Novel cation-exchange composites resulting from polymerization / cross-linking of acrylic acid / N-methylolacrylamide mixtures with cellulose

The synthesis and characterization of a series of injectable and stimuli responsive hydrogels based on polyacryloyl hydrazide have been accomplished using dimethyl 2,2′-thiodiacetate, acrylic acid, diethyl malonate and polyethylene glycol diacrylate as cross-linkers through a chemical or dual cross-linking pathway.

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pH-sensitive polyvinylpyrrolidone-acrylic acid hydrogels: Impact of material parameters on swelling and drug release

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502011000100018 ◽

2014 ◽

Vol 50 (1) ◽

pp. 173-184 ◽

Cited By ~ 32

Author(s):

Kashif Sohail ◽

Ikram Ullah Khan ◽

Yasser Shahzad ◽

Talib Hussain ◽

Nazar Muhammad Ranjha

Keyword(s):

Drug Release ◽

Acrylic Acid ◽

Phosphate Buffer ◽

Ph Sensitive ◽

Cross Linking ◽

Release Mechanism ◽

Effect Analysis ◽

X Ray Crystallography ◽

Buffer Solutions ◽

The One

In this study, we fabricated pH-sensitive polyvinylpyrrolidone/acrylic acid (PVP/AA) hydrogels by a free-radical polymerisation method with variation in the content of monomer, polymer and cross-linking agent. Swelling was performed in USP phosphate buffer solutions of pH 1.2, 5.5, 6.5 and 7.5 with constant ionic strength. Network structure was evaluated by different parameters and FTIR confirmed the formation of cross-linked hydrogels. X-ray crystallography showed molecular dispersion of tramadol HCl. A drug release study was carried out in phosphate buffer solutions of pH 1.2, 5.5 and 7.5 for selected samples. It was observed that swelling and drug release from hydrogels can be modified by changing composition and degree of cross-linking of the hydrogels under investigation. Swelling coefficient was high at higher pH values except for the one containing high PVP content. Drug release increased by increasing the pH of the medium and AA contents in hydrogels while increasing the concentration of cross-linking agent had the opposite effect. Analysis of the drug release mechanism revealed non-Fickian transport of tramadol from the hydrogels.

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Preparation of Cation Exchange Fiber by Preradiation-Induced Grafting of Acrylic Acid without Removal of the Inhibitor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.150-151.1764 ◽

2010 ◽

Vol 150-151 ◽

pp. 1764-1767 ◽

Cited By ~ 1

Author(s):

Jun Fu Wei ◽

Kong Yin Zhao ◽

Huan Zhang ◽

Xiao Lei Wang ◽

Li Chen

Keyword(s):

Acrylic Acid ◽

Cation Exchange ◽

Storage Time ◽

Monomer Concentration ◽

Weak Acid ◽

Polymerization Inhibitor ◽

Acid Cation ◽

Radiation Induced ◽

Γ Ray ◽

Radiation Induced Grafting

A weak acid cation exchange fiber was prepared by γ-ray pre-radiation induced grafting of acrylic acid (AA) onto polypropylene (PP) non-woven without removal of the polymerization inhibitor in acrylic acid. The factors influenced the grafting degree were discussed, such as radiation dose, initiator concentration, monomer concentration, storage time and bath ratio. It is found that the initiator 2, 2'-Azobisisobutyronitrile (AIBN) was necessary for the increased grafting of AA without removing the inhibitor in AA.

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Comparison of Cation Exchange in Ganophyllite and [Na + Al]-Substituted Tobermorite: Crystal-Chemical Implications

Mineralogical Magazine ◽

10.1180/minmag.1988.052.366.08 ◽

1988 ◽

Vol 52 (366) ◽

pp. 371-375 ◽

Cited By ~ 8

Author(s):

Sridhar Komarneni ◽

Stephen Guggenheim

Keyword(s):

Cation Exchange ◽

Exchangeable Cations ◽

Cross Linking ◽

Crystal Chemical ◽

Layer Silicates ◽

Residual Charge ◽

Interlayer Region ◽

Exchange Properties ◽

Charge Configuration

AbstractGanophyllite and [Na+ + Al3+]-substituted tobermorite exhibited similar cation exchange properties and, in particular, selective cesium exchange. [Na+ + Al3+]-substituted tobermorite and ganophyllite showed a selective Cs exchange of 10.77 and 8.71 meq/100 g from 0.02N NaCl and of 11.08 and 9.04 meq/100 g from 0.02N CaCl2, respectively. The [Na+ + Al3+]-substituted tobermorite is structurally similar to ganophyllite: both are roughly analogous to 2:1 layer silicates, both have cross-linking tetrahedra across the interlayer region, and both have exchangeable cations located in zeolite-like sites in the interlayer region. The similarities in cation exchange properties imply that the residual charge configuration of the analogue 2 : 1 layer must be approximately equivalent also.

