Thermal polycondensation of poly(diol citrate)s with tethered quaternary ammonium biocides

The synthesis and characterization of a series of novel, antimicrobial, aliphatic polyesters based on citric acid, alkanediols, and quaternary ammonium salt (QAS) diols is described. These materials possess a wide range of mechanical and thermal properties (storage modulus, E' = 1.03-17.53 MPa at 25 degrees C; T-g = 215.7-38.6 degrees C) primarily dictated by alkanediol selection and the presence of biocide. Surface analysis via contact angle and FTIR-ATR studies indicate the presence of biocide at the material/air interface providing high antimicrobial activity (5-7 log kill of S. aureus over controls) for all materials containing tethered QAS. Hydrolysis of these cross-linked materials was also highly controlled based on the QAS, alkanediol structure, and curing duration; and significant hydrolysis occurs in as little as 4 weeks.