POLYISOPHTHALAMIDES WITH PENDANT 3,4,5,6-TETRACHLOROPHTHALIMIDE GROUPS

New polyamides containing pendant chlorinated phthalimide groups have been synthesized by solution polycondensation of various aromatic diam ines with 5-(3,4,5,6-tetrachlorophthalimide)isophthaloyl chloride. The se polymers are soluble in such polar amidic solvents as N-methyl-2-py rrolidinone and N,N-dimethylformamide and give transparent flexible fi lms by casting from solutions. They show high thermal stability with a decomposition temperature above 400 degrees C and no glass transition up to 350 degrees C. They have low dielectric constants in the 3.6-4. 0 range and good tensile properties.