ABSTRACT: Poly[acrylonitrile
(AN)-co-divinylbenzene (DVB)-co-vinylbenzyl chloride (VBC)] terpolymers were
synthesized by precipitation polymerization in the form of porous polymer
microspheres. The poly(AN-co-DVB-co-VBC) polymers were then hypercrosslinked,
via a Friedel-Crafts reaction with FeCl3 in nitrobenzene, to provide a
significant uplift in the specific surface areas of the polymers. FTIR spectra
of the hypercrosslinked poly(AN-co-DVB-co-VBC)s showed that the chloromethyl
groups derived from VBC were consumed by the Friedel-Crafts reactions, which
was consistent with successful hypercrosslinking. Hypercrosslinking installed a
number of new, small pores into the polymers, as evidenced by a dramatic
increase in the specific surface areas upon hypercrosslinking (from 530 to 1080
m2 g21 ). The hypercrosslinked polymers are very interesting for a range of
applications, not least of all for solid-phase extraction (SPE) work, where the
convenient physical form of the polymers (beaded format), their low mean
particle diameters, and narrow particle size distributions, as well as their
high specific surface areas and polar character (arising from the AN residues),
make them attractive candidates as SPE sorbents. In this regard, in a
preliminary study one of the hypercrosslinked polymers was utilized as an SPE
sorbent for the capture of the polar pharmaceutical diclofenac from a polar
environment
Keywords: diclofenac; hypercrosslinked
terpolymer; polar pharmaceuticals; polyacrylonitrile; UV absorption
