DEVELOPING OF MATLAB APPLICATION FOR DETERMINING THE REACTION KINETICS OF RUBBER VULCANIZATION PROCESS

Abstract

Rubber vulcanization is kinetically a complex process, since it consists of two simultaneous reactions: curing and degradation. To determine reaction kinetics, it is necessary to determine a kinetic model which describes the process adequately. Proposed kinetic model has six adjustable parameters. In order to determine kinetic parameters of the proposed kinetic model, commercially available rubber gum was used. Oscillating disc rheometer was used to investigate experimental dependence of torque on time, at six temperatures in the range from 130 to 180 °C, with a step of 10 °C. Matlab application, built via App Designer feature, was developed in order to fit the experimental data to the proposed kinetic model. Developed Matlab application, consisting of two tabs, enables user to upload raw rheometer data, perform manual fitting or automatic fitting (manual or automatic estimation of initial values of adjustable parameters), test the effect of constant values of some kinetic parameters on the overall quality of fit, visualize the dependence of kinetic parameters on temperature and to determine the values of Arrhenius expression for curing and degradation process. Both fitting methods were proven to be efficient; overall determination coefficient and MAPE value for automatic and manual fitting methods were >0.99 and <1%, and >0.999 and <1%, respectively. Arrhenius parameters were also determined with high accuracy (R2>0.98). Developed application enables simple and efficient determination of kinetic parameters by means of different fitting methods, simultaneous fitting of data on all temperatures, and testing the effect of constant kinetic parameters values on fitting results