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Synthesis and characterization of thermoresponsive hydrogels cross-linked with chitosan

Open Chemistry ◽

10.2478/s11532-007-0065-1 ◽

2008 ◽

Vol 6 (1) ◽

pp. 107-113 ◽

Cited By ~ 2

Author(s):

Yueqin Yu ◽

Xianzhi Chang ◽

Hansheng Ning ◽

Shusheng Zhang

Keyword(s):

Acrylic Acid ◽

Pure Water ◽

Solution Temperature ◽

Feed Ratio ◽

Cross Linking ◽

Environmentally Responsive ◽

Extracellular Materials ◽

Degradation Properties ◽

Phosphate Buffered Saline

AbstractHydrogels composed of N-isopropylacrylamide (NIPAAm) and acrylic acid (AAc) were prepared by redox polymerization with degradable chitosan cross-linkers. Chitosan degradable cross-linkers were synthesized by the acrylation of the amine groups of glucosamine units within chitosan and characterized with 1H NMR. With the chitosan cross-linkers, loosely cross-linked poly(N-isopropylacryamideco-acrylic acid) [P(NIPAAm-co-AAc)] hydrogels were prepared, and their phase transition behavior, lower critical solution temperature (LCST), water content and degradation properties were investigated. The chitosan cross-linked P(NIPAAm-co-AAc) hydrogels were pliable and transparent at room temperature. The LCST could be adjusted at 32∼39°C by alternating the feed ratio. Swelling was influenced by NIPAAm/AAc monomer ratio, cross-linking density, swelling media, and temperature. All hydrogels with different feeding ratios contained more than 95% water at 25°C in the ultra pure water and phosphate-buffered saline (PBS, pH = 7.4 ± 0.1), and had a prospective swelling in the simulated gastric fluids (SGF, pH = 1.2) > 72.54%. In degradation studies, breakdown of the chitosan cross-linked P(NIPAAm-co-AAc) hydrogels was dependent on the cross-linking density. The chitosan cross-linked P(NIPAAm-co-AAc) hydrogels which can be tailored to create environmentally-responsive artificial extracellular materials have great potential for future use.

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Synthesis and Properties of Thermo- and pH-Sensitive Poly[(Sodium Humate)-(N-Isopropylacrylamide)-(Acrylic Acid)] Intelligent Hydrogel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.781-784.536 ◽

2013 ◽

Vol 781-784 ◽

pp. 536-541

Author(s):

Xiao Mi Zhou ◽

Xiao Ran Sun ◽

Guang Yue Li

Keyword(s):

Acrylic Acid ◽

Suspension Polymerization ◽

Ammonium Persulfate ◽

Continuous Phase ◽

Ph Sensitive ◽

Cross Linking ◽

Swelling Ratio ◽

Inverse Suspension Polymerization ◽

Sensitive Characteristics ◽

Intelligent Hydrogel

A novel intelligent hydrogel of poly(Humic acid - Nisopropylacrylamide - Acrylic acid) (P(NIPAAm-HA-AA)) was prepared at 70°C by inverse suspension polymerization. The reactions include uses N,N-methylene-bis-acrylamide (MBA) as a cross-linking agent, ammonium persulfate (KPS) as an initiator, cyclohexane as a continuous phase and span-65 as dispersant. The influence such as concentration of monomers and cross-linking agent, mole fraction of span-65 in mixed monomers, and temperature of polymerization on the property of resulting P(NIPAAm-HA-AA) hydrogels was investigated in detail. Fourier transform infrared (FTIR) demonstrated that NIPAAm, HA and AA was synthetized successfully. The results showed that the swelling ratio (SR) of modified hydrogel was improved significantly with the dosage of NIPAAm. It was also observed that the thermosensitive and pH sensitive characteristics was strongly affected by concentrations of NIPAAm. At last, we choose NIPAAm: HA=0.3.

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