Copolymerization Of Sodium Acrylate Research Articles

Acrylic acid -co- sodium acrylate copolymers synthetized in supercritical carbon dioxide: Is it possible to pre-neutralize polymers at high pressure?

This study focuses on the polymerization of acrylic acid together with sodium acrylate, commonly performed in traditional solvents, using supercritical carbon dioxide. This compressed polymerization solvent offers benefits like producing pure, dry polymers by a simple depressurization process. Thermally initiated free-radical polymerizations in supercritical CO2 were carried out, aiming to obtain a pre-neutralized polymer at the end of the reaction. The impact of sodium acrylate content on polymer physicochemical properties was analyzed. Conversions ranged from 86.9% to 96.7%, and sodium acrylate incorporation was verified using various analytical methods. The polymerizations displayed characteristic molar mass distributions, indicating continuous and dispersed phase polymerizations. Additionally, rheological measurements of polymer aqueous solutions revealed that viscosity increased with higher average molar mass and was responsive to pH and the presence of monovalent and divalent ions. This CO2-based approach presents a promising method for clean and safe polymer production.

Gelation of copolymers of acrylamide and sodium acrylate upon coordination with Cu2+ ions in concentrated solutions

The phase state of Cu2+ complexes with acrylamide and sodium acrylate copolymers at different copolymer concentrations and components molar ratios was studied. The change in complex stoichiometry from 2 to 3 carboxylate groups per Cu2+ ion was detected with an increase of copolymer concentration. In the concentrated solutions of copolymers, gelation is observed upon addition of Cu2+ ions, with the lowest concentration of copper required for gelation decreasing with the increase in copolymer concentration. These hydrogels are attributed to the formation of meta-stable inter-polymer metal complexes, which are able to persist due to a low segment mobility. The phase separation of complexes is shown to be associated with the bidentate coordination of carboxylate groups to Cu2+ ions, while the hydrogels formed in concentrated solutions mostly consist of bridging structures. Gelation threshold corresponds to the second critical concentration of poly(acrylamide-co-sodium acrylate) and is lower for copolymers with the higher molecular weight. Low acrylate content in the copolymers prevents collapse of the hydrogels caused by the salting-out effect. A higher gel content can be reached by increasing the copolymer concentration or the molar ratio of copper ions to carboxylate groups, with the latter reducing the swelling degree.

Porous boron nitride nanofibers enhanced sodium acrylate and acrylamide copolymer hydrogels for effective adsorption of Pb2.

A new composite hydrogel adsorbent for adsorption of Pb2+ has been prepared by combining porous boron nitride nanofibers (BNNFs) and the acrylamide and sodium acrylate copolymer (P(AANa-co-AM)) via a chemical crosslinking method. Porous BNNFs with abundant hydroxyl functional groups can form hydrogen bond interactions with carboxyl and amino functional groups of the copolymer in the composite hydrogel and carry and dissipate forces for the composite hydrogels. So the mechanical performances of the copolymer hydrogels can be effectively improved, which is very valuable for the practical application of the composite hydrogel to remove Pb2+ from waste water. The thermal stability and swelling performance of the pure copolymer hydrogels were also greatly improved. This is not only because of the strong hydrogen bond interactions but also the good thermal stability and flexibility of BNNFs. The composite hydrogel adsorbent shows superior adsorption capacity for Pb2+ (490.2 mg g-1) to most of the reported hydrogel adsorbents. The chemisorption dominates the whole adsorption process according to the pseudo-second-order kinetic and the Langmuir models. The composite hydrogel adsorbent also shows good reusability. Therefore, we believe that the prepared composite hydrogels will play an important role in removing Pb2+ from wastewater.

Discussions on the Properties of Emulsion Prepared by Using an Amphoteric Chitosan as an Emulsifier

