinyl chloride) (PVC) sheet by imp...

K. Kaji I. Ando

1985-01-01

212

The mechanism of pesticide transmission through apparel fabrics: a comparison of drop and spray exposure methodologies.  

PubMed

The effect of exposure methods on pesticide solution transmission and mechanism was examined for three fabrics. Drop and spray methods of exposure were used. The drop method of exposure resulted in significantly higher amounts of pesticide transmission than did the spray method. Using the drop method, a lower proportion of the particles remained in the top of the test fabric indicating much had transmitted into or through the fabric. The large droplet mass and increased volume per unit area produced during drop exposure resulted in a combination of increased force and saturation, enhancing the movement of the particle through the fabric. Fabric characteristics of construction and fiber content also influenced the transmission mechanism and quantity. The twill fabric was a better barrier to transmission than the plain fabrics. The cotton fabrics prevented transmission better than the cotton/polyester fabric. PMID:1859212

Leonas, K K

1991-04-01

213

Biodegradation of polyester polyurethane during commercial composting and analysis of associated fungal communities.  

PubMed

In this study the biodegradation of polyurethane (PU) during the maturation stage of a commercial composting process was investigated. PU coupons were buried in the centre and at the surface of a 10m high compost pile. Fungal communities colonising polyester PU coupons were compared with the native compost communities using culture based and molecular techniques. Putative polyester PU degrading fungi were ubiquitous in compost and rapidly colonised the surface of polyester PU coupons with significant deterioration. As the temperature decreased, fungal diversity in the compost and on the surface of the polyester PU coupons increased and selection of fungal community on the polyester PU coupons occurs that is different from the surrounding compost. PMID:24656620

Zafar, Urooj; Nzeram, Petrus; Langarica-Fuentes, Adrian; Houlden, Ashley; Heyworth, Alan; Saiani, Alberto; Robson, Geoff D

2014-04-01

214

Redox-Responsive, Core Cross-Linked Polyester Micelles  

PubMed Central

Monomethoxy poly(ethylene glycol)-b-poly(Tyr(alkynyl)-OCA), a biodegradable amphiphilic block copolymer, was synthesized by means of ring-opening polymerization of 5-(4-(prop-2-yn-1-yloxy)benzyl)-1,3-dioxolane-2,4-dione (Tyr(alkynyl)-OCA) and used to prepare core cross-linked polyester micelles via click chemistry. Core cross-linking not only improved the structural stability of the micelles but also allowed controlled release of cargo molecules in response to the reducing reagent. This new class of core cross-linked micelles can potentially be used in controlled release and drug delivery applications.

Zhang, Zhonghai; Yin, Lichen; Tu, Chunlai; Song, Ziyuan; Zhang, Yanfeng; Xu, Yunxiang; Tong, Rong; Zhou, Qin; Ren, Jie; Cheng, Jianjun

2013-01-01

215

Langmuir-Blodgett Films of Supported Polyester Dendrimers  

PubMed Central

Amphiphiles with a dendritic structure are attractive materials as they combine the features of dendrimers with the self-assembling properties and interfacial behavior of water-air affinities. We have synthesized three generations of polyester dendrimers and studied their interfacial properties on the Langmuir films. The behavior obtained was, as a rule, the lowest generation dendrimers behaving like traditional amphiphiles and the larger molecules presenting complicated isotherms. The Langmuir films of these compounds have been characterized by their surface pressure versus molecular area (?/A) and Brewster angle microscopy (BAM) observations.

Redon, Rocio; Carreon-Castro, M. Pilar; Mendoza-Martinez, F. J.

2012-01-01

216

Arginine-based polyester amide/polysaccharide hydrogels and their biological response.  

PubMed

An advanced family of biodegradable cationic hybrid hydrogels was designed and fabricated from two precursors via a UV photocrosslinking in an aqueous medium: unsaturated arginine (Arg)-based functional poly(ester amide) (Arg-UPEA) and glycidyl methacrylate chitosan (GMA-chitosan). These Arg-UPEA/GMA-chitosan hybrid hydrogels were characterized in terms of their chemical structure, equilibrium swelling ratio (Qeq), compressive modulus, interior morphology and biodegradation properties. Lysozyme effectively accelerated the biodegradation of the hybrid hydrogels. The mixture of both precursors in an aqueous solution showed near non-cytotoxicity toward porcine aortic valve smooth muscle cells at total concentrations up to 6mgml(-1). The live/dead assay data showed that 3T3 fibroblasts were able to attach and grow on the hybrid hydrogel and pure GMA-chitosan hydrogel well. Arg-UPEA/GMA-chitosan hybrid hydrogels activated both TNF-? and NO production by RAW 264.7 macrophages, and the arginase activity was also elevated. The integration of the biodegradable Arg-UPEA into the GMA-chitosan can provide advantages in terms of elevated and balanced NO production and arginase activity that free Arg supplement could not achieve. The hybrid hydrogels may have potential application as a wound healing accelerator. PMID:24530559

He, Mingyu; Potuck, Alicia; Zhang, Yi; Chu, Chih-Chang

2014-06-01

217

Engineered hypopharynx from coculture of epithelial cells and fibroblasts using poly(ester urethane) as substratum.  

PubMed

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; Zhu, Yabin

2013-01-01

218

Highly porous and mechanically robust polyester poly(ethylene glycol) sponges as implantable scaffolds.  

PubMed

The development of suitable scaffolds plays a significant role in tissue engineering research. Although scaffolds with promising features have been produced via a variety of innovative methods, there are no fully synthetic tissue engineering scaffolds that possess all the desired properties in one three-dimensional construct. Herein, we report the development of novel polyester poly(ethylene glycol) (PEG) sponges that display many of the desirable scaffold characteristics. Our novel synthetic approach utilizes acidchloride/alcohol chemistry, whereby the reaction between a hydroxyl end-functionalized 4-arm PEG and sebacoyl chloride resulted in cross-linking and simultaneous hydrogen chloride gas production, which was exploited for the in situ formation of highly interconnected pores. Variation of the fabrication conditions, including the precursor volume and concentration, allowed the pore size and structure as well as the compressive properties to be tailored. The sponges were found to possess excellent elastic properties, preserving their shape even after 80% compressive strain without failure. The benign properties of the sponges were demonstrated in an in vivo subcutaneous rat model, which also revealed uniform infiltration of vascularized tissue by 8weeks and complete degradation of the sponges by 16weeks, with only a minimal inflammatory response being observed over the course of the experiments. PMID:24561711

Ozcelik, Berkay; Blencowe, Anton; Palmer, Jason; Ladewig, Katharina; Stevens, Geoffrey W; Abberton, Keren M; Morrison, Wayne A; Qiao, Greg G

2014-06-01

219

Soft filamentous woven polyester arterial prosthesis from China.  

PubMed

Woven polyester arterial prostheses have traditionally been known for their tight construction and smooth surface which has limited their healing capacity and resulted in poor attachment of their internal and external capsules. A new woven prototype has recently been developed in the Peoples' Republic of China. Among its unique features are its high physical porosity, softness and flexibility. This study undertook a series of in vitro tests to characterize its structure and physical properties in comparison with four commercial polyester grafts of North American origin. In addition, an animal trial was completed in which the new prototype was implanted as an infrarenal aortic substitute in 20 dogs for periods ranging from 4 h to 12 month. The in vitro tests confirmed a unique lightweight, highly porous, satin weave construction. Because of its high water permeability, preclotting was necessary before implantation. Once preclotted and installed, no significant blood loss was observed, and 19 of the 20 grafts remained patent at the sacrifice. Rapid full-width healing was achieved with tightly bound capsules, and more extensive tissue ingrowth was observed. Further work is needed to evaluate its long-term durability as an arterial substitute. PMID:1854902

Rao, T J; Pan, C; Guidoin, R; Marceau, D; Roy, P E; King, M; Badour, B; Rui, J S; Cheng, H M; Li, C L

1991-04-01

220

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

PubMed Central

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

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

2010-01-01

221

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

PubMed

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

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

2011-10-01

222

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

223

Finishing of Polyester Fabrics with Cyclodextrins and Polycarboxylic Acids as Crosslinking Agents  

Microsoft Academic Search

CDs were grafted onto PET fibers by the intermediate of polycarboxylic acids thatplayed the role of crosslinking agents. We evidenced that grafting occurred despitethat no reaction could happen between the polycarboxylic acids and PET. It wasconcluded that the mode of grafting occurred through the formation of a crosslinkedcopolymer between PCA and CDs. This copolymer was not covalently fixed to thefibers,

B. Martel; M. Morcellet; D. Ruffin; L. Ducoroy; M. Weltrowski

2002-01-01

224

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

225

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

Microsoft Academic Search

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

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

2006-01-01

226

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.

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

2009-01-01

227

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

228

From polyesters to polyamides via O-N acyl migration: an original multi-transfer reaction.  

PubMed

A new strategy for the synthesis of polyamides from polyesters of hydroxyl-containing amino acids using a multi O-N acyl transfer reaction was developed. This original approach allowed the synthesis of three generations of polymers from the same starting monomer. The polymerization of N-benzyloxycarbonyl-serine and its ?-homologated derivative provided the Z-protected polyesters; then the water-soluble polycationic polyesters were obtained by removal of the Z-protecting group; and finally the polyamides were obtained by a base-induced multi O-N acyl transfer, both in aqueous or organic medium. The key step transfer reaction was monitored by the disappearance and appearance of characteristic NMR proton signals and IR bands of polyesters and polyamides. PMID:21604313

Tailhades, Julien; Blanquer, Sébastien; Nottelet, Benjamin; Coudane, Jean; Subra, Gilles; Verdié, Pascal; Schacht, Etienne; Martinez, Jean; Amblard, Muriel

2011-06-16

229

Evaluation of the Polyester/Polyethylene Badge Packet as an Identification Card.  

National Technical Information Service (NTIS)

With the advent of automated photographic badge making systems and automated access control systems, the need for new badge making strategies has become evident. In order to determine the suitability of the polyester/polyethylene badge packet for applicat...

L. J. Wright

1989-01-01

230

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

National Technical Information Service (NTIS)

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 sp...

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

1993-01-01

231

Interface and dynamic indentation of crosslinked polyester films  

NASA Astrophysics Data System (ADS)

The nanoindentation technique has drawn much interest recently for both its efficiency and versatility in measuring the mechanical properties of small volumes of materials and thin films. Since the unloading curve of polymers depends not only on the holding time but also on the unloading rate Hysitron Nanoindenter was used in our investigation of contact deformation of surfaces of polyester and polycarbonate supported on an aluminum substrate. Crosslinked polyesters with different gel concentration were produced on aluminum surfaces. Inter-phase plays a crucial role in composites. Stiffening and strengthening rely on load transfer across the interface, toughness is influenced by crack deflection/fiber pull-out, and ductility is affected by relaxation of peak stresses near the interface. Instead of strain softening with indentation depth observed in linear polymers, cross-linked polymers showed strain hardening. The extent of diffusion determines the extent of the interfacial region with the conformation loss of large molecules being higher than that of small molecules. Besides, considering the strain-hardening.an increasing stress is required to produce further plastic deformation after the material is strained beyond the yielding point, it is possible to separate the plastic deformation and the visco-elastic deformation and study them individually. Steady state deformation is compared with sinusoidal deformation relatable to differences in Tg from confinement effects. In cross-linked polymers, surface deformation is analyzed a three-layer model consisting of free surface layer, intermediate layer, and interface layer. Molecular relaxation dependence on molecular weight and cross-link density is shown.

Ahuja, Suresh

2008-03-01

232

Fabric radiators  

NASA Astrophysics Data System (ADS)

The design of large, high-temperature space radiators is still an evolving discipline. Researchers expanded the data base available to a designer by studying a novel class of radiators constructed of ceramic fabrics and/or composite materials. It appears that fabric radiators have features not available in more conventional radiator types, while offering the light weight and stowability of advanced radiators such as liquid droplet types. Experiments show that fabrics can be treated to become impermeable to the working fluid while retaining flexibility. This feature of fabrics, when allied to their low density, provides a material well-adapted to radiator construction.

Antoniak, Zenen I.; Jacox, Michael G.

233

Biodegradable polyurethane ureas with variable polyester or polycarbonate soft segments: effects of crystallinity, molecular weight, and composition on mechanical properties.  

PubMed

Biodegradable polyurethane urea (PUU) elastomers are ideal candidates for fabricating tissue engineering scaffolds with mechanical properties akin to strong and resilient soft tissues. PUU with a crystalline poly(?-caprolactone) (PCL) macrodiol soft segment (SS) showed good elasticity and resilience at small strains (<50%) but showed poor resilience under large strains because of stress-induced crystallization of the PCL segments, with a permanent set of 677 ± 30% after tensile failure. To obtain softer and more resilient PUUs, we used noncrystalline poly(trimethylene carbonate) (PTMC) or poly(?-valerolactone-co-?-caprolactone) (PVLCL) macrodiols of different molecular weights as SSs that were reacted with 1,4-diisocyanatobutane and chain extended with 1,4-diaminobutane. Mechanical properties of the PUUs were characterized by tensile testing with static or cyclic loading and dynamic mechanical analysis. All of the PUUs synthesized showed large elongations at break (800-1400%) and high tensile strength (30-60 MPa). PUUs with noncrystalline SSs all showed improved elasticity and resilience relative to the crystalline PCL-based PUU, especially for the PUUs with high molecular weight SSs (PTMC 5400 M(n) and PVLCL 6000 M(n)), of which the permanent deformation after tensile failure was only 12 ± 7 and 39 ± 4%, respectively. The SS molecular weight also influenced the tensile modulus in an inverse fashion. Accelerated degradation studies in PBS containing 100 U/mL lipase showed significantly greater mass loss for the two polyester-based PUUs versus the polycarbonate-based PUU and for PVLCL versus PCL polyester PUUs. Basic cytocompatibility was demonstrated with primary vascular smooth muscle cell culture. The synthesized families of PUUs showed variable elastomeric behavior that could be explained in terms of the underlying molecular design and crystalline behavior. Depending on the application target of interest, these materials may provide options or guidance for soft tissue scaffold development. PMID:21755999

Ma, Zuwei; Hong, Yi; Nelson, Devin M; Pichamuthu, Joseph E; Leeson, Cory E; Wagner, William R

2011-09-12

234

Biodegradable polyurethane ureas with variable polyester or polycarbonate soft segments: effects of crystallinity, molecular weight and composition on mechanical properties  

PubMed Central

Biodegradable polyurethane urea (PUU) elastomers are ideal candidates for fabricating tissue engineering scaffolds with mechanical properties akin to strong and resilient soft tissues. PUU with a crystalline poly(?-caprolactone) (PCL) macrodiol soft segment (SS) showed good elasticity and resilience at small strains (<50%), but showed poor resilience under large strains due to stress-induced crystallization of the PCL segments, with a permanent set of 677±30% after tensile failure. To obtain softer and more resilient PUUs, noncrystalline poly(trimethylene carbonate) (PTMC) or poly(?-valerolactone-co-?-caprolactone) (PVLCL) macrodiols of different molecular weights were used as SSs that were reacted with 1, 4-diisocyanatobutane and chain extended with 1, 4-diaminobutane. Mechanical properties of the PUUs were characterized by tensile testing with static or cyclic loading and dynamic mechanical analysis. All the PUUs synthesized showed large elongations at break (800–1400%) and high tensile strength (30–60 MPa). PUUs with non-crystalline SSs all showed improved elasticity and resilience relative to the crystalline PCL-based PUU, especially for the PUUs with high molecular weight SSs (PTMC 5400 Mn and PVLCL 6000 Mn), of which the permanent deformation after tensile failure was only 12±7% and 39±4%, respectively. The SS molecular weight also influenced the tensile modulus in an inverse fashion. Accelerated degradation studies in PBS containing 100 U/mL lipase showed significantly greater mass loss for the two polyester-based PUUs versus the polycarbonate-based PUU, and for PVLCL versus PCL polyester PUUs. Basic cytocompatibility was demonstrated with primary vascular smooth muscle cell culture. The synthesized families of PUUs showed variable elastomeric behavior that could be explained in terms of the underlying molecular design and crystalline behavior. Depending upon the application target of interest, these materials may provide options or guidance for soft tissue scaffold development.

Ma, Zuwei; Hong, Yi; Nelson, Devin M.; Pichamuthu, Joseph E.; Leeson, Cory E.; Wagner, William R.

2011-01-01

235

Water resistance and surface morphology of synthetic fabrics covered by polysiloxane/acrylate followed by electron beam irradiation  

NASA Astrophysics Data System (ADS)

Different synthetic fabrics were treated by electron beam surface coating with two formulations based on polydimethylsiloxane (PDMS) and polystyrene (PS) or poly(methyl methacrylate) (PMMA) oligomers. The water resistance properties were investigated in terms of the percentage of water repellency and absorption. Also, the surface coated fabrics were examined by scanning electron microscopy/microscope (SEM) connected to an energy dispersive X-ray (EDX) unit to determine the percentage atomic contents of elements. The results showed that the adhesion of the polysiloxane formulation to the surface depends largely on the kind of acrylate oligomer and textile fabric as indicated by the EDX analysis for silicon. In this regard, PDMS/PS formulation is more compatible with polyester and nylon-6 fabrics than PDMS/PMMA one. However, it was found that PDMS/PMMA formulation is more compatible with cotton/polyester blend than PDMS/PS. The SEM micrographs give further supports to the EDX analysis. On the basis of the percentage of water repellency and absorption, polyester fabric displayed the highest water resistance properties among the studied textile fabrics regardless of the used polysiloxane formulation.

El-Naggar, A. M.; Zohdy, M. H.; Mohammed, S. S.; Alam, E. A.

2003-04-01

236

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

Microsoft Academic Search

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

A Akdemir; N Tarakcioglu; A Avci

2001-01-01

237

A biodegradable poly(ester amine) based on polycaprolactone and polyethylenimine as a gene carrier  

Microsoft Academic Search

The aim of research was to develop and optimize delivery systems for plasmid DNA (pDNA) based on biodegradable polymers, in particular, poly(ester amine)s (PEAs), suitable for non-viral gene therapy. Poly(ester amine)s were successfully synthesized by Michael addition reaction between polycaprolactone (PCL) diacrylate and low molecular weight polyethylenimine (PEI). PEA\\/DNA complexes showed effective and stable DNA condensation with the particle sizes

Rohidas Arote; Tae-Hee Kim; You-Kyoung Kim; Soon-Kyung Hwang; Hu-Lin Jiang; Ho-Hyun Song; Jae-Woon Nah; Myung-Haing Cho; Chong-Su Cho

2007-01-01

238

Azobenzene Side-Chain Liquid Crystalline Polyesters with Outstanding Optical Storage Properties  

Microsoft Academic Search

A flexible azobenzene side-chain liquid crystalline (SCLC) polyester architecture employed for re- versible optical storage is described. The modular design allows four structural parameters to be in- dividually modied. These parameters: i- the methylene side-chain spacer length, ii- the substituent on azobenzene, iii- the methylene main-chain segment length, and iv- the polyester molecular mass, all influence the optical storage properties.

