Abstract
A series of linear copolymers of glycolide and 1,3-trimethylene carbonate were synthesized by bulk ring-opening polymerization. The copolymers were characterized by 1H NMR, 13C NMR, viscometry, and differential scanning calorimetry (DSC). The dependency of reaction temperature, reaction time, and the feed composition on the microstructure of the copolymers was examined by 13C NMR analysis. The microstructural analysis using 13C NMR was useful to calculate the average block length of the glycolyl (LG) and trimethylene carbonyl (L T) sequence. The structural change such as transesterification, which was assigned by TGT sequence, was reflected in the average block length and the sequence of each monomeric unit in the copolymer. The average length of glycolyl sequence (LG) was much longer than that of trimethylene carbonyl sequence (LT) in polymerization temperature of 100-150 °C. Upon further increasing the polymerization temperature, the L G decreased, but the change of LT was insignificant. During the polymerization, transesterification did not occur at 100 °C, but it was observed at a polymerization temperature range of 130-200 °C resulting in the decrease in LG. As the composition of trimethylene carbonate increased, LG decreased, but LT do not show remarkable change. DSC results showed a close relationship between crystallinity and nature of microstructural sequence. The crystallinity of block copolymers was mainly decided by the average length of the glycolyl block.
| Original language | English |
|---|---|
| Pages (from-to) | 7953-7960 |
| Number of pages | 8 |
| Journal | Polymer |
| Volume | 46 |
| Issue number | 19 SPEC. ISS. |
| DOIs | |
| Publication status | Published - 8 Sept 2005 |
Bibliographical note
Funding Information:This work was supported by Inha University (2004). C.K. thanks HOMRC for support.
Keywords
- Microstructure
- Poly(glycolide-co-1,3-trimethylene carbonate)
- Transesterification