Synthesis and characterization of novel benzoxazine monomers containing allyl groups and their high performance thermosets

Two novel benzoxazine monomers containing allyl groups: 3-ally1-3,4-dihydro-2H-1,3-benzoxazine and bis(3-allyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane have been synthesized from phenol and Bisphenol A with allylamine and formaldehyde. Their DSC exhibit two exotherms at ca. 145 degreesC and at ca. 220 degreesC which correspond to allyl and oxazine thermal polymerization, respectively. Both monomers undergo thermal cure with the formation of thermosets having excellent thermomechanical properties. These thermosets exhibit higher T-g (ca. 300 degreesC), maintain their storage moduli at higher temperature, and have better thermal stability than the corresponding polybenzoxazines without allyl groups.