中文摘要：

利用短纤维代替粉状材料作为增强材料制备纤维增强型聚丙烯基复合材料,研究不同的木纤维/聚丙烯配比、密度以及不同浓度的碱处理对木纤维/聚丙烯复合材料物理力学性能的影响。结果表明,目标密度仅为0.55g/cm3时,且当木纤维与聚丙烯的配比为30︰70时,木纤维/聚丙烯复合材料表现出最佳的物理力学性能,但仍达不到标准要求。因此,综合产品成本和物理力学性能,选取了50︰50的原料配比,研究密度对该产品物理力学性能的影响。进一步研究表明,随着密度的增加,复合材料的力学强度得到不断提高,当密度为0.70g/cm3时,板材的力学性能就可以满足国标要求但吸水厚度膨胀率不能满足国标要求。当密度为0.83 g/cm3时,板材的力学性能满足国标要求,吸水厚度膨胀率有减小的趋势。为了进一步提高该复合材料的物理力学性能,利用浓度分别为1%,3%和5%的氢氧化钠溶液对木材纤维和工业大麻杆纤维进行处理,结果表明,经过碱处理后复合材料的吸水厚度膨胀率减小了,静曲强度和弹性模量仍可满足标准要求。

英文摘要：

The composites were manufactured with polypropylene（ PP） and natural-wooden-fiber instead of the natural-wooden-powder and PP to gain the composites of better physical and mechanical properties. It researched the influences of different ratios of natural-wooden-fiber to PP,different densities of composites and different concentrations of alkali solutions on the physical and mechanical properties of natural-wood-fiber / PP composites. The results showed that,as the ratio of natural-wooden-fiber to PP was 30 percent to 70 percent,the mechanical and physical properties of composites were best while those could not reach the requirement of the standard for woodplastic composites（ WPC） for the target density only was 0. 55 g / cm3. Considering the cost of the composites,the50 ︰ 50 natural-wooden-fiber to PP was selected to research the influence of density on the properties of composites. As the density of composites increasing,the mechanical properties of composites was increasing either; when the target density was 0. 70 g / cm3,the mechanical properties of the composites could reach the requirements of the standard and when the target density was 0. 83 g / cm3,the mechanical properties and physical properties of the composites both could be improved. To promote the mechanical and physical properties of the composites,the studied influence of the alkali solutions on the properties（ including the mechanical and physical properties） of the composites and the alkali solutions concentration were 1 percent,3 percent and 5 percent respectively,and the results showed that the physical properties of the composites were improved after the fiber were treated by the alkali solution,and the mechanical properties could satisfy the requirement of the standard.