Search

Ethylene glycol dimethacrylate (EGDMA) is used as a crosslinker in poly(acrylonitrile (AN)-co-vinylbenzyl chloride (VBC)) to investigate the effect of long-chain crosslinker to the porosity of the terpolymer system. Poly(AN-co-EGDMA-co-VBC) is synthesized by using precipitation polymerization method and further hypercrosslinked by Friedel-Crafts reaction. FT-IR spectra of poly(AN-co-EGDMA-co-VBC) show that the absorption bands at ~1290 cm−1 that are assigned to the C–Cl vibrations are almost disappeared in hypercrosslinked (HXL) poly(AN-co-EGDMA-co-VBC) polymers, confirming that the hypercrosslinking reaction is successful. SEM images show that the morphologies of the polymers are retained through the hypercrosslinking reactions. Brunauer–Emmett–Teller (BET) analysis shows that hypercrosslinked polymers had a specific surface area up to 59 m2·g−1. The preliminary performance of the terpolymer adsorbent to capture polar analyte is evaluated by adsorbing salicylic acid and mefenamic acid from aqueous solution in a batch system. The maximum adsorption capacity of salicylic acid and mefenamic acid were up to 416.7 mg·g−1 and 625 mg·g−1, respectively, and the adsorption kinetic data obeyed pseudo-second-order rate equation.

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 g−1). 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.

Residues of pharmaceutical are potentially hazardous contaminants to aquatic life and human. Pharmaceutical residues have been detected in Malaysian tropical wastewaters. A challenge therein is the development of enrichment techniques able to extract polar pharmaceutical residues, since these compounds are widely found in aqueous samples yet present particular difficulties in their extraction due to their polar character. Acrylonitrile (AN)-divinylbenzene-80 (DVB-80)-vinylbenzylchloride (VBC) porous terpolymer material was prepared in the present research via precipitation polymerisation method. The porous terpolymer (MNA1) containing chlorine pendant groups was hypercrosslinked via a Friedel Crafts reaction to develop 3D network structure within the terpolymer chains. FT-IR spectrum of MNA1 showed that the chloromethyl groups derived from VBC were consumed, which was consistent with successful hypercrosslinking. The hypercrosslinked porous material was then chemically modified with ethylenediamine (EDA) (MNA2) to develop active functional groups (diamine moisties) along terpolymer chains. FT-IR spectrum showed that a new diamine absorption band appeared after the chemical modification, indicating the nitrile group was successfully converted into diamine moieties. Both experimental spectra was validated and proved by the calculated transmittance spectra. The mono-disperse spherical particles of MNA1 and MNA2 were observed using SEM analysis. Their high specific surface area and polar character (arising from AN residues), make them as potential materials to extract pharmaceutical residues.