sPS/PET/SsPS-H共混体系的研究

Study on sPS/PET/SsPS-H Blends

以自制间规聚苯乙烯 (sPS)功能化合成的磺化间规聚苯乙烯 (SsPS H)作相容剂 ,研究其对sPS/PET共混物微相结构与性能的影响 ,发现SsPS -H能够有效地改善二者的相容性 ,当sPS/PET/SsPS H为85 /15 /2 (重量比 )时 ,冲击强度达到 11.4kJ/m2 ,为纯sPS的 3倍 ,此时材料的弯曲强度为 39.1MPa ,下降约8% ;DMA结果表明 ,随SsPS H用量的增加 ,共混物的Tg 逐渐提高 ;DSC分析结果表明 ,共混体系中sPS的熔点不受SsPS H含量的影响 ,而PET的熔点在加入 6份SsPS H时明显降低。sPS在达到最大结晶速率时的温度均随SsPS H用量的增加先提高而后下降。SEM观察到加入SsPS H后 ,PET分散相的尺寸减小 ,且均匀程度增加 ,共混物室温下冲击断裂显著地由脆性转变为韧性 ,当加入 6份SsPS H后 。

The mechanical properties and morphology of syndiotactic polystyrene (sPS)/ polyester (PET)/sulfonated syndiotactic polystyrene (SsPS H) blends have been investigated. It showed that SsPS H was an effective compatibilizer and toughener for sPS/PET blend. When sPS/PET/SsPS H = 85/15/2(weight ratio), the unnotched Izod impact strength of blends reached maximum value of 11.4 kJ/m 2, which was about 3 times of the pure sPS, while flexural strength was 39.1 MPa, decreasing about 8% compared with pure sPS. The glass transition temperature (T g) of blends was higher than that of pure sPS. The melting temperature (T m1 ) of sPS of blends was not changed with increasing content of SsPS H, while that of PET (T m2 ) was lower than that of pure PET as addition of 6 parts SsPS H. Moreover, the temperature at maximum crystallization velocity of sPS (T p1 ) was both improved with addition of lower content of SsPS H. The sPS/PET/SsPS H SEM micrographs displayed the size of PET particles was decreased and the phase distribution became more evenly. The blends exhibit toughened fracture surface as compared with the PET/sPS blends.