•Furfurylation was demonstrated for the first time to be highly efficient for bamboo modification due to the high permeability of furfural alcohol (FA).•The modified bamboo was found to be highly ...resistant to mold, decay fungi and termites with low FA weight percentage gain (WPG).•The mechanical properties of furfurylated bamboo could be moderately enhanced at low FA concentrations.
Bamboo is an important sustainable material for construction industry due to its combined advantages of easy availability, fast renewability, and excellent mechanical performance. However, its low biological durability and poor treatability limit its use for structural and outdoor building material. In this study, highly durable bamboo materials were prepared through a facile modification process called bulk furfurylation for the first time. The modified bamboo was found to be highly mold resistant and exhibited strong resistance to decay fungi and termites with a furfuryl alcohol (FA) weight percentage gain (WPG) as low as 10%. A strong positive correlation was detected between WPG and termite resistance, but not for mold or decay resistance. The mechanical properties of the furfurylated bamboo were moderately enhanced at low FA concentrations and were much less affected by curing temperature and time. Based on these results, it is concluded the furfurylated bamboo would have wide application in construction.
This study's aim is to investigate the effect of ionizing rays such as gamma rays on the natural Durability and morphology of wood plastic composites against fungus (Trametes versicolor) and ...(Gloeophyllum trabeum), white rot, and brown rot respectively. Abies wood flour with weight ratios of 20% and 40% is mixed with three different polypropylene melt flow indices (H, M, and L) and maleic anhydride polypropylene as a compatibilizer material. The mixing process is performed by a Brabender mixer. Test specimens are made using a press machine. The test specimens are exposed to rainbow and brown fungus for one month at a temperature of 25 ± 1 °C and humidity of 65 ± 5% under EN113. Then, the percentage of mass reduction, water absorption, and thickness swelling on the samples were investigated. A scanning electron microscope (SEM) is used for the morphology of the composites. The results show that the mass reduction percentage, water absorption, and thickness shrinkage are reduced by irradiating gamma rays at a dose of 25 kGy and increasing the melt flow index on wood plastic composite pieces. Decreasing the percentage of wood flour reduces the severity of rot, water absorption, and thickness swelling of the samples. The effect of MFI on the natural durability of wood plastic composites is greater than the effect of gamma rays. The results showed that the gamma radiation effect in reducing the weight of white and brown fungus decay in LMFI, MMFI, and HMFI parameters in the composite sample with 40%, the difference between the irradiated and non-irradiated samples is statistically significant at 95% confidence level but for composite with 20% wood flour, the difference in the irradiated and non-irradiated samples in weight loss is not statistically significant at the 95% confidence level. Also, the results showed that the effect of gamma radiation on the amount of water absorption and thickness shrinkage in the mentioned parameters in the 20% and 40% wood flour composite is statistically significant at the 95% confidence level, and there is a significant difference between the irradiated and non-irradiated samples. Also, the uniformity of the micrographs obtained from SEM showed that by gamma irradiation to the wood plastic composite, the reflection between the wood fibers and the polymer improved.
•The effect of gamma-ray on fungal rot.•The effect of gamma-ray on the natural Durability of wood plastic.•The effect of gamma-ray on the morphology of wood plastic.
