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Polymerization of L ‐lactide and ϵ‐caprolactone in the presence of methyl trifluoromethanesulfonate
Author(s) -
Rangel Irma,
Ricard Michèle,
Ricard Alain
Publication year - 1994
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1994.021950908
Subject(s) - caprolactone , polymer chemistry , lactide , cationic polymerization , polymerization , ring opening polymerization , chemistry , monomer , trifluoromethanesulfonate , copolymer , enthalpy , catalysis , polymer , organic chemistry , thermodynamics , physics
The cationic polymerization of L ‐lactide and ϵ‐caprolactone initiated by methyl trifluoromethanesulfonate in nitrobenzene was studied. The monomer conversion and the average molecular weight decrease when the temperature increases. The kinetics constants for L ‐lactide and ϵ‐caprolactone polymerizations are, respectively, equal to 1,7·10 −3 min −1 and 1,60·10 −3 min −1 at 50°C. The thermodynamic parameters were determined from the temperature dependence of the equilibrium monomer concentration. Thus for L ‐lactide and ϵ‐caprolactone polymerization the enthalpy and entropy values are, respectively, equal to Δ H ( L ‐lactide) = −24,9 kJ/mol; Δ S ( L ‐lactide) = −25 J/(mol·K) and Δ H (ϵ‐caprolactone) = −15,35 kJ/mol; Δ S (ϵ‐caprolactone) = −35 J/(mol·K).