Mass Ratio Of Acrylic Acid Research Articles

Clearance of methylene blue by CdS enhanced composite hydrogel materials

ABSTRACT Hydrogel material is considered to be one of the effective adsorbents widely used to remove organic pollutants. However, the poor mechanical properties of some hydrogels limit their applications. Herein, we prepared composite hydrogels, for which acrylic acid (AA) and acrylamide (AM) were cross-linked and polymerised as the main substrate with adsorption function, while CdS nanoparticles were mainly used as reinforced material. Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), two-dimensional infrared vibrational echo spectroscopy (2D-IR), and thermal gravimetric analyzer (TGA) were used to determine the physical and chemical structures of the hydrogels. The effects of the composition of AA, AM, and CdS on the mechanical properties and adsorption behaviours of the hydrogels were investigated. Besides, based on the great potential photocatalytic application value for wastewater remediation under the sunlight of CdS, the influence of the CdS doping amount on the photocatalytic property was also studied. As a result, when the mass ratio of AA to AM was 5:5, the hydrogel showed the best mechanical properties, and along with increasing the amount of CdS, the mechanical strength of the hydrogel was significantly enhanced from 0.445 MPa to 1.014 MPa. Besides, the composite hydrogels showed high adsorption and photocatalytic degradation synergistic clearance effect on methylene blue. Thus, the introduction of CdS photocatalytic nanoparticles may be an efficient and economical approach towards bifunctional hydrogel materials with enhanced mechanical property and photocatalytic degradation for wastewater remediation.

Preparation and Applications of Salt-Resistant Superabsorbent Poly (Acrylic Acid-Acrylamide/Fly Ash) Composite.

Solution polymerization synthesized alt-resistant superabsorbent poly (acrylic acid-acrylamide/fly ash) composites. The mass ratio of acrylic acid (AA) to acrylamide (AM), the concentration of crosslinker, the neutralization degree (ND) of AA, and the polymerization temperature were investigated by single-factor method. Optimized conditions for the synthesis of poly (acrylic acid-acrylamide/fly ash) (PAA-AM/FA) are, as following: m (AA)/m (AM) is 1.5, the content of crosslinker N, N-methylenebisacrylamide. (MBA) is 0.7%, neutralization degree of AA is 70%, polymerization temperature is 70 °C, and fly ash (FA) content is 50%. The prepared PAA-AM/FA demonstrated superior water absorption performance. The absorption capacities of PAA-AM/FA for pure water and 0.9% NaCl solution were found to be 976 g·g−1 and 81 g·g−1, respectively. Furthermore, PAA-AM/FA was found to have excellent adsorption capacity (148 mg·g−1) for Rhodamine B in water. Fourier Transform-Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) characterized the prepared materials. Results showed that fly ash was incorporated into the macromolecular polymer matrix and played a key role in improving the performance of the polymer composites.

Preparation and characterization of a binary‐graft‐based, water‐absorbing dust suppressant for coal transportation

ABSTRACTDuring coal transportation, a large amount of coal dust is generated; this not only leads to a massive loss of coal but also causes severe environmental pollution. In this research, we used a chemical modification approach to prepare a highly water‐absorbing dust suppressant. Corn starch, as the main ingredient, was copolymerized with acrylic acid and acrylamide, and acrylic acid and acrylamide were used to form a starch graft copolymer. Subsequently, in this research, we designed a suite of single‐factor experiments using the viscosity as the metric to determine the optimal reaction conditions, which were as follows: mass ratio of acrylic acid to acrylamide = 3:2, neutrality = 50%, reaction time = 3 h, and reaction temperature = 50 °C. Tests were carried out to assess the viscosity, water retention, and anti‐evaporation performance of the dust suppressant. The results indicate that when the dust‐suppressant concentration was 6%, the performance was optimized. Also, the anti‐evaporation behavior of the suppressant improved with the dust‐suppressant concentration. The use of this dust suppressant during coal transportation could greatly reduce dust dispersion and lead to improved environmental protection. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47065.

Synthesis and Water Absorbency Properties of Hydrogels Based on Lotus Root Starch

ABSTRACTIn order to increase the added value of lotus root starch, a new-style hydrogel was prepared by grafting copolymerization by acrylic acid (AA), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), K2S2O8, and N,N′- methylene-bis-acrylamide (MBA) in presence of lotus root starch. The molecular structure was characterized by Fourier transform infrared spectroscopy (FTIR). The different conditions that had an influence on the water absorbency are discussed, such as the ratio of initiator to monomers, the ratio of cross-linker to monomers, the mass ratio of AA and AMPS, the lotus root starch's mass, and the reaction temperature. For the product having the optimal water absorbency of 476 g/g, its water absorption kinetics diffusion model and equation were also researched. The material is friendly to the environment and is suggested to have significant potential to be used in various fields.

