煤粉复合聚烯烃导热材料的制备及表征

Preparation and Characterization of Coal/Polyolefin Composite with Thermal Conductivity

采用γ-(2,3-环氧丙氧)丙基三甲氧基硅烷处理的碳纤维(CF)和煤粉(Coal)作为导热填料,用熔融共混的方法制备Coal/聚烯烃导热复合材料,分析了CF含量对复合材料力学性能、导热性能、热稳定性和微观形貌的影响。结果表明,当CF的含量为15%时,复合材料的拉伸强度、弯曲强度和热导率均达到最大,与填充前相比,分别提高了27.6%、17.8%和61.2%;热导率的实验结果与Maxwell-Eucken模型预测结果相匹配;随着升温速率的提高,热重曲线和微商热重曲线向高温区移动,降解峰变宽,聚合物最大失重率温度升高;复合材料的结晶峰为单峰,低含量的CF有利于减少异相成核、晶核长大及缩短半结晶时间;当CF含量在5%和7.5%时,CF被PP基体包覆,且粘结牢固,分散均匀,取向明显。

Thermal conductive coal/polyolefin composite was prepared by melt blending method withγ-(2,3-epoxypropoxy)propyltrimethoxysilane treated carbon fiber(CF)and coal as thermal conductive filler.The effects of CF content on mechanical properties,thermal conductivity,thermal stability,and the composite's microstructure were analyzed.The results showed that the tensile strength,bending strength,and thermal conductivity of the composite increases by 27.6%,17.8%,and 61.2%higher than before filling.Moreover,the experimental results of thermal conductivity were matched with those predicted by the Maxwell-Eucken model.With the increase of the heating rate,TG and DTG curved shift to the high-temperature region,the degradation peak widened,and the maximum weight loss rate temperature increased;The crystallization peak of composite was a single peak,and low CF content was helpful to heterogeneous nucleation,crystal growth and semi-crystallization time shortening;when the CF content was 5%and 7.5%,CF was coated by PP matrix,which had firm adhesion,even dispersion,and obvious orientation.