Synthesis, Characterization and Antibacterial Activity of Novel β-cyclodextrin Polyurethane Materials

The advanced water treatment taken by organic micro-pollution or microbiological pollution water resource has been a hot issue of public concern. In this article, novel quaternary ammonium salt functionalized beta-cyclodextrin polyurethane (QAS-beta-CDPU) microparticles were successfully constructed for above-mentioned pollutants removal. By adjusting the proportion of the chlorine-containing monomers, we studied the effect of different quaternization degree (0%, 20%, 40%, 60%) on solvent resistance and thermal stability. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are recognized as significant human bacterial pathogens, which were used as model bacteria to investigate the antibacterial activity by contact-killing tests. Methylene blue (MB) served as a toxic organic model to quantify the dye wastewater remediation efficiency. Research shows that the reaction of beta-cyclodextrin and diisocyanate can form a cyclodextrin-based carbamate network structure. Since both the cyclodextrin cavity and the carbamate network may remove the dye, the obtained polymer has a double advantage. Besides, the presence of quaternary ammonium groups enables QAS-beta-CDPU microparticles to possess good bactericidal properties. When the quaternization degree is 60%, sterilization rates of QAS-beta-CDPU microparticles are over 96% for S. aureus and E. coli. On basis of this simple, green and economical synthetic route, QAS-beta-CDPU microparticles have the potential to become an ideal multifunctional material in water purification.