Multiple effects achieved with a single agent of O-carboxymethyl chitosan exhibiting cross-linking and antibacterial properties

Different modifiers are often added to coatings to impart a variety of special functions to the coating materials. Due to the interactions between their different properties, this can result in a decline in system stability and complex formulations, with the properties offsetting each other and the emergence of new film disadvantages. Modifiers characterized by multiple advantageous properties can be used to address these problems. In this study, O-carboxymethyl chitosan was used as the cross-linking and antibacterial agent for room-temperature self-crosslinked polyacrylate coatings, resulting in coatings with excellent mechanical properties and antibacterial characteristics, which were then successfully applied to wood coatings. The results revealed that with an increase in O-carboxymethyl chitosan content from 0 wt% to 10 wt%, the cross-linking density of the coating increased from 281.41 to 690.11 mol/m3, the tensile strength increased from 9.82 to 20.17 MPa, the elastic modulus increased from 51.05 to 343.83 MPa, the fracture work increased from 28.86 to 33.03 MJ/m3, the pencil hardness of the coating increased from 3 to 4H, and the width of the Staphylococcus aureus bacteriostatic ring increased from 1.02 to 11.12 mm. The waterborne polyacrylate coatings with excellent mechanical properties and antibacterial properties prepared using O-carboxymethyl chitosan as the cross-linking and antibacterial agent could potentially be used in various fields for the fabrication of materials used in the medicinal industry, wood coatings, and leather coatings.