Bahire Filiz Senkal

Polymer supported iminodipropylene glycol functions for removal of boron

Polymer supported iminodipropylene glycol functions have been shown to be efficient in chelation with boric acid and can be used for removal of boric acid at ppm levels. Glycidyl methacrylate (GMA)–methyl methacrylate (MMA)–DVB (divinyl benzene) terpolymer beads have been prepared and used as support. The polymer support with 3.4 mmol g−1 oxirane content can be readily modified by reacting with an excess of ethylene diamine, in high conversion yields (99.1%). Reaction of the latter with glycidol gives corresponding resin with aminopropylene glycol functions. The resulting resin has been demonstrated to be an efficient sorbent for removal of boron. The resin has 3 mmol g−1 of boron loading capacity and shows reasonably rapid sorption ability so that boron in 10 ml of H3BO3 solution (50 ppm) can be removed almost completely in less than 12 min of contact time by 0.5 g of polymer sample. Splitting of sorbed boron can be achieved by simple acid leaching (4 M HCl) and regenerated by NaOH solution (0.1 M).

Atom transfer radical graft polymerization of acrylamide from N-chlorosulfonamidated polystyrene resin, and use of the resin in selective mercury removal

Polyacrylamide was grafted from N-chlorosulfonamide groups onto crosslinked polystyrene beads using copper-mediated atom transfer radical polymerization (ATRP) methodology. A beaded polymer with a polyacrylamide surface shell was prepared in four steps, starting from styrene–divinylbenzene (10%) copolymer beads of 210–420 mm particle size: chlorosulfonation; sulfamidation with propylamine; N-chlorination with aqueous hypochloride; and grafting using a concentrated aqueous acrylamide solution with a CuBr–tetramethylethylenediamine complex (1:2). The resulting polymer resin with 84 wt% grafted polyacrylamide has been demonstrated to be an efficient mercury-specific sorbent, able to remove Hg(II) from solutions at ppm levels. No interference arises from common metal ions such as Cd(II), Fe(III), Zn(II), and Pb(II). The sorbed mercury can be eluted by repeated treatment with hot acetic acid without hydrolysis of the amide groups.  2002 Elsevier Science B.V. All rights reserved.

Poly (styrene sulfonamides) with EDTA-like chelating groups for removal of transition metal ions

Chlorosulfonated styrene–divinyl benzene (10%) resin beads (420–590 μm), when treated with an excess of triethylene tetramine (TETA), give a corresponding polymeric sulfonamide with three amine functions. The free amine functions of the resin were carboxymethylated almost quantitatively by reacting with 20% excess of potassium chloroacetate in aqueous solution. The resulting resin with iminoacetic acid functions showed rapid chelating abilities for transition metal ions such as Zn (II), Cd (II), Cu (II), Ni (II), Co (II), and Fe (III) ions. At the neutral pHs the chelating resin was able to reduce the metal ion concentrations lower than 1 ppm in about 15 min of the contacting time. Interestingly, when the resin was used in sodium form, metal binding capacities were higher than the theoretical capacity (1.66 mmol · g−1), due to simultaneous precipitation of the transition metal hydroxides on bead particles. The resin samples loaded with metal ions can be regenerated more than 10 times by simple acid-base treatments, without activity loss.

Synthesis and polymerization of N,N-diallyl morpholinium bromide

N,N-diallyl morpholinium bromide has been synthesized in high yields (96%) by stepwise condensation of morpholine with allyl chloride and allyl bromide. Polymerizability of the quaternary ammonium salt has been studied using various solvents and radical initiators such as K2S2O8 and t-butyl hydroperoxide. High yields of polymers have been obtained by precipitation polymerization in n-butanol with t-butyl hydroperoxide as radical initiator. This method gives low molecular weight polymers, whereas polymers with moderate molecular weights have been obtained in concentrated aqueous solutions. Copolymerization of the monomer with sulfur dioxide has also been studied. The structures of the monomer and polymers have been elucidated by elemental microanalysis, NMR and FT-IR spectroscopy. # 2000 Elsevier Science Ltd. All rights reserved.

Formation of composites between polyvinylimidazole and bentonites and their use for removal of remazol black B from water

ABSTRACT Poly(vinyl imidazole) (PVI)–clay (sodium bentonite and calcium bentonite) composites were designed and characterized for the removal of remazol black B (RB) that is an anionic dye water pollutant. The adsorption properties of PVI on bentonite clay particles were investigated and then PVI–clay composites were prepared at the optimum conditions for RB adsorption. X-ray diffraction (XRD) method was used for researching the intercalation behaviors of polymer–clay composites. Besides, Fourier-transform infrared spectroscopy and scanning electron microscopy analyses were carried out in order to identify the interaction mechanisms between PVI and bentonite in the composites.