Preparing a Novel Superabsorbent Based on Carboxymethyl Biocomposite: An Optimization Study via Response Surface Methodology

A novel superabsorbent was prepared by utilizing carboxymethyl starch and carboxymethyl cellulose biocomposites as a grafting backbone. The scheme of the CMS-CMC double backbone structure was speculated. It was proposed that the superabsorbent possesses a three-dimensional network with an interpenetrating structure. The response surface methodology was used to optimize the parameters. Interactions among the most influential variables, i.e., the dosage of CMC, the acrylic acid to acrylamide mass ratio, and the neutralization degree of acrylic acid were estimated. A mathematical model was developed, which fit the experimental results well for all of the response variables. The optimal conditions included 28.8 % of CMC dosage, a 1.6 mass ratio of acrylic acid to acrylamide, and 73.4 % of neutralization degree of acrylic acid to achieve 815.2 g/g of water absorbency.

Synthesis and swelling properties of corn stalk‐composite superabsorbent

AbstractA corn stalk‐composite superabsorbent with water absorbency of 660 g/g within 30 min, was prepared by graft copolymerization with acrylic acid (AA), acrylamide (AM), sodium 4‐styrenesulfonate (SSS), and corn stalk in aqueous solution after the pretreatment of corn stalks (CS), using N,N‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) and sodium bisulfite (SBS) as redox initiators. Factors influencing water absorbency and gel strength of the superabsorbent composite, such as the amount of corn stalk, the mass ratio of acrylic acid to acrylamide, the degree of neutralization for AA and the amount of crosslinker, were investigated. Morphologies and structure of the corn stalk‐composite superabsorbents were characterized by FTIR, SEM and optical microscope. FTIR spectra indicate the structure of corn stalk graft‐copolymer. SEM data show that the discontinuous sheet structures of corn stalks disappear and gel aggregates with many large microporous holes and small capillary pores are formed after corn stalk graft modification. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Preparation and Water Absorbency of Superabsorbent Kaolin/PAA-AM Composite

In this paper, a novel superabsorbent composite material based on acrylic acid (AA), acrylic amide (AM) and inorganic kaolin was synthesized via solution polymerization in aqueous medium with N,N’-methylene bisacrylamide (MBA) as crosslinker and potassium persulfate (KPS) as initiator. The effects of water absorbency of the composite variables, such as neutralization, kaolin concentration and MBA concentration, on the water absorbency were systematically optimized. Evidence of compositing was obtained by a comparison of the Fourier transform infrared spectra of the initial reactants with that of the superabsorbent composites, and its complex structure was confirmed with scanning electron microscope. The water absorbing mechanism was also discussed. The results indicated that the superabsorbent composite material was successfully synthesized and the optimum reaction conditions were as follows: the neutralization degree was 80%, the dosage of kaolin, crosslinker and initiator were 4%, 0.11%, and 0.9% respectively and the mass ratio of AA and AM was 3∶2. The optimum absorbency of the superabsorbent composite material in distilled water could reach 815.6g/g.

Study on Preparation for Super Absorbent Polymer Using Cotton Waste

For the purpose of recycling of cotton waste cuttings and exploring the prospect of preparation for super absorbent polymer (SAP), the high viscosity carboxymethyl cellulose (CMC) was made from cotton waste first and then the SAP was synthesized by grafting acrylic acid (AA) onto the CMC with the potassium persulfate being as initiator, N, N'-methylene bis acrylamide as crosslinker. The impact of polymerization temperature, time, initiator dosage, AA concentration, crosslinker dosage, and neutralization degree on water absorbency of SAP was studied. The optimum conditions are mass ratio of AA and CMC 7.11 g/g, initiator dosage 0.03 g/g CMC, crosslinker dosage 0.2 g/100g AA, neutralization degree 80% and polymerization time 1.5 h at 70°C of the polymerization temperature. The water retention of the polymer is good and the water absorbency reaches up to 702.5 g/g.

