Synthesis and antibacterial investigation of cationic waterborne polyurethane containing siloxane

Abstract

In this work, a cationic waterborne polyurethane (CWPU) dispersion containing siloxane in the side chain has been developed from 3-(2-aminoethylamino)propyldimethoxymethylsilane (APTS), using 3-dimethylamino-1,2-propanediol (DMAPD) as an ion centre. The DMAPD content was fixed constant and the effect of the APTS molar content on the particle size distribution and antibacterial performance of the CWPU dispersion, and hydrophobicity, water uptakes, crystallinity, thermal stability, surface morphology, of the forming CWPU films were wholly explored. The results indicated that more application of APTS into the CWPU might help strengthen the thermal stability and hydrophobicity for the cured films. What's more, as the molar content of APTS increased from 1% to 9%, all the CWPU dispersions reveal enhanced antibacterial activity against Escherichia coli and Staphylococcus aureus, and their maximum inhibition zone could reach 13.71 mm. This distinctly shows their great potential as antimicrobial coating materials. This work is the first in-depth study on the relationship between alkyl siloxane content and the antibacterial properties of cationic waterborne polyurethane dispersions and the resulting films.