The thermal decomposition of arbutin

Abstract

The thermal decomposition of arbutin starts at the melting at 200°C and terminates at 288°C. Non-volatile decomposition products are mainly hydroquinone(Hq), 1,6-anhydro-β-D-glucopyranose(16AGP), 1,6-anhydro-β-D-glucofuranose(16AGF) and α- and β-D-glucose. In order to elucidate the kinetics, the methods of Friedman and Ozawa are applied for the thermal decomposition of arbutin. In Friedman's method, the activation energy is 26.27 kcal mol −1, the order of reaction is 0.985 and A = 6.94 × 10 8 sec −1. In Ozawa's method, the activation energy has an initial value of 27.87 kcal mole −1, a minimum value of 26.50 kcal mole −1 and a final average value of 27.61 kcal mole −1, the order of reaction is 1, and A = 1.55 × 10 8 sec −1.