Assessment of the influence of microwave irradiation on conventional and RAFT radical polymerization of styrene

Abstract

Conventional and controlled/living radical polymerization of styrene under microwave irradiation has been investigated by carefully conducted experiments with regards to temperature and microwave power conditions. Comparison with the corresponding polymerizations using oil-bath heating has revealed no significant effect of microwave irradiation on the polymerization rate under conditions where it is ensured that the temperature of the polymerization mixture is the same regardless of heating mode. The rate enhancement often seen under microwave irradiation is, at least for the monomer styrene, most likely associated with an increase in temperature caused by the microwave irradiation. This study also exposes a number of experimental parameters that should be carefully considered in regards to control of temperature and power of the microwave reactor when conducting any chemical reaction under microwave irradiation.