Kinetic and mechanistic investigation of the ring-opening polymerization of l-lactide initiated by nBu₃SnOnBu using ¹H-NMR

详细信息    查看全文

• 作者：Wanich Limwanich ; Puttinan Meepowpan…
• 关键词：Tri ; n ; butyltin n ; butoxide ; l ; Lactide ; Ring ; opening polymerization ; Kinetics ; 1H ; NMR
• 刊名：Reaction Kinetics, Mechanisms and Catalysis
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：119
• 期：2
• 页码：381-392
• 全文大小：468 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Catalysis
  Industrial Chemistry and Chemical Engineering
  Physical Chemistry
  
• 出版者：Akad茅miai Kiad贸, co-published with Springer Science+Business Media B.V., Formerly Kluwer Academic
• ISSN：1878-5204
• 卷排序：119

文摘

The kinetics of the ring-opening polymerization (ROP) of l-lactide (LL) initiated by tri-n-butyltin n-butoxide (nBu₃SnOnBu) was investigated by proton nuclear magnetic resonance spectroscopy (1H-NMR). The kinetic parameters such as the rate constant (k) and the activation energy (E_a) were determined. The values of k increased with increasing temperature and initiator concentration. The E_a values determined from the ROP of LL initiated by 1.0, 1.5 and 2.0 mol% of nBu₃SnOnBu were 95.9, 87.8 and 72.4 kJ/mol. The molecular weight of poly(l-lactide) (PLL) was successfully controlled by adjusting nBu₃SnOnBu concentration. Furthermore, the number average molecular weight (\(\bar{M}_{n}\)) of these polymers was in the range of 1.1 × 104–3.2 × 104 with molecular weight distribution of 1.4–1.9 and the molecular weight of PLL was higher than poly(ε-caprolactone) under identical synthesis conditions. Furthermore, the molecular weight of the synthesized polymers was lower than the theoretical values (\(\bar{M}_{n}\)(cal)) indicating the occurrence of transesterification.