Swelling behavior of gelatin-ionic liquid functional polymers

In this work, hydrogels obtained by mixing gelatin with ionic liquids (ILs) are prepared. Two different ILs, [emim][EtSO4] and [bmim][N(CN)2], are used to prepare hydrogels with different amounts of starting water and phosphate buffer content, which are used after a maturation period. The percentage of swelling in water and phosphate buffer, swelling and diffusion parameters are investigated in thin-film polymers (1 x 1 cm2; 1-mm thick) with different maturation times and at temperatures ranging from 4 to 37 degrees C. [emim][EtSO4] polymers show a moderate (100% weight increase) but quick swelling that reaches 80% of the equilibrium within 30 min. They are liquefied and dissolved at temperatures above 25 degrees C. [bmim][N(CN)2] polymers with short maturation times exhibit a similar behavior to the former, but more mature hydrogels register a very small swelling, abnormal kinetics and are more resistant to higher temperatures. (c) 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys., 2013, 51, 817-825