Graft copolymerization onto starch. II. Grafting of acrylic acid and preparation of it's hydrogels

Athawale, Vilas D.; Lele, Vidyagauri

doi:10.1016/s0144-8617(97)00138-0

Cited by 222 publications

(107 citation statements)

References 13 publications

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“…Such behaviors are reported by other investigators. [22][23][24] Effect of APS Concentration 7 7 The relationship between the initiator concentration and water absorbency values was studied by varying the APS concentration from 0.09 to 0.35 mol/L ( Figure 5). According to Figure 5, the absorbency is increased with increasing the APS concentration from 0.09 up to 0.22 mol/L and then, it is decreased considerably with a further increase in the amount of monomer.…”

Section: Resultsmentioning

confidence: 99%

Partially hydrolyzed crosslinked alginate-graft-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive Properties

2005

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In this study, a series of highly swelling hydrogels based on sodium alginate (NaAlg) and polymethacrylamide (PMAM) was prepared through free radical polymerization. The graft copolymerization reaction was performed in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylenebisacrylamide (MBA) as a crosslinker. The crosslinked graft copolymer, alginate-graft-polymethacrylamide (Alg-g-PMAM), was then partially hydrolyzed by NaOH solution to yield a hydrogel, hydrolyzed alginate-graft-polymethacrylamide (H-Alg-g-PMAM). During alkaline hydrolysis, the carboxamide groups of Alg-g-PMAM were converted into hydrophilic carboxylate anions. Either the Alg-g-PMAM or the H-Alg-g-PMAM was characterized by FTIR spectroscopy. The effects of the grafting variables (i.e., concentration of MBA, MAM, and APS) and the alkaline hydrolysis conditions (i.e., NaOH concentration, hydrolysis time, and temperature) were optimized systematically to achieve a hydrogel having the maximum swelling capacity. Measurements of the absorbency in various aqueous salt solutions indicated that the swelling capacity decreased upon increasing the ionic strength of the swelling medium. This behavior could be attributed to a charge screening effect for monovalent cations, as well as ionic crosslinking for multivalent cations. Because of the high swelling capacity in salt solutions, however, the hydrogels might be considered as anti-salt superabsorbents. The swelling behavior of the superabsorbing hydrogels was also measured in solutions having values of pH ranging from 1 to 13. Furthermore, the pH reversibility and on/off switching behavior, measured at pH 2.0 and 8.0, suggested that the synthesized hydrogels were excellent candidates for the controlled delivery of bioactive agents. Finally, we performed preliminary investigations of the swelling kinetics of the synthesized hydrogels at various particle sizes.

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Section: Resultsmentioning

confidence: 99%

Partially hydrolyzed crosslinked alginate-graft-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive Properties

2005

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“…Results from starch-based hydrogels show a wide range of maximal absorption capacities, but they are usually lower than for fully synthetic materials. For example, acrylic acidgrafted starch using ceric ammonium nitrate initiator as made by Masuda et al (1978) and Athawale and Lele (1998) shows WAC values of ca 200 g/g. But initiation by irradiation with ␥-rays as applied by Kiatkamjornwong et al (2002) shows an enhanced maximum water absorbency of up to 469 g/g.…”

Section: Effect Of the Amount Of Crosslinker Addedmentioning

confidence: 99%

Water absorption, retention and the swelling characteristics of cassava starch grafted with polyacrylic acid

Witono

Noordergraaf

Heeres

et al. 2014

Carbohydrate Polymers

171

103

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“…The percentage grafting efficiency (GE%) and percentage of add-on (add-on%) were calculated [31] as follows:…”

Section: Preparation Of Chitosan-graft-itaconic Acid and Chitosan-gramentioning

confidence: 99%

Adsorption of Brilliant Green from Aqueous Solutions onto Crosslinked Chitosan Graft Copolymers

Özkahraman

Bal

Acar

et al. 2011

CLEAN Soil Air Water

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In this study, graft copolymerization of itaconic acid (IA) and crotonic acid (CA) onto the crosslinked chitosan beads were carried out using ammonium persulfate as initiator. Grafted chitosan beads were characterized by FT-IR analysis and grafting percentage determination. Grafting efficiency and add-on percentages values of grafted chitosan beads were determined as 23-29 and 32-47%, respectively. Then, equilibrium isotherms and kinetics of brilliant green adsorption onto grafted chitosan beads were investigated. The results indicated that the pseudo-second-order kinetic model fitted better than the data obtained from pseudo-first-order model for the adsorption of brilliant green onto grafted chitosan beads. The fit of data for brilliant green (BG) adsorption onto grafted chitosan beads suggested that the Langmuir model gave closer fittings than the Freundlich model.

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Graft copolymerization onto starch. II. Grafting of acrylic acid and preparation of it's hydrogels

Cited by 222 publications

References 13 publications

Partially hydrolyzed crosslinked alginate-graft-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive Properties

Partially hydrolyzed crosslinked alginate-graft-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive Properties

Water absorption, retention and the swelling characteristics of cassava starch grafted with polyacrylic acid

Adsorption of Brilliant Green from Aqueous Solutions onto Crosslinked Chitosan Graft Copolymers

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