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.

Preparation and Characterization of Kenaf-Based Superabsorbent Polymers

2011 ◽  
Vol 183-185 ◽  
pp. 1812-1816
Author(s):  
Dan Wang ◽  
Zhan Qian Song ◽  
Shi Bin Shang ◽  
Zhan Jun Wang ◽  
Myoung Ku Lee
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Graft Copolymerization ◽  
Ph Value ◽  
Crosslinking Agent ◽  
Ammonium Persulfate ◽  
Deionized Water ◽  
Superabsorbent Polymers ◽  
Saline Solutions

Novel kenaf-based superabsorbent polymers (SAPs) were prepared by grafting acrylic acid (AA) and acrylamide (AM) onto kenaf cellulose. Graft copolymerization was carried out in aqueous solution using N, N’-methylenebisacrylamide (NMBA) as crosslinking agent and sodium bisulfite (NaHSO3) and ammonium persulfate ((NH4)2S2O8) as initiator. The SAPs so obtained were examined by SEM. The absorbency of SAPs consists of different kenaf cellulose in deionized water, saline solutions and different pH value solutions were investigated.

The Effects of Acrylamide Loading on the Swelling Capacity of Superabsorbent Polymer in Different Aqueous Medium

2013 ◽  
Vol 812 ◽  
pp. 20-29 ◽  
Author(s):  
Mohamed Nur Raihan ◽  
Nadras Othman ◽  
Ahmad Zulkifli ◽  
Fauzi Roslinda
Keyword(s):  
Aqueous Medium ◽  
Crosslinking Agent ◽  
Dry Weight ◽  
Urea Solution ◽  
Distilled Water ◽  
Superabsorbent Polymer ◽  
Potassium Persulphate ◽  
Superabsorbent Hydrogel ◽  
Waste Polystyrene ◽  
Swelling Capacity

Superabsorbent polymer from waste polystyrene-graft-polyacrylamide was synthesized through emulsion polymerization technique using acrylamide as a monomer and potassium persulphate as an initiator in the presence of N,N-methylenebisacrylamide (NMBA) as a crosslinking agent. The effects of acrylamide loading was investigated to obtain the optimum condition that shows the best swelling capacity in three different aqueous medium; distilled water, saline solution and urea solution. Superabsorbent hydrogel were characterized by Fourier Transform Infrared (FTIR), thermogravimetric analysis (TGA) and electron scanning microscopy (SEM). Swelling test showed optimum absorbencies for distilled water, saline and urea solution were 1230 wt%, 1160 wt% and 440 wt% from their dry weight, respectively, recorded at ratio 1:10 of waste polystyrene to acrylamide. Meanwhile, the IR Spectroscopy proves that the grafting process between acrylamide and waste polystyrene was occurred in the hydrogel. Thermal degradation of the hydrogel started at 350 °C and the existence of porous unit can be observed in SEM micrographs.

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.

Superabsorbent Hydrogel from Sago Starch: The Effects of Crosslinking Agent on Thermal Stability and FTIR Analysis

2012 ◽  
Vol 567 ◽  
pp. 174-177
Author(s):  
O. Nurizan ◽  
A. Zuraida ◽  
N. Norhuda Hidayah
Keyword(s):  
Thermal Stability ◽  
Crosslinking Agent ◽  
Ammonium Persulfate ◽  
Sago Starch ◽  
Superabsorbent Hydrogel ◽  
Polymer Hydrogels ◽  
Grafted Copolymer ◽  
Redox Initiator ◽  
Initiator System ◽  
Polymerization Method

For several decades, superabsorbent polymer hydrogels had attracted the researchers’ attention due to its afforded unique environmental and commercial advantages. This paper reported the study on the effect of cross linker on the sago starch superabsorbent hydrogel (SSH), prepared via graft co-polymerization method of acrylic acid (AA) onto sago starch (SS). The AA grafted copolymer was obtained via a redox initiator system of ammonium persulfate (APS) and in the presence of N, N’ - methylenebisacrylamide (N-MBA) crosslinker. Fourier Transform infrared spectroscopy (FTIR) spectra proved that AA was grafted onto SS. The thermal stability of SSH is increases with the addition of crosslinker.

The Study on the Preparation and Characterization of Crosslinked Polyvinyl Alcohol Microspheres

2013 ◽  
Vol 716 ◽  
pp. 337-342
Author(s):  
Yun Feng Yang ◽  
Bao Jiao Gao ◽  
Su Yu Liu
Keyword(s):  
Particle Size ◽  
Polyvinyl Alcohol ◽  
Crosslinking Agent ◽  
Influence Factors ◽  
Microemulsion Polymerization ◽  
Reaction Conditions ◽  
The Matrix ◽  
Inverse Microemulsion ◽  
Inverse Microemulsion Polymerization

Linear polyvinyl alcohol ( PVA ) as the matrix, Glutaraldehyde as crosslinking agent, the crosslinked polyvinyl alcohol microspheres ( CPVA ) was prepared by inverse microemulsion polymerization. Influence factors for forms and particle size of crosslinking spheres such as the ratio of oil and water, reaction temperature and time, crosslinking agent and catalyst use level, stirring speed. When reaction conditions changed, the particle size would change accordingly.

scholarly journals Study on superabsorbent composites XVII. Preparation and characterization of poly(acrylic acid)/attapulgite/Namontmorillonite superabsorbent composites

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Junping Zhang ◽  
Kun Zhang ◽  
Aiqin Wang
Keyword(s):  
Acrylic Acid ◽  
Surface Morphology ◽  
Crystalline Structure ◽  
Great Influence ◽  
Clay Content ◽  
Ammonium Persulfate ◽  
Water Absorbency ◽  
Superabsorbent Composite ◽  
Superabsorbent Composites

