Synthesis and superswelling behavior of carboxymethylcellulose–poly(sodium acrylate‐co‐acrylamide) hydrogel

In this paper, attention is paid to synthesis and swelling behavior of a superabsorbent hydrogel based carboxymethylcellulose (CMC) and polyacrylonitrile (PAN). The physical mixture of CMC and PAN was hydrolyzed in NaOH solution to yield hydrogel, CMC–poly(NaAA‐co‐AAm). During alkaline hydrolysis, the nitrile groups of PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups followed by in situ crosslinking of the grafted PAN chains. A proposed mechanism for hydrogel formation was suggested and the structure of the product was established using FTIR spectroscopy. The reaction variables affecting the swelling capacity of the hydrogel were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. Swelling measurements of the synthesized hydrogels in various chloride salt solutions indicated a swelling‐loss with increase in the ionic strength of the salt solutions. The pH of the various solutions also affected the swelling of the superabsorbent. Furthermore, the present hydrogels showed a pH‐reversible property. Finally, the swelling kinetics of synthesized hydrogels with various absorbent particle sizes was briefly examined. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Radiation initiated synthesis of 2‐acrylamidoglycolic acid grafted carboxymethyl cellulose as pH‐sensitive hydrogel

This article exploits a new approach for synthesis of carboxymethyl cellulose/poly 2‐acrylamidoglycolic acid by graft and crosslinked copolymerization in aqueous solution by a simple one‐step using γ‐radiation. The reaction parameters affecting the equilibrium swelling, i.e., mass ratio of AG to CMC and irradiation dose were systematically optimized to achieve a superabsorbent hydrogel with a maximum swelling capacity. The structure, crystallinity, thermal stability, and surface morphology were characterized by Fourier transform infrared spectroscopy (FT‐IR) and elemental analysis, X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), respectively. FTIR proved that the grafting reaction occurred between the hydroxyl group of CMC and PAG chain. The thermal analysis data show that the prepared hydrogel is more thermally stable than pure CMC. The swelling behaviors in distilled water in various pH solutions, temperature and various ionic salt solutions (NaCl as monovalent, CaCl₂ as divalent and FeCl₃ as trivalent) were investigated in detail. The effect of cationic salt solutions on the swelling had the following order: Na⁺ > Ca²⁺ > Fe³⁺. In addition, the pH‐reversibility was preliminarily investigated with alternating pH between 12 and 2. The equilibrium swelling of CMC/PAG was achieved in 70 min. The hydrogel was responsive to the pH and salts; it also has reversible swelling and deswelling character. POLYM. ENG. SCI., 54:2753–2761, 2014. © 2013 Society of Plastics Engineers     

Removal of heavy metals from model wastewater by using carboxymehyl cellulose/2‐acrylamido‐2‐methyl propane sulfonic acid hydrogels

A series of functional copolymer hydrogels composed of carboxymethyl cellulose (CMC) and 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) were synthesized using γ‐radiations‐induced copolymerization and crosslinking. Preparation conditions were optimized, and the swelling characteristics were investigated. The ability of the prepared hydrogels to recover some toxic metal ions from their aqueous solutions was studied. The prepared hydrogel showed a great capability to recover metal ions such as: Mn⁺², Co⁺², Cu⁺², and Fe⁺³ from their solutions. The data revealed that the chelating ability of the prepared hydrogels is mainly dependent on their internal composition, in addition to the physical properties of the metal ion solution such as pH and metal ion concentration. The data show that the chelating ability of the prepared hydrogels increases by increasing the AMPS content in the hydrogel as well as the increment in the pH of the solution and the metal ion concentration. The prepared CMC/AMPS copolymer hydrogels are chemically stable enough to be reused for at least five times with the same efficiency. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Calcium‐carboxymethyl chitosan hydrogel beads for protein drug delivery system

