电场作用下磺化聚苯乙烯微球在弹性体中梯度结构构建及性能研究

先采用硫酸对聚苯乙烯微球经过磺化得到带正电荷的磺化聚苯乙烯(s PS),将s PS分散在聚二甲基硅氧烷(PDMS)预聚体中,在高压直流电场下通过电泳作用形成梯度结构,再通过PDMS的热固化后将梯度结构固定下来。采用马尔文Zeta电位仪分析了s PS微球电荷,扫描电镜(SEM)对s PS以及s PS/PDMS梯度膜的结构进行表征,动态热机械分析仪测试了材料的动态力学行为和介电损耗。结果表明,电压强度为500 V/mm时,s PS能够在PDMS预聚体中通过电泳作用形成梯度结构,s PS总质量分数为20%时,s PS/PDMS梯度膜相比相同组成的均匀膜断裂伸长率提高了9. 41%,损耗因子在所测得温度范围(-70~200℃)均提高。在s PS的玻璃化转变温度附近,s PS/PDM S梯度膜比均匀膜损耗因子提高了30%。进一步对梯度结构膜力学行为及介电损耗增强效应进行了详细分析。

Gradient Structure Construction and Properties of Sulfonated Polystyrene Microspheres in Elastomers under Electric Field

Positive charged polystyrene microspheres(sPS) were synthesized by sulfonation of polystyrene(PS) particles with sulfuric acid.Then the sPS was dispersed in a prepolymer of poly dim ethylsiloxane(PDMS).The sPS formed a gradient structure by electrophoresis effect in direct current electric field.The gradient morphology was frozen by thermal curing of PDMS.sPS microsphere charge was analyzed by Marvin Zeta potentiometer.The structure of sPS and sPS/PDMS gradient membranes were characterized by scanning electron microscope(SEM).The dynamic mechanical behavior and dielectric loss of the material were measured by dynamic mechanical analyzer.The results show when the voltage strength is 500 V/mm,sPS could form gradient structure in PDMS prepolymer by electrophoresis.When the content of sPS is 20%,the elongation at break of sPS/PDMS gradient membrane is 10%higher than the homogeneous membranes of the same composition.The loss factor could be improved in the temperature range of-70~200℃.The loss factor of sPS/PDMS gradient film increases 30% comparing with uniform film near the glass transition temperature of the sPS.The mechanical behavior of gradient structure membrane and dielectric loss enhancement effect were further analyzed.