Synthesis of Eight-shaped Poly(ethylene oxide) by the Combination of Glaser Coupling with Ring-opening Polymerization

2011 ◽  
Vol 32 (20) ◽  
pp. 1658-1663 ◽  
Author(s):  
Guowei Wang ◽  
Xiaoshan Fan ◽  
Bin Hu ◽  
Yannan Zhang ◽  
Junlian Huang
Keyword(s):  
Ethylene Oxide ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Glaser Coupling

Biodegradable copolymers based on poly(ethylene oxide), polylactide and polydepsipeptide sequences with functional groups

e-Polymers ◽  
2001 ◽  
Vol 1 (1) ◽  
Author(s):  
Yakai Feng ◽  
Doris Klee ◽  
Hartwig Höcker
Keyword(s):  
Block Copolymers ◽  
Ethylene Oxide ◽  
Aspartic Acid ◽  
Functional Groups ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Biodegradable Copolymers ◽  
Protective Groups ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

AbstractFor the purpose of increasing the hydrophilicity of polylactide, new block copolymers with protected functional groups, poly(lactide-co-(S)-b-benzyl aspartate)-poly(ethylene oxide)-poly(lactide-co-(S)- b-benzyl aspartate), were synthesized via ring-opening polymerization of D,L-lactide and (3S, 6R,S)-3- [(benzyloxycarbonyl)methyl]-6-methylmorpholine-2,5-dione in the presence of hydroxyltelechelic poly(ethylene oxide) (PEO) as an initiator at 140 °C for 24 h. The benzyl protective groups of the block copolymers were completely removed to give poly(lactide-co-(S)-aspartic acid)-PEO-poly(lactide-co-(S)-aspartic acid), (poly(DLLA-co-Asp)-b-PEO-b-poly(DLLA-co-Asp)). This shows lower crystallization and melting temperature compared with the polymers before deprotection. Poly(DLLA-co-Asp)-b-PEO-b-poly(DLLA-co-Asp) with 55.6 wt.-% of PEO is more hydrophilic, shows higher water absorption and is degraded faster than with 39.5 wt.-% of PEO.

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