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1

Tapered, tubular polyester fabric  

NASA Technical Reports Server (NTRS)

A tapered tubular polyester sleeve as set forth. It has a large end 12 and a small end 14 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 12. A requisite number of warp yarns 16 extend the full length of the sleeve. Other warp yarns exemplified at 18, 22, 26, 28, 30 and 32 extend from the large end but are terminated along the length of the sleeve. It is then woven with a filling yarn 40 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 42, heated in an oven 44 and is thereafter placed on the arm or other limb of a space suit exemplified at 50.

LaPointe, Donat J. E. (Inventor); Vincent, Laurence J. (Inventor); Wright, Lawrence T. (Inventor)

1988-01-01

2

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

3

Microwave heat dyeing of polyester fabric  

Microsoft Academic Search

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

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

2003-01-01

4

An alternative process for electroless copper plating on polyester fabric  

Microsoft Academic Search

Electroless copper plating of polyester fabrics was demonstrated in the present investigation. The electroless Cu plating\\u000a process on polyester fabric was modified by replacing the conventional PdCl2 activator with an AgNO3 activator to reduce the overall cost of the plating process. Both uncoated and Cu-coated polyester fabrics were characterized\\u000a by the scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), X-ray

R. H. Guo; S. Q. Jiang; C. W. M. Yuen; M. C. F. Ng

2009-01-01

5

Microwave assisted dyeing of polyester fabrics with disperse dyes.  

PubMed

Dyeing of polyester fabrics with thienobenzochromene disperse dyes under conventional and microwave heating conditions was studied in order to determine whether microwave heating could be used to enhance the dyeability of polyester fabrics. Fastness properties of the dyed samples were measured. All samples dyed with or without microwave heating displayed excellent washing and perspiration fastness. The biological activities of the synthesized dyes against Gram positive bacteria, Gram negative bacteria, yeast and fungus were also evaluated. PMID:24022764

Al-Mousawi, Saleh Mohammed; El-Apasery, Morsy Ahmed; Elnagdi, Mohamed Hilmy

2013-01-01

6

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

Microsoft Academic Search

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

Maged H. Zohdy

2005-01-01

7

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

E-print Network

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

Chiao, Jung-Chih

8

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

9

Improvements in the dyeability of polyester fabrics by atmospheric pressure oxygen plasma treatment  

Microsoft Academic Search

Polyester has been widely used as an apparel and technical textile material in the form of fibers, films and plastics due to its excellent mechanical and physical properties. However, its poor surface properties have limited its end?use versatility. In this study, the surface of a polyester fabric was modified by atmospheric pressure plasma treatment with oxygen under different operating conditions

M. M. Kamel; M. M. El Zawahry; H. Helmy; M. A. Eid

2011-01-01

10

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

11

Improvement of adhesion of conductive polypyrrole coating on wool and polyester fabrics using atmospheric plasma treatment  

Microsoft Academic Search

In this paper wool and polyester fabrics were pretreated with atmospheric plasma glow discharge (APGD) to improve the ability of the substrate to bond with anthraquinone-2-sulfonic acid doped conducting polypyrrole coating. A range of APGD gas mixtures and treatment times were investigated. APGD treated fabrics were tested for surface contact angle, wettability and surface energy change. Effect of the plasma

Saurabh Garg; Chris Hurren; Akif Kaynak

2007-01-01

12

Functionalization of polyester fabrics with alginates and TiO 2 nanoparticles  

Microsoft Academic Search

This study was aimed to investigate the possibility of engineering the multifunctional textile nanocomposite material based on the polyester fabric modified with natural polysaccharide alginate and colloidal TiO2 nanoparticles. The multifunctionality of such nanocomposite material was evaluated by analyzing its UV protection efficiency, antibacterial and photocatalytic activity. The level of UV protection was verified by the UV protection factor (UPF)

Darka Mihailovi?; Zoran Šaponji?; Marija Radoi?i?; Tamara Radeti?; Petar Jovan?i?; Jovan Nedeljkovi?; Maja Radeti?

2010-01-01

13

Use of an aliphatic hydrocarbon to improve adhesion in butyl rubber-proofed polyester fabric  

Microsoft Academic Search

An aliphatic hydrocarbon resin (Escoraze) was used as an additive in four bonding systems. These systems were based on (i) resorcinol, (ii) o-aminophenol, (iii) m-aminophenol, and (iv) m-phenylene diamine. Escoraze caused a significant additional adhesion force between the butyl rubber and the polyester fabric. The rubber-proofed fabric was subjected to an ionizing radiation. This led to better adhesion properties of

S. N. Lawandy; A. F. Younan; A. B. Shehata; N. A. Darwish; A. Mounir

1997-01-01

14

Laundry parameters as factors in lowering methyl parathion residue in cotton\\/polyester fabrics  

Microsoft Academic Search

Cotton\\/polyester fabrics were contaminated with a 1.25% solution of methyl parathion (MeP) emulsifiable concentrate formulation, then laboratory laundered. The laundering variables were detergent type, concentration, water volume, and mechanical agitation. Specimens were unfinished (UN) and soil repellent finished (SR) fabrics. Heavy duty liquid and phosphate-built powdered detergents were equally effective when used in combination with a prewash product. A negative

Debra N. Hild; Joan M. Laughlin; Roger E. Gold

1989-01-01

15

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

PubMed

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

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

2008-12-01

16

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

17

Microstructure and electromagnetic interference shielding effectiveness of electroless Ni–P plated polyester fabric  

Microsoft Academic Search

Microstructure and electromagnetic interference shielding effectiveness of electroless Ni–P deposits obtained from an alkaline\\u000a hypophosphite reducing electroless nickel bath was studied. The effects of plating temperature on the deposition rate, surface\\u000a morphology, chemical composition and structure of the electroless Ni–P deposits were investigated. Surface resistance and\\u000a electromagnetic interference (EMI) shielding effectiveness (SE) of Ni–P plated polyester fabric were also evaluated.

R. H. Guo; S. Q. Jiang; C. W. M. Yuen; M. C. F. Ng

2009-01-01

18

Electromagnetic shielding and corrosion resistance of electroless Ni–P\\/Cu–Ni multilayer plated polyester fabric  

Microsoft Academic Search

Nickel–phosphorus\\/copper–nickel (Ni–P\\/Cu–Ni) multilayers are electroless deposited onto polyester fabric as a function of the deposition time of Ni–P and compared with Ni–P and Cu–Ni deposits. Their surface morphology, microstructure and composition are analyzed by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray (EDX). Their electromagnetic interference (EMI) shielding effectiveness (SE) is evaluated and corrosion resistance is characterized

S. X. Jiang; R. H. Guo

2011-01-01

19

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

20

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

21

Laundry parameters as factors in lowering methyl parathion residue in cotton/polyester fabrics.  

PubMed

Cotton/polyester fabrics were contaminated with a 1.25% solution of methyl parathion (MeP) emulsifiable concentrate formulation, then laboratory laundered. The laundering variables were detergent type, concentration, water volume, and mechanical agitation. Specimens were unfinished (UN) and soil repellent finished (SR) fabrics. Heavy duty liquid and phosphate-built powdered detergents were equally effective when used in combination with a prewash product. A negative linear relationship between detergent concentration and MeP residue remaining after laundering was established. An interaction between detergent concentration and fabric finish was observed. Soil repellent finished fabrics required detergent concentrations above the recommended amount for more efficient soil removal. A negative linear relationship between water volume and after-laundering residue was observed. Water volume played a more significant role in pesticide removal than agitation during laundering. PMID:2619330

Hild, D N; Laughlin, J M; Gold, R E

1989-11-01

22

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

23

The dimensional and mechanical properties of wool\\/polyester fabrics made from vortex and ring-spun yarns  

Microsoft Academic Search

Fabric woven from wool\\/polyester (PES) Murata vortex spun (MVS) blend yarn is a commercially viable proposition particularly on the basis of advantageous wear-resistant properties, compared with fabric made from traditional worsted ring-spun yarn. However, in some early industrial trials with fabric made from 45\\/55-blend wool\\/PES MVS yarn, significantly greater relaxation shrinkage was found relative to comparable worsted ring-spun fabric. It

Q. Li; P. R. Brady; C. J. Hurren; X. G. Wang

2008-01-01

24

Comparison of the Mechanical Behavior of Plain Weave and Plain Weft Knit Jute Fabric-Polyester-Reinforced Composites  

Microsoft Academic Search

The tensile and impact behavior of jute fabrics—polyester composites–were evaluated as a function of the fabric style (knitted or weaved cloths), fiber weight fraction, and direction of the applied load. The tensile properties of plain-weave-fabric-reinforced composites (PWF) were higher than those of plain weft knit cloth composites (WKT) and were dependent on fiber content and test direction. The properties of

L. H. de Carvalho; J. M. F. Cavalcante; J. R. M. dAlmeida

2006-01-01

25

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. 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

26

THE CONSTRUCTION AND FINISHING OF FABRICS BASED ON TERYLENE POLYESTER FIBRE IN RELATION TO CREASE-RECOVERY  

Microsoft Academic Search

A study is made of some aspects of the relative crease-recovery of fabrics containing Terylene polyester fibre, wool, and blends of the two fibres. It is shown that wool is primarily affected in its crease-recovery by the presence of moisture, whilst Terylene fibre is subject to non-recoverable deformation imposed at high temperatures. The influence of structural and finishing variables on

G. LOASBY; N. M. Mims; E. D. Rossiter

1956-01-01

27

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

28

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

PubMed

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

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

2014-11-26

29

Manufacture technique and electrical properties evaluation of bamboo charcoal polyester\\/stainless steel complex yarn and knitted fabrics  

Microsoft Academic Search

There are derivative problems of electromagnetic wave radiation accompanying the advances of science and technology nowadays\\u000a and secure protections are also emphasized gradually. To shield these electromagnetic wave radition jeopardizing people’s\\u000a health, in this study, stainless steel wires were the core yarn and bamboo charcoal polyester textured yarns were the wrapped\\u000a yarn. The bamboo charcoal polyester\\/stainless steel (BC\\/SS) complex yarns

Jia-Horng Lin; An-Pang Chen; Chin-Mei Lin; Ching-Wen Lin; Chien-Teng Hsieh; Ching-Wen Lou

2010-01-01

30

DDT and methyl parathion residues found in cotton and cotton-polyester fabrics worn in cotton fields  

Microsoft Academic Search

Frequent spraying of cotton fields with chemicals to control insect pests is generally practiced in the Mississippi Delta area. The clothing worn by agricultural workers is subjected to direct contact with insecticide residues present in the field environment. The fiber content and special finishes in the fabrics worn by these workers may affect the pick=up, retention, and\\/or release of insecticide

E. L. Finley; J. R. B. Rogillio

1969-01-01

31

Neuraminidase produces a decrease of adherence of slime-forming Staphylococcus aureus to gelatin-impregnated polyester fiber graft fabric: an experimental study.  

PubMed

Because slime-forming microorganisms are the major causative agents of graft infections, we aimed to investigate bacterial adherence in slime-forming and nonslime-forming Staphylococcus aureus and to determine the role of neuraminidase (NANase) on adherence to gelatin-impregnated polyester fiber graft fabric. An in vitro model was developed to quantitatively measure bacterial adherence to the surface of the graft. The grafts were divided into two groups - those colonized with slime-forming S. aureus and those colonized with nonslime-forming S. aureus. The grafts were put into sterile tubes and human plasma was instilled and incubated at 37 degrees C to perform fibrin deposition on the grafts. After 48 h of incubation, grafts were drained and inoculated with slime-forming or nonslime-forming S. aureus in triptic soy broth in the presence or absence of NANase. Following 36 h of incubation at 36 degrees C, grafts were vortexed and cultured to perform a colony count. Bacterial counts were expressed as total colony-forming units per square centimeter of graft. Slime-forming S. aureus had greater affinity with the graft compared with nonslime-forming S. aureus (P < 0.05). The adherence of slime-forming S. aureus was impaired by NANase treatment (P < 0.001) but NANase treatment of nonslime-forming S. aureus did not change the adherence to the graft (P > 0.05). These results show that slime plays an important role in the pathogenesis of vascular graft infection. Adherence of slime-forming S. aureus can be decreased by NANase treatment. This may have implications for the development of neuraminidase-embedded vascular grafts to diminish biomaterial-related infections. PMID:17846717

Sacar, Mustafa; Onem, Gokhan; Baltalarli, Ahmet; Sacar, Suzan; Turgut, Huseyin; Goksin, Ibrahim; Ozcan, Vefa; Sakarya, Serhan

2007-01-01

32

Evaluating antistatic performance of plasma-treated polyester  

Microsoft Academic Search

Use of low temperature plasma treatment has been attempted in the textile industry and there the has been some success in\\u000a the dyeing and finishing processes. In this paper, an attempt was made to apply low temperature plasma treatment to improve\\u000a the antistatic property of polyester fabric. The polyester fabrics were treated under different conditions with low temperature\\u000a plasma. An

C. W. Kan

2007-01-01

33

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

34

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

35

Polyester Resin Hazards  

PubMed Central

Polyester resins are being increasingly used in industry. These resins require the addition of catalysts and accelerators. The handling of polyester resin system materials may give rise to skin irritations, allergic reactions, and burns. The burns are probably due to styrene and organic peroxides. Atmospheric pollution from styrene and explosion and fire risks from organic peroxides must be prevented. Where dimethylaniline is used scrupulous cleanliness and no-touch technique must be enforced. Handling precautions are suggested. Images PMID:14014495

Bourne, L. B.; Milner, F. J. M.

1963-01-01

36

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

37

Development of polyester and polyamide conductive fibre  

Microsoft Academic Search

Conducting polyester PET and polyamide PA-6 fibre and fabrics were prepared by in-situ chemical oxidative polymerisation using super critical fluid assisted process. The fibre materials and cloths produced were characterized by means of FTIR, WAXD, SEM, and DSC and two-probe resistivity. The samples were studied also by means of washing them several times. Homogeneous treated fibre materials with sustainable properties

Ali Harlin; Pertti Nousiainen; Arja Puolakka; Jani Pelto; Juha Sarlin

2005-01-01

38

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

39

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

40

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

41

4—THERMAL DEGRADATION OF FABRICS AND YARNS PART I: FABRICS  

Microsoft Academic Search

An investigation is reported in which fabrics were exposed to elevated temperatures for different times and the changes in dimensional stability, tear-resistance, breaking strength, and colour were determined. For tear-resistance and breaking strength, polyester-fibre fabrics were less affected by heat than the other fabrics tested. The polyester-fibre fabrics also retained their white appearance after all heat treatments, whereas all the

H. R. Richards

1984-01-01

42

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

43

Stabilized unsaturated polyesters  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

44

Liquid crystal polyester thermosets  

DOEpatents

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

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

1992-01-01

45

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

46

Polyester based hybrid organic coatings  

NASA Astrophysics Data System (ADS)

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

Wang, Xiaojiang

47

Review Degradation of microbial polyesters  

Microsoft Academic Search

Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(d-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of

Yutaka Tokiwa; Buenaventurada P. Calabia

2004-01-01

48

Fabric  

NSDL National Science Digital Library

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

N/A N/A (None;)

2004-07-12

49

Multifunctional aliphatic polyester nanofibers for tissue engineering.  

PubMed

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

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

2012-01-01

50

Ribosome-Catalyzed Polyester Formation  

Microsoft Academic Search

Deamination of phenylalanyl-transfer RNA with nitrous acid yields the alpha -hydroxyacyl analog, phenyllactyl-transfer RNA. When this is incubated in a protein-synthesizing system directed by polyuridylic acid, it yields an acid-precipitable, alkali-labile polyester of phenyllactic acid.

Stephen Fahnestock; Alexander Rich

1971-01-01

51

Synthesis of improved polyester resins  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

52

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

53

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

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Polyether polyester copolymer phosphate (generic). 721...Substances § 721.10213 Polyether polyester copolymer phosphate (generic). ...substance identified generically as polyether polyester copolymer phosphate (PMN...

2011-07-01

54

77 FR 60720 - Certain Polyester Staple Fiber From China  

Federal Register 2010, 2011, 2012, 2013

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

2012-10-04

55

75 FR 23300 - Greige Polyester/Cotton Printcloth From China  

Federal Register 2010, 2011, 2012, 2013

...731-TA-101 (Third Review)] Greige Polyester/Cotton Printcloth From China AGENCY...the antidumping duty order on greige polyester/cotton printcloth from China...the antidumping duty order on greige polyester/cotton printcloth from China...

2010-05-03

56

40 CFR 721.8082 - Polyester polyurethane acrylate.  

... 2014-07-01 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)...

2014-07-01

57

Synthesis of functionalized biodegradable polyesters.  

PubMed

This tutorial review summarizes recent developments in the syntheses of functionalized aliphatic polyesters. These polymers are attracting attention as sustainable alternatives to petrochemicals and for applications in medicine. Two main syntheses are described: step polymerization using mild chemo/enzymatic catalysis and ring opening polymerization, which is usually initiated by metal complexes. The methods are compared and their utility illustrated with reference to interesting new materials. PMID:17721582

Williams, Charlotte K

2007-10-01

58

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...

59

TEST OF FABRIC FILTRATION MATERIALS  

EPA Science Inventory

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

60

Longitudinal ruptures of polyester knitted vascular prostheses  

Microsoft Academic Search

Aim: The purpose of the study was the characterization of a type of rupture occurring on warp-knitted polyester vascular prostheses. Materials and Methods: We studied 20 cases of warp-knitted polyester vascular prostheses that were explanted from humans that showed a longitudinal rupture as a part of a collaborative retrieval program. All the prostheses were immediately fixed in a 10% formaldehyde

Nabil Chakfe; Gunnar Riepe; Florence Dieval; Jean-Francois Le Magnen; Lu Wang; Elisabeth Urban; Marc Beaufigeau; Bernard Durand; Herbert Imig; Jean-Georges Kretz

2001-01-01

61

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...

62

Electrospinning of novel biodegradable poly(ester urethane)s and poly(ester urethane urea)s for soft tissue-engineering applications  

Microsoft Academic Search

The development of biomimetic highly-porous scaffolds is essential for successful tissue engineering. Segmented poly(ester\\u000a urethane)s and poly(ester urethane urea)s have been infrequently used for the fabrication of electrospun nanofibrous tissues,\\u000a which is surprising because these polymers represent a very large variety of materials with tailored properties. This study\\u000a reports the preparation of new electrospun elastomeric polyurethane scaffolds. Two novel segmented

Pablo C. Caracciolo; Vinoy Thomas; Yogesh K. Vohra; Fabián Buffa; Gustavo A. Abraham

2009-01-01

63

Self-cleaning Polyurethane and Polyester Coatings.  

E-print Network

??Self-cleaning titanium dioxide (TiO2) based polyurethane and polyester nanocomposites were synthesized, characterized and tested in this thesis. A monomer functionalization method (“grafting from” polymerization) was… (more)

Tang, Yixing

2013-01-01

64

Sheeting fabric formed of corespun yarns  

US Patent & Trademark Office Database

A percale sheeting fabric of polyester and cellulosic fiber construction which more effectively utilizes the beneficial properties of the cellulosic fiber as compared to conventional polyester and cotton blend sheeting fabric constructions so as to provide a greatly increased moisture absorbency rate for enhanced comfort, and with enhanced cover, bulk and opacity. The fabric is formed of warp and filling yarns of corespun construction having a yarn count of about 34/1 to 37/1 cotton count, with the yarns being interwoven to form a woven fabric construction of at least about 180 threads per square inch. Each of the corespun warp and filling yarns has a core portion formed of multifilament polyester of a total denier of about 45 to 50, and a sheath portion formed of cellulosic fibers helically wrapped about the multifilament core portion to substantially surround and encase the same.

1980-03-04

65

Biodegradable microfluidic scaffolds for tissue engineering from amino alcohol-based poly(ester amide) elastomers.  

PubMed

Biodegradable polymers with high mechanical strength, flexibility and optical transparency, optimal degradation properties and biocompatibility are critical to the success of tissue engineered devices and drug delivery systems. Most biodegradable polymers suffer from a short half life due to rapid degradation upon implantation, exceedingly high stiffness, and limited ability to functionalize the surface with chemical moieties. This work describes the fabrication of microfluidic networks from poly(ester amide), poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate) (APS), a recently developed biodegradable elastomeric poly(ester amide). Microfluidic scaffolds constructed from APS exhibit a much lower Young's Modulus and a significantly longer degradation half-life than those of previously reported systems. The device is fabricated using a modified replica-molding technique, which is rapid, inexpensive, reproducible, and scalable, making the approach ideal for both rapid prototyping and manufacturing of tissue engineering scaffolds. PMID:21220957

Wang, Jane; Bettinger, Christopher J; Langer, Robert S; Borenstein, Jeffrey T

2010-01-01

66

75 FR 42784 - Greige Polyester/Cotton Printcloth From China  

Federal Register 2010, 2011, 2012, 2013

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

2010-07-22

67

Preparation methodology of radiation - curable resin. Unsaturated polyesters.  

National Technical Information Service (NTIS)

Two types of unsaturated polyester have been prepared according to normal alkyd methods of preparation. In this work the emphasis has been given to the preparation methodology of unsaturated polyesters in styrene. Their molecule weight distributions fall ...

Dahlan bin Haji Mohd Hussin bin Mohd Nor Mohamad Hilmi bin Mahmood

1989-01-01

68

The fracture toughness of bast fibre reinforced polyester composites Part 1 Evaluation and analysis  

Microsoft Academic Search

Hemp and jute fibre reinforced polyester composites were fabricated to various fibre volume fractions (Vf) up to 0.45. Laminates reinforced with a chopped strand mat (CSM) glass fibre were also manufactured. The tensile properties of these materials were evaluated. Fracture toughness was assessed, using linear elastic fracture mechanics (LEFM) principles, under quasi-static loading conditions. At equivalent Vf (0.2) it was

M. Hughes; C. A. S. Hill; J. R. B. Hague

2002-01-01

69

Microbial production of lactate-containing polyesters.  

PubMed

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

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

2013-11-01

70

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

PubMed

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

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

2014-11-01

71

49 CFR 173.165 - Polyester resin kits.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

72

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

73

40 CFR 721.6485 - Hydroxy terminated polyester.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

74

Mixed Polyether-Polyester Multiblock Copolymer and its Blood Compatibility  

Microsoft Academic Search

A new type of polyether-polyester block copolymer (MPEE) consisting of two components of polyethers (PTMGT and PEGT) as soft segment and one polyester (PET) as hard segment has been synthesized. It has also been investigated in comparison with blended polyether-polyester block copolymer (BPEE) consisting of the same composition ratio of hard and soft segments and both of the two polyethers

Shen-Guo Wang; Chuan-Fu Chen; Zhi-Fen Li; Xue-Fen Li; Han-Qing Gu

1989-01-01

75

Somatic Cell Cloning in Polyester Stacks  

Microsoft Academic Search

Single somatic cells, including fibroblasts, myelomas, and hybridomas, proliferate normally when trapped between a plastic dish and a disc of polyester cloth. Contact between the overlay and the plastic for 8-16 days results in identical colony patterns on the cloth and the plate. When several cloth discs are simultaneously stacked over Chinese hamster ovary cells, three or four high-resolution colony

Christian R. H. Raetz; Mary M. Wermuth; Thomas M. McIntyre; Jeffrey D. Esko; Debra C. Wing

1982-01-01

76

Antimicrobial wool, polyester and a wool/polyester blend created by silver particles embedded in a silica matrix.  

PubMed

A two-step antimicrobial finishing procedure was applied to wool (WO) and polyester (PES) fabrics and a WO/PES fabric blend, in which the pad-dry-cure method was performed to create a functional silica matrix through the application of an inorganic-organic hybrid sol-gel precursor (RB) followed by the in situ synthesis of AgCl particles on the RB-treated fibres using 0.10 and 0.50mM AgNO3 and NaCl. The bulk concentration of Ag on the cotton fibres was determined by inductively coupled plasma mass spectroscopy. The antimicrobial activity was determined for the bacteria Escherichia coli and Staphylococcus aureus, and the fungus Aspergillus niger. The results showed that the highest concentration of the adsorbed Ag compound particles was on the WO samples followed by the WO/PES and PES samples. The antimicrobial activity of the finished fabric samples strongly depended not only on the amount of adsorbed Ag but also on the properties of the fabric samples. Whereas Ag biocidal activity was generated for the finished PES samples at Ag particle concentrations of less than 10mg/kg, the 34-times higher Ag particle concentration on the WO samples was insufficient to impart satisfactory antimicrobial activity because Ag chemically binds to the thiol groups on wool. The presence of wool fibres in WO/PES samples decreased the antimicrobial protection of the fabric blend compared with that of the PES fabric. A lethal concentration of adsorbed Ag compound particles for bacteria and fungi was produced only through the treatment of the WO and WO/PES samples with 0.5mM AgNO3. PMID:23880089

Klemen?i?, Danijela; Tomši?, Brigita; Kova?, Franci; Žerjav, Metka; Simon?i?, Andrej; Simon?i?, Barbara

2013-11-01

77

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

Federal Register 2010, 2011, 2012, 2013

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

2012-02-09

78

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

Federal Register 2010, 2011, 2012, 2013

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

2012-04-02

79

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

Federal Register 2010, 2011, 2012, 2013

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

2013-08-21

80

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

81

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

Federal Register 2010, 2011, 2012, 2013

...Administration [A-580-839] Certain Polyester Staple Fiber from Korea: Rescission...June 30, 2010). Scope of the Order Polyester staple fiber (``PSF'') covered...otherwise processed for spinning, of polyesters measuring 3.3 decitex (3...

2010-08-09

82

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

Federal Register 2010, 2011, 2012, 2013

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic...the antidumping duty order on certain polyester staple fiber from the People's Republic...Chemical Fiber Corp. and Huvis Sichuan Polyester Fiber Ltd. (``Huvis...

2013-03-06

83

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

Federal Register 2010, 2011, 2012, 2013

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

2011-02-10

84

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

Code of Federal Regulations, 2011 CFR

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

2011-04-01

85

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

Federal Register 2010, 2011, 2012, 2013

...Duty Administrative Review of Certain Polyester Staple Fiber From the People's Republic...second administrative review of certain polyester staple fiber (``PSF'') from the...June 1, 2008-May 31, 2009. Certain Polyester Staple Fiber From the People's...

2010-10-20

86

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

...2014-04-01 false Partial phosphoric acid esters of polyester resins. 175.260...Coatings § 175.260 Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified...

2014-04-01

87

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

... false MDI terminated polyester polyurethane polymer (generic). 721.10298...10298 MDI terminated polyester polyurethane polymer (generic). (a) Chemical...generically as MDI terminated polyester polyurethane polymer (P-11-662) is...

2014-07-01

88

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

89

Biodegradation of microbial and synthetic polyesters by fungi  

Microsoft Academic Search

A variety of biodegradable polyesters have been developed in order to obtain useful biomaterials and to reduce the impact of environmental pollution caused by the large-scale accumulation of non-degradable waste plastics. Polyhydroxyalkanoates, poly(k-caprolactone), poly(l-lactide), and both aliphatic and aromatic polyalkylene dicarboxylic acids are examples of biodegradable polyesters. In general, most aliphatic polyesters are readily mineralized by a number of aerobic

D. Y. Kim; Y. H. Rhee

2003-01-01

90

Somatic cell cloning in polyester stacks.  

PubMed Central

Single somatic cells, including fibroblasts, myelomas, and hybridomas, proliferate normally when trapped between a plastic dish and a disc of polyester cloth. Contact between the overlay and the plastic for 8-16 days results in identical colony patterns on the cloth and the plate. When several cloth discs are simultaneously stacked over Chinese hamster ovary cells, three or four-high resolution colony copies can be generated from a single master dish. The colonies on the cloth can be analyzed by radiochemical methods [Esko, J. D. & Raetz, C. R. H. (1978) Proc. Natl. Acad. Sci. USA 75, 1190-1193] or by "replica plating" to a new disc. The use of polyester cloth, singly or in stacks, has several major advantages over previous techniques for somatic cell replica plating, including: (i) broad applicability to diverse cell lines such as fragile membrane mutants of Chinese hamster ovary cells and relatively nonadherent myelomas or hybridomas; (ii) the possibility of generating multiple copies of the same colony population, allowing simultaneous analysis for several enzymes or cellular components; and (iii) superior resolution and transfer efficiency in copying colony patterns from one surface to another. The remarkable capacity of animal cell colonies to proliferate upward through "polyester stacks" may reflect chemotropic movement of individual cells and opens new approaches to somatic cell genetics. Images PMID:6954474

Raetz, C R; Wermuth, M M; McIntyre, T M; Esko, J D; Wing, D C

1982-01-01

91

Dielectric investigation of some woven fabrics  

Microsoft Academic Search

In this paper, we have investigated the temperature dependence of dielectric properties (relative dielectric permeabilities and dielectric tangents of losses) for woven fabrics of hemp, jute, flax, cotton, polyester (PES), cotton-PES mixture, and wool. The measurements have been carried out at a temperature range from -50 to 50 °C in the electric periodic field at a frequency 1 MHz in

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

2009-01-01

92

Dielectric investigation of some woven fabrics  

Microsoft Academic Search

In this paper, we have investigated the temperature dependence of dielectric properties (relative dielectric permeabilities and dielectric tangents of losses) for woven fabrics of hemp, jute, flax, cotton, polyester (PES), cotton-PES mixture, and wool. The measurements have been carried out at a temperature range from ?50 to 50 °C in the electric periodic field at a frequency 1 MHz in

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

2009-01-01

93

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

94

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

95

Thermally Active Fabrics Containing Polyethylene Glycols  

Microsoft Academic Search

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

Joseph S. Bruno; Tyrone L. Vigo

1987-01-01

96

Influence of Household Fabric Softeners and Laundry Enzymes on Pilling and Breaking Strength  

Microsoft Academic Search

This study was undertaken to examine the un- resolved questions surrounding the influence of household fabric softeners and cellulase-en- zyme containing laundry detergents on pilling and strength of selected fabrics. Results showed that dryer sheet softeners were not associated with an increase in pilling, a greasy hand, nor increased breaking strength losses in any of the cotton or polyester fabrics

Patricia Cox Crews

2000-01-01

97

Polyester Based On Biodiesel Industry Residues  

NASA Astrophysics Data System (ADS)

Biodiesel production is growing exponentially offering the energy network an alternative fuel from renewable sources. However, large quantities of crude glycerol are generated as a bi-product (10-30%) wt during the transesterification process of biodiesel. Although glycerol in its purified form has a number of uses, crude glycerol obtained from the biodiesel industry contains many impurities and requires expensive purification processes resulting in vast amounts of glycerol without adequate destination which are causing rise to many environmental concerns. Large scale applications of glycerol are necessary to accompany its production. Polyesters obtained via the polycondensation of glycerol with aromatic acids were prepared in different ratios. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to investigate thermal stability. The composite structure was characterized by Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (DRX). These aromatic polyesters could offer a low cost environmentally compatible material for the production of components such as tiles, boards, sanitary vases and sinks for the construction industry.

