Microwave-accelerated RAFT polymerization of polar monomers

A monomodal microwave reactor has been employed, for the first time, for the RAFT-mediated polymerization of methyl acrylate (MA), methyl methacrylate (MMA) and styrene. At comparable temperatures, and a uniform power output of between 1 and 3 Watts, the microwave outperformed the oil bath in terms of polymerization rate for both MA and AAMA, showing rate enhancements of up to 152% and 254% for the two monomers respectively, when compared to conventional heating. Furthermore, the control appears unaffected by the rate increase, yielding low polydispersities (PDIs) (as low as 1.05) and molecular-weight values close to predicted values. Interestingly, however, the polymerization rate of styrene - a nonpolar monomer - does not seem to be enhanced by the use of microwave heating.