利用非溶剂诱导相分离法制备低介电常数聚酰亚胺微孔薄膜

Preparation of Porous Polyimide Film with Low Dielectric Constant by Nonsolvent Induced Phase Separation

利用非溶剂诱导相分离法,制备了一种低介电常数聚酰亚胺(PI)微孔薄膜。扫描电镜观察表明,聚酰亚胺微孔薄膜中泡孔均匀,其平均孔径在6~28μm之间。随着聚酰胺酸(PAA)浓度的增大及凝固浴温度的升高,所制得的聚酰亚胺微孔薄膜的孔隙率和平均孔径均增大。介电性能分析表明,聚酰亚胺微孔薄膜的介电常数明显下降,当孔隙率为80%时,聚酰亚胺微孔膜的介电常数(1 MHz)为1.81。拉伸性能测试表明,随着孔隙率增加,聚酰亚胺微孔膜的拉伸强度和拉伸模量均逐渐下降,但断裂伸长率增大。

In this paper, one kind of porous polyimide （PI） film with low dielectric constant was prepared by nonsolvent induced phase separation method. SEM observations show that the pores are homogeneously dispersed and their average pore size is between 6 μm and 28 μm. With increasing of the polyamic acid （PAA） concentration and enhancing of the temperature of coagulation bath, the porosity and average pore size of the porous PI films are increased. Dielectric property analysis shows the dielectric constant of the porous PI films is obviously decreased. When the porosity of the porous film is 80%, its dielectric constant （1 MHz） is 1.81. Tensile test shows that the tensile strength and modulus of the porous PI films are decreased with the increase of porosity, while the elongation at break of the films is increased.