An industrially scalable process for imparting poly (ethylene terephthalate) (PET) with durable and rechargeable antibacterial functions

Abstract

Healthcare-associated infections (HAIs), especially those caused by different antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and multidrug resistant Pseudomonas aeruginosa are of growing concern in healthcare facilities. Since 1995, overall incidence rates of MRSA in Canadian hospitals have increased 19-fold, leading to unnecessary suffering by patients and increasing costs to hospitals. There have been many reports that link pathogen-carrying hospital textiles and cases of infections. The development of effective, durable and rechargeable antibacterial healthcare textiles is expected to impede the transmission of infectious microorganisms, and act as an additional prevention measure to infection control. N-chloramines have been proven to be one of the most suitable antimicrobial agents to be immobilized onto healthcare textiles to impart them with potent and rechargeable antimicrobial functions. However, the majority of the hospital used medical textiles are synthetic fibers which are chemically inert and hard to be chemically modified with N-chloramine functions. This study focuses on developing an industry scalable process to durably immobilize N-chloramine onto poly (ethylene terephthalate) (PET), a common synthetic fiber used in healthcare textiles. Many techniques have been reported till now to activate the chemically inert PET surface with reactive functional groups. Among all the techniques, aminolysis and plasma treatments have attracted great attention due to their easy process to introduce functional group onto PET and can be set up for large production. However, aminolysis suffers from polymer degradation and plasma treatments suffer from less deposition which hinders these two processes to produce commercial antibacterial textiles. In this study, a new combined process was introduced by combining aminolysis and plasma treatments in a specific way that not only minimize the problems associated with these two processes but also can create more N-chloramine precursor functional groups onto the surface of PET. The covalently bonded N-chloramine precursor groups can be easily converted to N-chloramine by dilute sodium hypochlorite solution. The presence of nitrogen on the PET substrates after the modification was confirmed by CHNS/O elemental analyzer and ATR/FTIR analysis showing a successful incorporation of N-chloramine precursor. The morphology of the treated fibers was kept relatively similar with a slight decrease in their diameter. Moreover, the tensile strength of the treated fabric was also acceptably maintained. The N-chloramine modified PET presented highly effective antimicrobial properties, even after 50 home launderings the rechargeable treated fabric demonstrated 100% reduction of both MRSA and P. aeruginosa within a contact time of 5 min.