A new bio-based thermosetting with amorphous state, sub-zero softening point and high curing efficiency

In this work, bio-based tyramine was exploited to prepare a novel phthalonitrile monomer (L-CN) with amorphous characteristics, sub-zero softening point (−16 °C) and high curing reactivity. Compared with the control compounds, it showed that amorphous structure and low softening point of L-CN cannot be simply attributed to the introduction of flexible aliphatic chain. It is proposed that the inhibited crystallization of the PN monomer can be understood by the multi-competitive supramolecular interactions as suggested by 1HNMR, in-situ FTIR and molecular dynamics simulation. Furthermore, the cured resin exhibited excellent thermal and thermomechanical properties at relatively low post-cured temperature due to the strong nucleophilicity and mobility of the aliphatic amine.