Carvalho, Ricardo F.; Jose, Nadia M.; Carvalho, Adriana L. S.; Miranda, Cleidiene S.; Thomas, Natasha I. R.

2011-12-01

98

Diglycerol-based polyesters: melt polymerization with hydrophobic anhydrides.  

PubMed

The melt polymerization of diglycerol with bicyclic anhydride monomers derived from a naturally occurring monoterpene provides an avenue for polyesters with a high degree of sustainability. The hydrophobic anhydrides are synthesized at ambient temperature via a solvent-free Diels-Alder reaction of ?-phellandrene with maleic anhydride. Subsequent melt polymerizations with tetra-functional diglycerol are effective under a range of [diglycerol]/[anhydride] ratios. The hydrophobicity of ?-phellandrene directly impacts the swelling behavior of the resulting polyesters. The low E?factors (<2), large amount of bio-based content (>75?%), ambient temperature monomer synthesis, and polymer degradability represent key factors in the design of these sustainable polyesters. PMID:25138308

Dakshinamoorthy, Deivasagayam; Weinstock, Allison K; Damodaran, Krishnan; Iwig, David F; Mathers, Robert T

2014-10-01

99

Biodegradable microfluidic scaffolds for tissue engineering from amino alcohol-based poly(ester amide) elastomers  

PubMed Central

Biodegradable polymers with high mechanical strength, flexibility and optical transparency, optimal degradation properties and biocompatibility are critical to the success of tissue engineered devices and drug delivery systems. Most biodegradable polymers suffer from a short half-life due to rapid degradation upon implantation, exceedingly high stiffness, and limited ability to functionalize the surface with chemical moieties. This work describes the fabrication of microfluidic networks from poly(ester amide), poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate) (APS), a recently developed biodegradable elastomeric polymer. Microfluidic scaffolds constructed from APS exhibit a much lower Young's modulus and a significantly longer degradation half-life than those of previously reported systems. The device is fabricated using a modified replica-molding technique, which is rapid, inexpensive, reproducible and scalable, making the approach ideal for both rapid prototyping and manufacturing of tissue engineering scaffolds. PMID:21220957

Wang, Jane; Bettinger, Christopher J; Langer, Robert S

2010-01-01

100

Microbial degradation of polyurethane, polyester polyurethanes and polyether polyurethanes  

Microsoft Academic Search

Polyurethane (PUR) is a polymer derived from the condensation of polyisocyanate and polyol and it is widely used as a base\\u000a material in various industries. PUR, in particular, polyester PUR, is known to be vulnerable to microbial attack. Recently,\\u000a environmental pollution by plastic wastes has become a serious issue and polyester PUR had attracted attention because of\\u000a its biodegradability. There

T. Nakajima-Kambe; Y. Shigeno-Akutsu; N. Nomura; F. Onuma; T. Nakahara

1999-01-01

101

Polyester (Parietex) mesh for total extraperitoneal laparoscopic inguinal hernia repair  

Microsoft Academic Search

  Polypropylene mesh is the most commonly used mesh for open and laparoscopic hernia repair in the United States. A variety\\u000a of newly developed polyester mesh products have recently become available. This is the first U.S. multiinstitutional study\\u000a evaluating the initial experience of polyester mesh use for total extraperitoneal (TEP) laparoscopic inguinal hernia repair.\\u000a Between January 2000 and June 2001, 337

B. Ramshaw; F. Abiad; G. Voeller; R. Wilson; E. Mason

2003-01-01

102

Hydrolyzable polyester resins, varnishes and coating compositions containing the same  

DOEpatents

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

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

1984-01-01

103

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

104

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

Microsoft Academic Search

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

Mary M. Warnock; Mary E. Cotton

1985-01-01

105

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

Federal Register 2010, 2011, 2012, 2013

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

2011-11-09

106

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

Federal Register 2010, 2011, 2012, 2013

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

2010-06-16

107

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

Federal Register 2010, 2011, 2012, 2013

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

2011-01-18

108

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

Federal Register 2010, 2011, 2012, 2013

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

2013-06-28

109

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

Federal Register 2010, 2011, 2012, 2013

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

2012-12-03

110

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

Federal Register 2010, 2011, 2012, 2013

...Administration [A-570-905] Certain Polyester Staple Fiber From the People's Republic...second administrative review of certain polyester staple fiber (``PSF'') from the...2008--May 31, 2009. See Certain Polyester Staple Fiber From the People's...

2010-12-10

111

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...

112

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

NASA Astrophysics Data System (ADS)

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

Shyr, Tien-Wei; Shie, Jing-Wen

2012-11-01

113

Biodegradation of polyester polyurethane by endophytic fungi.  

PubMed

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

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

2011-09-01

114

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

115

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...

116

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

Federal Register 2010, 2011, 2012, 2013

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

2012-05-01

117

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

Federal Register 2010, 2011, 2012, 2013

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

2012-10-12

118

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

Federal Register 2010, 2011, 2012, 2013

...Administration [A-580-839] Certain Polyester Staple Fiber From Korea: Rescission...administrative review of the antidumping order on polyester staple fiber from Korea. See Antidumping...June 28, 2011). Scope of the Order Polyester staple fiber covered by the scope...

2011-08-24

119

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

120

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

121

Catalytic water dissociation using hyperbranched aliphatic polyester (Boltorn ® series) as the interface of a bipolar membrane  

Microsoft Academic Search

The effect of hyperbranched aliphatic polyester (Boltorn® series) on the water dissociation in bipolar membranes was firstly investigated in this paper. The bipolar membranes were prepared by immersing the anion exchange layer in a hyperbranched aliphatic polyester solution and then coating on the layer a polyphenylene oxide (SPPO) solution. The SEM observations proved the existence of hyperbranched aliphatic polyester at

Yanhong Xue; Tongwen Xu; Rongqiang Fu; Yiyun Cheng; Weihua Yang

2007-01-01

122

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

123

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

124

Electropositive bivalent metallic ion unsaturated polyester complexed polymer concrete  

DOEpatents

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

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

1981-11-04

125

Lipase-catalyzed polyester synthesis--a green polymer chemistry.  

PubMed

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 chemoenzymatic processes. New syntheses of a variety of functional polyesters and a plausible reaction mechanism of lipase catalysis are mentioned. The polymerization characteristics are of green nature currently demanded for sustainable society, and hence, desirable for conducting 'green polymer chemistry'. PMID:20431260

Kobayashi, Shiro

2010-01-01

126

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

127

Amphiphilic Dendritic Molecules: Hyperbranched Polyesters with Alkyl-Terminated Branches  

E-print Network

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

Vakni, David

128

Lipase-catalyzed polyester synthesis - A green polymer chemistry  

PubMed Central

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

Kobayashi, Shiro

2010-01-01

129

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

130

Fire behaviour related to the thermal degradation of unsaturated polyesters  

Microsoft Academic Search

In this work, the thermal and the fire behaviour of unsaturated polyester (UP) resins have been investigated. A comparison of the thermal stability of the two materials (UP resins without and with modification with DCPD grafted on the chains ends) showed that the resin with DCPD is more stable. Nevertheless, modelling of the fuel flow evolved during the degradation showed

B Mortaigne; S Bourbigot; M Le Bras; G Cordellier; A Baudry; J Dufay

1999-01-01

131

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

132

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

PubMed

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

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

2012-02-01

133

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

134

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

135

Self-assembly of amido-ended hyperbranched polyester films with a highly ordered dendritic structure.  

PubMed

Self-assemblies fabricated from dendrimers and amphiphilic polymers have demonstrated remarkable performances and a wide range of applications. Direct self-assembly of hyperbranched polymers into highly ordered macrostructures with heat-resistance remains a big challenge due to the weak amphiphilicity of the polymers. Here, we report the self-assembly of amphiphilic amido-ended hyperbranched polyester (HTDA-2) into millimeter-size dendritic films using combined hydrogen bond interaction and solvent induction. The self-assembly process and mechanism have been studied. Hydrogen bond interaction between amido-ended groups assists the aggregation of inner and outer chains of the HTDA-2, resulting in phase separation and micelle formation. Some micelles attach to and grow on the glass substrate like seedlings. Other micelles move to the seedlings and connect with their branches via solvent induction and hydrogen bond interaction, leading to the fabrication of highly ordered crystalline dendritic films that show high heat-resistance. HTDA-2 can further self-assemble into sheet crystals on the dendritic films. PMID:25148598

Zhang, Daohong; Xu, Zhicai; Li, Junna; Chen, Sufang; Cheng, Juan; Zhang, Aiqing; Chen, Shenghui; Miao, Menghe

2014-09-24

136

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

SciTech Connect

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

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

2000-09-15

137

Surface Characterization of Aliphatic Polyester -g- Phosphorylcholine Copolymers  

NASA Astrophysics Data System (ADS)

In order to control biodegradation behavior of a class of polyesters, hydrophilic functional groups were grafted onto the main chains. Phosphorylcholine (PC) molecules with azide attached at the end were synthesized. Due to their excellent biocompatibility and hydrophilicity, they have been covalently coupled to biodegradable aliphatic polyesters via a ``click'' cycloaddition reaction to produce amphiphilic graft copolymers. A series of copolymers were prepared by varying the molar incorporation of PC groups. Surface properties of the copolymers were examined to further explore their applications in drug delivery systems. Grazing angle reflection infrared spectroscopy was employed to determine segmental orientation at the film surface. XPS was used to verify surface composition. A water adsorption experiment was carried out to determine the water permeation rate. The improvement in hydrophilicity was confirmed by a water contact experiment. Results indicate that the graft copolymers were promising in drug delivery systems.

Zhang, Xiongfei; Emrick, Todd; Hsu, Shaw L.

2007-03-01

138

Amino alcohol-based degradable poly(ester amide) elastomers  

PubMed Central

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

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

2009-01-01

139

Mechanical Behavior of Fabric-Film Laminates  

NASA Technical Reports Server (NTRS)

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

Said, Magdi S.

1999-01-01

140

A method for the interpretation of pyrolysis-mass spectra of polyesters  

Microsoft Academic Search

A new method for the interpretation of pyrolysis-mass spectra of polyesters is described. The method is based on the use of table of pyrolysis-mass spectral data of polyesters. It has two steps: first, the examination of the unknown pyrolysis-mass spectrum in order to extract information about the relationship of specific ion masses with particular polyester structures; second the recongnition and

C. G. Georgakopoulos; M. Statheropoulos; G. Parissakis; G. Montaudo

1995-01-01

141

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

Microsoft Academic Search

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

L. L. Gaines; A. M. Wolsky

1982-01-01

142

A solvent-free synthesis of sucrose polyesters  

Microsoft Academic Search

A solvent-free reaction system is described for making sucrose polyesters (SPE) by interesterification of sucrose and long\\u000a chain fatty acid methyl esters. The process avoids the usual toxic solvents by using a novel two-stage reaction sequence.\\u000a In the first stage a 3:1 mole ratio of methyl esters to sucrose is reacted in the presence of potassium soaps to form a

George P. Rizzi; Harry M. Taylor

1978-01-01

143

Fungal Communities Associated with Degradation of Polyester Polyurethane in Soil  

Microsoft Academic Search

Soil fungal communities involved in the biodegradation of polyester polyurethane (PU) were investi- gated. PU coupons were buried in two sandy loam soils with different levels of organic carbon: one was acidic (pH 5.5), and the other was more neutral (pH 6.7). After 5 months of burial, the fungal communities on the surface of the PU were compared with the

Lee Cosgrove; Paula L. McGeechan; Geoff D. Robson; Pauline S. Handley

2007-01-01

144

Biodegradation of aliphatic polyester composites reinforced by abaca fiber  

Microsoft Academic Search

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

Naozumi Teramoto; Kohei Urata; Koichi Ozawa; Mitsuhiro Shibata

2004-01-01

145

Thermal conductivity of polyester-amide-imide film  

NASA Astrophysics Data System (ADS)

Thermal conductivity measurements were performed on polyester-amide-imide film from 4 to 323 K. The specimen was in the form of a stack of aluminium discs coated on both sides with film. The results exhibit a temperature dependence similar to varnish, but are about half as large in conductivity. The results, based on nineteen data points, are estimated to be accurate to about 10%.

Hust, J. G.; Boscardin, R.

146

Adhesive behavior of aluminum layers evaporated on polyester films  

NASA Astrophysics Data System (ADS)

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

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

1996-01-01

147

Curing reaction of unsaturated polyester resin modified by dicyclopentadiene  

Microsoft Academic Search

The objective of this research is to prepare modified unsaturated polyester resin(UPR) with good processibility, dimension\\u000a stability and mechanical properties. In this study, dicyclopentadiene (DCPD) is selected as a modifier and the effect of DCPD\\u000a content on the curing behavior of the modified UPR is examined via Differential Scanning Calorimetry (DSC) and Rheometrics\\u000a Dynamic Analysis (RDA) experiments. The results of

Hsien-Tang Chiu; Su-Chen Chen

2001-01-01

148

Conductive Papers Containing Metallized Polyester Fibers for Electromagnetic Interference Shielding  

Microsoft Academic Search

Conductive papers were developed for preventing or reducing electromagnetic interference (EMI), and their shielding efficiency was evaluated. This type of conductive paper consists of wood pulp, synthetic pulp and metallized polyester fibers (0.5–2.0 mm long and 14 µm in diameter) whose surfaces are coated with nickel alone (Ni-PET) or copper and nickel double layers (Ni-Cu-PET) by electroless plating. In this

Shunichi Shinagawa; Yaomi Kumagai; Kei Urabe

1999-01-01

149

Cyclic swelling as a phenomenon inherent to biodegradable polyesters.  

PubMed

The aim of this study is to evaluate and describe the phenomenon and mechanism of the spontaneous cyclic swelling and deswelling of linear and branched aliphatic polyesters in the aqueous medium. The fluctuation of gel volume in one or several cycles as an inherent property of biodegradable and bioerodible materials has not yet been described. We have observed the process at linear and branched polyesters of aliphatic ?-hydroxy acids. The period of duration of cycles was in order of hours to days, as influenced by the size of the bodies ranging from 25 to 1000 mg, the temperature in the range of 7°C-42°C, ionic strength, and pH value. The results demonstrated that swelling is accompanied by hydrolysis of ester bonds with the development of small water-soluble osmotically active molecules. After reaching a higher degree of swelling, the obstruction effect of the gel decreases and the diffusion of soluble degradation products from the body to the environment prevails. A decrease in osmotic pressure inside the body and a decrease in the hydrophilic character of the gel matrix result in deswelling by a collapse of the structure, probably due to hydrophobic interactions of nonpolar polyester chains. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3560-3566, 2014. PMID:25241844

Dittrich, Milan; Snejdrova, Eva

2014-11-01

150

Synthesis of aliphatic polyesters by polycondensation using inorganic acid as catalyst  

PubMed Central

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

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

2014-01-01

151

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

NASA Astrophysics Data System (ADS)

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

Boykin, Timothy Lamar

152

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

PubMed

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

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

2013-10-25

153

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

Federal Register 2010, 2011, 2012, 2013

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

2010-11-19

154

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

Federal Register 2010, 2011, 2012, 2013

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

2012-01-30

155

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

Federal Register 2010, 2011, 2012, 2013

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

2011-01-31

156

76 FR 40329 - Certain Polyester Staple Fiber From the People's Republic of China: Notice of Preliminary Results...  

Federal Register 2010, 2011, 2012, 2013

...A-570-905] Certain Polyester Staple Fiber From the People's Republic of China...duty order on certain polyester staple fiber from the People's Republic of China...with respect to Ningbo Dafa Chemical Fiber Co., Ltd. (``Ningbo Dafa'')...

2011-07-08

157

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

Microsoft Academic Search

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

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

2001-01-01

158

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...

159

Effect of artificial weathering on surface properties of unsaturated polyester (UP) resin  

Microsoft Academic Search

Unsaturated polyester resin samples were exposed to artificial weathering environment for different time intervals. The change of appearance, morphology, chemical structure and contact angle on unsaturated polyester resin surface before and after exposure in this environment was monitored by spectrophotometer, gloss meter, microscope, Specula Reflection Fourier Transform Infrared (SR-FTIR) spectroscopy and optical contact angle measuring device. The results showed that

Zhijun Jia; Xiaogang Li; Quanlin Zhao

2010-01-01

160

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

161

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

162

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

163

Contribution To Degradation Study, Behavior Of Unsaturated Polyester Resin Under Neutron Irradiation  

Microsoft Academic Search

Applications of unsaturated polyester thermosetting resins are numerous in construction sector, in transport, electric spare parts manufactures, consumer goods, and anticorrosive materials. This survey reports the effect of thermosetting polymer degradation (unsaturated polyester): degradation by neutrons irradiation. In order to evaluate the deterioration of our material, some comparative characterizations have been done between standard samples and damaged ones. Scanning electron

D. Abellache; A. Lounis; K. Taiebi

2010-01-01

164

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

Federal Register 2010, 2011, 2012, 2013

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

2012-09-06

165

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

Federal Register 2010, 2011, 2012, 2013

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

2012-04-11

166

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

Federal Register 2010, 2011, 2012, 2013

...A-580-839, A-583-833] Certain Polyester Staple Fiber From the Republic of Korea...reviews of the antidumping duty orders on polyester staple fiber (PSF) from the Republic...otherwise processed for spinning, of polyesters measuring 3.3 decitex (3...

2011-07-01

167

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

Microsoft Academic Search

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

Yona Eckstein

1989-01-01

168

77 FR 39990 - Certain Polyester Staple Fiber From the People's Republic of China: Preliminary Results of the...  

Federal Register 2010, 2011, 2012, 2013

...A-570-905] Certain Polyester Staple Fiber From the People's Republic of China...duty order on certain polyester staple fiber from the People's Republic of China...duty order on certain polyester staple fiber from the PRC.\\1\\ On July 28,...

2012-07-06

169

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

170

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 10 m 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

171

New Approach for Imparting Antimicrobial Properties for Polyamide and Wool Containing Fabrics  

Microsoft Academic Search

Direct fiber polymer\\/antibiotic interaction is a promising means of providing infection resistance textile fabrics. Ionic interaction between cationic reactive groups (antibiotic) and carboxylic groups in wool, wool\\/polyamide, wool\\/polyester, and polyamide was used as a tool to develop desirable, durable antimicrobial fabrics.The finishing conditions such as pH, finishing temperature, and time were studied.The results revealed that pH of the finishing bath

Samiha Mohamed Abo El-Ola

2007-01-01

172

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. PMID:24052855

Redón, Rocío; Carreón-Castro, M. Pilar; Mendoza-Martínez, F. J.

2012-01-01

173

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. PMID:23536920

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

2013-01-01

174

Development of Photocrosslinkable Urethane-Doped Polyester Elastomers for Soft Tissue Engineering  

PubMed Central

Finding an ideal biomaterial with the proper mechanical properties and biocompatibility has been of intense focus in the field of soft tissue engineering. This paper reports on the synthesis and characterization of a novel crosslinked urethane-doped polyester elastomer (CUPOMC), which was synthesized by reacting a previously developed photocrosslinkable poly (octamethylene maleate citrate) (POMC) prepolymers (pre-POMC) with 1,6-hexamethylene diisocyanate (HDI) followed by thermo- or photo-crosslinking polymerization. The mechanical properties of the CUPOMCs can be tuned by controlling the molar ratios of pre-POMC monomers, and the ratio between the prepolymer and HDI. CUPOMCs can be crosslinked into a 3D network through polycondensation or free radical polymerization reactions. The tensile strength and elongation at break of CUPOMC synthesized under the known conditions range from 0.73±0.12MPa to 10.91±0.64MPa and from 72.91±9.09% to 300.41±21.99% respectively. Preliminary biocompatibility tests demonstrated that CUPOMCs support cell adhesion and proliferation. Unlike the pre-polymers of other crosslinked elastomers, CUPOMC pre-polymers possess great processability demonstrated by scaffold fabrication via a thermally induced phase separation method. The dual crosslinking methods for CUPOMC pre-polymers should enhance the versatile processability of the CUPOMC used in various conditions. Development of CUPOMC should expand the choices of available biodegradable elastomers for various biomedical applications such as soft tissue engineering. PMID:23565318

Zhang, Yi; Tran, Richard T.; Gyawali, Dipendra; Yang, Jian

2012-01-01

175

Hygrothermomechanical evaluation of transverse filament tape epoxy/polyester fiberglass composites  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

176

Advances in Synthesis of Co- and Ter- Polycarbonates and Polyesters from Non-Petroleum Feedstocks and Kinetic Studies of Ligand Substitution from Manganese Half-Sandwich Complexes  

E-print Network

anhydrides catalyzed by transition metal complexes to yield polyesters via a chain-growth mechanism has recently gained much attention. This robust method of polyester synthesis can utilize rather inexpensive reagents to synthesize an array of polyester... from Renewable Resources ........................................... 20 Polyesters from Epoxides and Cyclic Anhydrides ......................... 22 Synthesis of One-Pot Block Terpolymers ...................................... 24...

Poland, Ross Rivers

2012-07-16

177

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

178

Mechanical and Tear Properties of Fabric/Film Laminates  

NASA Technical Reports Server (NTRS)

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

Said, Magdi A.

1998-01-01

179

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. PMID:20954726

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

2010-01-01

180

Radiation-induced changes affecting polyester based polyurethane binder  

NASA Astrophysics Data System (ADS)

The application of thermoplastic polyurethane elastomers as binders in the high energy explosives particularly when used in weapons presents a significantly complex and challenging problem due to the impact of the aging of this polymer on the useful service life of the explosive. In this work, the effects of radiation on the aging of the polyester based polyurethane were investigated using both electron beam and gamma irradiation at various dose rates in the presence and absence of oxygen. It was found by means of GPC that, in the presence and absence of oxygen, the poly (ester urethane) primarily undergoes cross-linking, by means of a carbon-centered secondary alkyl radical. It was also concluded that the polymer partially undergoes scission of the backbone of the main chain at C-O, N-C, and C-C bonds. Substantial changes in the conditions of irradiation and in dose levels did not affect the cross-linking and scission yields. Experiments were also performed with EPR spectroscopy for the purpose of identifying the initial carbon-centered free radicals and for studying the decay mechanisms of these radicals. It was found that the carbon-centered radical which is produced via C-C scission (primary alkyl radical) is rapidly converted to a long-lived allylic species at higher temperatures; more than 80% radicals are converted to allyl species in 2.5 hours. In the presence of oxygen, the allyl radical undergoes a fast reaction to produce a peroxyl radical; this radical decays with a 1.7 hour half-life by pseudo first-order kinetics to negligible levels in 13 hours. FTIR measurements were conducted to identify the radiation-induced changes to the functional groups in the polyester polyurethane. These measurements show an increase in carbonyl, amine and carboxylic groups as a result of reaction of H atoms with R-C-O·, ·NH-R and R-COO·. The FTIR results also demonstrate the production of the unsaturation resulting from hydrogen atom transfer during intrachain conversion of the primary alkyl radical to the allyl species, prompt trans-vinylene production in tetramethylene units, and hydrogen atom abstraction by alkyl radicals on neighboring chains. The production of unsaturation is substantiated by the EPR studies. Finally, a free radical mechanism is proposed for the production of cross-linking in polyester polyurethane.

Pierpoint, Sujita Basi

181

Polyester-based thin films with high photosensitivity  

SciTech Connect

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

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

2000-02-29

182

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

183

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

E-print Network

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

Brigham, Christopher J.

184

The effect of epoxy-polyester sealing of sprayed metal coatings for additional corrosion protection  

Microsoft Academic Search

Purpose – The purpose of this paper is to report salt spray testing of epoxy-polyester top-coating applied on Zn-sprayed, Al-sprayed and 85Zn-15Al-sprayed steel samples. Design\\/methodology\\/approach – In these tests, steel substrates sprayed with Zn, Al and 85Zn-15Al coatings of different average thicknesses ranging from 120 to 210 ?m were top-coated with an epoxy-polyester sealing layer. The corrosion test was performed

A. Akinci; F. Yilmaz

2011-01-01

185

Ambient temperature catalyst-free light-induced preparation of macrocyclic aliphatic polyesters.  

PubMed

The light induced, catalyst-free ambient temperature preparation of macrocyclic aliphatic polyesters is pioneered. Based on the photo-induced Diels-Alder reaction of orthoquinodimethane and acrylate moieties, cyclic polyesters of high purity are readily synthesized. Considering the high tolerance to functional groups and the orthogonality of the ligation, the reported protocol can be easily transferred to a large range of polymers, complex topologies (tadpole, sun-shaped, jellyfish, etc.) and applications. PMID:24413149

Josse, Thomas; Altintas, Ozcan; Oehlenschlaeger, Kim K; Dubois, Philippe; Gerbaux, Pascal; Coulembier, Olivier; Barner-Kowollik, Christopher

2014-02-25

186

Synthesis and applications of unsaturated polyester resins based on PET waste  

Microsoft Academic Search

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

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

2007-01-01

187

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

188

Porcine insulin biodegradable polyester microspheres: stability and in vitro release characteristics.  

PubMed

The stability of porcine insulin in biodegradable polymers, i.e., poly(DL-lactide-co-glycolide) 50:50 (50:50 DL-PLGA) and poly(L-lactide) (L-PLA) was investigated. Insulin encapsulated microspheres were fabricated from both polymers using double-emulsion-solvent evaporation and emulsion-solvent evaporation techniques and subjected to accelerated stability studies at 40 degrees C and 75% relative humidity. Porcine insulin was found to degrade in all microsphere formulations with an average of < 50% of the initial loading amount remaining intact at the end of 4 weeks. The two major degradation products observed in these formulations were determined to be A-21 desamido insulin and covalent insulin dimer with trace amounts of high molecular weight transformation products. In vitro release studies in phosphate buffered saline at 37 degrees C resulted in very slow and incomplete (< 30% in 30 days) release kinetics for all microsphere formulations. Extraction and analyses of the unreleased insulin within the microspheres revealed that an average of approximately 11% of the encapsulated insulin remained intact. The degradation products observed consisted of approximately 15% of three distinct deamidated hydrolysis products including A-21 desamido insulin, approximately 22% covalent insulin dimer, and trace amounts of high molecular weight transformation products. The degradation of porcine insulin within biodegradable polyester microspheres during stability and release studies can be attributed to the gradual decrease in the pH within the microspheres due to progressive polymer hydrolysis resulting in the production of DL-lactic and glycolic acids. The encapsulation of an acid-base indicator, bromophenol blue, in 50:50 PLGA microspheres (as a probe to estimate pH within the microspheres during accelerated stability studies) indicated that the pH decreased to approximately 3.8 after 3 weeks. PMID:10669912

Shao, P G; Bailey, L C

2000-01-01

189

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. PMID:20864156

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

2010-01-01

190

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

191

Synthesis of Polymers by Using Divalent Metal Salts of Mono(hydroxyethyl)phthalate: Metal-Containing Unsaturated Polyesters  

Microsoft Academic Search

Syntheses of metal-containing unsaturated polyesters based on divalent metal salts (I) of mono (hydroxyethyl)phthalate were investigated by the polycondensation reactions of I-glycols with maleic anhydride (MA)-phthalic anhydride (PA). Among various combinations of components, the systems of MA-PA-diethylene glycol (DEG)-Mg salt, and MA-PA-ethylene glycol (EG)-propylene glycol (PG)-Mg salt gave polyesters soluble in styrene. Viscosities of styrene solutions of the polyesters obtained

Hideaki Matsuda

1975-01-01

192

Polyrotaxanes by in situ self threading during polymerization of functional macrocycles. Part 2: Poly(ester crown ether)s  

Microsoft Academic Search

Poly(ester crown ether)s were synthesized by direct condensation of bis(5-carboxy-m-phenylene)-(3x + 2)-crown-x, x = 6,8 and 10 (1a, 1b and 1c) with bisphenols via the Higashi method. The formation of higher molecular weight poly(ester crown ether) 5 from the 32-membered crown ether 1c and bisphenol-A (2a) as compared to polyester 3 from 20-membered crown ether 1a and bisphenol-A, polyester 4

Harry W Gibson; Devdatt S Nagvekar; Jason Powell; Caiguo Gong; William S Bryant

1997-01-01

193

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

194

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.

195

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

196

Preparation and sorption studies of polyester microsphere copolymers containing ?-cyclodextrin.  

PubMed

Polyester copolymer sorbent materials that incorporate ?-Cyclodextrin (?-CD) were prepared using water-in-oil (w/o) micro-emulsion conditions at variable ?-CD: cross linker mole ratios; where the cross linker units were sebacoyl chloride (SCl) and terephthaloyl chloride (TCl). The copolymers were characterized using TGA, nitrogen adsorption, and NMR/IR spectroscopy. The dye-based sorption properties of the copolymers with p-nitrophenol (PNP) in aqueous solution were evaluated at pH 4.6 and 295 K using UV-Vis spectrophotometry. The uptake of PNP varied from 0.221 to 0.352 mmol/g, according to the nature of the cross linker and the copolymer mole ratio. The sorption capacity of SCl-based copolymers exceed that for TCl-based copolymers, and correlate with the relative swelling properties and hydrated surface areas of the sorbent frameworks. (1)H NMR spectroscopy of copolymers with low levels of linker content (i.e. SCl or TCl) indicate dual sorption sites for PNP (i.e. ?-CD inclusion sites and non-inclusion (interstitial) linker domains). The existence of dual sorption sites is similarly concluded for copolymers containing higher levels of cross linker. Inclusion complexes are firstly formed between PNP and the ?-CD inclusion sites of the copolymer; thereafter, PNP is adsorbed onto the linker domains of the copolymer sorbent framework. PMID:22944476

Wilson, Lee D; Guo, Rui

2012-12-01

197

Engineered Thermobifida fusca cutinase with increased activity on polyester substrates.  

PubMed

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

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

2011-10-01

198

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

199

Comparison of tissue integration between polyester and polypropylene prostheses in the preperitoneal space.  

