摘要
采用模压成型法和滚塑成型法制备了交联聚乙烯样品,研究了成型方法对样品不同温度时的落锤冲击强度以及厚度梯度方向的晶体尺寸、结晶度以及交联度等微观结构的影响。结果表明,测试温度由25℃降低到-40℃时,模压成型样品的落锤冲击强度由29J/mm提高到35J/mm,不同厚度梯度上的微观结构基本相同;滚塑成型样品的测试温度为25^-20℃时,落锤冲击强度约为29J/mm,测试温度为-30^-40℃时,落锤冲击强度为1J/mm,样品测试温度由-20℃降低到-30℃时发生韧性-脆性转变,除最内层(约0.2mm)样品,不同厚度梯度的微观结构基本相同,最内层样品的凝胶含量较低,结晶度和球晶尺寸较大,最内层制品的结构是影响低温落锤冲击性能的关键因素。
In this work, crosslinked polyethylene samples were prepared by compression molding and rotational molding methods, and then effects of molding methods on dropweight impact strength at different temperature, crystal size, crystallinity degree and gel content at different thickness gradients of crosslinked polyethylene were investigated. The results indicated that the dropweight impact strength of the compressionmolded sample increases from 29 J/mm to 35 J/mm when test temperature was reduced from 25 ℃ to -40 ℃, but the sample kept an identical microstructure in different gradient thicknesses. For the rotational molded sample, the dropweight impact strength at -20~25 ℃ and -40^-30 ℃ is about 29 and 1 J/mm, respectively. There is a ductilebrittle transition between -20 and -30 ℃, and the microstructures also kept an identical microstructure in different gradient thicknesses except for the innermost surface layer around 0.2 mm. The inner surface layer has a lower gel content, higher crystal size and higher crystallization degree in comparison with other gradient thicknesses. Moreover, the microstructures of the innermost surface layer dominated the dropweight impact performance at low temperature.
出处
《中国塑料》
CSCD
北大核心
2017年第10期83-88,共6页
China Plastics
关键词
模压成型
滚塑成型
交联聚乙烯
微观结构
compression molding
rotational molding
crosslinked polyethylene
microstructures
