Synthesis and characterization of antimicrobial materials derived from natural polymers in-situ copolymerization

Natural polymer antimicrobial materials not only have the advantages of reducing the residual toxicity, increasing efficiency, selectivity, and prolonging the lifetime as an antimicrobial material but also have the extensive applications in human daily life. Here, grafting guanidine derivatives onto natural polymers (starch and cotton) were synthesized via in situ free-radical polymerization with ceric ammonium nitrate as an initiator in the glacial acetic acid solution. The as-prepared materials were characterized by infrared spectroscopy and elemental analysis. The antimicrobial activity of the materials was studied via investigating the diameter of the inhibition zone, the minimum inhibitory concentration, in addition to the influence of time, temperature, and concentration on the growth of four colonies. The as-prepared antimicrobial materials both had the properties of anti-gram-negative bacteria (Escherichia coli ATCC 25922), gram-positive bacteria (Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 25923) and had the exceptional ability of against fungus (Candida albicans ATCC 10231), whereas no toxicity to the mammalian erythrocyte.