Water‐soluble copolymers of 1‐vinyl‐2‐pyrrolidone and acrylamide derivatives: synthesis, characterization, and metal binding capability studied by liquid‐phase polymer‐based retention technique

Hydrophilic copolymer gels were prepared by free-radical copolymerization of 1-vinyl-2-pyrrolidone (NVP) and N-hydroxymethyl acrylamide (HMAm). The ratios of both monomers and crosslinker agent (CA) were varied, and the effect of external stimuli such as pH of the swelling media and inorganic ion interaction were investigated. The gels showed a pH-responsive behavior. The interactions of inorganic ions with the hydrophilic hydrogels were determined as a function of pH, copolymer composition, and variation of the composition crosslinking degree. Additionally, a decrease of the pH of the solution caused a decrease in the equilibrium degree of swelling of the copolymer gels. The capacity to remove several metal ions such as Cu(II), Cr(III), Co(II), Zn(II), Ni(II), Cd(II), and Fe(III) in the aqueous phase was determined by using the liquid-phase polymer-based retention (LPR) technique. In addition, the copolymers and their complexes with transition metal ions were characterized by the monomer reactivity ratios by using the Kelen-Tü dö s method, elemental analysis, FTIR and 1 H-NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Based on the results of swelling and retention capacity of metal ions of poly(NVP-co-HMAm), it was concluded that the swelling and retention capacity properties of the hydrogels depends on the reaction environment's pH. This is regarded as a functional hydrogel, which could be employed as biodegradable materials for applications in agriculture chemicals and as drug delivery systems.

Section: Methodsmentioning

confidence: 99%

“…Water‐soluble polymers have also been applied to this end, and different techniques such as dialysis3, 4 and ultrafiltration5–15 have been utilized to study the interactions of metal ions with these polymers.…”

Section: Introductionmentioning

confidence: 99%

Swelling behavior and metal ion retention from aqueous solution of hydrogels based on N‐1‐vinyl‐2‐pyrrolidone and N‐hydroxymethylacrylamide

Marambio

Pizarro

Jeria‐Orell

et al. 2009

“…In the washing and enrichment methods, the metal ion retention in the cell solution is defined as where C r is the metal ion concentration in the retentate (the cell solution volume, V c , after a filtrate volume of V f has been passed) and C o is the initial metal ion concentration in the cell. The filtration factor Z , expressed in relative units, is another convenient characteristic of the process 19–23, 25 The retention depends on the polymer complex dissociation, which is generally described by a reversible reaction: In systems with inorganic ion concentrations that are relatively small with respect to the polymer concentration, only the formation of ML may be taken into account.…”

Section: Resultsmentioning

confidence: 99%

Metal ion retention using the ultrafiltration technique: Preparation, characterization of the water‐soluble poly(1‐vinyl‐2‐pyrrolidone‐co‐itaconic acid) and its metal complexes in aqueous solutions

Pizarro

Marambio

Jeria‐Orell

et al. 2008

Radical copolymerization of 1-vinyl-2-pyrrolidone with itaconic acid at different feed monomer ratios (75-25 mol %) were investigated. The copolymers were characterized by elemental analysis, Fourier transform infrared (FTIR), 1 H and 13 C NMR spectroscopy. The copolymer composition was determined from elemental analysis and found to be statistical copolymers. Additionally, viscosimetric measurements, molecular weight, and polydispersity have been determined. The metal complexation of poly(1-vinyl-2-pyrrolidone-co-itaconic acid) for the metal ions such as Cr(III), Co (II), Zn(II), Ni(II), Cu(II), Cd(II), and Fe(III) were investigated at pH 3, 5, and 7 in aqueous solution. The metal ion interaction with hydrophilic polymers was determined as a function of the pH and filtration factor. Poly(1-vinyl-2-pyrrolidone-co-itaconic acid) showed a high affinity for the metal ions at pH 5 and 7. The poly(NVP-co-IA), with a copolymer composition of 29 : 71 mol % (PVA-3), presented the highest metal ion retention values, particularly at higher pHs, at which the carboxylic acid groups are nonprotonated and could easily coordinate with the metal ions. According to the interaction pattern obtained, Cr(II), Zn(II), Pb(II), and Ni(II) formed the most stable complexes at pH 7. The thermal behaviors of the copolymer and polymer metal complex were characterized using differential scanning calorimetry (DSC) and thermogravimetry techniques under nitrogen atmosphere. The copolymers present high thermal stability and do not present glass transition in DSC curves between 25 and 5008C.

“…For the new designed polymeric structures, we wish to generate a special conformation of ligand by superficial crosslinking of maleic anhydride–dicyclopentadiene (MA‐DCPD) copolymer. The choice of MA copolymers as starting substrates is justified by the fact that they are commonly used for the synthesis of water soluble or strong wetting materials, such as thickeners in paints and coatings, industrial emulsifier and flocculating agents,18–20 and carriers of biological substances 21…”

Section: Introductionmentioning

confidence: 99%

Maleic anhydride copolymers with ability to bind metal ions. 1. polydentate amine derivatives for cr (III) ions' removal

Albu

Mocioi

Mateescu

et al. 2011

New polymeric chelate structures derived from maleic anhydride-dicyclopentadiene copolymer (MA-DCPD) were synthesized by chemical modifications with triethylenetetramine (TETA), from Riedel De HaŠn AG Seelze, Hannover. Germany. Both amide and imide forms of these new polymers have been tested in the retention process of Cr (III) ions. Experimental results referring mainly to the retention capacity and retention efficiency, for different values of the working parameters: contact procedure, batch time, concentration of chelators, and pH, are presented. The polymer structures and their metal complexes were characterized by IR spectroscopy. IR spectra proved that the metal was coordinated by nitrogen from TETA. The thermal properties of modified polymers and polychelates were also examined. Based on these experimental results and literature data, we discuss a possible binding mechanism and suggest the polychelate structures.