【作者】 余娟；

【导师】 戚嵘嵘；

【作者基本信息】 上海交通大学 ， 材料学， 2010， 硕士

【摘要】 目前,对现有高分子材料进行改性以获得综合性能优良的聚合物新材料是高分子材料科学研究的重要课题之一。聚对苯二甲酸丁二醇酯(PBT)作为一种重要的热塑性工程塑料,广泛应用在汽车、电子、电器等行业。它具有高的结晶速率,良好的耐化学药品性以及优异的加工性能。但纯的PBT缺口冲击强度低,限制了其应用范围。因此,PBT的增韧改性是必要的。本文采用热塑性弹性体对PBT进行增韧改性,以获得韧性较好的PBT材料。本文主要以聚对苯二甲酸丁二醇酯(PBT)、乙烯基热塑性弹性体(V-TPE)和聚醚性热塑性弹性体(TPEE)为原料,采用双螺杆挤出机进行熔融共混,分别制备了PBT/V-TPE和PBT/TPEE复合材料,系统地研究了PBT与不同热塑性弹性体共混材料的力学性能、流变性能以及热性能。结果表明,乙烯基热塑性弹性体都对PBT具有一定的增韧效果。乙烯-丙烯酸甲酯共聚物(EMA)对PBT的增韧效果优于乙烯-乙酸乙烯酯共聚物(EVA),但是当EMA的含量超过30份时,PBT/EMA复合材料由于出口胀大而难于挤出加工,而EVA的含量超过35份时其挤出加工性能也开始降低。而将EVA和EMA以一定比例复合使用时,复合材料的相容性有所提高,同时又能够提高复合材料的加工性能。此外,我们在PBT/EVA=65/35的组分中加入0.5phr三羟甲基丙烷三丙烯酸酯(TMPTA)后,复合材料的相容性也有所提高。从力学性能可以看到,聚醚型热塑性弹性体和PBT具有较好的相容性,复合材料具有较好的韧性。研究还发现TPEE可以作为PBT的成核剂,能适当地提高PBT的结晶度,但TPEE的复数粘度对温度较敏感,因此对加工温度的稳定性要求很高,导致加工过程变得困难。当在PBT/TPEE复合材料中加入环氧树脂时,发现复合材料的冲击强度会进一步提高,而且环氧树脂的加入,使两相界面变得模糊,分散相尺寸减小,说明环氧树脂可以提高PBT和TPEE的相容性,但使PBT的结晶度有所降低。更多还原

【Abstract】 Poly (butylene terephthalate) (PBT) is an important engineering thermoplastic which has been widely used in automobile, electron, electronic appliance and so on due to its good properties like high rate of crystallization, solvent resistance and excellent processing. But its low impact strength at room temperature restricts its application in wider areas. In order to improve its toughness, in this work, different thermoplastic elastomers are used to toughening modify the PBT.In this study, PBT/Vinyl Thermoplastic Elastomer (V-TPE) and PBT/Thermoplastic polyether elastomer (TPEE) composites are prepared through a twin-screw extruder by the way of melting extruding. The effect of V-TPE, TPEE, compatibilizers and their content on mechanical properties, morphology, rheological behavior and thermal properties of the composites are studied in detail.The results show that both ethylene-vinyl acetate copolymer (EVA) and ethylene-methyl acrylate copolymer (EMA) increase the notched impact strength increases, and EMA is better than EVA. Moreover, combining EVA with EMA is developed to improve the comprehensive properties of PBT. In addition, the addition of TMPTA can improve the compatibility between PBT and EVA.PBT/TPEE composites have good toughness, and the crystallinity of PBT can be improved with the addition of TPEE. While the complex viscosity of TPEE is so sensitive to the temperature that makes the extrusion processing become different. Epoxy can improve the compatibility between PBT and TPEE so that PBT/TPEE composites have good toughness.更多还原