In this study, carboxymethyl chitosan (CMC) hydrogel beads were prepared by crosslinking with Ca²⁺. The pH‐sensitive characteristics of the beads were investigated by simulating gastrointestinal pH conditions. As a potential protein drug delivery system, the beads were loaded with a model protein (bovine serum albumin, BSA). To improve the entrapment efficiency of BSA, the beads were further coated with a chitosan/CMC polyelectrolyte complex (PEC) membrane by extruding a CMC/BSA solution into a CaCl₂/chitosan gelation medium. Finally, the release studies of BSA‐loaded beads were conducted. We found that, the maximum swelling ratios of the beads at pH 7.4 (17–21) were much higher than those at pH 1.2 (2–2.5). Higher entrapment efficiency (73.2%) was achieved in the chitosan‐coated calcium‐CMC beads, compared with that (44.4%) in the bare calcium‐CMC beads. The PEC membrane limited the BSA release, while the final disintegration of beads at pH 7.4 still leaded to a full BSA release. Therefore, the chitosan‐coated calcium‐CMC hydrogel beads with higher entrapment efficiency and proper protein release properties were a promising protein drug carrier for the site‐specific release in the intestine. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3164–3168, 2007     

Protein‐imprinted polyurethane‐grafted calcium alginate hydrogel microspheres

Protein‐imprinted polyurethane‐grafted calcium alginate hydrogel microspheres were prepared and characterized. The samples were investigated with optical microscopy, scanning electron microscopy, ¹³C‐NMR, and Fourier transform infrared spectroscopy. We proved that polyurethane side chains were successfully grafted, and this led to a relatively rough and dense surface. The samples exhibited better swelling durability when applied in specific adsorption tests. The adsorption kinetic and recognition properties indicated that the imprinted modified microspheres had excellent rebinding affinity toward the target proteins. Moreover, the influence of the preassembly pH, rebinding pH, and grafting ratio on the adsorption capacity and imprinting efficiency (IE) were systematically investigated. The study results suggest that the modified samples possessed a higher IE toward the target protein under the optimum pH and grafting ratio. Upon polyurethane grafting modification, the alginate hydrogel microspheres showed improved mechanical stability and recognition specificity. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42140.     

Water sorption behavior of CMC/PAM hydrogels prepared by γ-irradiation and release of potassium nitrate as agrochemical

Novel types of highly swelling CMC/PAM hydrogels have been prepared by grafting cross-linked polyacrylamide (PAM) chains onto carboxymethylcellulose (CMC) via a free radical polymerization method using γ-irradiation. The prepared CMC/PAM hydrogels were characterized by FT-IR spectral analysis. The AM content and irradiation dose had a direct effect on gel content of CMC/PAM hydrogels and inverse effect on their swelling ratio. The hydrogels showed enormous swelling in aqueous medium and displayed swelling characteristics which were highly dependent on the chemical composition of the hydrogel, pH and ionic strength of the medium in which the hydrogel was immersed. The results were supported by morphological properties of CMC/PAM hydrogels by using SEM. The kinetics of water uptake and the water transport mechanism were studied as a function of the CMC/AM ratio into the prepared hydrogel. The release rate of potassium nitrate entrapped within the CMC/PAM matrix increased by enhancing its loading %, and decreased with lowering AM content and irradiation dose.     

Immobilized metal ions cellophane–PGMA‐grafted membranes for affinity separation of β‐galactosidase enzyme. I. Preparation and characterization

Immobilized Cu²⁺ ions affinity cellophane–poly(glycidyl methacrylate) (PGMA)‐grafted membranes have been prepared through three steps. The first step was introducing of epoxy groups to its chemical structure through grafting process with PGMA. Factors affecting the grafting process have been studied and grafting percentage (GP) up to 233% has been obtained. The second step was converting the introduced epoxy groups to sulfonic ones. It was found that maximum amount of sulfonic groups (2.7 mmol/g) was obtained with minimum GP (46.08%). The third and last step was the immobilization of Cu²⁺ ions into sulfonated grafted membranes obtained from the previous step. Maximum amount of immobilized Cu²⁺ ions was found to be 60.9 ppm per gram of polymer. The verification of the grafting and sulfonation steps has been performed through characterization of the obtained membranes using FTIR, TGA, and EDAX analysis. Finally, Cu²⁺‐immobilized membranes have been evaluated in separation of β‐galactosidase (β‐Gal) enzyme from its mixture with bovine serum albumin (BSA) in different pH medium. Maximum protein adsorption, for both proteins, has been obtained at pH range 4–4.5; as 90 and 45% for β‐Gal and BSA, respectively. The results showed high affinity toward β‐Gal separation although BSA concentration (0.5%) is 20‐folds of β‐Gal (0.025%). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Hydrolyzed collagen‐based hydrogel with salt and pH‐responsiveness properties

