MALDI SpiralTOF high-resolution mass spectrometry and Kendrick mass defect analysis applied to the characterization of poly(ethylene-co-vinyl acetate) copolymers.
MALDI SpiralTOF high-resolution mass spectrometry and Kendrick mass defect analysis applied to the characterization of poly(ethylene-co-vinyl acetate) copolymers.
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DOI：
10.1002/rcm.7525
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发表时间：
2016-04-15
期刊：
影响因子：
--
通讯作者：
Sato H
中科院分区：
文献类型：
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作者：
Fouquet T;Nakamura S;Sato H
聚（乙烯- co -醋酸乙烯）共聚物-通常被称为EVA -是一流的工业聚合物，用于从填充物到作为硅太阳能电池封装剂的光伏应用。各种技术已被用于它们的表征，但使用质谱（MS）分析完整的EVA链迄今尚未报道。三种共聚物分别含有18、25和40 wt%的醋酸乙烯酯（VA），采用尺寸-排斥色谱（SEC）和基质辅助激光解吸/电离（MALDI）螺旋-飞行时间（TOF）高分辨率质谱（HRMS）进行了表征。这些结果对整个样品的代表性已使用13C核磁共振波谱检查。最后，Kendrick质量缺陷分析被提出作为一种替代的、用户友好的数据处理方法。通过SEC分离和HRMS质量分析分离出的最短链已经在端基（发现是氢）和共单体组成方面得到了彻底的描述。VA含量成功地从EVA 40 wt%和25 wt%的谱峰分配中得到，而最新EVA 18 wt%的谱峰分配往往被高估（增加了聚乙烯特征）。采用基于质谱数据的Kendrick质量缺陷分析的更快的数据处理方法，也发现了类似的结果。EVA低分子量完整低聚物首次通过质谱进行了广泛表征，并根据核磁共振数据自信地将其结构特征扩展到完整样品。Kendrick质量分析最终构成了一种无需人工分配即可快速评估其VA含量的有效方法。©2016作者。质谱快速通信由John Wiley & Sons Ltd出版。
Poly(ethylene‐co‐vinyl acetate) copolymers – usually referred to as EVA – are first class industrial polymers used for applications ranging from padding to photovoltaics as encapsulant for the silicon solar cells. Various techniques have been used for their characterization but the analysis of intact EVA chains using mass spectrometry (MS) has not been reported so far. Three copolymers containing 18, 25 and 40 wt% vinyl acetate (VA) have been characterized using an off‐line coupling of size‐exclusion chromatography (SEC) and matrix‐assisted laser desorption/ionization (MALDI) spiral‐time‐of‐flight (TOF) high‐resolution mass spectrometry (HRMS). The representativeness of those results for the entire samples has been checked using 13C NMR spectroscopy. Lastly, Kendrick mass defect analysis has been proposed as an alternative and user‐friendly data treatment method. The shortest chains isolated by SEC fractionation and mass‐analyzed by HRMS have been thoroughly described in terms of end‐groups (found to be hydrogens) and co‐monomeric composition. The VA content was successfully derived from the peak assignments in MS spectra for the EVA 40 wt% and 25 wt% while it tended to be overestimated for the latest EVA 18 wt% (increasing poly(ethylene) character). Similar results have been found using a faster data treatment method relying on the Kendrick mass defect analysis of the MS data. EVA low molecular weight intact oligomers have been extensively characterized by MS for the first time and the structural features confidently extended to the full sample according to NMR data. The Kendrick mass analysis finally constituted an efficient method for a fast evaluation of their VA content with no need for manual assignment. © 2016 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd.