Polyesters P

Worked into cast resins based on methacrylate or unsaturated polyester, P.V.23 has the advantage of being fast to peroxides, which act as catalysts in these media. The lightfastness of such systems is between step 7 and step 8 on the Blue Scale, both for transparent and opaque colorations. 

Figure 10.8 Expansion coefficient in rubbery state for amine-crosslinked epoxies, E (O), and for crosslinked aliphatic polyesters, P (<0>), versus crosslink density (n).

The most general and specific aspect of thermal aging of polymer networks is the existence of a postcuring effect, often predominant in the early time of exposure (Fig. 14.19). The curves exhibit a maximum (for the ultimate stress of unsaturated polyesters, P can increase by more... 

Polyester P-373 Unsaturated polyester Marco Division, W. R. Grace... 

SIN 3. Equal weights of polyester P-373 (including styrene and benzoyl peroxide) and polyurethane PU-1 (including TP-440 and T-9)... 

Phase behaviour and erystallisation kinetics for the binaiy blend P(3HB)/ eellulose propionate (CP) were performed by Maekawa et Cellulose aeetate butyrate (CAB), which has a combination of high (160 °C) and Tg (113 °C), is an important thermoplastic cellulose ester that can biodegrade in a natural environment. In an attempt to make the best use of degradable polyester P(3HB), Wang et al. blended P(3HB) with CAB and studied the relationship between the blend morphology and its physieal properties. 

P 25 3-Pentenoic acid, 3-hydroxy-2,2,4-trimethyl-, polyester P 26 l-Pentene-3-one, (stereoregular)... 

Akmal D, Azizan MN, Majid MIA (2003) Biodegradation of microbial polyesters P(3HB) and P (3HB-CO-3HV) under the tropical climate environment Polym Degrad Stab 80 513-518 Anandhan S, Bandyopadhyay S (2011) Polymer nanocomposites from synthesis to applications. 

The programs varied due to the kind of resin binder (epoxy E or two kinds of polyester P), the maximal diameter of gravel grain (4 or 10 mm) and the dimension of the experimental domain (Table 2). 

HOCHj CHjOH. Colourless, odourless, rather viscous hygroscopic liquid having a sweet taste, b.p. 197 C. Manufactured from ethylene chlorohydrin and NaHC03 solution, or by the hydration of ethylene oxide with dilute sulphuric acid or water under pressure at 195°C. Used in anti-freezes and coolants for engines (50 %) and in manufacture of polyester fibres (e.g. Terylene) and in the manufacture of various esters used as plasticizers. U.S. production 1979 1 900 000 tonnes. 

H02C(CH2)2C02H. Colourless prisms m.p. 182 C, b.p. 235°C. Occurs in amber, algae, lichens, sugar cane, beets and other plants, and is formed during the fermentation of sugar, tartrates, malates and other substances by a variety of yeasts, moulds and bacteria. Manufactured by the catalytic reduction of maleic acid or by heating 1,2-dicyanoethane with acids or alkalis. Forms an anhydride when heated at 235°C. Forms both acid and neutral salts and esters. Used in the manufacture of succinic anhydride and of polyesters with polyols. 

Crystallizes in colourless needles m.p. 300° (sublimes). Manufactured by the oxidation of p-xylene and used in the production of Terylene (see also polyesters). U.S. production 1980 2-05 megatonnes. 

The carboxylic acid produced m the greatest amounts is 1 4 benzenedicarboxylic acid (terephthahc acid) About 5 X 10 Ib/year is produced m the United States as a starting material for the preparation of polyester fibers One important process converts p xylene to terephthahc acid by oxidation with nitric acid... 

Poly(ethylene terephthalate), the predominant commercial polyester, has been sold under trademark names including Dacron (Du Pont), Terylene (ICI), Eortrel (Wellman), Trevira (Hoechst-Celanese), and others (17). Other commercially produced homopolyester textile fiber compositions iaclude p oly (1,4-cyc1 oh exa n e- dim ethyl en e terephthalate) [24936-69-4] (Kodel II, Eastman), poly(butylene terephthalate) [26062-94-2] (PBT) (Trevira, Hoechst-Celanese), and poly(ethylene 4-oxyben2oate) [25248-22-0] (A-Tell, Unitika). Other polyester homopolymer fibers available for specialty uses iaclude polyglycoHde [26124-68-5] polypivalolactone [24937-51-7] and polylactide [26100-51-6],... 

TrialkylPhosphates. Triethyl phosphate [78-40-0] C H O P, is a colorless Hquid boiling at 209—218°C containing 17 wt % phosphoms. It may be manufactured from diethyl ether and phosphoms pentoxide via a metaphosphate intermediate (63,64). Triethyl phosphate has been used commercially as an additive for polyester laminates and in ceHulosics. In polyester resins, it functions as a viscosity depressant as weH as a flame retardant. The viscosity depressant effect of triethyl phosphate in polyester resins permits high loadings of alumina trihydrate, a fire-retardant smoke-suppressant filler (65,66). 

This phosphinic anhydride [15171 -48-9] C H O P, is then reacted with glycol and other precursors of poly(ethylene terephthalate), to produce a flame-retardant polyester [82690-14-0] having phosphinate units of the stmcture —0P(0)(CH2)CH2CH2C00—. Trevira 271 is useflil for children s sleepwear, work clothing, and home flirnishings. A phosphoms content as low as 0.6% is reported to be sufficient for draperies and upholstery tests if melt-drip is not retarded by print pigments or the presence of nonthermoplastic fibers (28). 

Alternative technology for modifying a poly(aLkylene terephthalate) by incorporation of a phosphinate stmcture has been developed by Enichem. Phosphinate units of the stmcture —P(CgH5) (0)CH20— are introduced into a polyester such as PET or PBT by transesterification with an oligomer comprised of the aforementioned units (136). 

Property AST M test ABS Noryl a Nylon b P< Polyeste d r HD PE Polypropyle ne High impact polystyrene Polyurethane PV C... 

Another principal use of ketene is in the production of sorbic acid [110-44-1] (80,81). In this process, which requires an acidic or manganese(II) catalyst, ketene adds to crotonaldehyde [123-73-9] (8) with subsequent conversion of the P-lactone and the polyester to sorbic acid (qv) (9). 

Unsaturated Polyester Resius," Chemical Economics Handbook, SRI International, Menlo Park, Calif., July 1993, p. 580.1200A. 

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