S. HVILSTED; M. PEDERSEN; N. C. R. HOLME; P. S. RAMANUJAN

239

Polymorphous Structures and Their Phase Relationships in a Main-Chain\\/Side-Chain Liquid Crystalline Polyester  

Microsoft Academic Search

A series of specially designed polyesters consisting aromatic main-chain\\/side-chain liquid crystalline (LC) polymers have been synthesized (PEFBP (n), where n is the number of methylene units in the side chains). For a PEFBP (n = 7) polyester, complicated polymorphism has been found, which includes three triclinic crystalline (Kt1, Kt2 and Kt3) phases, one highly ordered LC smectic phase (SKO) having

Jrjeng Ruan; Jason J. Ge; Anqiu Zhang; Jin Shi; Shy-Yeu Wang; Frank W. Harris; Stephen Z. D. Cheng

2002-01-01

240

Synthesis and Characterization of Novel Side-Chain Liquid-Crystalline Polyesters  

Microsoft Academic Search

Novel side-chain liquid-crystalline polyesters have been synthesized by direct polyesterification of phthalic anhydride, pentaerythritol, and 4-methoxy-4?-oxybiphenyl-substituted monocarboxylic acids with different lengths of spacers. The polyesters were characterized by H- and C-NMR spectroscopy, differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and optical polarized light microscopy. The polymerizations reached high conversion, the number-average molecular masses were 2900-3300 g\\/mol, and the polydispersity

Jouni Hamara; Kari Liinamaa; Robert Jansson; Franciska Sundholm

1994-01-01

241

Remodeling of patellar tendon grafts augmented with woven polyester after anterior cruciate ligament reconstruction in humans  

Microsoft Academic Search

:   Arthroscopic and histological evaluations of anterior cruciate ligament (ACL) grafts were made in 38 patients at various\\u000a intervals after reconstruction was performed with patellar tendons (PTs) augmented with woven polyester. The interval between\\u000a the surgery and the examinations ranged from 3 to 36 months (mean, 14.1 months). Biopsy specimens with woven polyester were\\u000a removed from the anterior mid-portion of

Yoshihito Nakayama; Yasumasa Shirai; Tetsuya Narita; Atsushi Mori

1999-01-01

242

Mesua ferrea L. seed oil based highly thermostable and biodegradable polyester\\/clay nanocomposites  

Microsoft Academic Search

Nanotechnology holds the prospective for pervasive and avant-garde changes to improve performance of materials. Mesua ferrea L. seed oil based highly thermostable and biodegradable polyester\\/clay nanocomposites have been prepared at different dose levels of nanoclay. The highly branched polyester resin was synthesized by condensation of 2,2-bis(hydroxymethyl) propionic acid with M. ferrea L. seed oil based carboxyl terminated pre-polymer. FTIR, rheometric,

Uday Konwar; Niranjan Karak; Manabendra Mandal

2009-01-01

243

Optimization of UV curable acrylated polyester-polyurethane\\/polysiloxane ceramer coatings using a response surface methodology  

Microsoft Academic Search

Dual UV and moisture curable acrylated polyester, organic\\/inorganic hybrid coatings were prepared using a coupling agent and\\u000a tetraethylorthosilicate (TEOS) oligomers. An acrylated polyester resin based on adipic acid, neopentyl glycol, trimethylolpropane,\\u000a and acrylic acid was synthesized. TEOS oligomers were prepared through the hydrolysis and condensation of TEOS with water\\u000a and 3-(triethoxysilyl)propylisocyanate (TEOSPI) was used as the coupling agent between organic

Ahmet Nebioglu; Mark D. Soucek

2006-01-01

244

In Vitro Biodegradation of Polyester-Based Plastic Materials by Selected Bacterial Cultures  

Microsoft Academic Search

A simple and rapid in vitro test was designed for the assessment of the biodegradation of polyester-based plastics by selected biodegrading bacterial strains. Variovorax paradoxus LMG 16137 was used for the degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Acidovorax avenae subsp. avenae LMG 17238 fo the synthetic-based polyesters poly(e-caprolactone) (PCL), poly(butylene succinate-co-butylene adipate), and a starch-PCL blend. Degradation by the bacteria was studied

Joris Mergaert; Kurt Ruffieux; Christophe Bourban; Virginie Storms; Wim Wagemans; Erich Wintermantel; Jean Swings

2000-01-01

245

Isothermal melt-crystallization and melting behavior for three linear aromatic polyesters  

Microsoft Academic Search

Isothermal crystallization and subsequent melting behavior for three different types of linear aromatic polyester, namely poly(ethylene terephthalate) (PET), poly(trimethylene terephthalate) (PTT), and poly(butylene terephthalate) (PBT), were investigated (with an emphasis on PTT in comparison with PET and PBT). These polyesters were different in the number of methylene groups (i.e. 2, 3, and 4 for PET, PTT, and PBT, respectively). Isothermal

Nujalee Dangseeyun; Phornphon Srimoaon; Pitt Supaphol; Manit Nithitanakul

2004-01-01

246

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

Microsoft Academic Search

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

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

1997-01-01

247

Third order nonlinear optical susceptibility of films of polydiacetylene-containing polyamides and polyesters  

Microsoft Academic Search

The third order nonlinear optical susceptibilities of cast films of diacetylene-containing polyamides, copolyamides and polyesters, were measured using degenerate four-wave mixing with picosecond pulses at 532 nm. The blue films of polyamides which contain aromatic polydiacetylene had ?(3) values of the order of 10-9–10-10 esu, while the orange films of polyesters having aliphatic polydiacetylenes showed ?(3) values of the order

Sergei Fomine; Esbaide Adem; Takeshi Ogawa

1995-01-01

248

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.

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

2011-01-01

249

Effect of Oil Palm Fibres Volume Fraction on Mechanical Properties of Polyester Composites  

NASA Astrophysics Data System (ADS)

The effect of two types of oil palm fibres (bunch and fruit) on mechanical properties of polyester composites is examined in the current work considering different volume fractions. Tensile, compression, and flexural properties of the composites were investigated. In addition to that, tensile strengths were calculated theoretically using Hirsch model. Scanning electron microscope (SEM) was used to observe the fracture mechanism of the specimens. Single fibre pull-out tests were performed to determine the interfacial shear strength between polyester resin and both types of oil palm fibres. Results revealed that both types of oil palm fibres enhanced the mechanical performance of polyester composites. At a higher volume fraction (40-50%), tensile strength of the polyester composite was improved, i.e., 2.5 times improvement in the tensile strength value. Experimental tensile strength values of oil palm bunch/polyester composites have a good correlation with the theoretical results, especially at low volume fractions of fibre. Flexural strength of polyester worsened with oil palm fibres at all volume fractions of fibre.

Yousif, B. F.

250

Fabric fastenings  

NASA Technical Reports Server (NTRS)

The study of aeronautical fabrics has led to a consideration of the best methods of attaching and fastening together such materials. This report presents the results of an investigation upon the proper methods of attaching fabrics to airplane wings. The methods recommended in this report have been adopted by the military services.

Walen, E D; Fisher, R T

1920-01-01

251

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.

Barker, R H

1975-01-01

252

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.

253

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

254

In vitro and in vivo degradation profile of aliphatic polyesters subjected to electron beam sterilization.  

PubMed

Degradation characteristics in response to electron beam sterilization of designed and biodegradable aliphatic polyester scaffolds are relevant for clinically successful synthetic graft tissue regeneration. Scaffold degradation in vitro and in vivo were documented and correlated to the macroscopic structure and chemical design of the original polymer. The materials tested were of inherently diverse hydrophobicity and crystallinity: poly(L-lactide) (poly(LLA)) and random copolymers from L-lactide and ?-caprolactone or 1,5-dioxepan-2-one, fabricated into porous and non-porous scaffolds. After sterilization, the samples underwent hydrolysis in vitro for up to a year. In vivo, scaffolds were surgically implanted into rat calvarial defects and retrieved for analysis after 28 and 91days. In vitro, poly(L-lactide-co-1,5-dioxepan-2-one) (poly(LLA-co-DXO)) samples degraded most rapidly during hydrolysis, due to the pronounced chain-shortening reaction caused by the sterilization. This was indicated by the rapid decrease in both mass and molecular weight of poly(LLA-co-DXO). Poly(L-lactide-co-?-caprolactone) (poly(LLA-co-CL)) samples were also strongly affected by sterilization, but mass loss was more gradual; molecular weight decreased rapidly during hydrolysis. Least affected by sterilization were the poly(LLA) samples, which subsequently showed low mass loss rate and molecular weight decrease during hydrolysis. Mechanical stability varied greatly: poly(LLA-co-CL) withstood mechanical testing for up to 182 days, while poly(LLA) and poly(LLA-co-DXO) samples quickly became too brittle. Poly(LLA-co-DXO) samples unexpectedly degraded more rapidly in vitro than in vivo. After sterilization by electron beam irradiation, the three biodegradable polymers present widely diverse degradation profiles, both in vitro and in vivo. Each exhibits the potential to be tailored to meet diverse clinical tissue engineering requirements. PMID:21316490

Dånmark, S; Finne-Wistrand, A; Schander, K; Hakkarainen, M; Arvidson, K; Mustafa, K; Albertsson, A-C

2011-05-01

255

Characterization of the Degradation Mechanisms of Lysine-derived Aliphatic Poly(ester urethane) Scaffolds  

PubMed Central

Characterization of the degradation mechanism of polymeric scaffolds and delivery systems for regenerative medicine is essential to assess their clinical applicability. Key performance criteria include induction of a minimal, transient inflammatory response and controlled degradation to soluble non-cytotoxic breakdown products that are cleared from the body by physiological processes. Scaffolds fabricated from biodegradable poly(ester urethane)s (PEURs) undergo controlled degradation to non-cytotoxic breakdown products and support the ingrowth of new tissue in preclinical models of tissue regeneration. While previous studies have shown that PEUR scaffolds prepared from lysine-derived polyisocyanates degrade faster under in vivo compared to in vitro conditions, the degradation mechanism is not well understood. In this study, we have shown that PEUR scaffolds prepared from lysine triisocyanate (LTI) or a trimer of hexamethylene diisocyanate (HDIt) undergo hydrolytic, esterolytic, and oxidative degradation. Hydrolysis of ester bonds to yield ?-hydroxy acids is the dominant mechanism in buffer, and esterolytic media modestly increase the degradation rate. While HDIt scaffolds show a modest (<20%) increase in degradation rate in oxidative medium, LTI scaffolds degrade six times faster in oxidative medium. Furthermore, the in vitro rate of degradation of LTI scaffolds in oxidative medium approximates the in vivo rate in rat excisional wounds, and histological sections show macrophages expressing myeloperoxidase at the material surface. While recent preclinical studies have underscored the potential of injectable PEUR scaffolds and delivery systems for tissue regeneration, this promising class of biomaterials has a limited regulatory history. Elucidation of the macrophage-mediated oxidative mechanism by which LTI scaffolds degrade in vivo provides key insights into the ultimate fate of these materials when injected into the body.

Hafeman, Andrea E.; Zienkiewicz, Katarzyna J.; Zachman, Angela L.; Sung, Hak-Joon; Nanney, Lillian B.; Davidson, Jeffrey M.; Guelcher, Scott A.

2010-01-01

256

Characterization of the degradation mechanisms of lysine-derived aliphatic poly(ester urethane) scaffolds.  

PubMed

Characterization of the degradation mechanism of polymeric scaffolds and delivery systems for regenerative medicine is essential to assess their clinical applicability. Key performance criteria include induction of a minimal, transient inflammatory response and controlled degradation to soluble non-cytotoxic breakdown products that are cleared from the body by physiological processes. Scaffolds fabricated from biodegradable poly(ester urethane)s (PEURs) undergo controlled degradation to non-cytotoxic breakdown products and support the ingrowth of new tissue in preclinical models of tissue regeneration. While previous studies have shown that PEUR scaffolds prepared from lysine-derived polyisocyanates degrade faster under in vivo compared to in vitro conditions, the degradation mechanism is not well understood. In this study, we have shown that PEUR scaffolds prepared from lysine triisocyanate (LTI) or a trimer of hexamethylene diisocyanate (HDIt) undergo hydrolytic, esterolytic, and oxidative degradation. Hydrolysis of ester bonds to yield ?-hydroxy acids is the dominant mechanism in buffer, and esterolytic media modestly increase the degradation rate. While HDIt scaffolds show a modest (<20%) increase in degradation rate in oxidative medium, LTI scaffolds degrade six times faster in oxidative medium. Furthermore, the in vitro rate of degradation of LTI scaffolds in oxidative medium approximates the in vivo rate in rat excisional wounds, and histological sections show macrophages expressing myeloperoxidase at the material surface. While recent preclinical studies have underscored the potential of injectable PEUR scaffolds and delivery systems for tissue regeneration, this promising class of biomaterials has a limited regulatory history. Elucidation of the macrophage-mediated oxidative mechanism by which LTI scaffolds degrade in vivo provides key insights into the ultimate fate of these materials when injected into the body. PMID:20864156

Hafeman, Andrea E; Zienkiewicz, Katarzyna J; Zachman, Angela L; Sung, Hak-Joon; Nanney, Lillian B; Davidson, Jeffrey M; Guelcher, Scott A

2011-01-01

257

Crosslinked Urethane Doped Polyester (CUPE) Biphasic Scaffold: Potential for In vivo Vascular Tissue Engineering  

PubMed Central

In vivo tissue engineering uses the body as a bioreactor for tissue regeneration, thus placing stringent requirements on tissue scaffolds which should be mechanically robust for immediate implantation without a long in vitro cell culture time. In addition to mechanical strength, vascular grafts fabricated for in vivo tissue engineering approach must have matching mechanical properties to the target tissues to avoid compliance mismatch, which is one of the reasons for graft failure. We recently synthesized a new generation of strong and elastic biodegradable crosslinked urethane-doped polyesters (CUPE) to address the challenge of developing soft, elastic yet strong biodegradable polymers. This study evaluated the tensile strength, burst pressure and suture retention of CUPE biphasic scaffolds to determine if the scaffolds met the requirements for immediate implantation in an in vivo tissue engineering approach. Additionally, we also examined the hemocompatibility and inflammatory potential of CUPE to demonstrate its potential in serving as a blood-contacting vascular graft material. Tensile strength of CUPE biphasic scaffolds (5.02±0.70 MPa) was greater than native vessels (1.43±0.60 MPa). CUPE scaffolds exhibited tunable burst pressure ranging from 1500 mmHg to 2600 mmHg, and adequate suture retention values (2.45±0.23 N). CUPE showed comparable leukocyte activation and whole blood clotting kinetics to poly(L-lactic acid) PLLA. However, CUPE incited a lesser release of inflammatory cytokines and was found to be non hemolytic. Combined with the mechanical properties and previously demonstrated anti-thrombogenic nature, CUPE may serve as a viable graft material for in vivo blood vessel tissue engineering.

Dey, Jagannath; Xu, Hao; Nguyen, Kytai Truong; Yang, Jian

2010-01-01

258

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

Microsoft Academic Search

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

Bradley Lyn Grunden

1999-01-01

259

Enzymatic Synthesis of Biobased Polyesters Using 2,5-Bis(hydroxymethyl)furan as the Building Block.  

PubMed

2,5-Bis(hydroxymethyl)furan is a highly valuable biobased rigid diol resembling aromatic monomers in polyester synthesis. In this work, it was enzymatically polymerized with various diacid ethyl esters by Candida antarctica Lipase B (CALB) via a three-stage method. A series of novel biobased furan polyesters with number-average molecular weights (Mn) around 2000 g/mol were successfully obtained. The chemical structures and physical properties of 2,5-bis(hydroxymethyl)furan-based polyesters were fully characterized. Furthermore, we discussed the effects of the number of the methylene units in the dicarboxylic segments on the physical properties of the furan polyesters. PMID:24835301

Jiang, Yi; Woortman, Albert J J; Alberda van Ekenstein, Gert O R; Petrovi?, Dejan M; Loos, Katja

2014-07-14

260

Preparation and the light transmittance of TiO 2 deposited fabrics  

Microsoft Academic Search

Nanoscale titanium dioxide (TiO2) films were deposited on the surface of polyester nonwovens by using direct current reactive magnetron sputtering. The effect\\u000a of oxygen flow on the surface structures and properties of the fabrics was investigated in this article. The surface morphology,\\u000a microstructure, and the chemical composition of TiO2-coated fibers were characterized by atomic force microscope, X-ray diffraction, and X-ray

Yang Xu; Ning Wu; Qufu Wei; Xiubiao Pi

2009-01-01

261

In situ hosphatizing coatings: Polyester-melamine baking enamels on aluminum alloys  

NASA Astrophysics Data System (ADS)

Currently, producing a good painted metal surface involves a lengthy and costly process. The metal surface is degreased, conversion coated, painted, and finally dried. The conversion coating is necessary when ordinary paints are used. An ordinary paint does not adhere very well to the bare metal surface. An ordinary paint does adhere to a conversion coating. The process for applying the conversion coating is time consuming, energy wasting, and often involves toxic compounds which are detrimental to the environment. A process which eliminates the use of a conversion coating is desirable. A novel technique of in-situ phosphatizing coatings is a possible alternative coating process. A single-step in-situ phosphatizing coating (ISPC) is formulated by predispersing a phosphatizing reagent into the paint. Ideally, the in-situ phosphatizing reagent (ISPR) reacts with the metal surface and simultaneously bonds with the paint film. An ISPC is formulated differently than an ordinary paint. Therefore, it adheres to a meted surface without the use of a conversion coating. The ISPR is acidic by nature. Polyester-melamine coatings are catalyzed by an acid catalyst. In a polyester-melamine coating the ISPR serves a dual purpose. First, the ISPR phosphatizes the metal surface. Second, the ISPR catalyzes the cross-linking reaction between polyester polyol and melamine in a polyester-melamine coating. The polyester-melamine ISPC is successfully applied to aluminum and steel. A comparison is made between the ISPC and the regular polyester-melamine coating which is catalyzed with p-toluenesulfonic acid. The resulting coatings are compared using electrochemical methods, thermal methods, and standard accelerated corrosion tests. The electrical equivalent circuits are also compared. The adhesion of the ISPC is far superior to the adhesion of the control on both the steel and the aluminum. The results suggest that polyester-melamine coatings can be altered into an ISPC. Also, the ISPR is able to catalyze the cross-linking reactions needed to cure the paint.

Whitten, Mary Catherine

1999-11-01

262

Poly(ester amide) blend microspheres for oral insulin delivery.  

PubMed

This study developed a novel oral insulin formulation centered on microspheres consisting of a blend of biodegradable poly(ester amide) (PEA). In the formulation, L-lysine-/L-leucine-based PEA with pendant COOH groups (PEA-COOH) was used as a pH-responsive material for the protection of insulin from the harsh environmental conditions of the stomach. Arginine-based PEA (Arg-PEA) was introduced to improve the intestinal absorption of the drug. The influence of both the hydrophobicity of PEA-COOH and the content of Arg-PEA was investigated in detail on microsphere surface morphology, drug loading, and the in vitro release profile of insulin. The PEA-COOH/Arg-PEA blend microspheres protected the loaded insulin in simulated gastric fluid and released insulin in a fast and sustained manner in simulated intestinal fluid. The in vivo test demonstrated that the oral administration of insulin-loaded PEA blend microspheres could effectively suppress the blood glucose level in diabetic rats for 10h, and the oral bioavailability was improved to 5.89+1.84% in healthy rats. These results indicate that the PEA blend microspheres are promising vehicles for the oral delivery of insulin. PMID:23876502

He, Pan; Liu, Huaiyu; Tang, Zhaohui; Deng, Mingxiao; Yang, Yan; Pang, Xuan; Chen, Xuesi

2013-10-15

263

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

264

Photocrosslinkable biodegradable elastomers based on cinnamate-functionalized polyesters.  

