Kinetic Modeling of Surface-Initiated Photoiniferter-Mediated Photopolymerization in Presence of Tetraethylthiuram Disulfide
journal contributionposted on 23.12.2008, 00:00 by Santosh B. Rahane, S. Michael Kilbey, Andrew T. Metters
A rate equation-based kinetic model is developed to investigate the effect of important reaction parameters on surface-initiated photoiniferter-mediated photopolymerization (SI-PMP) of methyl methacrylate. In particular, the effect of incident light intensity and concentration of added deactivating species, tetraethylthiuram disulfide (TED), on the growth kinetics of surface-tethered poly(methyl methacrylate) (PMMA) layers was studied in detail. In accord with experimental results, model predictions suggest that maximum rates of PMMA layer growth observed during initial stages of SI-PMP increase as TED concentration ([TED]) is decreased and as light intensity is increased. Conversely, the maximum thickness of the PMMA layers, which is defined as the thickness at which 99% of the surface-tethered polymer chains are irreversibly terminated, increases as [TED] increases and as light intensity decreases. As light intensity and added deactivator affect the number of propagating surface-tethered radicals, findings from this study delineate strategies for optimizing the formation of surface-tethered PMMA brushes by SI-PMP and creating block copolymer brushes.