马来酸酐接枝PP/PE共混物及其木塑复合材料

Maleic Anhydride Grafted PP/PE Blend and Their Composites with Wood Fiber

通过聚丙烯(PP)与聚乙烯(PE)机械混合来模拟废旧塑料混合物,利用马来酸酐(MAH)对PP/PE混合物进行接枝改性,然后以接枝共混物作为基体与木纤维复合制备木塑复合材料。通过对比接枝前后的红外光谱图,证明MAH已成功接枝在PP/PE共混物上。力学测试结果显示:基体经过接枝改性后,复合材料的弯曲强度和无缺口冲击强度均大幅度升高,当MAH用量为1%时,弯曲强度提高了50.4%,无缺口冲击强度提高了90.8%,而以废旧塑料为原料制备的复合材料的弯曲强度和无缺口冲击强度分别提高40.2%和53.4%。微观相形态分析表明:通过接枝改性不仅改善了PP/PE共混体系的相容性,同时也显著改善了木纤维与PP/PE共混物之间的界面结合状况,因而宏观上表现为力学性能提高。这表明,共混接枝改性方法可能是利用混合废旧塑料制备高性能木塑复合材料的一条可行途径。

In this paper, the waste plastic mixture was simulated by mechanically mixing polypropylene （PP） and polyethylene （PE）, the PP/PE mixture was blended and at the same time grafted with maleic anhydride （MAH） by reactive extruding, and the wood plastic composites was prepared with the grafted blend, which was used as matrix, and wood fiber. By comparing the infrared spectrogram of the grafted PP/PE blend with that of the unmodified blend, it proved that MAH was grafted onto PP/PE blend. Mechanical testing results showed that the flexural strength and un-notched impact strength of the composites were both significantly enhanced by the blending-grafting modification of plastic mixture. When MAH dosage was 1% , the flexural strength increased 50.4% and the un-notched impact strength increased 90. 8%, and the flexural strength and the un-notched impact strength of the composite prepared from waste plastic increased 40.2% and 53.4% respectively. The micro-morphological analysis indicated that with modification the compatibility of PP and PE in the blend system was improved and the interfacial adhesion between wood fiber and PP/PE blend was also enhanced, thus it exhibited the elevation of the mechanical property. This blending-grafting modification method can be considered as a feasible approach to expand the use of mixing waste plastics in the manufacture of high performance wood plastic composites.