Abstract: End-group modified poly(trimethylene terephthalate) polyester (PTT-TFA) was prepared by the esterification reaction between the hydroxyl end-groups of PTT and trifluoroacetic acid at room temperature, and its thermal properties were investigated by using the differential scanning calorimetry (DSC). The results show that the melting point of PTT-TFA was 227.3 ℃, which is equal to pure PTT, but the crystallization temperature is lower than that of pure PTT. Furthermore, the crystallization rate of PTT-TFA is also lower than that of pure PTT. The effective activation energy of crystallization calculated by Friedman method also concludes that the PTT-TFA has lower crystallization ability than pure PTT. Since the end-groups of the modified polymer were larger than that of the pure PTT, the mobility of the molecular chain was decreased; this lowered the rate of melt-crystallization.

Key words: PTT, TFA, crystallization kinetics, DSC