天然鳞片石墨/环氧树脂复合材料的制备及导热性能研究

以天然鳞片石墨为导热填料,E44型环氧树脂为基体,采用超声分散法制备天然鳞片石墨/环氧树脂复合导热材料.系统考察了天然鳞片石墨用量、石墨粒度和炭黑添加量等因素对复合材料导热性能的影响.结果表明:随着天然鳞片石墨用量增加,复合材料的导热系数增大,抗压强度先增加后减小；复合材料的导热系数随天然石墨粒径的增大而增大,抗压强度先减小后增加;在石墨/环氧树脂复合导热材料中添加不同用量的炭黑时,随着炭黑添加量的增加,复合材料的抗压强度增大,导热系数先增大后减小.制备天然鳞片石墨/环氧树脂复合导热材料的最佳配方为天然鳞片石墨用量45％,粒径≤270 μm,炭黑用量2％.

Preparation of natural graphite/epoxy resin composite and its thermal conductivity

The natural graphite/epoxy resin composites were prepared by ultrasonic dispersion method,using epoxy resin as the matrix,natural graphite as the filler,polyamide as curing agent and ethanol as the thinner.The influences of the natural graphite content,particle size and carbon black content on the properties of the composites were investigated.The results show that the thermal conductivity of the composite increases as the content of natural graphite increases,and the compression strength at first increases and then decreases sharply with increasing of the natural graphite content.Increasing particle size can improve the thermal conductivity,but the compression strength tends to decrease firstly and then increase.It is beneficial to improve the compression strength of composite by increasing the carbon black content,while the thermal conductivity of composite increases at the beginning and then decreases.The optimum graphite content,particle size and carbon black content are 45%,300 μm and 2%,respectively.