Silicon-Containing Polyimide-Based Polymers with High Temperature Stability

A study was conducted to demonstrate the synthesis of novel Si-containing polyimides and on the characterization of their thermal properties. The synthesis was performed in three steps, such as monomer synthesis, polymerization, and thermal treatment. A method was developed in the first step to synthesize isomerically pure diamino silanes and diamino siloxanes in high yields starting from bromoaniline. Via reaction of the obtained monomers with different aromatic dianhydrides novel silicon-containing polyamilic acid-based compounds were obtained and converted by a final heat treatment into polyimides with excellent high-temperature stability. The prepared diamines were first dissolved in an aprotic dipolar solvent, such as dimethyl acetamide (DMAc) or N-methyl pyrrolydone (NMP) and the dianhydride was added in solid form to the diamine solution to obtain a polyamic acid.