Synthesis of novel benzoxazines containing glycidyl groups: A study of the crosslinking behavior

Benzoxazines derived from aniline and 4‐hydroxybenzoic acid and from phenol and 4‐aminobenzoic acid were prepared with two different synthetic approaches. When the carboxylic group reacted with epichlorohydrin, glycidylic derivatives M‐1 and M‐2, respectively, were obtained. The ring opening of benzoxazine and epoxy took place simultaneously with no catalyst for both monomers. Likewise, both ring‐opening polymerizations took place when boron trifluoride monoethylamine (BF3·MEA) or 4‐(N,N‐dimethylamino)pyridine was used as a catalyst for M‐1. However, for M‐2, when BF3·MEA was used as a catalyst, the epoxy and benzoxazine ring openings could be distinguished, and a polyether intermediate containing benzoxazine side chains could be obtained.