Swelling and Network Parameters of 1-Hexadecene-Co-Trimethylolpropane Distearate Monoacrylate Sorbers

Linear and crosslinked copolymers with different compositions of 1-hexadecene and trimethylolpropane distearate monoacrylate monomers were synthesized and evaluated for oil-absorbency application. Different concentrations of ethylene glycol diacrylate (EGDA) and ethylene glycol dimethacrylate (EGDMA) crosslinkers were used. The concentration of both crosslinkers was varied from 0.5% to 2%. Copolymer compositions were determined from ¹H NMR spectroscopy. Monomer reactivity ratios were calculated using Fineman-Ross and Kelen-Tudos techniques at low conversions. The oil absorbency and swelling rate constant were measured and influenced mainly by the degree of crosslinking and the hydrophobicity of copolymer units. The final equilibrium oil content, volume fraction of polymer and swelling capacity were determined at 298 K. The effective crosslinking density V_e, theoretical crosslink density V_t, the average molecular weight between the crosslinks M_c and the polymer-toluene interaction parameter χ were determined from swelling measurements. The efficiencies of EGDA and EGDMA crosslinking agents toward copolymers were determined.     

Network and thermodynamic properties of hydrogels of poly[1-(3-sulfopropyl)-2-vinyl-pyridinium-betaine]

Samples of poly[1-(3-sulfopropyl)-2-vinyl-pyridinium-betaine] (PSPV) have been synthesized to high conversion by free radical polymerization in aqueous solution of the zwitterionic monomer SPV with several concentrations of the crosslinker N,N′-methylene-bis-acrylamide (MBA). Hydrogels obtained by swelling them in water and aqueous KSCN solution were examined by gravimetric and dimensional analysis, and by compression-strain measurements. The derived effective crosslinking density ν_e was only ca. 11% of the theoretical value, indicating low efficiency of chemical crosslinking by MBA. At 298 K increasing content of MBA produces increases in the values of ν_e, elastic moduli and polymer-water interaction parameter χ. At a fixed MBA content, increasing temperature led to decreases in the values of ν_e, elastic moduli and χ, but an increase in water content of hydrogel. For swelling in aq. KSCN solution the mechanical properties are insensitive to content of salt. Experimental and theoretical analysis afforded values of the water/polymer, salt/water and salt/polymer interaction parameters. Where appropriate the findings are compared with those reported for a different zwitterionic hydrogel and a neutral non-zwitterionic hydrogel.     

Swelling behaviors of polyelectrolyte hydrogels containing sulfonate groups

Series of maleate monoester and diester monomers based on poly(ethylene glycol) monomethyl ether (MPEG) were copolymerized using the ionizable 2‐acrylamido‐2–methyl propane sulfonic acid (AMPS) via different dose rate of electron‐beam irradiation (40–150 kGy). The crosslinking of the copolymers were carried out in aqueous acidic solutions at pH 1 or in the presence of 1% N,N‐methylene bisacrylamide (MBA) as crosslinking agent. The final equilibrium water content and swelling capacities for the prepared hydrogels were determined in aqueous solutions at pH 1, 6.8, and 12 and in aqueous salt solutions at 298 K. Swelling equilibria for prepared hydrogels were determined in different molar salt solutions of NaCl, KCl, CaCl₂, Na₂SO₄, K₂SO₄, and CaSO₄. The swelling ratios of gels in pure water and in the salt solutions were found to depend on the counterion species in the increasing sequence of Ca²⁺, Na⁺ and K⁺. Copyright © 2002 John Wiley & Sons, Ltd.     

PNVCL‐PEGMA nanohydrogels with tailored transition temperature for controlled delivery of 5‐fluorouracil

