Study of the effect of reaction variables on grafting of polyacrylamide onto chitosan

Yazdani‐Pedram, Mehrdad; Lagos, A.; Retuert, P.J.

doi:10.1007/s00289-002-0006-2

Cited by 44 publications

(31 citation statements)

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“…Conventional methods for measuring the grafting ratio, such as weighing, [20][21][22] spectroscopy, 23,24 and the elemental analysis method, 25 all had their own limitations in practical application. The weighing method for measuring the grafting ratio was based on the mass increment of the final product compared with the weight of the backbone polymer.…”

Section: Determination Of the Grafting Ratio Of The Graft Copolymers mentioning

confidence: 99%

The flocculating properties of chitosan‐graft‐polyacrylamide flocculants (I)—effect of the grafting ratio

Yuan

Shang²,

et al. 2010

J of Applied Polymer Sci

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A series of chitosan-graft-polyacrylamide copolymers have been prepared as flocculants for waste water treatment. The results indicated that the grafting ratio was one of the key factors for the flocculating effects. The copolymers with various grafting ratios showed different flocculating properties. To observe every detail of this effect, the specific refractive index increment measurement (SRIIM) method was used to determine the grafting ratio at the beginning of this study. Interestingly, it was found that as the grafting ratio increased, the flocculating effect increased until it reached its maximum point. At that point, it decreased. This result was discussed in terms of the cooperative effects of the charge neutralization and bridging flocculating mechanisms. A structure model of chitosan-g-polyacrylamide copolymer flocculants has been proposed.

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Section: Determination Of the Grafting Ratio Of The Graft Copolymers mentioning

confidence: 99%

The flocculating properties of chitosan‐graft‐polyacrylamide flocculants (I)—effect of the grafting ratio

Yuan

Shang²,

et al. 2010

J of Applied Polymer Sci

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“…Because of the properties of chitosan and polyacrylamide, several works have explored the feasibility of a polyacrylamide/chitosan blend. These studies have reported different aspects of the characterization, biocompatibility, and release properties of polyacrylamide/chitosan hydrogels [25][26][27]. Synthesis method, swelling kinetics, and Young's moduli for a polyacrylamide/chitosan hybrid polymeric network at various chitosan concentrations, and different swelling media are reported in this work.…”

Section: Introductionmentioning

confidence: 95%

Swelling characterization and drug delivery kinetics of polyacrylamide-co-itaconic acid/chitosan hydrogels

Martínez-Ruvalcaba¹,

Sánchez-Díaz²,

Becerra³

et al. 2009

Express Polym. Lett.

116

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Abstract. Hybrid polymeric networks composed of polyacrylamide and chitosan were developed to determine their swelling and ascorbic acid delivery kinetics at various chitosan concentrations. The hybrid acrylamide/chitosan hydrogels were synthesized in aqueous itaconic acid solution (1% w/w). Young's modulus was also evaluated for the hydrogels, and the results were correlated with the swelling properties. Swelling experiments were carried out using three different pH solutions: acidic (pH 4 buffer solution), neutral (distilled water) and basic (pH 10 buffer solution). The results of the swelling study showed that the swelling properties of the network varied with the changes of the pH in the swelling solution, as well as concentration of chitosan. When chitosan concentration increased, the swelling capacity diminished, and therefore Young's modulus increased. The results indicated that the swelling process followed a second order kinetics. The ascorbic acid diffusion inside the hydrogel follows a Fickian mechanism. The ascorbic acid diffusion coefficients are reported as a function of chitosan concentration.

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“…[18] The spectra of grafted chitosan samples were taken by using a Bruker IFS-28 instrument. The samples were prepared as KBr pellets.…”

Section: Characterizationmentioning

confidence: 99%

“…[18][19][20] Different grafting percentages (%G) of PAAM on CHI were obtained by varying reaction parameters such as temperature, solvent volume, and relative concentrations of monomer, crosslinking agent, and initiator. [18] The grafting extent was estimated by considering the increase in weight of the original CHI and the weight of CHI after grafting and purification by extraction. Grafted CHI was extracted with water in order to remove any PAAM homopolymer that could form during the grafting process.…”

Section: Grafting Reactionsmentioning

confidence: 99%

Synthesis and Unusual Swelling Behavior of Combined Cationic/Non‐Ionic Hydrogels Based on Chitosan

Yazdani‐Pedram

Tapia

Retuert

et al. 2003

Macromolecular Bioscience

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Hydrogel‐forming copolymers based on chitosan grafted with different amounts of polyacrylamide were synthesized and its swelling capacity determined in distilled water, sodium chloride solutions, as well as in buffer solutions at pH 1.2 and 8.0. The resulting products are highly efficient as hydrogel‐forming materials with swelling at equilibrium going approximately from 300 to 3 000 times the volume of the dry solid polymer in all the investigated media. The products, different to usual hydrogels, swells considerably more and quickly in electrolyte‐containing solutions compared to in distilled water. This has been attributed to their structure that contains non‐ionic polyacrylamide macromolecules grafted onto the trunk polymer chitosan, which is cationic in nature. In‐vitro drug‐release behavior of formulations containing grafted copolymers have been tested using theophylline as a water‐soluble drug and the results were compared with similar formulations containing unmodified chitosan. It was found that tablets based on formulations containing grafted chitosan show higher erosion and swelling compared with those of the matrix based on unmodified chitosan, leading to a higher fraction of theophylline released. It can be concluded that formulations based on the synthesized copolymers are potentially useful for fluid absorbency and as prolonged drug‐release matrices.The swelling of one of the hydrogels studied here.magnified imageThe swelling of one of the hydrogels studied here.

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Study of the effect of reaction variables on grafting of polyacrylamide onto chitosan

Cited by 44 publications

References 0 publications

The flocculating properties of chitosan‐graft‐polyacrylamide flocculants (I)—effect of the grafting ratio

The flocculating properties of chitosan‐graft‐polyacrylamide flocculants (I)—effect of the grafting ratio

Swelling characterization and drug delivery kinetics of polyacrylamide-co-itaconic acid/chitosan hydrogels

Synthesis and Unusual Swelling Behavior of Combined Cationic/Non‐Ionic Hydrogels Based on Chitosan

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