Synthesis and Rheological Properties of Polylactide/Poly(ethylene glycol) Multiblock Copolymers

✍ Scribed by Feng Li; Suming Li; Michel Vert

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 128 KB
• Volume: 5
• Category: Article
• ISSN: 1616-5187
• DOI: 10.1002/mabi.200500143

✦ Synopsis

Abstract

Summary: Ring‐opening polymerization of D,L‐lactide was carried out in the presence of poly(ethylene glycol), using Zn powder as catalyst. The hydroxyl‐capped PLA‐PEG‐PLA triblock copolymers were coupled with adipoyl chloride at different molar ratios under mild conditions. N‐Dimethylaminopyridine (DMAP) was used as catalyst of the coupling reaction. The resulting PLA/PEG multiblock copolymers were characterized by various analytical techniques such as IR, ^1^H NMR, SEC, and DSC. Sol‐gel transition properties of the multiblock copolymers were investigated by mechanical rheology. The data showed that the sol‐gel transition temperature and the transition modulus increased with increasing molecular weight and the solution concentration of the multiblock copolymers.

Variation of storage modulus (G′) and loss modulus (G″) as a function of temperature for a 20% sample of MB3.

magnified imageVariation of storage modulus (G′) and loss modulus (G″) as a function of temperature for a 20% sample of MB3.