Sensitive nanohydrogels were prepared via surfactant free emulsion copolymerization of N‐vinylcaprolactam and poly(ethylene glycol) methyl ether methacrylate, and either N‐vinylpyrrolidone (VP) or 2‐methacryloyloxybenzoic acid (2MBA) to adjust the transition temperature (T_tr). The crosslinker ethylene glycol dimethacrylate was used for the polymer network construction. The resulting nanohydrogel sizes are between 120 and 300 nm. ρ‐Parameter, obtained from light scattering studies, suggests that core‐sell nanogels of flexible chains were obtained. T_tr increases with increasing comonomer content (VP or 2MBA) and decreases with decreasing pH for 2MBA containing nanohydrogels. Nanohydrogels containing 15.5% of 2MBA exhibit T_tr close to 38 °C. Nanogels are able to control the release of the loaded antineoplastic drug 5‐fluorouracil. For the prepared T/pH‐sensitive nanogels, the release is slower at pH 7.4 and 37 °C than at tumor conditions: pH 6 and 40 °C. Mathematical models were applied to evaluate the kinetics of drug release; Peppas model fitted best indicating a Fickian diffusion trough a sphere. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2662–2672     

Pegylated thermally responsive block copolymer micelles and nanogels via in situ RAFT aqueous dispersion polymerization

A very straightforward approach was developed to synthesize pegylated thermoresponsive core‐shell nanoparticles in a minimum of steps, directly in water. It is based on RAFT‐controlled radical crosslinking copolymerization of N,N‐diethylacrylamide (DEAAm) and N,N′‐methylene bisacrylamide (MBA) in aqueous dispersion polymerization. Because DEAAm is water‐soluble and poly(N,N‐diethylacrylamide) (PDEAAm) exhibits a lower critical solution temperature at 32 °C, the initial medium was homogeneous, whereas the polymer formed a separate phase at the reaction temperature. The first macroRAFT agent was a surface‐active trithiocarbonate based on a hydrophilic poly(ethylene oxide) block and a hydrophobic dodecyl chain. It was further extented with N,N‐dimethylacrylamide (DMAAm) to target macroRAFT agents with increasing chain length. All macroRAFT agents provided excellent control over the aqueous dispersion homopolymerization of DEAAm. When they were used in the radical crosslinking copolymerization of DEAAm and MBA, the stability and size of the resulting gel particles were found to depend strongly on the chain length of the macroRAFT agent, on the concentrations of both the monomer and the crosslinker, and on the process (one step or two steps). The best‐suited experimental conditions to reach thermosensitive hydrogels with nanometric size and well‐defined surface properties were determined. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2373–2390, 2009     

Insulin release behavior of poly(N-isopropylacrylamide-co-N-vinyl-2-pyrrolidone) hydrogel based on modified melamine crosslinkers

Novel hydrogels based on poly(N-isopropylacrylamide-co-N-vinyl-2-pyrrolidone) (PNIPAAm/PNVP), were synthesized by solution radical polymerization using water as solvent and different weight percentage of crosslinkers ranging from 0.5 to 4%. The monomer mol ratios of NIPAAm/VP (0.9/0.1, 0.5/0.5, and 0.1/0.9) were used in all cases. N,N′-methylenebisacrylamide (MBA) and the new synthesized N,N,N-triacrylamido melamine (MAAm) were used as crosslinkers. The swelling parameters such as the swelling ratio Q, equilibrium water content (EWC), volume fraction of polymer φ_p and volume fraction at crosslinking φ_r were calculated from swelling measurements at different temperatures. The lower critical solution temperatures (LCST) of the prepared hydrogels were measured using DSC technique. The data of LCST indicated that the NIPAAm/VP crosslinked with MAAm or MBA showed reversible swelling and shrinking with temperature changes. The temperature dependence of swelling ratio and response kinetics upon heating or cooling was also investigated to understand the smart properties, i.e., temperature sensitive properties of these smart hydrogels. The in vitro release experiments were carried out at 22 and 37°C, respectively, to investigate the effect of temperature-sensitive property of these PNIPAAm/PNVP hydrogels crosslinked with MAAm and MBA crosslinkers on insulin release profiles.     