PubMed

Synthetic biodegradable elastomers are an emerging class of materials that play a critical role in supporting innovations in bioabsorbable medical implants. This paper describes the synthesis and characterization of poly(glycerol-co-sebacate)-cinnamate (PGS-CinA), a biodegradable elastomer based on hyperbranched polyesters derivatized with pendant cinnamate groups. PGS-CinA can be prepared via photodimerization in the absence of photoinitiators using monomers that are found in common foods. The resulting network exhibits a Young's modulus of 50.5-152.1kPa and a projected in vitro degradation half-life time between 90 and 140days. PGS-CinA elastomers are intrinsically cell-adherent and support rapid proliferation of fibroblasts. Spreading and proliferation of fibroblasts are loosely governed by the substrate stiffness within the range of Young's moduli in PGS-CinA networks that were prepared. The thermo-mechanical properties, biodegradability and intrinsic support of cell attachment and proliferation suggest that PGS-CinA networks are broadly applicable for use in next generation bioabsorable materials including temporary medical devices and scaffolds for soft tissue engineering. PMID:23567941

Zhu, Congcong; Kustra, Stephen R; Bettinger, Christopher J

2013-07-01

265

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

266

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

SciTech Connect

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

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

1982-01-01

267

Liquefaction of corn stover and preparation of polyester from the liquefied polyol.  

PubMed

This research investigated a novel process to prepare polyester from corn stover through liquefaction and crosslinking processes. First, corn stover was liquefied in organic solvents (90 wt% ethylene glycol and 10 wt% ethylene carbonate) with catalysts at moderate temperature under atmospheric pressure. The effect of liquefaction temperature, biomass content, and type of catalyst, such as H2SO4, HCl, H3PO4, and ZnCl2, was evaluated. Higher liquefaction yield was achieved in 2 wt% sulfuric acid, 1/4 (w/w) stover to liquefying reagent ratio; 160 degrees C temperature, in 2 h. The liquefied corn stover was rich in polyols, which can be directly used as feedstock for making polymers without further separation or purification. Second, polyester was made from the liquefied corn stover by crosslinking with multifunctional carboxylic acids and/or cyclic acid anhydrides. The tensile strength of polyester is about 5 MPa and the elongation is around 35%. The polyester is stable in cold water and organic solvents and readily biodegradable as indicated by 82% weight loss when buried in damp soil for 10 mo. The results indicate that this novel polyester could be used for the biodegradable garden mulch film production. PMID:16915670

Yu, Fei; Liu, Yuhuan; Pan, Xuejun; Lin, Xiangyang; Liu, Chengmei; Chen, Paul; Ruan, Roger

2006-01-01

268

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

269

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

Microsoft Academic Search

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

Anila Asif; Wenfang Shi; Xiaofeng Shen; Kangming Nie

2005-01-01

270

A preliminary identification and determination of characteristic volatile organic compounds from cotton, polyester and terry-towel by headspace solid phase microextraction gas chromatography-mass spectrometry.  

PubMed

Analysis of fifteen volatile organic compounds previously associated with laundry malodour has been investigated using headspace solid phase microextraction gas chromatography-mass spectrometry. Limits of detection (all determined on a 25 cm(2) area of fabric) ranged from a low of 0.4 ng (for guaiacol) through to a high of 28 ng (for 3-methylindole) on cotton; values on polyester ranged from a low of 0.7 ng (for dimethyl trisulfide) through to a high of 37 ng (for 3-methylindole); and, values on terry-towel ranged from a low of 1.7 ng (for guaiacol) through to a high of 157 ng (for ethyl benzene). There was a lack of correlation between the level of malodour and the occurrence of any of the VOCs detected; it could be that other compounds not evaluated in this study are responsible for malodour or it could be a collaborative effect of the various compounds studied. PMID:23683894

Stapleton, Katherine; Dean, John R

2013-06-21

271

Synthesis of high molecular weight polyesters via in vacuo dehydrogenation polymerization of diols.  

PubMed

The Milstein catalyst has proven to be highly effective for the conversion of alcohols to esters, as well as alcohols and amines to amides and polyamides. We have recently found that the catalyst's range can be extended to very efficient in vacuo dehydrogenation polymerization of ?,?-diols to generate polyesters. The gaseous hydrogen byproduct that is produced is easily removed to drive the equilibrium toward product, which leads to the formation of high molecular weight polymer (M(n) up to 145,000 g mol(-1)). This optimized methodology works well to polymerize diols with a spacer of six carbons or more. Diols with fewer carbons are cyclized to lactone; the dividing point is the dehydrogenation of 1,5-pentanediol, which leads to a mixture of polyester and lactone. Reported herein is the synthesis and characterization of five aliphatic polyesters prepared via this novel dehydrogenation polymerization approach. PMID:22173989

Hunsicker, David M; Dauphinais, Brian C; Mc Ilrath, Sean P; Robertson, Nicholas J

2012-02-13

272

Influence of nanosize clay platelets on the mechanical properties of glass fiber reinforced polyester composites.  

PubMed

Glass fiber reinforced polyester composite and hybrid nanoclay-fiber reinforced composites were prepared by hand lay-up process. The mechanical behavior of these materials and the changes as a result of the incorporation of both nanosize clay and glass fibers were investigated. Composites were prepared with a glass fibre content of 25 vol%. The proportion of the nanosize clay platelets was varied from 0.5 to 2.5 vol%. Hybrid clay-fiber reinforced polyester composite posses better tensile, flexural, impact, and barrier properties. Hybrid clay-fiber reinforced polyester composites also posses better shear strength, storage modulus, and glass transition temperature. The optimum properties were found to be with the hybrid laminates containing 1.5 vol% nanosize clay. PMID:17256365

Jawahar, P; Balasubramanian, M

2006-12-01

273

Ammonium Y zeolite applied as a thermochemolysis reagent for identification of polyethers and polyesters.  

PubMed

A potential thermochemolysis reagent has been tested for the pyrolysis gas chromatographic identification of polyether, polyester and polyether- or polyester-based thermoplastic polyurethane. The main advantage of ammonium Y zeolite over liquid reagents is that it does not react prior to pyrolysis, and its reactions have no incomplete products. The procedure of the thermochemolysis is as simple as running a pyrolysis-GC/MS analysis sampling a powder mixture of roughly equal mass of polymer and ammonium Y zeolite. The GC/MS chromatograms obtained show that the products of thermochemolysis are specific to the diol and dicarboxylic units of the polymer. It was observed that ethanal or 1,4-dioxane forms from ethylene oxide components of polyethers and polyesters, tetrahydrofuran from butylene oxide units, hexanedinitrile from adipate groups, and benzodinitrile from terephthalate groups. PMID:23237712

Blazsó, Marianne; Bozi, János

2013-01-01

274

An investigation of bending fatigue behavior for glass-fiber reinforced polyester composite materials  

Microsoft Academic Search

To investigate bending fatigue behaviors for glass-fiber reinforced polyester composite material, 800g\\/m2, 500g\\/m2, 300g\\/m2, and 200g\\/m2 glass-fiber woven and 225g\\/m2, 450g\\/m2, and 600g\\/m2 randomly distributed glass-fiber mat samples with polyester resin have been used. The samples have been produced by the RTM (Resin Transfer Molding) method and the samples have been cut down with directions of 0\\/90°, ±45°. As results

Raif Sakin; ?rfan Ay; Ramazan Yaman

2008-01-01

275

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

276

Structure development of polyesters and their blends in film formation processes  

NASA Astrophysics Data System (ADS)

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

Song, Kwangjin

277

Fabrication technology  

NASA Astrophysics Data System (ADS)

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 do the following: (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 U.S. 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

278

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

279

Synthesis and analysis of photoresponsive side chain dendritic polyesters  

NASA Astrophysics Data System (ADS)

The incorporation of a photoresponsive "smart" materials that can reversibly change shape or properties by simple photoirradiation, allow for components that are lighter and capable of responding faster than current adaptive materials. The azobenzene molecule observes an effective size differential when exposed to UV light on the order of ˜3.5 A as it converts from a stable trans isomer to an excited cis isomer. The isomerization is photoreversible when attenuated with visible light. Incorporating the azobenzene moiety into an extended polymer chain has resulted in such problems as lack of free volume available for the azobenzene to efficiently isomerize, increase in polymer chain rigidity, and the propensity for the azobenzene moieties to aggregate when forced into proximity with one another. Banthia et al. developed and incorporated a PAMAM dendritic wedge diol with a diacyl chloride azobenzene to form side chain dendritic polyesters (SCDPE). Twelve SCDPE polymers were prepared in groups of increasing dendrimer generations (1st-3rd) and decreasing azobenzene concentrations (100%, 50%, 10%, and 5%) to confirm the proposed hypothesizes that the bulky dendrimer substituents provided efficient free volume to inhibit aggregation and increase the polymer photoresponse, and the increased flexibility gained from the decrease in azobenzene concentration would also elicit an increase in photoresponse. The polymers were analyzed as both solutions and as spin coated thin films. Real time UV-Vis spectroscopy isomerization kinetic showed that increasing the dendrimer generations for both solution and films increased the SCDPE polymer photoresponse. The decrease in azobenzene concentration resulted in increased photoresponse SCDPE polymer solutions, but showed no potential for SCDPE polymer films. Atomic force microscopy (AFM) was used to image 2nd and 3rd generation (100%) azobenzene SCDPE films with photoinduced surface relief gratings patterned on their surface with non polarized light. The difference in height variations (6 nm and 18 nm, respectively) confirmed the isomerization kinetic data that the 3 rd generation, 100% azobenzene film had the greatest potential for future applications. The films were also shown to be photoreversible with visible light which suggesting they have the potential to applications on photonic and optical photoresponsive devices.

Galgano, Joshua J.

280

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

Microsoft Academic Search

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

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

2010-01-01

281

After-Waxing of Sized Cotton and Polyester-Cotton Blend Yarns.  

National Technical Information Service (NTIS)

After-waxing of filament yarns is a common practice in the synthetic weaving industry. However, very little information is available on after-waxing of spun cotton and polyester/cotton blend warps. Analysis of different softeners has been carried out to f...

1973-01-01

282

Biodegradable polyester blend and copolyesters studied by positron annihilation and other methods  

Microsoft Academic Search

Two polyesters, i.e. an aromatic one: poly(butylene terephthalate) - PBT and an aliphatic one: poly(?- -caprolactone) - PCL were mixed in melt to obtain a biodegradable product. DSC, 1 H NMR, SEM, WAXS, SAXS, BOD and PALS measurements were performed to study the homopolymers as well as their physical blend and copolyesters. The latter were obtained due to the transesterification

Adam Kiersnowski

283

Hydrogen Bonding Structure in Hyperbranched Aliphatic Polyesters Studied by MD Simulations  

Microsoft Academic Search

Hyperbranched aliphatic polyesters based on dimethoxy propionic acid (bis-MPA) as the repeating unit and ethoxylated pentaerythritol as the tetrafunctional core gained widespread attention due to their unusual structure and properties. These globular macromolecules possess a large number of hydroxyl functional groups in particular on their periphery. These hydroxyl groups interact readily through hydrogen bonding (HB) and form clusters responsible for

Brian Olson; Mukul Kaushik; Sergei Nazarenko

2009-01-01

284

MICROWAVE AND REFLECTION PROPERTIES OF PALM SHELL CARBON-POLYESTER CONDUCTIVE COMPOSITE ABSORBER  

Microsoft Academic Search

The microwave properties of permittivity, ? and loss tangent, tan ? of conductive composite utilizing palm shell carbon mixed with unsaturated polyester resin were studied in the 8 to 12 GHz frequency range. The measurement of ? and tan ? emphasize on the influence of carbon concentration (mass %) of palm shell pyrolysed at 600, 700 and 800°C. It was

AHMAD ANAS YUSOF; WAN KHAIRUDDIN WAN ALI; THAREK ABD

2007-01-01

285

Fatigue damage and environment interaction of polyester aluminized glass fiber composites  

Microsoft Academic Search

Aluminized glass fiber composites in a polyester matrix were used in this work in an attempt to study their fatigue resistance under both dry and water saturated ambient conditions (compared to conventional glass fiber composites). These composites, containing specially modified fibers, exhibit increased thermal and electrical conduction properties whilst still being potentially adequate for many structural applications. The fatigue tests

J. M. Ferreira; J. T. B. Pires; J. D. Costa; O. A. Errajhi; M. Richardson

2007-01-01

286

Influence of pores on the quality of a silicon polyester coated galvanised steel system  

Microsoft Academic Search

Silicon polyester coated steel plate is frequently used because of its good corrosion resistance under various conditions. However, if the application of the coating and\\/or the curing process is carried out too fast, evaporating solvent is enclosed in the coating, forming pores. The aim of this study is to investigate the influence of different types of pores on the corrosion

V Lavaert; M De Cock; M Moors; E Wettinck

2000-01-01

287

Nanofiltration thin-film composite polyester polyethersulfone-based membranes prepared by interfacial polymerization  

Microsoft Academic Search

Nanofiltration polyester thin-film composite membranes have been prepared by interfacial polymerization using commercial polyethersulfone membrane support. Different monomer bisphenol A (BPA) concentrations in the aqueous solution and various interfacial polymerization times in the organic solution containing trimesoyl chloride (TMC) were studied. The success of the conducted interfacial polymerization procedure was corroborated by FTIR-ATR. Irreversible fouling of both the unmodified polyethersulfone

M. N. Abu Seman; M. Khayet; N. Hilal

2010-01-01

288

Formation of a surface covalent organic framework based on polyester condensation.  

PubMed

The reaction between 1,3,5-tris(4-hydroxyphenyl)benzene and benzene-1,3,5-tricarbonyl trichloride leads to polyester condensation and formation of a novel COF on an Au(111) surface. The characterization performed in situ by means of variable temperature STM and XPS reveals the formation of an array of hexagonal cavities with ca. 2 nm size. PMID:22555383

Marele, Antonela C; Mas-Ballesté, Rubén; Terracciano, Luigi; Rodríguez-Fernández, Jonathan; Berlanga, Isadora; Alexandre, Simone S; Otero, Roberto; Gallego, José M; Zamora, Félix; Gómez-Rodríguez, José M

2012-07-11

289

Effect of Chemical Modification on the Mechanical and Electrical Properties of Banana Fiber Polyester Composites  

Microsoft Academic Search

Banana fiber obtained from the sheath of the banana plant, Musa sapientum, has been used in the preparation of composites with polyester matrix. The effect of fiber loading on the dielectric constant, volume resistivity, and dielectric loss factor of the composites were determined with special reference to the effect of frequency. The fibers were modified chemically in order to have

L. A. Pothan; C. N. George; M. Jacob; S. Thomas

2007-01-01

290

Outgassing rate of Reemay Spunbonded Polyester and DuPont Double Aluminized Mylar  

Microsoft Academic Search

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

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

1993-01-01

291

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

Microsoft Academic Search

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

K. S. Rebeiz

1996-01-01

292

New Hybrid Materials Based on Modified Halloysite and Unsaturated Polyester Resin  

Microsoft Academic Search

New hybrid materials based on unsaturated polyester resin and modified halloysite with different coupling agents were synthesized. The effect of functional groups grafted on the surface of halloysite against the properties of the final hybrids was studied using different characterization methods. The results of dynamic mechanical analyses showed that the glass transition temperature value of hybrids was strongly influenced by

Sorina Alexandra Gârea; Adi Ghebaur; Floriana Constantin; Horia Iovu

2011-01-01

293

Polyurethane–unsaturated polyester interpenetrating polymer networks: thermal and dynamic mechanical thermal behaviour  

Microsoft Academic Search

A series of simultaneous interpenetrating polymer networks, IPNs, based on a polyurethane and an unsaturated polyester resin is studied. The curing process was followed using differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). The IPNs were seen to crosslink completely and the kinetics of the curing process were modified greatly, accelerating with respect to the pure homopolymers. The process

X. Ramis; A. Cadenato; J. M. Morancho; J. M. Salla

2001-01-01

294

Analysis of Dry Sliding Wear Behavior of Red Mud Filled Polyester Composites using the Taguchi Method  

Microsoft Academic Search

Red mud is an industrial waste generated during the production of alumina by Bayer's process. Using this red mud as the filler, particulate reinforced polyester composites have been prepared and their dry sliding wear behavior has been studied experimentally. For this a standard pin- on-disc test set-up and Taguchi's orthogonal arrays were used. Taguchi's experimental design method eliminates the need

ALOK SATAPATHY; AMAR PATNAIK

2008-01-01

295

Toughening mechanisms of modified unsaturated polyester with novel liquid Polyurethane rubber  

Microsoft Academic Search

Unsaturated polyester (UPE) has been toughened by incorporating novel liquid polyurethane (PU) rubber. PU rubber was synthesized using toluene di-isocyanate and polyols such as poly (propylene glycol) and poly (tetramethylene ether) glycoi, whose molecular weights vary from 650 to 4000. Particle size was varied from 0.1 to 3 µm by changing the polyol and the molecular weight of PU rubber,

D. S. Kim; K. Cho; J. H. An; C. E. Park

1994-01-01

296

Surface modification of polyester to produce a bacterial cellulose-based vascular prosthetic device  

NASA Astrophysics Data System (ADS)

The surface of medical grade polyesters was modified to impart hydrophilic character for attachment to bacterial synthesized cellulose to produce a vascular prosthetic device. The polyesters were treated with UV/ozone, air plasma, and nitrogen plasma for various lengths of time. The unmodified and modified surfaces were analyzed by X-ray photoelectron spectroscopy (XPS) and advancing contact angle measurements. The surfaces were then coated with bacterial produced cellulose to study adhesion properties through tensile testing (peel testing). UV/ozone and plasma treatment XPS results indicated an increase in the oxygen concentration in the form of C sbnd O(H) on the treated polyester surfaces. The treatment time to reach steady state in the case of air and nitrogen plasmas took the order of seconds, while 7 min and longer were required for UV/ozone treatment. Peel strength tests to measure adhesion of modified polyester to cellulose reached their maximum values when the C sbnd O(H) concentrations were at the highest level. It was also at this level that the contact angle measurements showed no further decrease.

Charpentier, Paul A.; Maguire, Anne; Wan, Wan-kei

2006-07-01

297

Method to determine the thermal expansion of epoxies, inorganic cements and polyester resins at cryogenic temperatures  

NASA Astrophysics Data System (ADS)

An apparatus for measuring the integral thermal expansions at cryogenic temperatures is described. The thermal expansions are given for a number of commercial epoxy resins, commercial polyester resins and inorganic cements. A method to reduce the thermal expansion of the resins by the use of quartz powder fillers is reported.

