Characterization of Carbamide Peroxide: Stability Studies , and Degradation Kinetics under Isothermal Conditions for Industrial Application

Abstract

Background: Carbamide peroxide (CP) is a hydrogen peroxide derivative bonded with urea. It is a solid substitute for liquid hydrogen peroxide in the chemical, cosmetics, and pharmaceutical industries, mainly as a disinfectant and bleaching application. However, it has an unstable nature, and there are scant studies on CP thermal analysis. Objective: This study focuses on CP thermal analysis and degradation behavior. Methods: CP was characterized by differential scanning calorimetry, thermogravimetric analysis, Fourier-transformed infrared, diffraction by X-ray, as well as, thermal and photodegradation was determined by ultraviolet spectrophotometer. Results: CP was characterized with a sharp endothermic event (88.50 oC; ΔH= -643.20 J.g-1), and a thermal decomposition behavior in a four-steps process. The pattern diffraction presented sharp peaks at 2θ: 15.2, 25.1 and 26.0o. The Arrhenius plot obtained by isothermal thermogravimetric analysis showed a linear relation with temperature in two steps. The first step the activation energy values was Ea = 45.73 J.mol-1.K-1. The thermal degradation recovery was 3.29% after 5 days, and 11.31% against 97.4% under the dark control to photostability. Conclusion: The study contributed to characterizing the CP and the results suggest that degradation depends on the surface transition state and the ternary formed system (CP-urea-water) and that the temperature influenced this system. The data were obtained through quick and easy techniques, which use wispy raw material and presented a significant result that can be used by the entire industry in the development of new formulations.