Anisotropic swelling of hydrogel nanowires based on poly(vinylpyrrolidone) fabricated by single‐particle nanofabrication technique

We report a hydrogel nanowire based on poly(vinylpyrrolidone) (PVP) and N,N'‐methylenebis(acrylamide) (MBA), which have anisotropic swelling ratio for radius and length direction. The PVP/MBA nanowires were fabricated by single particle nanofabrication technique, which is a technique for the fabrication of polymeric nanowires using the single ion event, that cause the crosslinking reaction of polymer chains within the ion tracks along the ion paths; furthermore the size (length and radius) of the nanowires was controlled by changing the film thickness and amount of MBA crosslinker. The swelling behaviors in air and water were observed using atomic force microscopy. The PVP/MBA nanowires exhibited anisotropic swelling along the length and radius in aqueous environments, because the hydrogel nanowires consisted of crosslinked networks with inhomogeneous crosslinking points, which reflected the initial energy distribution from incident an ion within the ion track. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1950–1956     

Some properties of networks produced by the Diels-Alder reaction between poly(styrene-co-furfuryl methacrylate) and bismaleimide

Poly (styrene-co-furfuryl methacrylate) networks were prepared by the Diels-Alder (D-A) reaction in solution at 25 °C between the linear copolymer and bismaleimide (BM). The resultant crosslinked polymers were swollen to equilibrium in toluene at 25 °C and swelling properties were studied by gravimetric and dimensional measurements. The swelling behaviour of these organogels depended on the composition of the copolymer and the concentration of BM used. Shear and Young’s moduli and the effective crosslinking densities (ν_e) were determined by compression (stress)-strain measurements. The theoretical crosslinking density was higher than the ν_e for all the crosslinked copolymers. An endothermic peak without T_g was observed on the DSC curve on heating the dry crosslinked polymer. On reheating a T_g at ≈98 °C was found, which is attributed to presence of linear copolymer produced by the retro D-A reaction in the first heating. The thermal stability of a crosslinked copolymer under nitrogen and air showed differences with the stability of the linear copolymer. The increase in viscosity of the solution during the D-A reaction was followed with time, for initial linear copolymers of different molecular weights. It was found that onset of gelation increased to longer reaction times the lower the molecular weight of copolymer.     

Synthesis of polymeric hydrogels containing sulfonate group

The copolymerization of n‐dodecyl poly(oxyethylene)600 maleate (DPM‐13) with 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) has been studied in the range from 25 to 90 % DPM‐13 in the feed stock. The reactivity ratio has been determined for DPM‐13/AMPS copolymer. The copolymer compositions, utilized for determining the reactivity ratio, have been determined from nitrogen content and ¹H nuclear magnetic resonance (NMR) analysis. The copolymer was characterized by IR and ¹H‐NMR. Crosslinked poly(AMPS) and DPM‐13/AMPS copolymers were prepared in water in the presence of potassium persulfate as initiator, and 1,1‐trimethylolpropane trimethacrylate (TPT) as hexafunctional crosslinker. The percentage of TPT was varied from 0.4 to 2 wt% to study the effect of TPT content on the swelling properties of the prepared polymers. Copyright © 1999 John Wiley & Sons, Ltd.     

Preparation and properties of two-component hydrogels based on 2-acrylamido-2-methylpropane sulphonic acid

Xerogels comprising 2-acrylamido-2-methylpropane sulphonic acid (AMPS) and acrylic acid as well as AMPS and acrylamide crosslinked with hexafunctional crosslinking agent have been prepared by catalytic initiation polymerization to complete conversion. Different percentages of hexafunctional crosslinker, 1,1,1-trimethylolpropane trimethacrylate, were used to prepare crosslinked copolymers having different degree of crosslink densities. The crosslinked copolymers were swollen in water to equilibrium. The volume fraction of polymer, the swelling capacity and the equilibrium water content were obtained. Low conversion polymerization was used to determine the reactivity ratios of both monomer pairs. Fourier transform spectroscopy was utilized to measure the molar ratio of copolymers constituents. © 1998 John Wiley & Sons, Ltd.     

Swelling behavior and network structure of hydrogels synthesized using controlled UV‐initiated free radical polymerization

N‐vinyl‐2‐pyrrolidone (VP) and 2‐hydroxyethyl methacrylate (HEMA) copolymeric gels have been synthesized using UV‐initiated photopolymerization to understand their characteristic behavior for development as a bioengineering material, specifically for tissue expansion. The properties of the gels have been investigated by systematic variation of the monomer feed composition and initiator and crosslinker concentrations as well as UV irradiation intensity, which was controlled by various photomasks. The swelling kinetics and network characteristics for the various hydrogels were investigated through the observation of gel swelling behavior in saline solutions and compression modulus determination of the fully swollen hydrogels. The equilibrium swelling ratio (q_e) of the gels increased as expected with increasing VP content and decreasing crosslinker concentration. However, it was found that as the amount of initiator or UV intensity increased, unexpectedly q_e also increased, which indicates a network structure with decreasing effective crosslink density (ν_e) (or increasing average molecular weight between crosslinks (M_c)). Based on this anomalous swelling behavior and thermal analysis of the gels, a molecular structure is proposed consisting of increasing number of dangling chain ends within the polymer network. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1450–1462, 2008     

