Characterization of the porous structure of polymeric packings for HPLC

Using inverse exclusion chromatography, the porous structure of four polyme ric stationary phases has been investigated. Three of the copolymers were c haracterized 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, alkylph enones, phthalates, and polystyrene standards were used as probes, Addition ally, changes of the volume of the copolymers when changing from water to t etrahydrofuran were determined. The results show that more stable porous st ructures were obtained from tetrafunctional monomers. All polymeric station ary phases have micropores in their internal structure but their contributi ons are different.