The influence of the diluent system on the porous structure formation of copolymers based on 2-vinylpyridine and divinylbenzene-diluent system: I. n-Heptane/diethylphthalate

Anion-exchange resins based on 2-vinylpyridine and divinylbenzene (DVB) were synthesized by suspension polymerization in presence of a diluent mixture of n-heptane (HEP) and diethylphthalate at different compositions. The DVB content used in the polymerization was also varied. The effects of the composition of the diluent mixture and crosslinking degree (DVB content) on the porous properties of the resins were evaluated. It was found that the development of porosity was attained whenever the content of HEP in the diluent mixture was increased for all DVB contents employed. The resins were characterized by mercury porosimetry, BET surface area determination, apparent density, swelling in methanol and visual appearance by optical microscopy.