Emulsion procedures for thermally reversible covalent crosslinking of polymers

Quaternization and dequaternization of tertiary amine compounds were employed to obtain thermally reversible ionene networks from aqueous colloidal polymer dispersions prepared via emulsion polymerization. Chlorine‐functionalized polymers prepared via the emulsion copolymerization of styrene (St), butylacrylate (BA), or both with chloromethylstyrene, and amino‐functionalized polymers prepared via the emulsion copolymerization of St, BA, or both with 2‐(dimethylamino)ethylacrylate or 4‐vinylpyridine, were reacted without polymer separation, with a ditertiaryamine crosslinker and a dihalide crosslinker, respectively, to obtain crosslinked polymers. Crosslinked polymers were also obtained via the reaction of a chlorine‐functionalized polymer dispersion with an amino‐functionalized polymer dispersion or via the drying of the polymer blend prepared from the two kinds of dispersions. Reactive solubility experiments, flowability investigations (by thermocompression at ca. 215 °C), IR, and ¹H NMR analyses of the obtained crosslinked polymers indicated that the generated ionene bridges dequaternized on heating and requaternized on cooling. In comparison with solution crosslinking, no organic solvent was employed, and simple procedures were required for the preparation of the thermally reversible covalent crosslinked polymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4373–4384, 2000     

Thermally reversible linking of halide-containing polymers by potassium dicyclopentadienedicarboxylate

A novel crosslinker for thermally reversible covalent (TRC) linking of halide-containing polymers is suggested. Chlorine-containing polymers such as chloromethylstyrene copolymers, chlorinated polypropylene, polyvinylchloride, chlorinated polyisoprene, and polyepichlorohydrin were crosslinked with potassium dicyclopentadienedicarboxylate (KDCPDCA). The crosslinker was prepared by reacting potassium ethoxide with dicyclopentadienedicarboxylic acid. Because of the low solubility of KDCPDCA in organic solvents, a phase transfer catalyst, benzyltrimethyl-ammonium bromide, was employed for the crosslinking reaction. The crosslinking reaction occurred at a higher rate in a polar solvent, such as dimethylformamide, than in a nonpolar one, such as toluene, and was affected by the nature of the chlorine-containing polymer. Some of the polymers crosslinked even at room temperature. The chain-extending reaction between KDCPDCA and a α,ω-dihalide compound such as α,α′-dichloro-p-xylene, 1,4-dichlorobutane, or 1,4-dibromobutane also was carried out to obtain linear oligomers. The IR spectra indicated that the crosslinking and chain-extending reactions were based on the esterification between the halide carbon bonds of the polymer and the COOK groups of KDCPDCA. The flowability at 195 °C and solubility on heating in a dichlorobenzen-maleic compound mixture of the crosslinked polymers indicated that the TRC crosslinking occurred via the reversible Diels–Alder cyclopentadiene/dicyclopentadiene conversion as long as the polymer was thermally stable and did not contain olefinic CC bonds. The TRC linking also was confirmed by the rapid decrease of the specific viscosity of the obtained linear oligomers on heating. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4390–4401, 1999     

New Bio-Based Furanic Materials Effectively Absorb Metals from Water and Exert Antimicrobial Activity

Development of sustainable bio-based materials for removal of toxic contaminants from water is a high priority goal. Novel bio-based binary and ternary copolymers with enhanced ion-exchange, adsorption and antibacterial properties were obtained by using plant biomass-derived diallyl esters of furandicarboxylic acid (FDCA) as crosslinking agents and easily available vinyl monomers. The synthesized copolymer materials showed higher sorption capacities for Ni^II, Co^II and Cu^II compared to the commercial ion-exchange resins, and they maintained their high metal adsorption capacities for over 10 cycles of regeneration. The synthesized copolymer gels containing 1–5 wt % of the crosslinker showed excellent water absorption capacities. The synthesized copolymers with 1 % crosslinker content showed swelling ratios high enough to also act as moisture absorbents. Synthesized copolymers with crosslinker content of 10 wt % performed as contact-active antibacterials by inhibiting the growth of Gram-positive (S. aureus) and Gram-negative bacteria (E. coli, K. pneumonia) in suspension tests.     

