Similar nature leads to improved properties: cyclic organosilicon triperoxides as promising curing agents for liquid polysiloxanes

Abstract

Cyclic organosilicon triperoxides were found to be vinyl-selective free-radical initiators for thermal curing at 100–180 °C of vinyl-terminated polydimethylsiloxane and trimethylsilyl-terminated polymethylhydrosiloxane producing homogeneous transparent silicone rubbers with antibacterial properties. The usage of the cyclic organosilicon triperoxides as the curing agents does not require free radical inhibitors in comparison with diacyl- and dialkyl peroxides. Among the tested compounds, the peroxide with the Me–Si–Me fragment and two cyclohexane rings is a much more active curing agent (180 °C, c = 0.22 M, τ_curing = 45 min) than other organosilicon peroxides. Cured silicone samples from mixtures with vinyl-terminated polysiloxane and silicone hydride have improved mechanical properties: peroxides provide more than 200% elongation, and compression sets of the samples are less than 1%. The prepared silicone rubbers showed pronounced antibacterial activity.