Structural Effects of Ester and Benzenedicarboxylate Units on the Behaviors of Water-soluble Polyester Film

摘要

In order to obtain reasonable ester and benzenedicarboxylate units of water-soluble polyester (WSP) to improve its performance for warp sizing, the present paper investigates the effects of the structural units on mechanical behaviors of WSP film. The film behaviors are evaluated in terms of tensile strength and breaking elongation. With the decrease in the length of glycol ester unit, the film behaviors are significantly improved. Meanwhile, with the increase in the amount of dimethyl isophthalate-5-sodium sulfonic (SIPM) and dimethyl isophthalate (DMI), the tensile strength obviously decreases and breaking elongation increases. Suitable monomers for the preparation of WSP sizes are composed of ethylene glycol (EG), dimethyl terephthalate (DMT), SIPM and DMI. The molar ratio of DMT/DMI/SIPM should be 76.5/8.5/15.0. Based on the experimental results, a preferred structure of WSP sizes with better film behaviors required in warp sizing operation is achieved and it benefits the enhancement in service performance of WSP specialized for sizing polyester yarns.