Poly(ethylene terephthalate) (PET) copolymers were prepared by melt polycondensation of dimethyl terephthalate and excess ethylene glycol with 5-30 mol% (in feed) of 1,3-propanediol and 2,2-dialkyl-l,3- propanediols, where the dialkyl groups are dimethyl, diethyl and butyl-ethyl. No significant depression of reduced specific viscosity was observed. The comonomer contents in the copolymers are considerably smaller than those in the feed. The crystallinities and densities of heat-treated films decreased with increasing content of comonomer and length of alkyl side chain in the comonomer. The glass transition temperature (Tg) and melting temperature (Tin) were decreased by the copolymerization, while an increase in the length of the alkyl side chain hardly affected the T m depression of heat-treated films. Alkali resistance, dyeability and thermal shrinkage were remarkably increased by the incorporation of comonomer having an alkyl side chain.
Посилання на статтю:
Preparation and properties of poly(ethylene terephthalate) copolymers with 2,2-dialkyl-1,3-propanediols / Tsuyoshi Kiyotsukuri, Tsuyoshi Masuda and Naoto Tsutsumi // Polymer. – 1994. – Vol 35. – P. 1274-1279.