N-Halamine modified thermoplastic polyurethane with rechargeable antimicrobial function for food contact surface

Abstract

A polymer blend of two N-halamine precursors was prepared and homogeneously incorporated into TPU structure via a solvent casting method, and an N-halamine modified TPU film with rechargeable antimicrobial activity resulted after treating with chlorine bleach. Antimicrobial efficacies were evaluated against both Staphylococcus aureus (S. aureus) and Escherichia coli O157:H7 (E. coli). Results showed that the N-halamine modified TPU film caused 6 log CFU reduction of bacteria reduction within 2 hours of contact. Moreover, the N-halamine modified TPU displayed desirable rechargeability and stability, which maintained sufficient antimicrobial activity after 20 cycles of “discharge–recharge” process and over 4 weeks of storage. Besides, the tensile strength and surface tension of TPU were not adversely affected by N-halamine modification. The N-halamine modified TPU with rechargeable antimicrobial function exhibited great potential as a cheap, safe and effective food contact surface material for preventing food microbial cross-contamination.