Preparation, swelling, and stimuli‐responsive characteristics of superabsorbent nanocomposites based on carboxymethyl cellulose and rectorite

AbstractUtilization of naturally available raw materials for the fabrication of eco‐friendly functional materials has long been desired. In this work, a series of superabsorbent nanocomposites were prepared by radical solution copolymerization of sodium carboxymethyl cellulose (CMC), partially neutralized acrylic acid (NaA), and rectorite (REC) in the presence of initiator ammonium persulfate (APS) and crosslinker N,N'‐methylene‐bis‐acrylamide (MBA). The optimal reaction variables including the mass ratio of acrylic acid (AA) to CMC, MBA concentration, and REC content were explored. FTIR spectra confirmed that NaA had been grafted onto CMC and REC participated in polymerization. REC was exfoliated and uniformly dispersed in the CMC‐g‐PNaA matrix without agglomeration as shown by XRD, TEM, and SEM analysis. The thermal stability, swelling capabilities, and rate of the nanocomposites were improved after introducing REC, and the gel strength greatly depended on the concentration of crosslinker MBA. The nanocomposite showed excellent responsive properties and reversible On–Off switching characteristics in various saline, pH, and hydrophilic organic solvent/water solutions, which provided great possibility to extend the application domain of the superabsorbent nanocomposites such as drug delivery system. Copyright © 2010 John Wiley & Sons, Ltd.

Synthesis of Coal-Water Slurry Dispersant Based on Humic Acid

This paper focused on the preparation of the grafted modification of humic acid (HA) that was used in coal water slurry (CWS). By means of orthogonal experiment, the grafted humic acid was synthesized with acrylic acid (AA) copolymerized with humic acid, using potassium persulfate as the initiator in the reaction system. The structure of copolymer was characterized by ATR-FTIR. And then, the viscosity, liquidity, and stability of CWS used the dispersant based on the modified humic acid were determined through the CWS viscometer and tests of stability. The optimum conditions of synthesis are that the mass ratio of AA and HA is 0.35:1, dosage of initiator is 5%, reaction temperature of is 75°C, reaction time is 2.0h. Besides, when the dosage of active ingredient of the dispersant for CWS was 0.12%, the viscosity of CWS achieved lower.

The Synthesis of Graft Copolymer of Starch with Acrylic Acid and Acrylamide and its Application in Sand-Fixing

An Environmental friendly sand-fixing agent of water-borne polymer(graft copolymer of starch with acrylic acid and acrylamide)was synthesized. The influences of monomer dosage ratio, initiator dosage , the temperature and reaction time on the properties were discussed. The structure, thermal stability and morphology was characterized by IR spectra, TG-DTA and SEM, respectively. With the sand soil as research object, the tolerance of high temperature and compressive strength of the sand-fixing agent were studied preliminarily. The results show that when the mass ratio of acrylic acid to acrylamide is 15:10, the mass content of initiator is 4%, the reaction temperature is 50°C and time is 6h, the product has a good sand fixation performance for practical application.

PH-responsive carboxymethylcellulose-g-poly(sodium acrylate)/polyvinylpyrrolidone semi-IPN hydrogels with enhanced responsive and swelling properties

Novel pH-responsive semi-interpenetrated polymer network (semi-IPN) superabsorbent hydrogels were prepared by the radical graft polymerization of carboxymethylcellulose (CMC) and partially neutralized acrylic acid (NaA) in the presence of a crosslinker, N,N′-methylene-bis-acrylamide (MBA), and linear polyvinylpyrrolidone (PVP). FTIR spectroscopy showed that NaA was grafted onto the CMC backbone and PVP combined with CMC-g-PNaA network by hydrogen-bonding interaction. SEM showed that the formation of a semi-IPN structure improved the surface structure of the hydrogels. The reaction variables, including the mass ratio of acrylic acid (AA) to CMC, MBA concentration and PVP content were optimized, and the crosslinking density of the hydrogels was determined. In addition, the pH-response, swelling behavior of the hydrogel in various saline solutions and aqueous cetyltrimethylammonium bromide (CTAB) solutions were investigated. The results showed that the introduction of CMC and PVP clearly enhanced the swelling capability and rate, and improved the pH-responsive and On-Off switching swelling abilities, salt-resistance, and intriguing time-dependent swelling characteristics.

Graft Copolymerization of Artemisia Seed Gum with Acrylic Acid under Microwave and its Water Absorbency

A super‐absorbent polymer was prepared by grafting copolymerization of acrylic acid onto Artemisia seed gum, using microwave irradiation and ammonium persulfate as an initiator. The effect of various preparation conditions on its water absorbency, such as the ratio of acrylic acid to Artemisia seed gum, degree of acrylic acid neutralization, amount of initiator and microwave irradiation time, was investigated by orthogonal tests. The optimal reaction conditions were 3 min (irradiation time), 70% neutralization degree of acrylic acid and 2% initiator on the basis of the mass of acrylic acid used. When the mass ratio of acrylic acid to Artemisia seed gum is 5:0.5, the product has a water absorbency close to 400 times at room temperature in distilled water, this indicated that is has a high water absorbency. The structure of the graft copolymer was confirmed by Fourier transform infrared spectrometer (FT‐IR) and thermogravimetric analysis (TGA). Further more, this microwave irradiation processing method to prepare water absorbent materials has no industrial cast off produced, that is to say, this method is environmentally friendly.