Al_2O_3的表面改性及其在环氧树脂导热涂料中的应用

Surface modification of Al_2O_3 and its application in thermal conductive coating based on epoxy resin

先用硅烷偶联剂KH-560对Al_2O_3粉末填料进行表面改性,再按一定比例将其添加到E-20型环氧树脂溶液中,并配合自制的潜伏型环氧树脂固化剂及其它助剂,制备了环氧树脂导热涂料,用拉伸试验、附着力测试、导热率测试和热失重分析对导热涂层进行了研究。结果表明,随着填料含量的增加,涂层的导热率开始以缓慢的速度增长,当填充量超过45%时,导热率快速增大;少量的填料能提高涂层的拉伸强度,而填充量过高时,拉伸强度反而被削弱;将表面改性后的Al_2O_3用于导热涂层能得到比改性前更大的拉伸强度和更高的导热率;当改性Al_2O_3的添加量为75%时,涂层的导热率达到1.33 W/(m·K),涂层对铝材的附着力级别为0,对应的拉伸强度和断裂伸长率分别为15.4 MPa和8.4%。

Al2O3 particle as thermal conductive filler was treated by silane coupling agent（KH-560）,which was then blended with E-20 epoxy resin solution,homemade latent curing agent and some other kinds of additives to make thermal conductive coating.Tensile strength,adhesion force,thermal conductivity and TG were tested to study the properties of coating.The results indicatethat the thermal conductivity increases slowly with the adding of filler in the beginning,when the content of filler reaches 45%,the increasing rate magnifies rapidly.A small quantity of filler helps to enhance the tensile strength of coating,which recedes when the filler content is excessively high.The coating with modified Al2O3 owns better thermal conductivity and mechanical properties than that with unmodified Al2O3.When the content of modified Al2O3 is 75%,the thermal conductivity of coating is 1.33 W/（m·K）,the adhesion force of coating on aluminum is level 0,and the corresponding tensile strength and elongation at break is 15.4 MPa and 8.4%,respectively.