PP化学降解中助剂、温度和分子量的影响

THE EFFECTS OF AUXILIARY TEMPERATURE AND MOLECULAR WEIGHT IN CHEMICAL DEGRADATION OF PP

用直接化学降解法讨论ＰＰ化学降解过程中的添加剂、加工温度和原始分子量对ＰＰ熔体流动性变化的影响。结果表明：ＰＰ中添加的少量防紫外与抗热氧老化阵解等助剂对化学降解剂如过氧化物二叔丁基（ＤＴＢＰ）等活性反应基团有一定的抑制作用。加工温度选择是有效利用化学阵解剂来改善ＰＰ熔体流动性的重要条件之一，同时ＰＰ分子链与化学活性基团的降解现象是有温度依赖性的。另外，在相同的化学降解条件下，不同原始分子量ＰＰ熔体流动性变化有较大的差别。

The effects of the additive,process temperature and initial molecular weight etc. on the melt flowing abilityof PP are discussed.The experiment results show that the active reaction groups in chemical degradation canbe restrained by a little auxiliaries of ultraviolet resistant, heatproof antioxdant and antiager etc. which addedin PP. The process temperature is an imprortant condition for using chemical degradation agent efficiently toimprove melt flow ability of PP,the degradation of molecular chains of PP and active reaction groups are de-pendent on the temperature. On the other hand,the melt flow ability of different initial molecular weights ofPP have larger difference at the same chemical degradation condition.