Sulfur Radical Transfer and Coupling Reaction to Benzoxazine Groups: A New Reaction Route for Preparation of Polymeric Materials Using Elemental Sulfur as a Feedstock

Abstract

A novel approach to preparing polymeric materials using elemental sulfur as a feedstock through the newly developed sulfur radical transfer and coupling (SRTC) reaction is reported herein. Polybenzoxazines with high sulfur contents are prepared using the SRTC reaction with benzoxazine compounds as the radical acceptors. The reactions between elemental sulfur and benzoxazine rings are analyzed with Fourier transform infrared (FTIR), ¹ H NMR, and ¹³ C DEPT spectroscopies to elucidate the SRTC reaction mechanism. Moreover, the prepared polybenzoxazine-sulfur hybrid materials show attractive repairing properties based on the dynamic S-S linkages. An effective reaction mechanism and the prepared repairable sulfur-possessing polymeric materials are demonstrated.

Keywords: benzoxazine; polysulfides; sulfur radical transfer and coupling reaction; vulcanization.