Synthesis and absorbency of gelatin-graft-poly(sodium acrylate-co-acrylamide) superabsorbent hydrogel with saltand pH-responsiveness properties

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Ali Pourjavadi ◽  
Mohammad Sadeghi ◽  
Mohammad Mahmodi Hashemi ◽  
Hossein Hosseinzadeh
Keyword(s):  
Weight Ratio ◽  
Ammonium Persulfate ◽  
Switching Behavior ◽  
Polymerization Reaction ◽  
Sodium Acrylate ◽  
Swelling Kinetics ◽  
Superabsorbent Hydrogel ◽  
Swelling Capacity ◽  
Bioactive Agents ◽  
Kinetics Of

AbstractIn this article, we synthesize a novel gelatin-based superabsorbent hydrogel via graft copolymerization of mixtures of acrylic acid (AA) and acrylamide (AAm) onto gelatin backbones. The polymerization reaction was carried out in an aqueous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylene bisacrylamide (MBA) as a crosslinker. The hydrogel structures were confirmed by FTIR spectroscopy. The effect of grafting variables, i.e. concentration of MBA and APS, AA/AAm weight ratio, and reaction time and temperature, was systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The swelling behavior of these absorbent polymers was also investigated in various salt solutions. Results indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. Furthermore, the swelling of superabsorbing hydrogels was examined in solutions with pH values ranging between 1.0 and 13.0. It showed a reversible pH-responsive behavior at pHs 2.0 and 7.0. This on-off switching behavior makes the synthesized hydrogels an excellent candidate for controlled delivery of bioactive agents. Finally, the swelling kinetics of the synthesized hydrogels with various particle sizes was preliminarily investigated.

Preparation and swelling behaviour of a novel anti-salt superabsorbent hydrogel based on kappa-carrageenan and sodium alginate grafted with polyacrylamide

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Ali Pourjavadi ◽  
Hossein Ghasemzadeh ◽  
Hossein Hosseinzadeh
Keyword(s):  
Sodium Alginate ◽  
Graft Copolymerization ◽  
Weight Ratio ◽  
Homogeneous Solution ◽  
Water Soluble ◽  
Swelling Kinetics ◽  
Salt Solutions ◽  
Superabsorbent Hydrogel ◽  
Swelling Capacity ◽  
Kappa Carrageenan

Abstract A novel superabsorbent hydrogel was synthesized via crosslinking graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (κC) and sodium alginate (Na-Alg) backbones in a homogeneous solution. Methylenebisacrylamide (MBA) and potassium persulfate (KPS) were applied as water-soluble crosslinker and initiator, respectively. FTIR spectroscopy was used for confirming the structure of the final product. A mechanism for superabsorbent hydrogel formation was also suggested. The parameters affecting the swelling capacity of the synthesized hydrogel, i.e., κC-Alg weight ratio, concentration of AAm, MBA and KPS, as well as reaction temperature were systematically optimized for obtaining maximum absorbency. The swelling capacity of hydrogels was also measured in various salt solutions (LiCl, NaCl, KCl, MgCl2, CaCl2, SrCl2, BaCl2, and AlCl3). Due to their high swelling ability in salt solutions, the hydrogels may be referred to as ‘anti-salt superabsorbent’ polymers. The overall activation energy for the graft copolymerization reaction was found to be 374 kJ/mol. The swelling kinetics of the hydrogels in distilled water and in saline solution (0.9 wt.-% NaCl) was investigated.

Preparation, Swelling and Water-Retention Properties of Crosslinked Superabsorbent Hydrogels Based on Guar Gum

2010 ◽  
Vol 96 ◽  
pp. 177-182 ◽  
Author(s):  
Wen Bo Wang ◽  
Ai Qin Wang
Keyword(s):  
Acrylic Acid ◽  
Water Retention ◽  
Guar Gum ◽  
Weight Ratio ◽  
Ammonium Persulfate ◽  
Sodium Acrylate ◽  
Swelling Properties ◽  
Superabsorbent Hydrogel ◽  
Water Retention Properties ◽  
Superabsorbent Hydrogels

Utilization of natural polymer as matrix for preparing hydrogels can improve the performance of the materials and render them environmentally friendly. In this work, the guar gum-g-poly(sodium acrylate) (GG-g-PNaA) superabsorbent hydrogels were prepared by the solution graft copolymerization of natural guar gum (GG) with partially neutralized acrylic acid (NaA) using ammonium persulfate (APS) as initiator and N,N′-methylenebisacrylamide (MBA) as crosslinker. FTIR spectra confirmed that NaA had been grafted on GG chains. The effects of reaction variables including the concentration of APS and MBA, the weight ratio of acrylic acid (AA) to GG and the neutralization degree of AA on water absorption were investigated. The superabsorbent hydrogel prepared under optimal condition gives the best absorption of 1107 g∙g–1 in distilled water and 88 g∙g–1 in 0.9 wt% NaCl solution. Effects of external pH on the swelling properties of hydrogels were investigated, and the practical water retention properties of the hydrogels were also evaluated. Results indicated that the hydrogels exhibited excellent pH-stability in a wide pH range from 4 to 11, and the water-retention capabilities of sand soils were also greatly improved after utilizing the superabsorbent hydrogels. This superabsorbent hydrogels could be used as potential eco-friendly water-saving materials for agricultural or ecological application.

