Weathering resistance of opaque PVDF-acrylic coatings applied on wood substrates

PVDF-acrylic opaque coating systems were applied onto two different wood species; Black spruce and White pine. Weathering resistance of these products was compared to the one of industrial water-based acrylic coatings used for exterior siding. ATR-FTIR results have shown that the PVDF portion of the coatings resist easily to the UV light, even at the extreme surface. At the opposite, the acrylic portion of the coatings was strongly affected by the UV light. This degradation has led to significant color change. Contact angles were also measured before and after the accelerated aging test in order to assess the recoatability of these coatings. Wettability was found to be slightly lower for the PVDF-acrylic coatings. The morphology of the different coating systems was finally assessed. Results have shown that the PVDF-acrylic coatings are strongly affected by the White pine resin exudation.

► PVDF-acrylic opaque coatings formulations were successfully prepared for wood substrates. ► PVDF-acrylic coatings presented a better resistance to weatherability than acrylic coating. ► PVDF is not affected by UV as per FTIR-ATR and XPS while acrylic is. ► PVDF-acrylic is negatively affected by wood resin exudation and extractive migration.