Sereinig, W.; Gross, F.

298

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

Microsoft Academic Search

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

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

2005-01-01

299

Requirements on bacterial polyesters as future substitute for conventional plastics for consumer goods  

Microsoft Academic Search

Bacterial polyesters such as polyhydroxybutyrate (PHB) or polyhydroxyalkanoates (PHAs) have to pass the following requirements to be accepted on a large scale: (i) they have to fulfil an urgent market need: (ii) they require that new and efficient composting systems are installed in urban areas; (iii) they have to complete with the present plastics as far as quality and processing

Urs. J. Hänggi

1995-01-01

300

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

Code of Federal Regulations, 2013 CFR

...purpose of this section, partial phosphoric acid esters of polyester resins are prepared by...of the resin thus produced with phosphoric acid anhydride to produce a resin having an acid number of 81 to 98 and a phosphorus content of...

2013-04-01

301

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

Code of Federal Regulations, 2010 CFR

...purpose of this section, partial phosphoric acid esters of polyester resins are prepared by...of the resin thus produced with phosphoric acid anhydride to produce a resin having an acid number of 81 to 98 and a phosphorus content of...

2010-01-01

302

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

Code of Federal Regulations, 2010 CFR

...purpose of this section, partial phosphoric acid esters of polyester resins are prepared by...of the resin thus produced with phosphoric acid anhydride to produce a resin having an acid number of 81 to 98 and a phosphorus content of...

2009-04-01

303

The use of recycled printed circuit boards as reinforcing fillers in the polyester composite  

Microsoft Academic Search

The feasibility of using recycled printed circuit boards (PCB) as reinforcing fillers in manufacturing unsaturated polyester (UP) composites was studied using differential scanning calorimetry (DSC), and mechanical test. The concentrations of Cu leached from the molded products were also tested. From the DSC measurement, it was obtained that the addition of PCB affected the free radical reaction of the UP

S. G. Hong; S. H. Su

1996-01-01

304

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

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

305

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

306

Analysis of polyester and epoxy composite shells subjected to axial crushing  

Microsoft Academic Search

Round cylindrical and conical shells made of short randomly oriented glass fibre mats with polyester resin and tubes made of 0190 continuous glass fiber mats with epoxy resin were subjected to axial compression in an Instron machine. The different failure modes of these shells and their energy absorbing characteristics were studied.Based on the experimental observations, an analytical procedure is established

NK Gupta; R. Velmurugan

2000-01-01

307

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

308

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

PubMed

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

Liu, Lifen; Zhao, Chuanqi; Yang, Fenglin

2012-04-15

309

Chemical deposition of photosensitive CdS thin films on polyester foils  

Microsoft Academic Search

Cadmium sulfide thin films were deposited on polyester foils (PE) by chemical bath deposition using triethanolamine (TEA) and citrate (Citrate) as ligand for complexation with cadmium ions. X-ray diffraction (XRD) analyses show that the CdS films deposited by the TEA method possess hawleyite (cubic) structure, but crystallinity is not noticeable in the films deposited by the Citrate method. An overgrowth

Hailin Hu; P. K. Nair

1995-01-01

310

Functionalization of cellulose-containing fabrics by plasma and subsequent metal salt treatments.  

PubMed

In order to upgrade the UV-protection and antibacterial functional properties of cotton/polyester (80/20), cotton/linen (50/50) and linen/viscose-polyester (50/50) fabric blends, they were treated with different plasma gases (oxygen, air, and argon) followed by subsequent treatment with certain metal salts namely Zn-acetate, Cu-acetate, Al-chloride, and Zr-oxychloride. The obtained results show that the type of plasma gas, the kind of metal salt as well as the nature of the treated substrate play an important role in the extent of enhancing the demanded functional properties. Oxygen plasma treatment followed by Cu-acetate or Zn-acetate treatment gives the best UV-protection or antibacterial activity respectively, keeping other parameters constant. The surface morphology of some untreated and plasma-treated samples was also analyzed by SEM. PMID:22840019

Ibrahim, N A; Eid, B M; Youssef, M A; El-Sayed, S A; Salah, A M

2012-10-01

311

Model calibration for pressure drop in a pulse-jet cleaned fabric filter  

NASA Astrophysics Data System (ADS)

A model based on Darcy's law allows prediction of pressure drop in a pulse-jet cleaned fabric filter. The model considers the effects of filtration velocity, dust areal density added during one filtration cycle, and pulse pressure. Data used to calibrate the model were collected in experiments with three fabric surface treatments and three dusts conducted at three filtration velocities, for a total of 27 different experimental conditions. The fabric used was polyester felt with untreated, singed, or PTFE-laminated surface. The dusts used were granite, limestone and fly ash. Filtration velocities were 50,75 and 100 mm s -1. Dust areal density added during one filtration cycle was constant, as was pulse pressure. Under these conditions, fabric surface treatment alone largely determined the values for two of the three constants in the model; the third constant depends on pressure drop characteristics of the venturi at the top of each filter bag.

Koehler, John L.; David, Leith

312

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

National Technical Information Service (NTIS)

In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 19...

A. B. England D. N. Thompson F. J. Loge J. P. Fladers K. A. Wiedeman R. W. Emerick

2010-01-01

313

Morphology-structure of oriented noncrystalline polyester studied by two-dimensional wide angle x-ray scattering  

Microsoft Academic Search

Morphology-structure of oriented noncrystalline polyesters has been studied using the parameters changes of the broad peaks in wide angle x-ray scattering (WAXS) with azimuth angles. Two-dimensional WAXS show that the oriented noncrystalline polyester is made up of long plane-like chains arranged in opposition to each other; and these chains are composed of oriented atomic distances with the chain axes parallel

Chen Ji-zhou; Wang Jun-qiao; Han Fu-tian

1995-01-01

314

Thixotropic behavior of metal-containing coordination polymers: Melt viscosity of neutral aliphatic polyesters with Zn carboxylates  

Microsoft Academic Search

The viscosity behavior of polymer melts containing complexes formed between the neutralized polyester poly(diethylene glycol-co-succinic acid) and Zn acetates is discussed. The melt viscosity of these materials increases with the concentration of metal ions, and shows strong thixotropy and shear thinning. This behavior is attributed to the formation of coordination bonds between the electron donor groups within the polyester chain,

G. Liu; B. White; I. Vancso-Szmercsanyi; G. J. Vancso

1996-01-01

315

Investigation of the properties of UV-curing acrylate-terminated unsaturated polyester coatings by utilizing an experimental design methodology  

Microsoft Academic Search

The effect of the extent of internal unsaturation and branching on the properties of the acrylated polyester films was investigated.\\u000a Polyester acrylate resins were prepared based on adipic acid, maleic anhydride, neopentyl glycol, trimethylolpropane, and\\u000a acrylic acid. As the reactive diluent, trimethylolpropane triacrylate (TMPTA) was used. Experiments were planned according\\u000a to the three-factor, three-level Box-Behnken design. Coating film properties were

Ahmet Nebioglu; Mark D. Soucek

2007-01-01

316

Determinationand comparison of the plane stress essentialwork of fracture of three polyestersPET, PPT and PBT  

Microsoft Academic Search

The essential work of fracture\\u000a (EWF) method has been used to study the relationship between molecular structure\\u000a and thin film fracture toughness for three ductile polyesters at ambient temperature.\\u000a The fracture toughness of PPT is of particular interest. Successful fracture\\u000a characterisation of thin film polyesters has been achieved by the EWF method\\u000a using double edge notched tension (DENT) specimens. The

L. Vincent; S. N. Connolly; F. Dolan; P. H. Willcocks; S. A. A. Jayaweera; R. Pendlebury

2006-01-01

317

Volatile organics off-gassed among tobacco-exposed clothing fabrics.  

PubMed

This work evaluates the characteristics of short-term release of volatile and semi-volatile organic chemicals from clothing fabrics that are exposed to environmental tobacco smoke (ETS). Various fabrics were concurrently exposed to ETS in a controlled facility, and the chemicals off-gassed were sampled using solid phase micro-extraction coupled with GC/MS analysis. Toluene-reference concentration (TRC) was calculated for nine selected chemicals and compared. The number of chemicals identified from ETS-exposed fabrics ranged from 13 (polyester and acetate) to 32 (linen). All fabrics off-gassed formaldehyde, tetradecanoic acid and n-hexadecanoic acid, while seven out of eight fabrics emitted furfural, benzonitrile, naphthalene and decanal. Natural fibers of plant origin (cotton and linen) off-gassed higher concentrations (TRC>100 ?g/l) of chemicals that have low molecular weight (~100 or less) than did natural fibers of animal origin (wool and silk) and synthetic fibers. Conversely, wool and silk off-gassed more chemicals that are of high molecular weight (>200), such as TDA (TRC>100 ?g/l) and n-HDA (TRC>500 ?g/l), than did other fabrics. Fabric structure (for a particular material) significantly affects chemical off-gassing. Cotton typically used for polo shirt (knitted) off-gassed significantly (p<0.05) higher TRC for chemicals with molecular weight of ~100 (such as furfural) than did other cottons of woven style. The dyeing of fabric (white vs. black) had a limited effect on emission, while increasing contact time with ETS increased the intensity of chemical emissions. The mean TRC for cotton exposed for 12 min was nearly doubled than those exposed for 8min, but no difference existed for polyester. PMID:21852036

Chien, Yeh-Chung; Chang, Cheng-Ping; Liu, Zheng-Zhe

2011-10-15

318

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

319

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

320

Immobilization of DNA Aptamers on Polyester Cloth for Antigen Detection by Dot Blot Immunoenzymatic Assay (Aptablot)  

PubMed Central

A simple dot blot immunoenzymatic assay system was developed using polyester cloth coated with an oligo-DNA aptamer to provide a high-affinity macroporous surface for the efficient capture of a model protein analyte (thrombin) in complex sample matrices such as foods. Bound thrombin was detected immunoenzymatically using a peroxidase-linked antithrombin antibody and a chromogenic substrate. A unique feature of this approach, which we have termed “aptablot,” is the facile immobilization of DNA aptamers on the polyester surface by cross-linking with a brief exposure to ultraviolet light, and the simple assay format obviating the need for specialized instruments. The assay principle described herein should be broadly applicable to many situations where analytes must be detected in complex samples, with the main limiting factor being the availability of suitable DNA aptamers.

Smiley, Sally; DeRosa, Maria; Blais, Burton

2013-01-01

321

Photooxidation mechanism of aliphatic crosslinked polyesters used for flat steel coating  

NASA Astrophysics Data System (ADS)

The study of the photooxidation mechanism of crosslinked polyesters used for flat steel coating can be based on the analysis of photoproducts at the molecular scale: these photoproducts are formed in the matrix under exposure in an accelerated photoageing chamber SEPAP 12-24. Hydroxy functionalized aliphatic polyesters crosslinked with highly methoxy methylated melamines or aliphatic blocked polyisocyanates have been examined. The different photoproducts involved in the oxidative evolution have been identified using FTIR spectroscopy and chemical derivatization treatments. Physical changes have been examined by DMTA analysis on free polymer films. Mechanisms accounting for the photooxidation of each crosslinked system was proposed, involving both chain oxidation and crosslink scissions. Crosslinking due to radical recombinations have been shown to occur in the oxidized matrix.

Delorme, Pierre; Lemaire, Jacques; Carrara, Francçoise; Bonnebat, Claude

1996-01-01

322

Plastics from bacteria and for bacteria: poly(beta-hydroxyalkanoates) as natural, biocompatible, and biodegradable polyesters.  

PubMed

Hence, PHB belongs to the family of poly(beta-hydroxyalkanoates), PHA, all of which are usually formed as intracellular inclusions under unbalanced growth conditions. Recently, it became of industrial interest to evaluate PHA polyesters as natural, biodegradable, and biocompatible plastics for a wide range of possible applications such as surgical sutures or packaging containers. For industrial applications, the controlled incorporation of repeating units with different chain lengths into a series of copolymers is desirable in order to produce polyesters with a range of material properties because physical and chemical characteristics depend strongly on the polymer composition. Such "tailormade" copolymers can be produced under controlled growth conditions, in that if a defined mixture of substrates for a certain type of microorganisms is supplied, a well defined and reproducible copolymer is formed. PMID:2126418

Brandl, H; Gross, R A; Lenz, R W; Fuller, R C

1990-01-01

323

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

324

Photooxidation mechanism of aliphatic crosslinked polyesters used for flat steel coating  

SciTech Connect

The study of the photooxidation mechanism of crosslinked polyesters used for flat steel coating can be based on the analysis of photoproducts at the molecular scale: these photoproducts are formed in the matrix under exposure in an accelerated photoageing chamber SEPAP 12{endash}24. Hydroxy functionalized aliphatic polyesters crosslinked with highly methoxy methylated melamines or aliphatic blocked polyisocyanates have been examined. The different photoproducts involved in the oxidative evolution have been identified using FTIR spectroscopy and chemical derivatization treatments. Physical changes have been examined by DMTA analysis on free polymer films. Mechanisms accounting for the photooxidation of each crosslinked system was proposed, involving both chain oxidation and crosslink scissions. Crosslinking due to radical recombinations have been shown to occur in the oxidized matrix. {copyright} {ital 1996 American Institute of Physics.}

Delorme, P.; Lemaire, J. [Laboratoire de Photochimie Moleculaire et Macromoleculaire URA CNRS 433 Ensemble Universitaire des Cezeaux F-63177 Aubiere Cedex (France); Carrara, F.; Bonnebat, C. [CED Sollac, BP 109 F-60761 Montataire Cedex (France)

1996-01-01

325

Immobilization of DNA aptamers on polyester cloth for antigen detection by dot blot immunoenzymatic assay (aptablot).  

PubMed

A simple dot blot immunoenzymatic assay system was developed using polyester cloth coated with an oligo-DNA aptamer to provide a high-affinity macroporous surface for the efficient capture of a model protein analyte (thrombin) in complex sample matrices such as foods. Bound thrombin was detected immunoenzymatically using a peroxidase-linked antithrombin antibody and a chromogenic substrate. A unique feature of this approach, which we have termed "aptablot," is the facile immobilization of DNA aptamers on the polyester surface by cross-linking with a brief exposure to ultraviolet light, and the simple assay format obviating the need for specialized instruments. The assay principle described herein should be broadly applicable to many situations where analytes must be detected in complex samples, with the main limiting factor being the availability of suitable DNA aptamers. PMID:24288595

Smiley, Sally; Derosa, Maria; Blais, Burton

2013-01-01

326

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

327

Phase transitions and structural parameters of HIQ-40 liquid crystalline co-polyester  

Microsoft Academic Search

We describe the impact of thermal treatment on the structure and phase transitions of the liquid crystalline aromatic co-polyester, HIQ-40, comprising 40mol% p-hydroxybenzoic acid (H), 30mol% isophthalic acid (I), and 30mol% p-hydroquinone (Q). Simultaneous, real-time wide and small angle X-ray scattering (WAXS, SAXS), differential scanning calorimetry, and optical ellipsometry were used to study initially isotropic, amorphous films of HIQ-40. Films

Georgi Georgiev; Nathan Gilfoy; Peggy Cebe; Malcolm Capel

2004-01-01

328

COMMUNICATION TO THE EDITOR Chiral Compounds from Bacterial Polyesters: Sugars to Plastics to Fine Chemicals  

Microsoft Academic Search

A novel and efficient method for the production of enantiomerically pure (R)-(-)-hydroxycarboxylic acids by in vivo depolymerization of microbial polyester poly- hydroxyalkanoates (PHAs) was developed. Using this method, s everal m odel c ompounds, (R)-(-)-3- hydroxyalkanoic acids, consisting of 4 to 12 carbon at- oms, and (R)-(-)-3-hydroxy-5-phenylvaleric acid, could be prepared. In particular, (R)-(-)-3-hydroxybutyric acid could be efficiently prepared by

Sang Yup Lee; Young Lee; Fulai Wang

329

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

330

Characterisation of products from the recycling of glass fibre reinforced polyester waste by pyrolysis  

Microsoft Academic Search

A thermoset polyester\\/styrene copolymer reinforced with glass fibre was pyrolysed in a fixed-bed reactor at 450 °C. The main gases evolved were CO and CO2, which accounted for more than 75vol% of the total gas composition. Other gases identified were H2, CH4 and other hydrocarbons from C2 to C4. The properties of the pyrolytic oil, including calorific value, viscosity and

Adrian M Cunliffe; Paul T Williams

2003-01-01

331

Cycle history data and elongation characteristics for polyester and aramid wire-lay construction ropes  

Microsoft Academic Search

High performance ropes have unique properties that are derived from their fiber and construction. Wire-lay construction rope manufactured from 1W81 polyester with SeaGuard(R) finish and Kevlar(R) 29 aramid are observed in this study while experiencing 250,000+ cycles of tension-tension fatigue. The results indicate general behavioral trends. The numerical data obtained can be used in computer models to evaluate the appropriate

E. W. Huntley

1997-01-01

332

Study on the control of the compositions and properties of a biodegradable polyester elastomer  

Microsoft Academic Search

Biodegradable polyester elastomers are widely reported to be applied in varied biomedical fields. In this paper, we attempt to investigate how both the thermal-curing time and molar ratio of the monomers affect the final compositions and properties of the novel poly(glycerol-sebacate-citrate) (PGSC) elastomers. First, PGSC elastomers are obtained after the thermal curing of the moldable mixtures consisting of citric acid

Quanyong Liu; Tianwei Tan; Jingyi Weng; Liqun Zhang

2009-01-01

333

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

334

Study of erosion resistance and mechanical properties of unsaturated polyester based nano-composites  

Microsoft Academic Search

The addition of spherical and platelet shaped nano-particles in polymer composites has been shown to increase the electrical erosion resistance of insulation systems. Previous studies have mainly focused on the performance of epoxy based nano-composites and there are currently no studies evaluating the performance of ambient cured unsaturated polyester (UPR) nano-composites for their electrical erosion resistance. The present study focuses

Kanchan Nehete; Ram A. Sharma; Lokesh Chaudhari; Subhendu Bhattacharya; Vivek Singal; Dawid D'Melo

2012-01-01

335

Synthesis, Characterization and Glass Reinforcement of Poly(Ester Amido Imide)s  

Microsoft Academic Search

Poly(ester amido imide)s (PEAI)s (IIIa–e) were prepared by the intermolecular Diels-Alder (DA) reaction of bismaleimide (II) having epoxy resin segment with various bisfurans (Ia–e) having amide bridge. The DA reaction was carried out with tetrahydrofuran as a solvent, as well as in bulk, followed by aromatization of DA polyadduct intermediates in the presence of acetic anhydride. All the resultant polymers,

H. S. Patel; B. P. Patel; D. B. Patel

2009-01-01

336

Bio-based unsaturated polyester\\/layered silicate nanocomposites: Characterization and thermo-physical properties  

Microsoft Academic Search

Proper stiffness–toughness balance along with enhancement in other thermo-physical properties can be obtained by incorporating layered silicates (nanoclay) in bio-based resins, defined as blends of functionalized vegetable oils and petroleum-based resins. Bio-based polymer nanocomposites with varying clay concentration and varying bio-resin (epoxidized soy bean oil) content in unsaturated polyester resins were manufactured. Thermo-physical properties such as tensile modulus and strength,

Mahmoodul Haq; Rigoberto Burgueño; Amar K. Mohanty; Manjusri Misra

2009-01-01

337

Processing techniques for bio-based unsaturated-polyester\\/clay nanocomposites: Tensile properties, efficiency, and limits  

Microsoft Academic Search

Bio-based clay\\/polymer nanocomposites using blends of styrene-based unsaturated polyester and epoxidized methyl soyate were manufactured using solvent-based processing techniques. Four methods were evaluated to assess limitations related to solvent removal and incorporation of high clay and bio-resin content. Nanocomposite characterization was performed using electron microscopy and tensile tests. Solvent type, bio-resin addition sequence, and sonication energy were the key parameters

Mahmoodul Haq; Rigoberto Burgueño; Amar K. Mohanty; Manjusri Misra

2009-01-01

338

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

Microsoft Academic Search

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

M Messori; M Toselli; F Pilati; C Tonelli

2001-01-01

339

Fatigue strength of glass reinforced polyester (GRP) laminates with embedded optical fibers  

NASA Astrophysics Data System (ADS)

The effect of embedded optical fibers on the static and fatigue interlaminar shear strength of a glass reinforced polyester laminate is evaluated. Seventy identical specimens with and without embedded optical fibers were tested researching more than 500,000 cycles in some cases. It was found that the optical fiber does not have a negative influence on the laminate, neither static nor in fatigue. These tests were included into a project to develop smart wind turbine blades.

