Synthesis and characterization of bifunctional phosphinic acid resins

Abstract

A new bifunctional polymer-supported extractant for use in metal ion recovery has been synthesized incorporating primary phosphinic acid/secondary phosphine oxide, as well as primary and secondary phosphinic acid ligands, depending on the method of synthesis. Emphasis is on polystyrene in bead form as the polymer support at various divinylbenzene cross-link levels and either with or without macroporosity. Functionalization is with PC13 and various levels of A1C13 as catalyst at temperatures ranging from -78 to +73 °C. From a study of the resin properties as a function of the synthetic variables, we make the following mechanistic conclusions: (1) under mild conditions (<0 °C), 20% substitution to primary phosphinic acid groups occurs; (2) with increasing temperature (23 °C), the extent of reaction increases to 50% with a combination of primary acid and triarylphosphine oxide groups which arise from Friedel-Crafts secondary cross-linking;(3) under forcing conditions (73 °C, high A1C13 level), 100% substitution occurs with dichlorophosphine groups followed by a disproportionation reaction giving rise to primary acid and secondary oxide groups; (4) secondary phosphine oxide groups can be further hydrolyzed to secondary phosphinic acid with strong base. Macroporosity has an influence at higher cross-link levels on both extent of functionalization and reagent accessibility: complete functionalization and reagent accessibility is maintained only with macroporous resins when more than 8% divinylbenzene is utilized for cross-linking.

Arylphosphonic Acid‐Functionalized Polyelectrolytes as Fuel Cell Membrane Material

“…Summarizing the above‐mentioned reports on polyelectrolyte properties and synthesis, phosphonic acid‐functionalized polyelectrolytes are widely recognized as attractive candidates for fuel‐cell membrane applications 4, 71–77, 82–84, 86–90, 98–100, 105. However, their availability to this date is rather limited because of synthetic problems in radical82–84 and condensation polymerization 78.…”

“…In other work groups, Lewis acid‐activated phosphorus trichloride was employed to arylphosphonate the aromatic moieties in electron‐rich polymers, such as polystyrene or PSU 86–88. However, the arylphosphonation of polystyrene was accompanied by insuppressable crosslinking because of the reactivity of aryl‐PCl 2 intermediates shown in Scheme .…”

Solid–liquid extraction of heavy rare-earths from phosphoric acid solutions using Tulsion CH-96 and T-PAR resins

“…Alexandratos et al synthesized bifunctional phosphinic acid resin by Friedel-Crafts phosphination reaction on polystyrene-divinylbenzene using AlCl 3 as catalyst [19][20][21]. It is well documented that these resins utilize both an access mechanism to bring the metal ions into polymer matrix and a recognition mechanism to selectively react with the metal ions, hence called dual-mechanism bifunctional polymers [22][23][24].…”

Effect of hydrogen‐bonding in the development of high‐affinity metal ion complexants: Polymer‐bound phosphorylated cyclodextrin

“…The suspension polymerization of vinylbenzyl chloride (VBC) and 2 wt % divinylbenzene (DVB) gave beads with a particle size of 250–325 μm 11. All chemicals, including the monomers, were purchased from the Sigma‐Aldrich or Acros Chemical Companies.…”