INFLUENCE OF NUCLEATION PROMOTERS ON THE CRYSTALLIZATION OF POLY(ETHYLENE-TEREPHTHALATE)

A series of N-alkyl-p-toluenesulfonamides (ATSA) were synthesized and identified. The measurement of solution viscosity of poly(ethylene ter ephthalate) (PET) proved that ATSA does not react with PET during the melting process of PET/ATSA mixtures, and consequently does not cause any decrease of molecular weight of PET. The compatibility of ATSA wit h PET was investigated by polarized light and scanning electron micros copy. Phase separation could not be found to a 0.5 mu m level. The inv estigation of crystallization of PET/ATSA mixtures by me ans of differ ential scanning calorimetry revealed that ATSA significantly accelerat es the crystallization rate of PET; and that ATSA is more effective wh en increasing the length of alkyl chains within ATSA. The increase of crystallization rate of PET is proposed to be caused by the improvemen t of molecular motion of chains, which can be proved by the depression of glass transition temperature when ATSA is added.