PubMed

Tissue integration and implant characteristics of various biomaterials commonly used for inguinal hernia repair have not been studied extensively. The aim of this study is to compare behavior and tissue response between two new polyester prostheses and a commonly used polypropylene (PP) mesh. The polyester prostheses utilized were polyester flat (PF) and polyester soft three-dimensional (PS); the PP mesh utilized was Marlex. Eight randomly assigned 4 x 4-cm2 pieces of two different meshes were fixed in the preperitoneal space with a centrally placed single suture. Gross evaluation included shrinkage and stiffness. Histological evaluation included amount of fibrous and fat encapsulation, connective tissue, foreign-body reaction, neovascularization, hemorrhage, necrosis, and exudate. Evaluations were graded on a zero to four scale. The area and the area ratio were measured using a calibrated micrometer. PP mesh resulted in more fibrous encapsulation and stiffness than PF and PS prostheses. PP also resulted in less connective tissue formation and foreign-body reaction than PF and PS prostheses. There was no difference in fat encapsulation, necrosis, hemorrhage, or exudate between prostheses. Both polyester prostheses (PF and PS) have better tissue integration than the PP mesh, as evidenced by the higher amount of connective tissue and lower extent of fibrous encapsulation. PMID:12852503

Gonzalez, Rodrigo; Ramshaw, Bruce J

2003-06-01

200

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

PubMed

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

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

2014-12-01

201

Synthesis of amphiphilic alternating polyesters with oligo(ethylene glycol) side chains and potential use for sustained release drug delivery.  

PubMed

Novel amphiphilic alternating polyesters, poly((N-phthaloyl-l-glutamic anhydride)-co-(2-(2-(2-methoxyethoxy)ethoxy)methyl)oxirane) (P(PGA-co-ME(2)MO)), were synthesized by alternating copolymerization of PGA and ME(2)MO. The structures of the synthesized polyesters were characterized by (1)H NMR, (13)C NMR, FT-IR, and GPC analyses. Because of the presence of oligo(ethylene glycol) (OEG) side chains, the polyesters could self-assemble into thermosensitive micelles. Dynamic light scattering (DLS) showed that these micelles underwent thermoinduced size decrease without intermicellar aggregation. In vitro methyl thiazolyl tetrazolium (MTT) assay demonstrated that the polyesters were biocompatible to Henrietta Lacks (HeLa) cells, rendering their potential for drug delivery applications. Two hydrophobic drugs, rifampin and doxorubicin (DOX), were loaded into the polyester micelles and observed to be released in a zero-order sustained manner. The sustained release could be accelerated in lower pH or in the presence of proteinase K, due to the degradation of the polyester under these conditions. Remarkably, in vitro cell experiments showed that the polyester micelles accomplished fast release of DOX inside cells and higher anticancer efficacy as compared with the free DOX. With enhanced stability during circulation condition and accelerated drug release at the target sites (e.g., low pH or enzyme presence), these novel polyesters with amphiphilic structures are promising to be used in sustained release drug delivery systems. PMID:21649444

Wang, Wei; Ding, Jianxun; Xiao, Chunsheng; Tang, Zhaohui; Li, Di; Chen, Jie; Zhuang, Xiuli; Chen, Xuesi

2011-07-11

202

Carbon black-containing interpenetrating polymer networks based on unsaturated polyester\\/epoxyII. Thermal degradation behavior and kinetic analysis  

Microsoft Academic Search

Carbon black flame retardants were chosen to improve the flame resistance of interpenetrating polymer networks based on unsaturated polyester\\/epoxy due to the expansion of carbon black at elevated temperatures. Thermal degradation behaviour and kinetic parameters of this system were analysed by conventional and modulated thermogravimetric analysis (MTGA). It was found that the epoxy and polyester components decomposed individually in the

Yeng-Fong Shih; Ru-Jong Jeng

2002-01-01

203

Synthesis of aliphatic polyester hydrogel for cardiac tissue engineering.  

PubMed

Despite clinical advances, ischemic heart disease continues to be a major cause of morbidity and mortality worldwide. Prolonged cardiac ischemia and loss of cardiomyocytes frequently result in progressive pathological remodeling of the myocardium. If the heart is unable to adapt, patients may succumb to terminal heart failure. Cardiac tissue regeneration combining biodegradable biomaterials and stem cells has emerged as a new approach to restore heart function. Biomaterials, including injectable hydrogels and spongy scaffolds, can facilitate stem cell engraftment and survival and prevent adverse ventricular remodeling. Promising early results with injectable, biodegradable hydrogels for cardiac repair have provided new opportunities for designing innovative therapies to treat injured hearts. Hydrogels can be made from natural or synthetic polymers and have a water content, flexibility, and other physiochemical characteristics similar to those of living tissue, which makes them excellent candidates for tissue repair. In addition, hydrogels can be used as a vehicle to deliver cytokines or cells to the heart and can be employed to encapsulate biological macromolecules or cells and release them into the surrounding tissues during degradation. Hydrogels undergo physicochemical modifications in response to changes in temperature or pH, depending upon their polymer composition, converting from a liquid to a gel. The gel form retains cytokine molecules, allows their prolonged, controlled release, and preserves their bioactivity for extended periods. Polyethylene glycol is a water-soluble, biocompatible polymer that has negligible immunogenicity and can produce efficient conjugation of hydrogels to growth factors. In this chapter, we provide insight into the composition, polymerization, and use of a temperature-sensitive, biodegradable, aliphatic polyester hydrogel that transforms to a gel at physiological temperatures and is a potential candidate for cardiac tissue regeneration. PMID:25070326

Dhingra, Sanjiv; Weisel, Richard D; Li, Ren-Ke

2014-01-01

204

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

SciTech Connect

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

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

1993-12-31

205

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

206

Panel Fabrication  

NSDL National Science Digital Library

Proper Tool and Equipment Identification OBJECTIVES This tutorial is specifically designed for advanced students who are enrolled in their third semester of Collision Repair at UVSC. Students will learn of the different panel fabrication equipment available at UVSC to help them build their own Street Rod. Basic Body working skills will be mentioned, proper tool ...

Man??, Body

2005-11-30

207

Media Fabrics  

Microsoft Academic Search

Imagine the stories we would tell if we could construct media experiences as easily and playfully as we now use spoken language. Today, storytelling approaches are transitioning due in part to the abilities of small, mobile networked devices to capture, manipulate, share, exchange and publish visual and sound sequences. This paper explores a new paradigm we call the 'media fabric'

Glorianna Davenport; Barbara Barry; Aisling Kelliher; Paul Nemirovsky

208

Dielectric investigation of some woven fabrics  

NASA Astrophysics Data System (ADS)

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

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

2009-10-01

209

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

Microsoft Academic Search

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

T. Hanemann

2006-01-01

210

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

Microsoft Academic Search

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

K. W. Garrett; J. E. Bailey

1977-01-01

211

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

Microsoft Academic Search

This work reviews the stripping off, role of water molecules in activity, and flexibility of immobilized Candida antarctica lipase B (CALB). Employment of CALB in ring opening polyester synthesis emphasizing on a polylactide is discussed in detail. Execution of enzymes in place of inorganic catalysts is the most green alternative for sustainable and environment friendly synthesis of products on an

Ani Idris; Attaullah Bukhari

212

Mechanism of surface microcracking of matrix in glass-reinforced polyester by artificial weathering  

Microsoft Academic Search

The first stage in the deterioration of glass-fibre reinforced polyester (GRP) composites, fibre prominence, has been reported. The mechanism of the second stage, surface microcracking, is now described. Under controlled conditions GRP sheets were subjected to cyclic variation of moisture and temperature and to radiation. It is proposed that surface microcracking takes place under the combined action of radiation-induced tensile

A. Blaga; R. S. Yamasaki

1973-01-01

213

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

PubMed

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

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

2014-09-01

214

Thermal degradation and fire behaviour of unsaturated polyester with chain ends modified by dicyclopentadiene  

Microsoft Academic Search

This work deals with the thermostability and the thermal behaviour of unsaturated polyester materials with dicyclopentadiene end cap (DCPD). These new UP resins will be used for naval applications, limiting styrene emission during processing. The thermostability has been studied by thermogravimetric analysis (TGA) both in air and in nitrogen to determine thermal and thermooxidative mechanisms, and activation energy was calculated

A. Baudry; J. Dufay; N. Regnier; B. Mortaigne

1998-01-01

215

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

EPA Science Inventory

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

216

Modelling the effect of artificial weathering on abrasive wear behaviour of glass-polyester composites  

Microsoft Academic Search

Moisture absorption degrades interfacial strength and induces expansional strains in fibre-polymer composites. These strains subsequently affect the abrasive wear behaviour of composites subjected to boiling water treatment. A wear model is suggested, which quantitatively estimates the wear performance of boiling-water-treated glass-polyester composites. The theoretical model is in concurrence with experimental results.

Navin Chand; M. Fahim

1996-01-01

217

Nanoindentation and adhesion of sol-gel-derived hard coatings on polyester  

E-print Network

Nanoindentation and adhesion of sol-gel-derived hard coatings on polyester C.M. Chan, G.Z. Cao,a) H on the plastic surface. Nanoindentation analysis revealed that the coatings have a surface hardness up to 2.5 ± 0

Cao, Guozhong

218

Biodegradable Polyester, Poly[?-(4-Aminobutyl)-l-Glycolic Acid], as a Non-Toxic Gene Carrier  

Microsoft Academic Search

Purpose. The aim of this study was to develop a non-toxic polymericgene carrier. For this purpose, biodegradable cationic polymer,poly[a-(4-aminobutyl)-l-glycolic acid] (PAGA) was synthesized. PAGA wasdesigned to have ester linkage because polyesters usually showbiodegradability.

Yong-Beom Lim; Sang-Oh Han; Han-Uk Kong; Yah Lee; Jong-Sang Park; Byeongmoon Jeong; Sung Wan Kim

2000-01-01

219

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

E-print Network

polyesters, such as poly(lactic acid), poly(glycolic acid), poly(-caprolactone), and poly(lactic-co-glycolic ABSTRACT: Monomethoxy poly(ethylene glycol)-b-poly(Tyr(alkynyl)-OCA), a biodegradable amphiphilic block acid), have been widely used as hydro- phobic cores of copolymer micelles for the encapsulation

Cheng, Jianjun

220

High-etch-rate ArF BARC composed of polyester  

NASA Astrophysics Data System (ADS)

As the pattern size decreases, the thickness of resist also should be decreased owing to the pattern collapse problem. So the using of surfactant containing rinse material, instead of DI water, can be a solution to the collapse problem. The developing of Bottom Anti Reflective Coating (BARC) that has high etch rate will be helpful to the collapse issue because it enables low thickness resist process and pattern collapse will be decrease. In this paper, Polyacetal, polyacrylate and polyesters BARCs were evaluated. Polyacetal type BARC shows best coating property. Regardless of the topology, polyacetal type BARC shows good conformality. However, polyacrylate and polyesters show coating fail on the topology wafer. In terms of pattern collapse, polyacetal type BARC also shows best results. Among the three types of BARC, ArF BARC that is made by polyester resin shows highest etch rate after 2000ÊBRAC etch. However, when the etching target is 60nm, all BARCs have same etch rate. For the matching with line and space resist, all these three BARCs show good profile. However, polyester type BARC does not match with contact hole resist and could not define contact hole pattern.

Hwang, Young Sun; Jung, Jae Chang; Ban, Keun Do; Park, Sarohan; Bok, Cheol Kyu; Moon, Seung Chan; Shin, Ki Soo

2004-05-01

221

An oxygen index evaluation of flammability on modified epoxy\\/polyester systems  

Microsoft Academic Search

This article describes a study on flame retardancy conducted on a dual cure thermosetting system consisting of an epoxy resin, blended with an unsaturated polyester. Neat resin panels and glass-fibre reinforced composites were prepared utilising several structurally different flame-retardant (FR) additives. These materials were tested in order to determine the Limiting Oxygen Index (LOI), which is a measure of the

A. D. La Rosa; A. Recca; J. T. Carter; P. T. McGrail

1999-01-01

222

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

PubMed

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

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

2010-10-01

223

Polyester (Parietex) mesh for total extraperitoneal laparoscopic inguinal hernia repair: initial experience in the United States.  

PubMed

Polypropylene mesh is the most commonly used mesh for open and laparoscopic hernia repair in the United States. A variety of newly developed polyester mesh products have recently become available. This is the first U.S. multiinstitutional study evaluating the initial experience of polyester mesh use for total extraperitoneal (TEP) laparoscopic inguinal hernia repair. Between January 2000 and June 2001, 337 patients underwent 495 TEP laparoscopic inguinal hernia repairs using polyester mesh. There were 309 men and 28 women in the study, whose average age was 45 years (range, 17-80 years). The average operative time for all cases was 54.3 min (range, 18-157 min). There were no conversions to open repair and no mortality. Complications included 12 seromas/hematomas (six aspirated), chronic pain in three patients, urinary retention in two patients, and one incidence each of the following: epididimitis, prostatitis, hydrocele, and port-site cellulitis. Additionally, one patient had carbon dioxide (CO2) in the Foley bag at the end of the surgery, but a normal cystogram showed no identified bladder injury. There has been one recurrence (0.2%), occurring 4 months after surgery, which was repaired using a transabdominal laparoscopic approach. The mean follow-up period was 11 months (range, 2-22 months). There have been no documented infections of the mesh, and no mesh has been removed. This study documents a favorable initial experience with polyester mesh for TEP laparoscopic inguinal hernia repair. There were no complications related to the mesh. There may be technical and long-term advantages with the use of polyester mesh for laparoscopic inguinal hernia repair. Longer follow-up evaluation and additional studies are warranted to evaluate these potential advantages. PMID:12436235

Ramshaw, B; Abiad, F; Voeller, G; Wilson, R; Mason, E

2003-03-01

224

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

225

Electron-beam modification of textile fabrics for hydrophilic finishing  

NASA Astrophysics Data System (ADS)

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

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

2005-03-01

226

Synthesis of Functionalized Poly(ester carbonate) with Laminin-Derived Peptide for Promoting Neurite Outgrowth of PC12 cells.  

PubMed

Maleimide-functionalized poly(ester carbonate)s are synthesized by ring-opening copolymerization of furan-maleimide functionalized trimethylene carbonate (FMTMC) with L-lactide and a subsequent retro Diels-Alder reaction. The maleimide groups on poly(ester carbonate)s are amenable to Michael addition with thiol-containing molecules such as 3-mercapto-1-propanol, 2-aminoethanethiol hydrochloride, and mercaptoacetic acid under mild conditions, enabling the formation of biodegradable materials with various functional groups (e.g., hydroxyl, amine, and carboxyl). In particular, the maleimide-functionalized poly(ester carbonate) is clicked with a laminin-derived peptide CQAASIKVAV. In vitro culture of PC12 cells shows that the maleimide-functionalized polymers, especially the CQAASIKVAV-grafted one, could support cell proliferation and neurite outgrowth. The maleimide-functionalized poly(ester carbonate)s provide a versatile platform for diverse functionalization and have comprehensive potential in biomedical engineering. PMID:24962245

Xing, Dongming; Ma, Lie; Gao, Changyou

2014-10-01

227

Triaxial Fabrics  

NASA Technical Reports Server (NTRS)

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

1981-01-01

228

Preparation and Characterization of Polyester–Glycidyl Methacrylate PolyHIPE Monoliths to Use in Heavy Metal Removal  

Microsoft Academic Search

Polyester–glycidyl methacrylate (GMA)-based poly(high internal phase emulsion)s (polyHIPEs) with 85% internal phase were prepared by using unsaturated polyester resin (UPR), glycidyl metahacrylate and divinylbenzene (DVB) or styrene (St) with triethanolamine (TEA) as an emulsifier in the presence of a porogen. Porous monoliths were obtained by a removal of internal phase after curing of dispersed phase at 80°C. Morphologies and surface

E. Hilal Mert; Mehmet Arif Kaya; Hüseyin Y?ld?r?m

2012-01-01

229

Novel DCPD-modified polyester containing epoxy groups: thermal, viscoelastic, and mechanical properties of their wood flour filled copolymers  

Microsoft Academic Search

In this article, the synthesis of novel DCPD-modified polyesters containing epoxy groups and their possible utilization as\\u000a polar matrices for wood flour filled copolymers have been studied. The novel DCPD-modified polyester containing epoxy groups\\u000a was prepared during three-step process. First, the addition reaction of maleic acid to DCPD norbonenyl double bond has been\\u000a performed. Then, the polyesterification of acidic ester

Marta Worzakowska

230

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

231

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

PubMed

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

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

2014-01-01

232

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

233

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

PubMed Central

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

Carrion, Francisco; Montalban, Laura; Real, Julia I.

2014-01-01

234

Synthesis of Polymers by Using Divalent Metal Salts of Mono(hydroxyethyl)phthalate: Metal-Containing Unsaturated Polyesters with Pendent Methacrylate Groups  

Microsoft Academic Search

Syntheses of novel metal-containing unsaturated polyesters having pendent methacrylate groups obtained by use of divalent metal salts of mono(hydroxyethyl)phthalate-maleic anhydride (MA)-glycidyl methacrylate (GMA) reactions were investigated. The yields were generally high. The metal-containing polyesters obtained were slightly yellow-brown solids, and the molecular weights ranged from 1546 to 2174, depending on the mole ratio of feed. Among them, the polyesters obtained

Hideaki Matsuda

1976-01-01

235

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

236

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

Microsoft Academic Search

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

A. Blaga; R. S. Yamasaki

1973-01-01

237

Synthesis and characterization of polyesters derived from succinic acid, ethylene glycol and 1,3-propanediol  

Microsoft Academic Search

Poly(ethylene succinate) (PES), poly(trimethylene succinate) (PTS) and their copolyesters with various compositions were synthesized through a direct polycondensation reaction with titanium tetraisopropoxide as the catalyst. The results of intrinsic viscosity and GPC have proven successful in preparing high molecular weight polyesters. The compositions and the sequence distributions of the copolyesters were determined by analyses of 1H NMR and 13C NMR

Chia-Jung Tsai; Wei-Che Chang; Chi-He Chen; Hsin-Ying Lu; Ming Chen

2008-01-01

238

Studies on Water Absorption of Bamboo-Polyester Composites: Effect of Silane Treatment of Mercerized Bamboo  

Microsoft Academic Search

The effect of silane treatments on the water absorption properties of mercerized bamboo matting reinforced polyester composites were investigated. Treatments using ?-Aminopropyltriethoxy silane, 3-trimethoxysilylpropyl methacrylate, Vinyltris(2-methoxyethoxy)silane, Bis[3-(triethoxysilyl)propyl] tetrasulfide, 3-aminopropyltrimethoxy silane and n-Octyltrimethoxy silane were carried out to improve the water resistant property of the bamboo fibers. Water absorption in the composites was studied by long-term immersion and 2 h boiling in

Pradeep K. Kushwaha; Rakesh Kumar

2009-01-01

239

Effect of water absorption on the mechanical properties of hemp fibre reinforced unsaturated polyester composites  

Microsoft Academic Search

Hemp fibre reinforced unsaturated polyester composites (HFRUPE) were subjected to water immersion tests in order to study the effects of water absorption on the mechanical properties. HFRUPE composites specimens containing 0, 0.10, 0.15, 0.21 and 0.26 fibre volume fraction were prepared. Water absorption tests were conducted by immersing specimens in a de-ionised water bath at 25°C and 100°C for different

H. N. Dhakal; Z. Y. Zhang; M. O. W. Richardson

2007-01-01

240

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

241

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

Microsoft Academic Search

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

Zaki Ajji

2005-01-01

242

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

Microsoft Academic Search

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

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

2001-01-01

243

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

244

The substitution of sucrose polyester for dietary fat in obese, hypercholesterolemic outpatients13  

Microsoft Academic Search

Our aim was to determine the effects of the substitution of sucrose polyester (SPE) for dietary fat in a 16-week outpatient study in 36 obese subjects with primary hypercholes- terolemia. The subjects were randomized into three groups who followed a 16-week treatment period where all subjects received hypocaloric diets which provided approximately 7 kcal\\/lb body weight, a polyunsaturate\\/saturated (P\\/S) fat

MJ Mellies; C Vitale; Ri Jandacek; Ci Glueck

245

Synthesis and Characterization of Solventless Polyester Varnish Based on Di Cyclo Penta Diene (DCPD)  

Microsoft Academic Search

Solventless polyester varnish was synthesized by polyesterification reaction of fumaric acid (FA), propylene glycol (PG) and dicyclo penta diene (DCPD) using triphenyl phenol (TPP) as accelerator. The resulting material was characterized by FT-IR and NMR spectroscopy. The electrical properties of varnish were also measured; volume resistivity was found 5.22 × 10 Ohm-cm at room temperature, which fulfills main requirement of electrical insulating material.

Bilson Shukla; Varun Dixit; Reena Singhal; A. K. Nagpal; Pradeep Kr. Singh

2007-01-01

246

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

SciTech Connect

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

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

1993-12-31

247

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

PubMed

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

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

2009-12-01

248

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

PubMed Central

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

2014-01-01

249

Occupational allergic contact dermatitis to cobalt octoate included as an accelerator in a polyester resin.  

PubMed

A 46-year-old woman, who worked as a laminator of spa baths, presented with hand dermatitis, which was suspected to be related to her occupation. Patch testing revealed strong reactions to both cobalt chloride and a polyester resin that the patient had been using at her workplace. She also reacted to latex and had been wearing cotton gloves underneath rubber gloves at work. It was later discovered that cobalt octoate (synonym: cobalt-2-ethylhexanoate), a compound not listed on the manufacturer's material safety data sheet, was included as an accelerator in the polyester resin. She was then tested to cobalt octoate, which was also strongly positive. Her successful treatment included protection of her hands at work with cotton lined PVC gloves. This case highlights the role of cobalt salts as sensitizers and their presence as accelerators used in polyester resins, and the importance of recognizing concomitant latex allergy that may complicate occupational dermatitis. It also illustrates the difficulties in relying on material safety data sheets to identify all possible allergens. PMID:16637815

Anavekar, Namrata S; Nixon, Rosemary

2006-05-01

250

Recovery of microorganisms on fabric materials after low water temperature washing with non-oxidizing acidic bleaching formulation by culture method.  

PubMed

The recovery of microorganisms to different fabrics was evaluated after a washing process combined with a food-grade non-oxidizing acidic formulation and low washing water temperature. Cotton, polyester and a polyester/cotton blend fabric samples were inoculated with Escherichia coli, Listeria innocua and Saccharomyces cerevisiae, then dried for 1 day. They were separately placed in a simulated fabric washer and decontaminated for 1 and 10 min with the acidic formulation at 23 °C water washing temperature. The combination of direct detecting and dilution methods was used to detect survivors on fabrics. The use of ? 0.1% acidic formulation in the washing process significantly increased the efficacy of the washing for all fabric samples. Microorganisms on the cotton and mixed fabric appeared to bind more strongly and were more resistant to the washing process. No viability was observed on the fabric swatches at 1 cfu/sample detection limit when the washing process was combined with 0.5% acidic formulation in the 10 min washing cycle. These findings can be used to increase the efficiency of sanitizing fabrics in an environmentally friendly way, for remove harmful microorganisms from them and reduce cross-contamination. PMID:25252345

Lee, Jaesung; Lopes, John A; Pascall, Melvin A

2014-09-01

251

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

PubMed

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

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

2013-04-15

252

Development of polyester-based bamboo charcoal and lyocell-blended union fabrics for healthcare and hygienic textiles  

Microsoft Academic Search

Wearing of suitable dresses in hospitals and health clubs by the doctor and supporting staff has been accorded a very high priority by the hospital administration in order to protect them from getting infected by the germs and microorganisms and also from spreading the diseases to other patients. Due to the increase in awareness and concern about the healthcare textiles,

P Kandhavadivu; C Vigneswaran; T Ramachandran; B Geethamanohari

2011-01-01

253

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

Microsoft Academic Search

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

Mohammad Mirjalili; Loghman Karimi

2012-01-01

254

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

255

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

PubMed Central

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

Diaz, Angelica; Katsarava, Ramaz; Puiggali, Jordi

2014-01-01

256

Journal of Materials Science, 2009. 44(6): p. 1485-1493. Compressive and Ultrasonic Properties of Polyester/Fly Ash Composites  

E-print Network

of Polyester/Fly Ash Composites Pradeep K. Rohatgi1 , Takuya Matsunaga1 and Nikhil Gupta2 1 University. In the present study hollow fly ash particles, called cenospheres, are used as fillers in polyester matrix. Numerous defects present in fly ash particles caused a reduction in the strength of the composite. However

Gupta, Nikhil

257

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

258

Utilization of biopolymer in resist printing of linen fabrics using reactive dyes.  

PubMed

A novel utilization of chitosan as a cationic biopolymer in the chemical resist printing of linen fabrics and its polyester blend using reactive dyes. The effects of ratio and concentration of various resist-printing agents and processing conditions are observed and discussed. The concentration of chitosan, type of resist agent, and the ratio of chitosan to resist agent were varied to determine their effects on the efficiency of resist-printing. Regardless of the type of fabric, the resist effect on printed fabrics expressed as % decrease in K/S was obtained at optimal chitosan concentration of 1% with a mixture of chitosan/maleic acid as a resist salt at a ratio of 25:75. Thus, chitosan can be used pure or in admixture with different resist salts successfully in chemical resist printing. PMID:24053837

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

2013-11-01

259

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

PubMed

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

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

2005-12-01

260

Laparoscopic ventral hernia repair using expanded polytetrafluoroethylene–polyester mesh compound  

Microsoft Academic Search

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

M. Farrakha

2006-01-01

261

Preparation and reversible photo-crosslinking\\/photo-cleavage behavior of 4-methylcoumarin functionalized hyperbranched polyester  

Microsoft Academic Search

A novel hyperbranched polymer endcapped with 4-methylcoumarin group (MCTH40) was prepared via thiol–ene addition reaction of thiol-modified hyperbranched polyester (fully thioglycolic acetate of Boltorn™ H40, TAH40) with a vinyl monomer (7-(4-vinyl-benzyloxyl)-4-methylcoumarin, VBMC), and characterized with 1H NMR and FT-IR spectroscopies. Its reversible photo-crosslinking\\/photo-cleavage behavior was evaluated based on the UV–vis spectroscopic analysis, and compared with the linear polymer, poly(7-(4-vinyl-benzyloxyl)-4-methylcoumarin (PVBMC)).

Qi Fu; Liangliang Cheng; Yong Zhang; Wenfang Shi

2008-01-01

262

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

263

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

264

Fabric-FOSS Module  

NSDL National Science Digital Library

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

Web, Foss

2011-12-14

265

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

266

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

267

Hyperbranched Aliphatic Polyester Modified Activated Carbon Particles with Homogenized Surface Groups  

NASA Astrophysics Data System (ADS)

The hyperbranched aliphatic polyester grafted activated carbon (HAPE-AC), was successfully prepared by the simple "one-pot" method. The surface functional groups of commercial activated carbon particles were homogenized to hydroxyl groups by being oxidized with nitric acid and then reduced with lithium tetrahydroaluminate (LiAlH4) at first. Secondly, the surface hydroxyl groups were used as the active sites for the solution polycondensation of the AB2 monomer, 2, 2-bis(hydroxymethyl)propionic acid (bis-MPA), with the catalysis of p-toluenesulfonic acid (p-TSA). The homogenization of the surface groups of the activated carbon particles and the graft polymerization of the hyperbranched aliphatic polyester were investigated by X-ray photoelectron spectroscopy (XPS) technique. The products were also characterized with Fourier transform infrared (FT-IR) and scanning electron microscope (SEM). The competitive adsorption properties of the products toward the heavy metal ions (Cu(II), Hg(II), Zn(II), and Cd(II)) also proved the translations of the surface groups.

Liu, Peng; Zhang, Liuxue

268

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

269

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

PubMed

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

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

2010-01-01

270

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

NASA Astrophysics Data System (ADS)

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

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

2012-08-01

271

Fabrics coated with lubricated nanostructures display robust omniphobicity.  

PubMed

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

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

2014-01-10

272

Surface modification by low-pressure glow discharge plasma of an unsaturated polyester resin: effect on water diffusivity and permeability  

Microsoft Academic Search

Unsaturated polyester resin (UPR) films have been modified by a tetrafluoromethane microwave plasma. The treated surface morphologies investigated by contact angle, atomic force microscopy and permeation measurements show that the CF4 plasma treatment decreases drastically the surface energy by increasing the hydrophobic character. The surface modification due to plasma fluorination decreases the water content diffusing through the UPR film and

S. Marais; M. Métayer; M. Labbé; J. M. Valleton; S. Alexandre; J. M. Saiter; F. Poncin-Epaillard

1999-01-01

273

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

Microsoft Academic Search

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

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

2003-01-01

274

Polymerization by phase transfer catalysis. 27. Synthesis of polyesters containing silicon or germanium. Influence of the base concentration  

Microsoft Academic Search

Polyesters derived from diphenols containing Si or Ge and isophthalic and terephthalic acids dichlorides have been synthesized using phase transfer conditions, and characterized by spectroscopic methods. Two phase transfer catalysts and three molar ratios NaOH\\/diphenol were used, and the results evaluated by the yields and the inherent viscosity values; these are compared with those obtained without catalyst. When the catalysts

L. H. Tagle; F. R. Diaz; M. Nuñez; F. Canario

2003-01-01

275

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

E-print Network

D and 2D NMR experiments also illustrated substantial differences in the degree of motional dynamicsSolid-State 13C NMR of Liquid Crystalline Polyesters: Variations in Morphology, Alignment liquid crystals. 13C NMR experiments showed that the nematic ordering achieved by these synthetic

Frydman, Lucio

276

Long-term field performance of a polyester-based long-lasting insecticidal mosquito net in rural Uganda  

Microsoft Academic Search

BACKGROUND: In order to evaluate whether criteria for LLIN field performance (phase III) set by the WHO Pesticide Evaluation Scheme are met, first and second generations of one of these products, PermaNet®, a polyester net using the coating technology were tested. METHODS: A randomized, double blinded study design was used comparing LLIN to conventionally treated nets and following LLIN for

Albert Kilian; Wilson Byamukama; Olivier Pigeon; Francis Atieli; Stephan Duchon; Chi Phan

2008-01-01

277

Carbon black containing interpenetrating polymer networks based on unsaturated polyester\\/epoxy III: thermal and pyrolysis analysis  

Microsoft Academic Search

In this study, carbon black flame retardants were chosen to improve the flame resistance of the interpenetrating polymer networks (IPNs) based on unsaturated polyester\\/epoxy due to the expansion of carbon black at elevated temperatures. The results of DSC reveal that the Tg of the IPN sample became indistinct as the carbon black was added. This is due to the increase

Yeng-Fong Shih; Ru-Jong Jeng; Kuo-Min Wei

2003-01-01

278

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

SciTech Connect

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

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

1988-03-15

279

A study of the combustion and fire-retardance behaviour of unsaturated polyester\\/phenolic resin blends  

Microsoft Academic Search

The thermal degradation and combustion behaviour of an interpenetrating network (IPN) structure of unsaturated polyester UP resin and a resole type of phenolic resin was studied. Thermal gravimetric analysis (TGA) was used to monitor the degree of thermal decomposition for the UP\\/phenol IPN structure and the change of the oxygen index (OI) was used to describe the variation of the

H.-T Chiu; S.-H Chiu; R.-E Jeng; J.-S Chung

2000-01-01

280

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".

