No abstract

The radical polymerization of methacrylic acid (MAA) at 0, 20, 40, and 70 C was achieved in porous isotactic (it-) poly (methyl methacrylate) (PMMA) films on quartz crystal microbalance (QCM) substrates, which were prepared by layer-by-layer assembled stereocomplex films of it-PMMA and syndiotactic (st-) poly(methacrylic acid) (PMAA), followed by the subsequent extraction of st-PMAA. The MAA polymerization yields increased from 35 to 75%, as the polymerization temperature increased from 0 to 70 C. Furthermore, infrared spectroscopy revealed that a higher polymerization temperature is necessary to form it-PMMA/st-PMAA stereocomplexes via stereoregular polymerization manner that resemble native it-PMMA/st-PMAA stereocomplexes. X-ray diffraction pattern of porous it-PMMA were also investigated for reaction fields.

Macroporous silica gel was employed for layer-by-layer (LbL) film preparation of isotactic-(it-) poly(methyl methacrylate) (PMMA) and syndiotactic-(st-) poly(methacrylic acid) (PMAA). The extraction of macroporous silica gel by fluorine hydride resulted in macroporous replica particles, confirmed by SEM. The further extraction of st-PMAA from their particles gave the macroporous replica consisting of porous it-PMMA films. The obtained porous it-PMMA films as macroporous replica particles showed the re-incorporation of st-PMAA. Therefore, the structure of the porous it-PMMA film was stabilized by the macroporous particle structure, although they did not include substrate. The physically crosslinked network structures maintained the molecular porous structures, without a chemically crosslinked reaction.