Hydrogels based on alkylated chitosan and polyelectrolyte copolymers

Hydrogels formed by alkylated chitosan with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride and synthetic copolymers forming polyelectrolyte complexes are presented. The copolymer polyelectrolytes were synthesized through free-radical polymerization. Their compositions and reactivity parameters were determined by the Finemann-Ross and Kelen-Tudos methods. The copolymers have structures that tend to be alternating. The hydrogels were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, scanning electron microscopy, and water solubility tests at different pH values. For the formation of the hydrogels, they were prepared using different molar ratios of alkylated chitosan and polyelectrolyte copolymers. Their stability was determined by rheological analysis, evaluating the response as a function of strain and frequency. The rheological tests showed that the stability of the polyelectrolyte complexes followed the trend ChT-CP2>ChT-CP3>ChT-CP1 due to the presence of greater electrostatic interactions. (C) 2018 Wiley Periodicals, Inc.