Potassium Acrylate Research Articles

Synthesis and Swelling Behaviors of Wheat Straw Cellulose-g-Poly (Potassium Acrylate)/PDMDAAC Amphoteric Semi-IPNs Superabsorbent Resin

A novel superabsorbent resin (SAR) which was called wheat straw cellulose-g-poly (potassium acrylate)/poly-diallyl dimethyl ammonium-chloride (WSC-g-PKA/PDMDAAC) semi-interpenetrating polymer networks (semi-IPNs) amphoteric SAR was synthetized by graft polymerization and semi-interpenetrating technology with the present of initiator and crosslinker. The effects of AA, PDMDAAC and crosslinker content on water absorbency of semi-IPNs SAR were studied. The semi-IPNs SAR prepared under optimized synthesis condition gave the best water absorption of 210.57 g/g in distilled water and 22.13 g/g in 0.9 wt% NaCl solution. In addition, the results showed that high water absorbency appeared from pH 4 to 9, and the effect of the salt ions in the swelling capacity was Al3+ > Ca2+ > Mg2+ > K+ > Na+.

Synthesis and swelling behaviors of semi‐IPNs superabsorbent resin based on chicken feather protein

ABSTRACTA novel chicken feather protein‐g‐poly (potassium acrylate)/polyvinyl alcohol (CFP‐g‐PKA/PVA) semi‐IPNs superabsorbent resin (SAR) based on feather protein, acrylic acid (AA), and polyvinyl alcohol (PVA) was synthesized by graft copolymerization and semi‐interpenetrating technology. The results from FTIR, SEM, and TGA analysis showed that both CFP and PVA reacted with PKA during the polymerization process. The effects of AA, PVA, initiator and crosslinker content on water absorbency of semi‐IPNs SAR were studied. The swelling behavior in various pHs and saline solutions were also investigated. The water absorbency of SAR reached the maximum at pH = 6. The effect of the five cations on swelling had the following order: Al3+ > Ca2+ > Mg2+ > K+ > Na+. The highest water absorbency in distilled water and 0.9 wt % NaCl solutions were 714.22 and 70.08 g g−1, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39748.

Preparation of wheat straw based superabsorbent resins and their applications as adsorbents for ammonium and phosphate removal

A novel wheat straw cellulose-g-poly (potassium acrylate)/polyvinyl alcohol (WSC-g-PKA/PVA) semi-interpenetrating polymer networks (semi-IPNs) superabsorbent resin (SAR) was prepared by graft copolymerization. The structure and performance of the WSC-g-PKA/PVA semi-IPNs SAR was studied and compared with those of wheat straw cellulose-g-poly (potassium acrylate) (WSC-g-PKA) SAR. The effects of various experimental parameters such as solution pH, concentration, contact time and ion strength on NH4(+) and PO4(3-) removal from solutions were investigated. Equilibrium isotherm data of adsorption of both NH4(+) and PO4(3-) were well fitted to the Freundlich model. Kinetic analysis showed that the pseudo-second-order kinetic model was more suitable for describing the whole adsorption process of NH4(+) and PO4(3-) on SARs. Overall, WSC-g-PKA/PVA semi-IPNs SAR showed better properties in comparison with WSC-g-PKA SAR and it could be considered as one efficient material for the removal and recovery of nitrogen and phosphorus with the agronomic reuse as a fertilizer.

Poly(acrylamide-co-acrylate)/rice husk ash hydrogel composites. II. Temperature effect on rice husk ash obtention

Superabsorbent hydrogel composites based on poly(acrylamide-co-acrylate) and rice husk ash (RHA) were prepared by free-radical copolymerization in aqueous media, using N,N-methylenebisacrylamide (MBA), as crosslinker and potassium persulfate (K2S2O8), as initiator. The effect of calcination temperatures (400–900°C) for obtaining RHA was evaluated. FTIR, WAXS, SEM–EDS and TGA were applied to characterize a series of hydrogels filled with RHA. The hydrogels composites were formed with constant amounts of RHA (10wt.%) and crosslinking agent (0.1mol-%) in relation to the relative to the total mass of acrylamide (AAm) and potassium acrylate (KAc) monomers (50–50mol-%). A blank sample of poly(acrylamide-co-acrylate) hydrogel without RHA was used as control. A superabsorbent hydrogel composite, with a maximum absorption Weq>1000 gwater/gabsorbent, was obtained with the RHA calcined at 900°C. In addition, the hydrogel composite showed to be sensitive to the pH variation and to the presence of salts in the swelling media. From the results, it is possible to infer that the poly(acrylamide-co-acrylate)/RHA hydrogel composites presented good characteristics to be applied as soil conditioner for using in agriculture.

