Investigation of cobalt drier retardation

The retardation of cobalt driers was investigated using a commercial alkyd. The onset of curing and crosslink density of the alkyd was used to evaluate four cobalt complexes, Co(acac)2, Co(acac)3, Co(OH)2, and Co(NH3)6Cl3. The catalytic activity of these complexes were compared to cobalt naphthenate. Differential scanning calorimetry and dynamic mechanical thermal analysis data were used to determine acceleration or retardation of the autoxidation drying mechanism. The Co(acac)2 accelerates the process in comparison to Cobalt(II) naphthenate, whereas the three other complexes seem to retard the process.