二氧化碳发泡制备低介电聚酰亚胺/POSS复合泡沫

Preparation of low dielectric polyimide/POSS composite foam by carbon dioxide foaming

为了满足快速发展的通讯行业对低介电材料的需求,多孔材料因其低介电的特性,受到了广泛的关注。二氧化碳发泡材料是一种重要的多孔材料,其制备过程使用物理发泡剂,经济环保。为了制备低介电聚酰亚胺(PI)材料,我们使用二氧化碳发泡方法制备PI泡沫,研究无机粒子多面体低聚倍半硅氧烷(POSS)的添加对复合泡沫孔结构的影响。系统研究了在不同浸润条件和发泡条件下泡沫形貌的变化规律,制备出平均孔径最小为0.46μm的复合泡沫以及最高孔隙率为45%的复合泡沫。POSS的引入以及内部空气的存在降低了PI/POSS复合泡沫的介电常数,当PI/POSS复合泡沫的孔隙率为45%时,介电常数为2.35。在1~106 Hz的频率范围内,PI/POSS复合泡沫的介电常数保持稳定,同时可以保持发泡前30%的拉伸强度。

In order to meet the demand for low dielectric materials in the rapidly developing communication industry,porous materials have received widespread attention due to their low dielectric properties.Carbon dioxide foamed material is an important porous material,and its preparation process is economical and environmentally friendly using physical blowing agents.In order to prepare low dielectric polyimide(PI)materials,we used the CO 2 foaming method to prepare PI foams,and investigated the effect of the addition of inorganic particle polyhedral oligosilsesquioxane(POSS)on the pore structure of the composite foams.We systematically investigated the change rule of foam morphology under different saturation and foaming conditions,and prepared composite foams with an average pore size of 0.46μm and a maximum porosity of 45%.The introduction of POSS and the presence of internal air reduces the dielectric constant of the PI/POSS composite foam,which is 2.35 at a porosity of 45%.The dielectric constant of the PI/POSS composite foam remains stable in the frequency range of 1~106 Hz,while maintaining 30%of the pre-foam tensile strength.