Polymerization of adsorbed monolayers. I. Preparation of the clay–polymer complex

Abstract

AbstractMonomolecular layers of methyl methacrylate adsorbed on the surface of sodium montmorillonite clay were prepared by saturation of the clay with the monomer, followed by desorption of the excess monomer by means of repeated washings with nonpolar hydrocarbons. No spontaneous polymerization was observed. The polymerization of these monolayers was initiated with γ‐ray irradiation or by free radical catalysts. The doses of γ‐rays and the concentration of free radical catalysts required to initiate polymerization are much higher than for the polymerization of methyl methacrylate in bulk. Complexes containing 25% MMA gave inserted polymer only; complexes containing more than 25% of MMA gave inserted and external polymer. The yields of polymerization of the inserted polymer were found to be below 50%. The inserted polymer is strongly retained by the surface of the clay. X‐ray data show that its segments are oriented horizontally (lying flat) on the surface.