Non-thermal microwave effects in radical polymerization of bio-based terpenoid (meth)acrylates†
Microwave-assisted polymerization represents an opportunity to develop efficient polymerization strategies for the synthesis of (bio)macromolecules with improved properties. The possibilities will increase tremendously if non-thermal microwave effects, i.e. effect of microwaves on the kinetic constants, are operative, because we can increase at the same time conversion and molecular weight. This work investigates these effects in the free radical polymerization of bio-based terpenoid (meth)acrylates finding that terpenoid acrylates present a strong non-thermal microwave effect, whereas the methacrylate ones do not show any effect. The reasons for these findings are discussed and the results compared with the apparently conflicting literature.