Heat-treatment effects on wood durability outdoors and performance of polymeric coatings—adhesion and wood-water interactions
Akbar Mastouri, Mohammad Azadfallah, Hadi Gholamiyan, Mariaenrica Frigione
22 ottobre 2025 · Journal of Adhesion Science and Technology
This publication is not marked as Open Access. The full text may require access through the publisher.
Summary
No reviewed summary yet. Read the abstract below or open the original publication.
Abstract
The outdoor durability of wood coatings depends not only on the polymeric phase, but also significantly on the physical properties of the wood substrate. This study assesses the exterior durability of coatings applied to heat-treated (185 °C) and untreated spruce wood, emphasizing the role of substrate characteristics under real-world outdoor aging. The properties of heat-treated (HT) wood, in comparison to control (i.e. untreated) samples, were investigated during natural exposure for 6 months: water absorption, surface wettability, air permeability, and equilibrium moisture content (EMC). The adhesion strength (AS) dynamics of solvent-borne polyurethane (PU) coatings to wood substrates was assessed via pull-off testing, considering the effects of heat treatment and natural weathering. A decrease (−15%) in the AS of PU-coating to HT wood was observed, attributed to poor wettability and reduced permeability of wood through thermal modification. However, heat treatment showed better performance in terms of adhesion and coating quality in outdoor conditions, where the AS loss for HT and control wood was −18% and −43%, respectively. The development of amorphous structures and reduction in cellulose degradation temperature (DTG-TMax) due to outdoor weathering, along with the superior performance of HT wood, were confirmed through thermogravimetric analysis (TGA, DTG). Overall, the water-repellency, thermal-stability, low hygroscopicity, and limited permeability of HT wood minimize wood distortion/degradation during aging and ensure the long-term stability of applied coatings in service. Hence, the synergy between heat treatment and protective coating can be considered an effective strategy for wood materials. Nonetheless, a wetting modification to the HT spruce wood surface is recommended prior to the painting or finishing process, to achieve excellent outdoor durability.
Abstract as supplied by the source. Full text may be restricted by the publisher.
Related publications
Predicting the mechanical properties of sawn timber: Basic non-destructive tools applicable to Norway spruce sawlogs
1 set 2026 · Rostislav Berezjuk, Matěj Šimek, Robert Mařı́k et al. · Central European Forestry Journal
Mechanical properties of sweet chestnut sawn wood and glulam performance
15 mag 2025 · Carlos Eduardo de Jesus Martins, Cláudio Ferreira, Sandra R. S. Monteiro et al. · European Journal of Wood and Wood Products
Moisture-induced timber joining - Utilizing the hygroscopicity and shape-memory effect of wood resulting in dimensional change in a prefabricated wood-only, self-built, sawn timber system for affordable housing in Colombia
1 mar 2024 · Max Salzberger, Juan Sebastian Cruz Rojas, Gilbert Koskamp · Research Square
Effects of thermal and chemical treatments on colourimetric characteristics of young African mahogany and eucalypts wood for sawn timber production
3 lug 2026 · Joyce de Almeida Pinto, Juarez Benigno Paes, Graziela Baptista Vidaurre et al. · Southern Forests a Journal of Forest Science