Evaluation of Natural Oil Adducts in Alkyd-Based Varnish Emulsion and Effect on Rowan (Sorbus torminalis) Wood

Abstract

In these days, preparation of eco-friendly wood surface coating agents has become important topic for environmental concerns. In this study, an alternative surface coating formulations was prepared with adducts of oils of apricot kernel (A), sesame (S) and grape seed (G) were mixed with oil modified alkyd-based synthetic varnish system. These emulsions were applied on Rowan (Sorbus  torminalis)  wood and exposed artificial UV irradiation. However, all emulsion coated samples show lower water sorptions regardless of conditions or level of treatments. Increasing adduct charges from 5.0% to 10% have not considerably effects for water sorptions. The reducing water sorption properties of 35.5%, 35.2% and 39.4% were obtained with 10% sesame oil-varnish coated samples of 10Sı and 10 Sıı in one- and two-time coatings and three-times coated samples of 5Sııı in 5.0% sesame oil-varnish emulsion coatings, respectively. Moreover, selected oil adducts into varnish had one and two point lowering effects on coated surface hardness (in 4H-5H levels).  The UV exposure seems to not much influence on surface hardness properties. The similar tendency were also observed for cross-cut resistance that marginally similar adhesion (scratch resistance)  for both control and UV exposured samples.  Increasing coatings and charge of apricot kernel oil in varnish emulsion looks like more effective than other varnish formulations, in terms of gloss stability. However, increasing adducts charges and UV radiation time, have more less similar effects on all coated and UV irradiated samples.