Morphology and mechanical properties of foamed polyethylene-polypropylene blends
Morphology and mechanical properties of foamed polyethylene-polypropylene blends
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DOI：
10.1177/0021955x05056959
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发表时间：
2005-09-01
影响因子：
2.5
通讯作者：
Rodrigue, Denis
中科院分区：
文献类型：
--
作者：
Herrera Tejeda, Elias;Zepeda Sahagun, Carlos;Rodrigue, Denis
以偶氮二甲酰胺为发泡剂，采用挤出发泡法对高密度聚乙烯（HDPE）和聚丙烯（PP）共混物进行发泡，研究共混对共混物形态结构和力学性能的影响。在0.5wt%的发泡剂下，发现对于每种共混组合物，最佳泡沫密度为约417 kg/m3，但平均泡孔尺寸范围在130和301 μ m之间，这取决于共混组合物。据信，分散的聚合物相充当成核位点，产生具有较小泡孔尺寸的泡沫。由于两种聚合物之间的不相容性，纯聚合物获得了最佳的拉伸和冲击性能。提出了简单的半经验模型来预测泡沫的拉伸和冲击性能。
Blends of high-density polyethylene and polypropylene are foamed by means of extrusion using azodicarbonamide as a chemical blowing agent to study the effect of blending on the morphological and mechanical properties. At 0.5 wt% of blowing agent, optimum foam density is found to be around 417 kg/m(3) for each blend composition, but the average cell size ranges between 130 and 301 mu m depending on the blend composition. It is believed that the dispersed polymer phase acts as nucleating sites producing foams with smaller cell sizes. Owing to the incompatibility between both the polymers, the best tensile and impact properties are obtained for neat polymers. Simple semi-empirical models are proposed to predict the tensile and impact properties of the foams.