Hybrids from silazane and allyl-containing benzoxazine for low-curing temperature and high-flame retardance

Silicon hybrid benzoxazine has good flame retardance, but generally these hybrid polymer' curing temperature is higher than 220 degrees C, limiting its application in the field of electronics. In this study, under Nickel acetylacetonate catalyzed, a new hybrid benzoxazine was synthesized using the copolymerization of polysilazane and allyl containing benzoxazine. Differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy (FTIR) studied the curing behavior of this hybrid benzoxazine. The results of DSC and FTIR indicated that the curing temperature of this hybrid benzoxazine can decrease from 269 to 182 degrees C, the main reaction with this hybrid benzoxazine is amine-catalyzed oxazine ring- opening and the hydrosilylation reaction. The thermal stability of hybrid benzoxazine after cured was studied by a thermogravimetric analyzer. The results of thermogravimetric experiments demonstrated that this hybrid benzoxazine's char yield can increase from 25.57% to 66.11% (159% increase). The flame retardancy of glass fiber reinforced hybrid benzoxazine was studied by the UL-94 flame test. The glass fiber reinforced hybrid benzoxazine composite show a V-0 result in the UL-94 test. This work provides a new hybrid benzoxazine with low-curing temperature, ultrahigh char yield, and great flame retardance.