Eco friendly self stratifying powder coatings
Reseachers have presented self-stratifying powder coatings based on an eco-friendly and solvent-free epoxy/silicone technology for simultaneous corrosion and weather protection.
The powder forms of the silicone and epoxy resins were mixed either by dry-blending or co-melt-mixing processing method, and blends were electrostatically applied onto steel sheets and cured. Self-stratification of cured coatings with a thickness of 100 ± 30 μm occurred and was investigated by an adopted ATR-FTIR method and consolidated SEM-EDX and X-ray photoelectron spectroscopy.
Good adhesion
It was corroborated that the dry-blending of methyl substituent silicone resin with the high and medium molecular weight epoxy resins at a 1/3 mass ratio (silicone/epoxy) leads to a complete stratification structure, having the silicone phase located on the top of the coating and the epoxy phase towards the steel surface, resulting in good adhesion. 3/1 mass ratio of the silicone/epoxy blends led to the dispersion of epoxy droplets into the silicone matrix and 1/1 mass ratio, showed lateral phase separation morphology.
The study has been published in Progress in Organic Coatings, Volume 161, December 2021.
