Synthesis and thermal properties of poly(enaminonitriles) containing flexible ether units

Poly(enaminonitriles) containing flexible alkyl ether units were prepared by reacting p ‐bis(1‐chloro‐2,2‐dicyanovinyl)benzene with various α,ω‐bis(4‐aminophenoxy)alkanes in N ‐methyl‐2‐pyrrolidone (NMP). All the polymers are soluble in polar aprotic solvents such as N , N ‐dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N , N ‐dimethylacetamide (DMAc) and NMP as well as in common organic solvents such as tetrahydrofuran and acetone. High molecular weight polymers possessing inherent viscosities in the range of 0.82–1.20 dL/g were obtained and tough films were cast from a DMF solution. They showed a large exotherm around 340°C attributable to the chemical changes of the dicyanovinyl group. Thermogravimetric analyses exhibited a good thermal stability with a 10% weight loss around 450°C and 73–88% residual weight at 500°C under nitrogen.