Methacrylic acid and methyl methacrylate oligomers adsorbed to porous isotactic poly(methyl methacrylate) ultrathin films and mechanistic studies of living template polymerization

Methacrylic acid (MAA), methyl methacrylate (MMA), methacrylamide, and oligomers of MAA and MMA were selected as a model of active radical species in living template polymerization using stereocomplex formation. The adsorption behaviors of the aforementioned model compounds were examined toward porous isotactic(it-) poly(methyl methacrylate) (PMMA) ultrathin films on a quartz crystal microbalance, which was prepared by the extracting of syndiotactic-(st-) poly(methacrylic acid) (PMAA) from it-PMMA/st-PMAA stereocomplexes. The apparent predominant adsorption of oligomers to monomers was observed in both PMAA and PMMA oligomers, suggesting that the mechanism of template polymerization follows the pick up mechanism. Although vinyl monomers were not incorporated into the porous it-PMMA ultrathin film, both PMMA and PMAA oligomers were adsorbed at the initial stages. However, adsorbed amounts were limited to about 5 and 15% at 0.1 mol L-1, respectively, which are much smaller values than corresponding st-polymers. The results imply that radical coupling reaction is prevented during template polymerization to support the resulting living polymerization. ATR-IR spectral patterns of oligomer complexes and it-PMMA slightly changed in both cases, suggesting complex formation. (c) 2008 Wiley Periodicals, Inc.