Fabrication of crosslinked piperazine polymer coating: Synthesis, characterization and its activity towards microorganisms

• Synthesis of water-soluble piperazine based antimicrobial crosslinked polymer. • Structural characterization using FTIR, NMR ( 1 H NMR, 13 C NMR & DEPT-135) and thermal studies were carried out using DSC and TGA. • Evaluation of antimicrobial activity against various pathogenic microorganisms using disc-diffusion assay and a plausible mechanism is proposed as well. • Polymer coated on glass substrate via spin coating and showed longer-term stability. Henceforth, finds its application in biomedical field, water purification system, etc. A simple, robust one step reaction for the preparation of hydrophilic crosslinked piperazine polymer is presented. The resulting crosslinked polymer was synthesized via solution polymerization technique and characterized using FTIR and NMR spectral studies ( 1 H NMR, 13 C NMR and DEPT-135). The thermal analysis of polymer was done using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) that exhibited glass transition temperature ( T g ) at110 °C. The molecular weight of the synthesized polymer was also determined using gel-permeation chromatography. The synthesized hydrophilic polymer exhibited excellent antimicrobial activity against Gram-negative bacteria ( Escherichia coli ), Gram-positive bacteria ( Staphylococcus aureus ), Fungi ( Candida albicans ) and Tubercular variant ( Mycobacterium smegmatis ). The polymer was coated on glass slide and morphology of the coated surface was determined using scanning electron microscopy (SEM) and chemical stability of coated material in different pH values were tested.