281

Contextualizing urban mobile fabrics  

E-print Network

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

Lin, Michael Chia-Liang

2007-01-01

282

Fabrics with tunable oleophobicity  

E-print Network

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

McKinley, Gareth H.

283

DESIGN [fabrication] BUILD  

E-print Network

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

Rader, Nicolas Glen

2006-01-01

284

Photonic switching fabrics  

Microsoft Academic Search

The strengths and limitations of the photonic technology are reviewed, beginning with the temporal bandwidth limitations of photonic devices and then focusing on spatial bandwidth, commonly referred to as the parallelism of optics, and how it can be used in photonic fabrics. Some of the proposed photonic switching fabrics that are based on guided-wave devices are discussed, comprising switching fabrics

H. Scott Hinton

1990-01-01

285

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

SciTech Connect

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

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

1997-07-07

286

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

287

Calcarides A-E, Antibacterial Macrocyclic and Linear Polyesters from a Calcarisporium Strain  

PubMed Central

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

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

2013-01-01

288

Identification of the ions produced by fast atom bombardment mass spectrometry in some polyesters and polyamides  

SciTech Connect

Fast atom bombardment (FAB) mass spectrometry was applied to the analysis of two polyesters, poly(ethylene adipate) and poly(epsilon-caprolactone), and two polyamides, Nylon 6.6 and Nylon 6. The peaks present in the spectra of the crude polymers were identified as corresponding to protonated molecular ions of preformed cyclic oligomers and of low molecular weight compounds contained in the polymer samples; these species were desorbed intact from the glycerol matrix under FAB conditions. When the polymers investigated were accurately purified from low molecular weight compounds, no significant peaks were observed in their FAB mass spectra. Instead, the FAB mass spectra of the mixtures extracted from the polymers were found to be very similar to those obtained for crude polymers.

Ballistreri, A.; Garozzo, D.; Giuffrida, M.; Montaudo, G.

1987-09-01

289

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

PubMed Central

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

Goerz, Oliver

2014-01-01

290

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

SciTech Connect

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

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

2011-02-25

291

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

PubMed

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

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

2014-01-16

292

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

293

Photochemical cutting of fabrics  

DOEpatents

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

Piltch, Martin S. (Los Alamos, NM)

1994-01-01

294

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

295

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. PMID:24056469

Zafar, Urooj; Houlden, Ashley

2013-01-01

296

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

297

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

298

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

PubMed

This study determined the efficacy of a radiant barrier material used in the construction industry to moderate summer temperatures in polyethylene calf hutches. The cover consisted of a single layer of two-sided reflective aluminized polyester film with a center polyester scrim reinforcement (reflectivity?=?95%). At each of two dairies, six hutches containing a young calf were either uncovered (control) or had reflective covers across the top and sides of the hutch, leaving the front, back, and 1.2?×?1.8-m attached outdoor wire pen exposed. Duplicate loggers mounted 20 cm above the flooring in the center of each hutch recorded interior temperature at 30-min intervals over 22 days during late August to early September. The mean daily interior peak temperatures in each of the hutches over 21 days of observation were significantly less (P?

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

2014-11-01

299

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

300

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

301

Polymer radiation curing: polyester resins. January 1973-December 1988 (Citations from the Rubber and Plastics Research Association data base). Report for January 1973-December 1988  

SciTech Connect

This bibliography contains citations concerning the formulations and processes for radiation curing on polyester resins. Effects of radiation curing on polyester resins are also discussed. Electron-beam and ultraviolet radiation are emphasized. Polymer crosslinking by such electromagnetic wave radiation as in the visible wavelength is also examined. Applications in adhesives, coatings, lacquers, and printing inks are included. (Contains 200 citations fully indexed and including a title list.)

Not Available

1989-01-01

302

Interpenetrating-network formation during electron beam crosslinking of an unsaturated polyester-1,6-hexanediol diacrylate monomer system  

NASA Astrophysics Data System (ADS)

The progress of electron beam (EB) crosslinking of an unsaturated polyester (UP)-hexanediol diacrylate (HDDA) monomer mixture was monitored by different methods. The gel content measured by solvent extraction was found rather high already at relatively low doses. The physical changes in the system during crosslinking were followed by differential scanning calorimetry (DSC) and dielectric spectroscopy. The DSC results show a shift in T g with increasing irradiation dose and the beginning of thermal reaction at about 150°C. By irradiation the peaks of the dielectric spectra are broadened and the oscillator strength is reduced. By FTIR analysis it was found that the double bond content of the unsaturated polyester changes only slightly while that of the monomer decreases steeply with the dose. Based on these results the formation of interpenetrating network is probable in the case of UP/HDDA system.

Takács, Erzsébet

303

Fabrics for aeronautic construction  

NASA Technical Reports Server (NTRS)

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

Walen, E D

1918-01-01

304

Novel gradient casting method provides high-throughput assessment of blended polyester poly(lactic-co-glycolic acid) thin films for parameter optimization.  

PubMed

Pure polymer films cannot meet the diverse range of controlled release and material properties demanded for the fabrication of medical implants or other devices. Additives are added to modulate and optimize thin films for the desired qualities. To characterize the property trends that depend on additive concentration, an assay was designed which involved casting a single polyester poly(lactic-co-glycolic acid) (PLGA) film that blends a linear gradient of any PLGA-soluble additive desired. Four gradient PLGA films were produced by blending polyethylene glycol or the more hydrophobic polypropylene glycol. The films were made using a custom glass gradient maker in conjunction with a 180 cm film applicator. These films were characterized in terms of thickness, percent additive, total polymer (PLGA+additive), and controlled drug release using drug-like fluorescent molecules such as coumarin 6 (COU) or fluorescein diacetate (FDAc). Material properties of elongation and modulus were also accessed. Linear gradients of additives were readily generated, with phase separation being the limiting factor. Additive concentration had a Pearson's correlation factor (R) of >0.93 with respect to the per cent total release after 30 days for all gradients characterized. Release of COU had a near zero-order release over the same time period, suggesting that coumarin analogs may be suitable for use in PLGA/polyethylene glycol or PLGA/polypropylene glycol matrices, with each having unique material properties while allowing tuneable drug release. The gradient casting method described has considerable potential in offering higher throughput for optimizing film or coating material properties for medical implants or other devices. PMID:22293582

Steele, Terry W J; Huang, Charlotte L; Kumar, Saranya; Irvine, Scott; Boey, Freddy Yin Chiang; Loo, Joachim S C; Venkatraman, Subbu S

2012-07-01

305

Enzymatic and whole-cell synthesis of lactate-containing polyesters: toward the complete biological production of polylactate  

Microsoft Academic Search

The importance of polylactic acid, a representative bio-based polyester, has been established on a worldwide scale in response\\u000a to emerging global environmental problems such as green house gas emission and limited petroleum consumption. The current\\u000a methods for generating this bio-based polymer involve biological synthesis and lactic acid (LA) fermentation, followed by\\u000a chemical ring-opening polymerization. Among the research community working on

Ken’ichiro Matsumoto; Seiichi Taguchi

2010-01-01

306

Carbon dioxide resistance of fiberglass oil field pipe made from aromatic amine cured epoxy, vinyl ester and isophthalic polyester resins  

SciTech Connect

Unlined aromatic amine cured epoxy fiberglass piping systems have been successfully used to handle oil field services requiring resistance to carbon dioxide. Fiberglass pipe made from vinyl ester and premium isophthalic polyester resins have also been proposed for use in this type of service. This paper presents test data comparing the carbon dioxide resistance of fiberglass pipe made from theses resins. Test data for fiberglass pipe exposed to carbon dioxide containing 5% hydrogen sulfide is also presented.

Oswald, K.J.

1988-01-01

307

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

308

Screening of tropical fungi producing polyethylene terephthalate-hydrolyzing enzyme for fabric modification.  

PubMed

Microfungi were selectively isolated for production of polyethylene terephthalate (PET) fiber-degrading enzymes potentially to be used to modify the surface of polyester fabric. A range of fungi were isolated from plant surfaces and soil samples using a polycaprolactone (PCL) plate-clearing assay technique, and screened for cutinolytic esterase (cutinase) activity. Twenty-two of 115 isolates showed clearing indicating the production of cutinase. The ability of the fungi to produce cutinase in mineral medium (MM) using either potato suberin or PET (1 cm of untreated pre-washed PET fiber) fiber as substrates was assessed based on the hydrolysis of p-nitrophenyl butyrate (p-NPB). All isolates exhibited activity towards p-NPB, isolate PBURU-B5 giving the highest activity with PET fiber as an inducer. PBURU-B5 was identified as Fusarium solani based on its conidial morphology and also nucleotide sequencing from internal transcribed spacer region of the ribosomal RNA gene (rDNA-ITS). Enzymatic modification of PET cloth material properties using crude enzyme from strain PBURU-B5 showed hydrolysis of ester bonds of the PET fiber. The modification of the PET fabric resulted in increase of water and moisture absorption, and general enhancement of hydrophilicity of the fabric, properties that could facilitate processing of fabric ranging from easier dyeing while also yielding a softer feeling fabric for the user. PMID:18449587

Nimchua, Thidarat; Eveleigh, Douglas E; Sangwatanaroj, Usa; Punnapayak, Hunsa

2008-08-01

309

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

310

Enzymatic and whole-cell synthesis of lactate-containing polyesters: toward the complete biological production of polylactate.  

PubMed

The importance of polylactic acid, a representative bio-based polyester, has been established on a worldwide scale in response to emerging global environmental problems such as green house gas emission and limited petroleum consumption. The current methods for generating this bio-based polymer involve biological synthesis and lactic acid (LA) fermentation, followed by chemical ring-opening polymerization. Among the research community working on polyhydroxyalkanoate polyesters, the prospect of direct biological synthesis of LA into a polymeric form is very attractive from the academic and industrial perspectives. In 2008, this challenge was met for the first time by the discovery of an "LA-polymerizing enzyme". Using this novel enzyme, the metabolic engineering approach outlined here provided an entirely new, single organism generation of the polymer. This is a major breakthrough in the field. In this review, we provide an overview of the whole-cell synthesis of LA-containing polyesters in comparison with conventional lipase-catalyzed polymer synthesis in terms of both the concepts and strategies of their synthetic processes. PMID:20012279

Matsumoto, Ken'ichiro; Taguchi, Seiichi

2010-01-01

311

Damage of polyesters by the atmospheric free radical oxidant NO3 •: a product study involving model systems  

PubMed Central

Summary Manufactured polymer materials are used in increasingly demanding applications, but their lifetime is strongly influenced by environmental conditions. In particular, weathering and ageing leads to dramatic changes in the properties of the polymers, which results in decreased service life and limited usage. Despite the heavy reliance of our society on polymers, the mechanism of their degradation upon exposure to environmental oxidants is barely understood. In this work, model systems of important structural motifs in commercial high-performing polyesters were used to study the reaction with the night-time free radical oxidant NO3 • in the absence and presence of other radical and non-radical oxidants. Identification of the products revealed ‘hot spots’ in polyesters that are particularly vulnerable to attack by NO3 • and insight into the mechanism of oxidative damage by this environmentally important radical. It is suggested that both intermediates as well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions. PMID:24204400

Goeschen, Catrin

2013-01-01

312

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

313

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

314

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

315

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

316

Counterion Dynamics in Polyester-Sulfonate Ionomers with Ionic Liquid Counterions  

SciTech Connect

Conventional sodium cations (Na{sup +}) in sulfonated polyester ionomers were replaced with ammonium-based ionic liquid counterions. Counterion dynamics were measured by dielectric spectroscopy and linear viscoelastic response via oscillatory shear. Ion exchange from sodium counterions to ionic liquid counterions such as tetramethylammonium and tetrabutylammonium showed an order of 10{sup 4} increase in conductivity compared with sodium counterions, primarily attributed to weaker ionic interactions that lower the glass transition temperature. Electrode polarization was used in conjunction with the 1953 Macdonald model to determine the number density of conducting counterions and their mobility. Conductivity and mobility exhibit Vogel-Fulcher-Tammann (VFT) temperature dependences and both increased with counterion size. Conducting counterion concentrations showed Arrhenius temperature dependences, with activation energy reduced as counterion size increased. When ether-oxygen was incorporated into the mobile cation structure, self-solvating ability notably increased the conducting ion concentration. Weakened ion pairing interactions prove favorable for fundamental design of single-ion conductors for actuators, as ionic liquid counterions can provide both larger and faster strains, required by such electro-active devices.

Tudryn, Gregory J.; Liu, Wenjuan; Wang, Shih-Wa; Colby, Ralph H. (Penn)

2012-04-02

317

Synthesis and characterization of liquid crystalline polyester/graphene and a study of their properties.  

PubMed

A new rod-like thermotropic liquid crystalline polyester (TLCP) material and its nanocomposites based on different concentrations of graphene were synthesized by in-situ high-temperature solution polymerization. The resulting nanocomposites were characterized using XRD, microscopic analysis (POM, SEM, and TEM), spectroscopic analysis (FT-IR, UV-Vis, and fluorescence), and thermal analysis (TGA and DSC). The XRD and POM methods showed that the composite materials exhibited only the nematic phase. The TEM images revealed that the graphene were distributed in the polymer with sizes ranging from 100 to 200 nm. The absorption spectroscopy data showed that the electronic properties of graphene were mostly retained without damaging their two-dimensional electronic properties, together with the analysis of the maximum absorption spectrum and concentration of the composites in terms of the Lambert-Beer law. The fluorescence from the TLCP moiety was almost completely quenched and red shifted by graphene, indicating that the linkage mode facilitated effective energy and electron transfer between the rod-like TLCP and the extended pi-system of graphene. Therefore, this novel nanocomposite material exhibits excellent thermal properties based on the thermogravimetric analysis. PMID:22755077

Hu, Wu-Quan; Zhu, Zong-Zhen; Jin, Jun; Dong, Zheng-Ping; Zhong, Xing; Zhou, Jing-Hui; Da, Shi-Jun; Li, Rong

2012-03-01

318

Conversion of polyester/cotton industrial wastes to higher value products: Final report  

SciTech Connect

Several polyster/cotton waste blends were successfully used as feedstock to make injection molded products. Nucleating and plasticizing additives (commonly required in the production process) were found to be unnecessary; their functions were fulfilled by the cotton component of the waste feedstock. The properties of the injection molded parts were comparable generally to those of a great many other plastics. Cotton caused a notable increase in stiffness (modulus) of the molded part, but failed to produce a significant increase in tensile strength. Plant trials revealed difficulties that were unobserved in the smaller scale runs: sticking in the mold, release of water and other volatiles at the molding temperature, and intermittent flow. Sticking in the mold probably can be solved by including a small amount of mold release compound in the formulation just prior to pelletization. The problems of release of volatiles and intermittent flow can possibly be solved. Polyester/cotton molded products would have a price advantage as feedstock in the commodity thermoplastics market, but it is possible that this could be dissipated by higher molding costs.

Cates, D.

1986-10-30

319

Geometrically structured implants for cranial reconstruction made of biodegradable polyesters and calcium phosphate/calcium carbonate.  

PubMed

The aim of this study was the development of a processing pathway for manufacturing of biodegradable skull implants with individual geometry. The implants on the basis of polylactide and calcium phosphate/calcium carbonate were prepared by a combination of hot pressing and gas foaming. On the inside, the implant consists of a macroporous and faster degradable material (poly(D,L-lactide)+CaCO3) to allow the ingrowth of bone cells. The pore size is in the range of 200-400 microm. On the outside, the implant consists of a compact and slower biodegradable material (poly(L-lactide) and calcium phosphate) to ensure mechanical stability and protection. To overcome problems like inflammatory reactions caused by acidic degradation products of polylactide, the polyester was combined with basic filling materials (calcium salts). The filler neutralises the lactic acid produced during polymer degradation and increases the bioactivity of the material. The stabilised pH was demonstrated by long-term in vitro pH studies. Over a time period of 250 d in demineralised water, the pH was in the physiological range. The in vitro biocompatibility was shown by cell cultures with human osteoblasts. A good proliferation of the cells was observed over the whole test period of 4 weeks. PMID:14643598

Schiller, Carsten; Rasche, Christian; Wehmöller, Michael; Beckmann, Felix; Eufinger, Harald; Epple, Matthias; Weihe, Stephan

2004-01-01

320

Technical and economic feasibility of polyester dyeing wastewater treatment by coagulation/flocculation and Fenton's oxidation.  

PubMed

This study aims to investigate the efficiency of individual and integrated processes applied to organic matter abatement and biodegradability improvement of a polyester dyeing wastewater, namely coagulation/flocculation combined with Fenton's reagent (Approach 1), Fenton oxidation alone (Approach 2) and its integration with coagulation/flocculation (Approach 3). The effects of Fe2+ dose, initial concentration of the oxidant (H202) and temperature during Fenton's oxidation were evaluated in Approaches 1 and 2, whereas in Approach 3 the influence ofpH and flocculant dose was also assessed, during the coagulation/flocculation stage. Toxicity and biodegradability of the final effluent were also evaluated. After oxidation, a slight increase in the specific oxygen uptake rate of the effluent was observed (from 27.0 up to 28.5-30.0mg O2/(gVSSh)) and the inhibition to Vibrio fischeri was eliminated. An effluent that complies with discharge standards was obtained in all cases; however, Approach 3 revealed to be a promising solution for treating this effluent as it leads to smaller operating costs. Therefore, the use of dissolved iron resulting from Fenton's oxidation as coagulant in the second stage was shown to be an innovative, efficient and economically attractive strategy for treating these effluents. PMID:24701928

Rodrigues, Carmen S D; Boaventura, Rui A R; Madeira, Luis M

2014-01-01

321

Dielectric Properties and Coulomb Blockade Effect in Nano-Ag/Silicone Resin Modified Polyester Composite  

NASA Astrophysics Data System (ADS)

In order to modify material properties, nano Ag (diameter less than 20 nm) was successfully made from Ag colloidal sol and uniformly dispersed into silicone resin modified polyester (SP). The dielectric properties of the composite were studied. Resistivity- temperature characteristic of the composite is some different from that of pure SP. The maximal breakdown voltage of the composite is 112% of that of pure SP and dielectric loss can be 8 times of pure SP at power frequency. Dielectric constants of the composites all increased with various contents of nano Ag. Two types of shallow traps (0.52eV and 0.62eV) with trap densities (1.2 × 1010/cm3 and 2.0 × 1011/cm3) are found in the composite, which differs from those of pure SP (0.58eV, 3.1 × 1010/cm3) significantly. Resistivity of the composite is much greater than that of pure SP under cryogenic temperature (77K), which might be treated as the result of Coulomb Blockade effect. From the view of dielectric physics, the different characteristic between the composite and pure SP was discussed and a new concept of nano metal/dielectric materials composite used for device surface protection was introduced.

Dong, Xiaobing; Yin, Yi; Jiang, Xiuchen

322

Insulating polymer concrete. [Perlite or glass nodule aggregates bound together with a polyester resin  

SciTech Connect

An insulating polymer concrete (IPC) composite has been developed under contract to the Gas Research Institute for possible use as a dike insulation material at Liquid Natural Gas (LNG) storage facilities. In the advent of an LNG spill into the impounding dike area, the boiloff rate of the LNG can be substantially reduced if the surfaces of the dike are insulated. This increased safety at the LNG facility will tend to reduce the hazardous explosive mixture with atmospheric air in the surrounding region. The dike insulation material must have a low thermal conductivity and be unaffected by environmental conditions. The IPC composites developed consist of perlite or glass nodule aggregates bound together as a closed cell structure with a polyester resin. In addition to low thermal conductivity and porosity, these composites have correspondingly high strengths and, therefore, can carry transient loads of workmen and maintenance equipment. Prefabricated IPC panels have been installed experimentally and at least one utility is currently considering a complete installation at its LNG facility. 4 references, 8 tables.

Fontana, J.J.

1984-04-01

323

Degradation of polyester polyurethane by a newly isolated soil bacterium, Bacillus subtilis strain MZA-75.  

PubMed

A polyurethane (PU) degrading bacterial strain MZA-75 was isolated from soil through enrichment technique. The bacterium was identified through 16S rRNA gene sequencing, the phylogenetic analysis indicated the strain MZA-75 belonged to genus Bacillus having maximum similarity with Bacillus subtilis strain JBE0016. The degradation of PU films by strain MZA-75 in mineral salt medium (MSM) was analyzed by scanning electron microscopy (SEM), fourier transform infra-red spectroscopy (FT-IR) and gel permeation chromatography (GPC). SEM revealed the appearance of widespread cracks on the surface. FTIR spectrum showed decrease in ester functional group. Increase in polydispersity index was observed in GPC, which indicates chain scission as a result of microbial treatment. CO2 evolution and cell growth increased when PU was used as carbon source in MSM in Sturm test. Increase in both cell associated and extracellular esterases was observed in the presence of PU indicated by p-Nitrophenyl acetate (pNPA) hydrolysis assay. Analysis of cell free supernatant by gas chromatography-mass spectrometry (GC-MS) revealed that 1,4-butanediol and adipic acid monomers were produced. Bacillus subtilis strain MZA-75 can degrade the soft segment of polyester polyurethane, unfortunately no information about the fate of hard segment could be obtained. Growth of strain MZA-75 in the presence of these metabolites indicated mineralization of ester hydrolysis products into CO2 and H2O. PMID:23536219

Shah, Ziaullah; Krumholz, Lee; Aktas, Deniz Fulya; Hasan, Fariha; Khattak, Mutiullah; Shah, Aamer Ali

2013-11-01

324

Evaluation of biodegradable polyester-co-lactone microparticles for protein delivery.  

PubMed

Abstract Poly(glycerol adipate-co-?-pentadecalactone) (PGA-co-PDL) was previously evaluated for the colloidal delivery of ?-chymotrypsin. In this article, the effect of varying polymer molecular weight (MW) and chemistry on particle size and morphology; encapsulation efficiency; in vitro release; and the biological activity of ?-chymotrypsin (?-CH) and lysozyme (LS) were investigated. Microparticles were prepared using emulsion solvent evaporation and evaluated by various methods. Altering the MW or monomer ratio of PGA-co-PDL did not significantly affect the encapsulation efficiency and overall poly(1,3-propanediol adipate-co-?-pentadecalactone) (PPA-co-PDL) demonstrated the highest encapsulation efficiency. In vitro release varied between polymers, and the burst release for ?-CH-loaded microparticles was lower when a higher MW PGA-co-PDL or more hydrophobic PPA-co-PDL was used. The results suggest that, although these co-polyesters could be useful for protein delivery, little difference was observed between the different PGA-co-PDL polymers and PPA-co-PDL generally provided a higher encapsulation and slower release of enzyme than the other polymers tested. PMID:23855737

Tawfeek, Hesham M; Khidr, Sayed H; Samy, Eman M; Ahmed, Sayed M; Gaskell, Elsie E; Hutcheon, Gillian A

2014-09-01

325

Development of Composite Porous Scaffolds Based on Collagen and Biodegradable Poly(ester urethane)urea  

PubMed Central

Our objective in this work was to develop a flexible, biodegradable scaffold for cell transplantation that would incorporate a synthetic component for strength and flexibility and type I collagen for enzymatic lability and cytocompatibility. A biodegradable poly(ester urethane)urea was synthesized from poly(caprolactone), 1,4-diisocyanatobutane, and putrescine. Using a thermally induced phase separation process, porous scaffolds were created from a mixture containing this polyurethane and 0%, 10%, 20%, or 30% type I collagen. The resulting scaffolds were found to have open, interconnected pores (from 7 to >100 um) and porosities from 58% to 86% depending on the polyurethane/collagen ratio. The scaffolds were also flexible with breaking strains of 82–443% and tensile strengths of 0.97–4.11 MPa depending on preparation conditions. Scaffold degradation was significantly increased when collagenase was introduced into an incubating buffer in a manner that was dependent on the mass fraction of collagen present in the scaffold. Mass losses could be varied from 15% to 59% over 8 weeks. When culturing umbilical artery smooth muscle cells on these scaffolds higher cell numbers were observed over a 4-week culture period in scaffolds containing collagen. In summary, a strong and flexible scaffold system has been developed that can degrade by both hydrolysis and collagenase degradation pathways, as well as support cell growth. This scaffold possesses properties that would make it attractive for future use in soft tissue applications where such mechanical and biological features would be advantageous. PMID:16826792

Guan, Jianjun; Stankus, John J.; Wagner, William R.

2010-01-01

326

Subchronic inhalation toxicity study of a water-dispersible polyester in rats.  

PubMed

AQ55 is a high molecular weight, water-dispersible, amorphous polyester used in applications where the exclusion of solvents and conventional surfactants is desirable, such as water-based adhesives, coatings, emulsions, paint primers, cosmetics and detergents. Potential health effects were evaluated in rats exposed by inhalation for about 13 wk to mean concentrations of 0, 2.4, 19.6 or 199 mg/m3 AQ55 polymer. No mortality occurred and body weights were unaffected. Mean relative liver weights in all treated male groups were slightly higher than control weights, but were not judged to be treatment related. Absolute liver weights and all other organ weights except lung weights were normal. Haematology, clinical chemistries and gross pathology were unremarkable. Exposure-related changes in the 199 mg/m3 groups included increased mean absolute and relative lung weights, accumulations of macrophages and acute inflammatory cells in alveolar and bronchial lumina, and increased numbers of macrophages in sinusoids of peribronchial lymph nodes. Minor accumulation of macrophages in alveolar lumina was the only exposure-related change in the 19.6 mg/m3 group. No exposure-related effects were seen in the 2.4 mg/m3 group. AQ55 produced no systemic toxicity, and aerosols of AQ55 do not appear to be toxic to pulmonary tissues following subchronic inhalation exposure. PMID:9463537

Katz, G V; Faber, W D; Bernard, L G; Moulton, R A; David, R M; Vlaovic, M S; Dyer, W M

1997-01-01

327

The Influence of impact on Composite Armour System Kevlar-29/polyester-Al2O3  

NASA Astrophysics Data System (ADS)

An experimental investigation of high velocity impact responses of composite laminated plates using a helium gas gun has been presented in this paper. The aim of this study was to develop the novel composite structure that meets the specific requirements of ballistic resistance which used for body protections, vehicles and other applications. Thus the high velocity impact tests were performed on composite Kevlar-29 fiber/polyester resin with alumina powder (Al2O3). The impact test was conducted by using a cylindrical steel projectile of 7.62mm diameter at a velocity range of 160-400 m/s. The results (shown in this work) are in terms of varying plate thickness and the amount of energy absorbed by the laminated plates meanwhile we obtained that the 12mm thickness of composite plate suitable for impact loading up to 200m/s impact velocity. Therefore this composite structure (it is used to reduce the amount of Kevlar) considered most economical armoure products. We used the ANSYS AUTODYN 3D- v.12 software for our simulations. The results have been obtained a4.1% maximum errors with experimental work of energy absorption.

Ramadhan, A. A.; Abu Talib, A. R.; Mohd Rafie, A. S.; Zahari, R.

2012-09-01

328

Co-precipitation of protein and polyester as a method to isolate high molecular weight DNA.  

PubMed

DNA isolation is often the limiting step in genetic analysis using PCR and automated fragment analysis due to low quality or purity of DNA, the need to determine and adjust DNA concentrations after isolation etc. Several protocols have been developed which are either safe and provide good quality DNA or hazardous and provide excellent quality DNA. In this brief communication I describe a new and rapid method of DNA isolation which employs the co-precipitation of protein and polyester, in the presence of acetone, to remove contaminating proteins from a lysed-tissue sample, thus leaving high quality pure DNA. The advantages of this method are increased safety over the phenol:chloroform and the chaotrophic salt methods and increased purity over the salting-out method. Since the concentrations of DNA isolated using this method are relatively consistent regardless of the amount of starting tissue (within limits), adjustments of the DNA concentrations before use as templates in PCR's are not necessary. PMID:16970607

Dixson, Jamie D

2005-02-01

329

Grafting printing of cellulose fabric with the reactive disperse dyes containing N-substituted 3-chloro-2-hydroxypropyl group.  

PubMed

The printed cellulose and its blend materials have wide applications in many high-tech fields. Six new reactive disperse dyes (D1-D6) containing a 3-chloro-2-hydroxypropyl group based on epichlorohydrin were designed and synthesized. The electronic absorption spectra and their grafting printing property for cotton fabrics were investigated. The grafting mechanism on cotton fabric was also discussed. The results show that these dyes had larger bathochromic shifts in stronger polar solvent, dimethylformamide, than in the weaker polar solvents, acetonitrile and acetone. 3-Chloro-2-hydroxypropyl functional group of the dyes could form covalent bond with the hydroxyl group on cellulose by a nucleophilic substituted reaction. The good color yields of D1-D6 on printed cotton fabric were obtained by curing at 170-180 °C. The reactive disperse dyes for printing cellulose fabric had good building up and better printing property. The light fastness, rubbing fastness and fastness to perspiration of the printed fabric were good. The reactive disperse dyes have potential application in cleaner production of printing cotton and cotton/polyester blend fabrics. PMID:25256461

Li, Min; Zhang, Kai; Xie, Kongliang

2014-11-26

330

Electron Beam Freeform Fabrication  

NASA Video Gallery

Electron Beam Freeform Fabrication (EBF3) is a process by which NASA hopes to build metal parts in zero gravity environments. It's a layer-additive process that uses an electron beam and a solid wi...

331

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...

332

Biologically inspired digital fabrication  

E-print Network

Objects and systems in nature are models for the practice of sustainable design and fabrication. From trees to bones, natural systems are characterized by the constant interplay of creation, environmental response, and ...

Han, Sarah (Sarah J.)

2013-01-01

333

Nuclear Fabrication Consortium  

SciTech Connect

This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) � Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : � Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. � Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. � Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. � Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. � Supporting industry in helping to create a larger qualified nuclear supplier network. � Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. � Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. � Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium projects. Full technical reports for each of the projects have been submitted as well.

