Synthesis of poly(acrylamide-co-methyl methacrylate) chemically cross-linked hydrogels and their application in controlled release of model drugs

Poly(acrylamide-co-methyl methacrylate) (poly(AAm-co-MMA)) hydrogels with chemical cross-links have been prepared using two monomers (acrylamide and methyl methacrylate) and cross-linker (N,N'-methylene his acrylamide) (NN'-MBA) in different stoichiometric ratios. The effects of monomer ratio and cross-linking agent concentration on the swelling behaviour of poly(AAm-co-MMA)hydrogels were investigated. Swelling parameters such as equilibrium degree of swelling and swelling ratio, and network parameters such as molecular mass between cross-links (M-c) and cross-link density (q) were determined. Depending on the monomer concentration, the M-c values of hydrogels were varied from 1452.00 to 10602.16 g/mol and q values of hydrogels were varied from 6.09 x 10(2) to 0.75 x 10(2). Depending on the cross-linking agent concentration the M-c values of hydrogels were varied from 1463.57 to 2143.94 g/mol and q values of hydrogels were varied from 5.63 x 10(2) to 3.99 x 10(2). The ability of this co-polymeric hydrogel for use in controlled release of model drugs such as benzoic acid (BA), salicylic acid (SA) and p-nitroaniline (P-NA) was also studied.