Synthesis and Properties of a High-Temperature Naphthyl-Based Phthalonitrile Polymer

A novel, high-temperature, naphthyl-based phthalonitrile polymer is prepared. The phthalonitrile monomer, namely, 2,7-bis(3,4-dicyanophenoxy) naphthalene (BDCN), is synthesized from the reaction of 2,7-dihydroxynaphthalene (DHN) with 4-nitrophthalonitrile (NPN), and its curing behavior with 1,3-bis(4-aminophenoxy) benzene (APB) is investigated by DSC. The high-temperature BDCN polymer is prepared via a two-step approach: the preparation of the BDCN prepolymer and the post-cure of the BDCN prepolymer at elevated temperatures. The BDCN polymer might form a polypyrrole structure as revealed by FTIR spectroscopy, and exhibits a high storage modulus, high glass-transition temperature, and outstanding thermal stability, along with long-term oxidative resistance.