液晶改性芳纶增强环氧树脂的相容性与力学性能

摘要

针对环氧树脂复合材料存在的应力开裂以及与基体界面相容性差等问题,采用液晶和离子单体对芳纶纤维进行改性,再与环氧树脂及固化剂按一定比例混合,制得液晶改性芳纶增强环氧树脂复合材料.正交试验结果表明,常温下固化20 min,芳纶、环氧树脂与固化剂的质量比为0.07∶35∶11,复合材料的弯曲应力为445.6 MPa,应变为0.975%,比水解芳纶增强环氧树脂复合材料、芳纶增强环氧树脂复合材料的弯曲应力分别提高了29%和33%.扫描电镜研究表明,复合材料中分散相在基体中的分散性较好,有良好的界面相容性,断面处的断裂方式由脆性断裂变为韧性断裂.红外光谱研究表明,加入液晶改性芳纶的复合材料出现了磺酸基团和氮氮双键的特征吸收峰.%To solve such problems as stress crack and poor interface compatibility in epoxy resin composites,a liquid crystalline modified aramid reinforced epoxy resin composite was prepared through modifying aramid fiber by liquid crystalline and ion monomer and then mixing with epoxy resin and curing agent in certain proportion.The results of orthogonal experiment reveal that when the mass ratio of aramid fiber,epoxy resin and curing agent is 0.07∶ 35∶ 11 as well as the curing time at room temperature is 20 minutes,the bending stress and strain of the fabricated composite are 445.6 MPa and 0.975%,respectively.The bending stress of liquid crystalline modified aramid reinforced epoxy resin composite increases by 29% and 33% than that of hydrolytic aramid reinforced epoxy resin composite and raw aramid reinforced epoxy resin composite,respectively.The scanning electron microscope observation shows that the modified aramid has good dispersion and interface compatibility in epoxy resin matrix.The fracture mode for the composite changes from brittle fracture to ductile fracture.The infrared spectroscopy（IR） investigation indicates that the S=O and N=N characteristic absorption peaks appear for the composite with adding the liquid crystalline modified aramid.