화학공학소재연구정보센터
Polymer Bulletin, Vol.70, No.12, 3475-3485, 2013
Poly(L-lactide) initiated by silver N-heterocyclic carbene complexes: synthesis, characterization and properties
Poly(l-lactide) (PLLA) was successfully synthesized by ring-opening polymerization (ROP) in bulk using silver N-heterocyclic carbene (Ag-NHC) complex. The effect of reaction time, temperature and monomer/initiator ratio on polymerization process were determined. The optimum conditions were found as 130 A degrees C, 4 h and M/I molar ratio of about 100. The polymers were characterized by FTIR, H-1-NMR, GPC and TG. High-molecular-weight PLLA (M (w) = 3.78 x 10(4), M (n) = 1.91 x 10(4), PDI = 1.97) was synthesized by the ROP of l-lactide (LLA) with bis-(N-methyl N'-dodecylimidazole) silver(I) di-bromo argentate (1a) in bulk. The effect of different N-substituted ligand groups on the polymerization was studied. The antimicrobial activity of the synthesized polymers were investigated by using minimum inhibitory concentration test against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli and Pseudomonas aeruginosa). It was observed that the synthesized polymers displayed moderate antimicrobial activity.