氧化镧对硅烷交联PE-LLD热性能的影响

Effects of Lanthanum Oxide on Thermal Behavior of Silane Crosslinked PE-LLD

通过热失重分析、示差扫描量热分析、氧化诱导期和维卡软化点测定等手段研究了稀土化合物氧化镧 (La2O3)对硅烷交联线形低密度聚乙烯(PE-SXLLD)热性能的影响。研究结果发现,添加La2O3可极大地提高PE- SXLLD的热氧分解温度,但对其热裂解分解温度却没有影响,其作用机理可能是La2O3的存在减缓了氧分子在PE- SXLLD交联结构中的扩散运动,从而延缓了PE-SXLLD交联结构的链断裂反应。添加La2O3对PE-SXLLD的结晶熔融行为影响不大,也没有改变PE-SXLLD的凝胶率和热变形行为。

The effect of La2O3 on the thermal behavior of silane crosslinked PE-LLD （PE-SXLLD） was investigated through thermogravimetric analysis （TGA）, differential scanning calorimetry （DSC）, and oxidation induction time （O. I. T） and Vicar softening point measurements. It has been found that the thermal oxidation degradation temperature of PE-SXLLD could be remarkably increased by the addition of La2O3, while the thermal degradation temperature remained unchanged. The possible reason could be that the diffusion movement of oxygen molecules was slowed down by the coupling of La2O3 with oxygen, so that the main chain scission reaction of PE-SXLLD was hindered. The crystallization and melting behavior of PE-SXLLD were almost not altered by the addition of La2O3, Vicar softening point and gel content of PE-SXLLD were also not affected.