Photodegradation of SF6 was performed on the surface of polyisoprene (PI) based on a brand new mechanism of "controlled release of radicals". Effective decomposition of SF6 (60% of SF6 was degraded in 4 h) was achieved due to the highly reductive radicals (mainly allylic radicals and excited C=C bond) which were generated from the photolysis of PI. No toxic fluoride was detected by FT-IR. The PI irradiated for 200 h in SF6 circumstance was examined by XPS to be doped with fluorine and sulfur. Fouling due to photoinitiated polymerization on UV lamp was avoided because the radicals were released slowly. Photolysis of SF6, in pure argon with the presence of irradiated PI showed kinetics of pseudo-first-order reaction and the degradation rate constant was 5.16 x 10(-5) s(-1). Factors which may affect the photolysis process such as introduction of O-2 and H2O were also examined. (C) 2009 Elsevier B.V. All rights reserved.