First Systematic MALDI/ESI Mass Spectrometry Comparison to Characterize Polystyrene Synthesized by Different Controlled Radical Polymerizations
First Systematic MALDI/ESI Mass Spectrometry Comparison to Characterize Polystyrene Synthesized by Different Controlled Radical Polymerizations
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DOI：
10.1021/ma8013788
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发表时间：
2009-01-13
期刊：
影响因子：
5.5
通讯作者：
Delolme, Frederic
中科院分区：
文献类型：
--
作者：
Ladaviere, Catherine;Lacroix-Desmazes, Patrick;Delolme, Frederic
质谱技术，特别是基质辅助激光解吸/电离飞行时间（MALDI-TOF）和电喷雾电离飞行时间（ESI-TOF）是相当大的兴趣，用于表征非常有吸引力的聚合物产生的受控自由基聚合（CRP）。这项工作提出了一个系统的和实验比较的两种电离方法来分析由五种不同的CRP制备的聚苯乙烯：氮氧自由基介导的聚合（由N-叔丁基-N-[1-二乙基膦酰基-（2.2-二甲基丙基）]氮氧自由基，称为SG 1），原子转移自由基聚合（Cl-和Br-介导），可逆加成-断裂链转移聚合，和反向碘转移聚合。所有的聚苯乙烯链端基在每个CRP聚合，并通过两种质谱技术检测，进行了描述和讨论。还进行了所有CRP聚合物的元素分析以完成这些结果。结果发现，在聚苯乙烯的情况下，通过ESI-TOF比MALDI-TOF质谱检测到的链端基的数目更高。此外。阳离子化盐和电离源对5种CRP-聚苯乙烯在质谱仪中发生的链端基断裂过程起着相当大的作用。考虑到分子量因素，MALDI-TOF质谱法是色谱技术的更好替代方法，而ESI-TOF质谱法低估了平均分子量。
Mass spectrometry techniques, Specifically matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization time-of-flight (ESI-TOF) are of considerable interest for characterizing very attractive polymers resulting from controlled radical polymerizations (CRP). This work proposes a systematic and experimental comparison of both ionization methods to analyze polystyrene prepared by five different CRP: nitroxide-mediated polymerization (mediated by N-tert-butyl-N-[1-diethylphosphono-(2.2-dimethylpropyl)]nitroxide, known as SG1), atom transfer radical polymerization (Cl- and Br-mediated), reversible addition-fragmentation chain transfer polymerization, and reverse iodine transfer polymerization. All polystyrene chain end-groups obtained in each CRP-polymerization, and detected by both mass spectrometry techniques, are described and discussed. Elemental analyses of all CRP-polymers were also carried out to complete these results. It was found that the number of chain end-groups detected is higher by ESI-TOF than MALDI-TOF mass spectrometry in the polystyrene case. Furthermore. the cationization salt as well as the ionization source play a considerable role on the chain end-group fragmentation process occurring in mass spectrometer for the five CRP-polystyrenes. Concerning molecular weight considerations, the MALDI-TOF mass spectrometry is a better alternative to chromatography techniques than ESI-TOF mass spectrometry which under-estimates the average molecular weights.