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

Abstract

AbstractVarious 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.