优化聚氯乙烯树脂中弱结构与热氧光氧稳定性的研究

【作者】 王桂花；

【导师】 张美珍； 杨屹；

【作者基本信息】 北京化工大学 ， 应用化学， 2000， 硕士

【摘要】 本文应用傅立叶变换红外光谱仪、紫外分光光度计对聚氯乙烯中存在的弱结构，过氧结构以及碳-碳双键结构等进行了研究；用催化溴加成法测定了优化前后的PVC树脂总双键的含量，并对热氧老化的PVC树脂中总双键含量的变化进行了研究；采用电位滴定法对聚氯乙烯中的烯丙基氯进行了测定，并研究了烯丙基氯的含量与相对分子质量之间的关系：使用白度仪测定了聚氯乙烯的白度降，研究了聚氯乙烯的初期着色性能；通过热重分析仪研究了聚氯乙烯的脱氯化氢的速度，进一步探讨了聚氯乙烯的热稳定性。 本文用红外热跟踪法、紫外线辐照法对同一厂家的优化前、优化中、优化后的聚氯乙烯树脂进行了热氧与光氧稳定性的研究并与不同厂家的对照样进行了对比，结果证明聚氯乙烯的热稳定性随着聚氯乙烯中弱结构含量的增加而变差，并由此比较出了优化前后PVC树脂热稳定性的差异。 本文还应用白度仪测定了同一厂家的优化前、优化中、优化后的聚氯乙烯树脂及不同厂家的对照样的白度降，结果表明全面优化后的样品，其白度降最小，初期着色性最佳，初期着色性与PVC链的立构有关。更多还原

【Abstract】 In this paper, structural defects of PVC, such as peroxide groups, carbonyl groups and carbon-carbon double bonds, were investigated by means of FTIR, UV-Visible spectra. The total double bond contents of PVC before and after optimization were determined by analytical method of cataltic bromine addition and changes of the total double bond contents of products obtained after thermal oxidation of PVC were studied. The chloroallyl group contents of PVC were determined by potentiometric titration and the correlation between chloroallyl group content and molecular weight was studied. The white degree dropping of PVC were tested by white degree meter. The rates of dehydrochlorination of PVC were studied by the thermogravimeter. Thermal stability of PVC were further explored.The thermo-oxidation and photo-oxidation stabilization of PVC samples optimized, optimizing and un-optimized from the same factory were studied by the heat following the track method of IR and UV radiation method. Then optimized samples were compared with the contrast samples. The results verified that the thermal stability of PVC decreased with the increase of structural defects contents of PVC . Thus the difference between optimized and un-optimized PVC samples had been investigated.At the same time, the white degree dropping of several samples were tested by white degree meter .The result showed that white degree dropping of all optimized samples were the lowest and the coloured property during the initial heating was the best. The property related to the stereospecific structure of PVC chain.更多还原