Influence of a Base Catalyst to the Porous Structure of Resorcinol－Formaldehyde Cryogel

Abstract

We investigated an influence of a base catalyst to form the porous structure of resorcinol－formaldehyde (RF) cryogel. The pore size depends on the number density and the growth rate of the cluster consisting of RF oligomers. To reveal the role of the base catalyst in the reaction schemes of the RF oligomer formation, the elimination reaction of a hydroxy group was extracted as the key reaction by the UV-visible absorption analysis. The quantum mechanical calculations estimated that the polymerization process was hindered by the activation barriers related to the heat of formation. Therefore, the generation rate of the oligomer was influenced by the reactivity of the elimination reaction. According to the calculation results, the differences in the heats of formation were caused by the types of cation. In comparison with the generated structures using the corresponding base catalysts, we found that pore sizes increases with heats of formaition in the elimination reaction.