POLYMER SWELLING - PART-21 - STUDIES THAT CORRELATE ADSORPTIVITY WITHMOLECULAR-STRUCTURE IN CROSS-LINKED POLYSTYRENE SYSTEMS SATURATED WITH SULFUR-CONTAINING ORGANIC LIQUIDS

The adsorption parameter (alpha) for the members of five classes of su lfur-containing organic liquids were established in the usual way, and these data were compared to the results observed for the correspondin g oxyethers in order to elucidate how the mode of adsorption to the pe ndent phenyl groups of the polymer at liquid-saturation affects the re lative swelling power. The alpha-values for the thioethers are almost uniformly greater than those for the corresponding oxyethers. The alip hatic oxyethers (R'OR) adsorb unsymmetrically, i.e, the smaller, less complicated, group (R') lies close to the adsorption site while the ot her (R) extends away from that site. In contrast, only the branched or multifunctional thioethers and the higher linear aliphatic thioethers are adsorbed in this mode. The lower linear aliphatic thioethers, the non-substituted cyclic thioethers, and the disulfides are adsorbed in the symmetrical mode, i.e. both substituents attached to the sulfur a tom extend away from the adsorption site. The manner in which this cha ngeover from one mode to the other affects the alpha-values in a given homologous series is discussed. (C) 1998 Elsevier Science B.V.