ABSTRACT Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-methylene bu-tane-1,4-dioic acid. Hydrogel swelling was measured as a function of the composition of the hydrogel and of the crosslinking agent ratio. High values of swelling have been obtained at very high crosslinking values (< 14 wt %) and the equilibrium swelling was reached at very low time (less than 15 minutes). The swelling isotherms consisted of a steep initial portion and then levelled off as asymptotically to the equilibrium swelling limit. The experimental data suggest clearly that the swelling process obeys second-order kinetics. According to this, the kinetics rate constant and the equilibrium water content were determined at different comonomer composition and crosslinker concentration. The calculated kinetic constants ranged from 0.48 to 3.76 × 10-2 min-1 for poly (acrylic acid-co-Q9) hydrogels and from 0.68 to 4.0 × 10-2 min-1 for poly (2-methylene butane-1,4-dioic acid-co-Q9) hydrogels depending on the hydrogels composition. The diffusion process was evaluated for each hydrogel showing a non-Fickian type diffusion. In all cases was observed a considerable increase in diffusion coefficient as Q9 content increases.
Cite this paper
nullI. Katime and E. Mendizábal, "Swelling Properties of New Hydrogels Based on the Dimethyl Amino Ethyl Acrylate Methyl Chloride Quaternary Salt with Acrylic Acid and 2-Methylene Butane-1,4-Dioic Acid Monomers in Aqueous Solutions," Materials Sciences and Applications, Vol. 1 No. 3, 2010, pp. 162-167. doi: 10.4236/msa.2010.13026.
 L. W. FU and S. Chich-Hsuan, “PH-Thermoreversible Hydrogels. II. Synthesis and Swelling Behaviors of N- Isopropylacrylamide-Co-Acrylic Acid-Co-Sodium Acry-late Hydrogels,” Journal of Applied Polymer Science, Vol. 73, No. 10, September 1999, pp. 1955-1967.
 I. P. Lee, “Kinetics of Drug Release from Hydrogel Ma-trices,” Journal of Controlled Release, Vol. 2, November 1985, pp. 277-288.
 I. Katime, R. Novoa and F. Zuluaga, “Swelling Kinetics and Release Studies of Theophylline and Aminophylline from Acrylic Acid/N-Alkyl Methacrylate Hydrogels,” European Polymer Journal, Vol. 37, No. 7, July 2001, pp. 1465-1471.
 A. Nagaoka, “Mechanical Properties of Composite Hy-drogels,” Polymer Journal, Vol. 21, No. 10, April 2005, pp. 847- 850.
 H. Schott, “Swelling Kinetics of Polymers,” Journal of Macromolecular Science, Vol. 31, No. 1, March 1992, pp. 1-9.
 N. M. Franson and N. A. Pepas, “Influence of Copolymer Composition on Non-Fickian Water Transport through Glassy Copolymers,” Journal of Applied Polymer Science, Vol. 28, No. 4, April 1983, pp. 1299-1310.
 I. Katime and E. Rodríguez, “Synthesis and Swelling Kinetics of Poly(Acrylic Acid-Co-Itaconic Acid) Hydro-gels,” Recent Research Developments in Polymer Science, Vol. 5, 2001, pp. 139-152.
 P. E. M. Allen, D. J. Bennette and D. R. G. Williams, “Water in Methacrylates—I. Sorption and Desorption Properties of Poly(2-Hydroxyethyl Methacrylate-Co-Glycol Dimethacrylate) Networks,” European Polymer Journal, Vol. 28, No. 4, April 1992, pp. 347-352.
 C. S. Brazel and N. A. Pepas, “Mechanisms of solute and Drug Transport in Relaxing, Swellable, Hydrophilic Glassy Polymers,” Polymer, Vol. 40, No. 12, June 1999, pp. 3383-3398
 I. Katime, N. Valderruten and J. R. Quintana, “Controlled Release of Aminophylline from Poly (N-Isopropylacrylamide- Co-Itaconic Acid) Hydrogels,” Polymer International, Vol. 50, No. 8, August 2001, pp. 869-879.
 A. R. Berens and H. B. Hopfenberg, “Diffusion and Re-laxation in Glassy Polymer Powders: 2. Separation of Diffusion and Relaxation Parameters,” Polymer, Vol. 19, No. 5, May 1978, pp. 489-496.
 H. L. Frisch, “Sorption and Transport in Glassy Poly-mers—A Review,” Polymer Engineering & Science, Vol. 20, No. 1, January 1980, pp. 2-13.
 J. Crank “The Mathematics of Diffusion,” Clarendon Press, Oxford, 1975.
 I. Katime, R. Novoa, E. Díaz de Apodaca, E. Mendizábal and J. E. Puig, “Theophylline Release from Poly(Acrylic Acid-Co-Acrylamide) Hydrogels,” Polymer Testing, Vol. 18, No. 7, October 1999, pp. 559-566.