不同交联剂对甲基丙烯酸-β-羟乙酯/E-51双甲基丙烯酸酯聚合物水凝胶性能的影响

以水溶性单体甲基丙烯酸-β-羟乙酯(HEMA)与大分子交联剂E-51双甲基丙烯酸酯(E-51-DMA)(质量比HEMA/E-51-DMA=90/10)为主要原料,分别引入了5种小分子交联剂:N,N′-亚甲基双丙烯酰胺(MBA)、二乙烯基苯(DVB)、双甲基丙烯酸乙二醇酯(EDMA)、1,1,1-三(丙烯酰氧甲基)丙烷(TAP)和2,2,2-三(丙烯酰氧甲基)乙醇(TAE),采用本体聚合方法合成了5个系列的聚合物水凝胶.研究了小分子交联剂的类型及用量对水凝胶溶胀性能、杨氏模量以及有效交联密度ve和聚合物-水相互作用参数χ的影响,并比较了不同交联剂的交联效率.结果表明,随着小分子交联剂用量的增大,水凝胶平衡含水量EWC逐渐降低,聚合物体积分数2逐渐增大,反映聚合物网络结构的有效交联密度ve以及热力学参数聚合物-水相互作用参数χ值也随之增大.通过理论交联密度和有效交联密度的线性拟合,得到所选用的5种小分子交联剂在E-51-DMA10/HEMA90水凝胶体系中的交联效率,其顺序为DVB>EDMA>TAE>MBA≈TAP.     

UV‐induced crosslinking of ring opening metathesis block copolymer micelles

Statistical and amphiphilic block copolymers bearing cinnamoyl groups were prepared by ring opening metathesis polymerization (ROMP). The UV‐induced [2 + 2] cycloaddition reaction of polymer bound cinnamic acid groups was studied in polymer thin films as well as in block copolymer micelles. In both cases, exposure to UV‐light for 10 min led to a crosslinking conversion of about 60%, as determined by FT‐IR spectroscopy and UV–vis absorption measurements. Time based IR‐spectroscopy revealed a maximum conversion of 78% reached after an irradiation time of about 16 min. For micelles obtained from polymers bearing 5 mol % or more cinnamoyl groups, the crosslinking reaction proceeded smoothly, yielding in crosslinked particles which were stable in a non‐selective solvent (CHCl₃). Diameters determined by dynamic light scattering in the selective solvent (MeOH) were similar for both, non‐crosslinked and crosslinked micelles, whereas diameters of crosslinked micelles in the non‐selective solvent (CHCl₃) were significantly larger compared to MeOH samples. This strategy of direct self assembly of block‐copolymers in a selective solvent followed by “clean” crosslinking, without the need for additional crosslinking reagents or crosslinking initiators, provides a straight forward approach toward ROMP‐based polymeric nano‐particles. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2402–2413, 2008     

Multiarm star block and multiarm star mixed‐block copolymers via azide‐alkyne click reaction

The synthesis of multiarm star block (and mixed‐block) copolymers are efficiently prepared by using Cu(I) catalyzed azide‐alkyne click reaction and the arm‐first approach. α‐Silyl protected alkyne polystyrene (α‐silyl‐alkyne‐PS) was prepared by ATRP of styrene (St) and used as macroinitiator in a crosslinking reaction with divinyl benzene to successfully give multiarm star homopolymer with alkyne periphery. Linear azide end‐functionalized poly(ethylene glycol) (PEG‐N₃) and poly (tert‐butyl acrylate) (PtBA‐N₃) were simply clicked with the multiarm star polymer described earlier to form star block or mixed‐block copolymers in N,N‐dimethyl formamide at room temperature for 24 h. Obtained multiarm star block and mixed‐block copolymers were identified by using ¹H NMR, GPC, triple detection‐GPC, atomic force microscopy, and dynamic light scattering measurements. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 99–108, 2010     

