Abstract
Poly(ethylene oxide/polylactide/poly(ethylene oxide)) (PEO/PL/PEO) triblock copolymers, in which each block is connected by an ester bond, were synthesized by a coupling reaction between PL and PEO. Hydroxyl-terminated PLs with various molecular weights were synthesized and used as hard segments. Hydroxyl-terminated PEOs were converted to the corresponding acid halides via their acid group and used as a soft segment. Triblock copolymers were identified by Fourier transform infrared spectroscopy, 1H NMR, and gel permeation chromatography. Differential scanning calorimetry (DSC) and X-ray diffractometry of PEO/PL/PEO triblock copolymers suggested that PL and PEO blocks were phase-separated and that the crystallization behavior of the PL block was markedly affected by the presence of the PEO block. PEO/PL/PEO triblock copolymers with PEO 0.75k had two exothermic peaks (by DSC), and both peaks were related to the crystallization of PL. According to thermogravimetric analysis, PEO/PL/PEO triblock copolymer showed a higher thermal stability than PL or PEO.
Original language | English |
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Pages (from-to) | 2545-2555 |
Number of pages | 11 |
Journal | Journal of Polymer Science, Part A: Polymer Chemistry |
Volume | 40 |
Issue number | 15 |
DOIs | |
State | Published - 1 Aug 2002 |
Keywords
- Biodegradable
- Biodegradable polymer
- Biomaterials
- Block copolymers
- Poly(ethylene oxide)
- Polylactide
- Triblock copolymer