Hydroxyl radical-induced crosslinking and radiation-initiated hydrogel formation in dilute aqueous solutions of carboxymethylcellulose

Wach, Radosław A.; Rokita, Bożena; Bartoszek, Nina; Katsumura, Yosuke; Ulański, Piotr; Rosiak, Janusz M.

doi:10.1016/j.carbpol.2014.06.007

Cited by 39 publications

(17 citation statements)

References 27 publications

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“…Radiation-initiated crosslinking was supposed to require high solute concentrations, as in dilute solutions the chain degradation processes are dominant [19]. However, recently gels were successfully synthesized from low concentration solutions at low pH, as well [21]. The swelling of the superabsorbents is usually sensitive to different environmental conditions, such as the temperature, pH, type of salt or ionic strength of the swelling solution [22, 23].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of carboxymethylcellulose/starch superabsorbent hydrogels by gamma-irradiation

Fekete

Borsa

Takács

et al. 2017

Chemistry Central Journal

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Background: Superabsorbent hydrogels show a large potential in a wide array of applications due to their unique properties. Carboxymethylcellulose (CMC) is a commercially available water-soluble cellulose derivative of major interest in the hydrogel synthesis. High-energy irradiation allows the chemical crosslinking without the use of crosslinking agents, while the introduction of other natural or synthetic polymers offers a convenient way to modify the gels. In this study we examined the effect of the addition of starch, a low-cost renewable polysaccharide, on the properties of carboxymethylcellulose-based hydrogels.Results: Superabsorbent gels were prepared by gamma irradiation from aqueous mixtures of carboxymethylcellulose and starch. The partial replacement of CMC with starch improved the gel fraction, while a slight increase in the water uptake was also observed. However, very high starch content had a negative impact on the gelation, resulting in a decrease in gel fraction. Moreover, higher solute concentrations were preferred for the gelation of CMC/starch than for pure CMC. Hydrogels containing 30% starch showed the best properties: a water uptake of ~350 g water /g gel was achieved with ~55% gel fraction synthesized from 15 w/w% solutions at 20 kGy. Heterogeneous gel structure was observed: the starch granules and fragments were dispersed in the CMC matrix. The swelling of CMC/starch gels showed a high sensitivity to the ionic strength in water due to the CMC component. However, the mixed gels are less sensitive to the ionic strength than pure CMC gels.

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Section: Introductionmentioning

confidence: 99%

Synthesis of carboxymethylcellulose/starch superabsorbent hydrogels by gamma-irradiation

Fekete

Borsa

Takács

et al. 2017

Chemistry Central Journal

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“…Radicals formed on the polymer chains during irradiation may initiate crosslinking or degradation (Charlesby 1955). Crosslinking is usually observed at higher solute concentrations (Fei et al 2000;Yoshii et al 2003), but recently successful gel formation in dilute solutions was also reported (Wach et al 2014). Of the cellulose derivatives, most of the publications appear on the radiation induced synthesis of carboxymethylcellulose hydrogels (El-Din et al 2010;Fei et al 2000;Liu et al 2002;Wach et al 2003a), other derivatives getting significantly less attention (Furusawa et al 2005;Pekel et al 2004;Wach et al 2003b).…”

Section: Introductionmentioning

confidence: 99%

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

et al. 2014

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Hydrogels with high water uptake were prepared by ionizing radiation induced crosslinking in aqueous solutions of four cellulose derivatives (carboxymethylcellulose sodium salt-CMC-Na, methylcellulose-MC, hydroxyethylcellulose-HEC and hydroxypropylcellulose-HPC). The gel fraction increased with absorbed dose, while water uptake decreased. At high polymer concentrations lower gel fractions were found due to the lower polymer chain mobility and inhomogeneity at low water content. The swelling rate gradually slowed down after 4-5 h. CMC and HEC gels reached equilibrium after 24 h, while HPC and MC gels required longer immersion times. Gels showed second-order swelling kinetics in water. The mechanism of the water diffusion proved to be anomalous. In pure water, CMC gels showed the highest, while HPC and MC gels the lowest water uptake. The derivatives had different sensitivities to ionic strength in the swelling solution. The salt type also proved to be a significant factor at uniform ionic strength. Thus different cellulose derivative based gels may be preferred at various applications depending on the environment.

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“…Other than concentration of polymers, irradiation dose is also important in determining the degree of crosslinking because too low irradiation dose will cause less crosslink due to low radiation energy whereas too high irradiation dose will cause more scission and oxidative degradation of polymers. Hence, in order to obtain the highest gel fraction, it is important to determine the appropriate irradiation doses that allow crosslinking to occur predominant over scission …”

Section: Resultsmentioning

confidence: 99%

Dual crosslinked carboxymethyl sago pulp/pectin hydrogel beads as potential carrier for colon‐targeted drug delivery

Tan

Wong

et al. 2016

J of Applied Polymer Sci

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Carboxymethyl sago pulp (CMSP)/pectin hydrogel beads were synthesized by calcium crosslinking and further crosslinked by electron beam irradiation to form drug carrier for colon-targeted drug. Sphere-shaped CMSP/pectin 15%/5% hydrogel beads is able to stay intact for 24 h in swelling medium at pH 7.4. It shows pH-sensitive behavior as the swelling degree increases as pH increases. Fourier transform infrared spectroscopy analysis confirmed the absence of chemical interaction between hydrogel beads and diclofenac sodium. Differential scanning calorimetric and X-ray diffraction studies indicate the amorphous nature of entrapped diclofenac sodium. The drug encapsulation efficiency is up to about 50%. Less than 9% of drug has been released at pH 1.2 and the hydrogel beads sustain the drug release at pH 7.4 over 30 h. This shows the potential of CMSP/pectin hydrogel beads as carrier for colon-targeted drug.

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Hydroxyl radical-induced crosslinking and radiation-initiated hydrogel formation in dilute aqueous solutions of carboxymethylcellulose

Cited by 39 publications

References 27 publications

Synthesis of carboxymethylcellulose/starch superabsorbent hydrogels by gamma-irradiation

Synthesis of carboxymethylcellulose/starch superabsorbent hydrogels by gamma-irradiation

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

Dual crosslinked carboxymethyl sago pulp/pectin hydrogel beads as potential carrier for colon‐targeted drug delivery

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