Characterization of the porous structure of polymeric packings for HPLC

Using inverse exclusion chromatography, the porous structure of four polymeric stationary phases has been investigated. Three of the copolymers were characterized by a high degree of crosslinking because they were synthesized from two tetrafunctional monomers. The fourth copolymer was obtained from styrene (bifunctional monomer) and divinylbenzene (tetrafunctional monomer) and has a significantly smaller degree of crosslinking. To determine the pore size distribution of the copolymers, toluene, alkylphenones, phthalates, and polystyrene standards were used as probes, Additionally, changes of the volume of the copolymers when changing from water to tetrahydrofuran were determined. The results show that more stable porous structures were obtained from tetrafunctional monomers. All polymeric stationary phases have micropores in their internal structure but their contributions are different.