Resin ethylvinylbenzene/divinylbenzene

Divinylbenzene. This is a specialty monomer used primarily to make cross-linked polystyrene resins. Pure divinylbenzene (DVB) monomer is highly reactive polymericaHy and is impractical to produce and store. Commercial DVB monomer (76—79) is generally manufactured and suppHed as mixtures of m- and -divinylbenzenes and ethylvinylbenzenes. DVB products are designated by commercial grades in accordance with the divinylbenzene content. Physical properties of DVB-22 and DVB-55 are shown in Table 10. Typical analyses of DVB-22 and DVB-55 are shown in Table 11. Divinylbenzene [1321 -74-0] is readily polymerized to give britde insoluble polymers even at ambient temperatures. The product is heavily inhibited with TBC and sulfur to minimize polymerization and oxidation. 

The properties and performance of a commercial weak-acid resin column (Dionex CS12) have been described [41]. The substrate is a highly cross-linked, macroporous ethylvinylbenzene-divinylbenzene polymer with a bead diameter of 8 pm, a pore size of 6 nm, and a specific surface area of 3(X) m /g. In a second step, this substrate was grafted with another polymer containing carboxylate groups. The exchange capacity is listed as 2.8 mequiv/column for a 250 mm x 4 mm i.d. column. With this column, simple eluents such as hydrochloric or methanesulfonic acid can be used to separate mono- and divalent cations rapidly and efficiently under isocratic conditions. 

Different methods of solid-phase extraction (SPE) of wine volatiles were developed by using Amberlite XAD-2 polystyrenic resins (Gunata et al., 1985 Versini et al., 1988), reverse-phases Ci8 (Williams, 1982 Gianotti and Di Stefano, 1991 Di Stefano, 1991 Zulema et al., 2004 Ferreira et al., 2004), and more recently, highly cross-linked hydroxyl-ated polystyrenic phases (e.g., ENV+, Ferreira et al., 2004 Boido et al., 2003) and highly cross-linked ethylvinylbenzene-divinylbenzene copolymers (e.g., LiChrolut EN, Lopez et al., 2002 Ferreira et al., 2004 Genovese et al., 2005) stationary phases. 

Table 2 Selected columns based on the surface-aminated ethylvinylbenzene-divinylbenzene (EVB DVB) resins.

Styrene/divinylbenzene copolymers, ethylvinylbenzene/divinylbenzene copolymers, polymethacrylate, and polyvinyl alcohol resins are the most important of all the organic compounds that were tested for their suitability as substrate materials in the manufacturing process for polymer-based anion exchangers. 

Overview of Surface-Aminated Ethylvinylbenzene/Divinylbenzene Resins... 

The vinylbenzyl chloride (VBC) monomer used in this work was purchased from Aldrich (Milwaukee, WI) as an inhibited monomer mixture of the 3- and 4- isomers. The inhibitor was removed from the monomer by contact with a column of De-hibit 100 Ion Exchange Resin from Polysciences (Warrington, PA). The divinylbenzene used as a crosslinking agent was also purchased from Aldrich as an inhibited 55% solution of the isomers with 3- and 4-ethylvinylbenzene. Due to the extremely small amount of divinylbenzene used in the monomer mixtures, the inhibitor was not removed prior to polymerization. The remaining reactants and solvents include triethyl amine (99%), trimethyl phosphite (99+%), triisopropyl phosphite (95%), acetone, chloroform, and hexyl alcohol which were also purchased from Aldrich. The photoinitiator used to initiate the polymerizations was Irgacure907, donated by CibaGeigy (Hawthorne, NY). 

Meanwhile, the high-capacity lonPac ASll-HC coliunn is also available with 4 pm supermacroporous resin beads composed of ethylvinylbenzene cross-linked with 55% divinylbenzene. The highly cross-linked core of the lonPac ASll-HC-4pm column is electrostatically agglomerated with the same nanobeads as with the lonPac ASll-HC, so that the selectivity of this column is very similar to that of the lonPac ASll-HC column. However, the combination of this anion-exchange layer on the smaller particle size support material produces higher efficiency peaks and better resolution. The lonPac ASll-HC-4pm column is available in 4 mm, 2 mm, and 0.4 mm i.d. formats. The high ion-exchange capacity of this column allows the injection of more concentrated... 

Polymers Instead of being limited to styrene-divinylbenzene, polymer adsorbents are also made from polymethacrylate, divinylbenzene/ethylvinylbenzene, or vinylpyridine and are sometimes sulfonated or chloromethylated, much as are ion exchange resins. As a result, some are sufficiently hydrophilic to be used as desiccants, while others are quite hydrophobic. The effective surface area is usually smaller than for activated carbon, e.g., 5-800 mVg. Pore diameters range from about 0.3 to 200 mn. The range of application is somewhat restricted due to a higher price in comparison with other adsorbents. Currently, the main application includes removing VOCs from off-gas. 

A divinylbenzene-ethylene-styrene copolymer is sulfonated by 3.5-10% solutions of chlorosulfonic acid in organic solvents, e.g. chloroform or 1,2-dichloroethane at RT to yield cation-exchange resins. Porous st)rrene-divinyl-benzene-ethylvinylbenzene copolymers have also been treated with the reagent and hydrazine hydrate to form ion-exchange resins containing sulfonyl hydrazide groups. ... 

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