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Phenolic compounds undergo radical coupling under oxidizing conditions. Silicone oils were modified with eugenol using hydrosilylation to create oils and elastomers that exhibited antioxidant activity due to the presence of phenols, as shown by DPPH and other oxidative assays. At room temperature, phenolic coupling was not observed, as judged by lack of changes in viscosity or formation of gels. By contrast, peroxide oxidants at temperatures above 90 °C led to crosslinked materials whose physical properties (related to crosslink density) correlated with eugenol content, equivalents of peroxide added and reaction time. The product elastomers were also efficient antioxidants, although there was some attenuation of activity in higher crosslinked materials, consistent with diverse radical recombination processes. [ABSTRACT FROM AUTHOR]

Silicone elastomers are widely used because of their myriad useful properties. However, their synthesis requires a high energy input. We report that the amount of silicone, per application, can be significantly reduced by the creation of silicone composites derived from soybean oil. Acrylated soybean oil, prepared by addition of acrylic acid to epoxidized soybean oil, was linked to aminoalkylsilicones using a catalyst-free aza-Michael reaction in the absence of solvents; the reaction takes <1–12 hours depending on reaction temperature (room temperature to 60 °C). The resulting opaque elastomers behave very similarly to silicone elastomers with respect to durometer, surface energy and thermal stability. Although stable to boiling water, the products readily undergo degradation by basic alcoholysis in ethanol to give processable oils. [ABSTRACT FROM AUTHOR]

Antioxidants are important mediators of radical processes. Nature exploits a variety of antioxidants, including vitamins, to moderate oxidation in living systems. Silicone oils and elastomers, widely used in personal care and biomedical applications, are rather unreactive under redox conditions and can therefore host such reactions. We report that phenolic antioxidants, including derivatives of vitamins A and E, and eugenol are readily tethered to silicone oils. These natural constituents dilute the energetic toll required to make silicones while delivering antioxidant properties to the product silicone oils. [ABSTRACT FROM AUTHOR]