New poly(amide-imide) siloxane copolymers by polycondensation

Some new poly(amide-imide) siloxane copolymers have been synthesized by solution polycondensation of some aromatic diamines with siloxanic diacids having preformed imide rings. Two polycondensation techniques were used: polycondensation of aromatic diamines with diacid chlorides and direct polycondensation of aromatic diamines with diacids in the presence of organic phosphites, following the Yamazaki–Higashi phosphorylation technique. In all cases the reactions were carried out using equimolecular amounts of the two monomers, in polar aprotic solvents and inert atmosphere. The obtained compounds were characterized by elemental C, H and Si analysis, solubility tests, IR and 1H-NMR spectrometry. Thermogravimetric curves were also recorded. All data agree with the proposed structures.