3种注塑专用高密度聚乙烯树脂的性能对比

采用凝胶渗透色谱、差示扫描量热等方法分析测试了3种注塑专用高密度聚乙烯树脂(HDPE,进口2种,国产1种)的分子结构及物理机械性能。结果表明,HDPE的相对分子质量分布、密度、支化度、支化类型、拉伸屈服强度、断裂伸长率、冲击强度、弯曲弹性模量、熔点、热变形温度和维卡软化点、氧化诱导期、耐环境应力开裂时间分别为:(1)国产,5.36,951.9 kg/m3,4.1,乙基支化,26.5 MPa,1 100%,98.6 J/m2,1 160 MPa,131.1℃,76.9℃,127℃,28 min,18 h;(2)进口,4.95～5.05,949.0 kg/m3,3.9～6.8,甲基支化,24.5～25.1 MPa,598%～950%,88.6～123.8 J/m2,762～825 MPa,132.6～132.9℃,77.1～77.2℃,126～126℃,14～18 min,10～37 h。

Comparative study on properties of three types of injection specialty high density polyethylene resin

The properties,such as molecular structure,mechanical properties,were analyzed and measured for three types of injection specialty high density polyethylene（HDPE） resin including two imported and one home-made products by gel permeation chromatography and differential scanning calorimetry etc.The results showed that the molecular weight distribution,density,branching type and its degree,yield strength,elongation at break,impact strength,bending modulus,melt temperature and vicat softening point,oxidation induction time and environmental stress cracking time were 5.36,951.9kg/m3,4.1,ethyl branching,26.5MPa,1100%,98.6J/m2,1160MPa,131.1℃,76.9℃,127℃,28min,18h respectively for home-made resin sample,and 4.95-5.05,949.0kg/m3,3.9-6.8,methyl branching,24.5-25.1MPa,598%-950%,88.6-123.8J/m2,762-825MPa,132.6-132.9℃,77.1-77.2℃,126℃,14-18min,10-37h for imported resin samples.