Controlled free radical polymerization of vinyl acetate with cobalt acetoacetonate

The polymerization of vinyl acetate with the complex catalyst of cobalt acetoacetonate [Co (acac)2] and DMF ligand with benzoyl peroxide initiator has been successfully carried out in bulk and in solution. The bulk polymerization has been used in a new route consisting of a one-step polymer formation in a fine capillary tube. In this process, the high rate of propagation was used to carry out the reaction in a microcapillary tube. Under 60°C, the colour-free reaction without solid catalyst impurity was 95% complete within a few hours. The high molecular weight of polyvinyl acetate (PVAc) with its relatively low molecular distribution without unreacted monomer provided a new method in microprocessing of the controlled radical polymerization of vinyl acetate in a one-step polymerization process. PVAc polymerization systems showed induction time, which was reduced in this reaction with using complex of DMF/ Co(acac)2. The kinetics of the reaction with a smaller degree of branching from this catalyst indicated that the electronegativity of the transition metal and diffusion of the homogeneous catalyst with DMF are important factors of fast polymerization in the bulk. Thermal properties of the polymer indicated a lower glass transition state. The easily reformed or stretched microsolid polymer demonstrated 20% crystallinity.