Synthesis and properties of a sustainable, vanillin‐based <scp>p</scp>hthalonitrile resin

Abstract The renewable and biosynthetic molecule, vanillin, was used in the preparation of a new phthalonitrile resin (PN), containing two phthalonitrile groups without pre‐modification of the vanillin structure. This PN resin was characterized thoroughly by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR) spectroscopy, rheometry, Fourier transform infrared spectroscopy (FTIR), and single‐crystal X‐ray diffraction (XRD). The monomer exhibited excellent rheometric viscosities below 250 cP at processing temperatures and a good pot life. After complete curing, the PN polymer exhibited thermal stability above 500°C, a glass transition temperature ( T g ) above the final postcure temperature of 380°C, and exceptional retention of structural integrity. These results highlight a vanillin‐derived PN resin is an excellent candidate for a variety of applications where high temperature and mechanical stability over a large temperature range are required.