玻璃纤维含量对竹粉/高密度聚乙烯复合材料性能的影响

Effects of glass fiber content on properties of bamboo flour/high density polyethylene composites

为利用玻璃纤维提高木塑复合材料的综合性能,探讨玻璃纤维含量对竹粉/高密度聚乙烯（HDPE）复合材料性能的影响规律,首先,采用A-171硅烷偶联剂对竹粉表面进行了改性,并加入了一定量的玻璃纤维;然后,采用热压成型工艺制备了玻璃纤维-竹粉/HDPE复合材料;最后,考察了玻璃纤维含量对复合材料力学性能、热学性能及摩擦学性能的影响,并利用SEM观察材料的断面和磨损表面形貌。结果表明：当玻璃纤维含量为3wt%时,能显著提高竹粉/HDPE复合材料的拉伸强度和弯曲强度,与未添加玻璃纤维的复合材料相比,添加玻璃纤维后复合材料的拉伸强度和弯曲强度分别提高了19.41%和23.54%;在30~60℃温度范围内,复合材料长度-宽度方向上的线膨胀系数随着玻璃纤维含量的增加而明显减小,而同一复合材料的线膨胀系数随温度的升高而逐步增大;在氮气气氛下,随玻璃纤维含量的增加,竹粉/HDPE复合材料的摩擦系数先逐渐增大,而后基本保持不变,磨损率逐渐减小。所得结论显示玻璃纤维含量为3wt%~7wt%的木塑产品适用于建筑横梁（如凉亭或桥梁等）,而玻璃纤维含量为7wt%~10wt%的木塑产品适用于高人流量场所（如公园或休闲绿道等）的地面铺装。

In order to enhance the comprehensive properties of wood plastic composites by using glass fiber and investigate the effect laws of glass fiber content on the properties of bamboo flour/high density polyethylene（HDPE）composites,the surfaces of bamboo flour were modified by A-171 silane coupling agent and a certain amount of glass fiber were added firstly.Then,glass fiber-bamboo flour/HDPE composites were prepared by hot pressing molding technology.Finally,the influences of glass fiber content on the mechanical properties,thermal properties and tribological behaviors of the composites were observed,and the morphologies of fracture surfaces and worn surfaces of the materials were observed by SEM.The results show that when the glass fiber content is 3wt%,the tensile strength and flexural strength of bamboo flour/HDPE composites can be enhanced significantly;comparing with the composite without the addition of glass fiber,the tensile strength and flexural strength of composites after the addition of glass fiber increase by 19.41%and 23.54%respectively.The coefficient of linear expansion of composites in length-width direction decreases obviously with the glass fiber content increasing during the temperature range of 30-60 ℃,while the coefficient of linear expansion of the same composite gradually increases with the temperature increasing.In nitrogen atmosphere,with the glass fiber content increasing,the friction coefficient of bamboo flour/HDPE composites increases gradually at first and then almost remains unchanged,and the wear rate decreases gradually.The conclusions obtained show that the wood plastic composite products with the glass fiber content of3wt%-7wt%are suitable for construction beams（such as pavilions or bridges et al）,while the wood plastic composite products with the glass fiber content of 7wt%-10wt% are suitable for the ground pavement for places with large flow of people（such as park or recreational greenway et al）.