Synthesis of Cationic Polymers from Poly(acrylonitrile) and their Flocculation Effect

Abstract

Water-soluble cationic polymers were prepared by the amination of the nitrile grougs in polyacrylontrile (PAN) in the absence of catalyst at high temperature. In order to see the cationic flocculation effect of these polymers he kaolin suspension was used. The flocculation effect was studied by observing the supernatant suspension concentration in jar test, the sedimentation rate and sedimentation volume by the use of test tube. The reaction temperature, reaction time, polymer concentration and amine concentration in the amination of PAN with polyethylenepolyamine influenced greatly the flocculation effect of the cationic polymers obtained. The best flocculation effect was obtained when PAN (O.5 g) was treated with about 1-3 mol polyethylenepolyamine (to nitrile grougs) in dimethylfolmamide (40-60 ml) at 130---150°C for 3-5 hours. It was estimated by the results of IR-spectra and elemental analyses that cationic polymers obtained had primary amide, secondary amide, imidazorine ring and residual nitrile groups. Cationic polymers which were obtained by the amination with diethylentriamine, triethylenetetramine or tetraethylenepentamine under most suitable condition gave the same flocculation effect. The maximum rate of sedimentation was 7.2 cm/min, when the amount of polymers was 0.016% of kaolin.