采用微层挤出技术制备了微层PVC片材,采用涂覆法制备了多层PVC/PVA复合片材,对其力学性能和阻隔性能进行了研究。结果表明:①多层结构有利于提高PVC/PVA复合片材的阻隔性能,涂覆PVA溶液增大了片材的拉伸强度。②微层PVC片材的分子链发生取向,沿挤出方向的拉伸强度明显高于垂直挤出方向;微层PVC片材的层数越多,取向作用越强,越有利于阻隔性能的提高。
Micro-layer PVC sheets were prepared by micro-layer extrusion technology, and PVC/ PVA composite sheets were prepared by coating method. Their mechanical properties and barrier proper- ties were studied. The results showed that: ① muhilayer structure was beneficial to improving the barrier properties of PVC/PVA composite sheet, and the tensile strength of the sheets increased due to coating PVA. ② The molecular chains of micro-layer PVC sheets were oriented, so the tensile strength along the extrusion direction was significantly higher than that along the direction perpendicular to extrusion direc- tion. The more layers of micro-layer PVC sheets had, the stronger the orientation effect was, the more beneficial to improving barrier properties was.