Preparation And Properties Of Polystyrene / Graphite Conductive Composite Material

Composites based on expanded graphite (EG), polystyrene (PS) and plasticizer were prepared. The effect of expanded graphite amount, plasticizer amount and the pretreatment of expanded graphite on electric conductivity, mechanical property and rheology property were researched. The dispersity of expanded graphite particles in the composite was researched by means of SEM.The electrical resistivity decreases with the increase of the graphite amount. The threshold value was only 5%, and the lowest electrical resistivity is 8.91×10~5(Ω·cm). The tensile strength decreases at first and then increases with the increase of the expanded graphite amount, and the trends of impact strength is reverse. Besides, the viscosity increases as increasing the amount of expanded graph(?)e. The electrical resistivity, the tensile strength and the viscosity all decreases while the impact strength increases as increasing the amount of plasticizer. Among various approaches of the surface pretreatment of expanded graphite, the method of using surface active agent is the most efficient, and the electric conductivity of prepared composites can reach 2.29×10~5Ω·cm. The mechanical properties like tensile strength and impact strength are improved by surface pretreatment for the expanded graphite. Thereinto, vie the surface pretreatment with coupling agent, tensile strength and impact strength of prepared composites are the highest, which reach 11.513 MPa and 78.593 KJ/m~2 separately. With the surface pretreatment for the expanded graphite, the viscosity of composites is declined. The degree of viscosity declination of the sample prepared with surface active agent used as surface modification agent is the greatest.