Scavenger and reagent resins
Scavenger and reagent resins
Considering the limitations of gel type resins, and the drawbacks of macroporous materials (slow reaction kinetics and wide variation in relative scavenging efficiencies) a wide range of DVB crosslinked solid supports with various porogen levels were investigated in a systematic manner. The ideal materials should have the following properties, high loading, fast reaction kinetics, limited swelling, ease of handling, cheapness, chemical stability and be compatible and available with a broad range of functionalities. Chloromethylpolystyrene resins (27 in total) were prepared ranging from typical gel based resins (1 - 2 % DVB) to highly crosslinked polystyrene resins (10 - 40 % DVB) with porogens (toluene and n-Heptane) at various levels. The chloromethyl polystyrene resins were prepared by suspension co-polymerisation using a 6-vessel reactor system and were converted to aminomethyl resin and quaternary ammonium chloride ion-exchange resin. Physical characteristics were investigated including loading, bead size, surface area, pore volume and pore size. Swelling studies were conducted on all the chloromethylpolystyrene resins. It was observed that as the crosslink level increased the swelling decreased but as the porogen level increased the amount of each solvent taken up increased. The chemistry of the aminomethyl and ion-exchange resins was evaluated. Reaction variables studied included kinetics and efficiency of scavenging. Results obtained reflected the composition of the basic chloromethylated polystyrene resin i.e. the crosslink level, porogen type and porogen level. Almost all of the aminomethyl and anion-exchange resins showed a marked effect of the level of the porogen on the rate of reaction. The choice of solvent was critical for a particular type of resin with solvent effects more pronounced on the ion-exchange resins. Six commercial resins were assessed, macroporous Argopore-NH;, 1 % crosslinked gel-type aminomethyl resin, Amberlite IRA-900, Amberlite IRA-958, Dowex 2 and Dowex 4. It was concluded that the reactivity of the two Amberlite resins did not compare favourably with the 20 and 40 % crosslinked resins in any of the 3 solvent systems.
University of Southampton
O'Regan, Helen Marie
7ff4b3ca-e736-470b-9f42-54b50317700a
2002
O'Regan, Helen Marie
7ff4b3ca-e736-470b-9f42-54b50317700a
O'Regan, Helen Marie
(2002)
Scavenger and reagent resins.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Considering the limitations of gel type resins, and the drawbacks of macroporous materials (slow reaction kinetics and wide variation in relative scavenging efficiencies) a wide range of DVB crosslinked solid supports with various porogen levels were investigated in a systematic manner. The ideal materials should have the following properties, high loading, fast reaction kinetics, limited swelling, ease of handling, cheapness, chemical stability and be compatible and available with a broad range of functionalities. Chloromethylpolystyrene resins (27 in total) were prepared ranging from typical gel based resins (1 - 2 % DVB) to highly crosslinked polystyrene resins (10 - 40 % DVB) with porogens (toluene and n-Heptane) at various levels. The chloromethyl polystyrene resins were prepared by suspension co-polymerisation using a 6-vessel reactor system and were converted to aminomethyl resin and quaternary ammonium chloride ion-exchange resin. Physical characteristics were investigated including loading, bead size, surface area, pore volume and pore size. Swelling studies were conducted on all the chloromethylpolystyrene resins. It was observed that as the crosslink level increased the swelling decreased but as the porogen level increased the amount of each solvent taken up increased. The chemistry of the aminomethyl and ion-exchange resins was evaluated. Reaction variables studied included kinetics and efficiency of scavenging. Results obtained reflected the composition of the basic chloromethylated polystyrene resin i.e. the crosslink level, porogen type and porogen level. Almost all of the aminomethyl and anion-exchange resins showed a marked effect of the level of the porogen on the rate of reaction. The choice of solvent was critical for a particular type of resin with solvent effects more pronounced on the ion-exchange resins. Six commercial resins were assessed, macroporous Argopore-NH;, 1 % crosslinked gel-type aminomethyl resin, Amberlite IRA-900, Amberlite IRA-958, Dowex 2 and Dowex 4. It was concluded that the reactivity of the two Amberlite resins did not compare favourably with the 20 and 40 % crosslinked resins in any of the 3 solvent systems.
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Published date: 2002
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Local EPrints ID: 464889
URI: http://eprints.soton.ac.uk/id/eprint/464889
PURE UUID: a6920d01-f550-4f4f-8800-b04e243c9f11
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Date deposited: 05 Jul 2022 00:07
Last modified: 16 Mar 2024 19:48
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Author:
Helen Marie O'Regan
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