滚塑成型工艺对交联高密度聚乙烯低温冲击性能的影响

摘要

The effects of processing parameters on the drop-weight impact strength (ARM and microstructures of rotation molded crosslinked high density polyethylene (XLPE) were investigated.When the peak inner air temperature (PIAT) during rotational molding is 212 ℃ or lower,the ARM impact strength at-40 ℃ of the molded article is about 1 J/mm and the specimens break in brittle failure mode.However,when PIAT is between 228 ℃ and 263 ℃,the specimens exhibit ductile fracture and the ARM impact strength at-40 ℃ is about 30 J/mm.By optimizing the processing conditions,high crosslink density and lower crystallinity of the innermost surface layer can be attained,and the articles obtain enhanced low temperature impact strength.%采用滚塑成型方法,研究了加工条件对交联高密度聚乙烯(XLPE)制品低温落锤冲击性能和微观结构的影响.结果表明,滚塑模具内部空气最高温度(PIAT)对XLPE的-40℃的冲击强度影响大,PIAT为212℃时,-40℃的冲击强度约1 J/mm,为脆性破坏,PIAT在228 ～263℃时,-40℃冲击强度基本没有变化,约为30 J/mm,为韧性破坏;非等温交联动力学以及交联和结晶数据分析表明,通过优化加工条件,使制品最内层充分交联进而获得较高的交联度,较低的结晶度,获得优异的低温落锤冲击强度.