Acrylated soybean oil: a key intermediate for more sustainable elastomeric materials from silicones

The myriad benefits of silicone polymers can be made more sustainable by replacing much of the elastomer body with acrylated soybean oil. The crosslinked copolymers are simply made without catalysts using an aza-Michael reaction. 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.