Ring-opening copolymerization of (R,S)-β-butyrolactone and ε-caprolactone using sodium hydride as initiator
Copolymers of racemic β-butyrolactone ((R,S)-BL) and ε-caprolactone (CL), were synthesized by ring-opening polymerization initiated by sodium hydride (NaH). The initiator exhibited a satisfactory catalytic activity, producing copolymers whose yields are greatly influenced by the fe...
Saved in:
| Format: | Article |
|---|---|
| Language: | English |
| Published: |
Budapest University of Technology and Economics
2010-07-01
|
| Series: | eXPRESS Polymer Letters |
| Subjects: | |
| Online Access: | http://www.expresspolymlett.com/letolt.php?file=EPL-0001481&mi=cd |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Copolymers of racemic β-butyrolactone ((R,S)-BL) and ε-caprolactone (CL), were synthesized by ring-opening polymerization initiated by sodium hydride (NaH). The initiator exhibited a satisfactory catalytic activity, producing copolymers whose yields are greatly influenced by the feed monomer ratio, CL/BL. All polymers obtained were characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and wide angle X-rays scattering, WAXS. The molar composition of copolyesters determined by 1H-NMR spectra, showed that the incorporation of CL is favoured over the incorporation of (R,S)-BL. Gel permeation chromatography and 13C-NMR spectra indicated that CL/BL copolymers had block sequence distribution. The TGA analysis of copolymers showed that these copolymers are stable up to temperatures near 200°C, followed by a decomposition process in two steps; the first one is attributed to the (R,S)-BL block degradation and the second to the remaining PCL block. The crystallization process of these copolymers was studied by DSC and WAXS showing that the amorphous (R,S)-BL segments chains did not affect the crystallinity of the PCL blocks. |
|---|---|
| ISSN: | 1788-618X |