Free-radical polymerization of dimethyl vinylbenzylphosphonate controlled by tempo

The free radical polymerization of a phosphonated styrene, dimethyl vinylbenzylphosphonate (VBP), in the presence of stable nitroxide 2,2,6,6-tetramethyl-1-piperidinyloxyl radical (TEMPO), initiated by dicumyl peroxide (DCP) at 125 degreesC, has been studied. The apparent rate of polymerization K-p[M-.] is eight times higher than that of styrene, but the living character of the polymerization could not be verified by SEC. So, a macromolecular initiator PS-TEMPO was used in order to follow the evolution of average number molecular weights (M) over bar (n) by H-1 NMR. Under these conditions, the living character of the polymerization could be checked and various block copolymers (11000/7500;11000/11000), were prepared. As for vinylbenzyl chloride and other monomers bearing electroattractive groups, the polymerization was shown to be much faster than that of styrene.