Guemes, Alfredo; Menendez, Jose M.

1996-04-01

340

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

341

Predicting the Thermal Conductivity of AlSi\\/Polyester Abradable Coatings: Effects of the Numerical Method  

Microsoft Academic Search

The final target of this study is to achieve a better understanding of the behavior of thermally sprayed abradable seals such\\u000a as AlSi\\/polyester composites. These coatings are used as seals between the static and the rotating parts in aero-engines.\\u000a The machinability of the composite coatings during the friction of the blades depends on their mechanical and thermal effective\\u000a properties. In

Rodolphe Bolot; Jean-Louis Seichepine; Jiang Hao Qiao; Christian Coddet

2011-01-01

342

Characterisation of the curing temperature effects on polyester systems by angle-resolved XPS (ARXPS)  

Microsoft Academic Search

The influence of peak metal temperature (PMT) applied to crosslinkable industrial coil coatings has been investigated by angle-resolved XPS (ARXPS). Two series of coatings based on different reactive polyester resins (linear or branched) but the same hexa-methoxy-methyl melamine crosslinking agent were involved. The formulations also contained either a poly(acrylic) or a silicone-based flow agent additive respectively. The coatings were cured

Christian Perruchot; John F Watts; Chris Lowe; Graham Beamson

2003-01-01

343

Dendrimers and Hyperbranched Polyesters as Structure?Directing Agents in the Formation of Nanoporous Silica  

Microsoft Academic Search

Anionic dendritic macromolecules (hyperbranched polyesters and polyamidoamine (PAMAM) dendrimers) and amine?functionalized PAMAM dendrimers have been used as structure?directing agents in the synthesis of nanoporous silica structures. When utilizing carboxylates as structure?directing agents the incorporation of the negatively charged species into a SiO2 framework was achieved via a sol?gel synthesis route using a quaternized aminosilane as co?structure?directing agent to yield silica

S. Volden; W. R. Glomm; H. Magnusson; G. Øye; J. Sjöblom

2006-01-01

344

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

345

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

346

Hydroxyl and acid number prediction in polyester resins by near infrared spectroscopy and artificial neural networks  

Microsoft Academic Search

Back-propagation artificial neural networks (BP-ANN) are applied for modeling hydroxyl number and acid value of a set of 62 samples of polyester resins from their near infrared (NIR) spectra. The results are compared to the classical calibration approaches, i.e. principal component regression (PCR) and partial least squares (PLS). The set of available samples is split into: (i) a training set,

Emilio Marengo; Marco Bobba; Elisa Robotti; Marcello Lenti

2004-01-01

347

Effects of CFC and HFC refrigerants and ester lubricants on polyester insulation materials  

Microsoft Academic Search

Three polyester motor insulation films-“standard” poly ethylene terephthlate (PET), “low oligomer” PET, and poly ethylene naphthalate (PEN)-have been examined for compatibility with a range of ozone benign HFC refrigerants and mixed acid polyolester lubricants. The results indicate that the R134a\\/ester lubricant mixture is considerably more aggressive in terms of oligomer extraction than CFC 12\\/mineral oil standard refrigerant\\/lubricant mixtures. However, low

D. W. Anderson; M. Handa

1995-01-01

348

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

Microsoft Academic Search

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

Rishikesh K. Bharadwaj; Richard H. Boyd

1999-01-01

349

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

Microsoft Academic Search

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

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

1997-01-01

350

Cure Monitoring of an Unsaturated Polyester Resin Using Near-Infrared and Fluorescence Spectroscopies  

Microsoft Academic Search

The applicability of both near-infrared (NIR) and fluorescence spectroscopy for the purpose of cure monitoring an unsaturated polyester (UPE) resin was investigated. Based on standard reference mixtures, peak assignments in the NIR region of the spectrum were made. It was determined that the peak at 1629 nm was due to the first overtone band of RHC=CH2 stretching modes in styrene,

Chong S. P. Sung; Bradley L. Grunden

1998-01-01

351

Polymerization conditions influence on the thermomechanical and dielectric properties of unsaturated polyester–styrene-copolymers  

Microsoft Academic Search

The influence of different polymerization conditions like curing agent (MEKP) amount and styrene content on the glass transition temperature, the relative dielectric constant as well as loss factors of unsaturated polyester–styrene-polymer systems after solidification was investigated in depth. With respect to a high average molecular mass and Vickers hardness a curing agent content of 3wt% is recommendable. Increasing MEKP-concentrations cause

T. Hanemann; B. Schumacher; J. Haußelt

2010-01-01

352

Microhardness of condensation polymers and copolymers. 2. Poly(ester ether carbonate) thermoplastic terpolymers  

Microsoft Academic Search

The number of phases, transition temperatures, and microhardness of a series of poly(ester ether carbonate) (PEEC) multiblock terpolymers with poly(butylene terephthalate) (PBT) hard segments have been investigated as a function of ether\\/carbonate (EC) soft-segment composition at constant PBT content. The polymerization degree of PBT and the intrinsic viscosity of the terpolymers were determined by viscosimetry. The degree of crystal-Unity, long

F. J. Baltá Calleja; S. Fakirov; Z. Roslaniec; M. Krumova; T. A. Ezquerra; D. R. Rueda

1998-01-01

353

Monotonic and fatigue behaviour of chopped-strand-mat\\/polyester composites with rigid and flexibilised matrix  

Microsoft Academic Search

Monotonic and tension–tension fatigue tests were carried out on E-glass chopped-strand-mat\\/polyester composites, varying the flexibiliser content by weight in the matrix in the range 0–30%. The flexibilising action was due to the adipic acid monomers present in the flexibiliser.In monotonic tests, the most marked effect of resin flexibility was in the transverse cracks formed during loading, whose critical density (i.e.,

G. Caprino; U. Prisco; L. Giorleo

2007-01-01

354

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

Microsoft Academic Search

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

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

2011-01-01

355

Enzymatic synthesis and curing of biodegradable epoxide-containing polyesters from renewable resources.  

PubMed

Epoxide-containing polyesters were enzymatically synthesized via two routes using unsaturated fatty acids as starting substrate. Lipase catalysis was used for both polycondensation and epoxidation of the unsaturated fatty acid group. One route was synthesis of aliphatic polyesters containing an unsaturated group in the side chain from divinyl sebacate, glycerol, and the unsaturated fatty acids, followed by an epoxidation of the unsaturated fatty acid moiety in the side chain of the resulting polymer. In another route, epoxidized fatty acids were prepared from the unsaturated fatty acids and hydrogen peroxide in the presence of lipase catalyst, and subsequently the epoxidized fatty acids were polymerized with divinyl sebacate and glycerol. The polymer structure was confirmed by NMR and IR, and for both routes, the high epoxidized ratio was achieved. Curing of the resulting polymers proceeded thermally, yielding transparent polymeric films with high gloss surface. Pencil scratch hardness of the present films improved, compared with that of the cured film obtained from the polyester having an unsaturated fatty acid in the side chain. The obtained film showed good biodegradability, evaluated by BOD measurement in an activated sludge. PMID:12625714

Uyama, Hiroshi; Kuwabara, Mai; Tsujimoto, Takashi; Kobayashi, Shiro

2003-01-01

356

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.

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

2010-01-01

357

Allergic alveolitis following exposure to epoxy polyester powder paint containing low amounts (<1%) of acid anhydrides.  

PubMed

Only one case report concerning allergic alveolitis caused by polyester powder paint has been published previously. The aim of this study was to determine whether phthalic anhydride (PA) or trimellitic anhydride (TMA) is the alveolitis-causing agent in such paint. A 61 year old woman showed recurrent symptoms of chills, cough, and fever whilst at work. She was working in a plant where epoxy polyester powder paints were used to paint metal. The paint was found to contain low (<1%) amounts of TMA and PA. The patient showed shadowing on chest radiographs. In bronchoalveolar lavage, lymphocytosis (67%) and a low T-helper/T-suppressor ratio (0.2) were found. Transfer factor was within normal limits, but a slight reduction was verified after re-exposure to the paint. The symptoms, exposure, reduction in transfer factor, findings on chest radiographs and bronchoalveolar lavage were consistent with allergic alveolitis. In conclusion, the polyester powder paint used in the plant caused allergic alve olitis in this patient. Of the constituents in the paint, trimellitic anhydride and phthalic anhydride were the possible causative agents. PMID:9150339

Piirilä, P; Keskinen, H; Anttila, S; Hyvönen, M; Pfäffli, P; Tuomi, T; Tupasela, O; Tuppurainen, M; Nordman, H

1997-04-01

358

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

359

Lipase catalyzed HEMA initiated ring-opening polymerization: in situ formation of mixed polyester methacrylates by transesterification.  

PubMed

2-Hydroxyethyl methacrylate (HEMA) was used as initiator for the enzymatic ring-opening polymerization (ROP) of omega-pentadecalactone (PDL) and epsilon-caprolactone (CL). The lipase B from Candida antarctica was found to catalyze the cleavage of the ester bond in the HEMA end group of the formed polyesters, resulting in two major transesterification processes, methacrylate transfer and polyester transfer. This resulted in a number of different polyester methacrylate structures, such as polymers without, with one, and with two methacrylate end groups. Furthermore, the 1,2-ethanediol moiety (from HEMA) was found in the polyester products as an integral part of HEMA, as an end group (with one hydroxyl group) and incorporated within the polyester (polyester chains acylated on both hydroxyl groups). After 72 h, as a result of the methacrylate transfer, 79% (48%) of the initial amount of the methacrylate moiety (from HEMA) was situated (acylated) on the end hydroxyl group of the PPDL (PCL) polyester. In order to prepare materials for polymer networks, fully dimethacrylated polymers were synthesized in a one-pot procedure by combining HEMA-initiated ROP with end-capping using vinyl methacrylate. The novel PPDL dimethacrylate (>95% incorporated methacrylate end groups) is currently in use for polymer network formation. Our results show that initiators with cleavable ester groups are of limited use to obtain well-defined monomethacrylated macromonomers due to the enzyme-based transesterification processes. On the other hand, when combined with end-capping, well-defined dimethacrylated polymers (PPDL, PCL) were prepared. PMID:18198845

Takwa, Mohamad; Xiao, Yan; Simpson, Neil; Malmström, Eva; Hult, Karl; Koning, Cor E; Heise, Andreas; Martinelle, Mats

2008-02-01

360

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

361

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

362

Effect of surface oxyfluorination on the bonding between acrylic coated optical fiber and cementitious and polyester resin matrices  

NASA Astrophysics Data System (ADS)

We examine the effect of fiber surface oxyfluorination on the interfacial bonding between acrylic coated optics fiber and a cementitious matrix and polyester resin respectively. The optical fiber is surface oxyfluorinated through a gas reaction process at room temperature in which elemental oxygen and fluorine are introduced into the acrylic molecular chain to replace the hydrogen atoms partially. After surface fluorination, the wettability of the optical fiber improves. Through an optical fiber embedment pull-out test, it is found that the surface oxyfluorination treatment improves on average the adhesional shear bond strength between the optical fiber and the cementitious matrix by 22% and the interfacial bonding between the optical fiber and the polyester resin matrix by 66%. The debonding of the unmodified optical fiber and the polyester matrix exhibits catastrophic failure characteristics, whereas that of the oxyfluorinated optical fiber with the polyester matrix is more gradual and there is still a substantial bond at the interface after the interfacial adhesive bond is broken. The mechanisms for the increase in interfacial bonding between the oxyfluorinated acrylic coated optical fiber and the cementitious and polyester resin matrices are proposed.

Swart, Pieter L.; Tu, Lin; Chtcherbakov, Anatoli A.

2000-04-01

363

Photocrosslinked poly(ester anhydride)s for peptide delivery: Effect of oligomer hydrophobicity on PYY3-36 delivery.  

PubMed

The treatment for many diseases can be improved by developing more efficient peptide delivery technologies, for example, biodegradable polymers. In this work, photocrosslinked poly(ester anhydride)s based on functionalized poly(?-caprolactone) oligomers were investigated for their abilities to achieve controlled peptide delivery. The effect of oligomer hydrophobicity on erosion and peptide release from poly(ester anhydride)s was evaluated by developing a sustained subcutaneous delivery system for an antiobesity drug candidate, peptide YY3-36 (PYY3-36). Oligomer hydrophobicity was modified with alkenylsuccinic anhydrides containing a 12-carbon alkenyl chain. PYY3-36 was mixed as a solid powder with methacrylated poly(ester anhydride) precursors, and this mixture was photocrosslinked at room temperature to form an implant for subcutaneous administration in rats. The oligomer hydrophobicity controlled the polymer erosion and PYY3-36 release as the increased hydrophobicity via the alkenyl chain prolonged polymer erosion in vitro and sustained in vivo release of PYY3-36. In addition, photocrosslinked poly(ester anhydride)s increased the bioavailability of PYY3-36 by up to 20-fold in comparison with subcutaneous administration of solution, evidence of remarkably improved delivery. In conclusion, this work demonstrates the suitability of photocrosslinked poly(ester anhydride)s for use in peptide delivery. PMID:21964317

Mönkäre, Juha; Hakala, Risto A; Kovalainen, Miia; Korhonen, Harri; Herzig, Karl-Heinz; Seppälä, Jukka V; Järvinen, Kristiina

2012-01-01

364

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

365

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

366

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

367

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.

Diaz, Angelica; Katsarava, Ramaz; Puiggali, Jordi

2014-01-01

368

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

369

Clickable Degradable Aliphatic Polyesters via Copolymerization with Alkyne Epoxy Esters: Synthesis and Postfunctionalization with Organic Dyes.  

PubMed

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

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

2014-07-23

370

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

371

Curing study of orthophtalic polyester resin: Effect on the degradation in saline environment  

NASA Astrophysics Data System (ADS)

Nowadays, composite materials based on a polymeric matrix are widely used in structural applications as engineering materials which offer high performances in advanced industrial sectors such as aerospace, aeronautical, transport, construction, etc. They can provide excellent mechanical and chemical properties, good chemical and weather resistance and low cost. Unsaturated polyester is one of the most used thermoset as a matrix for glass fibre reinforcements because of its good relationship properties/cost/quality, since it allows a more competitive cost. Due to the importance that this type of materials reach in some industrial sectors, it is important the mechanical behaviour evaluation as one of the priorities in practically any of their applications; also, it is important to keep in mind that most of industrial sectors that use this resin are subjected to extreme environmental conditions that can produce degradation in the material and therefore, chemical resistance of composites becomes a critical characteristic in those applications that require a contact with environmental agents that can induce some degradation processes and, consequently, a substantial change on general performance. The present study is focussed in the analysis of the effect of curing reaction of the thermosetting matrix of unsaturated orthophtalic polyester in the long term behaviour of materials made up of this type of matrix and glass fibre reinforcement. This is to determine the optimum processing conditions and its behaviour in an aggressive environment, concretely, marine environment. Considering this, crosslinking level of the resin is a decisive parameter, since we can expect lower saline water absorption for high crosslinking levels. The optimum processing conditions are those that permit to obtain the highest crosslinking level in the unsaturated polyester internal structure. Since the degradation effect is related to the crosslinking level of the internal structure, with the optimum cured state conditions the loss of mechanical performance due to degradation is minimum, and therefore the resin shows the maximum quality to reach specifications required in its industrial service.

Sanchez Nacher, Lourdes

372

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

373

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

374

High T(g) bio-based aliphatic polyesters from bicyclic D-mannitol.  

PubMed

The carbohydrate-based diol 2,4:3,5-di-O-methylene-d-mannitol (Manx) has been used to obtain aliphatic polyesters. Manx is a symmetric bicyclic compound consisting of two fused 1,3-dioxane rings and bearing two primary hydroxyl groups. In terms of stiffness, it is comparable to the widely known isosorbide, but it affords the additional advantages of being much more reactive in polycondensation and capable of producing stereoregular polymers with fairly high molecular weights. A fully bio-based homopolyester (PManxS) has been synthesized by polycondensation in the melt from dimethyl succinate and Manx. The high thermal stability of PManxS, its relatively high glass transition temperature (Tg = 68 °C) and elastic modulus, and its enhanced sensitivity to the action of lipases point to PManxS as a polyester of exceptional interest for those applications where biodegradability and molecular stiffness are priority requirements. In addition, random copolyesters (PBxManxyS) covering a broad range of compositions have been obtained using mixtures of Manx and 1,4-butanediol in the reaction with dimethyl succinate. All PBxManxyS were semicrystalline and displayed Tg values from -29 to +51 °C steadily increasing with the content in Manx units. The stress-strain behavior of these copolyesters largely depended on their content in Manx and they were enzymatically degraded faster than PBS. PMID:23363397

Lavilla, Cristina; Alla, Abdelilah; Martínez de Ilarduya, Antxon; Muñoz-Guerra, Sebastián

2013-03-11

375

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

376

Dry entrapment of enzymes by epoxy or polyester resins hardened on different solid supports.  

PubMed

Embedding of enzymes was performed with epoxy or polyester resin by mixing in a dried enzyme preparation before polymerization was started. This fast and low-cost immobilization method produced enzymatically active layers on different solid supports. As model enzymes the well-characterized Thermomyces lanuginosus lipase and a new threonine aldolase from Ashbya gossypii were used. It was shown that T. lanuginosus lipase recombinantly expressed in Aspergillus oryzae is a monomeric enzyme with a molecular mass of 34kDa, while A. gossypii threonine aldolase expressed in Escherichia coli is a pyridoxal-5'-phosphate binding homotetramer with a mass of 180kDa. The enzymes were used freeze dried, in four different preparations: freely diffusing, adsorbed on octyl sepharose, as well as cross-linked enzyme aggregates or as suspensions in organic solvent. They were mixed with standard two-component resins and prepared as layers on solid supports made of different materials e.g. metal, glass, polyester. Polymerization led to encapsulated enzyme preparations showing activities comparable to literature values. PMID:24835099

Barig, Susann; Funke, Andreas; Merseburg, Andrea; Schnitzlein, Klaus; Stahmann, K-Peter

2014-06-10

377

Determination of glyphosate and AMPA on polyester-toner electrophoresis microchip with contactless conductivity detection.  