A novel hydrolyzed collagen‐based hydrogel has been prepared by grafting the binary mixture of acrylamide and 2‐acrylamido‐2‐methylpropanesulfonic acid onto the collagen backbone in the presence of a crosslinking agent. Its physicochemical properties in aqueous solution were studied. The effect of reaction variables on both gel content and swelling capacity was investigated to achieve a hydrogel with improved absorbency and gel content. The absorbency under load of optimized hydrogel was also investigated by using an absorbency under load tester at various applied pressures. The swelling ratio in various salt solutions was also determined and additionally, the swelling of hydrogels was measured in solutions with pH ranged 1–13. The synthesized hydrogel exhibited a pH‐responsiveness character so that a swelling‐collapsing pulsatile behavior was recorded at pH 2 and 8. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Effect of attapulgite contents on release behaviors of a pH sensitive carboxymethyl cellulose‐g‐poly(acrylic acid)/attapulgite/sodium alginate composite hydrogel bead containing diclofenac

A series of pH‐sensitive composite hydrogel beads, carboxymethyl cellulose‐g‐poly(acrylic acid)/attapulgite/sodium alginate (CMC‐g‐PAA/APT/SA), were prepared by combining CMC‐g‐PAA/APT composite and SA, using Ca²⁺ as the ionic crosslinking agent and diclofenac sodium (DS) as the model drug. The effects of APT content and external pH on the swelling properties and release behaviors of DS from the composite hydrogel beads were investigated. The results showed that the composite hydrogel beads exhibited good pH‐sensitivity. Introducing 20% APT into CMC‐g‐PAA hydrogel could change the surface structure of the composite hydrogel beads, decrease the swelling ability, and relieve the burst release effect of DS. The drug cumulative release ratio of DS from the hydrogel beads in simulated gastric fluid was only 3.71% within 3 hour, but in simulated intestinal fluid about 50% for 3 hour, 85% for 12 hour, up to 90% after 24 hour. The obtained results indicated that the CMC‐g‐PAA/APT/SA hydrogel beads could be applied to the drug delivery system as drug carriers in the intestinal tract. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Partially hydrolyzed kappa carrageenan—polyacrylonitrile as a novel biopolymer‐based superabsorbent hydrogel: Synthesis,characterization, and swelling behaviors

In this paper, synthesis and swelling behavior of a novel superabsorbent hydrogel based on kappa carrageenan (κC) and polyacrylonitrile (PAN) was investigated. To achieve partially hydrolyzed κC‐PAN hydrogel, physical mixture of κC and PAN was hydrolyzed by NaOH solution. During alkaline hydrolysis, the nitrile groups of PAN are converted to a mixture of hydrophilic carboxamide and carboxylate groups follow by in situ crosslinking of the grafted PAN chains. The reaction variables affecting on the swelling capacity of the hydrogel were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. Under the optimized conditions concluded, super swelling hydrogel with the ability of water absorption up to 3260 g/g (water/dry hydrogel powder) has been prepared. Swelling measurements of the synthesized hydrogels was carried out in various salt solutions and solutions with different pH. The results indicate that the hydrogels have good pH sensitivity and pH‐reversible property between pH 2 and pH 8. POLYM. ENG. SCI. 46:1778–1786, 2006. © 2006 Society of Plastics Engineers.     

In vitro degradation and protein release of semi‐IPN hydrogels consisted of poly(acrylic acid‐acrylamide‐methacrylate) and amylose

The enzymatic degradation mechanism of semi‐interpenetrating network (semi‐IPN) hydrogel of poly (acrylic acid‐acrylamide‐methacrylate) crosslinked by azocompound and amylose in vitro was investigated in the presence of Fungamyl 800L (α‐amylase) and rat cecum content (cecum bacteria). The degradation mechanism involves degradable competition, i.e., reduction of azo crosslinkage is dominant in the earlier period of degradation. Subsequently, the degradation of gels is continued by combination of reduction of azo crosslinkage and hydrolysis of amylose. The cumulative release ratios of Bovine serum albumin (BSA, as a model drug) loaded semi‐IPN gels are 25% in pH 2.2 buffer solutions and 74% in pH 7.4 buffer solutions within 48 h. Moreover, the release behavior of BSA from the semi‐IPN gels indicates that it follows Fickian diffusion mechanism in pH 2.2 media and non‐Fickian diffusion and polymer chains relaxation mechanism in pH 7.4 media. The results indicate that the release of BSA from the semi‐IPN gels was controlled via a combined mechanism of pH dependent swelling and specificity to enzymatic degradation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and swelling properties of pH‐ and temperature‐sensitive interpenetrating polymer networks composed of polyacrylamide and poly(γ‐glutamic acid)

