Synthesis and Characterization of a Hybrid Material Based on a Trimethoxysilane Functionalized Benzoxazine

Abstract

A polybenzoxazine / polysiloxane hybrid has been prepared by sol-gel process and ring-opening polymerization. For this purpose, first a functionalized benzoxazine was synthesized from bisphenol A, paraformaldehyde and 3(trimethoxysilyl) propylamine, with initial molar ratio 1:4:2, and 95% yield. The structure of the monomer was characterized by Fourier Transform Infrared, Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The sol-gel process and curing behavior have been studied by FTIR spectroscopy and Differential Scanning Calorimetry (DSC). The Dynamic Mechanical Analysis (DMTA) of the hybrid material(Bz-PSi) showed higher Tg and storage modulus respect to the conventional polybenzoxazine (Bz-BA). Also, the Thermogravimetric Analysis (TGA) revealed better thermal stability. The high Limiting Oxygen Index (LOI) values (about LOI = 32)confirmed similar effective flame retardance properties of the hybrid material respect conventional benzoxazine.