Preparation of quaternized chitosan/tannic acid coatings on PET textiles and their antibacterial properties

Textiles are prone to bacterial proliferation, which may lead to unpleasant odors, infection, and inflammation. To prepare antibacterial textiles, post-finishing is a convenient and scalable method. However, conventional post-finishing coatings often exhibit poor adhesion to polyethylene terephthalate (PET) textiles, limiting their loading efficiency. This study developed a quaternized chitosan/tannic acid (QACS/TA) bicomponent finishing agent to address this challenge. When the finishing agent contained 2 wt% QACS and 1 wt% TA, the post-finishing coating demonstrated optimized adhesion to PET, resulting in a weight gain of more than 15% for the treated PET textiles. The pyrogallol groups on TA could form abundant hydrogen bonds with ester groups of PET and the amino and hydroxyl groups of QACS, acting as binders between QACS and PET. The treated textiles showed an antibacterial rate of 99.2% against E.coli and almost 100% against S.aureus . This study presents a convenient and effective approach to preparing antibacterial PET textiles with improved coating adhesion.