Levesque, Stephen

2013-04-05

334

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

335

Contribution To Degradation Study, Behavior Of Unsaturated Polyester Resin Under Neutron Irradiation  

SciTech Connect

Applications of unsaturated polyester thermosetting resins are numerous in construction sector, in transport, electric spare parts manufactures, consumer goods, and anticorrosive materials. This survey reports the effect of thermosetting polymer degradation (unsaturated polyester): degradation by neutrons irradiation. In order to evaluate the deterioration of our material, some comparative characterizations have been done between standard samples and damaged ones. Scanning electron microscopy (SEM), ultrasonic scanning, hardness test (Shore D) are the techniques which have been used. The exposure to a neutrons flux is carried out in the column of the nuclear research reactor of Draria (Algiers-Algeria). The energetic profile of the incidental fluxes is constituted of fast neutrons (PHI{sub R} = 3.10{sup 12} n.cm{sup -2}.s{sup -1}, E = 2 Mev) of thermal neutrons (PHI{sub TH} = 10{sup 13} n.cm{sup -2}.s{sup -1}; E = 0.025 ev) and epithermal neutrons (PHI{sub epi} = 7.10{sup 11} n.cm{sup -2}.s{sup -1}; E>4,9 ev). The received dose flow is 0,4 Kgy. We notice only a few scientific investigations can be found in this field. In comparison with the standard sample (no exposed) it is shown that the damage degree is an increasing process with the exposure. Concerning the description of irradiation effects on polymers, we can advance that several reactions are in competition: reticulation, chain break, and oxidation by radical mechanism. In our case the incidental particle of high energy fast neutrons whose energy is greater or equal to 2 Mev, is braked by the target with a nuclear shock during which the incidental particle transmits a part of its energy to an atom. If the energy transfer is sufficient, the nuclear shock permits to drive out an atom of its site the latter will return positioning interstitially, the energy that we used oversteps probably the energy threshold (displacement energy). This fast neutrons collision with target cores proceeds to an indirect ionization by the preliminary creation of excited secondary species that will generate ionization. Scanning electron microscopy (SEM) performed with an acceleration tension of 0,7 kV shows clearly the caused damage. This observation seems to indicate the presence of major chain breaks for the sample bombarded during 90 minutes. Let us note that the presence of benzenic cores improves behavior toward radiations indeed the chemical function recognized as the most stable to radiations is the aromatic ring. In order to value the rigidity of our material we have determined the Young's modulus . The values are 7.17, 7.60, 8.39 and 8.96 Gpa respectively for blank samples, 30, 60 and 90 minutes exposure ones. Thus, we remark an increase of Young's modulus that can be interpreted in terms of reticulation, provided to use the level of irradiation dose.

Abellache, D.; Lounis, A.; Taiebi, K. [Laboratory of Sciences and Material Engineering, Faculty of Mechanical Engineering and Chemical Engineering. U.S.T.H.B, BP32 El Alia, Algiers (Algeria)

2010-01-05

336

Effects of Porous Polystyrene Resin Parameters on Candida antarctica Lipase B Adsorption, Distribution, and Polyester Synthesis Activity  

SciTech Connect

Polystyrene resins with varied particle sizes (35 to 350-600 {mu}m) and pore diameters (300-1000 {angstrom}) were employed to study the effects of immobilization resin particle size and pore diameter on Candida antarctica Lipase B (CALB) loading, distribution within resins, fraction of active sites, and catalytic properties for polyester synthesis. CALB adsorbed rapidly (saturation time {<=}4 min) for particle sizes 120 {mu}m (pore size = 300 {angstrom}). Infrared microspectroscopy showed that CALB forms protein loading fronts regardless of resin particle size at similar enzyme loadings ({approx}8%). From the IR images, the fractions of total surface area available to the enzyme are 21, 33, 35, 37, and 88% for particle sizes 350-600, 120, 75, 35 {mu}m (pore size 300 {angstrom}), and 35 {mu}m (pore size 1000 {angstrom}), respectively. Titration with methyl p-nitrophenyl n-hexylphosphate (MNPHP) showed that the fraction of active CALB molecules adsorbed onto resins was {approx}60%. The fraction of active CALB molecules was invariable as a function of resin particle and pore size. At {approx}8% (w/w) CALB loading, by increasing the immobilization support pore diameter from 300 to 1000 {angstrom}, the turnover frequency (TOF) of {var_epsilon}-caprolactone ({var_epsilon}-CL) to polyester increased from 12.4 to 28.2 s{sup -1}. However, the {var_epsilon}-CL conversion rate was not influenced by changes in resin particle size. Similar trends were observed for condensation polymerizations between 1,8-octanediol and adipic acid. The results herein are compared to those obtained with a similar series of methyl methacrylate resins, where variations in particle size largely affected CALB distribution within resins and catalyst activity for polyester synthesis.

Chen,B.; Miller, M.; Gross, R.

2007-01-01

337

Encapsulation of docetaxel in oily core polyester nanocapsules intended for breast cancer therapy  

PubMed Central

This study is designed to test the hypothesis that docetaxel [Doc] containing oily core nanocapsules [NCs] could be successfully prepared with a high percentage encapsulation efficiency [EE%] and high drug loading. The oily core NCs were generated according to the emulsion solvent diffusion method using neutral Labrafac CC and poly(d, l-lactide) [PLA] as oily core and shell, respectively. The engineered NCs were characterized for particle mean diameter, zeta potential, EE%, drug release kinetics, morphology, crystallinity, and cytotoxicity on the SUM 225 breast cancer cell line by dynamic light scattering, high performance liquid chromatography, electron microscopies, powder X-ray diffraction, and lactate dehydrogenase bioassay. Typically, the formation of Doc-loaded, oily core, polyester-based NCs was evidenced by spherical nanometric particles (115 to 582 nm) with a low polydispersity index (< 0.05), high EE% (65% to 93%), high drug loading (up to 68.3%), and a smooth surface. Powder X-ray diffraction analysis revealed that Doc was not present in a crystalline state because it was dissolved within the NCs' oily core and the PLA shell. The drug/polymer interaction has been indeed thermodynamically explained using the Flory-Huggins interaction parameters. Doc release kinetic data over 144 h fitted very well with the Higuchi model (R2 > 0.93), indicating that drug release occurred mainly by controlled diffusion. At the highest drug concentration (5 ?M), the Doc-loaded oily core NCs (as a reservoir nanosystem) enhanced the native drug cytotoxicity. These data suggest that the oily core NCs are promising templates for controlled delivery of poorly water soluble chemotherapeutic agents, such as Doc. PMID:22168815

2011-01-01

338

Development and Evaluation of Novel Coupling Agents for Kenaf-Fiber-Reinforced Unsaturated Polyester Composites  

NASA Astrophysics Data System (ADS)

Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a 40% market share of all the thermoset composites. This widespread application is due to many favorable characteristics including low cost, ease of cure at room temperature, ease of molding, a good balance of mechanical, electrical and chemical properties. One of the barriers for the full utilization of the kenaf fiber reinforced UPE composites, however, is the poor interfacial adhesion between the natural fibers and the UPE resins. The good interfacial adhesion between kenaf fibers and UPE matrix is essential for generating the desired properties of kenaf-UPE composites for most of the end applications. Use of a coupling agent is one of the most effective ways of improving the interfacial adhesion. In this study, six novel effective coupling agents were developed and investigated for kenaf-UPE composites: DIH-HEA, MFA, NMA, AESO-DIH, AESO-MDI, and AESO-PMDI. All the coupling agents were able to improve the interfacial adhesion between kanaf and UPE resins. The coupling agents were found to significantly enhance the flexural properties and water resistance of the kenaf-UPE composites. Fourier transform infrared spectroscopy (FTIR) confirmed all the coupling agents were covalently bonded onto kenaf fibers. Scanning electron microscopy (SEM) images of the composites revealed the improved interfacial adhesion between kanaf fibers and UPE resins.

Ren, Xiaofeng

339

Solution-processed Ag-doped ZnO nanowires grown on flexible polyester for nanogenerator applications  

NASA Astrophysics Data System (ADS)

The integration of ZnO nanowire-based energy harvesting devices into flexible polyesters or clothes would have a significant effect on the energy harvesting building block for harvesting the mechanical energy from human motions. Moreover, the demonstration of high output power via a doping process opens an important method for enhancing the output power. Here, we report solution-based synthesis of Ag-doped ZnO nanowires on flexible polyester substrates without using any high temperature annealing processes. Along with the structural and optical characteristics of the Ag-doped ZnO nanowires, we demonstrate the efficient features of Ag-doped nanogenerators through the measurement of a sound-driven piezoelectric energy device with an output power of 0.5 ?W, which is nearly 2.9 times that of a nanogenerator with un-doped ZnO NWs. This finding could provide the possibility of high output nanogenerators for practical applications in future portable/wearable personal displays and motion sensors.The integration of ZnO nanowire-based energy harvesting devices into flexible polyesters or clothes would have a significant effect on the energy harvesting building block for harvesting the mechanical energy from human motions. Moreover, the demonstration of high output power via a doping process opens an important method for enhancing the output power. Here, we report solution-based synthesis of Ag-doped ZnO nanowires on flexible polyester substrates without using any high temperature annealing processes. Along with the structural and optical characteristics of the Ag-doped ZnO nanowires, we demonstrate the efficient features of Ag-doped nanogenerators through the measurement of a sound-driven piezoelectric energy device with an output power of 0.5 ?W, which is nearly 2.9 times that of a nanogenerator with un-doped ZnO NWs. This finding could provide the possibility of high output nanogenerators for practical applications in future portable/wearable personal displays and motion sensors. Electronic supplementary information (ESI) available: Additional SEM images, PL data, and rectifying circuits for SPENG. See DOI: 10.1039/c3nr03402j

Lee, Sanghyo; Lee, Junseok; Ko, Wonbae; Cha, Seungnam; Sohn, Junginn; Kim, Jongmin; Park, Jaegun; Park, Youngjun; Hong, Jinpyo

2013-09-01

340

Tensile and Adhesion Properties of Metal Thin Films Deposited onto Polyester Film Substrate Prepared by a Conventional Vacuum Evaporator  

NASA Astrophysics Data System (ADS)

Four kinds of metal, such as aluminum, copper, indium and tin, thin films were deposited onto polyester (PET) substrate by a conventional vacuum evaporator and evaluated their tensile and adhesion properties. The tensile property was estimated by observations of micro-cracks of the thin films due to the tensile test at 150°C. The tensile property of the metal thin films seems to relate with Brinell hardness and thickness of the thin film. The adhesion property of these metal thin films was estimated by measuring the pull strength. Aluminum thin film showed highest pull strength of all the thin films, and the pull strength increased with increase of the thickness.

Kita, Takuya; Saitoh, Shou; Iwamori, Satoru

341

Selection of materials for ventricular assist pump development and fabrication.  

PubMed

A study was undertaken to select 2 of the most promising bladder materials from a list of 8 carefully chosen polymers. The polymers chosen for testing included a wide spectrum of urethanes, as well as a polyester resin and a millable polyolefin rubber. The following materials were studied: Adiprene LW-500, Avcothane 51, Biomer, Hexsyn, Hytrel 4055, Mobay 240313, Pellethane 2103-80 AE, and Tecoflex HR. The selection process was based on a test matrix which was divided into segmented steps, each a logical sequel from its predecessor, and each of increasing technical complexity. Hydrolytic stability, flexure endurance, fabricability, tissue compatibility, hemocompatibility and chronic tissue compatibility were evaluated, forming the basis for the acceptance/rejection criteria. As a result of this search, 2 biomaterials were identified as most suitable for use in conventionally flocked bladders; Biomer and Tecoflex HR. Both Biomer and Tecoflex HR bladders have demonstrated impressive results in circulatory analog loop endurance tests, with Tecoflex bladders surpassing 50 million flexes to date, and Biomer bladders (the longest running bladders) exceeding 150 million flexes. Tests are continuing. PMID:910324

Szycher, M; Poirier, V; Keiser, J

1977-01-01

342

Fabrication of Bi-2223 high temperature superconducting magnet  

NASA Astrophysics Data System (ADS)

Bi-2223/Ag alloy multifilamentary tape, whose size was 0.21 mm in thickness, 3.14 mm in width and 400 m in length, was wound to 18 pancake coils to fabricate the high temperature superconducting magnet. Each single coil had an inner diameter of 50 mm and an outer diameter of 95 mm, and consumed about 20 m long superconducting tapes coated with 10 ?m thick polyester paint for insulation. The 18 pancake coils were stacked on a polyflon cylinder and the joints between each pancake coil were welded by tin solder and the copper current leads to the magnet as well. A couple of yokes had been added to the two sides of the magnet windings to decrease the radial magnetic flux density and therefore increase the Ic of the superconducting tapes. The maximum magnetic field reached 0.176 T while the Ic of the magnet was 8.16 A in the nitrogen liquid. The I- V curve, the B- I curve and the magnetic field space distribution of the magnet was tested.

Huang, H.; Wang, Y.; Zhang, P. P.; Han, Z. H.; Guo, S. Q.; Liu, M. L.; Liu, S. L.; Gu, C.

2003-04-01

343

Delamination of woven E-glass fabric composites  

SciTech Connect

An experimental/analytical study investigating delamination growth in E-glass fabric/polyester composites has been carried out. Double cantilever beam and end-notched flexure delamination specimens were tested and the measured data was compared to calculated results. A stacked shell finite element methodology has been developed to perform the analysis. This approach breaks the composite into sublaminate shells connected by springs spanning the delamination plane. The stacked shell analyses can use either a critical stress or a critical energy release rate criterion to propagate the delamination, and both criteria are shown to yield similar predictions. Role of connecting springs, and proper choice for spring constants has also been investigated in detail. The spring constants must be chosen in a physically meaningful way to develop consistent values of energy release rate, compliance, and the stress distribution ahead of the delamination. Calculated results for the double cantilever beam and end-notched flexure specimens are in good agreement with measured test data and continuum finite element solutions.

Dunn, M.L. [Colorado Univ., Boulder, CO (United States). Dept. of Mechanical Engineering; Reedy, E.D. Jr.; Guess, T.R. [Sandia National Labs., Albuquerque, NM (United States)

1993-11-01

344

Microfluidic channel fabrication method  

DOEpatents

A new channel structure for microfluidic systems and process for fabricating this structure. In contrast to the conventional practice of fabricating fluid channels as trenches or grooves in a substrate, fluid channels are fabricated as thin walled raised structures on a substrate. Microfluidic devices produced in accordance with the invention are a hybrid assembly generally consisting of three layers: 1) a substrate that can or cannot be an electrical insulator; 2) a middle layer, that is an electrically conducting material and preferably silicon, forms the channel walls whose height defines the channel height, joined to and extending from the substrate; and 3) a top layer, joined to the top of the channels, that forms a cover for the channels. The channels can be defined by photolithographic techniques and are produced by etching away the material around the channel walls.

Arnold, Don W. (Livermore, CA); Schoeniger, Joseph S. (Oakland, CA); Cardinale, Gregory F. (Oakland, CA)

2001-01-01

345

Fabric filter system study  

NASA Astrophysics Data System (ADS)

Results of the fourth year of operation of a fabric filter installed on a coal-fired boiler are reported. Project work during the fourth year concentrated on fabric studies. The 10-oz/sq yd fabrics of the 150 1/2 warp, 150 2/2T fill construction demonstrated superior performance over the most common 14-oz/sq yd constructions, regardless of coating. It was determined that improving cleaning by increasing shaking amplitude is more detrimental to baglife than increasing shaker frequency. Maintenance and operation observations continued, and the resolution of these types of problems became more efficient because of increased experience of maintenance personnel with baghouse-related problems.

Chambers, R. L.; Plunk, O. C.; Kunka, S. L.

1984-08-01

346

Other Fabric Structures  

NASA Technical Reports Server (NTRS)

There are two kinds of fabric structures - tension, supported by cables and pylons, and those supported by air pressure within an enclosed fabric envelope. They are becoming increasingly popular with architects, engineers, etc., because of their aesthetic appeal, low cost and maintenance, energy efficiency and good space utilization. The Structo-Fab roof weighs only 1/30 as much as a conventional roof of that size. Giant fans are used to blow air into the envelope between the roof's outer membrane and its inner liner automatically maintaining the pressure differential necessary for roof rigidity.

1985-01-01

347

In Situ Fabrication Technologies  

NASA Technical Reports Server (NTRS)

A manufacturing system is described that is internal to controlled cabin environments which will produce functional parts to net shape with sufficient tolerance, strength and integrity to meet application specific needs such as CEV ECLS components, robotic arm or rover components, EVA suit items, unforeseen tools, conformal repair patches, and habitat fittings among others. Except for start-up and shut-down, fabrication will be automatic without crew intervention under nominal scenarios. Off-nominal scenarios may require crew and/or Earth control intervention. System will have the ability to fabricate using both provisioned feedstock materials and feedstock refined from in situ regolith.

Rolin, Terry D.; Hammond, Monica

2005-01-01

348

Drum drying of fabrics  

SciTech Connect

A study of drying of textile fabrics on a drum heated by natural gas burner is presented. In the first stage of study, the distribution of the heat flux over the outer surface of the drum is calculated by an analytical method. In the second stage, this heat flux is entered in a numerical code able to simulate the heat and mass transfers in porous media. The simulation results validate the analytical model assumptions. Special attention is paid to the contact resistance between the drum and the fabric.

Stemmelen, D.; Moyne, C. [LEMTA, Vandoeuvre (France); Perre, R. [ENGREF, Nancy (France); Lebois, P. [CERUG Gaz de France, La Plaine St. Denis (France)

1997-10-01

349

MOX Fabrication Isolation Considerations  

SciTech Connect

This document provides a technical position on the preferred level of isolation to fabricate demonstration quantities of mixed oxide transmutation fuels. The Advanced Fuel Cycle Initiative should design and construct automated glovebox fabrication lines for this purpose. This level of isolation adequately protects the health and safety of workers and the general public for all mixed oxide (and other transmutation fuel) manufacturing efforts while retaining flexibility, allowing parallel development and setup, and minimizing capital expense. The basis regulations, issues, and advantages/disadvantages of five potential forms of isolation are summarized here as justification for selection of the preferred technical position.

Eric L. Shaber; Bradley J Schrader

2005-08-01

350

A blanket design, apparatus, and fabrication techniques for the mass production of multilayer insulation blankets for the Superconducting Super Collider  

SciTech Connect

The multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) consists of full cryostat length assemblies of aluminized polyester film fabricated in the form of blankets and installed as blankets to the 4.5K cold mass and the 20K and 80K thermal radiation shields. Approximately 40,000 MLI blankets will be required in the 10,000 cryogenic devices comprising the SSC accelerator. Each blanket is nearly 17 meters long and 1.8 meters wide. This paper reports the blanket design, an apparatus, and the fabrication method used to mass produce pre-fabricated MLI blankets. Incorporated in the blanket design are techniques which automate quality control during installation of the MLI blankets in the SSC cryostat. The apparatus and blanket fabrication method insure consistency in the mass produced blankets by providing positive control of the dimensional parameters which contribute to the thermal performance of the MLI blanket. By virtue of the fabrication process, the MLI blankets have inherent features of dimensional stability three-dimensional uniformity, controlled layer density, layer-to-layer registration, interlayer cleanliness, and interlayer material to accommodate thermal contraction differences. 11 refs., 6 figs., 1 tab.

Gonczy, J.D.; Boroski, W.N.; Niemann, R.C.; Otavka, J.G.; Ruschman, M.K.; Schoo, C.J.

1989-09-01

351

5-Fluorouracil-lipid conjugate: Potential candidate for drug delivery through encapsulation in hydrophobic polyester-based nanoparticles.  

PubMed

The encapsulation of 5-fluorouracil (5-FU) in hydrophobic polymeric materials is made feasible by a lipid-based prodrug approach. A lipid-5-FU conjugate of 5-FU with palmitic acid was synthesized in two-step process. A synthesized dipalmitoyl derivative (5-FUDIPAL) was characterized using Fourier transform infrared spectroscopy and (1)H-nuclear magnetic resonance. The 5-FUDIPAL was encapsulated in polyester-based polymers by the double emulsion-solvent evaporation method. The nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy and dynamic light scattering. The thermal stability was assessed by differential scanning calorimetry data. In vitro release kinetics measurements of the drug from nanoparticles showed the controlled release pattern over a period of time. Cytotoxicity measurements by MTT assay confirmed that dipalmitoyl derivative in nano formulation successfully inhibited the cell growth. Thus the combined physical and biological evaluation of the different polyester-based nanoparticle containing the modified drug showed a facile approach to delivering 5-FU to the tumour site with enhanced efficacy. PMID:25110286

Ashwanikumar, N; Kumar, Nisha Asok; Asha Nair, S; Vinod Kumar, G S

2014-11-01

352

Preparation of curcumin-loaded poly(ester amine) nanoparticles for the treatment of anti-angiogenesis.  

PubMed

The aim of this study was to prepare curcumin loaded poly(ester amine) nanoparticles and enhance their hydrophilicity and treatment efficacy on anti-angiogenesis zebra fish model. Poly(ester amine) (PEA) copolymer was synthesized in this study. The curcumin-loaded PEA nanoparticles were prepared through double emulsion-solvent evaporation technique. The average particle size of obtained nanoparticles was about 100 nm. The zeta potential of prepared nanoparticles was about 35.8+/-2.4 mV. Transmission electron microscopy demonstrated a narrow size distribution with in vitro release profile demonstrating in vitro slow release of curcumin from the PEA nanoparticles. The in vitro cytotoxicity of the curcumin encapsulated PEA nanoparticles nearly had the same tendency of cytotoxic activity in vitro with free curcumin on tumor cells. In vitro cellular uptake of the curcumin-loaded nanoparticles demonstrated in Hela cells demonstrated that this kind of nanoparticles can be a promising candidate as a drug delivery system to cancer cells. The Cur/PEA nanoparticles more efficiently inhibited angiogenesis (in vivo) in transgenic zebra fish model and Alginate-encapsulated tumor cells than free curcumin. No mortality or significant lesions were observed from histopathological study of the major organs. From our results, we can conclude that the prepared PEA nanoparticles are an efficient curcumin drug delivery system for anti-angiogenesis therapy. PMID:24734515

Ding, Qiuxia; Niu, Ting; Yang, Yi; Guo, Qingfa; Luo, Feng; Qian, Zhiyong

2014-04-01

353

Solution-processed Ag-doped ZnO nanowires grown on flexible polyester for nanogenerator applications.  

PubMed

The integration of ZnO nanowire-based energy harvesting devices into flexible polyesters or clothes would have a significant effect on the energy harvesting building block for harvesting the mechanical energy from human motions. Moreover, the demonstration of high output power via a doping process opens an important method for enhancing the output power. Here, we report solution-based synthesis of Ag-doped ZnO nanowires on flexible polyester substrates without using any high temperature annealing processes. Along with the structural and optical characteristics of the Ag-doped ZnO nanowires, we demonstrate the efficient features of Ag-doped nanogenerators through the measurement of a sound-driven piezoelectric energy device with an output power of 0.5 ?W, which is nearly 2.9 times that of a nanogenerator with un-doped ZnO NWs. This finding could provide the possibility of high output nanogenerators for practical applications in future portable/wearable personal displays and motion sensors. PMID:24056913

Lee, SangHyo; Lee, JunSeok; Ko, WonBae; Cha, SeungNam; Sohn, JungInn; Kim, JongMin; Park, JaeGun; Park, Youngjun; Hong, JinPyo

2013-10-21

354

Lithographic fabrication of nanoapertures  

DOEpatents

A new class of silicon-based lithographically defined nanoapertures and processes for their fabrication using conventional silicon microprocessing technology have been invented. The new ability to create and control such structures should significantly extend our ability to design and implement chemically selective devices and processes.

Fleming, James G. (Albuquerque, NM)

2003-01-01

355

DNA Microarray Fabrication  

NSDL National Science Digital Library

In this YouTube video, created by Southwest Center for Microsystems Education (SCME), viewers are introduced to the concept of DNA microarray fabrication. Specific topics include: non-contact printing process, photolithography process and maskless photolithography process. This is the third in a series of presentations on DNA microarrays. Supporting materials can be downloaded from the SCME website.

2014-07-03

356

Automated breeder fuel fabrication  

Microsoft Academic Search

The objective of the Secure Automated Fabrication (SAF) Project is to develop remotely operated equipment for the processing and manufacturing of breeder reactor fuel pins. The SAF line will be installed in the Fuels and Materials Examination Facility (FMEF). The FMEF is presently under construction at the Department of Energy's (DOE) Hanford site near Richland, Washington, and is operated by

L. H. Goldmann; J. R. Frederickson

1983-01-01

357

Fabric filters and baghouses  

Microsoft Academic Search

Companies planning construction or replacement of filtration equipment also can turn to consultants, bag makers and specialty conferences for more information. Or take advantage of a free fax service (302-999-4541) introduced to North America in late 1992 by Du Pont Co. of Wilmington, Del., a supplier of the fibers used in fabric filter bags. With specifics on operating conditions, the

Nudo

1993-01-01

358

Scheduling semiconductor wafer fabrication  

Microsoft Academic Search

The impact that scheduling can have on the performance of semi-conductor wafer fabrication facilities is assessed. The performance measure considered is the mean throughput time (sometimes called cycle time, turnaround time or manufacturing interval) for a lot of wafers. A variety of input control and sequencing rules are evaluated using a simulation model of a representative, but fictitious, semiconductor wafer

LAWRENCE M. WEIN

1988-01-01

359

Heat-Shrinkable, Seamless Fabric Tube  

NASA Technical Reports Server (NTRS)

Weaving produces generally tapered shape; heat-shrinking gives final shape. Tube woven in tapered shape from polyester yarn. Placed on heated mandrel. Heat shrinks fibers so sheath assumes shape of mandrel. Sheath coated with impermeable material. Useful on Earth for protective garments.

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

1988-01-01

360

Neurobehavioural changes and persistence of complaints in workers exposed to styrene in a polyester boat building plant: influence of exposure characteristics and microsomal epoxide hydrolase phenotype  

Microsoft Academic Search

OBJECTIVESTo investigate neurobehavioural effects and the persistence of complaints in workers exposed to styrene relative to exposure characteristics and the enzyme microsomal epoxide hydrolase (mEH) activity.METHODSA cross sectional study was performed in a retrospective cohort of workers of a polyester boat building plant 3 years after the main activity shut down in 1989. Workers still currently exposed to a much

M K Viaene; W Pauwels; H Veulemans; H A Roels; R Masschelein

2001-01-01

361

Evaluation of exp 14 C Labelled Solvents for Its Use in the E.R.A. Technique in the Case of Curing of Unsaturated Polyesters.  

National Technical Information Service (NTIS)

The Evaporative Rate Analysis (E.R.A.) technique was evaluated for the study of the curing of unsaturated polyesters as a function of time. Ethylene glycol monoethyl ether acetate exp 14 C was found to be a suitable solvent for this purpose. Determination...

M. L. Pisarello de Troparevsky, A. E. A. Mitta, A. Troparevsky

1978-01-01

362

ENVIRONMENTAL TECHNOLOGY VERIFICATION, TEST REPORT OF CONTROL OF BIOAEROSOLS IN HVAC SYSTEMS, FILTRATION GROUP, AEROSTAR "C-SERIES" POLYESTER PANEL FILTER  

EPA Science Inventory

The Environmental Technology Verification report discusses the technology and performance of the AeroStar "C-Series" Polyester Panel Filter air filter for dust and bioaerosol filtration manufactured by Filtration Group. The pressure drop across the filter was 126 Pa clean and 267...

363

Fabricating nanogaps by nanoskiving.  

PubMed

There are several methods of fabricating nanogaps with controlled spacings, but the precise control over the sub-nanometer spacing between two electrodes-and generating them in practical quantities-is still challenging. The preparation of nanogap electrodes using nanoskiving, which is a form of edge lithography, is a fast, simple and powerful technique. This method is an entirely mechanical process which does not include any photo- or electron-beam lithographic steps and does not require any special equipment or infrastructure such as clean rooms. Nanoskiving is used to fabricate electrically addressable nanogaps with control over all three dimensions; the smallest dimension of these structures is defined by the thickness of the sacrificial layer (Al or Ag) or self-assembled monolayers. These wires can be manually positioned by transporting them on drops of water and are directly electrically-addressable; no further lithography is required to connect them to an electrometer. PMID:23711512

Pourhossein, Parisa; Chiechi, Ryan C

2013-01-01

364

ITER dome fabrication processes  

Microsoft Academic Search

The 3\\/4-ton International Thermonuclear Experimental Reactor (ITER) divertor dome component is fabricated from three dissimilar metals-stainless steel, copper, and tungsten. It is actively cooled to withstand heat loads of 5 MW\\/m2 during nominal operation, transient beat loads of 15 MW\\/m2, for 1-2 seconds, and volumetric heating of 0.5-5 MW\\/m3. The divertor dome is comprised of two subcomponents: a 316L cast

G. W. Wille; D. E. Driemeyer; W. J. Chatterton; K. D. Foreman

1999-01-01

365

Fabrication of High T  

NASA Astrophysics Data System (ADS)

Metal-clad high-T_{rm c} superconductor wires have been fabricated by conventional hot extrusion and wire drawing techniques. The fabrication processes which were used influenced the microstructure which, in turn, governed the superconducting properties of metal-clad Y-Ba-Cu-O (YBCO) and Bi-Pb-Sr-Ca-Cu-O (BPSCCO) superconductors. The ability to form these materials into long thin wires and the electrical properties of the wires were assessed. Extruded metal-clad wire was fabricated by coextruding a Cu billet containing a Ag-clad superconductor core at 920^circC and 800 ^circC for YBCO and BPSCCO materials, respectively. The deformation behaviour of the composite billets was investigated by extruding through dies with semicone angle alpha = 30 ^circ and using a range of core diameters and reduction ratios. For combinations of initial core diameter and reduction ratio, domains of deformation behaviour were established including sound flow, nonuniform flow, core fracture and sleeve fracture. Hot extruded YBCO and BPSCCO superconductor had densities estimated to be between 95% and 98% of the theoretical values. The material contained transverse cracks except for a sample of YBCO which had an addition of 10 wt% Ag. The microstructure of the YBCO material consisted of YBa _2Cu_3O{_{7-x}}, while the BPSCCO material contained an intimate mixture of the high-T _{rm c} (Bi,Pb)_2 Sr_2Ca_2Cu _3O{_ {10-x}} (110 K) and low-T _{rm c} (Bi,Pb)_2 Sr_2Ca_1Cu _2O{_ {8-x}} (80 K) phases with Ca _2CuO_3 and Sr-Ca -Cu-O impurity particles. X-ray polefigure goniometry of extruded BPSCCO superconductor revealed that the material was relatively untextured. As-extruded YBCO and BPSCCO were semiconducting. Oxygen treated YBCO had a lower normal-state resistivity than the as-extruded material, and a superconducting transition above 77 K was not achieved. Heat treatment of extruded BPSCCO regenerated superconductivity above 77 K, with the transition behaviour dependent on the proportion of high -T_{rm c} and low -T_{rm c} phases in the microstructure. Single filament YBCO and BPSCCO wires was also fabricated by codrawing Ag tubes filled with superconductor powder. Downstream processing of the single filament wire was investigated and included intermediate sintering and redrawing, rolling of wire to form tape, coil fabrication and multifilament fabrication. The deformation and compaction behaviour of single filament wire was examined as a function of wire reduction. The mean particle size, shape and core density varied with total reduction and determine relative wall thinning or thickening behaviour of the cladding metal. Ag-clad BPSCCO tapes were formed by rolling single filament wire. The J_{rm c} of the wire increased markedly, up to 11,900 A.cm ^{-2}, owing to a combination of preferred orientation of the plate-like grains, high density, improved flux pinning and sintering in a partial pressure of oxygen of 0.05 atm. Multifilament wire containing between 7 and 2223 filaments were fabricated by codrawing bundles of single filament wire. (Abstract shortened by UMI.).

