Poly(ionic
liquid)s (P(IL)s) of different degrees of polymerization
(10, 50, and 100) were prepared via RAFT polymerization using an alkyne-terminated
xanthate as transfer agent, with a monomer conversion of up to ∼80%
and a Đ
M of 1.5 for P(IL)100. Subsequently, P(IL) chains were coupled to 15N-labeled
azido-functionalized hydroxyethyl cellulose (HEC), forming graft copolymers
of HEC with different chain length and graft densities, which were
characterized using (13C and 15N) CP-MAS NMR
and FT-IR spectroscopies. The antibacterial activities of HEC-g-P(IL)s were tested against Escherichia
coli and Staphylococcus aureus and were comparable to ampicillin, a well-known antibiotic, demonstrating
efficient activity of the graft copolymers against bacteria. Moreover,
HEC-g-P(IL)s were slightly more effective against E. coli than S. aureus. A decrease in graft density of P(IL)10 on the HEC backbone
decreased the activity of the graft copolymers against both bacteria.
These findings suggest that HEC-g-P(IL) could find
applications as an antiseptic compound, for example, in paint formulation.