1,2-丁二醇共聚对聚对苯二甲酸乙二醇酯结晶行为及力学性能的影响

为了探索生物基乙二醇中的1,2-丁二醇(1,2-BDO)作为共聚单体对生物基聚对苯二甲酸乙二醇酯(PET)的结晶行为和力学性能的影响。本文合成了生物基PET均聚物和不同1,2-BDO共聚单元摩尔分数的系列生物基PET共聚物(共聚单体摩尔分数分别为2. 0%、2. 7%和5. 6%),并采用傅里叶变换红外光谱仪(FTIR)、差示扫描量热仪(DSC)和力学测试等技术手段研究了其结晶行为和力学性能。结果表明,随着1,2-BDO共聚单元摩尔分数的增加,PET共聚物的熔融温度、结晶速率及结晶度均明显降低,表明1,2-BDO共聚单体的引入破坏了PET分子链的规整性,阻碍了PET链段的结晶。PET材料的拉伸强度随着1,2-BDO共聚单元摩尔分数的增加而降低,而弯曲强度和弯曲模量略有升高。

Effects of 1,2-Butanediol Comonomer on the Crystallization Behavior and Mechanical Properties of Poly(ethylene terephthalate)

In this work, poly(ethylene terephthalate)(PET) homopolymer and copolymers were synthesized from biomass-derived ethylene glycol containing 0, 2.0%, 2.7%, and 5.6% mole fraction of 1,2-butanediol(1,2-BDO) in order to explore the effects of the comonomer on the crystallization behavior and the mechanical properties of the PET. The polymers were investigated by Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC), and mechanical testing. It is found that the melting temperature, crystallization rate and crystallinity of the PET decrease as mole fraction of 1,2-BDO comonomer increases, indicating that the incorporation of the 1,2-BDO units can disrupt the ordered structure of the PET chains and therefore hinder the crystallization. In addition, the tensile strength of PET materials decreases while the flexural modulus and strength increase slightly at higher 1,2-BDO mole fraction.