Synthesis, Characterization, Thermal Studies, and Antimicrobial Screening of Poly (acrylate)s Bearing 4-Methyl Coumarin Side Groups

This paper demonstrates the synthesis and characterization of a new functional acrylic monomer, 7-acryloyloxy 4-methyl coumarin (AOMC) and its copolymers with methyl acrylate (MA). The polymerization was conducted by free radical polymerization technique using AIBN as an initiator at 70±1°C. The resulting polymers were characterized by FTIR and 1H NMR techniques, solubility study and their inherent viscosity measurements. Gel permeation chromatography (GPC) was used to find out the molecular weights of homopolymers and copolymers. The number average molecular weight of copolymers was found to increase with increase in mole fraction of AOMC. The polymers showed moderate thermal stability which were determined by thermogravimetry (TG) and differential thermal anlaysis (DTA). Copolymers compositions were determined by 1H NMR spectra. Further, the linearization method of Finemann-Ross (rAOMC =0.7315; rMA =0.8439), Kelen-Tudos (rAOMC =0.7734; rMA = 0.8650), and extended Kelen-Tudos (rAOMC = 0.7663; rMA = 0.8554) were employed to calculate the monomer reactivity ratios. These values suggest that MA is more reactive than AOMC. Antimicrobial activities of different copolymers synthesized were also studied against different bacteria, fungi, and yeasts and it was observed that their antimicrobial activities differ from each other depending on the AOMC content in copolymers.