Polyester classes

This polyester class comprises amorphous high-Tg copolyesters, known as amorphous polyarylates, and semicrystalline polyesters that often exhibit anisotropic hquid crystalline (LC) melts. Liquid crystalline polyesters are often termed as polyester LCPs. 

This type of lining was originally designed for the repair of sanitary services, and the first resins used belonged to the terephthalate polyester class. Interest at once centered on repairs to industrial waste lines and in some cases, it was obvious that better chemical resistance was required than that offered by this resin type. Although considerably more expensive, this same general system, but employing epoxy resins, is now also available. Of course, neither type resin is suitable for all waste exposures. 

Property Polyester/ Class Mat Polyester/Woven Glass Cloth... 

Hiltunen K, Seppala JV, Itavaara M, Harkonen M (1997) The biodegradation of lactic acid-based poly(ester-urethanes). J Environ Polym Degrad 5 167-173 Hossein AK, Seyed HJ, Ahmad A (2008) A review on homopolymer, blends, and nanocomposites of poly(trimethylene terephthalate) as a new addition to the aromatic polyesters class. Iran Polym J 17 19-38... 

Water-thinnable polyester coatings have been formulated with low molecular weight oligomeric hydroxy-terminated polyesters (171). Up to about 20% of water dissolves in a polyester-Class I MF resin binder, reducing the viscosity to about half This permits making solvent-free coatings. 

A blended flame retardant polyester (Class 1 wKh 3% antimony trioxide) for open-mould applications. 

Organic polyesters, obtained either from a diacid and a mono-alcohoi, or from poly-alcohols and a monoacid, or from di-alcohols and a diacid. This class represented 29% of the synthetic base market in France in 1992. 

Polyesters are a second class of condensation polymers and the principles behind their synthesis parallel those of polyamides Ester formation between the functional groups of a dicarboxylic acid and a diol... 

A new class of materials called smart tagged composites has been developed for stmctural health monitoring appHcations. These composites consist of PZT-5A particles embedded into the matrix resin (unsaturated polyester) of the composite (16). 

Polyesters are known to be produced by many bacteria as intracellular reserve materials for use as a food source during periods of environmental stress. They have received a great deal of attention since the 1970s because they are biodegradable, can be processed as plastic materials, are produced from renewable resources, and can be produced by many bacteria in a range of compositions. The thermoplastic polymers have properties that vary from soft elastomers to rigid brittie plastics in accordance with the stmcture of the pendent side-chain of the polyester. The general stmcture of this class of compounds is shown by (3), where R = CH3, n = >100, and m = 0-8. 

Heteroatom Chain Backbone Polymers. This class of polymers includes polyesters, which have been widely studied from the initial period of research on biodegradable polymers, polyamides, polyethers, polyacetals, and other condensation polymers. Their linkages are quite frequendy found in nature and these polymers are more likely to biodegrade than hydrocarbon-based polymers. 

A variety of thermosetting resins are used in SMC. Polyesters represent the most volume and are available in systems that provide low shrinkage and low surface profile by means of special additives. Class A automotive surface requirements have resulted in the development of sophisticated systems that commercially produce auto body panels that can be taken direcdy from the mold and processed through standard automotive painting systems, without additional surface finishing. Vinyl ester and epoxy resins (qv) are also used in SMC for more stmcturaHy demanding appHcations. 

In 1923, the first disperse dye was developed for dyeing cellulose acetate fibers. However, in recent years the most important appHcation of disperse dyes has been to dye polyester fibers. Accompanied by the rapid growth of polyester fibers after World War II, disperse dyes have currendy achieved the largest production among all dye classes in terms of quantity (106). 

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