AbstractA novel superabsorbent composite simultaneously incorporated with both attapulgite and Na-montmorillonite was prepared by aqueous polymerization using N,N’-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. The effects of the clay content on swelling ability of the superabsorbent composite were investigated. The superabsorbent composite were characterized by IR, XRD and SEM. The results indicate that Na-montmorillonite was exfoliated in the composite, whereas, attapulgite kept its crystalline structure. The content of clay has great influence on surface morphology and water absorbency of the superabsorbent composite, and the collaborative effect of attapulgite and Namontmorillonite on swelling ability is superior to that of single one.

scholarly journals Synthesis and characterization of a novel sugar based cross-linker

2020 ◽  
Vol 65 (9) ◽  
pp. 801-806
Author(s):  
ANAMICA ◽  
◽  
Poorn Prakash PANDE ◽  
Keyword(s):  
Acrylic Acid ◽  
Allyl Chloride ◽  
Basic Medium ◽  
Polymer Gel ◽  
Atmospheric Conditions ◽  
Aqueous Gels ◽  
Swelling Capacity ◽  
Ft Ir ◽  
Cross Linker

There are very few literature reports on the synthesis of monosaccharide based cross-linkers. A novel monosaccharide sugar-based cross-linker was synthesized by using D-mannitol, and allyl chloride in basic medium at low temperature (40°C) under inert atmospheric conditions. We have used a new synthetic scheme which does not involve the use of autoclave at high temperature and pressure for carrying out allylation with allyl chloride. The synthesized product has been characterized by, Fourier-transform infrared (FT-IR) spectra and 1 H Nuclear magnetic resonance (1 HNMR) spectra. The formation of allyl mannitol was also confirmed with the help of elemental analysis of C, H and O. Cross linked polymer gel samples were prepared by polymerizing acrylic acid monomer alongwith the synthesized cross-linker at different concentrations. Aqueous gels have been prepared from the cross-linked polymers and their swelling capacity has been studied. It has been found that these gels act as superabsorbent materials. The optimum ratio of cross-linker and acrylic acid monomer for the preparation of gel having highest swelling capacity (~ 28000% of water) was found to be 0.03 g crosslinker with 12.0 g. monomer.

Characterization of cross-linked chitosan by ionic and covalent crosslinking agents as wall material of red ginger oleoresin microcapsules

2021 ◽  
pp. 3380-3388
Author(s):  
Jayanudin Jayanudin ◽  
Rochmadi Rochmadi ◽  
Fahrurrozi Moh. ◽  
Sang Kompiang Wirawan
Keyword(s):  
Corn Oil ◽  
Sodium Tripolyphosphate ◽  
Crosslinking Agent ◽  
Chitosan Solution ◽  
Wall Material ◽  
Covalent Crosslinking ◽  
Red Ginger ◽  
Covalent Interactions ◽  
Crosslinking Agents

The aim of this study was to determine the characterization of ionic and covalent interactions to form a crosslinking network with chitosan as a wall material of microcapsules. Red ginger oleoresin microcapsule was prepared by emulsion crosslinking method. Red ginger oleoresin was mixed and stirred with chitosan solution to form an emulsion, then added to corn oil and stirred again to form a second emulsion. Crosslinking agents of glutaraldehyde saturated toluene (GST) or sodium tripolyphosphate (TPP) solution was slowly added to the emulsion. When using a crosslinking agent of TPP solution was added glacial acetic acid to adjust pH. Red ginger oleoresin microcapsules were filtered and washed with petroleum ether followed by n-hexane and then dried in an oven. Microcapsules from chitosan that are cross-linked with GST produce higher yield and size of microcapsules compared to TPP. Whereas, the highest encapsulation efficiency produced from chitosan cross-linked with TPP was 91.63±0.02%. Meanwhile, the highest cumulative release was obtained from TPP cross-linked chitosan microcapsules of 63.71% and the lowest was 50.01% from chitosan microcapsules that cross-linked with GST. The conclusion of this study was the differences between ionic and covalent crosslinking agents produce different microcapsule characteristics. Microcapsules from chitosan cross-linked with GST generated more compact with a smoother surface than with TPP.

scholarly journals Synthesis and Characterization of SiO2Nanoparticles and Their Efficacy in Chemical Mechanical Polishing Steel Substrate

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
M. J. Kao ◽  
F. C. Hsu ◽  
D. X. Peng
Keyword(s):  
Chemical Mechanical Polishing ◽  
High Selectivity ◽  
Steel Substrate ◽  
Sol Gel ◽  
Aerospace Industry ◽  
Value Added ◽  
Mechanical Polishing ◽  
Reaction Conditions ◽  
Abrasive Size

Chemical mechanical polishing (CMP) technology is extensively used in the global planarization of highly value-added and large components in the aerospace industry. A nanopowder of SiO2was prepared by the sol-gel method and was compounded into polishing slurry for the CMP of steel substrate. The size of the SiO2abrasives was controlled by varying the sol-gel reaction conditions. The polishing efficacy of nano-SiO2was studied, and the CMP mechanism with nanosized abrasives was further investigated. The proposed methods can produce SiO2abrasives whose size can be controlled by varying the sol-gel reaction conditions. The size of the SiO2abrasives was controlled in the range from 58 to 684 nm. The roughness of the steel substrate strongly depends on the size of the abrasive, and the surface roughness decreases as the abrasive size declines. A super-smooth surface with a roughness of 8.4 nm is obtained with nanosized SiO2. Ideal CMP slurry can be used to produce material surfaces with low roughness, excellent global planarization, high selectivity, an excellent finish, and a low-defected rate.

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