机载龙伯透镜天线用聚苯乙烯泡沫塑料的制备及介电常数调控

针对雷达通讯微波频段新型轻质介电复合材料的迫切需求,开展高介电性能复合材料的研究具有现实意义。采用悬浮聚合法制备不同密度的聚苯乙烯泡沫,研究了聚苯乙烯泡沫的介电常数与密度之间的关系,分析了钛酸钡粉末的介电性能。采用干混法添加钛酸钡粉末制备介电常数可调控的轻质钛酸钡/聚苯乙烯复合泡沫。聚苯乙烯泡沫的介电常数随密度增大,表现出弱的频率依赖性和低介电损耗。钛酸钡粉末具有高的介电常数和较低的介电损耗。BaTiO_3/PS复合材料的介电常数随着BaTiO_3含量的增加而升高。相同介电常数的BaTiO_3/PS复合材料和聚苯乙烯泡沫相比,密度显著下降,说明添加BaTiO_3可以实现介电材料的轻质化。

Preparation and Dielectric Properties of Polystyrene Foam Material Used for Luneburg Lens Antenna

The research on the composite material with high dielectric property is significant for the need of a new type of light dielectric composite material in modern radar and communication system. Polystyrene (PS) foam with different densities was synthesized by suspension polymerization, and the relationship between the dielectric constant and the density of PS foam was studied. The dielectric property of barium titanate (BaTiO₃) powder were analyzed. The light barium titanate/polystyrene composite foam was prepared by the dry-mixing method. The dielectric constant of foam or BaTiO₃/PS composites increases with the density and shows weak frequency-dependence and low dielectrical loss. Barium titanate powder has high dielectric constant and low dielectrical loss. The dielectric constant of BaTiO₃/PS composites increases with the increase of BaTiO₃ content. When the dielectric constant of materials are the same, BaTiO₃/PS composites is less dense and lighter than that of polystyrene foam, which indicates that the addition of BaTiO₃ can realize the weight reduction of dielectric materials.