A typical emulsion contains oil and water phases, and these two phases can be combined by an emulsifier with both lipophilic and hydrophilic groups to form a mixture. If the component of water is more than oil, the mixture is termed as o/w emulsion. The water is called the continuous phase and the oil is called the dispersed phase. Oppositely, if the component of oil is more than water, the mixture is termed as w/o emulsion. The oil is called the continuous phase and the water is called the dispersed phase. Chitosan, which is biocompatible and non-toxic, was modified as an amphoteric emulsifier to replace sodium acrylates copolymer in the preparation of emulsions. Both sodium acrylates copolymer and the modified chitosan were used as emulsifiers, respectively, and the properties of moisturizing, transmittance, the number of bacteria, and emulsion stability were measured. The experimental results showed that the amount of amphoteric chitosan is less than that of sodium acrylate copolymer by 20% under a similar degree of emulsification. The measurement of spatial moisture showed the difference in equilibrium humidity was in the range of 2.05 to 2.20 gH2O/kg dry air, indicating that the moisture retention of the modified chitosan is better. In addition, the calculation of bacterial growth confirmed that the number of bacteria in the amphoteric chitosan emulsion and the sodium acrylate copolymer emulsion were 80 and 560, respectively. The emulsion stability was tested by the separation of oil and water phases in the diluted emulsion and by centrifugal accelerated sedimentation. The results showed that, for both emulsifiers, no separation of the oil and water phases occurred within one hour, and the stability of the modified chitosan emulsion was better. Therefore, the modified chitosan successfully substitutes sodium acrylates copolymer as an emulsifier in the preparation of emulsion.

NMR spectroscopy of Cu(II) complexes with acrylamide and sodium acrylate copolymer and ω-amino acids

Macromolecular complexes of acrylamide and sodium acrylate copolymer with microelements, including Cu(II), may form at preparation of crop protection and stimulation compositions, where the copolymer serves as an adhesive, water-retaining and film-forming agent. Preparations for crop production may also contain amino acids that protect plants under stressful conditions (cold, dry, etc.). Carboxylic groups of copolymer, carboxylic and amino groups of amino acids may be involved in mixed Cu(II) ions complexes formation. Number of methylene groups separating carboxylic and amino group of amino acids affects its ability to form a stable chelate cycle and, therefore, ligand composition of mixed Cu(II) ions complexes with acrylamide and sodium acrylate copolymer and amino acid. This work is aimed at determining the ligand composition of mixed macromolecular Cu(II) ion complexes with acrylamide and sodium acrylate copolymer and ω-amino acids (β-alanine, γ-aminobutyric acid, ε-aminocaproic acid). 13C and 1H NMR spectroscopy was used to clarify complexes composition. A complex where carboxylic groups of amino acids are ligands has been found to form in aqueous solutions of Cu(II) ions and ω-amino acid (β-alanine, γ-aminobutyric acid, ε-aminocaproic acid) at molar ratio of Cu(II) ions – amino acid equal to 1 : 6. A chelate complex where both carboxylic and amino groups of β-alanine are involved in coordination has been discovered to form in the solution containing Cu(II) ions, β-alanine, as well as acrylamide and sodium acrylate copolymer at molar ratio of Cu(II) – β-alanine – copolymer COO− equal to 1 : 6 : 30. Carboxylic groups of copolymer participate in complex formation as well. Carboxylic groups of both amino acids and the copolymer have been shown to participate in complex formation in aqueous solutions containing Cu(II) ions, either γ-aminobutyric or ε-aminokaproic acid and also acrylamide and sodium acrylate copolymer.

Swelling behavior of acrylamide and sodium acrylate copolymer hydrogel in aqueous solutions of copper (II) chloride with amino acids additives

Swelling of acrylamide and sodium acrylate copolymer polyelectrolyte hydrogel in aqueous Cu(II) chloride solutions with additives of proteinogenic amino acids glycine and L-histidine has been studied. Research relevance is due to the application of such systems in agrochemical products that are supposed to have high water absorption capacity in the presence of microelements ions and amino acids, which are used to prevent nutritional deficiency and make plants resistant to adverse weather conditions and diseases. Gravimetry, atomic absorption spectrometry, FTIR ATR spectroscopy and molecular absorption spectrophotometry were used. The impact of acidity (pH 3, 5 and 7) of aqueous Cu(II) chloride solutions with amino acids additives on the hydrogel swelling degree and Cu(II) ions absorption has been determined. The reasons for changes in the hydrogel swelling degree in aqueous Cu(II) chloride solutions in presence of glycine and L-histidine have been found. The main product of the crosslinked copolymer interaction with the components of 0.01 M aqueous Cu(II) chloride solution with the addition of 0.04 M glycine or L-histidine at pH 3 has been assumed to be a mixed Cu(II) ions complex with functional groups of both copolymer and amino acids.

