SIMULATION OF KINETIC PARAMETRS OF VYNYL ESTER RESIN SAMPLES WITH DIATOMITE AND DIMETHYL METHYLPHOSPHONATE FILLERS

This article presents the results of predicting the kinetic properties of composite materials based on vinyl ester resin (VER) with the addition of diatomaceous earth and dimethyl methylphosphonate (DMMP) using the Netzsch Kinetics Neo software. The VER samples were synthesized at the University of Science and Technology of China (Hefei, China) as part of a project funded under a targeted grant program. The kinetic characteristics of four samples were predicted based on the results of thermogravimetric analysis: Pure VER, VER + DE – a VER sample with a diatomite concentration of 25%, VER+DE/DMMP – VER with physically mixed DMMP and diatomite at concentrations of 12.5% and 12.5%, respectively, and VER + DE@DMMP – a sample with DMMP immobilized in the pores of diatomite (25%). Models were selected in the Netzsch Kinetics Neo software. For the pure sample, the model corresponded to a simple first-order reaction; for VER with diatomite, independent reactions (simple and diffusion); for VER+DE/DMMP and VER+DE@DMMP, autocatalytic A2 and A3, and diffusion D3. Simulations were performed for the degradation time of the composites under isothermal conditions in the range from 100 to 400 degrees, as well as for the temperature and time of decomposition onset and the attainment of various degrees of degradation under dynamic conditions at a heating rate of 120 K/min, simulating a fire scenario. The results of the analysis showed that pure VER decomposes very slowly at low temperatures, but quite rapidly at high temperatures, compared to the other samples. The VER+DE/DMMP and VER+DE@DMMP samples exhibit a higher decomposition rate in the initial stages, whereas mass loss slows down at high temperatures. In the dynamic mode, the pure VER sample showed the shortest decomposition time and the lowest temperature. In the immobilized sample, decomposition proceeds slightly faster than in the diatomite sample. The composite with physically mixed diatomite and DMMP demonstrated intermediate decomposition temperatures and times. The results obtained open up opportunities for the development of new fire-resistant materials with controllable functional properties.