PubMed

This paper reports a method for rapid, simple, direct, and reproducible determination of glyphosate and its major metabolite aminomethylphosphonic acid (AMPA). The platform described herein uses polyester-toner microchips incorporating capacitively coupled contactless conductivity detection and electrophoresis separation of the analytes. The polyester-toner microchip presented 150 ?m-wide and 12 ?m-deep microchannels, with injection and separation lengths of 10 and 40 mm long, respectively. The best results were obtained with 320 kHz frequency, 4.5 Vpp excitation voltage, 80 mmol/L CHES/Tris buffer at pH 8.8, injection in -1.0 kV for 7 s, and separation in -1.5 kV. RSD values related to the peak areas for glyphosate and AMPA were 1.5 and 3.3% and 10.1 and 8.6% for intra- and interchip assays, respectively. The detection limits were 45.1 and 70.5 ?mol/L, respectively, without any attempt of preconcentration of the analytes. Finally, the method was applied to river water samples in which glyphosate and AMPA (1.0 mmol/L each) were added. The recovery results were 87.4 and 83.7% for glyphosate and AMPA, respectively. The recovery percentages and LOD values obtained here were similar to others reported in the literature. PMID:23595638

da Silva, Eduardo R; Segato, Thiago P; Coltro, Wendell K T; Lima, Renato S; Carrilho, Emanuel; Mazo, Luiz H

2013-07-01

378

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

PubMed

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

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

2014-01-01

379

Hyperbranched polyester-based fluorescent probe for histone deacetylase via aggregation-induced emission.  

PubMed

Aberrant expression of histone deacetylases (HDACs) is related to various types of cancer and is associated with increased proliferation of tumor cells. Hence, the detection of HDAC activities is of great significance for medical sciences as well as biological diagnostics. Herein, we report a hyperbranched polyester-based one-step fluorescent assay for HDAC. This assay system consists of two water-soluble components: the hyperbranched polyester coupled with the acetylated lysine groups (H40-Lys(Ac)) and the negatively charged TPE derivative bearing two sulfonic acid groups (TPE-2SO3(-)). HDAC triggers the deacetylation of H40-Lys(Ac), thereby turning the electroneutral polymer into the positively charged one. Consequently, complexation occurs between the positively charged polymer and the negatively charged TPE-2SO3(-), thereby leading to the formation of nanoaggregates due to electrostatic interaction. Eventually, the fluorescence enhancement as a result of AIE effect is achieved. This assay system is operable in aqueous media with very low detection limit of 25 ng/mL. The system is capable of detecting HDAC in such biological fluid as serum, and this strategy may provide a new and effective approach for enzyme assay. PMID:24251690

Yu, Changmin; Wu, Yinglong; Zeng, Fang; Li, Xizhen; Shi, Jianbin; Wu, Shuizhu

2013-12-01

380

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

PubMed Central

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

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

2008-01-01

381

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.

2014-01-01

382

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

383

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".

384

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.

2014-05-01

385

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.

Network, Nanoscale I.; Sciencenter

2010-01-01

386

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...

387

Alternating copolymerization of dihydrocoumarin and epoxides catalyzed by chromium salen complexes: a new route to functional polyesters.  

PubMed

We report the alternating ring-opening copolymerization of dihydrocoumarin with epoxides catalyzed by chromium(iii) salen complexes. This process provides access to a range of perfectly alternating polyesters with high molecular weights and narrow molecular weight distributions. Atactic poly(cyclohexene dihydrocoumarate) and poly(cyclopentene dihydrocoumarate) were found to be semi-crystalline by differential scanning calorimetry. PMID:24806107

Van Zee, Nathan J; Coates, Geoffrey W

2014-05-20

388

Relationship between Dynamic Mechanical Properties and Water Absorption of Unsaturated Polyester and Vinyl Ester Glass Fiber Composites  

Microsoft Academic Search

The effect of hydrothermal degradation on polyester and vinyl ester mat glass fiber composites on viscoelastic properties is investigated by dynamic mechanical thermal analysis and flexural modulus. The adhesion between fiber and matrix is studied by short-beam shear test and by SEM microphotographs. Storage modulus in the glass state (Tg - 50 K) and rubber state (Tg + 50 K)

ALICIA N. FRAGA; VERA A. ALVAREZ; ANALIA VAZQUEZ; ORLANDO DE LA OSA

2003-01-01

389

Study on Stretching Methods of Biaxially Stretched Co-polyester Film with Has Uniaxially Heat Shrinkage Properties  

Microsoft Academic Search

Heat shrinkable film made of stretched film is widely used for decorative labels by attaching on PET bottles with heat shrinkage by steam or dry heating. Trouble cancellation in the installation process of the PET bottle is necessary. The purpose of this study is development of uniaxially heat shrinkable co-polyester film that has strength both in the machine direction (MD)

Masayuki Haruta; Yukinobu Mukouyama; Norimi Tabota; Katsuya Ito; Chisato Nonomura

2010-01-01

390

Photopolymerization of waterborne polyurethane acrylate dispersions based on hyperbranched aliphatic polyester and properties of the cured films  

Microsoft Academic Search

A series of novel waterborne hyperbranched polyurethane acrylates for aqueous dispersions (WHPUD) based on hydroxy-functionalized hyperbranched aliphatic polyester Boltorn™ H20 were investigated and used as UV curable oligomers. The aqueous dispersions were electrostatically stabilized with carboxyl groups incorporated into their structures, which were neutralized by triethylamine. The photopolymerization kinetics of these WHPUDs was studied with respect to polymerization rates and

Anila Asif; Cheng Yu Huang; Wen Fang Shi

2005-01-01

391

Structure–property study of waterborne, polyurethane acrylate dispersions based on hyperbranched aliphatic polyester for UV-curable coatings  

Microsoft Academic Search

A series of waterborne, hyperbranched polyurethane acrylates for aqueous dispersions (WHPUDs) based on hydroxy-functionalized hyperbranched aliphatic polyester Boltorn H20 were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR). The aqueous dispersions were electrostatically stabilized with carboxyl groups incorporated into their structures, which were neutralized by triethylamine (TEA). The effects of chemical structures of end groups on various properties of

Anila Asif; Chengyu Huang; Wenfang Shi

2004-01-01

392

Clinical experience of patellar fracture fixation using metal wire or non-absorbable polyester — a study of 37 cases  

Microsoft Academic Search

The results of patellar fracture fixation using metal wire and non-absorbable polyester (5 Ethibond) are presented. In group 1 (21 cases), the standard ‘AO’ technique using stainless steel wire was used, and in group 2 (16 cases) we used 5 Ethibond. Patients were assigned to the two groups on surgeon preference. Post-operative management in the two groups was similar, with

Harminder S. Gosal; Parminder Singh; Richard E. Field

2001-01-01

393

Permeability of N 2, Ar, He, O 2 and CO 2 through biaxially oriented polyester films — dependence on free volume  

Microsoft Academic Search

Permeability, diffusion and solubility coefficients are reported for biaxially orientated polyester films based on poly(ethylene terephthalate) [PET], poly(ethylene naphthalate) [PEN] and copolymers containing PET and PEN moieties. Data for cast amorphous sheets and materials produced with different biaxial draw ratios are compared. The crystallinity of the samples was assessed using differential scanning calorimetry and density measurements. The changes in the

E.-A McGonigle; J. J Liggat; R. A Pethrick; S. D Jenkins; J. H Daly; D Hayward

2001-01-01

394

The effect of woven and non-woven fiber structure on mechanical properties polyester composite reinforced kenaf  

NASA Astrophysics Data System (ADS)

The effects of woven and non-woven kenaf fiber on mechanical properties of polyester composites were studied at different types of perform structures. Composite polyester reinforced kenaf fiber has been prepared via hand lay-up process by varying fiber forms into plain weave, twill and mats structure. The reinforcing efficiency of different fiber structure was compared with control of unreinforced polyester sample. It was found that the strength and stiffness of the composites are largely affected by fiber structure. A maximum value for tensile strength of composite was obtained for twill weave pattern of fiber structure while no significant different for plain weave and mat structure. The elastic modulus of composite has shown some improvement on plain and twill weave pattern. Meanwhile, lower value of modulus elasticity achieved by mats structure composite as well as control sample. The modulus of rupture and impact resistance were also analyzed. The improvement of modulus of rupture value can be seen on plain and twill weave pattern. However impact resistance doesn't show significant improvement in all types of structure except for mat fiber. The mechanical properties of kenaf fiber reinforced polyester composite found to be increased with woven and non-woven fiber structures in composite.

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

2012-06-01

395

Interactions between F-111 Fuselage Fuel Tank Sealants. Part I. Characterisation of Polyester Sealants and their Hydrolytic Degradation Products.  

National Technical Information Service (NTIS)

Interactions between polysulfides and the hydrolysis products of polyester sealants EC 5106 and EC 5146 within integral fuselage fuel tanks of F-111 aircraft lead to fuel leaks. To assist in determining the mechanisms involved in this process a study of t...

P. J. Hanhela D. B. Paul

1983-01-01

396

Interactions Between F-111 Fuselage Fuel Tank Sealants. Part 1: Characterisation of Polyester Sealants and Their Hydrolytic Degradation Products.  

National Technical Information Service (NTIS)

Interactions between polysulfides and the hydrolysis products of polyester sealants EC 5106 and EC 5146 within integral fuselage fuel tanks of F-111 aircraft lead to fuel leaks. To assist in determining the mechanisms involved in this process a study of t...

P. J. Hanhela D. B. Paul

1983-01-01

397

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

398

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

399

Curing of polyester powder coating modified with rutile nano-sized titanium dioxide studied by DSC and real-time FT-IR  

Microsoft Academic Search

Polyester powder coating modified with 2 mass% of rutile nano-sized titanium dioxide (nano-TiO2) was prepared by melt-blend extrusion method. The nano-TiO2 dispersion state in the powder coating matrix was analyzed by field emission scanning electron microscopy (FE-SEM), which\\u000a presented a well dispersion of modified nano-TiO2 in the polyester powder coating. The effect of nano-TiO2 on the curing of polyester powder

Qiwu Shi; Wanxia Huang; Yubo Zhang; Yang Zhang; Yuanjie Xu; Gang Guo

400

Biocompatibility and biodegradation of polyester and polyfumarate based-scaffolds for bone tissue engineering.  

PubMed

Biodegradable and biocompatible polymeric scaffolds have been recently introduced for tissue regeneration purpose. In the present study we aimed to develop polymeric-based scaffolds for bone regeneration. Two polyesters, poly-beta-propiolactone (PBPL), poly-epsilon-caprolactone (PCPL) and two polyfumarates, polydiisopropyl fumarate (PDIPF), polydicyclohexyl fumarate (PDCF) were chosen to prepare films which can support osteoblastic growth. Scanning electron microscopy and water contact angle were used to characterize the matrices. Biodegradation studies were performed both in PBS buffer and using an in vitro macrophage degradation assay. Mouse calvaria-derived MC3T3E1 cells and UMR106 rat osteosarcoma cell lines were used to perform biocompatibility and cytotoxicity studies. The polyesters, the most hydrophilic polymers studied, showed a rougher and more porous surfaces than the polyfumarates. Under acellular conditions, only PBPL was degraded by hydrolytic mechanisms. However, macrophages performed an active degradation of all polymeric films. Osteoblasts developed well-defined actin fibres without evidence of cytotoxicity when growing on the films. The number of UMR106 osteoblasts that adhered to the PBPL-based film was higher than that of the cells attached to the PECL and polyfumarates (PDIPF and PDCF) matrices. Both UMR106 and MC3T3E1 osteoblastic lines showed protein levels comparable to control conditions, demonstrating that they grew well on all surfaces. However, UMR106 cells showed a significant increase in proliferation on polyester-derived scaffolds (PBPL and PECL). The alkaline phosphatase activity of UMR106, an osteoblastic marker, was significantly higher than that of control plastic dishes. MC3T3E1 cells expressed similar levels of this differentiation marker in all polymeric matrices. We found similar collagen protein content after 48 h culture of UMR106 cells on all surfaces. However, important differences were evident in the MC3T3E1 line. In conclusion, the synthetic polymeric-based scaffold we have developed and studied supports adhesion, growth and differentiation of two osteoblastic cell lines, suggesting that they could be useful in bone tissue regeneration. PMID:18273918

Cortizo, M Susana; Molinuevo, M Silvina; Cortizo, Ana M

2008-01-01

401

Photocatalytic degradation of toluene vapour using fixed bed multichannel photoreactors equipped with TiO2-coated fabrics.  

PubMed

The feasibility of producing TiO2-coated fabric using nonwoven polyester as a photocatalyst support was examined through investigations on (i) changes in the fabric properties after coating with TiO2, (ii) the toluene removal capacity of a multichannel TiO2/fabric/UV reactor in removing the toluene vapour with and without O3 addition, and (iii) the photocatalytic effect of regenerated TiO2. The value and usefulness of a multichannel photoreactor as a main reactor or a supplementary device to improve the efficiency of VOC (volatile organic chemicals) removal in a photoreacting fabric filter, which was originally invented to simultaneously remove fine dust and VOCs, was manifested through investigations of the multichannel effect in the treatment of large volumes of air containing toluene as a sample VOC vapour. The parallel-flow photoreactor was manufactured by fixing TiO2-coated fabrics in parallel along the gas flow and installing UV sources for every channel. Photocatalytic degradation of toluene vapour was investigated with respect to various operational parameters such as reaction time, photocatalyst load, vapour load and number of channels. Toluene vapour was taken as a sample VOC because it is a non-biodegradable toxic organic substance, and the UV/TiO2 process was tested as an alternative process to biofiltration. As a result of this study, it was confirmed that nonwoven polyester can be used as a photocatalyst support, and the multichannel photoreactor, equipped with TiO2-coated fabrics, is a useful device that can economically and efficiently treat a larger vapour load by providing more channels with ozone addition and by arranging the reactor units in series. PMID:18844127

Park, O H; Na, H Y

2008-09-01

402

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.

Goerz, Oliver

2014-01-01

403

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

404

[IR studies on hydrogen bonding in hard segment domains of segmented polyester polyurethaneurea].  

PubMed

Hydrogen bonding in hard segment domains of segmented polyester polyurethaneurea (PUU) based on 4,4'-diphenylmethane diisocyanate (MDI), ethylene diamine (ED) and polybutylene adipate (PBA) (M.W.1,975 and M.W.1,228) was studied by means of IR spectroscopy. It was found that the double peak absorption of urea C=O groups occurred in the studied PUU with the increase of hard segment content. Two hydrogen bonding models of urea C=O groups in different hard segment sequence lengths of PUU were proposed. Three dimensional hydrogen bonding in hard segment domains can be formed by further bonding of the above planar hydrogen bondings. PMID:12947612

Guo, X; Wang, Z; Zhang, G; Zhao, G; Zhao, W

2001-04-01

405

Facile preparation of novel peptosomes through complex self-assembly of hyperbranched polyester and polypeptide.  

PubMed

This work reported for the first time a facile template-free method to prepare polypeptide-based vesicles (peptosomes) through one-step complex self-assembly of carboxyl-terminated hyperbranched polyester and cationic poly-l-lysine (PLL). The preparation of such peptosomes, named complex peptosomes (CPs) here, is very simple just by mixing two kinds of polymer aqueous solutions together. The CP size can be readily controlled from nanosize to microsize through the adjustment of polymer concentration. The resulting nanosized CPs show unexpected size stability independent of a broad solution pH range, long-term storage stability, and almost no cytotoxicity and have demonstrated great potential to be used as the carriers in drug delivery. PMID:19453116

Guo, Bo; Shi, Zengqian; Yao, Yuan; Zhou, Yongfeng; Yan, Deyue

2009-06-16

406

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

407

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

PubMed

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 amyloyticus. It could degrade poly(lactic acid), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(caprolactone) and poly(ethylene succinate) but not poly(hydroxybutylate-co-valerate). However, it could not utilize these plastics as sole carbon sources. Both protease and esterase activities, which may be involved in the degradation of plastic, were constitutively detected in the culture broth. PMID:12882301

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

2003-01-01

408

Mortality of a cohort in a polyamide-polyester factory in Lyon: a further follow up.  

PubMed Central

In 1981-2 a retrospective study was undertaken in a polyamide-polyester factory in Lyon, France, to evaluate the effect of exposure to phthalates, nickel catalysers, and other chemicals in the work environment. The present paper reports the results of the follow up of this cohort up to July 1986. A slightly increased risk of cancers, in particular of the lung (44 cases), marginally related to exposure category but not significantly related to duration of exposure was found. The excess of skin cancers noted previously has disappeared, whereas an excess of cases of bladder cancer (based on seven cases) may be noted, mainly among nylon workers. The cohort is still young, however, and a continued follow up is likely to yield important information about the potential hazards associated with the nylon and tergal polymer industry.

Hours, M; Cardis, E; Marciniak, A; Quelin, P; Fabry, J

1989-01-01

409

Organocatalytic ring-opening polymerization of morpholinones: new strategies to functionalized polyesters.  

PubMed

The oxidative lactonization of N-substituted diethanolamines with the Pd catalyst [LPd(OAc)]2(2+)[OTf(-)]2 generates N-substituted morpholin-2-ones. The organocatalytic ring-opening polymerization of N-acyl morpholin-2-ones occurs readily to generate functionalized poly(aminoesters) with N-acylated amines in the polyester backbone. The thermodynamics of the ring-opening polymerization depends sensitively on the hybridization of the nitrogen of the heterocyclic lactone. N-Acyl morpholin-2-ones polymerize readily to generate polymorpholinones, but the N-aryl or N-alkyl substituted morpholin-2-ones do not polymerize. Experimental and theoretical studies reveal that the thermodynamics of ring opening correlates to the degree of pyramidalization of the endocyclic N-atom. Deprotection of the poly(N-Boc-morpholin-2-one) yields a water-soluble, cationic polymorpholinone. PMID:24946200

Blake, Timothy R; Waymouth, Robert M

2014-07-01

410

Radiation curing of polyester resin modified with acrylic acid and its salts  

NASA Astrophysics Data System (ADS)

Polyester resin containing acrylic acid or its salts was cured with ? 60Co radiation. The course of curing was examined, the gel content and polymerization shrinkage were measured and also thermographic and IR absorption analyses were carried out. It was found that manganese, iron and copper acrylates inhibited the curing of resin while the remaining additives showed a slightly stimulating action. All the additives decreased the polymerization shrinkage by a factor of 2-3 and iron acrylate by as much as 8 times (up to 1%). They also increased the activation energy of the thermal decomposition of resin, and calcium, barium and copper acrylates increased the thermal stability of resin by 20 K. IR absorption spectra showed that acrylic acid and its salts reacted mainly with the monomeric component of the resin (styrene) whereas iron and copper acrylates first attacked the unsaturated bonds of the oligoester.