Synthesis, and antimicrobial and anticancer activities of sodium acrylate copolymers

This study was designed to synthesize poly(sodium acrylate-co-N-isopropylacrylamide) via aqueous free-radical polymerization using the 2,2′-azobisisobutyronitrile initiator system at 60°C. The structural characterization of the copolymer was determined by Fourier-transform infrared spectroscopy. The polymer was synthesized in two different ratios, namely, poly(NaAc-co-NIPA1:1) and poly(NaAc-co-NIPA2:1), to investigate whether it affects their antibacterial–antifungal activities and anti-tumour effects. When the antimicrobial activities of different proportions of the copolymer extracts prepared with pure water were examined using the agar disc diffusion sensitivity test (at 120 μL: 10.8 mg/µL), it was observed that they had effect at increasing rates against all the bacteria, yeasts and dermatophyte fungi such as Staphylococcus aureus COWAN 1, Staphylococcus cohnii ATCC 29974, Bacillus megaterium DSM 32, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Klebsiella pneumoniae FMC 5, Pseudomonas aeruginosa DMS 50071 SCOTTA, Candida albicans FMC 17, Candida glabrata ATCC 66032, Trichophyton sp. and Epidermophyton sp. The results of this study revealed that the obtained copolymers have significant effects on the treatment of diseases. In addition, the anti-tumour activities of the poly(NaAc-co-NIPA1:1) copolymer on human breast (MCF-7) and ovarian cancer (A-2780) cell line were specified and it was determined that high doses of the copolymer showed anti-tumour effects on both types of cancer cell lines. Also, this article reviews its antimicrobial and anticancer activities that will be of help for future scientists.

Structural and functional characterization of rice starch-based superabsorbent polymer materials

The aim of this work was to develop new, rice starch-based superabsorbent materials (SPAMs), degradable and eco-friendly. Indica rice starch-based SPAM had the best water absorption capacity (439 g water/g) with a relatively high amylose content (23.6%) that may enhance the interaction and structural strength of polymer chains through the formation of hydrogen-bond. Meanwhile, the rigidity and structure of branched chain of amylopectin can improve the water holding capacity, thus the glutinous rice starch (75.1% amylopectin content)-based SPAM also had good water absorption characteristics (399 g water/g). Regeneration rate has a certain correlation with water absorption rate, therefore, the indica rice starch-based SPAMs only lost 30% of their reswelling capacity when reused three consecutive times. On the other hand, the effects of 4 cations on SPAM water absorption were according the following order: K+ < Na+ < Ca2+ < Al3+. The formation of graft copolymer of sodium acrylate and rice starch was confirmed by Fourier Transform Infra-Red spectroscopy and X-Ray diffraction. The microstructure of SPAM showed a porous arrangement as observed by scanning electron microscopy. Finally, when present within the storage environment, the indica rice starch-based SPAM was effective in preventing rice grain moisture accumulation.

Synthesis, Characterization, and Aqueous Properties of an Amphiphilic Terpolymer with a Novel Nonionic Surfmer

A series of surfactive amphiphilic polymer PAADs were prepared from the copolymerization of sodium acrylate, dodecyl polyoxyethylene acrylate (DPA, a surfmer), and acrylamide under the action of a mixed initiating agent consisting of ammonium persulfate-sodium bisulfite/2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride. The aggregative behaviors of PAADs were explored by 13C nuclear magnetic resonance, a viscometer, and a surface tension instrument. It was found that the apparent viscosity and surface activity of PAADs were significantly improved by the increase of average sequence length of hydrophobic micro blocks, strong intermolecular hydrophobic association, or the formation of mixed micelles between hydrophobic micro blocks and micromolecular surface-active agent. The introduction of long-chain alkyls on molecular chains prolonged the average sequence length of hydrophobic micro blocks in molecular chains and enhanced the hydrophobic association between molecular chains and the tight arrangement of molecular chains on water surfaces, thereby increasing the surface activity. Moreover, the anionic monomer sodium acrylate on molecular chains, via electrostatic repulsion, promoted the conversion from intrachain association to intermolecular association and thereby facilitated the formation of dense interfacial films, enhancing the surface activity of water solutions. Then, the anion surfmer sodium dodecylbenzenesulfonate interacted with the hydrophobic micro blocks on the molecular chains to form mixed micelles, which accelerated the interchain association and enhanced the polymer surface activity. The novel polymeric micelle with higher viscosifying ability and surface activity was expected to be a promising oil drive agent for tertiary oil recovery.

