超临界CO_2对UHMWPE/HDPE共混过程的影响  

Effects of CO_2 Supercritical Fluid on the Blending of UHMWPE/HDPE

作　　者：向洁然 谢邦互[1] 杨伟[1] 杨鸣波[1] 

机构地区：[1]四川大学高分子科学与工程学院,四川成都610065

出　　处：《塑料工业》2017年第2期88-92,共5页China Plastics Industry

摘　　要：通过改进的耐高压力的密炼机,在170℃,通入超临界CO_2流体至约8 MPa,对超高摩尔质量聚乙烯(UHMWPE)颗粒和高密度聚乙烯(HDPE)混合物进行了约20 min的熔融共混,并将UHMWPE质量分数为2%、4%、6%、8%、10%的UHMWPE/HDPE共混物与未通超临界流体的熔融共混物对比,以考察和了解超临界流体对体系扩散行为等的影响。差示扫描量热仪结果显示,超临界CO_2流体使共混物的熔点升高、结晶度增大、结晶峰温度略有上升;旋转流变仪结果显示,超临界CO_2流体使共混物熔体的复数黏度明显下降,损耗角正切明显降低并在低频区易于出现明显平台。The ultra-high molecular weight polyethylene （UHMWPE） and high density polyethylene （HDPE） were blended by using the torque mixer under the atmosphere of supercritical carbon dioxide in this article, and the influence of supercritical carbon dioxide （SC-CO2 ） on mutual diffusion of the two phases was studied. Differential scanning calorimeter （DSC） and rotational rheometer were used to characterize the crystallization and rheology behaviors of the UHMWPE/HDPE blends with different weight ration. The results presente that the sample treated by SC-CO2 owns higher melting point and degree crystallinity compared to the conventional sample; in addition, for the sample treated by SC-CO2, the complex viscosity and loss tangent obviously decreases. The platform is earlier to appear in low frequency than conventional ones. At the same time, some reasons and supposition were given for the phenomena.

关 键 词：超高摩尔质量聚乙烯 高密度聚乙烯 超临界CO2 相互扩散 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]