pH-responsive carboxymethylcellulose-g-poly(sodium acrylate)/polyvinylpyrrolidone semi-IPN hydrogels with enhanced responsive and swelling properties

Abstract

Novel pH-responsive semi-interpenetrated polymer network (semi-IPN) superabsorbent hydrogels were prepared by the radical graft polymerization of carboxymethylcellulose (CMC) and partially neutralized acrylic acid (NaA) in the presence of a crosslinker, N,N'-methylene-bis-acrylamide (MBA), and linear polyvinylpyrrolidone (PVP). FTIR spectroscopy showed that NaA was grafted onto the CMC backbone and PVP combined with CMCg-PNaA network by hydrogen-bonding interaction. SEM showed that the formation of a semi-IPN structure improved the surface structure of the hydrogels. The reaction variables, including the mass ratio of acrylic acid (AA) to CMC, MBA concentration and PVP content were optimized, and the crosslinking density of the hydrogels was determined. In addition, the pH-response, swelling behavior of the hydrogel in various saline solutions and aqueous cetyltrimethylammonium bromide (CTAB) solutions were investigated. The results showed that the introduction of CMC and PVP clearly enhanced the swelling capability and rate, and improved the pH-responsive and On-Off switching swelling abilities, salt-resistance, and intriguing time-dependent swelling characteristics.

Enhanced Absorbent Products Incorporating Cellulose and Its Derivatives: A Review

“…Third, in the case of SAPs, addition of cationic surfactant has been shown to result in a marked decrease of absorbency Wang et al 2011c). Such an effect is consistent not only with the partially hydrophobic nature of the surfactants employed, but also with the expected electrostatic interactions.…”

“…Considerable research has been devoted to the development of copolymers in which CMC is reacted with acrylic monomers and various crosslinking agents to form SAPs (Kuwabara and Kubota 1996;Pourjavadi and Mahdavinia 2005;Pourjavadi and Ghasemzadeh 2006;Abd El-Mohdy 2007;Ibrahim et al 2007;Pourjavadi et al 2007aPourjavadi et al -b, 2008Pourjavadi et al , 2009Pourjavadi et al , 2010Suo et al 2007;Ali et al 2008;Chen et al 2008;Yang et al 2009;El-Din et al 2010;Feng et al 2010a;Lin et al 2010;Bao et al 2011;Eldin et al 2011;Huang et al 2011;Liu et al 2011;Shu et al 2011;Varaprasad et al 2011;Wang et al 2011c). Water absorbency values generally in the range of 40 to 1400 g/g have been reported in such studies, with the highest value reported by Pourjavadi et al (2008).…”

“…Related numerical simulation work has been reported (Masoodi et al 2012). The following articles have considered rates of absorption in the case of hydrogels (Kabra and Gehrke 1994;Zohariaan-Mehr et al 2010;Wang et al 2011c). Finally, Berg and coauthors have considered the rates of wicking into structures that are contained by fibers and hydrogel materials (Schuchardt and Berg 1991;Wiryana and Berg 1991).…”

Preparation and characterization of a novel pH-sensitive Salecan-g-poly(acrylic acid) hydrogel for controlled release of doxorubicin

“…During the polymerization, the AA monomer molecules, close to these active radical sites, became acceptors of Salecan radicals, leading to chain initiation and thereaer they became free radical donors to neighboring molecules, which caused the gra chain to grow. 46,47 In the course of the chain propagation, the end vinyl groups of the crosslinker BAAm could react synchronously with the polymer chains, thus, the copolymer hydrogel was comprised of a crosslinked structure and a network structure formed gradually.…”

Fabrication and properties of a novel superabsorbent composite based on coco peat and poly (acrylic acid) cross-linked trimethylolpropane trimaleate under ultraviolet irradiation

“…In particular, a lot of superabsorbent hydrogel composites based on the natural material substrate have been used in modern agriculture for the enhancement of both nutrition and water status of plants. For instance, starch, chitosan, cellulose, alginate, gumghatti, and guar gum have been concerned to the preparation of superabsorbent hydrogel composites for promising applications, because of their affordability, non‐toxicity, and accessibility. It has been verified that superabsorbent composites can be remarkably effective in increasing water holding capacity, decreasing deep percolation, and reducing evaporation losses in sandy soils …”