Novel hydrogels of interpenetrating polymer networks (IPNs) composed of polyacrylamide and poly(γ‐glutamic acid) were synthesized. In these systems, both polymers were crosslinked independently; this reduced the potential loss of a polymer during the washing process, as often occurs in semi‐IPN systems. Interpolymer interactions were investigated with Fourier transform infrared spectroscopy and differential scanning calorimetry. These studies suggested possible interactions between both polymers by the formation of hydrogen bonds. The swelling behavior of these hydrogels was analyzed by immersion of the hydrogel samples in deionized water at 25 and 37°C and in buffer solutions with pHs of 3, 7, and 10. The kinetics of swelling showed increases in the values of the swelling ratio with increasing immersion time in the swelling medium, molar proportion of the biopolymer in the hydrogel, temperature, and pH of the swelling medium. All of the hydrogels swelled rapidly and reached equilibrium in an average time of 40 min. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Swelling behavior and cell viability of dehydrothermally crosslinked poly(vinyl alcohol) hydrogel grafted with N‐vinyl pyrrolidone or acrylic acid using γ‐radiation

To improve equilibrium water content, dehydrothermally crosslinked poly(vinyl alcohol) (PVA) hydrogel was grafted with N‐vinyl pyrrolidone (NVP) or acrylic acid (AA) monomer using γ‐radiation. Swelling behavior of the grafted hydrogels was studied in phosphate‐buffered saline, and cell viability was evaluated using fibroblast cells from mouse connective tissue. Equilibrium water content of AA‐ and NVP‐grafted PVA hydrogel ranged between 40–60% and 60–80%, respectively, depending on radiation dose and monomer concentration. For maximum degree of swelling, the optimum monomer concentration and radiation dose were 20% by weight and 20 kGy, respectively. Fibroblast cells seeded on NVP‐grafted hydrogel had an extended oval morphology while those seeded on AA‐grafted PVA had a rounded spherical morphology. These results support the use of NVP for grafting PVA to increase swelling and improve cell viability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2862–2868, 2004     

Preparation and evaluation of composite microspheres of polyacrylamide‐grafted polysaccharides

The poor mechanical strength and instability of polysaccharide's gel takes away opportunities for versatile application. The grafting of polyacrylamide (PAM) onto polysaccharide was found to be an efficient tool for transforming its properties and obtaining stable and robust composite microspheres (CMs). In this study, free‐radical polymerization reaction was used for the grafting of PAM onto the polysaccharide backbone, and their hydrogel CMs were obtained through an ionotropic gelation method. Porous and buoyant CMs were obtained through the incorporation of sodium bicarbonate into the reaction mixture. Characterizations were done through Fourier transform infrared spectroscopy, thermal and scanning electron microscopy analysis. The mechanical strength and squeezing capacity were evaluated extensively through a modified syringe method developed in‐house. The squeezing capacity of grafted CMs diminished with the formation of a complex interpenetrating network. The Young's modulus, swelling kinetics, mechanical strength, and squeezing capacity of the grafted microspheres were compared extensively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2912–2922, 2013     

Screening and optimization through response surface methodology for synthesis of pH,temperature and salt‐sensitive Aloe vera–acrylic acid‐based biodegradable hydrogel: Its evaluation as dye adsorbent

