Combining benzoxazine and ketene chemistries for self-healing of high performance thermoset surfaces

A novel strategy for the synthesis and characterization of self-healable polybenzoxazine-based high performance thermoset surfaces is presented. The method involves the preparation of polymeric benzoxazine precursors from simple chemicals such as bisphenol A, formaldehyde, polyetheramines (Jeff amines) and subsequent ring opening polymerization followed by light-induced oxoketene formation. The structure and molecular weights of precursor polymers were characterized by FTIR, ¹H NMR, and GPC, respectively. Successful self-healable formulations were prepared using bisbenzodioxinone (5 wt%) in the precursors, which were shown to undergo thermally activated curing by the ring opening polymerization of benzoxazines. The thermal properties of the polymers were also investigated by using DSC and TGA. Light-induced self-healing on the surface of the cured specimens was demonstrated and quantified by AFM analysis. The thermal stability differences of the cured and healed products were also investigated and compared.