Synthesis of wheat straw cellulose-g-poly (potassium acrylate)/PVA semi-IPNs superabsorbent resin

To better use wheat straw and minimize its negative impact on environment, a novel semi-interpenetrating polymer networks (semi-IPNs) superabsorbent resin (SAR) composed of wheat straw cellulose-g-poly (potassium acrylate) (WSC-g-PKA) network and linear polyvinyl alcohol (PVA) was prepared by polymerization in the presence of a redox initiating system. The structure and morphology of semi-IPNs SAR were characterized by means of FTIR, SEM and TGA, which confirmed that WSC and PVA participated in the graft polymerization reaction with acrylic acid (AA). The factors that can influence the water absorption of the semi-IPNs SAR were investigated and optimized, including the weight ratios of AA to WSC and PVA to WSC, the content of initiator and crosslinker, neutralization degree (ND) of AA, reaction temperature and time. The semi-IPNs SAR prepared under optimized synthesis condition gave the best water absorption of 266.82g/g in distilled water and 34.32g/g in 0.9wt% NaCl solution.

Phase Transition of Poly(acrylic acid-co-N-isopropylacrylamide) Core-shell Nanogels

A series of poly(acrylic acid) macromolecular chain transfer agents with different molecular weights were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization and characterized by 1H NMR and gel permeation chromatography. Multiresponsive core-shell nanogels were prepared by dispersion polymerization of N-isopropylacrylamide in water using these poly(potassium acrylate) macro-RAFT agents as the electrosteric stabilizer. The size of the nanogels decreases with the amount of the macro-RAFT agent, indicating that the surface area occupied by per polyelectrolyte group is a critical parameter for stabilizing the nanogels. The volume phase transition and the zeta potentials of the nanogels in aqueous solutions were studied by dynamic light scattering and zetasizer analyzer, respectively.

A novel thermo and pH-double sensitive hydrogel immobilized Pd catalyst for Heck and Suzuki reactions in aqueous media

A novel Hydrogel (1) was prepared from N-isopropylacrylamide, 4-vinylpyridine and potassium acrylate by free radical cross-linking polymerization. Hydrogel (1) showed both thermosensitivity and pH-sensitivity, and exhibited high swelling capacity in water. Because Hydrogel (1) has porous structure in its network and good loading performance with Pd2+, it was used as “microreactor” for immobilization of metal nanoparticles. We chose Heck and Suzuki reaction of aryl halides in water as test reaction to probe the catalytic activity of such Hydrogel (1) supported palladium catalyst. As a result, the Hydrogel (1)-Pd (II) catalyst exhibited good catalytic activity in both Heck and Suzuki reactions. Moreover, the Hydrogel (1)-Pd (II) catalyst was easily recovered and recycled. The reuse experiments showed that it was recycled six times without obviously losing of catalytic activity.

Swelling and contraction of ferrogels based on polyacrylamide in a magnetic field

The equilibrium swelling of magnetoactive ferrogels based on the copolymer of acrylamide with 10% potassium acrylate in water is studied. The gels are filled with strontium ferrite and/or magnetite taken in amounts of 20, 40, 60, and 80 parts per 100 parts of the polymer by weight. In the absence of a magnetic field, as the content of the filler is increased, the degree of swelling tends to increase for the gels containing strontium ferrite and to decrease for the magnetite-containing gels. In the structure of hydrogels, strontium ferrite particles possessing a permanent magnetic moment form a microscopic network from chain aggregates, while the particles of magnetite, a magnetically soft material, give rise to disordered aggregates. The enthalpy of hydration of ferrogel polymeric matrices weakly depends on the nature and amount of the introduced filler: The interaction parameter takes small positive values in the range 0.10–0.18. In a homogeneous magnetic field of 365 mT, the degree of swelling decreases at a small filler content for both types of ferrogels. This effect is accompanied by elongation of a ferrogel sample along the field direction and contraction in the transverse direction. With an increase in the filler content, the inversion of both effects occurs. The applicability of concepts about the homogeneously magnetizable continuous medium to the process of magnetostriction of ferrogels is analyzed.

