INTERRELATIONSHIP BETWEEN THE CRYSTALLIZATION BEHAVIOR, INJECTION MOLDING CONDITIONS, AND MORPHOLOGY OF POLY(ETHYLENE TEREPHTHALATE)/POLY(METHYL METHACRYLATE) ALLOYS.

The thermal and isothermal crystallization behavior of PET/PMMA (poly(ethylene terephthalate)/poly(methyl methacrylate)) alloys was investigated. The crystallization of PET is accelerated significantly by alloying with PMMA. As a result, crystalline specimens could be injection molded with the alloy at low mold temperatures of 19 degree , 55 degree and 90 degree C, whereas a mold temperature of about 130 degree C is normally required for crystallinity to develop in the virgin PET grade. The impact strength of the alloy specimens increased significantly with decreasing mold temperature despite a comparable degree of crystallinity. The increase in impact strength is correlated to the reduction in the crystallite size and broadening of the crystal size distribution with decreasing mold temperature.