Effect of binary porogen mixtures on polymer monoliths prepared by gamma-radiation initiated polymerization.

Gamma-radiation initiated polymerization is an easy-to-use and simple technique for the preparation of porous polymer monoliths widely used as active materials in separation columns. Herein, binary porogen mixtures of ethyl acetate/acetone/acetonitrile with methanol were used to synthesize diethylene glycol dimethacrylate monoliths with this technique. Systematic studies have been performed to determine the effect of the composition of the solvent mixture on the morphology and the reaction kinetics, including the growth mechanism and the growth rate. The irradiation dose-dependent conversion profiles showed that with binary solvents the polymerization is much faster than with the same compounds used as single solvents. Depending on the type and the composition of the solvent one-, two- and three-dimensional, and fractal growth mechanisms were identified.