钛酸钡粒度分布及含量对聚偏氟乙烯基复合材料性能的影响

Effect of Size Distribution and Content of Barium Titanate on Properties of Polyvinylidene Fluoride Based Composites

采用溶液共混法制备了钛酸钡/聚偏氟乙烯(BT/PVDF)复合材料,研究了BT粒度分布及含量对复合材料介电性能、电气强度、储能性能和热稳定性的影响。结果表明:相较于单一粒径BT,双粒径BT共同填充的协同作用使复合材料具有更加优异的综合性能,且协同作用在两种粒径的BT等质量比时表现最为显著。随着填料含量的增加,复合材料的介电常数增大,热稳定性提升,介质损耗因数保持在相对较低的水平。当BT质量分数为60%,两种粒径BT的质量比为5∶5时,复合材料在100 Hz的介电常数达到46.5,是纯PVDF的5倍;其储能密度与极化强度分别为0.18 J/cm^(3)和0.0119 C/m^(2),相比纯PVDF分别提高了176%和310%。热失重5%的分解温度达到478.4℃,分别比S-BT和L-BT单独填充的PVDF基复合材料提高了1.3℃和30.3℃。

A barium titanate/polyvinylidene fluoride(BT/PVDF) composites was prepared by solution blending method, and the effect of size distribution and content of BT particles on the dielectric properties, electric strength,energy storage properties, and thermal stability of the composites were investigated. The results show that compared with single particle size BT, the synergistic effect of double particle size BT filler makes the composites have more excellent comprehensive properties, and the synergistic effect is the most remarkable when the mass ratio of BT with double size is equal to 1. With the increase of filler content, the dielectric constant and thermal stability of the composites increase, and the dielectric loss factor of the composites maintains at the relative low level. When the mass fraction of BT is 60%, and the mass ratio of BT with double size is 5∶5, the dielectric constant of BT/PVDF composites reaches 46.5 at 100 Hz, which is 5 times bigger than that of pure PVDF;the energy storage density and polarization are 0.18 J/cm^(3) and 0.011 9 C/m^(2), respectively, which are 176% and 310%higher than those of pure PVDF;the decomposition temperature corresponding to 5% of weight loss reaches478.4℃, which is 1.3℃ and 30.3℃ higher than that of PVDF composites filled with S-BT and L-BT, respectively.