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Synthesis and Characterization of Block Copolymers of Polyoxyethylene and Polylactide with Different Architectures
Author(s) -
Mai Shaomin,
Abbot Annie,
Norton David,
McKean Robert,
Ryan Anthony J.
Publication year - 2009
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.200900041
Subject(s) - copolymer , materials science , polymer chemistry , crystallization , polyester , miscibility , crystallinity , glass transition , lactide , ethylene oxide , peg ratio , ethylene glycol , polyethylene glycol , polymer , chemical engineering , amorphous solid , organic chemistry , chemistry , composite material , finance , economics , engineering
Diblock and triblock copolymers were prepared from polyethylene glycol (PEG, $\overline M _{\rm n}$ = 2 000), L ‐lactide and D , L ‐lactide. A novel method was developed to prepare high‐molecular‐weight multiblock copolymers by transesterification of a PEG/succinic acid polyester with poly( L ‐lactide). Molecular weights were monitored by GPC and overall composition was checked by 1 H NMR. Crystallinity, bulk microstructure, and the glass transition were investigated by DSC and simultaneous SAXS/WAXS/DSC, and surface properties by measurement of advancing contact angle. It is found that the crystallization of the poly(ethylene oxide) (PEO) block is very much affected by the position of the PEO block in the copolymer and by the length and the state of the polylactide block. Both DSC and WAXS showed that the crystallization of PEG2000 block was very much suppressed when covalently bonding to polylactide (PLA) blocks. These methods also confirmed good miscibility between amorphous PLA and PEG blocks. The preparation of fiber by electrospinning demonstrates the target application of the multiblock copolymers in tissue engineering.