Synthesis of poly(amido amine)-derived dendrimers with pendant benzoxazine groups and their thermal behavior

Two novel dendrimer-derived compounds with pendant benzoxazine, named 0G benzoxazine (0G BOZ) and 1G benzoxazine (1G BOZ), were prepared using 0G poly(amido amine) (PAMAM) and 1G PAMAM, phenol, and paraformaldehyde. Effects of different generations of PAMAM on curing kinetics and thermal properties were investigated. Differential scanning calorimetric (DSC) measurements of the 0G BOZ and 1G BOZ were carried out at different heating rates of 5, 10, 15, and 20 K/min. Kinetic analysis by Kissinger's and Ozawa's method revealed the activation energy (Ea) of 0G BOZ were 109.1 and 109.3 kJ mol-1, respectively, and those of 1G BOZ were 88.0 and 91.4 kJ mol-1. The autocatalytic kinetic model was found to be the best description of the investigated curing reactions. In addition, the predicted curves from our kinetic models fit well with the nonisothermal DSC thermograms. Thermogravimetrical analysis of cured resin of 0G BOZ and 1G BOZ showed that the char yields of 0G BOZ and 1G BOZ were 37.6 and 26.3%, respectively. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012