BEPLS Vol 3 [1] December 2013 140 | P age ©2013 AELS, INDIA Bulletin of Environment, Pharmacology and Life Sciences Bull. Env. Pharmacol. Life Sci., Vol 3 (1) December 2013: 140-142 ©2013 Academy for Environment and Life Sciences, India Online ISSN 2277-1808 Journal’s URL:http://www.bepls.com CODEN: BEPLAD Global Impact Factor 0.533 Universal Impact Factor 0.9804 ORIGINAL ARTICLE Optimization of Effective Parameters onto Hydrolyzed Alginate-g- polyAN Hydrogel Mohammad Sadeghi*, Esmat Mohammadinasab, Fatemeh Shafiei, Hadis Shasavari, Mohammad Javad Khodabakhshi Department of Chemistry, Science Faculty, Islamic Azad University, Arak Branch, Arak, Iran *Corresponding author E-mail: m-sadeghi@iau-arak.ac.ir Department of Chemistry, Science Faculty, Islamic Azad University, Arak Branch, Arak, Iran *Corresponding author E-mail: m-sadeghi@iau-arak.ac.ir ABSTRACT The following synthesis of superabsorbent hydrogel,H-Alg-poly(NaAA-co-AAm), by using ammonium persulfate (APS) as an initiator and sodium hydroxide (NaOH) as a crosslinking agent, we investigated the synthetic parameters affecting on swelling capacity of the hydrogel (i.e., the hydrolysis time and temperature, and concentration of NaOH) to achieve maximum swelling. Keywords: Hydrogel, alginate, acrylonitrile, graft copolymerization, optimization. Received 12/10/2013 Accepted 21/11/2013 ©2013 AELS, INDIA INTRODUCTION In recent years, increasing interest in natural-based superabsorbent hydrogel has developed mainly due to high hydrophobicity, biocompatibility, non-toxicity, and biodegradability of biopolymers. These materials are defined as crosslinked macromolecular networks that can absorb water or physical fluids up to many times of their own weight in a short time, but are not dissolved when brought into contact with water [1]. The absorbed fluids are hardly removable even under some pressure. Because of excellent characteristics, superabsorbent hydrogels are widely used in many fields, such as agricultural and horticultural, disposable diapers, feminine napkins, pharmaceuticals and medical applications [2-4]. This accounts for increase in the worldwide production of superabsorbent polymers (SAPs) from 6000 tons in 1983 to 450000 tons in 1996. Nowadays, the worldwide production of SAPs is more than one million tons in year. Hence, synthesis and investigation of specific and new superabsorbent hydrogels with high absorbency, mechanical strength and initial absorption rate, has been the goal of several research groups in the past decades [5-8]. In this work, effect of the parameters and the subsequent hydrolysis reaction variables on the swelling properties as well as temperature and hydrolysis time was investigated in detail. MATERIALS AND METHODS Materials Sodium alginate (chemical grade, MW 50000) was purchased from Merck Chemical Co. (Germany). The monomer, acrylonitrile (AN, Merck), was used after vacuum distillation. Sodium hydroxide and ethanol as reagent grade were used without further purification. Ammonium persulfate (APS) was used without purification. All other chemicals were of analytical grade. Double distilled water was used for the hydrogel preparation and swelling measurements. Graft copolymerization Graft copolymerization of acrylonitrile onto alginate was carried out with APS radical initiator under argon atmosphere [9, 11]. In a 100 mL flask, alginate (0.50 g) was dissolved in 50 mL of degassed distilled water. The flask was placed in a water bath with desired temperature (35-100 o C). A given amount of monomer, AN (1.62-4.05 g), was added to the flask and the mixture was stirred for 10 min. Then the