聚苯乙烯/膨胀石墨导电复合材料性能研究

Study on properties of polystyrene/expanded graphite conductive composites

以聚苯乙烯为基体,膨胀石墨为填料,邻苯二甲酸二辛酯为增塑剂,通过熔融共混法制备复合材料。并研究了复合材料的导电性能、力学性能和熔体流变性能与膨胀石墨含量的关系。主要结论如下:随着膨胀石墨含量的增加,复合材料的体积电阻率逐渐减小,渗流阈为5%,复合材料的体积电阻率最小为8.65×10~5(Ω·cm),膨胀石墨的含量为13%。当膨胀石墨含量在5%~10%之间时,复合材料的导电性迅速变化。而复合材料的拉伸强度则随之先减小后增大,当膨胀石墨含量为5%时,拉伸强度最小为4.52 MPa。冲击强度小增大后减小,当膨胀石墨含量为5%时,冲击强度最大,为7.5 kJ/m^2。

In this paper, polystyrene was used as matrix, expanded graphite as filler and dioctyl phthalate as plasticizer, composites were prepared by melt blending method. The relationship between the electrical conductivity, mechanical properties, melt rheological properties and the content of expanded graphite of the composites were studied. The main conclusions are as follows： with the increase of the content of expanded graphite, the volume resistivity of the composite decreases gradually, the percolation threshold is 5%, and the minimum volume resistivity of the composite is 8.65×105 （Ω·cm）. The content of expanded graphite is 13%. When the content of expanded graphite is between 5% and 10%, the conductivity of the composite material changes rapidly. The tensile strength of the composites decreases first and then increases. The tensile strength is the lowest when the content of expanded graphite is 5%, which is 4.52 MPa. The impact strength increases first and then decreases. The impact strength is maximal at 7.5 kJ/m^2 when the content of expanded graphite is 5%.