网络结构对多层聚乙烯共混物界面扩散行为的影响  

INFLUENCE OF NETWORK ON THE INTERFACIAL DIFFUSION OF MULTILAYER POLYETHYLENE BLENDS

作　　者：李文林[1] 牛艳华[2] 王志刚[1] 张军[2] 

机构地区：[1]中国科学院软物质化学重点实验室、中国科学技术大学高分子科学与工程系,合肥230026 [2]中国科学院化学研究所、工程塑料中科院重点实验室,北京100090

出　　处：《高分子学报》2012年第9期1007-1014,共8页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号50803073);国家重点基础研究发展计划(973计划;项目号2012CB025901)资助

摘　　要：通过溶液法制备超高分子量聚乙烯(UHMWPE)/乙烯-己烯共聚物(PEH)共混物,采用动态流变学方法研究了UHMWPE/PEH共混物多层膜在熔点以上的界面扩散行为,结合Double-Reptation理论计算得到了UHMWPE/PEH共混物多层膜的自扩散系数.研究表明UHMWPE在浓度c=1.0 wt%以上可以在PEH基体中形成网络结构.UHMWPE/PEH共混物多层膜界面扩散不符合严格的菲克扩散定律,扩散系数具有时间依赖性.扩散曲线显示扩散过程在到达平台值之前分为2个区域,区域I接近于菲克扩散;然而由于引入UHMWPE,区域II扩散显著偏离菲克扩散行为,特别是当UHMWPE在PEH基体中形成网络结构以后,偏离菲克扩散行为更加显著.Ultrahigh molecular mass polyethylene（UHMWPE） and statistical copolymer of ethylene and 1-hexene（PEH） were used to prepare UHMWPE/PEH blends with relatively low UHMWPE concentrations.UHMWPE forms network structure in the blends with UHMWPE concentrations above a critical value of c=1 wt%.The influence of the formed UHMWPE network on the interfacial diffusion behaviors of multilayer UHMWPE/PEH blends was investigated by applying small oscillatory shear rheology.The interfacial diffusion coefficients of multilayer UHMWPE/PEH blends were obtained from the rheological data.It is found that the diffusion coefficients are time-dependent and two diffusion regions are distinct before the diffusion reaches the plateaus according to the changes of diffusion exponent n in the relation of D-t n,which implies an approximate Fickian diffusion behavior in region Ⅰ（c 1.0 wt%） and an obvious deviation from the Fickian diffusion behavior in region Ⅱ（c1.0 wt%）.With the formation of UHMWPE network in the UHMWPE/PEH blends,deviation from the Fickian behavior for diffusion of multilayer UHMWPE/PEH blends becomes significant.The above results help facilitate the industrial processing of multilayer polyolefins,which is related to the interfacial diffusion.

关 键 词：聚乙烯共混物 网络结构 界面扩散 流变学 

分 类 号：O632.12[理学—高分子化学]