Abstract: PTT was copolymerizing modified with 2-methy-1,3-propanediol (MPO) through melt esterification, and the melt crystallization behavior was studied by differential scanning calorimetry (DSC). It was found that when the MPO content was 20 %, the melting point of PTT decreased from 226.64 to 201.78 ℃; when the MPO contents was 10 %, the crystallization temperature was decreased from 159.0 to 137.5 ℃, and the half crystallization time (t1/2) increased. With increasing cooling rate, the crystallization temperature of each sample moved to lower temperature and the exothermic peak changed from narrow to wide and t1/2 decreased. In addition, the nonisothermal crystallization behavior of the modified PTT was studied with Jeziorny method, and it was found that the crystallization rate constant (Zc) of the PTT became lower than neat PTT, which indicated that the crystallization ability of PTT after adding MPO became poorer.

Key words: poly(trimethylene terephthalate), 2-methy-1, 3-propanediol, melting, nonisothermal crystallization