Synthesis and characterization of Fluid 1,3-benzoxazine monomers and their thermally activated curing

Novel mono- and difunctional aliphatic oxyalcohol-based benzoxazines have been synthesized and characterized in detail. Molecular structures of the monomers were investigated by spectral analysis. The obtained benzoxazine monomers exhibit fluidic behavior, which makes them particularly useful for many applications compared to other traditional benzoxazines. Differential scanning calorimetry was used to monitor the thermal crosslinking behavior of synthesized monomers. Monoand bifunctional benzoxazine monomers exhibited low curing exhothermic peak with the onset around 173 and 180 °C, respectively. Relatively, low ring-opening polymerization temperature was due to the hydroxyl groups present in the structure of the monomers. The hydrogen bonding of hydroxyl groups may cause alignment of the monomers in the liquid state. Thermal stabilty of the polybenzoxazines was studied by thermogravimetric analysis.