A novel benzoxazine containing maleimide and carboxylic moieties, 1[3-(4-carboxylphenyl)-3,4-dihydro-2H-benzo[e][1,3]-oxazin-6-yl]maleimid e (Mal-Bz-Co), was synthesized and the structure was identified by H-1-NMR and FTIR. Mal-Bz-Co exhibited good solubility in common organic solvents. The cure behavior of Mal-Bz-Co and cocure behavior of Mal-Bz-Co with o-cresol formaldehyde epoxy resin were investigated by differential scanning calorimetry. Results indicated that Mal-Bz-Co showed a single curing exothermic peak at about 238.3 degrees C. However, the maximum curing temperature (TO decreased to 146.1 degrees C when Mal-Bz-Co cocured with o-cresol formaldehyde epoxy resin in the molar ratio of 1 : 1. The T-p was about 92 degrees C lower than that of Mal-Bz-Co. Thermogravimetric analysis showed that high-decomposition temperature and char yield were observed for the cured resins of Mal-Bz-Co and Mal-Bz-Co/o-CFER. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 705-710, 2010