PREPARATION METHODS FOR COPOLYESTER AND ITS FIBER MODIFIED BY ALIPHATIC DIOL WITH SIDE CHAINS AND ISOPHTHALIC ACID BINARY ESTER 5-SODIUM OR POTASSIUM SULFONATE

摘要

Preparation methods for copolyester and its fiber modified by aliphatic diol with side chains and isophthalic acid binary ester 5-sodium or potassium sulfonate are disclosed. The copolyester is copolymerized by four kinds of monomers comprising terephthalic acid, ethylene glycol, isophthalic acid binary ester 5-sodium or potassium sulfonate and aliphaticdiol with side chains. The method comprises the following steps: synthesizing the copolyester by charging ethylene glycol and terephthalic acid into a first esterification kettle to carry out esterification; then, conveying the reaction materials into a second esterification kettle, charging isophthalic acid binary ester 5-sodium or potassium sulfonate for further esterification, wherein an aliphatic diol with side chains and ethylene glycol and terephthalic acid are charged into the first esterification kettle at the same time, or an aliphatic diol with side chains and isophthalic acid binary ester 5-sodium or potassium sulfonate are charged into the second esterification kettle to carry out esterification; then, conveying the reaction materials into a condensation kettle for condensation polymerization and obtaining copolyester product; during the copolymerization, the mole ratio of terephthalic acid, ethylene glycol, aliphatic diol with side chains and isophthalic acid binary ester 5-sodium or potassium sulfonate is 1:1.1-2.4:0.05-0.20:0.015-0.07. The copolyester can be polymerized continuously and spun into fiber directly.