微纳层叠技术对线性低密度聚乙烯材料性能的影响

Properties of LLDPE via the Micro-nano Laminating Technology

采用实验室自主设计的微纳层叠挤出成型设备,制备了1层、9层和81层的线性低密度聚乙烯(LLDPE)实验样品,并对不同层数的样品进行取向度、结晶度以及拉伸强度测试,主要研究了微纳层叠技术对聚合物分子链取向、结晶度以及拉伸强度的影响。实验结果表明:通过微纳层叠技术,提高了LLDPE的结晶度,9层、81层LLDPE的结晶度较1层LLDPE结晶度的38.56%分别提高到50.62%和54.42%;同时还提高了LLDPE沿挤出方向(MD)和垂直于挤出方向(TD)的取向度和拉伸强度,具有双向拉伸作用,且扭转层叠单元的使用个数越多,双向拉伸效果越明显。

Alternating layers of samples were prepared by self-made micro-nano extrusion device based on pure linear low density polyethylene（ LLDPE）. And the effect of micro-nano laminating technology on the degree of orientation, crystallization and tensile strength were characterized by ultrasonic, tensile and DSC tests. The results showed that the degree of orientation were increasing at both the machine direction and perpendicular to the machine direction as the layers increasing, which made the erystallinity and the tensile strength improved. The micro-nano laminating technology had the function of biaxial orientation, and the more layer laminating devices were used, the more obviously effect of biaxial orientation would be.