Comparison of Some Physical and Mechanical Properties of Waterborne Acrylic Coating Systems Containing Commercial UV Absorbers and Tree Bark Extracts

Abstract

Aim of study: The aim of this study was to compare solid content, dry film thickness, and adhesion strength of different tree bark extract based and a commercial UV absorber. Materials and methods: Waterborne acrylic-based coating systems containing 5 different tree bark extracts (maritime pine, Calabrian pine, black pine, alder, fir) and a commercial UV absorber (Tinuvin 400 DW) were applied to 2 different wood species; Scots pine (Pinus sylvestris L.) and beech (Fagus orientalis L.). The dry-film thicknesses of the coatings were measured with light microscopy. The adhesion strength of the coatings was determined to investigate the bonding ability of the coatings with wood surfaces. The solid contents of the coatings were also determined. Main results: Permeability is an important parameter for dry-film thickness and adhesion strength. Wood species also influenced the dry-film thickness as well as adhesion strength. The dry-film thicknesses of the coatings containing bark extracts were higher than those with commercial UV absorbers. Similarly, the solid content of the coating containing maritime pine bark extract was found to be the highest. Highlights: The dry-film thickness and adhesion strength of waterborne acrylic coatings on wood substrate seem to be affected by addition of tree bark extracts.