A novel kappa-carrageenan (C)-based superabsorbing hydrogel was synthesized through graft copolymerization of acrylamide (AAm) onto a C substrate in the presence of a crosslinking agent. The crosslinked C-poly(AAm) polymer graft was partially hydrolyzed in alkaline medium to yield a superabsorbent resin, H-carragPAM. The resin structure was confirmed using FTIR spectroscopy. The variables of graft copolymerization (monomer, initiator, polysaccharide and crosslinker concentration, reaction temperature and time as well as stirrer speed) that affected on the ultimate water-swelling capacity were optimized. The time-temperature variation of the copolymerization was investigated in terms of the absence and presence of the atmospheric oxygen. Under optimized conditions, the maximum capacity of swelling in distilled water and saline (0.9wt% NaCl) were 1,465 and 121g/g, respectively. Since this hydrogel exhibited a very high absorptivity in saline, it may be referred to as low salt sensitive superabsorbent.
Kirk, R.E. and Othmer, D.F. (1992). Encyclopedia of Chemical Technology, Kroschwitz, J.I. and Howe-Grant, M. (eds), 4th edn, vol. 4, p. 942, John Wiley & Sons, New York .
2.
Usov, A.I. (1998). Structural Analysis of Red Seaweed Galactans of Agar and Carrageenan Groups , Food Hydrocoll., 12: 301-308 .
3.
Theerkeelsen, H.G. (1993). Carrageenan Chapter, Industrial Gums, Whistler, R.L. and BeMiller, J.N. (eds), Academic Press Inc., London .
4.
Sjoberg, H. , Persson, S. and Caram-Lelham, N. (1999). How Interactions Between Drugs and Agarose-Carrageenan Hydrogels Influence the Simultaneous Transport of Drugs , J. Contr. Rel., 59: 391-400 .
5.
Takemasa, M.Chiba, A. and Date, M. (2002). Counterion Dynamics of - and -Carrageenan Aqueous Solutions Investigated by the Dielectric Properties , Macromolecules, 35(14): 5595-5600 .
6.
Antonov, Y.A. and Goncalves, M.P. (1999). Phase Separation in Aqueous Gelatin-Carrageenan Systems , Food Hydrocoll., 13: 517-524 .
7.
Beaumont, M.D. and Knorr, D. (1987). Effects of Immobilizing Agents and Procedures on Viability of Cultured Celery (Apium Graveolens) Cells , Biotech. Lett., 9: 377-382 .
8.
Gupta, P. and Vermani, K. (2002). Hydrogels: From Controlled Release to pH-Responsive Drug Delivery , Drug Discovery Today, 7: 569-579 .
9.
Po, R. (1994). Water-absorbent Polymers, A Patent Survey , J. Macromol. Sci., Rev. Macromol. Chem. Phys., C34: 607-661 .
10.
Sugahara, Y. and Takahisa, O. (2001). Synthesis of Starch-Graft-Polyacrylonitrile Hydrolyzate and Its Characterization , J. Appl. Polym. Sci., 82: 1437-1443 .
11.
Patel, G.M. , Patel, C.P. and Trivedi, H.C. (1999). Ceric-Induced Grafting of Methyl Acrylate onto Sodium Salt of Partially Carboxymethylated Sodium Alginate , Eur. Polym. J., 35: 201-208 .
12.
Silong, S. and Rahman, L. (2000). Graft Copolymerization of Methyl Acrylate onto Sago Starch Using Ceric Ammonium Nitrate as an Initiator , J. Appl. Polym. Sci., 76: 516-523 .
13.
Tranquilan-Aranilla, C. , Yoshii, F. , Dela Rosa, A.M. and Makuuchi, K. (1999). Kappa-Carrageenan-Polyethylene Oxide Hydrogel Blends Prepared by Gamma Irradiation , Rad. Phys. Chem., 55: 127-131 .
14.
Pourjavadi, A. and Zohuriaan-Mehr, M.J. (2002). Modification of Carbohydrate Polymers Via Grafting in Air. 1. Ceric-Induced Synthesis of Starch-g-Polyacrylonitrile in Presence and Absence of Oxygen , Starch/Starke, 54: 140-147 .
15.
