• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Progress in Artificial Intelligence >Tandem Unzipping and Scrambling Reactions for the Synthesis of Alternating Copolymers by the Cationic Ring-Opening Copolymerization of a Cyclic Acetal and a Cyclic Ester
【24h】

Tandem Unzipping and Scrambling Reactions for the Synthesis of Alternating Copolymers by the Cationic Ring-Opening Copolymerization of a Cyclic Acetal and a Cyclic Ester

机译：通过环状缩醛和环酯的阳离子开环共聚合成交替共聚物的串联解压缩和扰扰反应

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Cationic copolymerization of different types of monomers, 4-hydroxybutyl vinyl ether (HBVE) and epsilon-caprolactone (CL), was explored using EtSO3H as an acid catalyst, producing copolymers with a remarkably wide variety of compositions and sequences. In the initial stage of the reaction, HBVE was unexpectedly isomerized to 2-methyl-1,3-dioxepane (MDOP), followed by concurrent copolymerization of MDOP and CL via active chain end and activated monomer mechanisms, respectively. The compositions and sequences of the copolymers were tunable, depending on the initial monomer concentrations. Moreover, a unique method was developed for transforming a copolymer with no CL homosequences into an "alternating" copolymer by removing MDOP from the system using a vacuum pump. This was achieved by the tandem reactions of depolymerization (unzipping) and random transacetalization (scrambling) under thermodynamic control. Specifically, the unzipping of HBVE homosequences proceeded at the oxonium chain end until a nondissociable ester bond emerged next to the chain end, while the scrambling of the main chain via transacetalization transferred midchain HBVE homosequences into the polymer chain end.
机译：使用EtSO3H作为酸催化剂探索不同类型单体，4-羟基丁酯乙烯基醚（HBVE）和ε-己内酯（CL）的阳离子共聚，产生具有显着各种组合物和序列的共聚物。在反应的初始阶段，HBVE意外地异构化至2-甲基-1,3-二恶己（MDOP），然后通过活性链端和活性单体机制同时进行MDOP和CL的共聚。根据初始单体浓度，可调谐共聚物的组合物和序列。此外，通过使用真空泵从系统中除去MDOP，开发了一种用于将共聚物转化为“交替”共聚物的共聚物的独特方法。这是通过在热力学对照下的解聚（解压缩）和随机转缩法（加扰）的串联反应来实现的。具体地，HBVE同性恋的解压缩在恶阳链端进，直至链端旁边出现的非质友酯键，而主链通过经转常规化转移到聚合物链末端中的中间链HBVE均衡。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号