Microporous poly-N,N-dimethylacrylamide-p-styrylsulfonate-methylenebis(acrylamide): a promising support for metal catalysis

The synthesis of poly-N,N-dimethylacrylamide-p-styrylsulfonate (DMAA-SS) with 4 mol% of methylene bis(acrylamide) mol% of methylene bis(acrylamide) (MBAA) as crosslinker is described. Bulk polymerization of water solution of monomers (DMAA, SS sodium salt, MBAA) was carried out under gamma irradiation. Swellability in water and various organic solvents showed mainly hydrophilic character of the resin. The ion-exchange experiments with 1 M hydrochloric acid and with [Pd(NH3)4]2+ showed very good accessibility of the inner space of the material. Polymer supported [Pd(NH34]2+ was reduced by hydrogen in methanol, sodium borohydride in water and sodium borohydride in ethanol. Under these last conditions uniform distribution of Pd throughout the resin particles was observed. The activated material turned out to be a good catalyst for the hydrogenation of p-nitrotoluene to p-toluidine in methanol under ambient conditions.