Smart Hydrogels Based on Modified Gum Arabic as a Potential Device for Magnetic Biomaterial

AbstractBy means of a conventional cross‐linking/co‐polymerization reaction of modified gum arabic (M‐GA), acrylamide (AAm), and potassium acrylate (KAAc) in the presence of magnetite (Fe3O4) nanoparticles, a magnetic field‐sensitive M‐GA‐based hydrogel (smart hydrogel) was synthesized to investigate its potential as a magnetic biomaterial and as a intelligent hydrogel. Characterizations through FT‐IR, NMR, XRD, Mössbauer, SEM, and EDX inferred that the smart hydrogel was efficiently formed. Theoretically, the smart hydrogel obtained in this work may effectively be applied as biomaterial either on remote controlled release or tissue engineering or even in other areas of science and technology.magnified image

Undesirable effects of heating on hydrogels

AbstractHeating is the most conventional drying method for removing water from as‐synthesized hydrogels in laboratory and industry. In this article, the effects of the heating temperature (60–200°C) and time (10 min–24 h) on swelling properties of highly absorbent hydrogels based on 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS), acrylic acid (AA), potassium acrylate (KA), and acrylamide (AM) were studied. Crosslinkers methylene bisacrylamide (MBA) and poly(ethyleneglycol) dimethacrylate (PEGDMA) were used in the syntheses. Depending on the hydrogel structural composition and its drying temperature and time, the swelling capacities were extremely changed. Generally, AA‐, KA‐, and AM‐based hydrogels showed more hydrolytic‐thermal stability than the corresponding AMPS‐based hydrogels. MBA‐crosslinked hydrogels generally exhibited higher vulnerability against heating. Swelling of PEGDMA‐crosslinked poly(AM‐KA‐AA) hydrogel was greatly increased after heating, whereas its analogousAM‐free sample exhibited huge loss of swelling. PEGDMA‐crosslinked poly(AMPS) samples also exhibited swelling reduction after drying. Rheological studies showed that the storage modulus was highly reduced (∼ 5200 Pa) after heating of MBA‐crosslinked poly(AMPS) hydrogels, which reconfirmed the crosslink cleavage. Mechanistic discussions were proposed for the thermal‐induced swelling changes. It was concluded that the chemical nature of both crosslinker and monomer must be taken into consideration to choose the temperature and time of the hydrogel drying. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Evaluating hydrogels for agriforestry applications

Hydrogels synthesised by inverse suspension polymerisation (ISP) technique consisting of acrylamide and potassium acrylate interlinked with N, N’ methylene-bis-acrylamide and presenting different behavior in terms of rooting ability and speed, elastic module and release properties were studied. Markedly clayey soil properties were modified by drawing up moisture-retention curves using ceramic plate pressure waves and developing montages for evaluating modifications made to their retention, regarding prolonged and instantaneous irrigation-water dosage conditions. Acacia and radish crops were grown in nursery phase in soil conditioned with different hydrogels. Delayed specie withering was simultaneously evaluated in the first crop and difference in growth in the second one. Follow-up of in situ soil moisture content was also evaluated over a fixed period of time. A method was achieved for measuring elastic module and release properties and model was established for predicting hydrogel behavior in soil having known basic properties in free state. The results revealed the usefulness of hydrogels in such applications: greater facility in usable water release and retention by soil, notable delay in withering in hostile conditions and greater growth of species. Guidelines were also established for defining the characteristics of hydrogel more adequately, depending on the desired application and a projection was made concerning reducing water consumption for maintaining a particular crop.

