Facile synthesis of new thermally stable and organosoluble polyamide-imides based on non-coplaner phosphorus and silicon containing amines

Abstract

Two new kinds of diamines, 3-[bis-(3-aminophenyl)-phosphinoyl)-phenyl]-3-(triphenyl-phosphoranylidene)-pyrrolidene-2,5-dione, (DAP) with phosphorus moiety and bis-(5-amino-naphthalene-1-yl) dimethyl silane (DAS) with silicon moiety are synthesized. A series of novel aromatic polyamide-imides (PAIs) are prepared from three dicarboxylic acids and synthesized diamines. The phosphorus and silicon containing diamines and all polymers are characterized by FT-IR, NMR spectroscopic techniques and elemental analysis. The polymers obtained have good thermal stability and glass transition temperature (Tg) in the range of 254–315∘C. All these novel polyamide-imides (PAIs) contain 10% weight loss at the temperature above 506∘C and more than 59% residue at 600∘C in nitrogen atmosphere. The resulting polymeric films exhibit high optical transparency and inherent viscosity in the range of 0.68 to 0.79 dL/g. These polymers are found to be soluble in aprotic polar solvents such as NMP, DMSO, DMF and DMAc. Wide angle X-ray diffraction revealed that these polymers are predominantly amorphous in nature.