同向非对称双螺杆混合石墨增强导热高分子材料性能研究

Properties of Thermally Conductive Polymers Reinforced with Graphite Mixed in a Co-rotating Non-symmetric Twin-screw

选用粒径为15μm的鳞片石墨和3μm的氧化铝（A1203）为导热填料，采用新型同向非对称双螺杆挤出机为加工设备，在石墨填充量为10％（质量分数，下同）而Al2O3填充量为10%～50％范围内，制备聚丙烯（PP）／Al2O3和PP／A1203／石墨导热高分子材料并进行性能测试。结果表明，添加少量石墨，在Al2O3填充量低时可增强导热高分子材料的拉伸强度，石墨与Al2O3的混杂减缓了拉伸强度下降的速率，改善了导热高分子材料的弯曲和冲击性能；PP／Al2O3／石墨的熔体流动速率比PP／Al2O3的小，PP／Al2O3／石墨比PP／Al2O3的负载热变形温度升高约15％。

Using flake graphite with particle size 15μm and alumina with particle size 3μm as thermally conductive filler, and novel co-rotating non-symmetric twin-screw extruder as processing machine, thermally conductive polymers of PP/Al2O3 and PP/Al2O3/graphite were prepared at the filling content of 10% graphite and 10%-50% alumina, respectively. It was found that the addition of a small amount of graphite may increase the tensile, bending, and impact strengths of PP/Al2O3 composites. Melt flow rate of PP/Al2O3/graphite was smaller than PP/Al2O3, and HDT of PP/Al2O3/graphite increased about 15% based on PP/Al2O3.