Apperley, Miles Hyam

1992-01-01

366

Effects of Surface Treatments on Mechanical Properties and Water Resistance of Kenaf Fiber-Reinforced Unsaturated Polyester Composites  

SciTech Connect

Effects of surface treatments on the strength and water resistance of kenaf fiber-reinforced unsaturated polyester (UPE) composites were investigated. A new coupling agent that consists of 1,6-diisocyanato-hexane (DIH) and 2-hydroxylethyl acrylate (HEA) was investigated for surface treatments of kenaf fibers. The surface treatments were found to significantly enhance the tensile strength, modulus of rupture, modulus of elasticity, and water resistance of the resulting kenaf UPE composites. Fourier transform infrared spectroscopy (FTIR) confirmed that DIH-HEA was covalently bonded onto kenaf fibers. Scanning electron microscopy (SEM) images of the composites revealed that chemical treatment of kenaf fibers with a combination of DIH and HEA improved the interfacial adhesion between kenaf fibers and UPE resin in the DIHHEA-treated kenafUPE composites. The mechanisms by which the chemical treatment of kenaf fiber surfaces improved strength and water resistance of the resulting kenaf UPE composites were discussed.

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

2012-05-17

367

Thermal performance measurements of a 100 percent polyester MLI (multilayer insulation) system for the Superconducting Super Collider  

SciTech Connect

The plastic materials used in the multilayer insulation (MLI) blankets of the superconducting magnets of the Superconducting Super Collider (SSC) are comprised entirely of polyesters. This paper reports on tests conducted in three separate experimental blanket arrangements. The tests explore the thermal performance of two candidate blanket joint configurations each employing a variation of a stepped-butted joint nested between sewn blanket seams. The results from the joint configurations are compared to measurements made describing the thermal performance of the basic blanket materials as tested in an ideal joint configuration. Twenty foil sensors were incorporated within each test blanket to measure interstitial layer and joint layer temperatures. Heat flux and thermal gradients are reported for high and degraded insulating vacuums, and during transient and steady state conditions. In complement with this paper is an associate paper bearing the same title head but with the title extension Part 1: Instrumentation and experimental preparation (300K-80K)'. 5 refs., 8 figs., 2 tabs.

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

1989-09-01

368

10,000 optical write, read, and erase cycles in an azobenzene sidechain liquid-crystalline polyester  

NASA Astrophysics Data System (ADS)

We show for what is believed to be the first time that it is possible to generate 10,000 rapid write, read, and erase cycles optically in an azobenzene sidechain liquid-crystalline polyester. We do this by exposing the film alternately to visible light from an argon laser at 488 nm and ultraviolet light from a krypton laser at 351 nm. The efficiency of the system shows several exponential decays, presumably associated with the azobenzene chromophores' aligning out of the plane of the film and the lifetime of the cis state of the azobenzene. A local temperature increase may also play a role. However, there is enough contrast even after 10,000 cycles to permit a clear distinction between the maximum and the minimum anisotropy. As the anisotropy is stable between erasures, this method could have immediate applications for optical storage.

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

1996-06-01

369

Gliding Resistance and Strength of a Braided Polyester/Monofilament Polyethylene Composite (FiberWire(R)) Suture in Human Flexor Digitorum Profundus Tendon Repair: An In-Vitro Biomechanical Study  

PubMed Central

Purpose While the strength of a tendon repair is clearly important, the friction of the repair is also a relevant consideration. The purpose of this study was to characterize the frictional coefficient, gliding resistance and breaking strength of suture materials and a suture construct commonly used for flexor tendon repair. Methods We measured the friction coefficients of 3-0 braided nylon enclosed in a smooth nylon outer shell (Supramid, S. Jackson, Alexandria, VA), 3-0 braided polyester coated with polybutilate (Ethibond, Ethicon, Somerville, NJ), and a 3-0 braided polyester/monofilament polyethylene composite (FiberWire, Arthrex, Naples, FL) sutures. We also measured the gliding resistance, linear breaking strength and resistance to gapping of zone 2 modified Pennington tendon repairs with the two lowest friction sutures in 20 human cadaveric flexor digitorum profundus (FDP) tendons. Results The braided polyester/monofilament polyethylene composite had a significantly lower friction coefficient (0.054) than either the coated polyester (0.076) or nylon (0.130) sutures (p<0.001). The gliding resistances of the repaired tendons with braided/monofilament polyethylene composite suture and coated, braided polyester were similar (p> 0.05). The strength of the two repairs, force to produce a 2mm gap, and resistance to gap formation than coated, braided polyester repairs were also not significantly different. Conclusion Braided polyester composite is a low friction suture material. However, when this suture was used for tendon repair with a locking suture technique, it did not show a significant effect on the gliding resistance and repair strength compared with the same repair using coated polyester suture. PMID:19121735

Silva, Jose M.; Zhao, Chunfeng; An, Kai-Nan; Zobitz, Mark E.; Amadio, Peter C.

2009-01-01

370

Mask fabrication process  

DOEpatents

A method for fabricating masks and reticles useful for projection lithography systems. An absorber layer is conventionally patterned using a pattern and etch process. Following the step of patterning, the entire surface of the remaining top patterning photoresist layer as well as that portion of an underlying protective photoresist layer where absorber material has been etched away is exposed to UV radiation. The UV-exposed regions of the protective photoresist layer and the top patterning photoresist layer are then removed by solution development, thereby eliminating the need for an oxygen plasma etch and strip and chances for damaging the surface of the substrate or coatings.

Cardinale, Gregory F. (Oakland, CA)

2000-01-01

371

Electrochemical fabrication of capacitors  

DOEpatents

A film of nickel oxide is anodically deposited on a graphite sheet held in osition on an electrochemical cell during application of a positive electrode voltage to the graphite sheet while exposed to an electrolytic nickel oxide solution within a volumetrically variable chamber of the cell. An angularly orientated x-ray beam is admitted into the cell for transmission through the deposited nickel oxide film in order to obtain structural information while the film is subject to electrochemical and in-situ x-ray spectroscopy from which optimum film thickness, may be determined by comparative analysis for capacitor fabrication purposes.

Mansour, Azzam N. (Fairfax Sta., VA); Melendres, Carlos A. (Lemont, IL)

1999-01-01

372

Fabrication of metal nanoshells  

NASA Technical Reports Server (NTRS)

Metal nanoshells are fabricated by admixing an aqueous solution of metal ions with an aqueous solution of apoferritin protein molecules, followed by admixing an aqueous solution containing an excess of an oxidizing agent for the metal ions. The apoferritin molecules serve as bio-templates for the formation of metal nanoshells, which form on and are bonded to the inside walls of the hollow cores of the individual apoferritin molecules. Control of the number of metal atoms which enter the hollow core of each individual apoferritin molecule provides a hollow metal nonparticle, or nanoshell, instead of a solid spherical metal nanoparticle.

Kim, Jae-Woo (Inventor); Choi, Sang H. (Inventor); Lillehei, Peter T. (Inventor); Chu, Sang-Hyon (Inventor); Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, Jr., James R. (Inventor)

2012-01-01

373

NCSX Vacuum Vessel Fabrication  

SciTech Connect

The National Compact Stellarator Experiment (NCSX) is being constructed at the Princeton Plasma Physics Laboratory (PPPL) in conjunction with the Oak Ridge National Laboratory (ORNL). The goal of this experiment is to develop a device which has the steady state properties of a traditional stellarator along with the high performance characteristics of a tokamak. A key element of this device is its highly shaped Inconel 625 vacuum vessel. This paper describes the manufacturing of the vessel. The vessel is being fabricated by Major Tool and Machine, Inc. (MTM) in three identical 120º vessel segments, corresponding to the three NCSX field periods, in order to accommodate assembly of the device. The port extensions are welded on, leak checked, cut off within 1" of the vessel surface at MTM and then reattached at PPPL, to accommodate assembly of the close-fitting modular coils that surround the vessel. The 120º vessel segments are formed by welding two 60º segments together. Each 60º segment is fabricated by welding ten press-formed panels together over a collapsible welding fixture which is needed to precisely position the panels. The vessel is joined at assembly by welding via custom machined 8" (20.3 cm) wide spacer "spool pieces." The vessel must have a total leak rate less than 5 X 10-6 t-l/s, magnetic permeability less than 1.02?, and its contours must be within 0.188" (4.76 mm). It is scheduled for completion in January 2006.

Viola, M. E.; Brown, T.; Heitzenroeder, P.; Malinowski, F.; Reiersen, W.; Sutton, L.; Goranson, P.; Nelson, B.; Cole, M.; Manuel, M.; McCorkle, D.

2005-10-07

374

Ceramic fabrication R D  

SciTech Connect

This project is separated into three tasks. The first task is a design and modeling effort to be carried out by MSE, Inc. The purpose of this task is to develop and analyze designs for various cohesive ceramic fabrication (CCF) components. This quarter, the advanced molybdenum disicilide MHD electrode design was essentially completed. Final refinements will be made after molybdenum disilicide processing results are available and the final layer compositions are established. Work involving whisker incorporation was initiated on the high stress component. It is unlikely that whiskers will become low cost, so particulate reinforcement will be pursued. Modeling work will resume once a suitable aluminum oxide/silicon carbide composition is selected that can be fired to acceptable densities by pressureless sintering. Task 2, subcontracted to Applied Technology Laboratories (ATL), is principally directed at establishing a property data base for monolithic and laminated alumina fabricated using the CCF process. This quarter, ATL demonstrated that the CCF process does not compromise the flexure strength of alumina. Task 3, subcontracted to Ceramics Binder Systems, Inc., focused on CCF silicon carbide particulate reinforced alumina and on the development of processing procedures for nonoxide molybdenum disilicide. Preliminary results indicate that achieving high densities in silicon carbide particulate reinforced aluminum oxide will be difficult. Molybdenum disilicide results are encouraging, and it is clear that the CCF process will work with this nonoxide material. 3 refs., 18 figs., 4 tabs.

Not Available

1990-01-01

375

Fabrication of zein nanostructure  

NASA Astrophysics Data System (ADS)

The concerns on the increase of polluting plastic wastes as well as the U.S. dependence on imported petrochemical products have driven an attention towards alternative biodegradable polymers from renewable resources. Zein protein, a co-product from ethanol production from corn, is a good candidate. This research project aims to increase zein value by adopting nanotechnology for fabricating advanced zein packaging films and zein microfluidic devices. Two nanotechnology approaches were focused: the polymer nanoclay nanocomposite technique where the nanocomposite structures were created in the zein matrix, and the soft lithography and the microfluidic devices where the micro and nanopatterns were created on the zein film surfaces. The polymer nanoclay nanocomposite technique was adopted in the commonly used zein film fabrication processes which were solvent casting and extrusion blowing methods. The two methods resulted in partially exfoliated nanocomposite structures. The impact of nanoclays on the physical properties of zein films strongly depended on the film preparation techniques. The impact of nanoclay concentration was more pronounced in the films made by extrusion blowing technique than by the solvent casting technique. As the processability limitation for the extrusion blowing technique of the zein sample containing hight nanoclay content, the effect of the nanoclay content on the rheological properties of zein hybrid resins at linear and nonlinear viscoelastic regions were further investigated. A pristine zein resin exhibited soft solid like behavior. On the other hand, the zein hybrid with nanoclay content greater than 5 wt.% showed more liquid like behavior, suggesting that the nanoclays interrupted the entangled zein network. There was good correspondence between the experimental data and the predictions of the Wagner model for the pristine zein resins. However, the model failed to predict the steady shear properties of the zein nanoclay nanocomposite resins. The soft lithography technique was mainly used to fabricate micro and nanostructures on zein films. Zein material well-replicated small structures with the smallest size at sub micrometer scale that resulted in interesting photonic properties. The bonding method was also developed for assembling portable zein microfluidic devices with small shape distortion. Zein-zein and zein-glass microfluidic devices demonstrated sufficient strength to facilitate fluid flow in a complex microfluidic design with no leakage. Aside from the fabrication technique development, several potential applications of this environmentally friendly microfluidic device were investigated. The concentration gradient manipulation of Rhodamine B solution in zein-glass microfluidic devices was demonstrated. The diffusion of small molecules such as fluorescent dye into the wall of the zein microfluidic channels was observed. However, with this formulation, zein microfluidic devices were not suitable for cell culture applications. This pioneer study covered a wide spectrum of the implementation of the two nanotechnology approaches to advance zein biomaterial which provided proof of fundamental concepts as well as presenting some limitations. The findings in this study can lead to several innovative research opportunities of advanced zein biomaterials with broad applications. The information from the study of zein nanocomposite structure allows the packaging industry to develop the low cost biodegradable materials with physical property improvement. The information from the study of the zein microfluidic devices allows agro-industry to develop the nanotechnology-enabled microfluidic sensors fabricated entirely from biodegradable polymer for on-site disease or contaminant detection in the fields of food and agriculture.

Luecha, Jarupat

376

Fabrication of three-dimensional microfluidic systems by stacking molded polydimethylsiloxane (PDMS) layers  

NASA Astrophysics Data System (ADS)

A new technique to fabricate 3D microchannels using polydimethylsiloxane (PDMS) elastomer material is presented. The process allows for the stacking of many thin (about 100 micrometers thick) patterned PDMS layers to realize complex 3D channel paths. Replica molding method is utilized to generate each layer. The master for each layer is formed on a silicon wafer using SU-8 positive relief photoresist. PDMS is cast against the master producing molded layers containing channels and openings. To realize thin layers with openings, a sandwich molding configuration was developed that allows precise control of the PDMS thickness. The master wafer is clamped within a sandwich that includes flat aluminum plates, a flexible polyester film layer, a rigid Pyrex wafer and a rubber sheet. A parametric study is performed on PDMS surface activation in a reactive ion etching (RIE) system and the subsequent methanol treatment for bonding and aligning very thin individual components to a substrate. Low RF power and short treatment times are better than high RF power and long treatment times respectively for instant bonding. Layer to layer alignment of less than 15 micrometers is achieved with manual alignment techniques that utilize surface tension driven self alignment methods. A coring procedure is used to realize off chip fluidic connections via the bottom PDMS layer, allowing the top layer to remain smooth and flat for complete optical access. After fabricating 3D channel paths, the hydrophobic surfaces of the inside channel walls can be activated (hydrophobic to hydrophilic) an oxygen plasma RIE system.

Jo, Byung-Ho; Beebe, David J.

1999-08-01

377

Preparation of water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups and their micelles behavior, anticoagulant effect and cytotoxicity.  

PubMed

Biocompatibility of nanoparticles has been attracting great interest in the development of nanoscience and nanotechnology. Herein, the aliphatic water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups (HBPE-SO3 NPs) were synthesized and characterized. They are amphiphilic polymeric nanoparticles with hydrophobic hyperbranched polyester (HBPE) core and hydrophilic sulfonic acid terminal groups. Based on our observations, we believe there are two forms of HBPE-SO3 NPs in water under different conditions: unimolecular micelles and large multimolecular micelles. The biocompatibility and anticoagulant effect of the HBPE-SO3 NPs were investigated using coagulation tests, hemolysis assay, morphological changes of red blood cells (RBCs), complement and platelet activation detection, and cytotoxicity (MTT). The results confirmed that the sulfonic acid terminal groups can substantially enhance the anticoagulant property of HBPE, and the HBPE-SO3 NPs have the potential to be used in nanomedicine due to their good bioproperties. PMID:23718279

Han, Qiaorong; Chen, Xiaohan; Niu, Yanlian; Zhao, Bo; Wang, Bingxiang; Mao, Chun; Chen, Libin; Shen, Jian

2013-07-01

378

AFIP-4 Fabrication Summary Report  

SciTech Connect

The AFIP-4 (ATR Full –size-plate In center flux trap Position) experiment was designed to evaluate the performance of monolithic fuels at a scale prototypic of research reactor fuel plates. Twelve qualified fueled plates were fabricated for the AFIP-4 experiment; to be irradiated in the INL Advanced Test Reactor (ATR). This report provides details of the fuel fabrication efforts; including material selection, fabrication processes, and fuel plate qualification.

Glenn A. Moore

2010-02-01

379

AFIP-6 Fabrication Summary Report  

SciTech Connect

The AFIP-6 (ATR Full-size plate In center flux trap Position) experiment was designed to evaluate the performance of monolithic fuels at a scale prototypic of research reactor fuel plates. Two qualified fueled plates were fabricated for the AFIP-6 experiment; to be irradiated in the INL Advanced Test Reactor (ATR). This report provides details of the fuel fabrication efforts, including material selection, fabrication processes, and fuel plate qualification.

Glenn A. Moore; M. Craig Marshall

2011-09-01

380

Structural correlation of unsaturated fatty acid esters through graphical comparison of gas-liquid chromatographic retention times on a polyester substrate  

Microsoft Academic Search

The correlation of structures of esters of certain unsaturated fatty acids is possible through a linear relation when logarithms\\u000a of retention time on polyester substrates are plotted against the number of carbon atoms in the fatty acid chain.\\u000a \\u000a This correlation is independent of any relation to the retention times of the esters of the saturated fatty acids, and depends\\u000a solely

R. G. Ackman

1963-01-01

381

New Skin Test for Detection of Bovine Tuberculosis on the Basis of Antigen-Displaying Polyester Inclusions Produced by Recombinant Escherichia coli  

PubMed Central

The tuberculin skin test for diagnosing tuberculosis (TB) in cattle lacks specificity if animals are sensitized to environmental mycobacteria, as some antigens in purified protein derivative (PPD) prepared from Mycobacterium bovis are present in nonpathogenic mycobacteria. Three immunodominant TB antigens, ESAT6, CFP10, and Rv3615c, are present in members of the pathogenic Mycobacterium tuberculosis complex but absent from the majority of environmental mycobacteria. These TB antigens have the potential to enhance skin test specificity. To increase their immunogenicity, these antigens were displayed on polyester beads by translationally fusing them to a polyhydroxyalkanoate (PHA) synthase which mediated formation of antigen-displaying inclusions in recombinant Escherichia coli. The most common form of these inclusions is poly(3-hydroxybutyric acid) (PHB). The respective fusion proteins displayed on these PHB inclusions (beads) were identified using tryptic peptide fingerprinting analysis in combination with matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). The surface exposure and accessibility of antigens were assessed by enzyme-linked immunosorbent assay (ELISA). Polyester beads displaying all three TB antigens showed greater reactivity with TB antigen-specific antibody than did beads displaying only one TB antigen. This was neither due to cross-reactivity of antibodies with the other two antigens nor due to differences in protein expression levels between beads displaying single or three TB antigens. The triple-antigen-displaying polyester beads were used for skin testing of cattle and detected all cattle experimentally infected with M. bovis with no false-positive reactions observed in those sensitized to environmental mycobacteria. The results suggested applicability of TB antigen-displaying polyester inclusions as diagnostic reagents for distinguishing TB-infected from noninfected animals. PMID:24532066

Chen, Shuxiong; Parlane, Natalie A.; Lee, Jason; Wedlock, D. Neil; Buddle, Bryce M.

2014-01-01

382

Duration of repellency of N,N-diethyl-3-methylbenzamide, citronella oil and cypermethrin against Culicoides species when applied to polyester mesh  

Microsoft Academic Search

The repellent efficacy of 15% N,N-diethyl-3-methylbenzamide (DEET), 0.6% citronella oil, and 0.3% ?-cyano-cypermethrin against Culicoides species was compared in three 5×5 Latin squares (15 replicates) under South African field conditions. DEET, citronella oil or ?-cyano-cypermethrin were applied to polyester meshes that were fitted to down-draught suction 220V UV light traps which were operated overnight. No significant repellent effect against Culicoides

P. C. Page; K. Labuschagne; J. P. Nurton; G. J. Venter; A. J. Guthrie

2009-01-01

383

The effect of alkalization and fibre alignment on the mechanical and thermal properties of kenaf and hemp bast fibre composites: Part 1 – polyester resin matrix  

Microsoft Academic Search

Long and random hemp and kenaf fibres were used in the as-received condition and alkalized with a 0.06 M NaOH solution. They were combined with polyester resin and hot-pressed to form natural fibre composites. The mechanical properties of the composites were measured to observe the effect of fibre alignment and alkalization. A general trend was observed whereby alkalized and long

Sharifah H. Aziz; Martin P. Ansell

2004-01-01

384

Use of Rifampin-Soaked Gelatin-Sealed Polyester Grafts for in Situ Treatment of Primary Aortic and Vascular Prosthetic Infections  

Microsoft Academic Search

Background. In situ treatment of artery\\/graft infection has distinct advantages compared to vessel excision and extra-anatomic bypass procedures. Based on animal studies of a rifampin-soaked, gelatin-impregnated polyester graft that demonstrated prolonged in vivo antibacterial activity, this antibiotic-bonded graft was used selectively in patients for in situ treatment of low-grade Gram-positive prosthetic graft infections or primary aortic infections not amenable to

Dennis F. Bandyk; Michael L. Novotney; Brad L. Johnson; Martin R. Back; Steven R. Roth

2001-01-01

385

The first peripherally masked thiol dendrimers: a facile and highly efficient functionalization strategy of polyester dendrimers via one-pot xanthate deprotection/thiol-acrylate Michael addition reactions.  

PubMed

Introducing multiple reactive functional groups at the periphery of dendrimer materials presents considerable challenges if the functionality is able to self-react. An efficient and facile approach to introducing masked thiols at the surface of polyester dendrimers is presented. One-pot, deprotection/thiol-acrylate Michael addition from the xanthate-functional dendritic substrates (generation zero to two) has been achieved for the first time, with high efficiency demonstrated using three acrylates of varying chemistry and avoiding disulfide formation. PMID:24595823

Auty, Sam E R; Andrén, Oliver; Malkoch, Michael; Rannard, Steven P

2014-06-25

386

Protein fabrication automation  

PubMed Central

Facile “writing” of DNA fragments that encode entire gene sequences potentially has widespread applications in biological analysis and engineering. Rapid writing of open reading frames (ORFs) for expressed proteins could transform protein engineering and production for protein design, synthetic biology, and structural analysis. Here we present a process, protein fabrication automation (PFA), which facilitates the rapid de novo construction of any desired ORF from oligonucleotides with low effort, high speed, and little human interaction. PFA comprises software for sequence design, data management, and the generation of instruction sets for liquid-handling robotics, a liquid-handling robot, a robust PCR scheme for gene assembly from synthetic oligonucleotides, and a genetic selection system to enrich correctly assembled full-length synthetic ORFs. The process is robust and scalable. PMID:17242375

Cox, J. Colin; Lape, Janel; Sayed, Mahmood A.; Hellinga, Homme W.

2007-01-01

387

Assessment of the interrelation between photooxidation and biodegradation of selected polyesters after artificial weathering.  

PubMed

Three commercially available biodegradable polymers, two different aromatic-aliphatic copolyesters and polylactic acid, intended for the fabrication of agricultural mulching films, in addition to other applications, were subjected to a series of tests with the aim of studying the relationship between their photooxidation and biodegradation. Photooxidation resulted in the rearrangement of polymeric chains, in the case of both copolyesters the events led to polymeric chain crosslinking and the formation of insoluble polymeric gel. The tendency was significantly more pronounced for the copolyester with the higher content of the aromatic constituent. As regards polylactic acid photochemical reactions were not accompanied by crosslinking but instead provoked chain scissions. A biodegradation experiment showed that, despite marked structural changes, the extent of photooxidation was not the decisive factor, which significantly modified the rate of biodegradation in all three materials investigated. The specific surface area of the sample specimens was shown to be more important. PMID:22534201

Stloukal, Petr; Verney, Vincent; Commereuc, Sophie; Rychly, Josef; Matisova-Rychlá, Lyda; Pis, Vladimir; Koutny, Marek

2012-08-01

388

Synthesis, in vitro degradation, and mechanical properties of two-component poly(ester urethane)urea scaffolds: effects of water and polyol composition.  

PubMed

The development of minimally invasive therapeutics for orthopedic clinical conditions has substantial benefits, especially for osteoporotic fragility fractures and vertebral compression fractures. Poly(ester urethane)urea (PEUUR) foams are potentially useful for addressing these conditions because they cure in situ upon injection to form porous scaffolds. In this study, the effects of water concentration and polyester triol composition on the physicochemical, mechanical, and biological properties of PEUUR foams were investigated. A liquid resin (lysine diisocyanate) and hardener (poly(epsilon-caprolactone-co-glycolide-co-DL-lactide) triol, tertiary amine catalyst, anionic stabilizer, and fatty acid-derived pore opener) were mixed, and the resulting reactive liquid mixture was injected into a mold to harden. By varying the water content over the range of 0.5 to 2.75 parts per hundred parts polyol, materials with porosities ranging from 89.1 to 95.8 vol-% were prepared. Cells permeated the PEUUR foams after 21 days post-seeding, implying that the pores are open and interconnected. In vitro, the materials yielded non-cytotoxic decomposition products, and differences in the half-life of the polyester triol component translated to differences in the PEUUR foam degradation rates. We anticipate that PEUUR foams will present compelling opportunities for the design of new tissue-engineered scaffolds and delivery systems because of their favorable biological and physical properties. PMID:17658992

Guelcher, Scott; Srinivasan, Abiraman; Hafeman, Andrea; Gallagher, Katie; Doctor, John; Khetan, Sudhir; McBride, Sean; Hollinger, Jeffrey

2007-09-01

389

Widely applicable coinage metal window electrodes on flexible polyester substrates applied to organic photovoltaics.  

PubMed

The fabrication, exceptional properties, and application of 8 nm thick Cu, Ag, Au, and Cu/Ag bilayer electrodes on flexible polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) substrates is reported. These electrodes are fabricated using a solvent free process in which the plastic surface is chemically modified with a molecular monolayer of thiol and amine terminated alkylsilanes prior to metal deposition. The resulting electrodes have a sheet resistance of ?14 ? sq?¹, are exceptionally robust and can be rapidly thermally annealed at 200 °C to reduce their sheet resistance to ?9 ? sq?¹. Notably, annealing Au electrodes briefly at 200 °C causes the surface to revert almost entirely to the {111} face, rendering it ideal as a model electrode for fundamental science and practical application alike. The power conversion efficiency of 1 cm² organic photovoltaics (OPVs) employing 8 nm Ag and Au films as the hole-extracting window electrode exhibit performance comparable to those on indium-tin oxide, with the advantage that they are resistant to repeated bending through a small radius of curvature and are chemically well-defined. OPVs employing Cu and bilayer Cu:Ag electrodes exhibit inferior performance due to a lower open-circuit voltage and fill factor. Measurements of the interfacial energetics made using the Kelvin probe technique provide insight into the physical reason for this difference. The results show how coinage metal electrodes offer a viable alternative to ITO on flexible substrates for OPVs and highlight the challenges associated with the use of Cu as an electrode material in this context. PMID:23127805

Stec, Helena M; Hatton, Ross A

2012-11-01

390

Polyester production by halophilic and halotolerant bacterial strains obtained from mangrove soil samples located in Northern Vietnam.  

PubMed

This research article reports halophilic and halotolerant bacteria isolated from mangrove forests located in Northern Vietnam. Several of these bacteria were able to synthesize polyhydroxyalkanoates (PHAs). PHAs are polyesters stored by microorganisms under the presence of considerable amounts of a carbon source and deficiency of other essential nutrient such as nitrogen or phosphorous. Mangrove forests in Northern Vietnam are saline coastal habitats that have not been microbiologically studied. Mangrove ecosystems are, in general, rich in organic matter, but deficient in nutrients such as nitrogen and phosphorus. We have found about 100 microorganisms that have adapted to mangrove forests by accumulating PHAs. The production of polyesters might therefore be an integral part of the carbon cycle in mangrove forests. Three of the strains (ND153, ND97, and QN194) isolated from the Vietnamese forests were identified as Bacillus species, while other five strains (QN187, ND199, ND218, ND240, and QN271) were phylogenetically close related to the ?-proteobacterium Yangia pacifica. These strains were found to accumulate PHAs in noticeable amounts. Polymer inclusions and chemical structure were studied by transmission electron microscopy and proton nuclear magnetic resonance (NMR) spectroscopy analyses, respectively. Strains ND153, ND97, QN194, QN187, ND240, and QN271 synthesized poly(3-hydroxybutyrate) (PHB) from glucose, whereas strains ND199 and ND218 synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from this carbohydrate. With the exception of strain QN194, the strains accumulated PHBV when a combination of glucose and propionate was included in the culture medium. The polymer yields and cell growth reached by one Bacillus isolate, strain ND153, and one Gram-negative bacterium, strain QN271, were high and worth to be researched further. For experiments performed in shake flasks, strain ND153 reached a maximum PHBV yield of 71 wt% and a cell dry weight (CDW) of 3.6 g/L while strain QN271 attained a maximum PHB yield of 48 wt% and a CDW of 5.1 g/L. Both strain ND153 and strain QN271 may only represent a case in point that exemplifies of the potential that mangrove forests possess for the discovery of novel halophilic and halotolerant microorganisms able to synthesize different types of biopolyesters. PMID:23233461

Van-Thuoc, Doan; Huu-Phong, Tran; Thi-Binh, Nguyen; Thi-Tho, Nguyen; Minh-Lam, Duong; Quillaguamán, Jorge

2012-12-01

391

Decomposition of 1,4-dioxane by photo-Fenton oxidation coupled with activated sludge in a polyester manufacturing process.  

