Preparation method of porous polymer materials by radiation technique and its application

The radiation polymerization of hydrophilic hydroxyethyl methacrylate monom er solution at temperatures below 0 degreesC leads to the formation of a po rous structure in the polymers. The melting peak of the eutectic water-mono mer composition at the eutectic point (above -24 degreesC) could be disting ushed and a glass transition temperature was observed at -96 degreesC. The porous structure was developed after melting small ice pieces in the po lymers after polymerization. The porous structure formed above 0 degreesC c ontained discontinuous pores and that formed below 0 degreesC had continuou s pores leading to reticular structure. In a mixture of water -dioxane -mon omer, the pore diameter decreased with increasing monomer concentration. Re placing dioxane with decane led to a maximum pore diameter at 70% monomer c oncentration. The pore diameter in 70% monomer concentration using water an d dioxane was 1 similar to4 pm, maximum activity in immobilized enzyme tabl ets was observed at this diameter. The porous structure was also varied by controlling the polymerization temperature. The durability of the immobiliz ed enzyme tablets was demonstrated by the retention of high enzyme activiti es after repeated batch enzyme reactions. Copyright (C) 2001 John Wiley & S ons, Ltd.