Synthesis and some sorptive properties of highly crosslinked cyanomethyl styrene/divinylbenzene copolymers

Three porous copolymers of cyanomethyl styrene (CMSt) and divinylbenzene (DVB), containing 50, 60 and 70 wt% of crosslinker, are synthesized by suspension polymerization method in the presence of inert diluents. Obtained polymers have various specific surface area - 310-560 m2/g, depending on the amount of the crosslinker and contain various amount of strongly polar nitrile groups. The sorptive properties of these polymers are studied using dilute (0.5 mmol) solutions of phenol and its derivatives (2-, 3- and 4-nitrophenol, 4-hydroxyphenol). It is found that the sorption of 2-nitrophenol, the sorbate which is capable of forming strong intramolecular hydrogen bonds, is only slightly dependent on the polarity of polymer surface. This sorbate, having the lowest solubility in water is also the most adsorbed one on CMSt/DVB copolymers. Sorption of phenol and 3- and 4-nitrophenol is higher on sorbents containing higher number of polar groups. The influence of polar nitrile groups on the sorption process is the most significant in the case of hydrophilic, highly water soluble sorbate such as 4-hydroxyphenol.Polymeric sorbents are characterized using elemental analysis, FTIR, and their porous structure is characterized by nitrogen adsorption at 77 K.