Cyclohexylenedimethylene terephthalate copolyesters

Poly(butylene-co-l,4-cyclohexylenedimethylene terephthalate) copolyesters (PBCT) (Figure 6.9) with a random microstructure have been synthesized by melt polycondensation for a range of BD/1,4-CHDM ratios between 94/8 and 23/77 (47,48). PBCT are crystalline for all compositions and display an eutectic behavior. Copolyesters with less than 25 %mol of CHDM units crystallize in a PBT like lattice whereas above 38 %mol they adopt a PCT-like lattice. PBCT copolyesters were found to be more stable than PCT and PBT at the initial stage of the thermal decomposition (49). 

CHDA CHDM DMCD EG IPA N NDA PCT PCTA PCTG PET PETG TMCD TPA cis/trans-1,4-cyclohexanedicarboxylic acid cis/trans-1,4-cyclohexanedimethanol dimethyl cis/trans-1,4-cyclohexanedicarboxylate ethylene glycol isophthalic acid dimethyl 2,6-naphthalenedicarboxylate 2,6-naphthalenedicarboxylic acid poly(1,4-cyclohexylenedimethylene terephthalate) dibasic-acid-modified PCT copolyester glycol-modified PCT copolyester poly(ethylene terephthalate) CHDM-modified PET copolyester c .S / ra .v-2,2,4,4-tetramethyl-l,3-cyclobutancdiol terephthalic acid... 

If BD is replaced by 1,6-hexanediol, the poly(hexamethylene-co-1,4-cyclohexylenedimethylene terephthalate) random copolyesters... 

Other thermoplastic polyesters have been reported, including copolyesters based on 1,4-cyclohexylenedimethylene glycol and terephthalic acid and polymers and copolymers of p-hydroxybenzoic acid. Little is known about established applications. Hot melt adhesives, based on polyesters made from adipic or phthalic acids with mono- or di-ethylene glycols or 1,4-butane diol, find use in shoe manufacture. 

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