Synthesis and Properties of Lightly Crosslinked Poly((meth)acrylic acid) Microparticles Prepared by Free Radical Precipitation Polymerization

Microparticles composed of (meth)acrylic acid, potassium (meth)acrylate, and trifunctional pentaerythritol were prepared using a thermally initiated free radical precipitation polymerization in ethyl acetate. The particle synthesis method was investigated, and the structure and morphology of the microparticles was evaluated using Fourier transform infrared spectroscopy and scanning electron microscopy. Results indicate that the physicochemical properties of the microparticles are dependent on the crosslinking ratio and type of carboxylic acid monomer employed in the polymerizations. The glass transition temperature behavior is significantly affected by the monomer type and the amount of crosslinking agent employed. The swelling dynamics of the microparticles are also pH, monomer, and crosslinking ratio dependent.

New Super‐Absorbing Hydrogel Hybrids from Gum Arabic and Acrylic Monomers

Novel super‐absorbing hydrogel hybrids composing arabic gum (AG) and acrylamide (AM)/acrylic acid (AA)‐potassium acrylate (AK) were prepared using a highly practical, homogenous solution polymerization process, conducted under normal atmospheric conditions. The unique characteristics of the gum and the redox pair initiating system (persufate/metabisulfite) favored the crosslinking polymerization, run under concentrated conditions without a need to heat. To produce hydrogel hybrids having the highest gel content and the highest swelling capacity, the preparative process was systematically studied through investigation of the certain reaction variables, i.e., the concentration of AG, initiator, crosslinker, monomer, and AM/AA‐AK mole ratio. The spectral and thermal characteristics of the optimally prepared hydrogel were studied using FTIR spectroscopy and thermogravimetric analysis, respectively.

Synthesis of ABA triblock copolymer of poly(potassium acrylate-styrene-potassium acrylate) by atom transfer radical polymerization and the self-assembly in selective solvents

A series of well-defined ABA triblock copolymers of poly(methyl acrylate)-polystyrene-poly(methyl acrylate) (PMA- b-PS- b-PMA) with different molecular weights were synthesized using Cl-PS-Cl as macroinitiator, CuCl/ N, N, N′, N″, N″-pentamethyldiethylenetriamine (PMDETA) as catalyst system via atom transfer radical polymerization (ATRP). Amphiphilic triblock copolymer poly(potassium acrylate)-polystyrene-poly(potassium acrylate) (PKAA- b-PS- b-PKAA) was obtained by hydrolyzing PMA- b-PS- b-PMA. The self-assembly behavior of the triblock copolymers in organic solutions, which is a good solvent for the PS block and in aqueous solutions, which is a good solvent for the PKAA blocks was studied by high performance particle sizer (HPPS). The results showed that the Z-average size of the micelles obviously increases with increase in molecular weight of triblock copolymers, and the micelles in organic solutions are relatively more stable than in aqueous solutions. The effect of the length of PS block on the Z-average size of the micelles is more obvious in organic solution than in aqueous solution. The morphology of triblock copolymers PKAA- b-PS- b-PKAA in aqueous solution, which is a nearly ‘pearl-necklace’-like shape, was examined by transmission electron microscopy (TEM) at room temperature.

Synthesis of superabsorbent resin by ultraviolet photopolymerization

AbstractSynthesis of superabsorbent resin (SAR) was achieved by a new method, that of direct UV photopolymerization, and in particular the synthesis of a SAR of acrylic acid–potassium acrylate copolymer by UV photopolymerization was investigated. Influences of ratio (mol) of acrylate monomer to acrylic acid monomer, photoinitiators, crosslinking agents, and exposure time of UV light on the water‐absorbent properties were investigated. The results showed that the water absorbency (Q) of SAR based on Irgacure 1700 or Irgacure 1800 was 545–530 mL/g, but under the same conditions Q was 450 mL/g for the SAR based on Irgacure 651. N,N′‐Methylene bisacrylamide, hydroethyl acrylate, and glycerol were used as crosslinking agents, of which N,N′‐methylene bisacrylamide was the most effective. It crosslinked the molecular chains through attending the copolymerization with acrylic acid (AA) and potassium acrylate. When the exposure time was 5 min, the value of Q was 1368 mL/g (the content of N,N′‐methylene bisacrylamide was 100 ppm). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1618–1624, 2004

