COMPARISON OF CALIBRATION WITH POLY(PROPYLENE GLYCOL) AND POLY(STYRENE) STANDARDS IN SIZE-EXCLUSION CHROMATOGRAPHY MEASUREMENTS FOR CHARACTERIZATION OF OLIGO(LACTONE) MACROMONOMERS

The calibration of size exclusion chromatography (SEC) measurements fo r determination of the molecular weights of oligo(lactone) macromonome rs was carried out by use of poly(propylene glycol) (PPG) and poly(sty rene) (PS) standards. The results are compared with those obtained by end-group analysis with H-1-NMR as well as those calculated from the m olar ratio of lactone and initiator in the initial mixture regarding t he conversion of lactone. Clearly, calibration with PPG standards resu lts in a better correspondence of molecular weights from SEC measureme nts with those of end-group analysis and calculated ones compared to c alibration with PS standards.