铝矾土改性竹粉/HDPE复合材料性能

Properties of bamboo flour/HDPE composites modified by bauxite

为制备高性能的木塑复合材料,扩展其应用领域,采用A-171硅烷偶联剂对竹粉进行表面改性,并添加一定量的铝矾土,经热压成型制备了竹粉/高密度聚乙烯(HDPE)复合材料。分析了铝矾土用量对竹粉/HDPE复合材料力学性能、耐热性和摩擦性能的影响。采用XRD分析了铝矾土的结晶特性,利用SEM和EDS分析了竹粉/HDPE复合材料的断面形貌和表面元素分布情况。结果表明:加入适量铝矾土后,竹粉/HDPE复合材料的力学强度、耐热性及耐磨性能得以改善。铝矾土在竹粉/HDPE复合材料基体中分布均匀,可有效承担载荷,同时提高了竹粉/HDPE复合材料的结晶性能,降低了竹粉/HDPE复合材料在外在应力下引起的变形和破坏;但铝矾土用量过高,分布不均匀,容易形成团聚现象,导致竹粉/HDPE复合材料的力学强度和耐磨性降低,线性热膨胀系数增大。

For preparing high-performance wood plastic composites and broading the application fields, the surface of bamboo flour was modified by A-171 silane coupling agent and an amount of bauxite was added into it. The bamboo flour/high density polyethylene （HDPE） composites were prepared by hot pressing technology. The influence of bauxite content on mechanical properties, heat resistance and tribologieal behavior of the bamboo flour/HDPE com- posites were investigated. The crystallization characteristics of bauxite were observed using XRD and their morphol- ogy of fracture surface and distribution of elements on the surface were analyzed by SEM and EDS. The results show that the mechanical strength, heat resistance and the wear resistance of bamboo flour/HDPE composites are improved by adding the appropriate content of bauxite. Bauxite can be evenly distributed in bamboo flour/HDPE composite matrix and bear the load effectively, and the crystallization properties of bamboo flour/HDPE composites are improved. The deformation and {ailure of bamboo flour/HDPE composites under exterior stress were reduced. However, when the content of bauxite is too high, the mechanical strength and the wear resistance decrease, and the coefficient of linear thermal expansion of bamboo flour/HDPE composites increases, because that the bauxite is unevenly distributed and formes agglomeration easily.