Thermoresponsive super water absorbent hydrogels prepared by frontal polymerization of N‐isopropyl acrylamide and 3‐sulfopropyl acrylate potassium salt |
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| Authors: | Sergio Scognamillo Valeria Alzari Daniele Nuvoli Javier Illescas Salvatore Marceddu Alberto Mariani |
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| Affiliation: | 1. Dipartimento di Chimica, Università degli Studi di Sassari, and local INSTM Unit, Via Vienna 2, 07100 Sassari, Italy;2. Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, C.P. 04510, México D.F.;3. Istituto di Scienze delle Produzioni Alimentari – Consiglio Nazionale delle Ricerche (ISPA‐CNR), Li Punti – Reg. Baldinca, Traversa La Crucca, Sassari 07100, Italy |
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| Abstract: | Super water absorbent polymer hydrogels were synthesized by frontal polymerization. These materials were obtained by copolymerizing N‐isopropyl acrylamide (NIPAAm) and 3‐sulfopropyl acrylate potassium salt (SPAK) in the presence of N,N′‐methylene‐bis‐acrylamide as a crosslinker. It was found that their swelling behavior in water can be easily tuned by using either the appropriate monomer ratio or the amount of the crosslinker used. Namely, the swelling ratio was found to range from about 1000% for the NIPAAm homopolymer in the presence of 5.0 mol % of crosslinker, up to 35,000% for the sample containing 87.5 mol % of SPAK and 1.0 mol % of crosslinker. The affinity toward water was also confirmed by contact angle analysis. Moreover, the obtained hydrogels exhibit a thermoresponsive behavior, with a lower critical solution temperature of about 28–30 °C. This value is close to that of poly(NIPAAm) but with a swelling capability that dramatically increases as the amount of SPAK increases. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 |
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| Keywords: | frontal polymerization hydrogels radical polymerization swelling thermoresponsive super water absorbent hydrogels |
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