Synthesis and properties evaluation of novel halogenated polyimides designed to prepare functional polymers

Three new aromatic polyimides containing one or two replaceable halogen atoms in the repeat unit have been prepared by one-pot polycondensation at high temperature from dianhydrides and diamines containing halogen atoms. The halogenated polyimides exhibited good thermal properties and great solubility in a wide range of organic solvents, which make them good candidates to prepare functional polymers. They also showed film-forming capabilities, good mechanical properties, and a very low ability to take water, with values of only around 1% water uptake. To show the usefulness of these polyimides as functional polymers, the halogen group of two of them was successfully replaced by 4-tert-butyl phenyl or 4-tert-butyl phenyl ethynyl groups by a Suzuki or a Sonogashira reaction, respectively.