Pourjavadi, A. and Zohuriaan-Mehr, M.J. (2002). Modification of Carbohydrate Polymers Via Grafting in Air. 2. Ceric-Initiated Graft Copolymerization of Acrylonitrile onto Natural and Modified Polysaccharides , Starch/Starke, 54: 482-488 .
16.
Lee, W.F. and Lin, G.H. (2001). Superabsorbent Polymeric Materials VIII: Swelling Behavior of Crosslinked Poly[Sodium Acrylate-co-Trimethyl Methacryloyloxyethyl Ammonium Iodide] in Aqueous Salt Solutions , J. Appl. Polym. Sci., 79: 1665-1674 .
17.
Athawale, V.D. and Lele, V. (1998). Graft Copolymerization onto Starch. II. Grafting of Acrylic Acid and Preparation of Its Hydrogels , Carbohydr. Polym., 35: 21-27 .
18.
Athawale, V.D. and Lele, V. (1998). Graft Copolymerization onto Starch. 3: Grafting of Acrylamide Using Ceric Ion Initiation and Preparation of its Hydrogels , Starch/Starke, 50: 426-431 .
19.
Athawale, V.D. and Lele, V. (2000). Factors Influencing Absorbent Properties of Saponified Starch-g-(Acrylic Acid-co-Acrylamide) , J. Appl. Polym. Sci., 77: 2480-2485 .
20.
Flory, P.J. (1953). Principles of Polymer Chemistry, Cornell University Press, Ithaca, New York .
21.
Peppas, L.B. and Harland, R.S. (1990). Absorbent Polymer Technology, p. 103, Elsevier, Amsterdam .
22.
Peppas, N.A. and Mikes, A.G. (1986). Hydrogels in Medicine and Pharmacy, vol. 1, p. 27, CRC Press Inc., Boca Raton, Florida .
23.
Chen, J. and Zhao, Y. (2000). Relationship Between Water Absorbency and Reaction Conditions in Aqueous Solution Polymerization of Polyacrylate Superabsorbents , J. Appl. Polym. Sci., 75: 808-814 .
24.
Odian, G. (1981). Principles of Polymerization, Chap. 3, 2nd edn, Wiley, New York .
25.
Hsu, S.C. , Don, T.M. and Chiu, W.Y. (2002). Free Radical Degradation of Chitosan with Potassium Persulfate , Polym. Degrad. Stab., 75: 73-83 .
26.
Branrup, J. and Immergut, E.H. (1989). Polymer Handbook, 3rd edn, Wiley, New York .
27.
Hebeish, A. and Cuthrie, J.T. (1981). Chemistry and Technology of Cellulosic Copolymers, p. 146, Springer-Verlag, Berlin, Heidelberg, New York .
28.
Pass, G. , Phillips, O.G. and Wedlock, D.J. (1977). Interaction of Univalent and Divalent Cations with Carrageenans in Aqueous Solution , Macromolecules, 10: 197-201 .
29.
Hossain, K.S.Miyanaga, K. , Maeda, H. and Nemoto, N. (2001). Sol-Gel Transition Behavior of Pure -Carrageenan in both Salt-Free and Added Salt States , Biomacromolecules, 2: 442-449 .
30.
Bongaerts, K. , Reynaers, H. , Zanetti, F. and Paoletti, S. (1999). Equilibrium and Nonequilibrium Association Processes of κ-carrageenan in Aqueous Salt Solutions . Macromolecules, 32: 683-689 .
31.
Pourjavadi, A. and Zohuriaan-Mehr, M.J. (2003). Superabsorbent Hydrogels from Starch-g-PAN: Effect of Some Reaction Variables on Swelling Behavior , J. Polym. Mater., 20: 113-120 .
32.
Lim, D.W. , Whang, H.S. and Yoon, K.J. (2001). Synthesis and Absorbency of a Superabsorbent from Sodium Starch Sulfate-g-Polyacrylonitrile , J. Appl. Polym. Sci., 79: 1423-1430 .
33.
Barbucci, R. , Maganani, A. and Consumi, M. (2000). Swelling Behavior of Carboxymethylcellulose Hydrogels in Relation to Cross-Linking, pH, and Charge Density , Macromolecules, 33: 7475-7480 .
