助剂对木粉/高密度聚乙烯复合材料成型特性的影响

Effects of processing agents on the processing properties of wood powder/HDPE composites

以双螺杆流变仪制备了木粉/高密度聚乙烯(HDPE)复合材料试样,考察了7种不同加工助剂对木粉/HDPE复合体系成型性能和力学性能的影响。结果表明,不同助剂对木粉分散性和加工能耗影响不同。增塑剂硬脂酸(HSt)可明显提高木粉分散性,乙撑双硬脂酸酰胺(EBS)、硬脂酸锌(ZnSt)和硬脂酸钙(CaSt)等降低木粉分散性。同时,添加增塑剂可有效降低能耗,起到增塑降黏作用。加入马来酸酐接枝聚乙烯(PE-g-MAH)可增强界面结合力,提高木粉分散性,但同时导致加工黏度增大,加工能耗提高。和纯HDPE试样相比,添加了PE-g-MAH的木粉/HDPE复合材料弯曲强度提高31.6%,拉伸强度提高87.2%,而EBS、ZnSt、CaSt、HSt和聚乙烯蜡等润滑剂会导致力学性能有不同程度的降低。研究结果对木塑复合材料加工工艺和配方优化具有实际指导意义。

Wood powder/high density polyethylene（HDPE）composites were fabricated by twin screw extruder,and the effects of seven processing agents on the processing and mechanical properties of the wood powder/high density polyethylene were analyzed.Results showed that the dispersity of wood powder is dependent on the type of processing agent.The addition of octadecanoic acid（HSt）could improve the dispersity significantly.However,ethylene bis stearamide（EBS）,zinc stearate（ZnSt）and calcium stearate（CaSt）are not helpful for improving the dispersity of wood powder.Meanwhile,adding of plasticizer could reduce energy consumption during the processing of the composites.The flexural and tensile strength of the wood powder/HDPE composites with PE-g-MAH was 31.6% and 87.2%,respectively,higher than those of HDPE without wood powder.In contrast,adding EBS、ZnSt、CaSt、HSt and low molecular PE in wood powder/HDPE could reduce the mechanical property of the composites.The results are useful for the optimization of the processing technology and formula of wood plastic composites.