Szali?ska, H.; Pietrzak, M.; Janowska, G.

411

Thermal Performance Measurements of a 100 Percent Polyester MLI (Multilayer Insulation) System for the Superconducting Super Collider: Part 1, Instrumentation and Experimental Preparation (300K-80K).  

National Technical Information Service (NTIS)

Thermal performance measurements of a 100 percent polyester multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) were conducted in a Heat Leak Test Facility (HLTF) under three experimental test arrangements. Each experiment meas...

W. N. Boroski J. D. Gonczy R. C. Niemann

1989-01-01

412

Low Temperature Measurement of Thermal and Mechanical Properties of Phenolic Laminate, the Pultruded Polyester Fiberglass and A and B Epoxy Putty.  

National Technical Information Service (NTIS)

Low temperature measurements were made and are reported of thermal and mechanical properties of phenolic laminate, pultruded polyester fiberglass, and A and B epoxy putty. To determine the modulus, compressive and tensile stress and strain, an Instron mac...

S. T. Wang S. H. Kim N. S. Kim R. S. Cheng J. Hoffman

1979-01-01

413

Interactions between F-111 Fuselage Fuel Tank Sealants. Part 2. Variation in Performance Properties of Polysulfides after Contact with Polyester Degradation Products.  

National Technical Information Service (NTIS)

Fuel leaks occur in F-111 aircraft from interactions between polysulfide sealants and the hydrolysis products of polyester sealants used to seal fuel cavities. Changes in properties of some polysulfides were examined following contact with degraded polyes...

D. B. Paul P. J. Hanhela

1984-01-01

414

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

PubMed

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

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

2013-12-01

415

Characterization of a resorbable poly(ester urethane) with biodegradable hard segments.  

PubMed

The rapid growth of regenerative medicine and drug delivery fields has generated a strong need for improved polymeric materials that degrade at a controlled rate into safe, non-cytotoxic by-products. Polyurethane thermoplastic elastomers offer several advantages over other polymeric materials including tunable mechanical properties, excellent fatigue strength, and versatile processing. The variable segmental chemistry in developing resorbable polyurethanes also enables fine control over the degradation profile as well as the mechanical properties. Linear aliphatic isocyanates are most commonly used in biodegradable polyurethane formulations; however, these aliphatic polyurethanes do not match the mechanical properties of their aromatic counterparts. In this study, a novel poly(ester urethane) (PEsU) synthesized with biodegradable aromatic isocyanates based on glycolic acid was characterized for potential use as a new resorbable material in medical devices. Infrared spectral analysis confirmed the aromatic and phase-separated nature of the PEsU. Uniaxial tensile testing displayed stress-strain behavior typical of a semi-crystalline polymer above its Tg, in agreement with calorimetric findings. PEsU outperformed aliphatic PCL-based polyurethanes likely due to the enhanced cohesion of the aromatic hard domains. Accelerated degradation of the PEsU using 0.1?M sodium hydroxide resulted in hydrolysis of the polyester soft segment on the surface, reduced molecular weight, surface cracking, and a 30% mass loss after four weeks. Calorimetric studies indicated a disruption of the soft segment crystallinity after incubation which corresponded with a drop in initial modulus of the PEsU. Finally, cytocompatibility testing with 3T3 mouse fibroblasts exhibited cell viability on PEsU films comparable to a commercial poly(ether urethane urea) after 24?h followed by 85% cell viability at 72?h. Overall, this new resorbable polyurethane shows strong potential for use in wide range of biomedical applications. PMID:24483140

Dempsey, David K; Robinson, Jennifer L; Iyer, Ananth V; Parakka, James P; Bezwada, Rao S; Cosgriff-Hernandez, Elizabeth M

2014-01-01

416

Fungal Communities Associated with the Biodegradation of Polyester Polyurethane Buried under Compost at Different Temperatures  

PubMed Central

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

Zafar, Urooj; Houlden, Ashley

2013-01-01

417

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

418

Friction and wear performance of some thermoplastic polymers and polymer composites against unsaturated polyester  

NASA Astrophysics Data System (ADS)

Wear experiments have been carried out with a range of unfilled and filled engineering thermoplastic polymers sliding against a 15% glass fibre reinforced unsaturated polyester polymer under 20, 40 and 60 N loads and 0.5 m/s sliding speed. Pin materials used in this experimental investigation are polyamide 66 (PA 66), poly-ether-ether-ketone (PEEK) and aliphatic polyketone (APK), glass fibre reinforced polyamide 46 (PA 46 + 30% GFR), glass fibre reinforced polytetrafluoroethylene (PTFE + 17% GFR), glass fibre reinforced poly-ether-ether-ketone (PEEK + 20% GFR), glass fibre reinforced poly-phylene-sulfide (PPS + 30% GFR), polytetrafluoroethylene filled polyamide 66 (PA 66 + 10% PTFE) and bronze filled pofytetrafluoroethylene (PTFE + 25% bronze) engineering polymers. The disc material is a 15% glass fibre reinforced unsaturated polyester thermoset polymer produced by Bulk Moulding Compound (BMC). Sliding wear tests were carried out on a pin-on-disc apparatus under 0.5 m/s sliding speed and load values of 20, 40 and 60 N. The results showed that the highest specific wear rate is for PPS + 30% GFR with a value of 1 × 10 -11 m 2/N and the lowest wear rate is for PTFE + 17% GFR with a value of 9.41 × 10 -15 m 2/N. For the materials and test conditions of this investigation, apart from polyamide 66 and PA 46 + 30% GFR polymers, the coefficient of friction and specific wear rates are not significantly affected by the change in load value. For polyamide 66 and PA 46 + 30% GFR polymers the coefficient of friction and specific wear rates vary linearly with the variation in load values.

Unal, H.; Mimaroglu, A.; Arda, T.

2006-09-01

419

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

PubMed Central

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

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

2011-01-01

420

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

421

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

PubMed

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

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

2011-12-12

422

A new tactic for Triatoma infestans control: fabrics impregnated with beta-cypermethrin.  

PubMed

Triatoma infestans is the most important vector of Chagas' disease in Argentina. Experiences from Argentine national campaigns have shown indoor spraying to control triatomine bugs is both expensive and difficult. An alternative control method may be the use of pyrethroid-impregnated fabrics (PIFs), which could be both a practical and cheap complement to conventional control measures. In this study, a formulation of emulsifiable concentrate of beta-cypermethrin [alpha-cyano-3-phenoxybenzyl-3-(2,2-dichlorovinyl)-2,2- dimethylcyclopropanecarboxilate] pyrethroid was used to impregnate different fabrics. The fabrics were then tested for their efficacy and persistence in killing Triatoma infestans. Insects attempting to penetrate or grasp the fabric in search of blood meals were poisoned by the exposure to the absorbed pyrethroid. Laboratory bioassays showed that the insecticidal effect of the PIFs with a dosage of 0.2 g/m2 lasted longer on wool than on cotton or rayon. Eight months after impregnation, a residual efficacy of 100% was found for wool, 80% for rayon-cotton fabrics, and 50% for rayon-polyester fabrics. In addition, beta-cypermethrin-impregnated fabrics showed a better repellency effect than did fabrics impregnated with either deltamethrin or cypermethrin. For field trials, fabrics were impregnated either in the laboratory or "in situ" at a dosage of 1 g beta-cypermethrin/m2 and then dried. The PIFs were placed inside homes, either under the roof or under the bed mattress. The field trials showed the PIF approach to be very effective in keeping dwellings free of triatomine bugs for at least one year and found a high degree of acceptability among the houses' residents. PMID:10446509

Wood, E; de Licastro, S A; Casabé, N; Picollo, M I; Alzogaray, R; Nicolás Zerba, E

1999-07-01

423

Fabrication of cell microintegrated blood vessel constructs through electrohydrodynamic atomization  

PubMed Central

Biodegradable synthetic matrices that resemble the size scale, architecture and mechanical properties of the native extracellular matrix can be fabricated through electrospinning. Tubular conduits may also be fabricated with properties appropriate for vascular tissue engineering. Achieving large cell infiltrate within the electrospun matrix in vitro remains time consuming and challenging. This difficulty was overcome by electrospraying smooth muscle cells concurrently with electrospinning of a biodegradable, elastomeric poly(ester urethane)urea (PEUU) small diameter conduit. Constructs were cultured statically or in spinner flasks. Hematoxylin and eosin (H&E) staining demonstrated qualitatively uniform SMC integration radially and circumferentially within the conduit after initial static culture. In comparison with static culture, samples cultured in spinner flasks indicated 2.4 times more viable cells present from MTT and significantly larger numbers of SMCs spread within the electrospun fiber networks by H&E image analysis. Conduits were strong and flexible with mechanical behaviors that mimicked those of native arteries, including static compliance of 1.6 ± 0.5 × 10?3 mmHg?1, dynamic compliance of 8.7 ± 1.8 × 10?4 mmHg?1, burst strengths of 1750 ± 220 mmHg, and suture retention. This method to rapidly and efficiently integrate cells into a strong, compliant biodegradable tubular matrix represents a significant achievement as a tissue engineering approach for blood vessel replacement.

Stankus, John J.; Soletti, Lorenzo; Fujimoto, Kazuro; Hong, Yi; Vorp, David A.; Wagner, William R.

2007-01-01

424

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.

2011-08-03

425

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

426

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

427

Preparation and evaluation of microspheres prepared from novel polyester-ibuprofen conjugates blended with non-conjugated ibuprofen.  

PubMed

A novel polyester, poly(glycerol-adipate-co-omega-pentadecalactone) (PGA-co-PL), was conjugated with a model drug, ibuprofen, through the free hydroxyl groups of the former and the free carboxyl group of the latter at various levels of substitution. The conjugated material was processed into microspheres by both emulsion solvent evaporation and spray-drying methods. Samples of conjugated material were also blended with non-conjugated drug and the microspheres produced were evaluated by various methods. Morphologically, the microspheres produced were satisfactory. However, there was some initial burst drug release from all samples, probably due to the presence of non-conjugated drug. Subsequent drug release was very slow due to the relative stability of the covalent bonding of the drug-polyester conjugate. Stability tests showed that storage at high relative humidity resulted in increased burst release. PMID:19888876

Thompson, C J; Hansford, D; Higgins, S; Rostron, C; Hutcheon, G A; Munday, D L

2009-12-01

428

Surface assisted laser desorption ionization-mass spectrometry (SALDI-MS) for analysis of polyester degradation products.  

PubMed

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. PMID:22392621

Aminlashgari, Nina; Hakkarainen, Minna

2012-06-01

429

Real-time WAXS study of induced orientation in a liquid crystalline polyester under the influence of a magnetic field  

Microsoft Academic Search

The in situ variation of induced orientation within a liquid crystalline polyester under the influence of a magnetic field was investigated during heat treatment, by means of wide-angle X-ray scattering (WAXS) using synchrotron radiation. The kinetics of molecular orientation, both from the melt and from the solid state, is analyzed in a wide temperature range (T=190–260°C) in terms of the

F Ania; A Flores; H. R Kricheldorf; F. J Baltá-Calleja

2003-01-01

430

Recombinant expression of BTA hydrolase in Streptomyces rimosus and catalytic analysis on polyesters by surface plasmon resonance.  

PubMed

A recombinant polyester-degrading hydrolase from Thermobifida sp. BCC23166 targeting on aliphatic-aromatic copolyester (rTfH) was produced in Streptomyces rimosus R7. rTfH was expressed by induction with thiostrepton as a C-terminal His(6) fusion from the native gene sequence under the control of tipA promoter and purified from the culture supernatant to high homogeneity by a single step affinity purification on Ni-Sepharose matrix. The enzyme worked optimally at 50-55 degrees C and showed esterase activity on C3-C16 p-nitrophenyl alkanoates with a specific activity of 76.5 U/mg on p-nitrophenyl palmitate. Study of rTfH catalysis on surface degradation of polyester films using surface plasmon resonance analysis revealed that the degradation rates were in the order of poly-epsilon-caprolactone > Ecoflex > polyhydroxybutyrate. Efficient hydrolysis of Ecoflex by rTfH was observed in mild alkaline conditions, with the highest activity at pH 8.0 and ionic strength at 250 mM sodium chloride, with the maximal specific activity of 0.79 mg(-1)min(-1)mg(-1) protein. Under the optimal conditions, rTfH showed a remarkable 110-time higher specific activity on Ecoflex in comparison to a lipase from Thermomyces lanuginosus, while less difference in degradation efficiency of the two enzymes was observed on the aliphatic polyesters, suggesting greater specificities of rTfH to the aliphatic-aromatic copolyester. This study demonstrated the use of streptomycetes as an alternative expression system for production of the multi-polyester-degrading enzyme of actinomycete origin and provided insights on its catalytic properties on surface degradation contributing to further biotechnological application of this enzyme. PMID:20174792

Sinsereekul, Nitat; Wangkam, Thidarat; Thamchaipenet, Arinthip; Srikhirin, Toemsak; Eurwilaichitr, Lily; Champreda, Verawat

2010-05-01

431

Effect of Phase Arrangement on Solid State Mechanical and Thermal Properties of Polyamide 6\\/Polylactide Based Co-polyester Blends  

Microsoft Academic Search

The main goal of this work is to correlate morphological parameters of the binary blend of polyamide 6 (PA6) and a polylactide based biodegradable co-polyester blend (BioFlex) (scanning electron microscopy, solvent extraction method) with the solid-state mechanical properties (stress strain analysis) as well as thermal (differential scanning calorimetry) and selected physico-chemical characteristics (Fourier transform infrared spectroscopy and water uptake analysis).

VLADIMIR SEDLARIK; ONON OTGONZUL; TAKESHI KITANO; ADRIANA GREGOROVA; MARTA HRABALOVA; ITA JUNKAR; UROS CVELBAR; MIRAN MOZETIC; PETR SAHA

2011-01-01

432

Effect of Phase Arrangement on Solid State Mechanical and Thermal Properties of Polyamide 6\\/Polylactide Based Co-polyester Blends  

Microsoft Academic Search

The main goal of this work is to correlate morphological parameters of the binary blend of polyamide 6 (PA6) and a polylactide (PLA) based biodegradable co-polyester blend (BioFlex) (scanning electron microscopy, solvent extraction method) with the solid-state mechanical properties (stress strain analysis) as well as thermal (differential scanning calorimetry) and selected physico-chemical characteristics (Fourier transform infrared spectroscopy and water uptake

Vladimir Sedlarik; Onon Otgonzul; Takeshi Kitano; Adriana Gregorova; Marta Hrabalova; Ita Junkar; Uros Cvelbar; Miran Mozetic; Petr Saha

2012-01-01

433

The Friction of Polyester Staple Fibres: The Effects of Speed, Processing, Spin Finish, Humidity, and Counterface-surface Roughness  

Microsoft Academic Search

Experiments are described in which a capstan method was used to measure the fibre\\/metal and fibre\\/fibre coefficients of friction of single polyester staple fibres. Tests were conducted on fibres carrying the manufacturer's spin finish, before and after partial processing into yarn, and on cleaned fibres. The cleaned fibres were tested against stainless-steel pins of roughness 0.08, 0.11, and 0.28 ?m

Margaret M. Robins; R. W. Rennell; R. D. Arnell

1988-01-01

434

Implementation of Taguchi Design for Erosion of Fiber-Reinforced Polyester Composite Systems with SiC Filler  

Microsoft Academic Search

With the increased use of fiber\\/filler-reinforced polymer composites in erosive work environments, it has become extremely important to investigate their erosion characteristics intensively. This article describes the development of a multi-component composite system consisting of thermoplastic polyester resin reinforced with E-glass fiber and SiC particles, and studies its erosion behavior under different operating conditions. A room temperature erosion test facility

AMAR PATNAIK; ALOK SATAPATHY; S. S. Mahapatra; R. R. Dash

2008-01-01

435

Novel Banded Structures in a Combined Main-Chain\\/Side-Chain Crystalline Polyester: from Liquid Crystals to Confined Crystals  

Microsoft Academic Search

Characterization of banded structures obtained from liquid crystals to confined crystallization has been investigated using optical and atomic force microscopy. A combined main-chain\\/side-chain liquid crystalline (LC) polyester, PEFBP(n = 11), was focused on to illustrate the formation of interesting additional bands on crystallization. On macroscopic scales, both approaches can be applied to visualize the morphological changes in these banded textures.

Jason J. Ge; Wensheng; Zhou; John Z. Zhang; Shy-Yeu Wang; Frank W. Harris; Stephen Z. D. Cheng

2000-01-01

436

Effect of acid groups in hydroxyl functional resins on the properties of polyester-urethane powder coatings  

Microsoft Academic Search

Hydroxyl-terminated polyester resins with different acid numbers were synthesized and used in powder coating formulations.\\u000a Coatings were formulated with isophorone diisocyanate (IPDI)-based hardeners and tested for mechanical performance, appearance,\\u000a and weathering. This study found that resins containing a high concentration of residual acid groups (also referred to as\\u000a undercondensed resins) had to be formulated according to their total reactive number,

Bin Wu; Sanjay Padaki; Daniel Maetens

2000-01-01

437

Mechanical and thermal studies of intercross-linked networks based on siliconized polyurethane-epoxy\\/unsaturated polyester coatings  

Microsoft Academic Search

Two different intercross-linked networks (ICN) of siliconized polyurethane-epoxy\\/unsaturated polyester (UP) coatings were developed. Epoxy and UP resins were modified with polyurethane (PU) prepolymer and hydroxyl terminated polydimethylsiloxane (HTPDMS) using ?-aminopropyl triethoxysilane (?-APS) and vinyltriethoxysilane (VTES) as silane cross-linkers and dibutyltindilaurate (DBTL) as catalyst. Aromatic polyamine adduct (A) and aliphatic amine (B) were used as curatives for epoxy and methyl isobutyl

A Anand Prabu; M Alagar

2004-01-01

438

Formulation and performance evaluation of hydroxyl terminated hyperbranched polyesters based poly (ester–urethane–urea) coatings on mild steel  

Microsoft Academic Search

A low molecular weight, anticorrosive hyperbranched poly (ester–urethane–urea) [HB-P(EUU)] coatings were formulated using 2nd generation hydroxyl terminated hyperbranched polyesters (OH–HBPEs), isophorone di-isocyanate (IPDI) as a cross linking agent and dibutyltin dilaurate (DBTDL) as a catalyst with certain additives. First, NCO terminated prepolymers (HBPEUs) were formulated by reacting OH–HBPEs with IPDI at NCO:OH ratio of 1.1:1 for 4h at 70–80°C, then

Rama Shanker Mishra; A. S. Khanna

2011-01-01

439

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

440

Effect of nanoclay on shrinkage control of low profile unsaturated polyester (UP) resin cured at room temperature  

Microsoft Academic Search

The addition of a small amount of nanoclay (1–3wt%) can provide excellent volume shrinkage control of unsaturated polyester (UP)\\/styrene (St)\\/poly(vinyl acetate) (PVAc) systems cured at room temperature. PVAc serves as the low profile additive (LPA). In this study, both temperature-induced phase separation of the uncured resin mixture and transmission electron microscopy (TEM) of the cured sample revealed that nanoclay resided

Liqun Xu; L. James Lee

2004-01-01

441

Network polymer electrolytes based on poly(ester diacrylate), ethylene carbonate, and LiClO 4  

Microsoft Academic Search

Network polymer electrolytes based on poly(ester diacrylate), LiClO4, and ethylene carbonate are synthesized and investigated via the methods of electrochemical impedance spectroscopy, DSC,\\u000a and thermal analysis. It is found that, for the polymer-LiClO4 system, the conductivity is 4.2 × 10?7 S\\/cm at 20°C. With a gradual increase in the amount of ethylene carbonate, the conductivity first decreases and then increases.

