The interactions of polymeric methylene diphenyl di‐isocyanate (pMDI) and a model Fe–Cr alloy have been studied by X‐ray photoelectron spectroscopy (XPS) and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). Films of two different thicknesses have been investigated: one with an extremely thin pMDI layer in which the interfacial chemistry can be probed directly and a thicker one in which sputter profiling using cluster ions is necessary to expose the interface chemistry for direct analysis. Multivariate analysis (MVA), using principal component analysis (PCA) and nonnegative matrix factorisation (NMF), has been used to identify specific ions associated with the interfacial region of the ToF‐SIMS sputter depth profile and chemical species from the XPS sputter depth profile. As an unsupervised method, this avoids an unconscious bias on the part of the analyst. Specific ions associated with pMDI interactions with both Fe and Cr allow the proposal of two complementary reaction mechanisms, supported by the XPS data. A range of cluster ions is used in this investigation, but the bulk of the work used argon clusters for the XPS depth profiles and Buckminster Fullerene projectiles for the ToF‐SIMS analyses. To ensure that such data were directly comparable, the ToF‐SIMS sputter profiles were repeated in a different system of the same type using argon cluster ions.

中文翻译：

---

聚合亚甲基二苯基二异氰酸酯与Fe-Cr合金之间的界面化学研究

通过X射线光电子能谱（XPS）和飞行时间二次离子质谱（ToF-SIMS）研究了聚合物亚甲基二苯基二异氰酸酯（pMDI）与Fe-Cr合金的相互作用。已经研究了两种不同厚度的薄膜：一种具有非常薄的pMDI层，可以直接探测界面化学，而另一种则具有较厚的厚度，其中必须使用簇离子进行溅射分析以暴露界面化学，以便直接分析。使用主成分分析（PCA）和非负矩阵分解（NMF）进行的多变量分析（MVA）已用于识别与ToF‐SIMS溅射深度分布的界面区域和XPS溅射深度分布的化学物质相关的特定离子。作为一种无监督的方法，这避免了分析师的无意识偏见。与pMDI与Fe和Cr相互作用相关的特定离子允许提出两种互补的反应机理，并得到XPS数据的支持。在这项研究中使用了一系列的簇离子，但是大部分工作使用了用于XPS深度剖面的氩气簇和用于ToF-SIMS分析的Buckminster Fullerene弹丸。为确保这些数据可直接比较，在使用氩气簇离子的相同类型的不同系统中重复进行了ToF-SIMS溅射轮廓。但是大部分工作使用的是XS深度剖面的氩气团簇和ToF-SIMS分析的Buckminster富勒烯弹丸。为确保这些数据可直接比较，在使用氩气簇离子的相同类型的不同系统中重复进行了ToF-SIMS溅射轮廓。但是大部分工作使用的是XS深度剖面的氩气团簇和ToF-SIMS分析的Buckminster富勒烯弹丸。为确保这些数据可直接比较，在使用氩气簇离子的相同类型的不同系统中重复进行了ToF-SIMS溅射轮廓。