THERMALLY MODIFIED ACRYLIC POLYMERS AS SORBENTS

Acrylic fibres were modified with ethylene diamine and pyrolysed at te mperatures up to 600 degrees C. According to IR spectroscopy, polymers pyrolysed at 300 degrees C contain nitrile and other groups which are present in the initial polymer. The specific surface area is decrease d by increasing the pyrolysis temperature. The pore size distribution reveals mainly the presence of macropores. Acrylic polymers and those pyrolysed at 300 degrees C sorb more methylene blue and alizarin yello w from aqueous solution than a non-polar commercial sorbent of high sp ecific surface area. The experimental results for dye sorption were tr eated theoretically using a diffusion-limited sorption method. The pol ymers can be ranked by the parameters of this method or their sorption ability. The dye sorption is little affected by the pores of the poly mers and is mainly affected by the interactions between the functional groups of the polymers and those of the dyes.