A Novel Synthetic Process of Polyimide/Poly (Methyl Silsesquioxane) Hybrid Materials with Nano/Micro Pore Structures

摘要

A novel synthetic process for multi-porous polyimide (PI)/poly (methyl silsesquioxane) (PMSSQ) hybrid malerial has been studied via supercritical CO_2 technology. The end groups of PI precursors were modified by coupling agent to be hybridized with alkoxysilanes and became PMSSQ precursors. PI/PMSSQ hybrid precursor solution was spun on a silicon wafer substrate for film forma-lion. The PI precursor segment was imidized and micro-pores were developed by removal of by-product, CO_2 via. supercritical CO_2 media. The PMSSQ precursor segment was cured and nano-pores were generated by supercritical extraction. Average micro-pore size and nano-pore size were 10 mu m and 40nm respectively. The dielectric, constant of the multi-porous PI/PMSSQ hybrid film was calculated to 2.5.