Poly terephthalic acid: sebacic

Poly(butyleneglycol-a/f-(terephthalic acid-sebacic acid)) 2047... 

A large number of dibasic acids and anhydrides are used in the preparation of poly(ester amide)s. These include terephthalic acid, phthalic anhydride, isophthalic acid, endic endo-cis bicyclo(2,2,10-5)-heptene-2,3-dicarboxylic] anhydride, hydrogenated endic anhydride, maleic anhydride, fumaric acid, dichloromaleic anhydride, itaconic acid, brassylic acid, dimer acid, adipic acid, sebacic acid, succinic acid, trimeUitic anhydride, pyrromellitic anhydride and ethylenediamine tetraacetic acid (EDTA). However, tri- and poly-functional compounds are used only partially and are combined with bifunctional derivatives, or derivatives of previously prepared multifunctional compounds which are subsequently polymerised with bifunctional compounds. 

In 1994, Witt and co-workers [5] first reported a microbial degradation of a block-copolyester [poly(trimethylene decanoate)-block-(trimethylene terephthalate)] with 50 mol% of terephthalic acid in the acid component. In a mineral medimn inoculated with sewage sludge, Witt and co-workers observed a weight loss in polyester films of about 9% within four weeks. In 1995 the same authors published data about the degradation of random aliphatic-aromatic copolyesters from terephthalic acid, 1,3-propanediol and adipic acid or sebacic acid (30 mol% of terephthalic acid content) in a soil burial experiment... 

The saturated polyesters that find conunercial applications are mostly linear, except for some specially prepared branched polymers used in the preparation of polyurethanes. The linear polyesters became commercially important materials early in this century and still find many uses in industry. The earliest studies reported condensations of ethylene, trimethylene, hexamethylene, and de-camethylene glycols with malonic, succinic, adipic, sebacic, and orthophthalic acids. Later studies showed that such condensations yield high molecular weight compounds. Nevertheless, these polyesters exhibit poor hydrolytic stability and are generally low-melting. Subsequently, however, it was found that aromatic dicarboxylic acids yield polymers with high melting points, and poly(ethylene terephthalate), which melts at 265 C, is now an important commercial material. 

In standard classification for vinyl plastics used in biomedical applications, a plasticizer is specified with prefix letter The letter is followed by a number from 1 to 14 which characterizes the type of plasticizer (e g., 1 - none, 2 - adipic acid derivative, 3 -azelaic, 4 - benzoic, 5 - citric, 6 - isophthalic, 7 - myristic, 8 - phosphoric, 9 - phthalic, 10 - sebacic, 11 - terephthalic, 12 - poly ether, 13 - polyethylene glycol, 14 - polyesters, 999 - other). The second letter specifies secondary plasticizer (e.g., A - none, B - alkyl epoxy stearates, C - epoxidized tall oil, D - epoxidized soybean oil, E - epoxidized linseed oil, F - epoxidized sunflower oil, Z - other). This classification is used to guide design engineers. Classification is not applicable to long-term implants. If there is a conflict between provisions of this standard and detailed specification for a particular device, the latter takes precedence. 

Poly( 1,3-propandiol-terephthalic-sebacic acid) - monomers molar ratio [97]... 

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