Bahire Filiz Şenkal

Modification of crosslinked glycidyl methacrylate-based polymers for boron-specific column extraction

Abstract Terpolymers of glycidyl methacrylate (0.4 mol) with methyl methacrylate (0.5 mol) and divinyl benzene (0.1 mol) in spherical beads form have been modified with N -methyl- d -glucamine in N -methyl pyrrolidone solvent. Polymers with (2.05 mmol g −1 ) functionality have moderate swelling ability (1.81 v / v 0 ) and show excellent boron uptake ability (2.15 mmol g −1 ) for extraction of trace quantities of H 3 BO 3 from aqueous solutions. The resinous polymer with 110–210 μm size has a reasonable breakthrough capacity (0.835 mmol g −1 ) and a sharp elution profile in the column extractions. No interferences come from Ca(II), Mg(II) and Fe(III) ions (0.1 M), though slightly in the presence of these ions due to coprecipitation of borates by the metal hydroxides formed on the resin particles. The capacity of the resin and flow rate do not change even after 20 recyclings in the column extractions. The method has been shown to be promising for large-scale boron extractions from aqueous solutions.

Glycidyl methacrylate based polymer resins with diethylene triamine tetra acetic acid functions for efficient removal of Ca(II) and Mg(II)

Abstract Crosslinked terpolymer beads prepared by suspension polymerization of glycidyl methacrylate (GMA) (0.4 mol), methyl methacrylate (MMA) (0.5 mol) and divinyl benzene (DVB) (0.1 mol) mixtures have been modified through epoxy functions in two steps: (i) by treating with excess of diethylene triamine (DETA); and (ii) by subsequent reaction with potassium chloroacetate. The resulting polymer possessing diethylene triamine tetra acetic acid (DTTA) functions (with degree of functionalization DF:1.70 mmol·g −1 ) is an efficient sorbent for removal of Ca (II) and Mg (II) ions in ppm levels. Interestingly when the sodium form of the resin is used in relatively high concentrations (0.1 M) sorbed amounts will be 10–45% in excess of the theoretical capacity due to precipitation of the metal hydroxides on polymer particles beside chelation with the metal ions. Having EDTA-like chelating units, the polymer is able to absorb also heavy metal ions such as Fe (III), Zn (II), Cd (II), Pb (II), Ni (II), Cu (II), Co (II) ions. Not having hydrolysable linkages, metal-free resins can be obtained by acid treatment (4 M HCl) without loosing its activity. The resin with DTTA functions seems to be applicable in large scale water softening processes.

Aldehyde separation by polymer‐supported oligo(ethyleneimines)

Chlorosulfonated styrene (10%) divinylbenzene resin beads reacted with an excess of ethylenediamine (EDA), diethylenetriamine (DETA), and triethylenetet- ramine (TETA) to give the corresponding sulfonamides with pendant oligo(ethylenei- mines). The resulting modified resins are useful in the separation of aldehydes from hydrocarbon mixtures. Sorption of aldehydes occurs through formation of both Schiff base and five-membered (imidazoline) rings. Sorbed aldehydes can readily be stripped from the resins by treating with dilute acid solutions. Since the sulfamide bond has a reasonable stability toward acid-base hydrolysis, the loaded resins can be regenerated and recycled by simple acid-base washings, without losing their activity. In the present study, sorption and desorption kinetics of acetaldehyde, benzaldehyde, and salicylalde- hyde have been investigated under different conditions. The aldehyde sorption obeys second-order kinetics. The method presented is applicable for all aromatic aldehydes. However, in the case of aliphatic aldehydes carrying an a-hydrogen, aldol condensation products form in solution. So aliphatic aldehydes and their aldol products are sorbed together by the resins. This limits the recovery of aliphatic aldehydes. Consequently, the resins described are cost effective sorbents for the removal and recovery of aromatic aldehydes from various mixtures. q 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2857-2864, 1997

Crosslinked poly(styrenesulfonamide) with iminoacetic acid chelating groups for hard‐water treatment

SUMMARY: Chlorosulfonated polystyrene-DVB (10%) copolymer (in beads form, 720 ‐ 840lm) has been modified with triethylenetetramine (TETA) to give the corresponding polymeric sulfonamide. By treating with the potassium salt of chloroacetic acid in water, amino groups of the polymer have been carboxymethylated almost quantitatively. The resulting material with iminoacetic acid pendant groups has very efficient chelating ability for Ca(II) and Mg(II) ions in ppm levels. The chelating polymer can be regenerated ten times by acid leaching without losing its original reactivity. It is suitable for removal of calcium and magnesium ions to supply soft water.

Polystyrene sulfonic acid esters as alkylating agents: preparation of unsymmetrical secondary amines

Abstract Spherical beads (210–290 μ) of styrene-divinyl benzene (10%) copolymer have been chlorosulfonated and reacted with alcohols to give corresponding sulfonate esters. Their reactions with primary amines, i.e. propyl amine and aniline, give the corresponding secondary amines in reasonable yields (67–76%). The resulting secondary amines are obtained by a simple filtration and distillation. Regeneration of the polymeric support can readily be achieved by acidification and subsequent reaction with thionyl chloride. The present method offers an alternative procedure for the preparation of unsymmetrical secondary amines.

Removal of nitrite ions from aqueous solutions by cross-linked polymer of ethylenediamine with epichlorohydrin

We describe, for the first time, a polymeric sorbent which is specific for nitrite ions. We have demonstrated that an epoxy-amine resin obtained by suspension polycondensation of ethylenediamine with epichlorohydrin practically contains only secondary amino groups. The hydrochloride form of the resin is extremely efficient and highly selective in the removal of nitrite ions from aqueous solutions, even in very low concentrations. Nitrite binding occurs through formation of N-nitroso groups. The nitrite-loaded resin can essentially be regenerated by concentrated acid solutions, without losing its reactivity.