用熔融缩聚法合成了一系列聚(对苯二甲酸-1,3-丁二醇酯/对苯二甲酸-1,4-丁二醇酯)/聚乙二醇的嵌段共聚物.用FT-IR,1H-NMR,DSC,TGA,水降解测试等方法表征了材料的结构与性能.FT-IR和1H-NMR分析表明合成得到的共聚物为预期产物；DSC分析显示,共聚聚酯随着1,3-丁二醇在共聚物中比例的增大,熔点(Tm)逐渐降低,由158.24℃下降至104.19℃,玻璃化温度(Tg)逐渐升高,由4.86℃升至24.56℃,合成得到的共聚酯趋向于无定形态:TGA分析表明1,3-丁二醇在共聚酯中比例增大会使聚酯的热稳定性下降,但合成得到的共聚酯依然具有较好的热稳定性,初始分解温度大于310℃,不需要在反应过程中添加热稳定剂；水降解测试结果表明共聚物随1,3-丁二醇比例的增加,降解速率大幅提升.%A series of poly( 1,3-butylene terephthalate/1,4-butylene terephthalate)/PEG block copolymers were synthesized by melting polycondensation and characterized by means of Fourier transform infrared spectroscopic (FT-IR), hydrogen nuclear magnetic resonance spectrum (1H-NMR), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and hydrolytic degradation test. FT-IR and 1H-NMR analyses show that the synthesized copolymers are the expected products; DSC test shows that with the increase of 1,3-BDO component, the melting point (Tm) gradually decreases from 158.24℃ to 104.19℃ and the glass transition temperature(Tg) gradually increases from 4.86℃ to 24.56℃, the synthesized copolyesters tend to be amorphous. TGA analyses indicate that the copolyesters have lower thermal stabilities with the increasing content of 1,3-BDO, but all the copolyesters still have good thermal stability, the initial decomposition temperatures are all higher than 310℃, so there is no need to use any heat stabilizer during the synthesis. The results of hydrolytic degradation tests indicate that the rates of degradation of copolyesters increase significantly with the higher ratio of 1,3-BDO component.
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