ein at least one of R1 and R2 is an alkyl, cycloalkyl or aralkyl group containing up to four carbon atoms and a hydroxyl group, ether group, or carbonate group, wherein at least one of R1 and R2 is a group that includes an oxygen with a carbon adjacent thereto and an abstractable hydrogen attached to the carbon, and wherein the reactive diluent has a viscosity of less than 1000 centipoise. 2.