环氧树脂/聚氨酯/硅微粉复合材料的力学性能研究

Study on mechanical properties of epoxy resin/ polyurethane/silica micropowder composite material

为了满足路用涂层的力学性能需求,制备了以硅微粉为填料的环氧/聚氨酯热固性复合材料,研究了硅微粉加量对有机-无机界面相互作用力、拉伸性能的影响及相互关系。低温冷冻实验表明:EPU树脂具备聚氨酯的低温柔韧性,且硅微粉的加量不会影响EPU树脂的低温韧性。拉伸实验结果表明:当硅微粉的加量为EPU质量的4%时,硅微粉对EPU复合材料的增强和增韧效果最佳。通过DMA实验证实:在此加量下,EPU基体与无机SiO粒子界面之间有强相互作用力使玻璃化温度(T)升高。拉伸断裂面的SEM图显示,硅微粉的加入使EPU胶膜通过微空洞、裂纹铆钉以及塑性形变多种增韧机制阻止裂纹扩展,达到增强和增韧的效果。

In order to meet the requirement of mechanical properties in pavement coatings,the thermosetting composites are prepared by epoxy resin/polyurethane and silica micropowder as filler,and the effects of the silica micropowder dosage on the organic-inorganic interfacial force,tensile properties and their relationships are studied.The freezing test shows that EPU resin has the excellent flexibility at low temperature as same as polyurethane,and that the dosage of silica micropowder has no influence on it.The tensile results show that the silica micropowder has optimal reinforcing and toughness effects on EPU resin when its content is 4%mass of EPU.DMA results also confirm that the high interaction force at interface of EPU and SiOparticles under this concentration of silica micropowder causes increase in glass transition temperature(T).At the same time,the SEM images of tensile fracture surface indicate that the addition of silica micropowder in EPU can prevent crack propagation through several toughening mechanisms such as micro-cavity,crack rivet and plastic deformation,and further provide reinforcing and toughness effects.