Hydrogel copolymers based on N,N-dimethyl acrylamide (DMA) and acrylic acid (AAc) were synthesized using a solution polymerization technique with different monomer ratios and ammonium persulfate as an initiator. This paper investigates the thermal stability, physical and chemical properties of the hydrogel copolymer. Testing includes Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and elemental analysis (CHNS). The copolymer composition was determined by elemental analysis, and the reactivity ratios of monomers were calculated through linearization methods such as Fineman–Ross (FR), inverted Fineman–Ross (IFR), Kelen–Tudos (KT) and Mayo–Lewis (ML). Good agreement was observed between the results of all four methods. The ratio of r₁ and r₂ were 0.38 (r₁) and 1.45 (r₂) (FR), 0.38 (r₁) and 1.46 (r₂) (IFR), 0.38 (r₁) and 1.43 (r₂) (KT), and 0.38 (r₁) and 1.45 (r₂) (ML). Hydrogel copolymers exhibited good thermal stability, and SEM showed three-dimensional porous structures. Antibiotic-free and antibiotic-loaded hydrogels demonstrated antimicrobial properties against both Gram-positive and Gram-negative bacteria. As the ratio of DMA in hydrogel copolymer increased, the activity of copolymer against bacteria enhanced. The results indicated that these hydrogels have the potential to be used as antibacterial materials.

Oriental Journal of Chemistry is a peer reviewed quarterly research journal of pure and applied chemistry. It publishes standard research papers in almost all thrust areas of current chemistry of academic and commercial importance. It provides a platform for rapid publication of quality research papers, reviews and chemistry letters. Oriental Journal of Chemistry is abstracted and indexed in almost all reputed National and International agencies.

This paper investigates the swelling properties of homopolymer and copolymer hydrogels. Copolymeric hydrogels based on N, N-dimethyl acrylamide and acrylic acid (poly(DMA-co-AAc) as well as homopolymer hydrogels based on acrylic acid (polyAAc) were synthesized by radical technique in aqueous solutions using ammonium persulfate as an initiator and N, N-methylene-bis-acrylamide as a crosslinking agent. The properties of hydrogels examined including scanning electron microscopy (SEM) and FT-IR. The results indicate that the poly(DMA-co-AAc) copolymer has a high swelling ability in an aqueous solution. The swelling of hydrogels were achieved a maximum degree and diameter of 270 and 63mm in water, respectively. The swelling behavior of these hydrogels was investigated to determine function of the effect of pH and polymeric compositions.