Synthesis and polymerization of disiloxane Si–O–Si-linked phthalonitrile monomer

A novel low melting highly hydrolytically stable phthalonitrile monomer containing Ar–Si–O–Si–Ar bonds with T g = 4 °C exhibits good rheological properties. Its cured resin possesses high heat deflection temperature ( T hd = 471 °C) and demonstrates high thermal and thermooxidative stabilities ( T 5% = 503 °C, TOS 5% = 495 °C, Y c = 76%) that are typical of phthalonitrile matrices.