PET/PBT合金的熔融共混及性能

The Melt Blending and Properties of PET/PBT Alloy

论述了PET/PBT合金的熔融共混理论,包括两种材料熔融共混过程中的相容性、结晶性及酯交换反应:PET/PBT共混体系在非晶区是相容的;加工工艺对共混体系的结晶度影响很大,PET和PBT共混对其结晶过程具有协同效应,可在成型加工时添加成核体系以促进其结晶;酯交换反应会使体系的结晶能力下降。简要讨论了合金的机械性能及不同因素对其影响:合金硬度受体系分子量和淬火时冷却速率的影响,增强合金的弯曲强度可填充改性无机填充剂,合金的缺口敏感性强,缺口冲击强度较低,所以冲击改性常被作为其重要研究对象。PET/PBT合金作为一种工程塑料,现阶段主要应用于汽车领域,未来将在电子电器、机械工业和汽车零部件等领域有着更广泛的应用。

The melt blending theory of PET/PBT alloy is discussed, which includes compatibility, crystallization and transesterification during the melt blending process of the two materials. The melt blending system of PET/PBT is miscible in the amorphous area, and the producing process has great influence on its crystallinity. Because of the synergistic effect on the crystallization process of PET and PBT blending, adding nucleation system can promote crystallization during moulding and processing phases while the transesterification decreases the probability of crystallization. The mechanical properties of the alloy and their influencing factors are researched. The hardness of the alloy is affected by the molecular weight and the cooling rate when quenching, its flexural strength can be improved through filling inorganic filler. The alloy has strong notch sensitivity and small notched impact strength, therefore impact modification is always considered the most important research subject. As a kind of engineering plastics, the PET/PBT alloy is mainly applied in the automobile area at present, and has good prospects in the applications in electronics, mechanical industry and automobile parts.