Synthesis And Curing Kinetics Of Two Benzoxazine Containing DOPO

Recently, the demand for high performance materials has increased tremendously due to the development of electronics and aerospace industries. Benzoxazine, as a new type of phenolic resin, has not only good thermal properties, electronic properties, flame retardant of traditional phenolic resin, but also has many attractive properties, such as molecular design flexibility, good mechanical property, low water absorption, low porosity, approximate zero shrinkage, low dielectric, etc.At present, among the studies of benzoxazine resin, the development trend is preparing thermal stability and flame retardant benzoxazine. By taking advantage of the molecular design flexibility of benzoxazine, we synthesize two kinds of high heat resistant and flame retardancy benzoxazine monomers DOPO-BZ-1and DOPO-BZ-2though introducing DOPO group into benzoxazine structure. The brief contents are shown as follows:Firstly, the DOPO based benzoxazine DOPO-BZ-1was synthesized and its curing kinetics was studied by non-isothermal differential scanning calorimetry at different heating rate. Three different methods (Kissinger, Ozawa and Flynn-Wall-Ozawa) were employed to research the cure kinetics of DOPO-BZ-1, the apparent activation energy were104.3kJ/mol,107.5kJ/mol and102.7kJ/mol, respectively. The autocatalytic kinetic model was found to be the best description of the investigated curing reaction. The reaction order m and n were0.51and0.85respectively. Non-isothermal DSC curves obtained from the experimental data showed a good agreement with that theoretically calculated. In addition, the appropriate curing reaction condition was obtained. The splines made from DOPO-BZ-1and PAF blends were used for flame retardant test, the LOI enhanced from26to37, this indicated that DOPO-BZ-1had excellent flame retardancy.Secondly, the DOPO based benzoxazine DOPO-BZ-2was synthesized and its curing kinetics was studied by non-isothermal differential scanning calorimetry at different heating rate. Three different methods (Kissinger, Ozawa and Flynn-Wall-Ozawa) were employed to research the cure kinetics of DOPO-BZ-2, the apparent activation energy were107.8kJ/mol,110.9kJ/mol and102.4kJ/mol, respectively. The autocatalytic kinetic model was found to be the best description of the investigated curing reaction. The reaction order m and n were0.52and1.03respectively. Non-isothermal DSC curves obtained from the experimental data showed a good agreement with that theoretically calculated. In addition, the appropriate curing reaction condition was obtained. The splines made from DOPO-BZ-2and PAF blends were used for flame retardant test, the LOI enhanced from26to38, this indicated that DOPO-BZ-2had excellent flame retardancy.