Modified three-step Synthesis and Polymerization of Monofunctional 1, 3-Benzoxazine

Abstract

A monofunctional 1,3-benzoxazine was synthesized via three-step technique involving condensation of 4- nitroaniline with 2-hydroxybenzaldehyde to obtain an Imine compound which is reduced using NaBH 4 to obtain 2 -hydroxybenzylamine that undergo ring -closure reaction with methylene bromide to obtain the target monofunctional 1,3 -benzoxazine. The structure of the monofunctional 1,3 -benzoxazine was confirmed by FT -IR, 1H and 13C NMR spectra and Mass spectroscopy. The 1,3 -benzoxazine compound was polymerized via thermally activated ring opening which affords a polybenzoxazine with 5% and 10% weight loss temperatures of 208 and 237°C, degradation temperature of 322°C and a char yield of 34% at 800°C indicating overall moderate thermal properties for the synthesized polybenzoxazine.