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Organobase‐Catalyzed Synthesis of Multiarm Star Polylactide With Hyperbranched Poly(ethylene glycol) as the Core
Author(s) -
Schömer Martina,
Frey Holger
Publication year - 2011
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.201100386
Subject(s) - polymer chemistry , copolymer , ring opening polymerization , ethylene glycol , monomer , glass transition , polymerization , materials science , lactide , polyol , melting point , peg ratio , condensation polymer , crystallization , chemical engineering , chemistry , polymer , polyurethane , organic chemistry , composite material , finance , economics , engineering
Multiarm star copolymers consisting of the polyether‐polyol hyperbranched poly(ethylene glycol) ( hb PEG) as core and poly( L ‐lactide) (PLLA) arms are synthesized via the organobase‐ catalyzed ring‐opening polymerization of lactide using hb PEG as a multifunctional macroinitiator. Star copolymers with high molecular weights up to 792 000 g mol −1 are prepared. Detailed 2D NMR analysis provides evidence for the attachment of the PLLA arms to the core and reveals that the adjustment of the monomer/initiator ratio enables control of the arm length. Size exclusion chromatography measurements show narrow molecular weight distributions. Thermal analysis reveals a lower glass transition temperature, melting point, and degree of crystallization for the star‐shaped polylactides compared to linear polylactide.