DURABILITY IN OUTDOOR CONDITIONS OF COATING SYSTEMS BASED ON WATERBORNE ACRYLIC RESIN WITH COMMERCIAL UV ABSORBER AND TREE BARK EXTRACT

Abstract

Environmentally friendly new wood preservative surface materials were developed to protect the wood surface against outdoor conditions. The durability performance of different types of waterborne acrylic resin with bark extract used as coatings on a wood surface exposed to outdoor conditions was investigated. Scots pine and Oriental beech surfaces were coated with three different waterborne acrylic resin coatings. Bark extracts from two different trees (fir and black pine) and a commercial UV absorber were used in the acrylic resin coating formulations. The durability of the coatings containing these bark extracts were compared with that of the coating with a commercial UV absorber. The wood samples coated with the test and control coatings were exposed to the QUV test in laboratory conditions. The surface colour and roughness changes on the wood samples coated with the test coatings and exposed to the accelerated weathering test were compared with the control samples. Microscopic images were taken, and the coating thicknesses of the control and test samples prepared before the outdoor test were determined. The results showed that the protective effect of the acrylic coating system containing fir bark extracts in QUV test conditions over 2016 h was similar to that of the coating containing commercial UV absorbers. However, while the fir bark extract's antioxidant effect positively affected the beech wood to increase durability in outdoor conditions, it had a lower preservative effect on the pine wood.