A pH‐, temperature‐, and salt‐sensitive hydrogel was synthesized using acrylic acid (AA) as monomer, natural polysaccharide Aloe vera as backbone, ammonium persulfate–N,N‐methylene‐bis‐acrylamide as an initiator–crosslinker system via free‐radical grafting method. Different parameters such as treatment time, temperature, amount of solvent, pH, concentration of initiator, crosslinker and monomer were screened using Plackett–Burman design (PBD). The PBD showed that pH, monomer, and crosslinker were taken as the most important variables, which highly impact the swelling behavior of the synthesized hydrogel as compared to the rest of the variables. The half normality plot was used to find the significant parameters regarding the swelling capacity of the hydrogel. The center composite design was used for further optimizing the important variables like pH, monomer, and crosslinker. The pH and monomer interaction on percentage swelling (Ps) was studied through the analysis of variance model. Synthesized hydrogel Av‐cl‐poly(AA) was characterized by different techniques such as Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction, and scanning electron microscopy (SEM). The effect of different chloride salt solutions like KCl, NaCl, BaCl₂, FeCl₃, and CoCl₃·6H₂O on Ps of synthesized Av‐cl‐poly(AA)‐based hydrogel was also studied. Biodegradation studies of the synthesized polymer were also carried out using soil burial and vermicompositing methods. Biodegradation of semi interpenetrating polymer network (SIPN) was confirmed by SEM and FTIR techniques. Synthesized SIPN was also used as a device for the removal of dye and was found very effective as an adsorbent. POLYM. ENG. SCI., 59:2323–2334, 2019. © 2019 Society of Plastics Engineers     

Synthesis,Characterization, and swelling behaviors of acrylic acid/carboxymethyl cellulose superabsorbent hydrogel by glow‐discharge electrolysis plasma

This article exploits a new approach for synthesis of acrylic acid/carboxymethyl cellulose (AA/CMC) superabsorbent hydrogel in aqueous solution by a simple one‐step using glow‐discharge electrolysis plasma, in which N,N′‐methylenebisacrylamide (MBA) was used as a crosslinking agent. The reaction parameters affecting the equilibrium swelling, that is, discharge voltage, discharge time, mass ratio of AA to CMC, content of crosslinker, and degree of neutralization, were systematically optimized to achieve a superabsorbent hydrogel with a maximum equilibrium swelling. The structure, thermal stability, and morphology of AA/CMC superabsorbent hydrogel were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy. The swelling kinetics in distilled water and swelling behaviors in various pH solutions and salts solutions (NaCl, KCl, MgCl₂, CaCl₂, AlCl₃, and FeCl₃) were investigated in detail. The effect of six cationic salt solutions on the equilibrium swelling had the following order K⁺ > Na⁺ > Mg²⁺ > Ca²⁺ > Al³⁺ > Fe³⁺. In addition, the pH‐reversibility was preliminarily investigated with alternating pH between 6.5 and 2.0. The results showed that the equilibrium swelling of AA/CMC was achieved in 90 min. The hydrogel was responsive to the pH and salts, and was reversible swelling and deswelling behavior. POLYM. ENG. SCI., 54:2310–2320, 2014. © 2013 Society of Plastics Engineers     

pH‐responsive hydrogels with dispersed hydrophobic nanoparticles for the delivery of hydrophobic therapeutic agents

To investigate the delivery of hydrophobic therapeutic agents, a new class of polymer carriers was synthesized. These carriers are composed of two components: (i) a pH‐responsive hydrogel composed of methacrylic acid grafted with poly(ethylene glycol) tethers, P(MAA‐g‐EG), and (ii) hydrophobic poly(methyl methacrylate) (PMMA) nanoparticles. Before the P(MAA‐g‐EG) hydrogel was crosslinked, PMMA nanoparticles were added to the solution and upon exposure to UV light they were photoencapsulated throughout the P(MAA‐g‐EG) hydrogel structure. The pH‐responsive behavior of P(MAA‐g‐EG) is capable of triggered release of a loaded therapeutic agent, such as a low molecular weight drug or protein, when it passes from the stomach (low pH) to upper small intestine (neutral pH). The introduction of PMMA nanoparticles into the hydrogel structure affected the swelling behavior, therapeutic agent loading efficiency, and solute release profiles. In equilibrium swelling conditions the swelling ratio of nanoparticle‐containing hydrogels decreased with increasing nanoparticle content. Loading efficiencies of the model therapeutic agent fluorescein ranged from 38% to 51% and increased with increasing hydrophobic content. Release studies from neat P(MAA‐g‐EG) and the ensuing P(MAA‐g‐EG) hydrogels containing nanoparticles indicated that the transition from low pH (2.0) to neutral pH (7.0) triggered fluorescein release. Maximum fluorescein release depended on the structure and hydrophobicity of the carriers used in these studies. Copyright © 2012 Society of Chemical Industry     

