Trimethylene glycol polyester

Polyesters. The first synthetic fiber forming polymer produced by Carothers and coworkers was an aliphatic polyester made from trimethylene glycol and a hexadecamethylene dicarboxylic acid. This polymer was low-melting (70°C) and hydrolytically unstable. In 1941, Whinfield and Dickson synthesized the first high-melting symmetrical linear aromatic polyester, polyethylene terephthalate, and found it to be a very useful product. ... 

DuPont and Shell have developed a new polyester, poly(trimethylene terephthalate) (PTT) (structure 19.38) that is structurally similar to PET, except that 1,3-propanediol (PDO) is used in place of ethylene glycol. The extra carbon in Sorona allows the fiber to be more easily colored giving a textile material that is softer with greater stretch. Further, it offers good wear and stain resistance for carpet use. The ready availability of the monomer PDO is a major consideration with efforts underway to create PDO from the fermentation of sugar through the use of biocatalysts for this conversion. Sorona and Lycra blends have already been successfully marketed. Sorona is also targeted for use as a resin and film. 

In a recent study (120), measurements were made of the molar cyclization equilibrium constants Kx for cyclics (0(CH2)i00C0(CH2)4C0)x with x = 1—5 in an undiluted equilibrate of poly(decamethylene adipate) (PDA) at 423 K, and for cyclics (0(CH2)30C0(CH2 )2 CO)x with x = 1-7 in an undiluted equilibrate of poly(trimethylene succinate) (PTS) at the same temperature. The polymers were prepared from dimethyl adipate and decamethylene glycol and from dimethyl succinate and 1,3-propane diol using tetraisopropyltitanate and equilibrated at the required temperature in four-necked glass reaction kettles. Cyclics were extracted from the polymeric equilibrates and analysed by g.p.c. by methods described in Ref. (120). Individual cyclics were also prepared from the polyesters by the general pyrolytic method of Carothers and these were used for identification and calibration purposes. 

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. 

PIT Incorporation of other adipic acids, such as sebacic acid, trimethylene isophthalate, p-cetoxybenzoic acid, and ethylene glycol units Seo et al. (2006), Chen et al. (2007), Wei et al. (2006), Ou (2002) Blended with polyesters to develop high-performance materials, including crystalline engineering thermoplastic polymers, amorphous engineering thermoplastic polymers, and thermoplastic elastomers Nadkami and Rath (2002), Run et al. (2007), Krutphan and Supaphol (2005), Jafari et al. (2005), Yavari et al. (2005)... 

Poly(ethylene terephthalate), the lowest cost and most commonly used polyester, is produced using ethylene glycol (EG) and either dimethyl terephthalate (DMT) or terephthahc acid (TPA) (see Table 7.1). Processes using DMT were commercialized first, but when very pure TPA became available, TPA processes became more economical for large-scale fiber production. Poly(butylene terephthalate) (PBT), produced fi-om 1,4 butanediol and DMT, is another commercially important polyester, which is used for computer housings and many other molded products. Poly(trimethylene terephthalate) (PTT), made from TPA and 1,3 propanediol, is a relatively new commercial polyester, that shows promise for... 

More elastic, less stiff polyesters can be prepared from diols with longer aliphatic chain lengths, eg, from propylene (3G) or butylene (4G) glycols in combination with terephthalic acid [see Poly(trimethylene terephthalate)]. These polymers crystallize in a form with significantly less extension of the molecule approximately 75 and 87% of the fully extended form for the 3GT and the 4GT polymers, respectively (12). 

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