聚苯醚/聚对苯二甲酸丁二醇酯合金的增容改性研究

Study on the Compatibility of Poly(phenylene oxide)/PBT Alloy

分别以苯乙烯-马来酸酐共聚物(SMA)、乙烯-醋酸乙烯酯共聚物(EVA)、乙烯-丙烯酸甲酯共聚物(EMA)和聚苯乙烯-氢化丁二烯-苯乙烯接枝马来酸酐为增容剂,通过双螺杆挤出机熔融共混制备了一系列聚苯醚/聚对苯二甲酸丁二醇酯(PPO/PBT)合金。通过扫描电子显微镜、透射电子显微镜、动态机械分析、万能拉伸试验、简支梁冲击试验以及高压毛细管流变仪等,对合金的"金相结构"、相容性、力学性能以及加工流动性等进行了研究。结果表明,无增容剂的PPO/PBT合金断面光滑,分散相PPO的微粒尺寸较大、且有明显的团聚现象,力学性能差。加入增容剂后,PPO微粒尺寸均有下降,断面粗糙度提高,相容性得到改善。特别是加入SMA后,分散相的PPO微区尺寸明显降低——由原来的1μm降低至250 nm左右,基本无团聚现象,体系相容性提高最明显,合金的拉伸强度提高了60%,冲击强度提高了75%,合金中PBT的玻璃化转变温度提高幅度也最大,由70℃提高到了80℃。高压毛细管实验结果表明,加入PBT可显著改善PPO的加工流动性。

A variety of poly （phenylene oxide）/polybutylene terephthalate （PPO/PBT） alloys with different compatibilizers were prepared by melt blending using a twin-screw extruder. The metallographic structure, compatibility, mechanical properties and processing flow performance of the alloys were investigated by scanning electron microscopy （ SEM）, transmission electron microscopy （ TEM）, dynamic mechanical analysis （DMA）, tensile testing, simple beam impact testing and high pressure capillary rheometer. The results demonstrated that the alloys without the compatibilizer exhibit quite smooth cross- sectional, the size of the dispersed phase （PPO） was larger and the mechanical properties were poor. However, after incorporated with the compatibilizers, the size of the dispersed phase （PPO） was reduced and the cross-sectional roughness of alloys was also improved, indicating the good compatibility. In particular, after adding styrene-maleic anhydride copolymer （ SMA）, the size of the dispersed phase （PPO） was significantly reduced from 1μm to about 250 nm and the agglomeration was also disappeared. Moreover, the glass transition temperature of PBT increased from 70℃ to 80℃, the tensile strength and impact strength were increased by 60% and 75%, respectively. The results of high pressure capillary experiments show that the addition of PBT significantly improves the processing flow of PPO.