Comparison of calculating parameters methods of vulcanization process kinetic equations

The article presents algorithms for numerical calculation of kinetic parameters of the vulcanization process using two methods. Since the kinetic parameters of vulcanization strongly depend on the rubber compound formula-tion, two compounds with different compositions were considered in the study. The kinetics of vulcanization is described using the concept that the process consists of three first-order reactions: formation of stable bonds between rubber macromolecules, formation of unstable bonds, and destruction of unstable bonds (reversion). The rate constants of these reactions are described by the Arrhenius equation. The calculation algorithms include analysis of experimental rheometer curves, determination of kinetic parameters of the induction period, calculation of kinetic parameters of three reactions, and verification of the parameters found by numerical modeling of isothermal vulcanization at different temperatures. The difference between the two approaches to calculating kinetic parameters lies in determining pre-exponential factors and activation energies of the Arrhenius equations. According to the first approach, the reaction rate constants are first determined, then the pre-exponential factors and activation energies are found. In the second variant, direct determination of the reaction rate constants is not required. It was found that for a rubber compound not prone to reversion, both approaches lead to an insignificant error. Calculation of kinetic parameters for a rubber compound with a pronounced reversion period gives a large error in both cases, which indicates the complexity of reversion modeling. Based on the conducted research, a conclusion was made about the need for a correction factor when calculating the experimental state of cure based on rheometer readings. It is also necessary to develop restrictions when searching for optimal kinetic parameters.