Research on Moulding Process and Dielectric Property of Polyimide Foam

Foaming moulding process, cellular structure and dielectric property of polyimide (PI) foam which has been prepared by esterification method were discussed. Research results showed that the cell of prepared PI foam was well-distributed and its pore volume and porosity were bigger by microwave heating when methanol was used as the foaming agent and its content in the polyester ammonium salt (PEAS) precursor powder was 13-15%; meanwhile, the dielectric constant and loss factor of PI foam were lower.