Some factors affecting pore size in the synthesis of rigid polymer monoliths: Theory and its applicability

Abstract

AbstractMacroporous monoliths represent now widely used materials whose successful application strongly depends on their characteristics. Among those the average pore size is one of the key parameters. In this paper, we consider the applicability of theoretical calculations for the selection of appropriate porogens to generate the materials with required average pore size. A set of macroporous poly(meth)acrylate monoliths was synthesized via thermo‐ and photo‐initiated free radical polymerization and characterized in regards to their average pore size. Additionally, the difference in solubility parameters as well as Hansen's solubility parameter distance between monomers and porogens were calculated for each polymerization mixture using Hildebrand's and Hansen's solubility theories. The theoretical predications and experimental data were compared and analyzed to establish the applicability of theoretical calculations to previse average pore size for different systems. It was found that Hildebrand's theory seems to be poorly appropriate as universal tool, while Hansen's theoretical approach explained better the efficiency of solvents as porogens. The application of oligomers and polymer solutions due to the increase of viscosity as well as the variation of crosslinker amount in the monomer system can be singled out as Hansen's theory limitations at the prediction of the average pore size.