No abstract

No abstract

No abstract

No abstract

Aging of motor oil is characterized by diverse NMR methods to get insight into the chemical processes which occur during aging. Already one-dimensional 1H and 13C spectra reveal the relevance of chemical aging also with respect to the mechanical behavior of oils. As NMR is a quantitative analytical method, the absolute chemical changes can be observed and quantified. In addition, the spectral interpretation in terms of chemical composition is confirmed and deepened by two-dimensional 1H–1H, 1H–13C, and 1H–15N correlation spectra, as well as diffusion and relaxation experiments. The different NMR results are discussed and interpreted to obtain a thorough picture about aging processes of motor oils.