杨木纤维尺寸对环氧树脂复合材料力学性能的影响

Effects of Poplar Wood Fiber(PWF)Size on Mechanical Properties of PWF/Epoxy Resin Composites

由木材剩余物杨木枝桠材为原料,制得杨木纤维的化学机械浆后,经直接烘干和溶剂置换两种不同的后续处理方法得到不同尺寸杨木纤维(PWF),再与环氧树脂E51经热压成型制备PWF增强环氧树脂(PWF/E51)复合材料。通过PWF微观形貌与尺寸分析,结合PWF/E51复合材料冲击断面微观形貌分析,探讨了PWF尺寸对PWF/E51复合材料力学性能的影响。研究结果表明:PWF尺寸对增强环氧树脂复合材料力学性能有较大影响,随PWF长径比增大,复合材料的冲击强度和弯曲强度均先增大后减小,其中溶剂置换处理的PWF/E51复合材料(长径比值14.8)力学强度最佳,冲击强度7.1 kJ/m2,弯曲强度68.2 MPa。此外,经溶剂置换处理的PWF/E51复合材料的力学强度较直接烘干处理有所提高。

Poplar wood fiber(PWF)with different sizes was prepared from poplar residues of chemi-mechanical pulping and subsequent treatments(directly drying and solvent replacement).The PWF/epoxy resin(PWF/E51)composites were prepared by hot pressing molding method.The effects of fiber size on the mechanical properties of composites were investigated by the analysis of micro-morphology and size of the PWF as well as the micro-morphology of the impact fracture surface of the composites.The results showed that the fiber size had a significant effect on the mechanical properties of composites.With the increase of the ratio of length to diameter of PWF,the impact and flexural strength of PWF/epoxy resin composites were increased first and then decreased.Among them,the PWF with the ratio of length to diameter 14.8,which were prepared from the solvent replacement,showed the best reinforcement of the mechanical strength of the epoxy resin composites.And the impact strength and flexural strength were 7.1 kJ/m2 and 68.2 MPa,respectively.In addition,the mechanical strength of composites reinforced with the solvent replacement PWF was higher than that reinforced with the directly dried PWF.