Immobilization of reagents and catalysts by photochemical grafting onto polymers

The possibility of immobilizing reagents and catalysts by photochemical grafting of their composites with an epoxy-diacrylate resin has been investigated. Two model systems have been examined: (i) the catalytic decomposition of aqueous sodium hypochlorite by cobalt peroxide, with oxygen production; (ii) the reaction of alkali metals with alcohols. For case (i) the catalyst was embedded, in the form of a mixture with 90% of zeolite 13X, into the photografted polymer matrix; while for case (ii) the alkali metal reagent, supported onto 90% of zeolite 13X, was incorporated into the microporous membrane. Kinetics of reaction (i) were studied in standard conditions (1.0 M NaOCl; 1.0 M NaCl; 0.25 M NaOH) between 288.2 to 318.2 K, and the relation between pseudp-first order kinetic constants and amount of catalyst incorporated into the membrane determined. Isotope effects for reaction (ii), relative to H2, D2, HD production, were measured with mixtures of deuterated and non-deuterated CH3OH(D), C2H5OH(D), n-C3H7OH(D), and i-C3H7OH(D) at 25 \ub0C, as a function of volume percent of non-deuterated alkanols in the liquid phase. For reaction (i) reactivity was found to be substantially the same in the membrane reactor as in ordinary chemical conditions: loss of catalytic activity did not exceed 15%. For reaction (ii) isotope effects, the origin of which is discussed, fully coincided with those measured in the absence of the polymer matrix