Unusual structure-property relations for hypercrosslinked polystyrene

UNUSUAL STRUCTURE-PROPERTY RELATIONS FOR HYPERCROSSLINKED POLYSTYRENE 

The macrosyneresis effect reduces the swelling ability of the final material in the solvent. In fact, an evident correlation between the volume of the separated solvent and the swelling capacity of the networks has always been observed in the experiments (Fig. 9.2). The extent of the macrosyneresis depends on several factors. 

It is also obvious that the macrosyneresis of the reaction media proceeds much easier from small beads of styrene—DVB copolymers than from a large-volume gel resulting from a solution of linear polystyrene their volumes usually differ by several orders of magnitude. This size factor strongly contributes to the reduced swelling capacity of the hypercrosslinked networks derived from beaded styrene—DVB copolymers (along with the inherent inner stress introduced by the DVB units in the initial fuUy swollen beaded copolymer). 

being characterized by very weak affinity to hydrophobic polystyrene, causes only a partial increase in the network volume and a partial elimination of the stresses existing in the dry material. The residual network stresses in aqueous media facilitate the absorption of all organic compounds, whether nonpolar or polar, with the sorption always accompanied by an additional volume increase of the polymer. As will be shown later, this is a supplementary driving force for absorption and a reason for the high loading capacity of hypercrosslinked adsorbing materials. 

The dimensions of the pores are pretty small, and their precise determination proved to be a real challenge. Nevertheless, relying on data 

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