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Synthesis and Characterisation of Poly[oligo( ε ‐caprolactone) L ‐malate‐ graft ‐poly( L ‐lactide)]
Author(s) -
Hahn Christian,
Keul Helmut,
Möller Martin
Publication year - 2010
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.200900564
Subject(s) - polymer chemistry , caprolactone , condensation polymer , lactide , transesterification , chemistry , copolymer , diol , ring opening polymerization , malic acid , differential scanning calorimetry , catalysis , polymer , materials science , organic chemistry , physics , citric acid , thermodynamics
Graft copolyesters with a PCL backbone and PLLA side chains were successfully prepared in three steps avoiding transesterification. First ε ‐caprolactone was polymerised with 1,6‐hexane diol as initiator to obtain hydroxytelechelic oligo( ε ‐caprolactone)s. These diols were then subjected—in the second step—to polycondensation with L ‐malic acid yielding in linear poly[oligo( ε ‐caprolactone) L ‐malate] having secondary hydroxyl functions in the side chain. For both reactions scandium triflate Sc(OTf) 3 was used as a catalyst. In the third step various amounts of L ‐lactide were grafted from the polymer backbone using Zn(oct) 2 as catalyst. The successful reaction was confirmed by NMR and SEC (size exclusion chromatography) analysis. Further the thermal properties of the graft copolymers with different graft lengths were determined via differential scanning calorimetry.