Cinchonidinyl-Based Acrylic and Methacrylic Homopolymers: Synthesis, Characterization, and Antibacterial Activity

The monomers (5-ethenyl-1-azabicyclo [2.2.2] octan-2-yl)-quinolin-4-ylmethyl acrylate (EAOQMA) and (5-ethenyl-1-azabicyclo [2.2.2] octan-2-yl)-quinolin-4-ylmethyl methacrylate (EAOQMMA) were synthesized by reacting (5-ethenyl-1-azabicyclo octan-2-yl)-quinolin-4-ylmethanol [cinchonidine] with acryloylchloride and methacryloyl chloride, respectively, in the presence of triethylamine. The homopolymers were synthesized by the free radical polymerization in tetrahydrofuran at 70 ± 2°C in nitrogen atmosphere using 2,2′-azobisisobutyronitrile as an initiator. The monomers and homopolymers were characterized by UltraViolet (UV), Fourier transform infrared, Proton-Nuclear Magnetic Resonance (1H NMR), and Carbon-13 Nuclear Magnetic Resonance (13C NMR) spectroscopic techniques. The glass transition temperature (Tg, °C) was determined by differential scanning calorimetry. The thermal stability of the poly(EAOQMMA) was performed by thermogravimetric analysis, which showed higher thermal stability of about 706°C than that of poly(EAOQMA). The antibacterial activity of monomers and polymers has been evaluated by determining the inhibitory zone diameters against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Pseudomonas aeruginosa), in which cinchonidine acrylate and Cinchonidine methacrylate homopolymer showed better activity than their corresponding monomers. Surface morphology of the monomers and polymers were examined by Scanning Electron Microscope (SEM) analysis.