A series of polyamides and poly(amide-imide)s was prepared by direct polycondensation of ether and nitrile group containing aromatic diamines with aromatic dicarboxylic acids and bis(carboxyphthalimide)s respectively in N-methyl 2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. New diamines, such as 2,6-bis(4-aminophenoxy)benzonitrile and 2,6-bis(3-aminophenoxy)benzonitrile, were prepared from 2,6-dichlorobenzonitrile with 4-aminophenol and 3-aminophenol, respectively, in NMP using potassium carbonate. Bis(carboxyphthalimide)s were prepared from the reaction of trimellitic anhydride with various aromatic diamines in N,N′-dimethyl formamide. The inherent viscosities of the resulting polymers were in the range of 0.27 to 0.93 dl g−1 in NMP and the glass transition temperatures were between 175 and 298 °C. All polymers were soluble in dipolar aprotic solvents such as dimethylsulfoxide, dimethylacetamide and NMP. All polymers were stable up to 350 °C with a char yield of above 40 % at 900 °C in nitrogen atmosphere. All polymers were found to be amorphous except the polyamide derived from isophthalic acid and the poly(amide-imide)s derived from diaminodiphenylether and diaminobenzophenone based bis(carboxyphthalimide)s.
Dr. Akanksha Saxena Pandit, Prabhakaran, P. V., V Rao, L., and Ninan, K. N., “Synthesis and characterization of polyamides and poly (amide-imide) s derived from 2, 6-bis (3-aminophenoxy) benzonitrile or 2, 6-bis (4-aminophenoxy) benzonitrile”, Polymer international, vol. 54, pp. 544–552, 2005.