Effects of Alkyl Chain Length of Aliphatic Dicarboxylic Ester on Degradation Properties of Aliphatic-Aromatic Water-Soluble Copolyesters for Warp Sizing

Abstract

In order to study the effects of alkyl chain length of aliphatic dicarboxylic ester (ADE) monomers on enzymatic and hydrolytic degradation properties of aliphatic-aromatic water-soluble copolyesters for warp sizing, dimethyl terephthalate, dimethyl isophthalate-5-sulfonic sodium, and ADE monomers with various alkyl chain lengths were copolymerized through a two-step method, i.e. transesterification and polycondensation. The enzymatic and hydrolytic degradation properties of the copolyesters were studied in terms of reduction rates of molecular weight, glass transition temperatures, and surface morphology after being cultivated for 24-96 h. It was found that, enzymatic degradation of the copolyesters strongly depended on alkyl chain length of ADE monomers. After being enzymatically degraded for 96 h, reduction rate of molecular weight of the copolyester using dimethyl malonate as ADE monomers could reach 22.2 %. Meanwhile, the hydrolytic degradation of the copolyesters was not directly related to the alkyl chain length.