Gelatin-G-Poly(Sodium Acrylate-co-Acrylamide)/Kaolin Superabsorbent Hydrogel Composites: Synthesis, Characterisation and Swelling Behaviour

2007 ◽  
Vol 15 (5) ◽  
pp. 395-402 ◽  
Author(s):  
G. Bagheri Marandi ◽  
H. Hosseinzadeh
Keyword(s):  
Crosslinking Agent ◽  
Ammonium Persulfate ◽  
Organic Polymer ◽  
Sodium Acrylate ◽  
Swelling Kinetics ◽  
Water Absorbency ◽  
Salt Solutions ◽  
Superabsorbent Hydrogel ◽  
Superabsorbent Composite ◽  
Aqueous Salt Solutions

A novel superabsorbent hydrogel composite based on gelatin has been prepared by graft copolymerisation of acrylic acid and acrylamide in the presence of kaolin powder, using methylene-bisacrylamide (MBA) as a crosslinking agent and ammonium persulfate as an initiator. The synthetic variables affecting the water absorbency of the resulting superabsorbent composite were studied and the composite structure was confirmed using FT-IR spectroscopy. A new absorption band at 1728 cm−1 in the composite spectrum confirmed the presence of a kaolin-organic polymer linkage. The effect of kaolin content and MBA concentration showed that increasing these parameters decreased the water absorbency of the superabsorbent composite. The swelling measurements were conducted in aqueous salt solutions. Results indicated that the swelling ratios decreased with an increase in the ionic strength of the salt solutions. The pH of the various solutions also affected the swelling of the superabsorbent. Finally, the swelling kinetics of synthesised composites with various absorbent particle sizes was briefly examined.

Copolymerization Kinetics of Polyetyhylenglycol Allylether Type Polycarboxylate Superplasticizer

2014 ◽  
Vol 936 ◽  
pp. 1393-1398 ◽  
Author(s):  
Ying Feng Tian ◽  
Xia Ping Zhu ◽  
Ya Ting Deng ◽  
Kui Wang
Keyword(s):  
Ammonium Persulfate ◽  
Radical Copolymerization ◽  
Polymerization Reaction ◽  
Molar Ratio ◽  
Free Radical Copolymerization ◽  
H Nmr ◽  
Polycarboxylate Superplasticizer ◽  
Relationship Of ◽  
Kinetics Of ◽  
Copolymerization Kinetics

The free radical copolymerization kinetics of polyethylenglycol allylether (APEG) with acrylic acid (AA) had been studied in aqueous solution through using ammonium persulfate (APS) and 30% hydrogen peroxide (H2O2) as initiators. The structure of polycarboxylate superplasticizer had been characterized by IR and 1H-NMR. The rate of copolymerization was proportional to the molar ratio of monomers (AA:APEG) to the power of 0.4405, and to the amount of initiator (1.5%APS-2%H2O2, mass ratio to monomers) to the power of 0.7819, respectively. The overall observed activation energy of copolymerization was 45.048 kJ/mol. The kinetic relationship of copolymerization reaction of APEG with AA had been established as follow: Rp∝[APEG/AA]0.4405[APS-30%H2O2]0.7819e-5418/T. The temperature and initiator were main influencing factors on polymerization reaction.

Synthesis and Swelling Behaviors of Poly (sodium acrylate)/Hydroxyapatite Superabsorbent Nanocomposites

2010 ◽  
Vol 96 ◽  
pp. 227-232 ◽  
Author(s):  
Jin Lei Wang ◽  
Yi An Zheng ◽  
Ai Qin Wang
Keyword(s):  
Electron Microscopy ◽  
Ammonium Persulfate ◽  
Polymerization Reaction ◽  
Sodium Acrylate ◽  
Tem Analysis ◽  
Oh Groups ◽  
Transmission Electron ◽  
Swelling Rate ◽  
Radical Solution ◽  
Swelling Behaviors

Superabsorbent nanocomposites based on partially neutralized acrylic acid (AA) and hydroxyapatite (HP) were prepared by free radical solution polymerization using N, N′-methylenebisacrylamide (MBA) as the crosslinker and ammonium persulfate (APS) as the initiator. The developed nanocomposites were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of HP content on water absorbency of the nanocomposites were investigated, and the swelling behaviors of the nanocomposites in various pH solutions and their reswelling capability in distilled water were also systematically evaluated. FTIR spectra revealed that the P–OH groups of HP participated in graft polymerization reaction with AA. TEM analysis showed the needle-like crystals of HP present in the PAA/HP nanocomposite with a diameter of about 40 nm and a length of about 270 nm. The swelling rate and reswelling capability of the superabsorbents were improved due to the introduction of HP into PAA polymeric network, and this result implied that the nanocomposites acted as a recyclable water-saving material.

