HDPE/LDPE复合交联物的热降解研究

采用热重分析仪（TG）考察了高密度聚乙烯（HDPE）／低密度聚乙烯（LDPE）复合交联物的热稳定性。结果显示，HDPE／LDPE复合交联物的热稳定性低于HDPE／LDPE共混物。FTIR分析证实，交联反应使聚乙烯（PE）的支化程度提高，取代基的位阻效应在一定程度上影响了PE的热降解过程。在N2气氛下，HDPE／LDPE共混物及交联物的热降解过程均为一步降解反应。Kissinger法求解HDPE／LDPE共混物及其复合交联物的热降解活化能发现，LDPE质量分数在20％～30％之间变化时，HDPE／LDPE交联物的热降解过程对温度的敏感性发生了突变。

Study on Thermal Degradation of HDPE/LDPE Crosslinked Product

The thermal stability of HDPE/LDPE crosslinked product was studied by means of thermogravimetric analysis(TGA).The results showed that the thermal stability of HDPE/LDPE crosslinked product was poorer than that of HDPE/LDPE blend. The result of FTIR analysis informed that the branch concentration of the crosslinked PE was increased significantly by crosslinking reaction, their substituted alkyl groups would subsequently effect the whole degradation of the crosslinked PE. Furthermore, it was found that the thermal degradation reactions for HDPE/LDPE blend and HDPE/LDPE crosslinked products were much more similar and both belong to one-step mechanism. It was also noticed that the sensitivity to temperature for the thermal stability of HDPE/LDPE crosslinked products was changed sharply while the amounts of LDPE changed from 20% to 30% in calculating the activated energy of the blend in thermal degradation by means of Kissinger method.