K. G. Khatmullina; O. V. Yarmolenko; L. M. Bogdanova

2010-01-01

442

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

443

Comparative degradation by micro-organisms of terephthalic acid, 2,6-naphthalene dicarboxylic acid, their esters and polyesters  

Microsoft Academic Search

Various derivatives of terephthalic acid (TA) and 2,6-naphthalene dicarboxylic acid (NDA) have been degraded in the presence of various strains of micro-organisms. These compounds include the dimethylesters (TME and NDME), the ethylene glycoldiesters (TGE and NDGE) and the corresponding ethylene glycol polyesters (PET and PEN). The terephthalic acid derivatives were shown not to be degraded by a pure strain of

C. Lefèvre; C. Mathieu; A. Tidjani; I. Dupret; C. Vander Wauven; W. De Winter; C. David

1999-01-01

444

Mechanical and Abrasive Wear Behavior of Coleus Spent Filled Unsaturated Polyester\\/Polymethyl Methacrylate Semi Interpenetrating Polymer Network Composites  

Microsoft Academic Search

Mechanical properties and three-body abrasive wear behavior of 5 and 10% w\\/w bio-based coleus spent (CS) filled and unfilled semi interpenetrating polymer network composites of unsaturated polyester\\/polymethyl methacrylate (80\\/20) have been studied. The tensile strength and elongation at break has been evaluated using 4302 Hounsfield Universal testing machine. The effect of abrading distances viz., 150, 300, 450, and 600 m

Murtuza Ali Syed; Siddaramaiah; B. Suresha; Akheel Ahmed Syed

2009-01-01

445

Influence of fibre orientation and stacking sequence on petalling of glass\\/polyester composite cylindrical shells under axial compression  

Microsoft Academic Search

The energy absorbing capability of FRP composite cylindrical tubes used as energy absorbers, by destroying itself progressively, depends on the way in which the tube material is crushed i.e., trend of petalling. This paper investigates the influence of fibre orientation and stacking sequence on the petal formation and specific energy absorption (SEA) of four and six-ply, 0°\\/90° glass\\/polyester composite cylindrical

S. Solaimurugan; R. Velmurugan

2007-01-01

446

A zirconia-polyester glycol coating on differently pretreated AISI 316L stainless steel: corrosion behavior in chloride solution  

Microsoft Academic Search

The effect of zirconia and zirconia-polyester glycol hybrid coatings on the corrosion resistance of mechanically polished\\u000a or anodized AISI 316 stainless steel (316L), was studied by potentiodynamic polarization and electrochemical impedance spectroscopy\\u000a in 0.1 M NaCl and scanning electron microscope and atomic force microscopy examinations. The deposition of zirconia coatings\\u000a was achieved by the sol–gel technique by immersing the samples in

C. Martinez; M. Sancy; J. H. Zagal; F. M. Rabagliati; B. Tribollet; H. Torres; J. Pavez; A. Monsalve; M. A. Paez

2009-01-01

447

Scale-up of polyamide and polyester Parsol® MCX nanocapsules by interfacial polycondensation and solvent diffusion method.  

PubMed

The scale-up of oil-containing polyamide nanocapsules produced by simultaneous interfacial polycondensation and solvent diffusion was successfully achieved. Up to 1,500 mL were produced by using a Y-shaped mixer device. The sizes of nanocapsules containing olive oil were modulated from 646 to 211 nm by changing process parameters without modification of the formulation composition. All the results of nanocapsule diameters (dsc) expressed as a function of the Reynolds number (Re) showed the existence of a typical power-law relationship. It was demonstrated that the high turbulences created upon nanocapsule formation are the most important parameter allowing to nanocapsule size to be controlled without modifying the formulation composition. Finally, the power-law relationship was used to predict the size of nanocapsules composed of polyamide or polyester and loaded with Parsol(®) MCX. The physico-chemical properties of both polyamide and polyester nanocapsules at the laboratory scale were compared to the ones obtained at the pilot scale. The encapsulation efficiency was higher than 98% in both types of nanocapsules at the laboratory and the pilot scales. The in vitro releases of Parsol(®) MCX from polyester nanocapsules were reproducible at both scales. This is the first time such a power-law was described for the preparation of nanocapsules by interfacial polycondensation and solvent diffusion. PMID:23834834

Stumpo, Marianna; Anselmi, Cecilia; Vauthier, Christine; Mitri, Khalil; Hanno, Ibrahim; Huang, Nicolas; Bouchemal, Kawthar

2013-10-01

448

Lipase-catalyzed synthesis of azido-functionalized aliphatic polyesters towards acid-degradable amphiphilic graft copolymers.  

PubMed

A series of novel aliphatic polyesters with azido functional groups were synthesized via the direct lipase-catalyzed polycondensation of dialkyl diester, diol and 2-azido-1,3-propanediol (azido glycerol) using immobilized lipase B from Candida antarctica (CALB). The effects of polymerization conditions including reaction time, temperature, enzyme amount, substrates and monomer feed ratio on the molecular weights of the products were studied. The polyesters with pendant azido groups were characterized by (1)H NMR, (13)C NMR, 2D NMR, FTIR, GPC and DSC. Alkyne end-functionalized poly(ethylene glycol) containing a cleavable acetal group was then grafted onto the polyester backbone by copper-catalyzed azide-alkyne cycloaddition (CuAAC, click chemistry). Using fluorescence spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM), these amphiphilic graft copolymers were found to readily self-assemble into nanosized micelles in aqueous solution with critical micelle concentrations between 0.70 and 1.97 mg L(-1), and micelle sizes from 20-70 nm. The degradation of these polymers under acidic conditions was investigated by GPC and (1)H NMR spectroscopy. Cell cytotoxicity tests indicated that the micelles had no apparent cytotoxicity to Bel-7402 cells, suggesting their potential as carriers for controlled drug delivery. PMID:24652240

Wu, Wan-Xia; Wang, Na; Liu, Bei-Yu; Deng, Qing-Feng; Yu, Xiao-Qi

2014-02-28

449

Clinical experience of patellar fracture fixation using metal wire or non-absorbable polyester--a study of 37 cases.  

PubMed

The results of patellar fracture fixation using metal wire and non-absorbable polyester (5 Ethibond) are presented. In group 1 (21 cases), the standard "AO" technique using stainless steel wire was used, and in group 2 (16 cases) we used 5 Ethibond. Patients were assigned to the two groups on surgeon preference. Post-operative management in the two groups was similar, with patients being allowed to mobilise as comfort allowed, under the supervision of the physiotherapists. All patients were followed-up until union of the fractures or until further surgical intervention was carried out. At a mean of 2 years and 6 months (range 1-4 years), we reviewed the notes and X-rays of all 37 cases. In group 2 there were no cases of infection but there were three cases of post-operative infections in group 1. Re-operation rate was 6/21 (38%) in group 1 and 1/6 (6%) in group 2. Therefore, the relative risk of re-operation in the metal group is six times that in the non-absorbable polyester group. The risk of infection in the metal group is also higher. These have implication on patient morbidity associated with the operative treatment of patellar fractures. Non-absorbable polyester appears to compare favourably with the use of metallic wire to fix patellar fractures. PMID:11223044

Gosal, H S; Singh, P; Field, R E

2001-03-01

450

Lipase-catalyzed synthesis of aliphatic polyesters via copolymerization of lactone, dialkyl diester, and diol.  

PubMed

Candida antarctica lipase (CALB) has been successfully used as catalyst for copolymerization of dialkyl diester with diol and lactone to form aliphatic polyesters. The polymerization reactions were performed using a two stage process: first stage oligomerization under low vacuum followed by second stage polymerization under high vacuum. Use of the two-stage process is required to obtain products with high molecular weights at high yields for the following reasons: (i) the first stage reaction ensures that the monomer loss via evaporation is minimized to maintain 1:1 diester to diol stoichiometric ratio, and the monomers are converted to nonvolatile oligomers; (ii) use of high vacuum during the second stage accelerates equilibrium transesterification reactions to transform the oligomers to high molecular weight polymers. Thus, terpolymers of omega-pentadecalactone (PDL), diethyl succinate (DES), and 1,4-butanediol (BD) with a M w of whole product (nonfractionated) up to 77000 and M w/ M n between 1.7 and 4.0 were synthesized in high yields (e.g., 95% isolated yield). A desirable reaction temperature for the copolymerizations was found to be around 95 degrees C. At 1:1:1 PDL/DES/BD monomer molar ratio, the resultant terpolymers contained equal moles of PDL, succinate, and butylene repeat units in the polymer chains. (1)H and (13)C NMR analyses were used to determine the polyester microstructures. The synthesized PDL-DES-BD terpolymers possessed near random structures with all possible combinations of PDL, succinate, and butylene units via ester linkages in the polymer backbone. Furthermore, thermal stability and crystallinity of a pure PDL-DES-BD terpolymer with 1:1:1 PDL to succinate to butylene unit ratio and M w of 85400 were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The copolyester was found to be a semicrystalline material with a T g of -34 degrees C and a T m of 64 degrees C, which degrades in a single weight loss step centered at T max = 408 degrees C. PMID:18939863

Jiang, Zhaozhong

2008-11-01

451

Development of conductive coated polyester film as RPC electrodes using screen printing  

NASA Astrophysics Data System (ADS)

Each of the three 16 kton ICAL detector modules at the India-based Neutrino Observatory (INO) will use RPCs as the active element, sandwiched between 6 cm thick soft iron plates, for measurements on atmospheric neutrinos. The electrodes of the RPC are float glass sheets having a volume resistivity of about 10 12-10 13 ? cm (at room temperature) covered with carbon/graphite or a conductive paint with a surface resistivity of ˜800 k?/square to 1 M?/square to apply high voltage on the glass surface, so that this surface does not shield the discharge signal from the external pickup plates and is small compared to the resistivity of the glass to provide a uniform potential across the entire surface. We initially coated the surface with locally available graphite powder, mixed with lacquer and thinner, and were able to get a few hundred k?/square resistivity. However, we observed a drastic reduction in surface resistivity with time and it came unstuck from the glass. Subsequently a conductive paint developed by Kansai-Nerolac was used. This paint uses modified acrylic resin as binder, conductive black pigment and solvents, which include aromatic hydrocarbons and alcohols. At room temperature, the surface dries in 10 minutes, while complete drying takes ˜18 hours. The spraying is done at a pressure of 4 kg/cm 2 with the glass plate kept at a distance of 8-10 in. Using this paint, we are able to achieve the required resistance of ˜ few hundred k?/square. We still need to study the long term stability and best curing method. We need to automate the procedure to get a uniform coat and to coat a large number of glasses for the final detector. While robotic systems are available abroad costing about 5 000 000 rupees, we are exploring other alternatives. In particular, we are in the process of developing a polyester film, with a conductive coating on one side, which can be glued on to the glass. The coating was done using on a local commercial screen printing machine (Grafica Flextronica, Vasai, India) using the screen printing ink viz. CARBO PASTE DC-1000M and DC-20 (Dozen Tech, Korea). A surface resistivity of a few hundred k?/square was obtained on a 100 mm thick polyester sheet of dimension 0.7 M×1.2 M. Curing was done for ˜30 minutes at 150 °C. We are planning to test this film on a glass RPC very soon.

Kalmani, S. D.; Mondal, N. K.; Satyanarayana, B.; Verma, P.; Datar, V. M.

2009-05-01

452

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

453

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

454

LIFE Target Fabrication Costs.  

National Technical Information Service (NTIS)

Target costs for the LIFE IFE plant comprises a significant portion of the operating costs for the commercial plant. A preliminary target fabrication and cost study was undertaken previously for a fast ignition target. An updated cost model is documented ...

G. Meyer J. Biener M. Wang R. Miles

2009-01-01

455

Heat Transfer Through Fabrics.  

National Technical Information Service (NTIS)

Heat is transferred through fabrics by convection, conduction and radiation and under certain circumstances by vaporization. Each mode is subject to different physical principles but the effect of the total heat absorbed by underlying skin is the same: if...

A. M. Stoll M. A. Chianta

1970-01-01

456

Prototype Space Fabrication Platform.  

National Technical Information Service (NTIS)

Current plans for constructing large structures in space entail fabricating the primary components, such as truss segments, on the ground and assembling them in space. This process requires an exorbitant number of support missions, and methods to minimize...

J. A. Bessel J. M. Ceney D. M. Crean E. A. Ingham D. J. Pabst

1993-01-01

457

Properties of Nonwoven Fabrics.  

National Technical Information Service (NTIS)

The paper is a report on the progress made in a study designed to establish the influence of several variables on the performance characteristics of nonwoven fabrics. Included among the variables are base fiber properties, binder fiber properties, web for...

S. C. Winchester J. C. Whitwell

1964-01-01

458

Speedo Fabric Testing  

NASA Video Gallery

Because the physical laws of motion for moving a body through water are the same as moving a vehicle through air, NASA aeronautics experts test the drag effects of different fabrics for Olympic-bou...

459

Other Fabric Structures  

NASA Technical Reports Server (NTRS)

Architects, engineers and building owners are turning increasingly to fabric structures because of their aesthetic appeal, relatively low initial cost, low maintenance outlays, energy efficiency and good space utilization. Several examples are shown.

1982-01-01

460

Fabricated torque shaft  

DOEpatents

A fabricated torque shaft is provided that features a bolt-together design to allow vane schedule revisions with minimal hardware cost. The bolt-together design further facilitates on-site vane schedule revisions with parts that are comparatively small. The fabricated torque shaft also accommodates stage schedules that are different one from another in non-linear inter-relationships as well as non-linear schedules for a particular stage of vanes.

Mashey, Thomas Charles (Anderson, SC)

2002-01-01

461

Chemical and electrochemical study of fabrics coated with reduced graphene oxide  

NASA Astrophysics Data System (ADS)

Polyester fabrics coated with reduced graphene oxide (RGO) have been obtained and later characterized by means of chemical and electrochemical techniques. X-ray photoelectron spectroscopy showed a decrease of the oxygen content as well as an increase of the sp2 fraction after chemical reduction of graphene oxide (GO). The electrical conductivity was measured by electrochemical impedance spectroscopy (EIS) and showed a decrease of 5 orders of magnitude in the resistance (?) when GO was reduced to RGO. The phase angle also changed from 90° for PES-GO (capacitative behavior) to 0° for RGO coated fabrics (resistive behavior). In general an increase in the number of RGO layers produced an increase of the conductivity of the fabrics. EIS measurements in metal/sample/electrolyte configuration showed better electrocatalytic properties and faster diffusion rate for RGO specimens. Scanning electrochemical microscopy was employed to test the electroactivity of the different fabrics obtained. The sample coated with GO was not conductive since negative feedback was obtained. When GO was reduced to RGO the sample behaved like a conducting material since positive feedback was obtained. Approach curves indicated that the redox mediator had influence on the electrochemical response. The Fe(CN)63-/4- redox mediator produced a higher electrochemical response than Ru(NH3)63+/2+ one.

Molina, J.; Fernández, J.; del Río, A. I.; Bonastre, J.; Cases, F.

2013-08-01

462

Mixture design applied for the study of the tartaric acid effect on starch/polyester films.  

PubMed

Tartaric acid (TA), a dicarboxylic acid, can act as a compatibiliser in starch/polyester blends. A mixture design was proposed to evaluate the effect of TA on the properties of starch/poly (butylene adipate co-terephthalate) (PBAT) blown films plasticised with glycerol. The interaction between the starch/PBAT and the TA has a positive effect on the tensile strength and puncture force. Additionally, greater proportions of TA increased Young's modulus. The starch+PBAT/TA and Gly/TA interactions contributed to a reduction in the water vapour permeability of the films. The inclusion of TA did not change the crystallinity of the samples. Formulations with intermediate proportions of TA (0.8 g/100 g) were shown to produce the best compatibilising effect. This was observed by DMA analysis as a consequence of the perfect equilibrium between the contributions of TA as a compatibiliser and in the acidolysis of starch, resulting in films with a tensile strength of 5.93 MPa, a possible alternative to non-biodegradable packaging. PMID:23399209

Olivato, J B; Nobrega, M M; Müller, C M O; Shirai, M A; Yamashita, F; Grossmann, M V E

2013-02-15

463

Predicting the Thermal Conductivity of AlSi/Polyester Abradable Coatings: Effects of the Numerical Method  

NASA Astrophysics Data System (ADS)

The final target of this study is to achieve a better understanding of the behavior of thermally sprayed abradable seals such as AlSi/polyester composites. These coatings are used as seals between the static and the rotating parts in aero-engines. The machinability of the composite coatings during the friction of the blades depends on their mechanical and thermal effective properties. In order to predict these properties from micrographs, numerical studies were performed with different software packages such as OOF developed by NIST and TS2C developed at the UTBM. In 2008, differences were reported concerning predictions of effective thermal conductivities obtained with the two codes. In this article, a particular attention was paid to the mathematical formulation of the problem. In particular, results obtained with a finite difference method using a cell-centered approach or a nodal formulation allow explaining the discrepancies previously noticed. A comparison of the predictions of the computed effective thermal conductivities is thus proposed. This study is part of the NEWAC project, funded by the European Commission within the 6th RTD Framework programm (FP6).

Bolot, Rodolphe; Seichepine, Jean-Louis; Qiao, Jiang Hao; Coddet, Christian

2011-01-01

464

Generation of conductivity through transfer charge properties, for polyesters and polyamides with characteristic functional groups  

NASA Astrophysics Data System (ADS)

Electro-optic properties of ?-conjugated polymers, as polysilylene; are associated with electron conjugation in the silicon atom, which allows a significant delocalization of electrons along of the chain. Thus, the conductivity is intimately connected to the mobility of charge carriers, which in turn depends on the structure and morphology of the system. We report the characterization of polyesters (PEFs) and polyamides (PAFs). Film thicknesses were obtained by ellipsometry. The vibration frequencies of the groups were determined by FT-IR and corroborated by Raman spectroscopy. Structural information was obtained from X-Ray diffraction (XRD). The structural and surface morphology were studied by scanning electron microscope (SEM). Electrical conductivity of the polymers was measured before and after exposure to iodine vapor, for films of different thicknesses. Morphological differentiation was studied by energy dispersive microscopy (EDX), showing a regular distribution of iodine within the polymer. Preliminary conductivity measurements showed adverse effects when oxidation of the polymer films is induced These effects are related to a certain grade of disorder within the system

Gonzalez, Carmen; Hernan Tagle, Luis; Terraza, Claudio A.; Barriga, Andres; Cabrera, A. L.; Volkmann, Ulrich G.

2011-03-01

465

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

466

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 microscop