“New ester and lactone end-functionalized N-vinyl-2-pyrrolidinone oligomers”

New oligomers of N-vinyl-2-pyrrolidinone functionalized at one end with either ester or lactone functions were obtained by radical polymerization in the presence of different ester (methyl isobutyrate and methyl phenylacetate) and lactone (ε-caprolactone, δ-valerolactone and γ-butyrolactone) compounds as chain transfer agents. The oligomeric samples obtained were characterized in terms of molecular weight and molecular weight distribution by means of analytical size exclusion chromatography (SEC), using purposely synthesized poly(N-vinyl-2-pyrrolidinone) standards. The chain transfer constant CT of either methyl isobutyrate, δ-valerolactone, or γ-buryrolactone towards N-vinyl-2-pyrrolidinone were determined with the help of the known cumulative number-average degree of polymerization X̄n and monomer conversion Yt of the samples during the reaction.