The influence of bipyridine on the drying of alkyd paints: a model study

New manganese-based catalyst systems for alkyd paint drying

“…Then 160 l of the mixture was spread in a thin layer on the sample holder (resulting in approximately 0.3 mm layer thickness) to undergo time-resolved infrared measurements. This layer thickness was chosen to prevent the limitation of dioxygen diffusion from influencing the result [11].…”

“…However, several reports have been published describing the possible carcinogenicity of cobalt salts and cobalt complexes [9,10]. Some commercial paint formulations contain manganese carboxylate as primary drier instead of cobalt, however, these do not have the same performance as cobalt [7,11,12]. This has initiated a search to find alternatives for cobalt complexes as drying catalysts in alkyd paint [2,[11][12][13][14].…”

“…Some commercial paint formulations contain manganese carboxylate as primary drier instead of cobalt, however, these do not have the same performance as cobalt [7,11,12]. This has initiated a search to find alternatives for cobalt complexes as drying catalysts in alkyd paint [2,[11][12][13][14]. Recently, our group reported the manganesebased catalyst system [Mn(acac) 3 ]/bpy (bpy = 2,2 -bipyridine), which exhibits a very high activity in the oxidation of unsaturated fatty acids [13].…”

“…Because of the complex nature of real alkyd mixtures, a model reaction has been developed using ethyl linoleate (EL) as a substrate for rapid screening of new possible catalysts; the different activities can be compared using time resolved FT-IR and size exclusion chromatography [11,12]. Herein, we report the use of manganese salts in combination selected Schiff-base ligands (L1-L4, Scheme 2) as catalysts in the model oxidation reaction of EL.…”

“…The kinetics of fatty acid oxidation can be studied using time-resolved FT-IR spectroscopy [20,21], and this method has been shown to be quite useful in the screening of the activity of new potential catalysts [11]. The disappearance of the cis C CH vibration at 3010 cm −1 is especially suitable to follow the disappearance of the substrate in time.…”