CRYSTALLIZATION BEHAVIOR OF A POLYESTER POLYAMIDE BLOCK COPOLYMER

Block copolymers of polyesters and polyamides have significant commercial importance in various applications utilizing a combination of properties of these two species. The block copolymers are made by carrying out copolycondensation between the oligomers of the polyester and polyamide. The PET component may vary from 30 to 70 wt%. The primary aim of this work was to investigate the crystallization behavior of these polyester-polyamide block copolymers. It is shown that copolymers with higher PET amounts crystallize with relative ease while those with lower PET amounts do not show significant crystallization. With this view, the copolymer containing 65 wt % PET was chosen for most of the work reported herein. This copolymer had a weight-average molecular weight of about 50,000 and a melting point of about 210. 0 degree C. A series of light-scattering patterns for samples melt crystallized at 140 degree C is included in this report along with photomicrograph of the sample crystallized at 140 degree C for 150 min.