Eco‑friendly fully bio‑based polybenzoxazine‑silica hybrid materials by sol–gel approach

Abstract
In the present work, a high thermal and fame-retardant polybenzoxazine-silica hybrid material has been synthesized using renewable raw materials (including eugenol and furfurylamine) via a greener sol–gel-based approach. Inorganic com�ponent tetraethoxysilane (TEOS) was introduced into eugenol benzoxazine (BZ–E–F) with the help of (3-mercaptopropyl) trimethoxysilane (MPTMS) as a coupling
agent viz thiol-ene click approach among the mercapto group (–SH) of MPTMS and allyl functional group in the eugenol. The developed BZ–E–F monomer and PBZ–E–F hybrids are characterized to check the molecular structures, curing behaviour, thermal stability and fame-retardant properties. The thermal studies reveal that the char yield increases to 67.54 from 41.32 and LOI increased to 44.52 from 34.03
for PBZ–E–F silica hybrid. The thermal and fame-resistant studies strongly sug�gest that the prepared sustainable and eco-friendly PBZ silica hybrid can be used to replace the petroleum-based polymeric materials for better thermal and fame�resistant applications.