不同软硬段含量PBT-b-PTMG嵌段共聚物的合成与性能

Synthesis and Properties of PBT-b-PTMG Block Copolymers with Different Soft and Hard Segment Contents

采用直接酯化熔融缩聚法合成一系列不同软硬段含量的聚对苯二甲酸丁二醇酯(PBT)-b-聚四氢呋喃(PTMG)聚醚酯嵌段共聚物(TPEE),以红外光谱、核磁共振、X射线衍射、差示扫描量热分析和动态力学热分析等方法,探讨不同软硬段质量比及不同软段相对分子质量对材料结构及相对分子质量、热性能和黏弹性等的影响。结果表明,在相同出料功率下制得的TPEE的特性黏度均高于PBT,并随硬段质量分数或软段相对分子质量的增大而减小;TPEE的熔点下降幅度随软段摩尔分数的增加而增大;TPEE中存在微相分离结构,当硬段质量分数为60%、软段PTMG数均分子量为2×103时,同时出现了分别代表硬段PBT以及软段中PTMG的玻璃化转变的损耗角正切峰。研究结果为TPEE的合成和应用提供了一定借鉴。

A series of polybutylene terephthalate(PBT)-b-polytetrahydrofuran(PTMG)polyether ester block copolymers(TPEE)with different soft and hard segment contents were synthesized by direct esterification melt polycondensation.The effects of different soft and hard segment mass ratios and soft segment molecular weight on the structure,molecular weight,thermal properties and viscoelasticity of the materials were investigated by FT-IR,1H-NMR,XRD,DSC and DMA.The results show that the characteristic viscosity of TPEE is higher than that of PBT at the same discharge power,and decreases with the increase of the mass fraction of hard section or molecular weight of soft section;the decrease of its melting point increases with the increase of the molar fraction of soft section;the micro-phase separation structure exists in TPEE,when the mass fraction of hard section is 60%,and the number-average molecular weight of soft section is 2×10^(3),and the loss angle tangent peaks representing the glass transition of PBT in hard segment and PTMG in soft segment respectively appear.The results of the study provide some reference for the synthesis and application of TPEE.