Synthesis and Properties of Bio‐Based High‐Temperature Oxydianiline Phthalonitrile Resins

High temperature resins are of interest in many applications including use in extreme environments including atmospheric reentry. Finding methodology to reduce additives while increasing processability for these resins while simultaneously relying less on petroleum‐based products is of high importance so that large‐scale manufacturing becomes more accessible. Herein, we report the synthesis of a series of new vanillin‐oxydianiline (Vn‐ODA) based phthalonitrile (PN) resins. These resins contain the bio‐based monomer, vanillin, along with internal initiators via an imine linkage formed by the vanillin and ODA molecules, eliminating the requirement for additives to initiate curing. The resulting resins exhibit good thermo‐oxidative properties with char yields under N 2 above 75% and thermolytic degradation above 490°C under air. Furthermore, the meta ‐ and para ‐ resins exhibit promising processing windows with low melt temperatures and a T g above final cure temperature.