Preparation of Highly Effective Antibacterial Cotton Fabrics Based on Bifunctional Reactive N-Halamine

Two novel halogenated triazine amine N-halamine antimicrobial precursors, sulfuric acid mono-(2-{4-[4-chloro-6-(2,2,6,6-tetramethyl-piperidin-4-yloxy)-[1,3,5]triazin-2-ylamino]-benzenesulfonyl}-ethyl) ester sodium (PT) and sulfuric acid mono-(2-{4-[4-(3-pyridinecarboxylic sodium)-6-(2,2,6,6-tetramethyl-piperidin-4-yloxy)-[1,3,5]triazin-2-ylamino]-benzenesulfonyl}-ethyl) ester sodium (CPT), were designed, synthesized, and applied onto cotton fabrics to obtain antibacterial properties. The molecular structures of PT and CPT contained two reactive groups of vinyl sulfone and nicotinic acid, which increased the reaction with cotton fabrics compared with other antibacterial agents. The dyeing process of reactive dye was selected as the finishing method due to the similar structures of antibacterial agents to bifunctional group reactive dyes. The treated cotton fabrics were chlorinated with sodium hypochlorite to obtain antibacterial functionality. The chlorinated fabrics achieved outstanding antibacterial properties against Escherichia coli O157:H7 and Staphylococcus aureus with short contact time. Moreover, the stability measurement exhibited that the chlorine on the samples could be repaired by the diluted sodium hypochlorite solution after washing and long-time storage. In addition, the mild low-temperature process reduced fabric damage, and only about 10% and 15% of the original tensile strength was missing after finishing and chlorination in both the warp and weft directions. Compared to the traditional pad–dry–cure technique, the process developed of antimicrobial cotton had some advantages such as low salt, energy savings, and maintaining tensile strength.