PubMed

The cyclic ether 1,4-dioxane is a synthetic industrial chemical that is used as a solvent in producing paints and lacquers. The EPA and the International Agency for Research on Cancer(IARC) classified 1,4-dioxane as a GROUP B2(probable human) carcinogen. 1,4-dioxane is also produced as a by-product during the manufacture of polyester. In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, Korea was investigated regarding the release of high concentrations of 1,4-dioxane (about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2010). A 10 ton/day pilot-scale treatment system using photo-Fenton oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2800 ppm H(2)O(2) and 1,400 ppm FeSO(4) were maintained along with 10 UV-C lamps (240 microW/cm(2)) installed and operated continuously during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L where TOC concentration in the effluent had been moreover increased due to decomposed products such as aldehydes and organic acids. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane and their by-products (i.e., TOC). As a result, 1,4-dioxane in the effluent has been decreased as low as 0.5 mg/L. The optimal conditions for the activated sludge process that were obtained are as follows: DO, 3-3.5 mg/L; HRT, 24 h; SRT 15 d; MLSS, 3,000 mg/L. Consequently, photo-Fenton oxidation coupled with activated sludge can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard. PMID:19273900

So, M H; Han, J S; Han, T H; Seo, J W; Kim, C G

2009-01-01

392

Polyester production by halophilic and halotolerant bacterial strains obtained from mangrove soil samples located in Northern Vietnam  

PubMed Central

This research article reports halophilic and halotolerant bacteria isolated from mangrove forests located in Northern Vietnam. Several of these bacteria were able to synthesize polyhydroxyalkanoates (PHAs). PHAs are polyesters stored by microorganisms under the presence of considerable amounts of a carbon source and deficiency of other essential nutrient such as nitrogen or phosphorous. Mangrove forests in Northern Vietnam are saline coastal habitats that have not been microbiologically studied. Mangrove ecosystems are, in general, rich in organic matter, but deficient in nutrients such as nitrogen and phosphorus. We have found about 100 microorganisms that have adapted to mangrove forests by accumulating PHAs. The production of polyesters might therefore be an integral part of the carbon cycle in mangrove forests. Three of the strains (ND153, ND97, and QN194) isolated from the Vietnamese forests were identified as Bacillus species, while other five strains (QN187, ND199, ND218, ND240, and QN271) were phylogenetically close related to the ?-proteobacterium Yangia pacifica. These strains were found to accumulate PHAs in noticeable amounts. Polymer inclusions and chemical structure were studied by transmission electron microscopy and proton nuclear magnetic resonance (NMR) spectroscopy analyses, respectively. Strains ND153, ND97, QN194, QN187, ND240, and QN271 synthesized poly(3-hydroxybutyrate) (PHB) from glucose, whereas strains ND199 and ND218 synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from this carbohydrate. With the exception of strain QN194, the strains accumulated PHBV when a combination of glucose and propionate was included in the culture medium. The polymer yields and cell growth reached by one Bacillus isolate, strain ND153, and one Gram-negative bacterium, strain QN271, were high and worth to be researched further. For experiments performed in shake flasks, strain ND153 reached a maximum PHBV yield of 71 wt% and a cell dry weight (CDW) of 3.6 g/L while strain QN271 attained a maximum PHB yield of 48 wt% and a CDW of 5.1 g/L. Both strain ND153 and strain QN271 may only represent a case in point that exemplifies of the potential that mangrove forests possess for the discovery of novel halophilic and halotolerant microorganisms able to synthesize different types of biopolyesters. PMID:23233461

Van-Thuoc, Doan; Huu-Phong, Tran; Thi-Binh, Nguyen; Thi-Tho, Nguyen; Minh-Lam, Duong; Quillaguaman, Jorge

2012-01-01

393

Three-dimensional tissue fabrication  

Microsoft Academic Search

In recent years, advances in fabrication technologies have brought a new dimension to the field of tissue engineering. Using manufacturing-based methods and hydrogel chemistries, researchers have been able to fabricate tissue engineering scaffolds with complex 3-D architectures and customized chemistries that mimic the in vivo tissue environment. These techniques may be useful in developing therapies for replacing lost tissue function,

Valerie Liu Tsang; Sangeeta N. Bhatia

2004-01-01

394

A reflux tube fabric radiator  

Microsoft Academic Search

An alternative heat rejection system is possible that will meet survivability criteria while greatly enhancing space nuclear power systems. This alternative radiator design, the reflux tube fabric radiator, uses light weight high strength fabric materials, relies on an induced artificial gravity, and builds on the long established technologies associated with reflux tubes and thermosyphons, the predecessors of the modern microgravity

Edmund P. Coomes; Joseph M. Kelly

1988-01-01

395

Process for fabrication of cermets  

DOEpatents

Cermet comprising ceramic and metal components and a molten metal infiltration method and process for fabrication thereof. The light weight cermets having improved porosity, strength, durability, toughness, elasticity fabricated from presintered ceramic powder infiltrated with a molten metal or metal alloy. Alumina titanium cermets biocompatible with the human body suitable for bone and joint replacements.

Landingham, Richard L. (Livermore, CA)

2011-02-01

396

Fabrication technologies for terahertz waveguide  

Microsoft Academic Search

Terahertz waveguide components can now be realised using a variety of methods. The size and geometry of waveguide at terahertz frequencies ideally lends itself to fabrication via a number of micromachining techniques. The use of micromachining allows the realisation of waveguide components that cannot be fabricated via conventional machining at these frequencies. Conventional machining should not, however, be overlooked. Corrugated

Chris M. Mann

1998-01-01

397

CW RFQ fabrication and engineering  

Microsoft Academic Search

The design and fabrication of a four-vane RFQ to deliver a 100 mA CW proton beam at 6.7 MeV is described. This linac is an Oxygen-Free Electrolytic (OFE) copper structure 8 m in length and was fabricated using hydrogen furnace brazing as the joining technology.

D. Schrage; L. Young; P. Roybal

1998-01-01

398

Laser modification of polyamide fabrics  

NASA Astrophysics Data System (ADS)

A new method for the modification of the properties of polyamide fabric, based on exposure to the output from a CO 2 laser, has been investigated. It was found that, after laser modification of polyamide fabric, the dyeability of fabric was increased significantly, while the bursting strength was decreased. The reasons for this drastic increase in dyeability of polyamide fabrics have been analyzed with the help of FTIR and iodine sorption methods, revealing a relationship with a decrease in the crystallinity of the polyamide. It was observed that, as the laser modification of the fabric was carried out with low intensity, the concentration of free amino groups, which are necessary during dyeing with acid and reactive dyes, increased.

Bahtiyari, M. ?.

2011-02-01

399

A comparison of the use of vacuum metal deposition versus cyanoacrylate fuming for visualisation of fingermarks and grab impressions on fabrics.  

PubMed

Both vacuum metal deposition (VMD) and cyanoacrylate fuming (CAF) are techniques used to visualise latent fingermarks on smooth non-porous surfaces such as plastic and glass. VMD was initially investigated in the 1970s as to its effectiveness for visualising prints on fabrics, but was abandoned when radioactive sulphur dioxide was found to be more effective. However, interest in VMD was resurrected in the 1990s when CAF was also used routinely. We now report on studies to determine whether VMD or CAF is the more effective technique for the detection of marks on fabrics. Four different fabrics, nylon, polyester, polycotton and cotton, were utilised during this study, along with 15 donors who ranged in their age and ability to leave fingermarks, from good to medium to poor, thus reflecting the general population. Once samples were collected they were kept for a determined time (1, 2, 3, 4, 5, 6, 7, 14, 21 or 28 days) and then treated using either the gold and zinc metal VMD process or standard cyanoacrylate fuming. The smoother fabrics, such as nylon, consistently produced greater ridge detail whereas duller fabrics, like cotton tended only to show empty prints and impressions of where the fabric had been touched, rather than any ridge details. The majority of fabrics did however allow the development of touch marks that could be targeted for DNA taping which potentially could lead to a DNA profile. Of the two techniques VMD was around 5 times more effective than CAF, producing a greater amount of ridge detail, palmar flexion creases and target areas on more samples and fabrics. PMID:24630323

Fraser, Joanna; Deacon, Paul; Bleay, Stephen; Bremner, David H

2014-03-01

400

Sensory interaction and descriptions of fabric hand.  

PubMed

82 subjects who viewed and felt fabrics (sensory interaction group) used different categories of terms to describe fabric hand than did 38 subjects who only felt the fabrics. Therefore, the methods used to measure fabric hand that isolate the senses may not accurately assess the way in which subjects describe fabric hand in nonlaboratory settings. PMID:8532445

Burns, L D; Chandler, J; Brown, D M; Cameron, B; Dallas, M J

1995-08-01

401

Fabric parameter mapping for seam sewability  

Microsoft Academic Search

A technique has been developed to examine the relationships between fabric parameters by comparing both the fabric mechanical properties and physical characteristics of the material. Similarities between fabric parameters are also identified and analysed. The fabrics were tested using the FAST system and an electronic fingerprint chart was produced for each fabric. Computer software was created to automatically analyse the

J. McLoughlin; T. Sabir; S. Hayes

2010-01-01

402

Space fabrication demonstration system composite beam cap fabricator  

NASA Technical Reports Server (NTRS)

A detailed design for a prototype, composite beam cap fabricator was established. Inputs to this design included functional tests and system operating requirements. All required materials were procured, detail parts were fabricated, and one composite beam cap forming machine was assembled. The machine was demonstrated as a stand-alone system. Two 12-foot-long beam cap members were fabricated from laminates graphite/polysulfane or an equivalent material. One of these members, which as structurally tested in axial compression, failed at 490 pounds.

1982-01-01

403

Biodegradable poly(ester urethane)urea elastomers with variable amino content for subsequent functionalization with phosphorylcholine.  

PubMed

While surface modification is well suited for imparting biomaterials with specific functionality for favorable cell interactions, the modification of degradable polymers would be expected to provide only temporary benefit. Bulk modification by incorporating pendant reactive groups for subsequent functionalization of biodegradable polymers would provide a more enduring approach. Towards this end, a series of biodegradable poly(ester urethane)urea elastomers with variable amino content (PEUU-NH2 polymers) were developed. Carboxylated phosphorycholine was synthesized and conjugated to the PEUU-NH2 polymers for subsequent bulk functionalization to generate PEUU-PC polymers. Synthesis was verified by proton nuclear magnetic resonance, X-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The impact of amine incorporation and phosphorylcholine conjugation was shown on mechanical, thermal and degradation properties. Water absorption increased with increasing amine content, and further with PC conjugation. In wet conditions, tensile strength and initial modulus generally decreased with increasing hydrophilicity, but remained in the range of 5-30MPa and 10-20MPa, respectively. PC conjugation was associated with significantly reduced platelet adhesion in blood contact testing and the inhibition of rat vascular smooth muscle cell proliferation. These biodegradable PEUU-PC elastomers offer attractive properties for applications as non-thrombogenic, biodegradable coatings and for blood-contacting scaffold applications. Further, the PEUU-NH2 base polymers offer the potential to have multiple types of biofunctional groups conjugated onto the backbone to address a variety of design objectives. PMID:25132273

Fang, Jun; Ye, Sang-Ho; Shankarraman, Venkat; Huang, Yixian; Mo, Xiumei; Wagner, William R

2014-11-01

404

Synthesis of poly(ethylene furandicarboxylate) polyester using monomers derived from renewable resources: thermal behavior comparison with PET and PEN.  

PubMed

Poly(ethylene-2,5-furandicarboxylate) (PEF) is a new alipharomatic polyester that can be prepared from monomers derived from renewable resources like furfural and hydroxymethylfurfural. For this reason it has gained high interest recently. In the present work it was synthesized from the dimethylester of 2,5-furandicarboxylic acid and ethylene glycol by applying the two-stage melt polycondensation method. The thermal behavior of PEF was studied in comparison to its terephthalate and naphthalate homologues poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN), which were also synthesized following the same procedure. The equilibrium melting point of PEF was found to be 265 °C while the heat of fusion for the pure crystalline PEF was estimated to be about 137 J g(-1). The crystallization kinetics was analyzed using various models. PET showed faster crystallization rates than PEN and this in turn showed faster crystallization than PEF, under both isothermal and non-isothermal conditions. The spherulitic morphology of PEF during isothermal crystallization was investigated by polarized light microscopy (PLM). A large nucleation density and a small spherulite size were observed for PEF even at low supercoolings, in contrast to PET or PEN. Thermogravimetric analysis indicated that PEF is thermally stable up to 325 °C and the temperature for the maximum degradation rate was 438 °C. These values were a little lower than those for PET or PEN. PMID:24647534

Papageorgiou, George Z; Tsanaktsis, Vasilios; Bikiaris, Dimitrios N

2014-05-01

405

Polyester-idarubicin nanoparticles and a polymer-photosensitizer complex as potential drug formulations for cell-mediated drug delivery.  

PubMed

Cell-mediated transport of therapeutics has emerged as promising alternative to classical drug delivery approaches. To preserve viability and functions of carrier cells, encapsulation of active drugs in protective nanoparticles or the use of inducible therapeutics has been proposed. Here, we compared the effects of novel polymeric formulations of an active and a stimulus-sensitive anti-cancer drug on human T lymphocytes to identify suitable drug preparations for cell-mediated drug delivery. For the first approach, the chemotherapeutic agent idarubicin (IDA) was encapsulated in poly(lactic-co-glycolic-acid) (PLGA) and newly developed maleate-polyester (MPE) nanoparticles. PLGA- and MPE-encapsulated IDA was efficiently internalized by ex vivo activated human T lymphocytes; however, both encapsulations could not prevent premature T cell death resulting from IDA-uptake. In contrast, loading with a poly(styrene sulfonate) (PSS)-complex of the light-sensitive pharmaceutical 5,10,15,20-tetrakis(meso-hydroxyphenyl)porphyrin (mTHPP) did not affect T cell viability if upon loading the cells were kept in the dark. The photosensitizer was transferred from loaded T lymphocytes to co-cultivated carcinoma cells, and induced cancer cell death if co-cultures were exposed to light. Inducible drugs, such as photosensitizers, thus, may help to overcome the limitations of encapsulated active drugs and open up new perspectives for the use of cells as drug transporters in cancer therapy. PMID:25089507

Blaudszun, André-R; Lian, Qiong; Schnabel, Melanie; Loretz, Brigitta; Steinfeld, Ute; Lee, Hyeck-H; Wenz, Gerhard; Lehr, Claus-M; Schneider, Marc; Philippi, Anja

2014-10-20

406

Silicone-coated non-woven polyester dressing enhances reepithelialisation in a sheep model of dermal wounds.  

PubMed

Negative-pressure wound therapy (NPWT) also known as V.A.C. (Vacuum-assisted closure), is widely used to manage various type of wounds and accelerate healing. NPWT has so far been delivered mainly via open-cell polyurethane (PU) foam or medical gauze. In this study an experimental setup of sheep wound model was used to evaluate, under NPWT conditions, the performance of a silicone-coated non-woven polyester (N-WPE) compared with PU foam and cotton hydrophilic gauze, used as reference materials. Animals were anesthetized with spontaneous breathing to create three 3 × 3 cm skin defects bilaterally; each animal received three different samples on each side (n = 6 in each experimental group) and was subjected to negative and continuous 125 mmHg pressure up to 16 days. Wound conditions after 1, 8 and 16 days of treatment with the wound dressings were evaluated based on gross and histological appearances. Skin defects treated with the silicone-coated N-WPE showed a significant decrease in wound size, an increase of re-epithelialization, collagen deposition and wound neovascularisation, and a minimal stickiness to the wound tissue, in comparison with gauze and PU foam. Taken all together these findings indicate that the silicone-coated N-WPE dressing enhances wound healing since stimulates higher granulation tissue formation and causes minor tissue trauma during dressing changes. PMID:22692367

Losi, Paola; Briganti, Enrica; Costa, Manolo; Sanguinetti, Elena; Soldani, Giorgio

2012-09-01

407

Synthesis and characterization of novel organosoluble and optically active aromatic polyesters containing L-methionine and phthalimide pendent groups.  

PubMed

5-(4-Methylthio-2-phthalimidylbutanoylamino)isophthalic acid (5) as a novel diacid monomer containing phthalimide and flexible chiral groups was prepared by dehydration of L: -methionine and phthalic anhydride followed by reacting with thionyl chloride and then treating with 5-aminoisophthalic acid (5AIPA) in dry N,N-dimethylacetamide (DMAc). A series of novel polyesters (PEs) containing phthalimide group was prepared by the reaction of diacid monomer 5 with several aromatic diols via direct polyesterification with tosyl chloride/pyridine/dimethylformamide (DMF) system as condensing agent. The resulting new polymers were obtained in good yields and inherent viscosities ranging between 0.21 and 0.51 dLg(-1) were characterized with FT-IR, 1H NMR, elemental and thermogravimetric analysis techniques. These polymers are readily soluble in polar organic solvents such as DMAc, DMF, dimethyl sulfoxide and protic solvents such as sulfuric acid. Specific rotation experiments demonstrate the optical activity induction due to successful insertion of L-methionine in the structure of pendent groups. Thermogravimetric analysis showed that the 10% weight loss temperature in a nitrogen atmosphere were more than 315 degrees C, which indicates that the resulting PEs have good thermal stability. PMID:18060345

Mallakpour, Shadpour; Seyedjamali, Hojjat

2008-05-01

408

Biodegradable poly(ester urethane) urea scaffolds for tissue engineering: Interaction with osteoblast-like MG-63 cells.  

PubMed

Porous three-dimensional scaffolds with potential for application as cancellous bone graft substitutes were prepared from aliphatic segmented poly(ester urethane) urea using the phase-inverse technique. Proton nuclear magnetic resonance, size-exclusion chromatography, electron spectroscopy for chemical analysis, secondary ion mass spectrometry, infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, computed tomography and mechanical tests were carried out, to characterize the scaffolds' physicochemical properties. Human osteosarcoma MG-63 cells were seeded into the scaffolds for 1, 2, 3 and 4weeks to evaluate their potential to support attachment, growth and proliferation of osteogenic cells. The scaffold-cell interaction was assessed by analysis of DNA content, total protein amount, alkaline phosphatase activity and WST-1 assay. The scaffolds supported cell attachment, growth and proliferation over the whole culture period of 4weeks (DNA, total protein amount). There was, however, a reduction in the WST-1 assay values at 4weeks, which might suggest a reduction in the rate of cell proliferation at this time. PMID:24560622

Podporska-Carroll, Joanna; Ip, Josephine W Y; Gogolewski, Sylwester

2014-06-01

409

Influence of Cow Bone Particle Size Distribution on the Mechanical Properties of Cow Bone-Reinforced Polyester Composites  

PubMed Central

This work was carried out to investigate the influence of cow bone particle size distribution on the mechanical properties of polyester matrix composites in order to consider the suitability of the materials as biomaterials. Cow bone was procured from an abattoir, washed with water, and sun-dried for 4 weeks after which it was crushed with a sledge hammer and was further pulverized with laboratory ball mill. Sieve size analysis was carried out on the pulverized bone where it was sieved into three different sizes of 75, 106, and 300??m sieve sizes. Composite materials were developed by casting them into tensile and flexural tests moulds using predetermined proportions of 2, 4, 6, and 8%. The samples after curing were striped from the moulds and were allowed to be further cured at room temperature for 3 weeks before tensile and flexural tests were performed on them. Both tensile and flexural strength were highly enhanced by 8 wt% from 75??m while toughness was highly enhanced by 6 and 8?wt% from 300??m. This shows that fine particles lead to improved strength while coarse particles lead to improved toughness. The results show that these materials are structurally compatible and are being developed from animal fibre based particle; it is expected to also aid the compatibility with the surface conditions as biomaterials. PMID:24324892

Oladele, Isiaka Oluwole; Adewole, Temitope Akinyemi

2013-01-01

410

Singlet and triplet emission from methylenediphenyl-diisocyanate-based poly(ester urethane): determination of the energy-level diagram  

NASA Astrophysics Data System (ADS)

Optical absorption and luminescence measurements have been made on 4,4'-methylenediphenyl 1,1'-diisocyanate (MDI)-based poly(ester urethane) (PESU) and model compounds diphenylmethane (DPM) and butanol-capped MDI. Phosphorescence spectra of the three samples are nearly identical with maxima at 527, 488, 451, and 422 nm. However, onset of strong optical absorption near 300 nm in PESU and MDI precludes observation of the corresponding fluorescence spectrum. In contrast, DPM exhibits weaker absorption with onset occurring near 270 nm. Consequently, its fluorescence spectrum is revealed and characterized by maxima at 302, 294, 286, and 279 nm. From these data we derive the energy-level diagram for PESU and show that phosphorescence is due to electronic transitions between the first excited triplet and singlet ground states (T 1?S 0), whereas fluorescence transitions occur between both first and second excited singlet and ground states (S 1?S 0, and S 2?S 0). The experimentally derived values are in good agreement with previously published theoretical values for the electronic excited states of PESU.

Cooke, D. W.; Muenchausen, R. E.; Bennett, B. L.; Wrobleski, D. A.; Orler, E. B.

2003-02-01

411

Influence of cow bone particle size distribution on the mechanical properties of cow bone-reinforced polyester composites.  

PubMed

This work was carried out to investigate the influence of cow bone particle size distribution on the mechanical properties of polyester matrix composites in order to consider the suitability of the materials as biomaterials. Cow bone was procured from an abattoir, washed with water, and sun-dried for 4 weeks after which it was crushed with a sledge hammer and was further pulverized with laboratory ball mill. Sieve size analysis was carried out on the pulverized bone where it was sieved into three different sizes of 75, 106, and 300??m sieve sizes. Composite materials were developed by casting them into tensile and flexural tests moulds using predetermined proportions of 2, 4, 6, and 8%. The samples after curing were striped from the moulds and were allowed to be further cured at room temperature for 3 weeks before tensile and flexural tests were performed on them. Both tensile and flexural strength were highly enhanced by 8 wt% from 75??m while toughness was highly enhanced by 6 and 8?wt% from 300??m. This shows that fine particles lead to improved strength while coarse particles lead to improved toughness. The results show that these materials are structurally compatible and are being developed from animal fibre based particle; it is expected to also aid the compatibility with the surface conditions as biomaterials. PMID:24324892

Oladele, Isiaka Oluwole; Adewole, Temitope Akinyemi

2013-01-01

412

Thermal performance measurements of a 100 percent polyester MLI (multilayer insulation) system for the Superconducting Super Collider  

SciTech Connect

Thermal performance measurements of a 100 percent polyester multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) were conducted in a Heat Leak Test Facility (HLTF) under three experimental test arrangements. Each experiment measured the thermal performance of a 32-layer MLI blanket instrumented with twenty foil sensors to measure interstitial layer temperatures. Heat leak values and sensor temperatures were monitored during transient and steady state conditions under both design and degraded insulating vacuums. Heat leak values were measured using a heatmeter. MLI interstitial layer temperatures were measured using Cryogenic Linear Temperature Sensors (CLTS). Platinum resistors monitored system temperatures. High vacuum was measured using ion gauges; degraded vacuum employed thermocouple gauges. A four-wire system monitored instrumentation sensors and calibration heaters. An on-line computerized data acquisition system recorded and processes data. This paper reports on the instrumentation and experimental preparation used in carrying out these measurements. In complement with this paper is an associate paper bearing the same title head, but with the title extension Part 2: Laboratory results (300K--80K). 13 refs., 7 figs.

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

1989-09-01

413

Environmentally Benign Flame Retardant Nanocoatings for Fabric  

E-print Network

percent PSP coating after burning. In several instances, a direct flame on the fabric was extinguished. The peak HRR and THR of coated fabric has 30 percent and 65 percent reduction, respectively, compared to the uncoated control fabric. These anti...

Li, Yu-Chin

2012-07-16

414

Fabricating Copper Nanotubes by Electrodeposition  

NASA Technical Reports Server (NTRS)

Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

2009-01-01

415

Fabrication of silicon optical fiber  

NASA Astrophysics Data System (ADS)

We experimentally demonstrate the fabrication of silicon optical fibers by using the powder-in-tube technique. The fibers are drawn from a preform utilizing a custom-made fiber drawing system. Silicon optical fibers having cladding diameters in the range of 40 to 240 ?m, core diameters in the range of 10 to 100 ?m, and an approximate overall length of 7 cm have been fabricated. The powder-in-tube technique is versatile and can be utilized to fabricate fibers with different dimensions and core/cladding materials.

Scott, Brian; Wang, Ke; Caluori, Vincent; Pickrell, Gary

2009-10-01

416

Quantitative Fabric of Consolidated Kaolinite.  

National Technical Information Service (NTIS)

Structure is the combination of the geometrical arrangement of particles and the forces operating between them. The geometrical arrangement of particles and associated voids is called fabric and is the component of structure that is most amenable to measu...

R. T. Martin

1965-01-01

417

Reasonable computing for architectural fabrication  

E-print Network

The use of digital fabrication tools in the architecture industry serve a particular group of individuals whose familiarity of the tools are by trade skill. Machines lack the understanding of people in its ability to ...

Villalon, Rachelle B. (Rachelle Bentajado)

2008-01-01

418

Digital materials for digital fabrication  

E-print Network

This thesis introduces digital materials by analogy with digital computation and digital communications. Traditional fabrication techniques include pick-and-place, roll-to-roll, molding, patterning and more. Current research ...

Popescu, George A

2007-01-01

419

Fabrice Valle Directeur par intrim  

E-print Network

internationales P�le allocation et gestion de ressources Isabelle Sohler Assistante Daria Lamy Assistante Secr plateau de Saclay et Orsay Danielle Dowek Politique de sites Fabrice Vall�e Daria Lamy Assistante

van Tiggelen, Bart

420

Film Fabrication Technologies at NREL  

NASA Technical Reports Server (NTRS)

The National Renewable Energy Laboratory (NREL) has extensive capabilities for fabricating a variety of high-technology films. Much of the in-house work in NREL's large photovoltaics (PV) program involves the fabrication of multiple thin-film semiconducting layers constituting a thin-film PV device. NREL's smaller program in superconductivity focuses on the fabrication of superconducting films on long, flexible tape substrates. This paper focuses on four of NREL's in-house research groups and their film fabrication techniques, developed for a variety of elements, alloys, and compounds to be deposited on a variety of substrates. As is the case for many national laboratories, NREL's technology transfer efforts are focusing on Cooperative Research and Development Agreements (CRADA's) between NREL researchers and private industry researchers.

Mcconnell, Robert D.

1993-01-01

421

Fabrication of cellular materials  

NASA Astrophysics Data System (ADS)

Nature uses cellular materials in applications requiring strength while, simultaneously, minimizing raw materials requirements. Minimizing raw materials is efficient both in terms of the energy expended by the organism to synthesize the structure and in terms of the strength- to-weight ratio of the structure. Wood is the most obvious example of cellular bio-materials, and it is the focus of other presentations in this symposium. The lightweight bone structure of birds is another excellent example where weight is a key criterion. The anchoring foot of the common muscle [Mytilus edulis] whereby it attaches itself to objects is a further example of a biological system that uses a foam to fill space and yet conserve on raw materials. In the case of the muscle the foam is water filled and the foot structure distributes stress over a larger area so that the strength of the byssal thread from which it is suspended is matched to the strength of interfacial attachment of the foot to a substrate. In these examples the synthesis and fabrication of the cellular material is directed by intercellular, genetically coded, biochemical reactions. The resulting cell sizes are microns in scale. Cellular materials at the next larger scale are created by organisms at the next higher level of integration. For example an African tree frog lays her eggs in a gas/fluid foam sack she builds on a branch overhanging a pond. The outside of the foam sack hardens in the sun and prevents water evaporation. The foam structure minimizes the amount of fluid that needs to be incorporated into the sack and minimizes its weight. However, as far as the developing eggs are concerned, they are in an aqueous medium, i.e. the continuous fluid phase of the foam. After precisely six days the eggs hatch, and the solidified outer wall re-liquefies and dumps the emerging tadpoles into the pond below. The bee honeycomb is an example of a cellular material with exquisite periodicity at millimeter length scales. The cellular structure provides strength through geometric regularity and functions as both honey storage vessels and incubators.

Prud'homme, Robert K.; Aksay, Ilhan A.; Garg, Rajeev

1996-02-01

422

Fabrication of porous silicon membranes  

E-print Network

FABRICATION OF POROUS SILICON MEMBRANES A Thesis by WING KONG YUE Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1988 Major Subject: Electrical... Engineering FABRICATION OF POROUS SILICON MEMBRANES A Thesis by WING KONG YUE Approved as to style and content by: 8~zPm Donald L. Parker (Chairman of Committee) eung ( er) Karan L. Watson (Member) Washington H. Carlisle, III (Member) Jo W...

Yue, Wing Kong

2012-06-07

423

Fabrication and Characterization of Nanowires  

E-print Network

- dustries. In order to enhance the applicability of Shape Memory Alloys (SMAs) in systems such as Nano-Electromechanical Systems, the phase transformation behavior of SMA nanostructures should be explored. The primary focus of this work... is on the fabrication of metallic nanowires and the characterization of the phase transformation of SMA nanowires. Various metallic nanowires are fabricated through the use of the mechanical pressure injection method. The mechanical pressure injection method is a...

Phillips, Francis Randall

2011-10-21

424

Silicone nanocomposite coatings for fabrics  

NASA Technical Reports Server (NTRS)

A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

Eberts, Kenneth (Inventor); Lee, Stein S. (Inventor); Singhal, Amit (Inventor); Ou, Runqing (Inventor)

2011-01-01

425

Rapid optical fabrication with CCOS  

NASA Astrophysics Data System (ADS)

In the next decades, we foresee the need for the fabrication of many large asphenc mirrors for space and astronomy applications. Itek Optical Systems has developed computer controlled optical surfacing for rapidly fabricating such optics. Recently, these operations have been improved with the development of a sheaf of new processes based on a greatly increased understanding of the physics of glass surfacing. These improvements have already produced a reduction of large optics surfacing time and the technology points towards further reduction.

Jones, Robert A.; Rupp, Wiktor J.

