高密度聚乙烯／植物纤维复合材料性能研究

摘要

采用双螺杆挤出机制备了一系列的高密度聚乙烯(PE–HD)／木粉(WF)和PE–HD／秸秆粉(SF)复合材料，研究了马来酸酐接枝聚乙烯(PE-g-MAH)及丙烯酸酯接枝聚乙烯(PE-g-AE)的用量对复合材料的拉伸性能、冲击性能和熔体流动速率(MFR)的影响，并对PE–HD／WF与PE–HD／SF复合材料的性能进行了比较。结果表明，PE-g-MAH和PE-g-AE均可增韧PE–HD／WF和PE–HD／SF复合材料，PE-g-AE的增韧效果总体上优于PE-g-MAH；PE-g-MAH和PE-g-AE降低了PE–HD／WF复合材料的拉伸强度，但对PE–HD／SF复合材料有一定的增强作用；PE-g-MAH和PE-g-AE可在一定程度上提高PE–HD／WF复合材料的MFR，而PE–HD／SF复合材料的MFR总体上随PE-g-AE用量增加而增大，随PE-g-MAH用量增加而减小；在PE-g-AE作用下，除拉伸强度外，PE–HD／SF复合材料的冲击强度、断裂伸长率、MFR总体上均高于PE–HD／WF复合材料；当PE-g-AE的用量为其与PE–HD总质量的5%时，PE–HD／SF复合材料的综合性能最佳。%A series of high density polyethylene (PE–HD)/wood flour (WF) and PE–HD/straw flour (SF) composites were prepared in two-screw extruder. The effects of contents of maleic anhydride grafted polyethylene (PE-g-MAH) and acrylic ester grafted polyethylene (PE-g-AE) on tensile properties,impact properties and melt flow rate (MFR) of the composites were investigated and the properties of the two composites were compared. The results show that both PE-g-MAH and PE-g-AE can toughen the PE–HD/WF and PE–HD/SF composites,and overall,the toughening effect of PE-g-AE is superior to that of PE-g-MAH. PE-g-MAH or PE-g-AE decreases the tensile strength of the PE–HD/WF composite but increases the tensile strength of the PE–HD/SF composite to some extent. MFR of the PE–HD/WF composites can be improved by PE-g-MAH or PE-g-AE in some degree,but MFR of the PE–HD/SF composite increases generally with the increase of PE-g-AE content and decreases with the increase of PE-g-MAH content. Except tensile strength,the impact strength,elongation at break and MFR of the PE–HD/SF composite are higher than those of the PE–HD/WF composite in general with the addition of PE-g-AE. When the PE-g-AE content is 5%of total mass of PE-g-AE and PE–HD,the comprehensive mechanical properties of the PE–HD/SF composite is best.