PRICE RELATIONSHIPS IN THE U.S. FIBER MARKETS: ITS IMPLICATIONS FOR COTTON INDUSTRY

The paper examined the price relationship between cotton and polyester. The results provide strong evidence of long term price transmissions and granger causality between cotton and polyester price as well as the asymmetry transmissions for cotton on cotton, cotton on polyester, and polyester on polyester price. However, we did not find any evidence that there exists asymmetry transmission for polyester price on cotton price. Our results also did not support the contemporaneous effects hypothesis between polyester price and cotton price.Demand and Price Analysis,

Using a polyester binder for the interlaminar toughening of glass/epoxy composite laminates

Bisphenol A based polyester is commonly used in the industry as a binder, or tackifier, to produce cost-saving preforms in Liquid Composite Moulding processes such as Vacuum Assisted Resin Transfer Moulding (VARTM). However, it is often reported that the presence of these polyesters has a detrimental effect on the mechanical properties of the resulting composite laminates. This study shows that interlaminar toughness can be increased without negatively affecting other properties by a applying a bisphenol A based polyester binder. Both polyester modified epoxy resin as well as polyester modified glass/epoxy laminates are studied. It is shown that the presence of the polyester has a profound effect on the curing characteristics and glass transition temperature of the epoxy resin. Furthermore, fracture toughness experiments (Single Edge Notch Bending) show that there is an optimum polyester concentration which leads to a toughened epoxy matrix. Composite laminates are produced from binder coated glass fibre plies with VARTM. Double Cantilever Beam fracture experiments show that the polyester binder increases the Mode I interlaminar toughness by 60 %. Three point bending experiments show that the flexural properties were not negatively affected by the presence of the polyester in the interlaminar region between plies

Isohexide and sorbitol-derived, enzymatically synthesized renewable polyesters with enhanced Tg

Sugar-based polyesters derived from sorbitol and isohexides were obtained via solvent-free enzymatic catalysis. Pendant hydroxyl groups, coming from the sorbitol units, were present along the polyester backbone, whereas the two isohexides, namely, isomannide and isoidide dimethyl ester monomers, were selected to introduce rigidity into the polyester chains. The feasibility of incorporating isomannide as a diol compared to the isoidide dimethyl ester as acyl-donor via lipase-catalyzed polycondensation was investigated. The presence of bicyclic units resulted in enhanced Tg with respect to the parent sorbitol-containing polyester lacking isohexides. The different capability of the two isohexides to boost the thermal properties confirmed the more flexible character provided by the isoidide diester derivative. Solvent-borne coatings were prepared by cross-linking the sugar-based polyester polyols with polyisocyanates. The increased rigidity of the obtained sugar-based polyester polyols led to an enhancement in hardness of the resulting coatings.Peer ReviewedPostprint (author's final draft

Surface modification of polyester using chicken feather keratin hydrolysate to improve water absorbency and dye uptake

PET fiber has an intrinsic low hydrophilic character and an inactive surface which make it uncomfortable for wearing purpose. Moreover, it is difficult to colour polyester fabric other than disperse dyes. Therefore, surface modification of PET is very important to improve its absorbency and bring the possibility to dye polyester with anionic dyes by altering its surface characteristics. This research was focused on surface modification of polyester using chicken feather which involves serine as the most abundant amino acid with hydroxyl groups. The treated polyester fabric using 20ml/L concentration of chicken feather extract showed improved water drop absorbency from 45 into 3 seconds and the reactive dye uptake by 36 folds from 0.15 to 5.37 K/S values

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

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

Polyester textile functionalization through incorporation of pH/thermo-responsive microgels. Part II: polyester functionalization and characterization

A new approach to functionalize the surface of polyester textiles is described in this study. Functionalization was achieved by incorporating pH/temperature-responsive polyelectrolyte microgels into the textile surface layer using UV irradiation. The aim of functionalization was to regulate polyester wettability according to ambient conditions by imparting stimuli-responsiveness from the microgel to the textile itself. Microgels consisted of pH/thermo-responsive microparticles of poly(N-isopropylacrylamide-co-acrylic acid) either alone or complexed with the pH-responsive natural polysaccharide chitosan. Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, ζ-potential measurements, and topographical analysis were used for surface characterization. Wettability of polyester textiles was assessed by dynamic wetting, water vapor transfer, and moisture regain measurements. One of the main findings showed that the polyester surface was rendered pH-responsive, both in acidic and alkaline pH region, owing to the microgel incorporation. With a marked relaxation in their structure and an increase in their microporosity, the functionalized textiles exhibited higher water vapor transfer rates both at 20 and 40 °C, and 65% relative humidity compared with the reference polyester. Also, at 40 °C, i.e., above the microgel Lower Critical Solution Temperature, the functionalized polyester textiles had lower moisture regains than the reference. Finally, the type of the incorporated microgel affected significantly the polyester total absorption times, with an up to 300% increase in one case and an up to 80% decrease in another case. These findings are promising for the development of functional textile materials with possible applications in biotechnology, technical, and protective clothin

Structure-property relationships in low-temperature adhesives

Adhesive materials of aliphatic polyester, linear hydroxyl end-capped polybutadienes, or SBS block copolymers are studied with the objective to replace conventional partially aromatic end-reactive polyester-isocyanate adhesives that have shown embrittlemen

The co-movement between cotton and polyester prices

The authors examine the price linkages among polyester (the dominant chemical fiber), cotton (the dominant natural fiber), and crude oil (the dominant energy commodity), based on monthly data between 1980 and 2002. The modeling framework incorporates several aspects of the unit root econometrics literature. They find that: a) There is strong co-movement between cotton and polyester prices, well above the co-movement observed between these two prices and prices of other primary commodities. b) Crude oil prices have a stronger effect on polyester prices compared with cotton prices. c) Price shocks originating in the polyester market are transmitted at much higher speed to the cotton market than vice-versa.Markets and Market Access,Access to Markets,Textiles, Apparel&Leather Industry,Environmental Economics&Policies,Crops&Crop Management Systems

Fluid containers and resealable septum therefor Patent

Manufacture of fluid containers from fused coated polyester sheets having resealable septu

Friction and morphology of magnetic tapes in sliding contact with nickel-zinc ferrite

Friction and morphological studies were conducted with magnetic tapes containing a Ni-Zn ferrite hemispherical pin in laboratory air at a relative humidity of 40 percent and at 23 C. The results indicate that the binder plays a significant role in the friction properties, morphology, and microstructure of the tape. Comparisons were made with four binders: nitrocellulose; poly (vinyledene) chloride; cellulose acetate; and hydroxyl-terminated, low molecular weight polyester added to the base polymer, polyester-polyurethane. The coefficient of friction was lowest for the tape with the nitrocellulose binder and increased in the order hydroxylterminated, low molecular weight polyester resin; poly (vinyledene) chloride; and cellulose acetate. The degree of enclosure of the oxide particles by the binder was highest for hydroxyl-terminated, low molecular weight polyester and decreased in the order cellulose acetate, poly (vinyledene) chloride, and nitrocellulose. The nature of deformation of the tape was a factor in controlling friction. The coefficient of friction under elastic contact conditions was considerably lower than under conditions that produced plastic contacts