Polyols are being used in a wide range of industrial applications including surfactants and precursors for grafted polymers. The characterization of polyols is of significance in correlating compositions and structures with their properties. We illustrate two real world examples where traditional analytical methods including GPC and NMR failed to reveal compositional differences, but the combination of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), electrospray ionization mass spectrometry (ESI MS), and MS/MS can produce compositional information required for problem solving. The first example involves failure analysis of four ethylene oxide and propylene oxide (EO/PO) copolymer products. The results from the mass spectrometry analysis unequivocally demonstrate that one of the samples has a small variation in copolymer composition, leading to its abnormal activity. The second example is in the area of deformulation of complex polyol mixtures. Two samples displaying similar properties and activities were found to be two different polyol blends. One of the samples is a more cost-effective product. These examples demonstrate that MALDI, ESI MS, and MS/MS should be seriously considered as an integrated component of an overall polyol characterization program in product failure analysis and deformulation.

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry has the potential to become a valuable tool for the compositional analysis of copolymers. For a copolymer composed of structurally very similar building blocks with minor chain length changes, one would expect the relative peak intensities observed in the MALDI mass spectra to reflect its composition, at least within a narrow mass range. However, we show that variations in experimental conditions in MALDI can have a significant effect on the mass spectral appearance of a copolymer. The effects of concentration, laser power, type of matrices and solvents on mass spectra of an ethylene oxide/propylene oxide copolymer are illustrated. These somewhat surprising results show that great care needs to be exercised when interpreting copolymer spectra for compositional analysis, even for copolymers with structurally similar monomers. This work also points out that further studies are needed to better understand and optimize spectral acquisition conditions for reliable copolymer compositional analysis by MALDI.

Matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry has the potential to become a valuable tool for the compositional analysis of copolymers. For a copolymer composed of structurally very similar building blocks with minor chain length changes, one would expect the relative peak intensities observed in the MALDI mass spectra to reflect its composition, at least within a narrow mass range. However, we show that variations in experimental conditions in MALDI can have a significant effect on the mass spectral appearance of a copolymer. The effects of concentration, laser power, type of matrices and solvents on mass spectra of an ethylene oxide/propylene oxide copolymer are illustrated. These somewhat surprising results show that great care needs to be exercised when interpreting copolymer spectra for compositional analysis, even for copolymers with structurally similar monomers. This work also points out that further studies are needed to better understand and optimize spectral acquisition conditions for reliable copolymer compositional analysis by MALDI. Copyright © 2000 John Wiley & Sons, Ltd.

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