Cyclic polybutylene terephthalate

The hydroformylation of acrolein cyclic acetals has received considerable attention in the recent patent literature as a route to 1,4-butanediol (76-52). This diol is a comonomer for the production of polybutylene terephthalate, an engineering thermoplastic. The standard method for its manufacture has been from acetylene and formaldehyde, as shown in Eqs. (37) and (38) ... 

Heating polybutylene terephthalate with 3 mol% of a tin catalyst in o-dichlorobenzene converted it to cyclic oligomers, which might be of value in reaction injection molding.204... 

Jones and co-workers [228] used particle beam liquid chromatography coupled with a MS detector to determine styrene oligomers up to the w-18 oligomer of PS. Bryant and Semiyen [229] analysed cyclic oligomers of polybutylene terephthalate using column chromatography GPC (size exclusion), fast atom bombardment mass spectrometry, and tandem mass spectrometry (MS-MS). They obtained molecular weight distributions. 

Figure 4.62 Cyclical transition state of polyesters under thermal degradation during processing 4.3.7.1 Polybutylene Terephthalate...

Bryant and Semiyen [18] analysed cyclic oligomers from polybutylene-terephthalate (PBT) using column chromatography, fast atom bombardment mass spectroscopy, liquid chromatography tandem mass spectroscopy, and NMR spectroscopy. 

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