Abstract:

In order to study the influence of molecular structure of aliphatic dicarboxylic ester (ADE) monomers on sizing properties of aliphatic-aromatic water-soluble copolyesters, ADE monomers with various carbon chain length were chosen to prepare aliphatic-aromatic water-soluble copolyesters with different ester structures by transesterification-polycondensation. Then the copolyesters were blended with hydrolyzed starch to size polyester/cotton (65/35) warp yarns. The performance of the sized yarns was evaluated in terms of tensile strength, elongation, abrasion-resistance and the amount of hairiness. The results show that carbon chain length of ADE monomers has great effect on sizing properties of water-soluble copolyesters. The copolyester synthesized by dimethyl malonate (DMM) as aliphatic monomers exhibits better sizing properties than the other water-soluble polyesters. Compared with unsized yarns, the yarns sized by hydrolyzed starch the copolyester synthesized by DMM has tensile strength increased by 45.72% while the tensile elongation is decreased by only 11.73%. The abrasion number of the sized yarns is almost doubled and the hairiness amount of the yarns is decreased to a large extent. In addition, the biodegradability of the copolyester synthesized by DMM is much better than that of pure aromatic water-soluble polyester.

Key words: aliphatic monomer, ester structure, water-soluble copolyester, sizing properties, biodegradability, polyester/cotton