【摘要】 通过熔融共混的方式,将实验室自行设计合成的三元共聚热致液晶聚酯酰亚胺(PPDI)与聚对苯二甲酸乙二酯(PET)进行共混,制备一系列不同液晶聚合物含量的共混体系.采用示差扫描量热仪(DSC)、广角X-射线衍射仪(WAXD)和动态力学性能分析仪(DMA)对共混体系的结构与性能进行表征.结果表明,共混体系中两组份之间具有良好的相容性,表现出单一的玻璃化转变温度,且玻璃化转变温度明显高于基于Fox方程的理论计算值;液晶聚合物的加入对PET的结晶行为及结晶结构产生重要的影响,起到了明显的异相成核作用,大大提高了PET的结晶温度及结晶速率,并有利于其结晶度和结晶完善程度的提高和改善;PPDI对共混体系起到了显著的增强效果,体现为体系储能模量的提高,且其储能模量随着PPDI添加量的增加而增加;液晶PPDI的加入对共混体系的热稳定性影响不大,其起始分解温度较基体PET略有提高.更多还原

【Abstract】 The effects of terpolymer liquid crystalline poly(ester imide)(PPDI) on the structure and properties of its blend with semicrystalline polymer,poly(ethylene terephthalate)(PET) were studied.The PPDI was synthesized by our lab.The blend systems were prepared by melt blendinga,nd the content of PPDI ranged from 0 /100 to 10 /90.Differential scanning calorimetry(DSC),wide-angle X-ray diffraction(WAXD) and dynamic mechanical property analysis(DMA) were used to study the crystalline behavior,crystalline structure and dynamic mechanical properties of the blend system,as well as the miscibility of PPDI and PET.Results showed that the addiction of liquid crystalline terpolymer PPDI had strong effect on the crystalline behavior and crystalline structure of PET,which acted as heterogeneous nuclear agentst,herefore increasing the initial crystallization point and crystallization rate of PET,and was of benefit to the increase of the degree of crystallinity and the perfection of crystallization.The blend systems show only one glass transition temperature(Tg),and the Tgs are much higher than the theoretical results calculated by using Fox equation.Dynamic mechanical properties showed that storage modulus of the blend systems was higher than that of PET,and increased with the content of PPDI.These mean that PPDI has a reinforcing effect on PET.The thermal stability of the blend systems is a little higher than that of pure PET.更多还原