Synthesis,Characterisation and Electrical Properties of Supramolecular DNA‐Templated Polymer Nanowires of 2,5‐(Bis‐2‐thienyl)‐pyrrole

Supramolecular polymer nanowires have been prepared by using DNA‐templating of 2,5‐(bis‐2‐thienyl)‐pyrrole (TPT) by oxidation with FeCl₃ in a mixed aqueous/organic solvent system. Despite the reduced capacity for strong hydrogen bonding in polyTPT compared to other systems, such as polypyrrole, the templating proceeds well. FTIR spectroscopic studies confirm that the resulting material is not a simple mixture and that the two types of polymer interact. This is indicated by shifts in bands associated with both the phosphodiester backbone and the nucleobases. XPS studies further confirm the presence of DNA and TPT, as well as dopant Cl^? ions. Molecular dynamics simulations on a [{dA₂₄:dT₂₄}/{TPT}₄] model support these findings and indicate a non‐coplanar conformation for oligoTPT over much of the trajectory. AFM studies show that the resulting nanowires typically lie in the 7–8 nm diameter range and exhibit a smooth, continuous, morphology. Studies on the electrical properties of the prepared nanowires by using a combination of scanned conductance microscopy, conductive AFM and variable temperature two‐terminal I–V measurements show, that in contrast to similar DNA/polymer systems, the conductivity is markedly reduced compared to bulk material. The temperature dependence of the conductivity shows a simple Arrhenius behaviour consistent with the hopping models developed for redox polymers.     

Hydrophilic and hydrophobic copolymer systems based on acrylic derivatives of pyrrolidone and pyrrolidine

This article deals with the synthesis of hydrophilic methacrylic monomers derived from ethyl pyrrolidone [2‐ethyl‐(2‐pyrrolidone) methacrylate (EPM)] and ethyl pyrrolidine [2‐ethyl‐(2‐pyrrolidine) methacrylate (EPyM)] and their respective homopolymers. For the determination of their reactivity in radical copolymerization reactions, both monomers were copolymerized with methyl methacrylate (MMA), the reactivity ratios being calculated by the application of linear and nonlinear mathematical methods. EPM and MMA had ratios of r_EPM = 1.11 and r_MMA = 0.76, and this indicated that EPM with MMA had a higher reactivity in radical copolymerization processes than vinyl pyrrolidone (VP; r_VP = 0.005 and r_MMA = 4.7). EPyM and MMA had reactivity ratios of r_EPyM = 1.31 and r_MMA = 0.92, and this implied, as for the EPM–MMA copolymers, a tendency to form random or Bernoullian copolymers. The glass‐transition temperatures of the prepared copolymers were determined by differential scanning calorimetry (DSC) and were found to adjust to the Fox equation. Total‐conversion copolymers were prepared, and their behavior in aqueous media was found to be dependent on the copolymer composition. The swelling kinetics of the copolymers followed water transport mechanism case II, which is the most desirable kinetic behavior for a swelling controlled‐release material. Finally, the different states of water in the hydrogels—nonfreezing water, freezing bound water, and unbound freezing water—were determined by DSC and found to be dependent on the hydrophilic and hydrophobic units of the copolymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 395–407, 2003     

Effect of chemical structure on the properties of some hydrogels prepared by using gamma radiation polymerization

Several hydrogels were prepared using radiolytic polymerization of aqueous solutions of acrylamide or acrylamide containing appropriate comonomer such as acrylic acid, maleic acid, itaconic acid, and maleic anhydride. The hydrogels have been prepared at an irradiation dose of 30 kGy. The effects of the chemical structure of the monomer(s) and crosslinking agents on the yield of homopolymer(s) or copolymers have been studied. These crosslinking agents include N, N′‐methylene dimethacrylate (MDA) and N, N′‐methylene bisallyamide (MBA). The hydrogels obtained were characterized using swelling technique, thermal and spectroscopic analysis. The results obtained showed that the prepared samples are able to reject sodium ions and are not able to recover the Basic Blue Dye from their aqueous solution. © 2005 John Wiley & Sons, Ltd.