On the Mechanism of the Ring‐Expansion Polymerization of Thiiranes
On the Mechanism of the Ring‐Expansion Polymerization of Thiiranes
复制标题
硫杂环丙烷扩环聚合机理的研究
DOI：
10.1002/macp.201100030
复制
发表时间：
2011
影响因子：
2.5
通讯作者：
Philipp Vana
中科院分区：
文献类型：
--
作者：
Jan;Philipp Vana
以环双官能团硫酯为引发剂，合成了环状聚合物。PMT产生令人满意的结果，而用MT聚合似乎会产生死聚合物材料作为副产物，TBMT的转化率可以忽略不计。该工艺产量高，转化率高。随着反应时间的延长，分子质量分布呈现出增宽和多模态特征，这是由热力学控制的大环之间的合环反应引起的。PMT的聚合速率符合准一级动力学，活化能为38.8 kJ mol−1.1H，核磁共振、ESI - MS和与分子量无关的玻璃化转变温度证明了环状聚合物的存在。
Ring polymers are synthesized using a cyclic bifunctional thioester as initiator for REP of thiiranes. PMT yields satisfactory results, whereas polymerization with MT appears to develop dead polymeric material as by‐product and TBMT gives only negligible conversion rates. The process produces high yields and high conversion rates. The corresponding molecular weight distributions show increasing broadening and multimodal character with increasing reaction time due to thermodynamically controlled ring‐merging reactions between macrocycles. The polymerization rate of PMT obeys a pseudo first‐order kinetics with an activation energy of 38.8 kJ mol−1.1H NMR, ESI‐MS, and glass transition temperatures independent of the molecular weight demonstrate the presence of cyclic polymer.