Catalytic oxidative polymerization of vinyl monomers using cobalt phthalocyanine complex and an exploratory investigation on the polymerization of vinyl acetate

This is the first report on the oxidative polymerization of vinyl monomers using cobalt(II) phthalocyanine pyridine {(CoPc)-Pc-II(Py)} complex. The me chanism of polymerization is described and it has been supported from the k inetic data, UV-vis, ESR and H-1 NMR studies. It is found that the rate of polymerizations (R-p) and number-average molecular weights ((M) over bar (n )) of the vinyl polyperoxides are higher for (CoPc)-Pc-II(Py) catalyzed pol ymerization compared to the usual free radical, AIBN, initiated polymerizat ion. This is supported by their activation energy of initiation (E-i) and t otal activation energy (E-a) of polymerization. The peroxide macroinitiator has been used for the polymerization of vinyl acetate. The polymerization obeys classical kinetics. The K-2 values of the peroxide macroinitiator has been determined, which reveals that it can also be used at higher temperat ure for the polymerization compared to monomeric peroxide initiator, benzoy l peroxide. The "active" poly(vinyl acetate) has also been synthesized, whi ch contains peroxy segments at the chain ends.