交替微层高分子复合材料的阻隔性能与结构

Barrier Property and Structure of Alternating Microlayered Composites

利用实验室自行设计制造的微层共挤出装置制备了2种交替层状高分子阻隔材料,即HDPE/PA6和PP/(EVOH+PP)。对于HDPE/PA6样品,连续的HDPE和PA6层沿挤出方向交替排列,PA6作为阻隔材料分布于HDPE层间,是一种理想的串联多层板形态,串联分布的方向与非极性小分子的渗透方向垂直。也就是说小分子在该材料中渗透时必然经过每层PA6,从而提高材料的阻隔性能。对于PP/(EVOH+PP),随着层数的增加,EVOH在PP基体中的分散形态由零维球形变为一维纤维状,进而演变为二维片状。这些形态导致小分子气体在材料中的渗透路径变长,从而材料的氮气渗透系数大幅度降低。相容剂含量和层数对交替微层高分子复合材料阻隔性能的影响同时被研究。

Two barrier materials,HDPE/PA6 and PP/（EVOH＋PP）,were prepared by the microlayered coextrusion device designed in our laboratory.For HDPE/PA6 sample,the continuous HDPE and PA6 layers wer arranged alternately along the extrusion direction.Therefore,the nonpolar small molecules always penetrated through the every PA6 layer,the permeability coefficient of which was very low.This led to an improved barrier property of microlayered HDPE/PA6.For PP/（EVOH＋PP）,the morphology of EVOH phase in PP matrix was changed from zero-dimensional sphere to one-dimensional fiber, then to two-dimensional sheet with the increase of layer number, which caused significant improving of barrier property. The effects of compatible content and layer number on barrier property of alternating microlayered composites were also researched.