超支化聚酯/聚对苯二甲酸乙二醇酯复合材料的结构与性能

以分别具有端羟基、端十六烷基和端苯基的超支化聚酯(HBP)对聚对苯二甲酸乙二醇酯(PET)进行共混改性,研究了HBP的端基类型和用量对HBP/PET复合材料拉伸强度、冲击强度、结晶性能及动态黏弹性的影响。结果表明: 当端苯基超支化聚酯(HBP-Bz)、端十六烷基超支化聚酯(HBP-C16)和端羟基超支化聚酯(HBP-OH)的质量分数分别为0.1%、0.4%和0.2%时,HBP/PET复合材料的拉伸强度和冲击强度均达到最大值;3种超支化聚酯在其质量分数为0.1%~0.4%的范围内,复合材料的结晶度都得到了提高,与HBP-C16和HBP-OH相比,HBP-Bz的加入明显加快了PET的结晶速率;低用量(0.1wt%~0.4wt%)的HBP在PET共混改性中起到了增黏的效果,HBP/PET复合材料熔体表现出假塑性流体的流变行为,HBP的加入在一定程度上增加了PET大分子的链缠结和物理交联点,从而使HBP/PET复合材料的拉伸强度、冲击强度以及熔体黏度均得到提高。

Structure and properties of hyperbranched polyester/poly composites

Poly(ethylene terephthalate) (PET) was modified by blending with hyperbranched polyester (HBP) with terminal groups of hydroxyl, hexadecyl and phenyl.The effects of types and dosage of terminal groups of HBP on tensile strength, impact strength, crystallization and dynamic viscoelastic properties of HBP/PET composites were studied.The results show that when the mass fraction of phenyl-terminated HBP (HBP-Bz), hexadecyl-terminated HBP (HBP-C16) and hydroxyl-terminated HBP (HBP-OH) are 0.1%, 0.4% and 0.2%, respectively, the tensile strength and impact strength of HBP/PET composites reach the maximum.HBP improves the degree of crystallinity when the mass fraction of HBP is in the range of 0.1%-0.4%.Compared with HBP-C16 and HBP-OH, HBP-Bz dramatically accelerates the crystallization rate of PET.The lower mass fraction (0.1%-0.4%) of HBP plays a tackifying role in the blended systems of PET.HBP/PET composite melt exhibits the rheological behavior of typical pseudoplastic fluids.To some extent, the addition of HBP increases the macromolecular chain entanglement and physical junction of PET, and the tensile strength, impact strength and melt viscosity of HBP/PET composites are improved.