聚苯硫醚/有机蒙脱土复合材料热氧化研究

Thermal oxidation of polyphenylene sulfide/organic montmorillonite composites

以十六烷基三甲基溴化铵作为插层剂,采用阳离子交换法对钠基蒙脱土粉体进行有机改性制备有机蒙脱土(OMMT);采用熔融插层法制得聚苯硫醚(PPS)/OMMT复合材料并将复合材料进行热处理;利用红外光谱技术研究热处理前后PPS树脂及其复合材料的结构变化,对PPS的热氧化机理进行探讨;利用电脑测色配色仪对热处理前后的PPS树脂及其复合材料颜色的变化值进行测试。结果表明:与纯PPS树脂相比,OMMT的添加可以在一定程度上提高PPS树脂的抗氧化性;经过热处理后PPS树脂及PPS/OMMT复合材料均发生不同程度的氧化,苯环上发生交联,C—S键上发生氧化;C—H的面外弯曲振动峰及苯环C—O伸缩振动峰均发生蓝移;PPS/OMMT复合材料的色度变化程度明显降低,其中添加质量分数为5%的OMMT的复合材料的抗氧化效果较好。

Na-montmorillonite （Na-MMT） was organically modified by cation exchange with cetyl trimethyl ammonium bromide as an intercalation agent to produce organic montmorillonite （OMMT）. Polyphenylene sulfide （PPS）/OMMT composites were prepared by melt intercalation method and was exposed to heat treatment. The structure change of PPS resin and composites was studied by infrared spectrometry before and after heat treatment. The thermal oxidation mechanism of PPS was discussed. The color change of PPS resin and composites was also tested with a computer color testing and matching instrument. The results showed that the oxidant resistance of PPS could be effectively improved by the addition of OMMT; the oxidation reaction occurred in different degree in PPS resin and composites during the heat treatment, resuhing in the crosslinking on benzene ring and oxida- tion on C--S bond; the blue shift was observed both in the benzene ring C--H out-of-plane bending vibration peak and benzene ring C--O stretching vibration peak ; the color change degree of PPS/OMMT composites was significantly reduced ; and the oxidation resistance of PPS/OMMT composites was fairly good while adding 5% OMMT by mass fraction.