Synthesis of New Polysilsesquioxane‐Reinforced Renewable Benzoxazine Hybrid Thermosets With Improved Thermal Performance

A novel renewable silane‐based tri‐functional benzoxazine (RES‐3aptms) was successfully obtained from resveratrol, 3‐aminopropyltrimethoxysilane and paraformaldehyde and characterized by Nuclear Magnetic Resonance Spectroscopy. The chemical reaction conditions for the hydrolysis and condensation of the alkoxysilane groups in RES‐3aptms were successfully optimized, enabling controlled sol–gel and oxazine ring‐opening processes. Subsequently, a series of novel silsesquioxane‐based renewable tri‐functional resin systems were prepared by combining the precursor with either a resveratrol‐based epoxy resin (RES‐ech) or a resveratrol‐ and furfurylamine‐based benzoxazine (RES‐fa) at a 1:1 molar ratio. The thermal and morphological properties of these materials were evaluated, showing a lamellar nano‐structural morphology of outstanding thermal resistance, high char yields (~80%, at 800°C under N 2 ), and glass transition temperatures (Tgs) around 300°C. Regarding contact angle measurements, the polybenzoxazines and the benzoxazine/benzoxazine copolymer revealed higher hydrophobic surfaces (around 85°) than the benzoxazine/epoxy copolymer (around 78°). The resveratrol‐based thermosets demonstrated that reactive incorporation of polysilsesquioxane structures improves char and thermal resistance integrity, suggesting potential applications for high‐performance components.