Atomistic dynamics simulation to solve conformation of model PCE superplasticisers in water and cement pore solution

The working mechanism of polycarboxylate ether (PCE) type superplasticisers in concrete was studied from the point of view of conformational changes of the polymer simulated by molecular dynamics in pure water and cement pore solution. Three typical types of PCEs, namely a methoxy polyethyleneglycol monomethacrylate–sodium methacrylate copolymer (PCEM), a polyethyleneglycol mono allyl ether–sodium maleate copolymer (PCEA) and a polyethyleneglycol mono (3-methyl-3-butenyl) ether–sodium acrylate copolymer (PCEI) were investigated using large-scale atomistic molecular dynamics simulations. It was observed that the PCE polymers which possess negatively charged backbones were stretched in water due to electrostatic repulsion. However, they were found to be significantly shrunken and distorted in synthetic cement pore solution, depending on the polyethylene glycol (PEG) density along the backbone, resulting in the aggregation of PEG side chains due to the salting-out effect.

Superabsorbent nanocomposite based on methyl acrylic acid-modified bentonite and sodium polyacrylate: Fabrication, structure and water uptake

The present study demonstrates a feasible synthetic route to prepare a methyl acrylic acid-modified bentonite (MAABT)/sodium polyacrylate (SPA) superabsorbent nanocomposite, in which the MAABT serves as a reinforcing agent for SPA, as well as a cross-linking joint to enhance the network of the nanocomposite. The interfacial compatibilization effect of the MAABT was understood by copolymerization of sodium acrylate and methyl acrylate groups which were chemically bonded on the surface of bentonite. With the fine dispersion of MAABT and strong interfacial interaction, the MAABT/SPA nanocomposite achieved a water absorbency that was as high as 1287g/g under accurate controls. Additionally, it comes out that the thermal stability and water retention capacity of the nanocomposites were also improved with the incorporation of MAABT. The suggested method for reactive compatibilization of MAABT and SPA may offer routes to the design of new organic–inorganic nanocomposites for various applications.

Phase state of aqueous solutions of acrylamide–sodium acrylate copolymers in the presence of copper, zinc, and manganese ions

Introduction of copper(II), zinc(II), and manganese(II) ions into aqueous solutions of acrylamide–sodium acrylate copolymer leads to phase separation. The position of the boundary between the liquid phase and the precipitate is determined by the copolymer composition, its concentration in solution, and nature and concentration of the ion being introduced.

Quantitative characterization by asymmetrical flow field-flow fractionation of IgG thermal aggregation with and without polymer protective agents.

Complexes formed between poly(acrylates) and polyclonal immunoglobulin G (IgG) in its native conformation and after heat stress were characterized using asymmetric flow field-flow fractionation (AF4) coupled with on-line UV-Vis spectroscopy and multi-angle light-scattering detection (MALS). Mixtures of IgG and poly(acrylates) of increasing structural complexity, sodium poly(acrylate) (PAA), a sodium poly(acrylate) bearing at random 3 mol % n-octadecyl groups, and a random copolymer of sodium acrylate (35 mol%), N-n-octylacrylamide (25 mol%) and N-isopropylacrylamide (40 mol%), were fractionated in a sodium phosphate buffer (0.02 M, pH 6.8) in the presence, or not, of 0.1 M NaCl. The AF4 protocol developed allowed the fractionation of solutions containing free poly(acrylates), native IgG monomer and dimer, poly(acrylates)/IgG complexes made up of one IgG molecule and a few polymer chains, and/or larger poly(acrylates)/IgG aggregates. The molar mass and recovery of the soluble analytes were obtained for mixed solutions of poly(acrylates) and native IgG and for the same solutions incubated at 65 °C for 10 min. From the combined AF4 results, we concluded that in solutions of low ionic strength, the presence of PAA increased the recovery ratio of IgG after thermal stress because of the formation of electrostatically-driven PAA/IgG complexes, but PAA had no protective effect in the presence of 0.1 M NaCl. Poly(acrylates) bearing hydrophobic groups significantly increased IgG recovery after stress, independently of NaCl concentration, because of the synergistic effect of hydrophobic and electrostatic interactions. The AF4 results corroborate conclusions drawn from a previous study combining four analytical techniques. This study demonstrates that AF4 is an efficient tool for the analysis of protein formulations subjected to stress, an important achievement given the anticipated important role of proteins in near-future human therapies.

