Phthalonitrile‐based high temperature resin

An aromatic, diether‐linked phthalonitrile resin, prepared from 4,4′‐bis(3,4‐dicyanophenoxy)biphenyl, exhibits excellent thermo‐oxidative properties. The resin is easily processed from the melt of the monomer in a controlled manner as a function of the amine curing agent and processing temperatures. Polymerization occurs by a cyclic addition reaction without the formation of volatile by‐products. The polymerization reaction can be stopped at a prepolymer stage. The prepolymer can be stored indefinitely at ambient conditions without further reaction. The modulus and viscoelastic properties of the resin were found to be a function of the postcuring conditions.