Nicotinic-based poly(amide-ether-imide)s: A new category of soluble, heat-resistant, and flame-retardant polyimides

Abstract

A novel fully aromatic diamine containing highly pyridine units, amide, and ether groups was prepared via two-step reactions: nucleophilic substitution reaction of 2,6-diaminopyridine with 6-chloronicotinoyl chloride led to preparation of a dichloro-diamide compound. Subsequent reaction of this compound with 5-amino-1-naphthol resulted in synthesis of the particular diamine. After complete characterization, polycondensation reaction of the diamine with different dianhydrides led to preparation of related poly(amide-ether-imide)s. The polymers were characterized and their physical and thermal properties including viscosity, solubility, water absorption, thermal behavior and stability, flame retardancy, and crystallinity were studied. The nicotinic-based poly(amide-ether-imide)s showed high heat and flame resistant, low water absorption in conjunction with improved solubility in polar solvents.