Chelating polymer resins

Platinum-group metals (qv) form complexes with chelating polymers with various 8-mercaptoquinoline [491-33-8] derivatives (83) (see Chelating agents). Hydroxy-substituted quinolines have been incorporated in phenol—formaldehyde resins (84). Stannic chloride catalyzes the condensation of bis(chloromethyl)benzene with quinoline (85). 

Ion exchange separations may also be done in preparation for electrothermal atomisation. An interesting variant on this method is where the resin itself, containing the bonded analyte element, is subjected to direct analysis in the solid phase. In one example one litre of seawater is passed through 500 mg of chitosan (a natural chelating polymer). The resin was then homogenized and 5 mg samples of this were analysed for vanadium. Response of vanadium from the resin and from aqueous standards was shown to be the same. 

One of the best purification processes so far discovered is based on the coordination properties of synthetic chelating polymers containing functional thiol groups [1]. Typically, effluents rejected by industries where mercury electrodes are extensively used have been purified through resins prepared with a styrene/diyjnylbenzene copolymer functionalized with thiol groups [2]. 

The condensation products of F with acetone constitute interesting precursors to resins which have found applications as adhesives, corrosion-resistant coatings and floors for the chemical industry [4a, 4c, 4d]. Numerous other monomer combinations involving F have been exploited to prepare materials for different uses [4a, 4c, 4d] and recent additions to these studies include chelate polymers for the adsorption of metal ions [23], nanocomposites incorporating Fc203 [24], an investigation of the reductive electrochemical polymerization of F in acetonitrile [25] and the anticorrosion protection offered by the ensuing polymer [26]. 

Anionic and Cationic Polymerizations o Radical Polymerization Advances o Coordination Polymerizations 0 Step-Growth Polymerization Advances 0 Synthesis of Tactic Polymers o Stereoblock Copolymers o Dispersion Polymerizations o Cellulosic Graft Copolymers o Diels-Alder Polymer Forming Reactions o A New Path To Phenolic Resins o Nitrogen Heterocycle Polymerizations o Optically Active Polymers o Poly (Phenylene Sulfide) o Poly (Aryl Ethers) o (Poly (Aryl Ether Sulfones) o Epoxy and Isocyanate Resin Replacement o Azlactone Functionalized Oligomers o Epoxy Resin-Isocyanate Reactions o Chelating Polymers o Oxazoline Functionalized Polymers o Poly (Alkyl Methacrylates) o Macromers... 

Other chelating polymers related structurally to polyethylenimine and polyethyl-enimine have been derived from cyclopolymerized diallylamines. The structure and properties of these resins have been reviewed by Hodgkin. The attempted synthesis of novel linear poly(lV-alkylethylenimine)s, for metal complexation, by demethylation of ionene polymers has been described.The reaction (involving treatment with UAIH4) was successful only with ionene oligomers. 

Svec, E, Horak, D., and Kalal, J., Reactive polymers. IX. Preparation of macroporous chelate-forming resins from the copolymer glicidyl-methacrylate-ethylmethacrylate containing iminodiacetic groups, Angew. Makromol. Chem., 63, 37, 1977. 

Ion-exchange resins are categorized by the nature of functional groups attached to a polymeric matrix, by the chemistry of the particular polymer in the matrix, and by the porosity of the polymeric matrix. There are four primary types of functionaHty strong acid, weak acid, strong base, and weak base. Another type consists of less common stmctures in specialty resins such as those which have chelating characteristics. 

In contrast to the above resins, the chelating resin Amberlite IRC-718 is based upon a macroreticular matrix. It is claimed to exhibit superior physical durability and adsorption kinetics when compared to chelating resins derived from gel polymers and should also be superior for use in non-aqueous solvent systems. 

Polyisothiouronium group chelating resins mineral processing, 6,826 Polyketones metal complexes, 2, 399 Poly(L-lysine) metal complexes, 2, 764 Polymerization solid state, 1, 470 Polymers... 

The mechanism of adhesion to various substrates has not been fully explained. Brauer Stansbury (1984b) consider that bonding to composite resins occurs by the diffusion of methacrylate polymer chains into the resin. Bonding to base metals is, perhaps, by salt or chelate bridges. Here it is significant that ZOE cements do not bond, so perhaps bonding is due to the action of free EBA on the substrate. The adhesion to porcelain is surprising. Porcelain is inert so that the attachment can hardly be chemical. Also, it would be expected that if a cement adheres to porcelain then it should adhere to untreated enamel and dentine, but this is not so. 

In addition to phosphine ligands, a variety of other monodentate and chelating ligands have been introduced to functionalized polymers [1-5]. For example, cyclo-pentadiene was immobilized to Merrifield resins to obtain titanocene complexes (Fig. 42.13) [102]. The immobilization of anionic cyclopentadiene ligands represents a transition between chemisorption and the presently discussed coordinative attachment of ligands. The depicted immobilization method can also be adopted for other metallocenes. The titanocene derivatives are mostly known for their high hydrogenation and isomerization activity (see also Section 42.3.6.1) [103]. 

Matsunaga, H., Yokoyama, T., Eldridge, R.J., Bolto, B.A. 1996. Adsorption characteristics of arsenic(lll) and arsenic(V) on iron(lll)-loaded chelating resin having lysine-Na,Na-diacetic acid moiety. Reactive and Functional Polymers, 29, 167-174. 

Chanda, M., O Driscoll, K. F., Rempel, G. L., Ligand exchange sorption of arsenate and arsenite anions by chelating resins in ferric ion form I. Weak-base chieating resin Dow XFS-4195. Reactive Polym. 7,1988, 251-261. 

Egawa, H., Nonaka, T., Ikari, M., preparation of macroreticular chelating resins containing dihydroxyphosphino and/or phosphono groups and their adsorption ability for uranium. J. Appl. Polym. Sci. 29, 1984,2045-2055. 

An optically active, supported chelating diphosphine has been prepared from the Merrifield resin using reaction (15) to give a polymer-supported analog of the homogeneous diop catalysts (28, 94). 

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