The transformation of cellulose acetate into a new biocidal polymer by effluent-free grafting in supercritical carbon dioxide

The study reports an effluent-free, green process for the production of materials with favorable antibiofilm properties by cellulose acetate grafting with quaternary ammonium compounds in supercritical carbon dioxide. Two quaternary ammonium compounds, N-(2-Hydroxyethyl)-N,N-dimethylundecan-1-aminium Bromide and N-(11-Hydroxyundecanyl-N,N-dimethyltetradecan- 1-aminium Bromide, were synthesized and chemically attached to cellulose acetate via hexamethylene diisocyanate as a linker under the conditions of 30 MPa and 70 °C. The polymer modification occurred in its whole volume. The chemical conversion led to a decrease in the degree of crystallinity and the appearance of a rugged polymer surface. However, the cross-section imaging of the newly obtained materials revealed a compact polymer structure. The functionalized materials acquired hydrophobic properties. Microbiological tests showed the impossibility of Staphylococcus aureus ATCC 29213, Methicillin-resistant Staphylococcus aureus ATCC 43300, Escherichia coli ATCC 10536, and Salmonella Enteritidis ATCC 13076 attachment to the material obtained by the cellulose acetate grafting procedure with N-(11-Hydroxyundecanyl-N,N-dimethyltetradecan- 1-aminium Bromide.