Abstract
While the autoxidation of linseed oil has been extensively studied, the
role of metal driers in catalyzing this process remains poorly
understood. Previous studies have demonstrated that Fourier Transform
Infrared spectroscopy (FT-IR) can be used to monitor the progress of
autoxidation during linseed oil drying. Typically, studies have focused
on a single absorption at 3010 cm-1 to determine the rate of
autoxidation. In this study, FT-IR spectra of linseed oil during
autoxidation were measured between 3800 and 700 cm-1 and fit to kinetic
models using global analysis, which provides more robust fitting than
prior methods. This study revealed that the drier catalyzed autoxidation
process can be best modeled as an A → B → C type reaction, with B
corresponding to a cis-trans conjugated intermediate previously
identified in model complex studies. These kinetic models further
revealed that for three Co driers the rate constants for the A → B and B
→ C reactions are identical within experimental error, suggesting both
reactions share a rate limiting step.