丙烯-乙烯共聚物/乙烯-1-辛烯共聚物层状复合材料的力学性能研究

利用自主设计的一套可进行微层共挤出的口模,分别制备了2层、16层、32层和64层丙烯-乙烯共聚物(PPE)/乙烯-1-辛烯共聚物(POE)交替层状复合材料。研究了制得的层状复合材料的应力-应变行为,利用等效盒子模型(equivalent box model)描述了层状复合材料与相应的常规PPE/POE共混材料力学行为的区别.通过对共挤出材料和共混材料的拉伸数据进行分析后发现,具有层状结构特别是多层结构的共挤出材料具有比共混材料更为优异的屈服和断裂伸长性能.

STUDY ON THE MECHANICAL PROPERTIES OF PROPYLENE-ETHYLENE COPOLYMER/ETHYLENE-1-OCTENE COPOLYMER STRATIFIED COMPOSITES

A set of microlayer coextrusion system was designed to prepare 2-layer,16-layer,32-layer and 64-layer composites.The blended materials were also prepared by conventional blending technology to study the effects of phase morphologies on properties of blends.The SEM micrographs showed that the multiplying elements acted as the function of delamination and multiplication.For investigating the mechanical properties of stratified and blended samples,an equivalent box model was introduced,and a series of corresponding tensile tests were performed.Both the theoretical and experimental results showed that with the same volume fraction of POE(V_(POE)),the stratified composites,especially multilayer samples,had higher yield strength and a comparable elongation at break comparing with those of the blends.According to stress-strain curves,it was illustrated that the yield phenomena behaved more evidently for 64-layer samples than for blends,which almost had no yield peak,when V_(POE) approached to 50%.By studying the effect of layer numbers on tensile properties,it was found that when V_(POE) was not too great,the yield strength was even larger than theoretical values acquired by an additive principle.Those distinct characteristics of multilayer materials in the aspect of mechanical properties might provide a novel approach to produce high-performance composites.