• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>European journal of mass spectrometry >A comparison of electrospray-ionization and matrix-assisted laser desorption/ionization mass spectrometry with nuclear magnetic resonance spectroscopy for the characterization of synthetic copolymers
【24h】

A comparison of electrospray-ionization and matrix-assisted laser desorption/ionization mass spectrometry with nuclear magnetic resonance spectroscopy for the characterization of synthetic copolymers

机译：电喷雾电离和基质辅助激光解吸/电离质谱与核磁共振光谱的比较，用于表征合成共聚物

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

Electrospray ionization (ESI-MS) and matrix assisted laser desorption-ionization (MALDI-MS) were used to determine the composition (monomer ratios) and structure (end group analysis) relative to 1H NMR spectroscopy and theoretical predictions for three different copolymers: poly(butyl acrylate/vinyl acetate) (PBA/PVAc), poly(methyl methacrylate/vinyl acetate) (PMMA/PVAc) and poly(butyl acrylate/methyl methacrylate) (PBA/PMMA). We found that the ESI results were in excellent agreement with 1H NMR spectroscopy for PBA/PVAc and PBA/PMMA copolymers whereas there was more divergence in the case of PMMA/PVAc. In the case of PBA/PMMA copolymers similar distributions of products were observe by ESI-MS and MALDI-MS with the two major products classes differing by their end-groups. One class has hydrogen and dodecylthio end groups while in the other the dodecylthio has been replaced by α-cyanoisopropyl from the initiator. The relative abundance of these distributions as a function of copolymer conversion for a series of reaction conditions was investigated by both ESI and MALDI. MALDI results consistently underestimated (relative to ESI) the butylacrylate monomer ratio in PBA/PMMA and the abundance of co-polymer oligomers terminated by a dodecylthio group from the chain transfer agent.
机译：使用电喷雾电离（ESI-MS）和基质辅助激光解吸电离（MALDI-MS）来确定相对于1H NMR光谱的组成（单体比）和结构（端基分析）以及三种不同共聚物的理论预测：聚（丙烯酸丁酯/乙酸乙烯酯）（PBA / PVAc），聚（甲基丙烯酸甲酯/乙酸乙烯酯）（PMMA / PVAc）和聚（丙烯酸丁酯/甲基丙烯酸甲酯）（PBA / PMMA）。我们发现ESI结果与PBA / PVAc和PBA / PMMA共聚物的1H NMR光谱非常吻合，而PMMA / PVAc的差异更大。在PBA / PMMA共聚物的情况下，通过ESI-MS和MALDI-MS观察到相似的产物分布，两种主要产物类别的端基不同。一类具有氢和十二烷基硫基端基，而另一类具有由引发剂中的α-氰基异丙基取代的十二烷基硫基。通过ESI和MALDI研究了一系列反应条件下这些分布的相对丰度与共聚物转化率的关系。 MALDI结果始终低估（相对于ESI）PBA / PMMA中的丙烯酸丁酯单体比率，以及来自链转移剂的十二烷基硫基封端的共聚物低聚物的丰度。

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