Effect of comonomer on structure and properties of textured cationic dyeable polyester

Abstract

Cationic dyeable polyester (CDPET) yarns were produced through melt blending of cationic dyeable chips having 2 mol % of sodium salt of dimethyl ester of 5-sulfoisophthalic acid (DMS salt) and normal polyester chips in different proportions to obtain yarns having varying amount of comonomer in the fiber. These different partially oriented CDPET yarns were texturized under identical conditions on a draw-texturing machine. It has been observed that with increase in the amount of salt content in the CDPET, the dye uptake increases, but the tensile and crimp properties are adversely affected. The crystalline content, crystal size, overall orientation, and heat of fusion decrease with increase in salt content in CDPET yarns. The dyeability of CDPET yarns with both disperse dyes and cationic dyes improves with increase in DMS salt content. The changes in the mechanical and dyeing properties of textured CDPET have been explained on the basis of structural studies. © 1996 John Wiley & Sons, Inc.