Novel physical hydrogels composed of opened‐ring poly(vinyl pyrrolidone) and chitosan derivatives: Preparation and characterization

A novel, physically stabilized hydrogel system composed of chitosan (Chi) or its derivatives [e.g., carboxymethyl chitosan (CMC), sodium carboxymethyl chitosan, or trimethyl carboxymethyl chitosan (TMCMC)] with poly(vinyl pyrrolidone) (PVP) or opened‐ring poly(vinyl pyrrolidone) (OR–PVP) were prepared and characterized. TMCMC was synthesized by a novel method with dimethylsulfate as the methylation agent. The synthesized materials were characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, ¹³C‐NMR, and size exclusion chromatography. The mechanical properties, gel fraction, swelling behavior, and water state of the prepared hydrogels were investigated. Gelation occurred when the OR–PVP and Chi solutions were blended within a few seconds. However, the gelation of the OR–PVP and CMC solutions needed pH adjustment. No gelation occurred when the solutions of TMCMC and PVP or OR–PVP were blended. The quaternization or protonization of  NH₂ groups may have prevented the gelation of the solutions. The amino groups of Chi derivatives should have been free to take part in hydrophilic bonds between the two polymers. The physical entanglement of polymeric chains and strong hydrogen bonds between the polymers were considered as mechanisms for the formation of the physical hydrogels. The physical hydrogels showed ionic and pH‐sensitive swelling properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Rheological study of self‐crosslinking and co‐crosslinking of ammonium zirconium carbonate and starch in aqueous solutions

Different from common hydrogel systems formed by a polymer and a crosslinker, a hydrogel consisting of both self‐crosslinkable ammonium zirconium carbonate (AZC) and co‐crosslinkable starch was investigated in this study using rheological measurements. The evolution of viscoelastic properties of AZC solutions and AZC‐starch mixtures was characterized, and the crosslinking kinetics was determined. It was found that for both AZC self‐crosslinking and AZC‐starch co‐crosslinking, the initial bond formation rate and the gel strength exhibited a power law scaling with polymer concentrations. The competition reaction between self‐crosslinking and co‐crosslinking indicates that the gelation kinetics strongly depends on the AZC concentration but less depends on starch concentration. The temperature dependence of crosslinking was described by the Arrhenius plots which demonstrate a good linearity. It was determined that the activation energy of AZC self‐crosslinking was approximately 145–151 kJ/mol, and the activation energy of AZC‐starch co‐crosslinking was 139 kJ/mol. The effect of solution pH on the crosslinking process was also studied. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Radiation synthesis of hydrogels based on carboxymethyl cellulose and its application in removal of pollutants from wastewater

Synthesis of carboxymethyl cellulose‐g‐methacrylic acid/acrylamide Poly(CMC/MAAc:AAm) hydrogel was carried out using direct radiation copolymerization technique at ambient temperature. The gel (%) increased with increasing the content of AAm till level off at Poly(CMC/MAAc:AAm) (1/50:50 wt%) hydrogel and the swelling behavior found to be increased with increasing MAAc content in the hydrogel composition up to Poly(CMC/MAAc:AAm) (1/60:40 wt%). The grafting yield, grafting ratio, swelling behavior, and the thermal stability of Poly(CMC/MAAc:AAm) binary system are higher than those reported in our previous study by the same author which described the individual grafting of acrylamide (AAm) and methacrylic acid (MAAc) with different concentration onto carboxymethyl cellulose (CMC) using direct radiation grafting technique. The swelling kinetics and diffusion mechanism indicate that the water penetration obey non‐Fickian transport mechanism. The characterization of the prepared hydrogel was evaluated using Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The analyses by different analytical tools confirmed the successful grafting of both MAAc and AAm onto CMC. The adsorption capacity of Poly(CMC/MAAc:AAm) (1/60:40 wt%) hydrogel toward metal ions such as Cu⁺² and Co⁺², dyes such as acid blue dye and methyl green have been investigated. J. VINYL ADDIT. TECHNOL., 25:E35–E43, 2019. © 2017 Society of Plastics Engineers