The pulsed field gradient (PFG) nuclear magnetic resonance (NMR) method has been used to study the molecular self diffusion of polystyrene (PS) solutions in porous acrylate-based monoliths It was found that the characteristic concentration and molar mass dependencies of the PS self-diffusion in the solution (describable by the Zimm and Doi-Edwards models) remain unchanged in case that the self diffusion occurred in this porous material However the self-diffusion coefficients of the PS were reduced in the monoliths by a constant factor which is independent of the molar mass and the concentration This constant factor represents the tortuosity of the porous monoliths and agrees with the reduction of the initial turnover frequency found in the ring closing metathesis reaction of diethyl diallyl malonate catalyzed in these monoliths