第一作者: |
Zhou, L (Zhou, Li); Wang, ZY (Wang, Zhenyu); Xu, GQ (Xu, Guangqiang); Lv, CD (Lv, Chengdong); Wang, QG (Wang, Qinggang); |
联系作者: |
Zhou, L (Zhou, Li); Wang, ZY (Wang, Zhenyu); Xu, GQ (Xu, Guangqiang); Lv, CD (Lv, Chengdong); Wang, QG (Wang, Qinggang); |
发表年度: |
2021 |
期: |
12 |
卷: |
12 |
页: |
1806-1815 |
摘要: |
A highly efficient and controllable ring-opening polymerization of lactones (delta-valerolactone, epsilon-caprolactone and rac-lactide) has been achieved by using N-heterocyclic olefin (NHO) and thiourea/urea (TU/U) catalytic systems. This catalytic system showed high ring-opening activity and stereoselectivity, delivering biodegradable polyesters with high chain-end fidelity, controlled molecular weights and narrow molar mass dispersities. A detailed investigation of the structure-activity relationship was performed by exploring five NHOs and fourteen TUs/Us. For a fixed NHO, when the acidity of TUs/Us decreases, the polymerization mechanism changes from the (thio)urea anion to the neutral cooperative activation mode, and the catalytic activity first increases and then decreases, displaying a highly effective interval. For a given TU or U, as the basicity of NHOs increases, the catalytic performance improves correspondingly. Besides, highly isoselective ROP of rac-LA (P-m = 0.93) at -78 degrees C has been also achieved, highlighting the versatility of the NHO/TU(U) system. These findings enrich the type of TU/U and base organocatalyst. |
刊物名称: |
POLYMER CHEMISTRY |
影响因子: |
4.76 |
全文链接: |
https://pubs.rsc.org/en/content/articlelanding/2021/PY/D0PY01747G |