改性氮化铝／三元乙丙橡胶复合材料导热性能和力学性能的研究

选用三元乙丙橡胶（EPDM）为基胶，氮化铝（A1N）为导热填料，通过酚醛树脂（PF）对氮化铝进行表面改性处理，增加其在橡胶基体中的分散性。利用接触角和TGA测试表征改性效果。将改性前后的氮化铝分别填充到三元乙丙橡胶中，研究酚醛树脂改性氮化铝对复合材料的导热性能及力学性能的影响规律。结果表明：改性后氮化铝表面自由能均减小，氮化铝表面包覆了有机基团，减弱了其在橡胶基体中的团聚作用。热分解曲线可以说明，3种改性配比（1#～3#，m（PF）：m（A1N）=1：5，1：4，1：3）氮化铝的酚醛树脂包覆量为1#〈2#〈3#，填充改性后氮化铝的复合材料导热性能均有不同程度的提高，而力学性能均有所降低。综合考虑，酚醛树脂改性氮化铝的最佳质量配比为m（PF）：m（A1N）=1：4。

Thermal Conductivity and Mechanical Properties of EPDM Rubber Filled with Modified-AIN

AIN were used as thermal conductive fillers of EPDM rubber. And in order to increase the dispersion of AIN in the matrix, the surface treatment of AIN were coated by phenol formaldehyde resin （PF）. The contact angle and TGA of AIN and modified AIN were studied. The thermal conductivities and mechanical properties of composites material were also investigated. The results show that the surface free energy of modified AIN is lower than unmodified, the surface of modified AIN are coated by organic groups, so the modified AIN are easier dispersion in the matrix. Through the TGA analysis, it can be indicated that the surface coating thickness is 1 #〈2 #〈3#. With the increase of the filler, the thermal conductivities of composites are all on the rise, while the mechanical properties decreased in different degree. Synthetic analysis indicates that, the optimal ratio of AIN and PF is m（PF） ： m（AIN）=1：4.