Abstract
Background: Carbamide peroxide (CP) is a hydrogen peroxide derivative bonded with urea. It is asolid 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.
[http://dx.doi.org/10.1016/j.talanta.2004.05.054] [PMID: 18969726]
[http://dx.doi.org/10.1002/prep.201600101]
[http://dx.doi.org/10.1080/00032710802507927]
[http://dx.doi.org/10.1016/0040-6031(95)02399-M]
[http://dx.doi.org/10.1016/0040-6031(93)80508-8]
[http://dx.doi.org/10.1590/S1984-82502011000400008]
[http://dx.doi.org/10.1590/S0100-40422011000700022]
[http://dx.doi.org/10.1007/s10973-009-0540-3]
[http://dx.doi.org/10.1007/s10973-013-3306-x]
[http://dx.doi.org/10.1007/s10973-015-4419-1]
[http://dx.doi.org/10.1021/ed064p180]
[http://dx.doi.org/10.5702/massspec.46.299]
[http://dx.doi.org/10.1007/s10924-012-0552-0]
[http://dx.doi.org/10.1107/S0567740881005116]
[http://dx.doi.org/10.1021/j100852a052]
[http://dx.doi.org/10.1016/j.tca.2011.03.034]
[http://dx.doi.org/10.1016/j.colsurfb.2019.04.006] [PMID: 30981068]
[http://dx.doi.org/10.1039/tf9575300344]
[http://dx.doi.org/10.1128/AAC.00751-10] [PMID: 20921319]