Synthesis of poly(trimethylene terephthalate) with low-melting point

A low-melting point copolyester was prepared by introducing the third(isophthalic acid) and the fourth(PEG) components into poly(trimethylene terephthalate) molecule during copolymerization.The molecular structure,crystallization behavior and thermal stability of the low-melting point copolyester were studied.The results showed that the introduction of the third component can reduce the melting point of polyester,while the crystallization ability of polyester was weakened.The copolyester lost its crystallization ability when the mole fraction of the third component was 30% of that of the total diacid.The introduction of the fourth component was an effective way to improve the crystallinity of polyester.The obtained copolyester had the melting point of 158 ℃ when the mole fraction of the third component was 35% and the mass fraction of fourth component accounted for 8% of those of the total diacid,respectively.The obtained low-melting point copolyester had good crystallization ability and thermal stability.