聚氯乙烯树脂的不饱和度和热稳定性的关系

STUDIES ON THE RELATIONSHIP BETWEEN THE UNSATURATION AND THERMAL STABILITY OF POLYVINYL CHLORIDE

用紫外可见光谱法表征了不同来源的聚氯乙烯树脂（ＰＶＣ）的热稳定性，用一氯化碘加成法测量了ＰＶＣ的总的双键含量，用红外光谱法测量了ＰＶＣ的孤立双键和共轭双键的相对含量．结果表明，ＰＶＣ在加工期间的初期着色行为和长期热稳定性并不直接相关，前者取决于ＰＶＣ分子链中共轭双键的含量。

The integrated areas of UV visible absorption in 350～700 nm region have been used to characterize the thermal stability of PVC samples.The integrated absorbance of IR bands at 1667 cm -1 and 1650～1560 cm -1 have been used to measure the contents of isolated double bonds and conjugated polyene of PVC samples respectively. The results indicates that the coloration during the initial thermal degradation stage of PVC is dependent on the contents of conjugated polyene and the coloration during long term thermal degradation is related to the contents of isolated double bonds.