SYNTHESIS AND MOLECULAR-WEIGHT CHARACTERIZATION OF END-FUNCTIONALIZEDN-VINYL-2-PYRROLIDONE OLIGOMERS

New oligomers of N-vinyl-2-pyrrolidone, functionalized at one end with hydroxy functions, were obtained by radical polymerzation in the pres ence of a hydroxylated compound, namely 2-isopropoxyethanol, acting as chain-transfer agent. The oligomeric samples obtained were characteri zed in terms of molecular weight and molecular weight distribution by means of analytical size exclusion chromatography (SEC). To this purpo se, a calibration curve for a set of SEC columns had been determined, making use of poly(N-vinyl-2-pyrrolidone) standards purposely prepared . The chain transfer constant C-T of 2-isopropoxyethanol towards N-vin yl-2-pyrrolidone was determined from the knowledge of the cumulated nu mber-average degree of polymerization ($) over bar X(n) and monomer co nversion Y-t of the samples during the reaction.