Synthesis of superabsorbent copolymers as water manageable materials

AbstractStrongly water‐absorbing polymers based on the monomers acrylamide, potassium acrylate and magnesium methacrylate were prepared by copolymerization using ammonium persulfate as initiator and N,N‐methylene‐bisacrylamide (MBA) as crosslinking agent. The copolymers are synthesized by varying monomer, crosslinker and initiator concentrations. The experimental results shows that superabsorbents (SAPs) have good absorbency both in water and NaCl solutions. The copolymers are characterized by IR spectroscopy. Water retention in soil is enhanced by use of these superabsorbents. The SAPs use for the growth of sunflower plants is also investigated. The water retention capacity of the SAPs was carried out at 60 °C and 100 °C. Copyright © 2003 Society of Chemical Industry

Synthesis of superabsorbent starch‐graft‐poly(potassium acrylate‐co‐acrylamide) and its properties

AbstractThe superabsorbent's ability to resist deformation and to resist deswelling under externally applied pressures is important in practical application. For instance, it is used in infant diapers, in soil for agriculture, and in forestry. In this article, we report on the synthesis of a superabsorbent/starch‐graft‐poly(potassium acrylate‐co‐acrylamide) by inverse suspension polymerization. The effects of reaction conditions, such as monomeric concentration, ratio of water to oil, reaction temperature, and obtaining spherical resin, were investigated. Experiments showed that the superabsorbent has a good compressive strength and keeps the shape of particles after absorbing water. After mixing with soil it does not become sticky, and the loose structure can better retain air. It is fit to retain water in soil. In addition, thermogravimetric analysis revealed the superior thermal stability of the grafted product and its large particle size also reduces risk of air pollution. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1536–1542, 2003

Synthesis and Water Absorbency of Superabsorbent Copolymers

Superabsorbent copolymers (SAPs) based on the monomers acrylamide, calcium acrylate, and potassium acrylate were prepared by copolymerization using ammonium persulfate (APS) as initiator and N , N '-methylene-bis-acrylamide (MBA) as cross-linking agent. The copolymers were synthesized by varying monomer, cross-linker, and initiator concentrations. The experimental results show that SAPs have good absorbency both in water and NaCl solutions. The copolymers were characterized by IR spectroscopy. The water retention capacity of the SAPs was carried out at 60 and 100C.

Synthesis and swelling properties of superabsorbent copolymers

AbstractSuperabsorbent copolymers (SAPs) based on monomers acrylamide (AM), sodium acrylate (SA), and potassium acrylate (KA) were prepared by aqueous solution polymerization using ammonium persulfate (APS) as an initiator and N,N‐methylene‐bis‐acrylamide (MBA) as a cross‐linking agent. The copolymers were synthesized by varying, the monomer concentration, MBA concentration, and initiator concentration. The experimental results show the SAPs have better absorbency both in water and NaCl solutions. The copolymers are characterized by IR spectroscopy. The water retention in the soil is enhanced using the SAPs. The SAPs are tested for the growth of cosmos bipinnata plants and the results are presented. SAPs can be used as water management materials for agricultural and horticultural purpose in desert and drought prone areas. © 2001 John Wiley & Sons, Inc. Adv Polym Techn 20: 146–154, 2001

Elimination of suspended materials in contaminated effluents from cardboard recycling plants

The wastewater, from a paper plant whose raw material is recycled cardboard, was treated with different types of polyelectrolytes as coagulation‐flocculation agents, to reduce contamination levels as measured by the paramètres turbidity, suspended solids (SS) and chemical oxygen demand (COD). Different anionic polyelectrolytes were tested, including polyacrylamide in emulsion and potassium acrylate silicate ester, as well as different cationic polyelectrolites such as combinations of cationic polyacrylamide of various molecular weights with quaternary ammonium compounds in various ratios; polyacrylamides in emulsion; and quaternary ammonium compounds, including the EPI chlorhydrin dimethylamine. The investigation was carried out following a complete factorial experimental design with three variables at two levels (23). The polyelectrolyte concentration was the most important variable in the process for eliminating suspended particles. Therefore the results obtained with each coagulation‐flocculation agent were evaluated in terms of the polyelectrolyte concentration parameter.