滚塑用聚乙烯树脂冲击性能及评价方法研究

STUDY ON IMPACT PROPERTY AND EVALUATIONMETHOD FOR THE ROTATIONAL POLYETHYLENE RESINS

筛选国内外6种典型滚塑聚乙烯样品,通过注塑和压塑2种制备工艺,对其进行简支梁缺口冲击和落锤冲击性能评价。研究发现,滚塑料的冲击性能与树脂的分子结构、共聚单体分布及种类密切相关;同一类型催化剂,MFR越低,滚塑料冲击强度越高;使用共聚单体碳链越长,滚塑料冲击强度越高;不同催化剂中的茂金属催化剂生产的滚塑料,冲击强度较高。2种压制工艺的研究结果表明:注塑片材的落锤冲击强度比压塑片材落锤冲击强度偏低,注塑样条的简支梁缺口冲击强度明显高于压塑样条。

Six typical rotational polyethylene resins were selected in this paper.The Charpy notched impact strengt hand the drop hammer impact strength were tested on the previous mentioned six resins by two different sample preparation-injectionand compressionmolding methods.The study results in this paper showed that impact property of the rotational polyethylene resins was closely related to molecular structure,comonome rdistribution and type.For the rotational polyethylene resins produced by the same type of catalyst,the lower MFR,the higher impact strength.The longer carbon chain of comonomer,the higher impact strength.For the rotational polyethylene resins produced by different catalysts,the resin made by the metallocene catalyst would have higher impact strength.The two different sample preparation methods study results showed that the drop hammer impact strength of the sample sheet prepared by compression molding was higher than that of the sample prepared by injection molding,the Charpy notched impact strength of the sample prepared by injection molding was higher than that of the sample prepared by compression molding.