scholarly journals Synthesis and Characterization of Superabsorbent Hydrogels From Waste Bovine Hair Via Keratin Grafted With Acrylic Acid (AA) and Acrylamide (AAm)

2021 ◽  
Author(s):  
Aysegul Uzuner Demir ◽  
Fatih Arican ◽  
Aykut Sancakli ◽  
Ezgi Ismar
Keyword(s):  
Acrylic Acid ◽  
Crosslinking Agent ◽  
Value Added ◽  
Ammonium Persulfate ◽  
Leather Industry ◽  
Reaction Conditions ◽  
Superabsorbent Hydrogel ◽  
Swelling Capacity ◽  
Crosslinking Agents

Abstract The leather industry, due to its way of using chemicals during treatment and releasing them back to the environment makes it one of the hazardous sectors. It is not only releasing the chemicals also during the process precious biomass such as collagen and keratin discarded as waste. In this study, bovine hair which occurs during the treatments of the bovine leather process is supplied as waste and converted to superabsorbent hydrogel via grafting of keratin with monomers (Acrylic Acid (AA), Acrylamide (AAm)) in the presence of N, N'-methylene bisacrylamide (NMBA) used as a crosslinking agent and ammonium persulfate (APS) as an initiator. Keratin is selected to enhance the biocompatibility of the hydrogel. Thus, different keratin/monomer ratios, crosslinking agents, and initiator amounts were accepted as variables, and reaction conditions were optimized to achieve the highest swelling capacity. Synthesized hydrogels were chemically, morphologically, and thermally characterized via Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimeter (DSC), and thermal gravimetric analyzer (TGA). FTIR, DSC, and TGA results confirmed the grafted structure. The maximum swelling ratio was recorded at pH 9, at the end of 48 hours as 1791%. Sponge-like hydrogels were successfully obtained, and waste keratin is successfully valorized by means of hydrogels which can be used in high-value-added areas.

scholarly journals Polyelectrolyte Gels: A Unique Class of Soft Materials

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 102
Author(s):  
Ferenc Horkay
Keyword(s):  
Exchange Process ◽  
Interaction Strength ◽  
Soft Materials ◽  
Industrial Applications ◽  
Future Research ◽  
Swelling Kinetics ◽  
Polyelectrolyte Gels ◽  
Ion Exchange Process ◽  
Counter Ions ◽  
Kinetics Of

The objective of this article is to introduce the readers to the field of polyelectrolyte gels. These materials are common in living systems and have great importance in many biomedical and industrial applications. In the first part of this paper, we briefly review some characteristic properties of polymer gels with an emphasis on the unique features of this type of soft material. Unsolved problems and possible future research directions are highlighted. In the second part, we focus on the typical behavior of polyelectrolyte gels. Many biological materials (e.g., tissues) are charged (mainly anionic) polyelectrolyte gels. Examples are shown to illustrate the effect of counter-ions on the osmotic swelling behavior and the kinetics of the swelling of model polyelectrolyte gels. These systems exhibit a volume transition as the concentration of higher valence counter-ions is gradually increased in the equilibrium bath. A hierarchy is established in the interaction strength between the cations and charged polymer molecules according to the chemical group to which the ions belong. The swelling kinetics of sodium polyacrylate hydrogels is investigated in NaCl solutions and in solutions containing both NaCl and CaCl2. In the presence of higher valence counter-ions, the swelling/shrinking behavior of these gels is governed by the diffusion of free ions in the swollen network, the ion exchange process and the coexistence of swollen and collapsed states.

Graft Copolymerization of Acrylamide onto Activated Starch Using Inverse Emulsion Polymerization

2011 ◽  
Vol 308-310 ◽  
pp. 600-605
Author(s):  
Dian Mo Zheng ◽  
Sheng Gan Zhu ◽  
Li Ping Wu
Keyword(s):  
Ball Milling ◽  
Graft Copolymerization ◽  
Chemical Reactivity ◽  
Weight Ratio ◽  
Monomer Conversion ◽  
Ammonium Persulfate ◽  
Grafting Efficiency ◽  
Inverse Emulsion ◽  
Initiation System ◽  
Ft Ir

Activated starch was prepared by ball milling before used. Graft copolymerization of acrylamide onto activated starch was carried out in inverse emulsion using a redox initiation system of ammonium persulfate and sodium bisulfite. The effects of ball-milling time, reaction temperature, initiator concentration and weight ratio of acrylamide to starch on the conversion of monomer, grafting percentage and grafting efficiency were studied. The structure and properties of the graft copolymer and activated starch were characterized by FT-IR, XRD and SEM. The results showed that ball milling could progressively destroy the crystalline structure of starch and improve the chemical reactivity. The monomer conversion, grafting percentage and grafting efficiency of grate copolymerization were 96.6%、62.4%、85.49%, respectively.

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