Today’s wood protection technology adopts copper-based chemical substances as the widely utilized material. Besides the adverse effect on human health, it also showed negative impact on organisms. To prevent this, a new method using of nano-sized chemical substances in wood preservation was being investigated. In this work, the effects of nano-clay and nano-sized particles of zinc oxide (ZnO), titanium oxide (TiO₂), aluminum oxide (Al₂O₃), and magnesium oxide (MgO) impregnation on the wood samples were investigated. Samples from Scots pine wood were impregnated with the nanoparticles. Besides that, samples with second impregnation of 10% polymethylmethacrylate (PMMA) were also prepared to investigate the improvement in wood properties. The physical and thermal properties of the samples were tested as well as biodegradation against the brown-rot fungus Coniophora puteana. Impregnation of nanoparticles slightly affect the water absorption properties, but second impregnation with 10% PMMA reduced the water absorption up to 20%. The lowest water absorption and the highest water repellencies after 336 h in water were determined on the samples treated with 10% nano-clay-PMMA and MgO-PMMA treatments. Water repellent efficiency and anti-swelling efficiency were also increased by addition of 10% PMMA with little decrement after longer soaking time. The highest ASE was found on the samples treated with 15% of nano-clay and zinc oxide nanoparticles (ZnO) with PMMA. Results also showed that impregnation of nanoparticles provides good protection against the tested fungi with the highest degradation was only 3.88% for Al₂O₃, compared to control sample with 20.26% weight loss. In conclusion, the applied nanoparticles are suitable substances to increase the durability of pine wood.

Solid wood can serve multifunctionality for energy savings in buildings. The study reveals the results of biodeterioration and degradation of solid Scots pine wood used to incorporate single or multicomponent fatty acid mixtures as bio-based phase change materials (BPCMs). The sapwood samples were impregnated with capric acid (CA), methyl palmitate (MP), lauryl alcohol (LA) and a mixture of coconut oil fatty acids and linoleic acid (CoFA-LA). The samples were tested against subterranean termites by an Italian species (Reticulitermes lucifugus), the wood boring beetle Hylotrupes bajulus and mold through a discoloration test. Tested against termites, the impregnated samples were significantly less susceptible to the attack than the controls, i.e., the tested BPCMs were resistant to R. lucifugus. The only test with MP terminated at the moment against H. bajulus showed positive results with no larvae surviving. The mold discoloration test revealed that the wood impregnated with CoFA-LA was identically susceptible to mold discoloration when compared to the control, nonimpregnated samples. This pioneer study verifies that solid wood employed for the encapsulation of BPCMs for building purposes can serve identically or somewhat better than similar wooden building elements regarding attacks of the above microorganisms and insects. Such multifunctional building elements will be tested further in a pilot scale building to characterize better the durability aspects of the new materials.

Thermally modified Scots pine samples were impregnated with lauric acid (LA) and myristic acid (MA) as phase change material (PCM) by vacuum process. The LA-MA mixture was prepared at a eutectic ratio of 66 to 34 wt%. Some properties of the wood samples such as hygroscopicity, mechanical, thermal energy storage (TES), and lab-scale thermo-regulative performance were investigated. Fourier transform infrared spectroscopy (FT-IR) was utilized to analyze the physicochemical characteristics of wood samples that underwent thermal treatment. The thermal degradation stability, cycling chemical/thermal reliability, and TES properties of the samples were assessed through TG (thermogravimetric analysis) and DSC (differential scanning calorimetry) analyses. The DSC results of thermally modified wood (TMW)/LA-MA samples showed good energy storage or release capacity with appropriate phase. These analyses also indicated that TMW samples infused with PCM exhibited reduced residue compared to the control samples. The experimental evaluation conducted on a small scale demonstrated that the PCM integrated within the wood effectively retains excess heat within the surrounding environment, thereby restricting heat dissipation. Moreover, the presence of PCM visibly decreased water absorption and enhanced the dimensional stability in wood. The impregnation with LA-MA improved mechanical properties of thermally modified wood despite the thermal modification that normally decreases mechanical properties.

Samples of Scots pine sapwood were treated with epoxidized linseed and soybean oils to improve decay, insect and termite resistance of wood. Non-epoxidized (raw) linseed and soybean oils were included as reference treatment in the study. In the epoxidation process, hydrogen peroxide was used to open double bounds, and acetic acid was added as a catalyst. Two retention levels, Ret A (80–140 kg m⁻³) and Ret B (170–270 kg m⁻³), two impregnation methods (full cell and empty cell) and emulsion technique were used. Samples treated with epoxidized oils had significantly lower mass losses than untreated samples while epoxidized oils showed higher mass losses than unepoxidized oils for Coniophora puteana and Trametes versicolor according to EN 113 for decay test. By adding boron, fungicidal properties were introduced to the treatment. All the vegetable oils showed 100% the mortality rate against larvae of Hylotrupes bajulus according to EN 47. Moreover, leached wood samples treated with oils also showed 100% larvae mortality. Additionally, termite testing based on EN 117 revealed 100% Reticulitermes lucifugus mortality for all leached oil treated samples.

Alkil Keten Dimer (AKD); ıslak mukavemet ve kâğıdın basılabilirlik özelliklerini değiştirdiği için çoğunlukla kağıt endüstrisinde kullanılır. AKD, odunun hidroksil gruplarıyla reaksiyona girer ve hidrokarbon zincirlerinin etkili bir şekilde esterleşmesine katkıda bulunur. Oduna AKD ilavesi ile boyutsal kararlılığın arttırılması hedeflenmiştir. Ayrıca çevre dostu olan bor bileşikleri ahşabın biyolojik zararlılara karşı korunmasında oldukça etkilidir. Ancak bor bileşikleri odundan kolayca yıkanabilmektedir. AKD/BA sinerjik etkisi ile birlikte bu olumsuz özelik giderilmeye çalışılıp odunun boyutsal kararlılığı arttırılmaya çalışılmıştır. Bu çalışmada AKD (%5, %10, %18) ve borik asit (%3 BA) kombinasyonları ile emprenye edilmiş sarıçam (Pinus sylvestris L.) odun örnekleri kullanılmıştır. Örneklerin su alma ve boyutsal kararlılıkları ile mekanik özellikleri belirlenmiştir. Su alma ve boyutsal kararlılık testi için AWPA E4, liflere paralel basınç direnci için TS 2471 standartları kullanılmıştır. Elde edilen sonuçlara göre AKD/BA kombinasyonunun daha düşük su alma oranına sahip olduğu görülmüştür. Mekanik testte AKD ve BA sinerjik etkisi ile birlikte örneklerin mekanik özellikleri bir miktar iyileşmiştir.