1990-11-01

426

Silicon, iron and titanium doped calcium phosphate-based glass reinforced biodegradable polyester composites as bone analogous materials  

NASA Astrophysics Data System (ADS)

Bone defects resulting from disease or traumatic injury is a major health care problem worldwide. Tissue engineering offers an alternative approach to repair and regenerate bone through the use of a cell-scaffold construct. The scaffold should be biodegradable, biocompatible, porous with an open pore structure, and should be able to withstand the applied forces. Phosphate-based glasses (PGs) may be used as reinforcing agents in degradable composites since their degradation can be predicted and controlled through their chemistry. This doctoral dissertation describes the development and evaluation of PGs reinforced biodegradable polyesters for intended applications in bone augmentation and regeneration. This research was divided into three main objectives: 1) Investigating the composition dependent properties of novel PG formulations by doping a sodium-free calcium phosphate-based glass with SiO2, Fe2O3, and TiO2. Accordingly, (50P2 O5-40CaO- xSiO2-(10-x)Fe2O3, where x = 10, 5 and 0 mol.%) and (50P2O5-40CaO-xSiO 2-(10-x)TiO2 where x = 10, 7, 5, 3 and 0 mol.%) formulations were developed and characterised. SiO2 incorporation led to increased solubility, ion release, pH reduction, as well as hydrophilicity, surface energy, and surface polarity. In contrast, doping with Fe2O 3 or TiO2 resulted in more durable glasses, and improved cell attachment and viability. It was hypothesised that the presence of SiO 2 in the TiO2-doped formulations could up-regulate the ionic release from the PG leading to higher alkaline phosphatase activity of MC3T3-E1 cells. 2) Incorporating Si, Fe, and Ti doped PGs as fillers, either as particulates (PGPs) or fibres (PGFs), into biodegradable polyesters (polycaprolactone (PCL) and semi-crystalline and amorphous poly(lactic acid) (PLA and PDLLA)) with the aim of developing degradable bone analogous composites. It was found that PG composition and geometry dictated the weight loss, ionic release, and mechanical properties of the composites. It was also hypothesised that a potential reaction between Si and the ester bond led to the formation of carboxylate by-products resulting in a lower molecular weight polymer, thus affecting the mechanical properties of the composites. Cytocompatibility assessment with MC3T3-E1 pre-osteoblasts showed that these composites were cytocompatible, and cell alignment along the PGFs was observed possibly due to their favourable ionic release properties. 3) Investigating the solid-state foaming using carbon dioxide (CO 2) of PDLLA-PGP composites with up to 30 vol.% filler content. While PDLLA foams resulted in 92% porosity, the porosity of the composites ranged between 79 and 91% which decreased with PGP content. In addition, a reduction in pore size was observed with increasing PGP content; however, the pore size maintained its range of 200-500 ?m in all composite foams, suitable for bone tissue engineering applications. The percentage of open pores increased significantly with PGP content (up to 78% at 30 vol.% PGP). Compressive strength and modulus of PDLLA-PGP foams showed up to approximately 3-fold increase at 30 vol.% PGP content compared to neat PDLLA foams.

Shah Mohammadi, Maziar

427

Self-association and complexation of the anti-cancer drug doxorubicin with PEGylated hyperbranched polyesters in an aqueous environment.  

PubMed

Fully atomistic molecular dynamics simulations were employed in order to examine in detail the self-assembly characteristics and the complexation behavior of the anticancer drug doxorubicin with PEGylated hyperbranched polyesters in an aqueous environment. We have examined two variants of the polymeric compound by altering the length of the hydrophilic poly(ethylene glycol) arms attached to the hydrophobic hyperbranched core. By comparing the clustering properties of the drug molecules in a polymer-free system to those in the polymer-containing models, we were able to assess the effects related to the presence and to the structural features of the polymer moiety. In addition, we have distinguished the effects associated with the neutral and protonated drug molecules separately. It was found that, in the presence of the polymeric material, the drug molecules formed clusters preferentially close to the polymer's periphery, the characteristics of which depended on the structural details of the polymeric host and on the charge of the drug molecules. Hydrogen bonding was found to contribute to the polymer/drug complexation, with the nature of the prevailing donor/acceptor pairs depending on the charge of the drug. Dynamic analysis of the drugs' motion revealed that in the polymer-containing systems the drug molecules experienced a larger degree of confinement within the formed clusters compared to that describing their polymer-free analogues, while the structural coherence of the clusters was found to be more persistent in the system with the larger poly(ethylene glycol) arms. The results described in this work, through the monitoring of both static and dynamic aspects of the self-association and the complexation behavior of the neutral and charged molecules of doxorubicin with the polymeric host, may help toward the elucidation of the key parameters that are involved in the formation of effective polymer-based carriers for drug molecules of the anthracycline family used in cancer chemotherapy. PMID:23379643

Karatasos, K

2013-02-28

428

Long-term field performance of a polyester-based long-lasting insecticidal mosquito net in rural Uganda  

PubMed Central

Background In order to evaluate whether criteria for LLIN field performance (phase III) set by the WHO Pesticide Evaluation Scheme are met, first and second generations of one of these products, PermaNet®, a polyester net using the coating technology were tested. Methods A randomized, double blinded study design was used comparing LLIN to conventionally treated nets and following LLIN for three years under regular household use in rural conditions. Primary outcome measures were deltamethrin residue and bioassay performance (60 minute knock-down and 24 hour mortality after a three minute exposure) using a strain of Anopheles gambiae s.s. sensitive to pyrethroid insecticides. Results Baseline concentration of deltamethrin was within targets for all net types but was rapidly lost in conventionally treated nets and first generation PermaNet® with median of 0.7 and 2.5 mg/m2 after six months respectively. In contrast, second generation PermaNet® retained insecticide well and had 41.5% of baseline dose after 36 months (28.7 mg/m2). Similarly, vector mortality and knockdown dropped to 18% and 70% respectively for first generation LLIN after six months but remained high (88.5% and 97.8% respectively) for second generation PermaNet® after 36 months of follow up at which time 90.0% of nets had either a knockdown rate ? 95% or mortality rate ? 80%. Conclusion Second generation PermaNet® showed excellent results after three years of field use and fulfilled the WHOPES criteria for LLIN. Loss of insecticide on LLIN using coating technology under field conditions was far more influenced by factors associated with handling rather than washing. PMID:18355408

Kilian, Albert; Byamukama, Wilson; Pigeon, Olivier; Atieli, Francis; Duchon, Stephan; Phan, Chi

2008-01-01

429

Dibutyryl cAMP-inducible alkaline phosphatase in animal cell plasma membranes: fluorescence detection of mutant clones on polyester cloth.  

PubMed Central

We have developed a rapid screening assay that allows us to estimate the alkaline phosphatase content of mouse L-M cell colonies immobilized on polyester cloth. This permitted the identification and isolation of two mutant clones with increased constitutive alkaline phosphatase activity and six clones that fail to express this activity when treated with dibutyryl cyclic AMP. Both of the strains with increased constitutive activity have basal enzymatic activities that are 6- to 7-fold higher than the activity of the parental strain. The extents to which the cyclic nucleotide further induces alkaline phosphatase in these two strains are different, however, indicating that they represent two classes of mutants. Studies using amino acids and synthetic peptides as alkaline phosphatase inhibitors suggest that only one alkaline phosphatase isoenzyme predominates, in both the parental and the mutant cell lines, with or without induction by cyclic nucleotide. Comparison to mouse tissues indicates that our cell lines express an isozyme resembling that found in kidney and bone. The six clones that fail to express alkaline phosphatase activity when treated with dibutyryl cyclic AMP also have extremely low basal levels of the enzyme. All of these mutant strains continue to synthesize protein when treated with dibutyryl cyclic AMP and undergo growth cessation and morphological changes in the presence of this agent. Thus, the mutations all appear to affect factors specific to the expression of alkaline phosphatase activity rather than factors that affect general cellular responsiveness or permeability to dibutyryl cyclic AMP. The characterization of these strains may help elucidate mechanisms of eukaryotic membrane protein biogenesis, enzyme induction, and regulation of gene expression by cyclic nucleotides. Images PMID:6306651

Gum, J R; Raetz, C R

1983-01-01

430

Development of a biodegradable nanoparticle platform for sildenafil: formulation optimization by factorial design analysis combined with application of charge-modified branched polyesters.  

PubMed

Biodegradable nanoparticles have gained tremendous attraction as carriers for controlled drug delivery to the lung. Despite numerous advances in the field, e.g. development of suitable methods for pulmonary administration of polymeric nanoparticles, a sufficient association of the therapeutic agent with the carrier system as well as drug release in a controlled fashion remain considerable challenges. Hence, this study examines the optimization of biodegradable sildenafil-loaded nanoparticle formulations intended for aerosol treatment of pulmonary hypertension. A factorial design analysis was employed to identify the important experimental factors involved in the preparation of nanoparticles by the solvent evaporation technique. The effect of tailored charge-modified branched polyesters on drug loading and in vitro drug release from nanoparticles was also evaluated. Moreover, colloidal stability of obtained nanoparticles was assessed, and stabilization of nanoparticles by lyophilization was accomplished without additional excipients. Essential experimental factors were identified and optimized to allow the preparation of nanoparticles composed of linear polyesters with a sildenafil content of ~5 wt.%. The in vitro drug release profile from these nanoparticles demonstrated a sustained release of sildenafil over ~90 min. Application of charge-modified branched polyesters enhanced the drug content in nanoparticles and drug release profile, according to the charge-density present in the employed polymer. Accordingly an increase in drug loading by a factor of ~1.4, a prolonged drug release profile from nanoparticles over ~240 min was achieved. Sildenafil release from nanoparticles made of linear and charge-modified branched polyesters was governed by a diffusion process. The obtained drug diffusion coefficients were decreased as the charge-density present in the applied polymer was increased, which promotes the strategy to improve drug loading and release rates by electrostatic interactions between polymer and drug. In addition, nanoparticles showed high colloidal stability in different media of importance for pulmonary application and were successfully stabilized by lyophilization. In conclusion, optimization of the nanoparticle preparation process together with the application of tailored polymeric materials facilitated the synthesis of promising drug carriers for sildenafil that permit a novel treatment modality for severe pulmonary hypertension. PMID:21930166

Beck-Broichsitter, Moritz; Schmehl, Thomas; Gessler, Tobias; Seeger, Werner; Kissel, Thomas

2012-02-10

431

Improved Recovery of Bacillus Spores from Nonporous Surfaces with Cotton Swabs over Foam, Nylon, or Polyester, and the Role of Hydrophilicity of Cotton in Governing the Recovery Efficiency  

PubMed Central

Evaluating different swabbing materials for spore recovery efficiency (RE) from steel surfaces, we recorded the maximum RE (71%) of 107 Bacillus subtilis spores with Tulips cotton buds, followed by Johnson's cotton buds and standard Hi-Media cotton, polyester, nylon, and foam (23%) swabs. Among cotton swabs, instant water-absorbing capacity or the hydrophilicity index appeared to be the major indicator of RE, as determined by testing three more brands. Tulips swabs worked efficiently across diverse nonporous surfaces and on different Bacillus spp., registering 65 to 77% RE. PMID:23087040

Mujawar, Mohammed M.; Upreti, Reshmi; Sekhar, Aparna C.

2013-01-01

432

A facile method to fabricate superhydrophobic cotton fabrics  

NASA Astrophysics Data System (ADS)

A facile and novel method for fabricating superhydrophobic cotton fabrics is described in the present work. The superhydrophobic surface has been prepared by utilizing cationic poly (dimethyldiallylammonium chloride) and silica particles together with subsequent modification of (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane. The size distribution of silica particles was measured by Particle Size Analyzer. The cotton textiles before and after treatment were characterized by using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The wetting behavior of cotton samples was investigated by water contact angle measurement. Moreover, the superhydrophobic durability of coated cotton textiles has been evaluated by exposure, immersion and washing tests. The results show that the treated cotton fabrics exhibited excellent chemical stability and outstanding non-wettability with the WCA of 155 ± 2°, which offers an opportunity to accelerate the large-scale production of superhydrophobic textiles materials for new industrial applications.

Zhang, Ming; Wang, Shuliang; Wang, Chengyu; Li, Jian

2012-11-01

433

Fabric Performance in Clothing and Clothing Manufacture  

Microsoft Academic Search

After the performance of clothing fabric in use has been satisfied to some extent, consumers seek better-quality, that is, more comfortable, fabrics. Fabric performance in relation to ‘better fitting to the human body’ is an essential requirement of clothing materials. From the mechanical-comfort viewpoint, textile producers and consumers have evaluated this kind of fabric performance by a subjective method, called

S. Kawabata; Masako Niwa

1989-01-01

434

Fabrication of micro-optical devices  

NASA Technical Reports Server (NTRS)

We have fabricated a variety of micro-optic components including Fresnel and non-Frensel lenses, off-axis and dispersive lenses with binary stepped contours, and analog contours. Process details for all lens designs fabricated are given including multistep photolithography for binary fabrication and grayscale mask photolithography for analog fabrication. Reactive ion etching and ion beam milling are described for the binary fabrication process, while ion beam milling was used for the analog fabrication process. Examples of micro-optic components fabricated in both Si and CdTe substrates are given.

Anderson, W. W.; Marley, J.; Gal, George; Purdy, Don

1993-01-01

435

Structure and yarn sensor for fabric  

SciTech Connect

A structure and yarn sensor for fabric directly determines pick density in a fabric thereby allowing fabric length and velocity to be calculated from a count of the picks made by the sensor over known time intervals. The structure and yarn sensor is also capable of detecting full length woven defects and fabric. As a result, an inexpensive on-line pick (or course) density measurement can be performed which allows a loom or knitting machine to be adjusted by either manual or automatic means to maintain closer fiber density tolerances. Such a sensor apparatus dramatically reduces fabric production costs and significantly improves fabric consistency and quality for woven or knitted fabric.

Mee, David K. (Knoxville, TN); Allgood, Glenn O. (Powell, TN); Mooney, Larry R. (Knoxville, TN); Duncan, Michael G. (Clinton, TN); Turner, John C. (Clinton, TN); Treece, Dale A. (Knoxville, TN)

1998-01-01

436

Sacrificial bridges for MEMS fabrication  

NASA Astrophysics Data System (ADS)

This study discusses sacrificial bridges that are used to release MEMS devices. Before being released, sacrificial bridges connect all the component structures into an integral structure. Solder bump bonding is used to mount the MEMS chip on another chip or a printed circuit board (PCB) and to maintain the alignment among all component structures after removal of the sacrificial bridges. Two types of sacrificial bridges were designed, analyzed and fabricated. The fabrication process—which used low resistivity single crystal silicon (SCS) wafers as the device material—was developed to implement the sacrificial bridges. Novel SCS through silicon vias (TSVs), which interconnect stacked chips, was made using the same process. An electrostatic comb drive actuator was fabricated and mounted onto a PCB. The fabricated actuator was tested to demonstrate the feasibility of the fabrication process, sacrificial bridges and SCS TSVs. The results show that the actuator worked well. Its maximum displacement and resonant frequency were 69.9 µm and 406 Hz, respectively. This method is promising for the delivery of a novel 3D system in package for MEMS devices.

Chang, Chao-Min; Chen, Yang-Che; Fong, Chien-Fu; Guu, Yunn-Horng; Chen, Rongshun; Yeh, J. Andrew; Hou, Max T.

2011-09-01

437

Pulsed laser deposition of silicon dioxide thin films with silicone targets for fabricating waveguide devices  

NASA Astrophysics Data System (ADS)

Silicon dioxide (SiO2) thin films were deposited at room temperature by 193-nm ArF excimer laser ablation of silicone in oxygen atmosphere. Only the side chains of the target were photo-dissociated during ablation to deposit Si-O bonds on a substrate in high laser fluence at about 10 J/cm2. Oxygen gas worked to oxidize the Si-O bonds ejected from the target to from SiO2 thin films at the gas pressure of 4.4 X 10-2 Torr, in addition to reducing the isolated carbon mixed into the films. We also found that the deposited rate could control refractive index of the films. The refractive index of the film deposited at 0.05 nm/pulse is greater than that of the film at 0.1 nm/pulse. Thus, a 0.2-micrometers thick SiO2 cladding film deposited at 0.1 nm/pulse was firstly formed on the whole surface of a 100- micrometers -thick polyester film, and then a 0.6 micrometers -thick SiO2 core film at 0.05 nm/pulse was fabricated in a line on the sample. The sample functioned as a waveguide device for a 633-nm line of He-Ne laser.

Okoshi, Masayuki; Kuramatsu, Masaaki; Inoue, Narumi

2002-06-01

438

The testing of balloon fabrics  

NASA Technical Reports Server (NTRS)

Report describes methods and materials used in waterproofing and fireproofing airplane fabrics using dopes. The determination of the probable life of a balloon fabric in service by experimental means is of great value in choosing the most suitable fabrics for a given purpose and in pointing the way to improvements in compounding and construction. The usefulness of exposure to the weather for this purpose has been amply demonstrated. Various attempts have been made to reproduce by artificial means the conditions promoting deterioration in service, but without marked success. Exposure to the weather remains the most satisfactory method for this purpose, and a consideration of the characteristics of such tests is therefore important. This report presents the results of a typical series of exposure tests made in 1917.

Edwards, Junius David; Moore, Irwin L

1920-01-01

439

Interplay between viscoelastic and chemical tunings in fatty-acid-based polyester adhesives: engineering biomass toward functionalized step-growth polymers and soft networks.  

PubMed

This Article describes the synthesis and characterization of renewable self-adhesive coatings with tunable viscoelastic properties and equipped with well-defined amounts of carboxylic acid "sticker" groups with adhesion promoting characteristics. Hydroxyl-ended polyesters with various architectures (linear, branched) were synthesized by melt polycondensation of dimerized fatty acids and fatty diols and then cured with maleic anhydride-modified triglycerides (such as maleinized soybean oil) in the presence of the amidine catalyst 1,8-diazabicyclo[5.4.0]undec-7-ene. The curing reaction of alcoholysis has the dual effect of chain extending/cross-linking the base polymers via creation of polymeric half-esters linkages while introducing carboxylic acid functions within the gel structure. We demonstrated how the adhesion properties can be finely tuned from molecular design and formulation of the network precursors and how the rheology and functionality of the coatings influence the adhesive bond formation and development. These renewable polyester adhesives proved to be suitable materials for pressure-sensitive adhesives applications with respect to adhesion strength, viscoelasticity, and functionality. In addition, the environmental benefits of such materials are briefly discussed. PMID:22612310

Vendamme, Richard; Olaerts, Katrien; Gomes, Monica; Degens, Marc; Shigematsu, Takayuki; Eevers, Walter

2012-06-11

440

A method of test for residual isophorone diisocyanate trimer in new polyester-polyurethane coatings on light metal packaging using liquid chromatography with tandem mass spectrometric detection.  

PubMed

A method of test for residual isophorone diisocyanate (IPDI) trimer in experimental formulation polyester-polyurethane (PEPU) thermoset coatings on metal food packaging is described. The method involves extraction of coated panels using acetonitrile containing dibutylamine for concurrent derivatisation, and then high performance liquid chromatography with electrospray ionisation tandem mass spectrometric detection (LC-MS/MS). Single laboratory validation was carried out using three different experimental PEPU-based coatings. The calibrations were linear, the analytical recovery was good, no interferences were seen, and substance identification criteria were met. The detection limit of the method is around 0.02 micro g/100 cm(2) of coating, which for a typical sized can and assuming complete migration of any residual IPDI trimer, corresponds to about 0.2 micro g/kg food or beverage. Separate studies indicated that, even if migration occurred at such low levels, the IPDI trimer would not be expected to persist in canned aqueous or fatty foodstuffs as it would hydrolyse to the corresponding aliphatic amine or react with food components to destroy the isocyanate moiety. The method of test developed here for residual IPDI trimer in thermoset polyester-polyurethane coatings should prove to be a valuable tool for investigating the cure kinetics of these novel coatings and help to guide the development of enhanced formulations. PMID:17178416

Driffield, Malcolm; Bradley, Emma L; Castle, Laurence

2007-02-01

441

Effects of hydrophobic drug polyesteric core interactions on drug loading and release properties of poly(ethylene glycol) polyester poly(ethylene glycol) triblock core shell nanoparticles  

NASA Astrophysics Data System (ADS)

BAB amphiphilic triblock copolymers consisting of poly(ethylene glycol) (B) (PEG) as the hydrophilic segment and different polyesters (A) as the hydrophobic block were prepared by a polycondensation reaction as efficient model core-shell nanoparticles to assay the effect of interactions between the hydrophobic drug and the polyesteric core in terms of drug loading content and release profile. PEG-poly(hexylene adipate)-PEG (PEG-PHA-PEG) and PEG-poly(butylene adipate)-PEG (PEG-PBA-PEG) to PEG-poly(ethylene adipate)-PEG (PEG-PEA-PEG) core-shell type nanoparticles entrapping quercetin (an anticarcinogenic, allergy inhibitor and antibacterial agent), were prepared by a nanoprecipitation method and characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and x-ray diffraction (XRD) techniques. It was found that the obtained nanoparticles showed a smooth surface and spherical shape with controllable sizes in the range of 64-74 nm, while drug loading varied from 7.24% to 19% depending on the copolymer composition and the preparation conditions. The in vitro release behaviour exhibited a sustained release and was affected by the polymer-drug interactions. UV studies revealed the presence of hydrogen bonding as the main existing interaction between quercetin and polyesters in the nanosphere cores.

Khoee, Sepideh; Hassanzadeh, Salman; Goliaie, Bahram

2007-05-01

442

Periadventitial atRA citrate-based polyester membranes reduce neointimal hyperplasia and restenosis after carotid injury in rats.  

PubMed

Oral all-trans retinoic acid (atRA) has been shown to reduce the formation of neointimal hyperplasia; however, the dose required was 30 times the chemotherapeutic dose, which already has reported side effects. As neointimal formation is a localized process, new approaches to localized delivery are required. This study assessed whether atRA within a citrate-based polyester, poly(1,8 octanediolcitrate) (POC), perivascular membrane would prevent neointimal hyperplasia following arterial injury. atRA-POC membranes were prepared and characterized for atRA release via high-performance liquid chromatography with mass spectrometry detection. Rat adventitial fibroblasts (AF) and vascular smooth muscle cells (VSMC) were exposed to various concentrations of atRA; proliferation, apoptosis, and necrosis were assessed in vitro. The rat carotid artery balloon injury model was used to evaluate the impact of the atRA-POC membranes on neointimal formation, cell proliferation, apoptosis, macrophage infiltration, and vascular cell adhesion molecule 1 (VCAM-1) expression in vivo. atRA-POC membranes released 12 ?g of atRA over 2 wk, with 92% of the release occurring in the first week. At 24 h, atRA (200 ?mol/l) inhibited [(3)H]-thymidine incorporation into AF and VSMC by 78% and 72%, respectively (*P = 0.001), with negligible apoptosis or necrosis. Histomorphometry analysis showed that atRA-POC membranes inhibited neointimal formation after balloon injury, with a 56%, 57%, and 50% decrease in the intimal area, intima-to-media area ratio, and percent stenosis, respectively (P = 0.001). atRA-POC membranes had no appreciable effect on apoptosis or proliferation at 2 wk. Regarding biocompatibility, we found a 76% decrease in macrophage infiltration in the intima layer (P < 0.003) in animals treated with atRA-POC membranes, with a coinciding 53% reduction in VCAM-1 staining (P < 0.001). In conclusion, perivascular delivery of atRA inhibited neointimal formation and restenosis. These data suggest that atRA-POC membranes may be suitable as localized therapy to inhibit neointimal hyperplasia following open cardiovascular procedures. PMID:25239800

Gregory, Elaine K; Webb, Antonio R; Vercammen, Janet M; Flynn, Megan E; Ameer, Guillermo A; Kibbe, Melina R

2014-11-15

443

Gas-filled hohlraum fabrication  

SciTech Connect

Los Alamos National Laboratory (LANL) researchers have fabricated and fielded gas-filled hohlraums at the Lawrence Livermore National Laboratory (LLNL) Nova laser. Fill pressures of 1--5 atmospheres have been typical. We describe the production of the parts, their assembly and fielding. Emphasis is placed on the production of gas-tight polyimide windows and the fielding apparatus and procedure.

Salazar, M.A.; Gobby, P.L.; Foreman, L.R.; Bush, H. Jr.; Gomez, V.M.; Moore, J.E. [Los Alamos National Lab., NM (United States); Stone, G.F. [Lawrence Livermore National Lab., CA (United States)

1995-09-01

444

FABRIC FILTER MODEL SENSITIVITY ANALYSIS  

EPA Science Inventory

The report gives results of a series of sensitivity tests of a GCA fabric filter model, as a precursor to further laboratory and/or field tests. Preliminary tests had shown good agreement with field data. However, the apparent agreement between predicted and actual values was bas...

445

Four Fabric Structures. A Report.  

ERIC Educational Resources Information Center

Photographs and descriptions of four projects using fabric to enclose large spaces are published so that administrators and designers looking for ways to build recreational facilities can consider these innovative shelters. Three of the four examples in this publication are air-supported structures: University of Santa Clara, Charles Wright…

Green, Peter

446

DISTRIBUTED ROUTER FABRICS A DISSERTATION  

E-print Network

DISTRIBUTED ROUTER FABRICS A DISSERTATION SUBMITTED TO THE DEPARTMENT OF ELECTRICAL ENGINEERING every year, the demands placed on the IP routers that deliver this traffic also increase. Traditional IP router architectures cannot scale to meet these demands, forcing architects to explore alternative

Lee, Thomas H.

447

ELECTROSTATIC STIMULATION OF FABRIC FILTRATION  

EPA Science Inventory

The paper gives results of an investigation of the concept of electrostatic stimulation of fabric filtration (ESFF) at pilot scale. The pilot unit consisted of a conventional baghouse in parallel with an ESFF baghouse, allowing direct comparison. Reported results are for pulse-cl...

448

Fabrication of metallic glass structures  

DOEpatents

Amorphous metal powders or ribbons are fabricated into solid shapes of appreciable thickness by the application of compaction energy. The temperature regime wherein the amorphous metal deforms by viscous flow is measured. The metal powders or ribbons are compacted within the temperature regime.

Cline, C.F.

1983-10-20

449

Fabrication of metallic glass structures  

DOEpatents

Amorphous metal powders or ribbons are fabricated into solid shapes of appreciable thickness by the application of compaction energy. The temperature regime wherein the amorphous metal deforms by viscous flow is measured. The metal powders or ribbons are compacted within the temperature range.

Cline, Carl F. (Walnut Creek, CA)

1986-01-01

450

Reliable Systems on Unreliable Fabrics  

E-print Network

of Michigan, Ann Arbor Yu Cao Arizona State University, Tempe &THE CONTINUED SCALING of silicon fabrication these challenges. Its synergistic research projects include developing near-term reliability stress reduction tech power density and nonideal threshold and supply voltage scaling, wearout-related permanent errors

Bertacco, Valeria

451

Social Fabrics: Wearable + Media + Interconnectivity  

Microsoft Academic Search

Art as a garment, fused with sensing, media and network technology, can become a powerful means for investigating current forms of social interaction and the place of the body and self in digital society. The Leonardo Social Fabrics Gallery presents new works exploring this rich mix of old and new arts and technologies.

Susan Elizabeth Ryan

2009-01-01

452

Microjet fabrication of microlens arrays  

Microsoft Academic Search

Microjet, or inkjet, technology is used to fabricate lenslet arrays with packing densities greater than 15000\\/cm2. Typical lens diameters range between 70 and 150 ?m, and focal lengths are between 50 and 150 ?m. Individual lenslets are characterized in the Fraunhofer plane. The full array is characterized in its far field

D. L. MacFarlane; V. Narayan; J. A. Tatum; W. R. Cox; T. Chen; D. J. Hayes

1994-01-01

453

Comparison of Aedes aegypti (Diptera: Culicidae) resting behavior on two fabric types under consideration for insecticide treatment in a push-pull strategy.  

PubMed

Aedes aegypti (L.), the primary vector of dengue and dengue hemorrhagic fever, breeds and rests predominately inside human dwellings. With no current vaccine available, vector control remains the mainstay for dengue management and novel approaches continue to be needed to reduce virus transmission. This requires a full understanding of Ae. aegypti ecology to design effective strategies. One novel approach is the use of contact irritants at target resting sites inside homes to make the surface unacceptable and cause vectors to escape before biting. The objective of the current study was to observe indoor resting behavior patterns of female Ae. aegypti within experimental huts in response to two fabrics under consideration for insecticide treatment: cotton and polyester. Results indicate that fabric type, coverage ratio of dark to light fabric and placement configuration (vertical vs. horizontal) all influenced the resting pattern of mosquito cohorts. Findings from this study will guide evaluations of a push-pull strategy designed to exploit contact irritant behaviors and drive Ae. aegypti out of homes prefeeding. PMID:23427653

Tainchum, Krajana; Polsomboon, Suppaluck; Grieco, John P; Suwonkerd, Wannapa; Prabaripai, Atchariya; Sungvornyothin, Sungsit; Chareonviriyaphap, Theeraphap; Achee, Nicole L

2013-01-01

454

Novel fabric pressure sensors: design, fabrication, and characterization  

NASA Astrophysics Data System (ADS)

Soft and pliable pressure sensors are essential elements in wearable electronics which have wide applications in modern daily lives. This paper presents a family of fabric pressure sensors made by sandwiching a piece of resistive fabric strain sensing element between two tooth-structured layers of soft elastomers. The pressure sensors are capable of measuring pressure from 0 to 2000 kPa, covering the whole range of human-machine interactions. A pressure sensitivity of up to 2.98 × 10 - 3 kPa - 1 was obtained. Theoretical modeling was conducted based on an energy method to predict the load-displacement relationship for various sensor configurations. By adjusting the Young's modulus of the two conversion layers, as well as the geometrical dimensions, the measurement ranges, and sensitivities of the sensors can be quantitatively determined. The sensors are being used for pressure measurements between the human body and garments, shoes, beds, and chairs.

Wang, Yangyong; Hua, Tao; Zhu, Bo; Li, Qiao; Yi, Weijing; Tao, Xiaoming

2011-06-01

455

Laser target fabrication, structure and method for its fabrication  

DOEpatents

The disclosure is directed to a laser target structure and its method of fabrication. The target structure comprises a target plate containing an orifice across which a pair of crosshairs are affixed. A microsphere is affixed to the crosshairs and enclosed by at least one hollow shell comprising two hemispheres attached together and to the crosshairs so that the microsphere is juxtapositioned at the center of the shell.

Farnum, Eugene H. (Los Alamos, NM); Fries, R. Jay (Los Alamos, NM)

1985-01-01

456

Digital fabrication in the architectural design process  

E-print Network

Digital fabrication is affecting the architectural design process due to the increasingly important role it has in the fabrication of architectural models. Many design professionals, professors, and students have experienced ...

Seely, Jennifer C. K., 1975-

2004-01-01

457

A continuum model for needlepunched nonwoven fabrics  

E-print Network

Nonwoven fabrics are sheet structures created by bonding or interlocking a web (network) of fibers through mechanical, thermal or chemical processes. In general, the mechanical response of nonwoven fabrics exhibits two ...

Jearanaisilawong, Petch, 1979-

2008-01-01