Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Abstract:
Limitations often encountered in the polymer molecular weight MW and molecular weight distribution MWD has promoted research into unconvectional free radical initiators. A traditional free radical macromolecular initiator has recently been investigated for peroxide modification of the surface of disperse fillers and pigments with the objective to enabling their participation in the elementary reactions of polymerization: initiation, chain propagation and termination, resulting in the formation of an interfacial polymer layer with macromolecules grafted to the surface. Polymerization kinetics of vinyl monomers initiated by this amine-containing initiator under homophase and heterophase conditions has been examined with respect to the effect on the resulting polymer MW by means of dilatometric and viscosimetric measurements. Poly(methyl methacrylate) formed under corresponding conditions is characterized by about 2-3 times higher values of MW as compared to polystyrene. In particular, significant deceleration of the termination reactions upon interaction of growing macroradicals due to diffusion complications has been observed. High polymerization rate with the production of high-MW products resulting from the application of high-MW initiator, as compared to convectional low-MW peroxides has been attributed to the polymerization - polyrecombination mechanism of the formation of macromolecule

Keywords: Free-radical polymerization, surface-attached radicals, peroxide oligomer, molecular weight

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