Polypyrrole Dispersions on Poly(methy1 methacrylate)-blok-Poly(acrylic acid) Core-shell Latex

Poly(methyl methacrylate)-block-poly(acrylic acid) (PMMA-b-PAA) core-shell latex has been prepared by hydrolysis of poly(ethyl acrylate) block in poly(methyl methacrylate)-block-poly(ethyl acrylate) which was prepared using cupper mediated ATRP technique. Pyrrole was polymerized oxidatively on the PMMA-b-PAA core-shell latex forming polypyrrole nanoparticles. Presence of the carboxylate groups on the core-shell latex provides stable dispersions Resulting polymers were characterized by spectroscopically, electrochemically and four point-probe conductivity.

N,N′-dipropyl, N,N′-bis(4-methyl benzene sulfonyl) hydrazide: a new radical source for chain polymerization of vinyl monomers

Abstract A new radical initiator N , N ′ -dipropyl, N , N ′ -bis(4-methyl benzene sulfonyl) hydrazide (DBSH) has been prepared by condensation of N -chloro and sodium derivatives of N -propyl,4-methyl benzene sulfonamide at room temperature. As a radical initiator DBSH shows interesting properties that, although homolysis of the N – N band takes place around 52.5°C, only very low polymerization yields (∼1.0 %) are obtained below 100°C. At 100°C, bulk polymerization of methyl methacrylate proceeds rapidly and the reaction is almost quantitative in 2.5 h. This can be attributed to stability of the sulfamidyl radicals to some extent. Radical initiation efficiency of DBSH is about 0.16 and gives high molecular weight of polymers at that temperature. Presence of sulfamidyl groups in polymer chain ends have been confirmed by NMR and elementary analysis. In the study, for radical initiation ability of DBSH in bulk polymerization of methyl methacrylate and styrene monomers has been investigated in various time, temperature conditions.

Removal of Acidic and Basic Dyes from Water using Crosslinked Polystyrene Based Quaternary Ethyl Piperazine Resin

In this study, a beaded polymer with quaternary amine functions was prepared in two steps, starting from poly (vinyl benzyl chloride-ethylene glycol dimethacrylate) (PVBC) based beads, according to the synthetic protocol; modification of ethyl piperazine with PVBC (EP-PS), and quaternization of ethylpiperazine modified beads with chloroacetic acid (QEP-PS). The QEP-PS resin was used for the removal of reactive red 120 as an acidic dye and malachite green chloride as a basic dye. Dye extraction experiments were carried out simply by contacting wetted sorbent samples with aqueous dye solutions at room temperature. Capacities were determined by colorimetric analysis of the residual dye contents. The resin showed that reasonable high dye sorption capacity (0.34-0.41 g per gram of dry resin) was achieved. The adsorption conditions (initial dye concentration and pH) were varied to evaluate the mechanism of adsorption of both basic dyes and acidic dyes on the prepared resin. This material is also able to remove both the anionic dye and cationic dyes completely even from highly diluted aqueous dye solutions.

Preparation of Dicarboxylic Acid Containing Sulfonamide Based Resin and Removal of Basic Dyes

Polymer and dye interaction leading to polymer-dye complex formation exhibits many interesting and important practical features. For this purpose, dicarboxylic acid containing resin was prepared in two steps starting from poly (styrene-divinyl benzene) (PS-DVB) (10% crosslinking) based beads with a particle size of 400-590 µm, according to the synthetic protocol; chlorosulfonation, sulfamidation with iminodiacetic acid. Dye extraction experiments were carried out by contacting wetted resin samples with aqueous dye solutions at room temperature. Capacities were determined by colorimetric analysis of the residual dye content. Dye sorption capacity of the resin was found to be (0.67-0.63 g g−1 resin). This material is also able to remove the cationic dyes completely even from highly diluted aqueous dye solutions.

Preparation of the Sulfonamide Containing Block Copolymer as Polymeric Sorbent for Removal of Mercury from Aqueous Solutions

A new sulfonamide containing polymeric sorbent for the removal of mercury ions from waste waters was prepared starting from poly(glycidyl methacrylate)-b-poly(ethylene glycol)-b-poly(glycidyl methacrylate) (PGMA- b -PEG- b -PGMA) triblock copolymer prepared by using the ATRP method. Epoxy groups on the block copolymer were functionalized with amino groups. Ammonia-functionalized PGMA- b -PEG- b -PGMA was treated with excess of benzenesulfonyl chloride to obtain a sulfonamide-based polymeric sorbent. The sulfonamide containing the polymeric sorbent with a 3.5 mmol · g−1 total nitrogen content is able to selectively sorb mercury from aqueous solutions. The mercury sorption capacity of the resin is around 3.12 mmol g−1 under non-buffered conditions. Experiments performed in identical conditions with several metal ions revealed that Cd(II), Pb(II), Zn(II), Fe(III), and Fe(II) also were extractable in quantities (0–0.45 mmol/g). The sorbed mercury can be eluted by repeated treatment with 4 M HNO3 without hydrolysis of the sulfonamide groups.