Synthesis of poly(enaminonitriles) containing arylate and aramide units, and their thermal properties

Various aromatic diamines with preformed arylate and aramide linkages were obtained by the reaction of p ‐nitrobenzoyl chloride with aromatic diols and diamines, and terephthaloyl chloride with p ‐nitrophenol and p ‐nitroaniline, followed by hydrogenation. New poly(enaminonitriles) containing arylate or aramide units in the main chain were prepared by reacting p ‐bis(1‐chloro‐2,2‐dicyanovinyl)benzene ( 2 ) with the corresponding ester‐ or amide‐containing aromatic diamines. These polymers possess intrinsic viscosities of 0.38–0.53 dL/g. They are easily soluble in polar aprotic solvents such as dimethyl sulfoxide, N , N ‐dimethylformamide and N ‐methyl‐2‐pyrrolidone. Hard and brittle films were easily cast from DMF solutions. These polymers show a broad exothermic peak in differential scanning calorimetry and undergo a curing reaction around 350°C to form insoluble materials. Almost all the poly(enaminonitriles) exhibited no appreciable decomposition below 400°C, 10% weight loss being recorded above 450°C, and a good thermal stability of 83–92% residual weight at 500°C.