To improve mechanical properties of polymer films; sodium alginate (SA) films was prepared with ethylene glycol (EG) and photocured. The formulation was prepared at various concentration with EG and photoinitiator (2%) in methanol. The mechanical properties were optimized in case of monomer (EG) concentration, soaking time, and radiation dose of intensities. The highest polymer loading (PL) was 7.1% and tensile strength (TS) of the film was 37.9 MPa were found for 3 min soaking in 5% EG containing formulation at 20th pass of UV radiation; the highest value (22%) of elongation at break (Eb) was obtained at 1 min soaking time at 15th passes of UV doses. The mechanical properties improvement of the films varied acrylic monomers; such as 2-ethylhexylacrylate (EHA), 1,4-butanediol diacrylate (BDDA), and trimethylpropane triacrylate (TMPTA) were used as additives (2%) in the optimized formulation. The highest PL (12.7%) and TS (42.2 MPa) of the films are at 5% EG, 2% TMPTA, and 2% photoinitiator in methanol at 3 min soaking time at 20th pass of UV radiation. The highest Eb (25%) was obtained using additives 2% EHA additives in 5% EG and 2% photoinitiator in methanol at 3 min soaking time. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012