Prevention of thermally induced aggregation of IgG antibodies by noncovalent interaction with poly(acrylate) derivatives.

Prevention of thermal aggregation of antibodies in aqueous solutions was achieved by noncovalent association with hydrophobically modified poly(acrylate) copolymers. Using a polyclonal immunoglobin G (IgG) as a model system for antibodies, we have studied the mechanisms by which this multidomain protein interacts with polyanions when incubated at physiological pH and at temperatures below and above the protein unfolding/denaturation temperature, in salt-free solutions and in 0.1 M NaCl solutions. The polyanions selected were sodium poly(acrylates), random copolymers of sodium acrylate and N-n-octadecylacrylamide (3 mol %), and a random copolymer of sodium acrylate, N-n-octylacrylamide (25 mol %), and N-isopropylacrylamide (40 mol %). They were derived from two poly(acrylic acid) parent chains of Mw 5000 and 150000 g·mol(-1). The IgG/polyanion interactions were monitored by static and dynamic light scattering, fluorescence correlation spectroscopy, capillary zone electrophoresis, and high sensitivity differential scanning calorimetry. In salt-free solutions, the hydrophilic PAA chains form complexes with IgG upon thermal unfolding of the protein (1:1 w/w IgG/PAA), but they do not interact with native IgG. The complexes exhibit a remarkable protective effect against IgG aggregation and maintain low aggregation numbers (average degree of oligomerization <12 at a temperature up to 85 °C). These interactions are screened in 0.1 M NaCl and, consequently, PAAs lose their protective effect. Amphiphilic PAA derivatives (1:1 w/w IgG/polymer) are able to prevent thermal aggregation (preserving IgG monomers) or retard aggregation of IgG (formation of oligomers and slow growth), revealing the importance of both hydrophobic interactions and modulation of the Coulomb interactions with or without NaCl present. This study leads the way toward the design of new formulations of therapeutic proteins using noncovalent 1:1 polymer/protein association that are transient and require a markedly lower additive concentration compared to conventional osmolyte protecting agents. They do not modify IgG permanently, which is an asset for applications in therapeutic protein formulations since the in vivo efficacy of the protein should not be affected.

Bifunctional Polymer Hydrogel Layers As Forward Osmosis Draw Agents for Continuous Production of Fresh Water Using Solar Energy

The feasibility of bilayer polymer hydrogels as draw agent in forward osmosis process has been investigated. The dual-functionality hydrogels consist of a water-absorptive layer (particles of a copolymer of sodium acrylate and N-isopropylacrylamide) to provide osmotic pressure, and a dewatering layer (particles of N-isopropylacrylamide) to allow the ready release of the water absorbed during the FO drawing process at lower critical solution temperature (32 °C). The use of solar concentrated energy as the source of heat resulted in a significant increase in the dewatering rate as the temperature of dewatering layer increased to its LSCT more rapidly. Dewatering flux rose from 10 to 25 LMH when the solar concentrator increased the input energy from 0.5 to 2 kW/m(2). Thermodynamic analysis was also performed to find out the minimum energy requirement of such a bilayer hydrogel-driven FO process. This study represents a significant step forward toward the commercial implementation of hydrogel-driven FO system for continuous production of fresh water from saline water or wastewaters.

Fast Deswelling of Nanocomposite Polymer Hydrogels via Magnetic Field-Induced Heating for Emerging FO Desalination

Freshwater shortage is one of the most pressing global issues. Forward osmosis (FO) desalination technology is emerging for freshwater production from saline water, which is potentially more energy-efficient than the current reverse osmosis process. However, the lack of a suitable draw solute is the major hurdle for commercial implementation of the FO desalination technology. We have previously reported that thermoresponsive hydrogels can be used as the draw agent for a FO process, and this new hydrogel-driven FO process holds promise for further development for practical application. In the present work, magnetic field-induced heating is explored for the purpose of developing a more effective way to recover water from swollen hydrogel draw agents. The composite hydrogel particles are prepared by copolymerization of sodium acrylate and N-isopropylacrylamide in the presence of magnetic nanoparticles (γ-Fe2O3, <50 nm). The results indicate that the magnetic heating is an effective and rapid method for dewatering of hydrogels by generating the heat more uniformly throughout the draw agent particles, and thus, a dense skin layer commonly formed via conventional heating from the outside of the particle is minimized. The FO dewatering performance is affected by the loading of magnetic nanoparticles and magnetic field intensity. Significantly enhanced liquid water recovery (53%) is achieved under magnetic heating, as opposed to only around 7% liquid water recovery obtained via convection heating. Our study shows that the magnetic heating is an attractive alternative stimulus for the extraction of highly desirable liquid water from the draw agent in the polymer hydrogel-driven forward osmosis process.

