Preparation And Property Of Crosslinked Polystyrene Composites Modified By T-ZnOw And MOSw

Crosslinked polystyrene(CLPS)is a kind of outstanding dielectric materials with excellent properties like low dielectric loss,low dielectric constant,high dimensional stability,high radiation resistance,high modulus and voltage insulation resistance.It has been widely used in microwave circuits,microwave communications,radar antennas and other fields,especially as a kind of insulating material used in pulse power systems.But with the development of large-scale pulse power device,the mechanical properties and electric properties of CLPS have been unable to meet the application requirements.Therefore,in order to meet the development of pulse power technology,it is necessary to improve the comprehensive performance of cross-linked polystyrene.Based on the above development backgrounds,we used Tetra-needle like ZnO whiskers(T-ZnOw)and Magnesium oxysulfate whiskers(MOSw)as additives and prepared a series of T-ZnOw/CLPS composites and MOSw/CLPS composites by using a combination of methods including bulk polymerization and ultrasonic dispersion,controlling the amount and dispersion of T-ZnOw and MOSw in styrene.The CLPS and CLPS composites were characterized using scanning electron microscopes(SEM),vacuum surface flashover instrument,high resistance meter,thermal gravimetric analysis(TGA)and other testing methods.The results of the study show:(1)The structure and properties of CLPS composites are related to the content of inorganic fillers.The results of mechanical properties test show that the elongation at break and tensile strength of T-ZnOw/CLPS composites decrease with the increase of whisker content,and the impact strength increases first and then decreases with the increase of whisker content.When the content of T-ZnOw is 3wt%,it reaches the maximum value of 6.87kJ/m.The modulus of elasticity and energy storage modulus of the composite display a first rise and then decrease with the increase of the addition of whiskers,and the modulus of elasticity reaches the maximum value at 4065.8Mpa when the content of whiskers is 4wt%.The thermal stability,surface flashover and surface conductivity of T-ZnOw/CLPS composites were improved compared with initial CLPS.(2)The tensile strength of MOSw/CLPS composites has not been improved.The elongation at break of composites decreases with the increase of MOSw content.The impact strength of the composite increases first and then decreases with the increase of MOSw content.When the content of MOSw is 3wt%,it reaches the maximum value at 12.82KJ/m2,and the tensile modulus and modulus of elasticity of the composites increase first and then decrease with the increase of the content of MOSw.The thermal stability of MOSw/CLPS composites is improved by incorporation of MOSw.The surface flashover performance of composites increases first and then decreases with the increase of MOSw addition.When the whisker's addition is wt4%,the Vho of sample reaches about 160kV.The surface resistivity constant of composites is not significantly related to the addition amount of MOSw.