Swelling polystyrene-divinylbenzene

A macroporous polystyrene-divinylbenzene copolymer, produced by copolymerizing a mixture of styrene and divinylbenzene, is dissolved in an organic liquid such as t-amyl alcohol or isooctane, which is a solvent for monomers. This solvent is unable to substantially swell the resulting copolymer. Macroporous cation-exchange beads are also produced from these macroporous copolymers (25,26). 

Monosized macroporous polystyrene-divinylbenzene particles have been prepared in a multistep swelling process, in which particles of different sizes... 

A typical scanning electron micrograph of the uniform macroporous polystyrene-divinylbenzene particles is given in Fig. 20. First studies on the synthesis of macroporous uniform particles were started by Ugelstad et al. [109]. They used a two-step activated swelling method to obtain macroporous uniform particles in the... 

Structure Macroporous polystyrene-divinylbenzene nonpolar adsorbent, 62-177 pm particle size Analytical Properties Used mainly in preparative-scale HPLC stable over entire pH range (1-13) sometimes difficult to achieve column-to-column reproducibility due to packing the irregular particles relatively lower efficiency than alkyl bonded phases particles tend to swell as the organic content of the mobile phase increases Reference 1... 

Polystyrene-Aluminum chloride." Aluminum chloride forms a water-stable complex with polystyrene-divinylbenzene (1.8%) copolymer denoted as (0 AICI3. In a typical preparation, the copolymer beads (59-100 mesh, 31.0 g.)are treated with carbon disulfide and then anhydrous aluminum chloride (7.5 g.). The mixture is stirred at reflux for 40 min. and then excess AICI3 is destroyed by cautious addition of water. The mixture is stirred until the original orange color fades to light yellow. The (P)-AIClj is filtered, washed with water, then successively with ether, acetone, hot iso-prnpanol, and ether, and finally dried in a vacuum oven for 18 hr. The complex is stable to the atmosphere for over one year. The anhydrous aluminum chloride can be released from the polymer by swelling with various solvents benzene, hexane, carbon disulfide. 

Whereas polymers of sufficiently high molecular weight may be soluble in the common solvents with some difficulty, network polymers do not dissolve, even at elevated temperature. They usually swell depending on the nature and cross-link density. Marcus [10] described the swelling of polystyrene cross-linked by divinylbenzene. 

Low cross-linked polystyrene resins (1% divinylbenzene) is probably the most popular solid support. These resins swell to 2-6 times their original volume depending on the solvent used. Swollen resin, after removal of solvent and without excessive drying, remains in a rubbery state and can be easily flattened for FTIR study in the transmission mode. The support-bound compound should be washed free of reagent and solvent. 

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