Synthesis and characterization of novel mussel-inspired benzoxazines by thiol-benzoxazine chemistry

A catechol-based benzoxazine copolymer is reported via a new approach using an oxazine-thiol reaction. The main chain benzoxazine precursor was obtained via the classic benzoxazine synthesis methodology using the raw chemicals catechol, formaldehyde, and 4,7,10-trioxa-1,13-tridecanediamine. The countercomponent was synthesized from poly(ethylene glycol) methyl ether via the Fischer esterification reaction. The obtained reactive catechol-based benzoxazine was then reacted in mild conditions with polymeric thiol precursor to obtain a copolymer structure. The precursors and the resulting structure were characterized by thermal and spectral analyses using DSC, TGA, FT-IR, H-1 NMR, and GPC. Film formation was also demonstrated with unreacted oxazine ring units in the copolymer, and the ring opening polymerization temperature was lower than that corresponding to the benzoxazine precursor.