Effect of particle size on the performance of forward osmosis desalination by stimuli-responsive polymer hydrogels as a draw agent

Stimuli-responsive polymer hydrogels have shown great potential for use as a draw agent in forward osmosis desalination. We have previously shown that the alteration of chemical structure of hydrogel network via the incorporation of ionic groups and light-absorbing particles can significantly improve the efficiency of hydrogels used as draw agent in FO desalination. In this study, particle size is demonstrated to be another key parameter in determining the efficacy of these materials as the draw media. Hydrogel copolymers of sodium acrylate and N-isopropylacrylamide of different particle sizes were prepared via free-radical polymerization and tested as draw agents. The results showed that the initial swelling rate of small particles (2–25μm) was much higher than that of large particles (e.g., 500–1000μm), with the diffusion mechanism shifted from non-Fickian to Fickian diffusion as the particle size decreases. To reclaim the fresh water drawn through the membrane by the polymer particles, the gas pressure and heating were applied as the stimuli on the draw agent to release water. Gas pressure was found to be an effective method of regaining the pure water, and is a more readily applicable method industrially than our previous mechanical pressing. It was found that greater liquid water recovery amounts were achieved from large hydrogel particles, whereas more water was recovered from smaller particles under such a thermal stimulus. This is likely due to the fact that hydrogel particles with different sizes showed different interstitial volumes, particle–particle contact areas, particle-membrane contact zones and hydrogel thickness on the membrane surface.

Physical chemistry of the conservation of cellulose fabric with water-soluble acrylic copolymers

The possibility of using water-soluble copolymers of sodium acrylate with acrylic acid esters for field conservation of cellulose-based textile materials by capillary impregnation was examined. Artificial aging of the composites obtained and its effect on the strength characteristics of the materials and on the conservation reversibility was examined.

Copolymerization of sodium acrylate with new acrylamide derivatives in the presence of water-soluble salts

Copolymerization of sodium acrylate with new acrylamide derivatives was studied. The copolymerization constants r1 and r2 of the monomers and the molecular weights of the copolymers were determined.

Ionotropically cross-linked pH-sensitive IPN hydrogel matrices as potential carriers for intestine-specific oral delivery of protein drugs

Background: The oral delivery of proteins and peptide drugs is considered a major challenge. These types of therapeutics are readily degraded, if taken orally, due to the harsh high acidity of stomach and enzymatic attack in the upper small intestinal tract. Methods: Water-soluble copolymers of sodium acrylate (AAs) grafted onto carboxymethyl cellulose (CMC) were prepared and characterized using Fourier transform spectroscopy, differential scanning calorimetry, and X-ray diffraction. The obtained graft copolymers were then used in a combination with sodium alginate to develop a new series of pH-sensitive interpenetrating polymeric network (IPN) hydrogels through ionotropic gelation with divalent ions (Ca2+). Morphology of the developed hydrogels was investigated using SEM. Swelling characteristics, at distinct compositions, were also studied at 37°C in two consecutive buffer solutions of pH 2.1 and 7.4 (similar to that of gastric and intestinal fluids, respectively). The release profiles of bovine serum albumin, as a model protein, from test IPN hydrogel films were studied in simulated gastric and intestinal fluids. In addition, the drug release process was confirmed by means of SEM. Results: Swelling studies of the developed IPN hydrogels at different pH values confirmed their pH-sensitive nature. The equilibrium swelling extents of the hydrogels were found to be dependent on the grafting yield of CMC/AAs graft copolymer. The IPN hydrogels attained equilibrium swelling percentages in the range 445–740%. In addition, the amount of bovine serum albumin released within 2 hours in pH 2.1 was relatively low (less than 18.1%). This amount increased up to 68% after 8 hours in pH 7.4. Conclusions: From the obtained preliminary data, it seems that the IPN hydrogels developed in this contribution can be tailored to act as good potential carriers for oral delivery of protein drugs. These hydrogels showed a promising protection of protein drugs from the harsh acidity of stomach and, at the same time, they conferred sustained drug release in the intestinal fluid.