LAUSR

Abstract The photostabilies of hexanitrostillbene (HNS) were studied at 1% wt. of photostabilizers. The photostabilizers of Chiguard BP-12 (UV- 531), ADK STAB LA-326 (UV- 326), ADK STAB LA-32 (UV-P), Irganox 1010 and Everstab LS944 were used in this study. A photoreactor including a 30 W monochromatic UV lamp was used for investigation of photodegradations of solid HNS. The changes in surface area of HNS peak in HPLC chromatogram at time intervals of 2, 4, 6 and 8 h were used for calculation of kinetic rate constants of photodegradation process. The compound of UV-P photostabilizer was found to have the greatest effect on enhancing photostability for HNS among the investigated photostabilizers. The kinetic rate constants were obtained 6.2 × 10−2 and 4.1 × 10−2 h−1, respectively, for photodegradation process of HNS in absence and in presence of UV-P.