竹粉粒径对竹/聚丙烯复合材料力学性能的影响

Effect of Particle Size of Bamboo Flour on Mechanical Properties of Bamboo/Polypropylene Composites

以竹粉和聚丙烯粉料为原料,马来酸酐接枝聚丙烯为偶联剂,通过注塑成型制备了竹塑复合材料。研究了不同粒径竹粉对复合材料力学性能的影响。结果表明:不同粒径的竹粉对复合材料拉伸性能、弯曲性能及冲击强度均有显著的影响。竹粉粒径在40～120目时,随着粒径的减小,复合材料的拉伸强度、弯曲强度,以及缺口冲击强度呈逐渐减小的趋势。当粒径达到200目时,复合材料的拉伸强度、弯曲强度及缺口冲击强度却有所增大。竹粉粒径为20目时,复合材料的拉伸强度、弯曲强度以及缺口冲击强度均比40目的要低。大粒径竹粉(40目)与小粒径竹粉(200目)填充的复合材料表现出的不同力学性能,可能与竹粉与基体塑料界面结合、纤维形态、表面粗糙度以及内部空隙状况不同有关。

An experiment was conducted to prepare bamboo/polypropylene composites by mixing bamboo flour with polypropylene flour by Brabender Intelli-Torque Plasti-Corder first, then molding by injection machine, using maleic anhydride grafted polypropylene as coupling agent. Effects of different particle sizes of bamboo flour on mechanical properties of the composites were studied. Results showed that different particle sizes of bamboo flour had obvious effect on the tensile strength, flexural strength and impact strength of the samples. As the bamboo particle sizes were between 40 and 120 meshes, the tensile strength, flexural strength and impact strength of the samples exhibited a decreasing tendency with particle size increasing. However, the tensile strength, flexural strength and impact strength showed an increasing tendency as the particle size was 200 meshes. And the tensile strength, flexural strength and impact strength of bamboo fiber-reinforced polypropylene composites with particle size of 20 meshes were better than that of 40 meshes. The mechanical performances of bamboo/polypropylene composites with particle size of 20 meshes were different from those of 200 meshes, which might be related to interface bonding between bamboo particle and plastic matrix, the morphology and surface coarseness of fibers and void ratio of composites.