The fast-growing species of Populus deltoides is of significant commercial importance to the Indian wood merchants. Despite its abundant availability and better treatability, the use of P. deltoides ...is limited due to its perishable nature. Heat treated and chemically modified Populus deltoides L. was thus explored for dimensional stability and biological durability to commercialise its use. Chemical modification was performed using a combination of citric acid and sodium hypophosphite. Heat treatment was done in a laboratory oven in air at 140 °C for 8h. Both chemically modified and heat-treated samples exhibited improvements in dimensional stability and biological durability in comparison to the untreated control sets. Chemical modification resulted in better dimensional stability. Anti-swelling efficiency of Populus deltoides was 2-2.5 times more for the chemically modified set compared to heat treatment in both radial and tangential directions. Chemically modified set became significantly more resistant to biodeterioration showing 5 times less mass loss by termites, whereas controls and heat-treated sets returned loss percentages which were comparable. Soil block bioassay with Trametes versicolor (TV) exhibited mass loss of 9.46 % for chemically modified samples, 40.26 % for heat treated samples and 50.02 % for the untreated controls, respectively. Rhodonia placenta (OP) followed a similar trend with mass loss of chemically modified set being 5.72 % and heat-treated set being 37 %, respectively, with the controls showing 43.85 % mass loss. Mass loss exhibited by the heat-treated samples were less than the controls, but the values suggested that heat treatment at 140 °C for 8 h failed to impart any substantial resistance against rotting fungi and termites.
Brzorastuća vrsta Populus deltoides ima veliku komercijalnu važnost za indijske trgovce drvom. Unatoč velikoj dostupnosti i dobroj obradivosti, upotreba drva P. deltoides ograničena je zbog njegove slabe trajnosti. Stoga je radi bolje komercijalizacije drva Populus deltoides L. istražen utjecaj toplinske i kemijske modifikacije na njegovu dimenzijsku stabilnost i biološku trajnost. Kemijska modifikacija provedena je kombinacijom limunske kiseline i natrijeva hipofosfita. Toplinska modifikacija u trajanju od osam sati obavljena je u laboratorijskom sušioniku pri 140 °C, uz prisutnost zraka. Kemijski i toplinski modificirani uzorci drva pokazali su bolju dimenzijsku stabilnost i biološku trajnost od nemodificiranih kontrolnih uzoraka. Kemijska modifikacija rezultirala je i većom dimenzijskom stabilnošću. Učinkovitost u sprečavanju bubrenja drva Populus deltoides bila je 2 – 2,5 puta veća u kemijski modificiranih uzoraka nego u toplinski modificiranih uzoraka, i to u radijalnome i tangencijalnom smjeru. Kemijski modificirani uzorci drva postali su znatno otporniji na biološko propadanje i pokazali su pet puta manji gubitak mase pri djelovanju termita nego toplinski modificirani i nemodificirani uzorci. Test s Trametes versicolor (TV) pokazao je gubitak mase od 9,46 % za kemijski modificirane uzorke, 40,26 % za toplinski modificirane uzorke i 50,02 % za nemodificirane uzorke. Za test s Rhodonia placenta (OP) uočen je sličan trend gubitka mase, koji je za kemijski modificirane uzorke iznosio 5,72 %, za toplinski modificirane uzorke 37 %, a za nemodificirane uzorke 43,85 %. Gubitak mase toplinski modificiranih uzoraka drva bio je manji od gubitka mase nemodificiranih uzoraka, ali su vrijednosti pokazale da se toplinskom modifikacijom pri 140 °C tijekom osam sati nije uspjela postići značajna otpornost protiv gljiva truležnica i termita.
High-temperature vapour-phase acetylation (HTVPA) is a simultaneous acetylation and heat treatment process for wood modification. This study was the first investigation into the impact of HTVPA ...treatment on the resistance of wood to biological degradation. In the termite resistance test, untreated wood exhibited a mass loss (MLt) of 20.3%, while HTVPA-modified wood showed a reduced MLt of 6.6–3.2%, which decreased with an increase in weight percent gain (WPG), and the termite mortality reached 95–100%. Furthermore, after a 12-week decay resistance test against brown-rot fungi (Laetiporus sulfureus and Fomitopsis pinicola), untreated wood exhibited mass loss (MLd) values of 39.6% and 54.5%, respectively, while HTVPA-modified wood exhibited MLd values of 0.2–0.9% and −0.2–0.3%, respectively, with no significant influence from WPG. Similar results were observed in decay resistance tests against white-rot fungi (Lenzites betulina and Trametes versicolor). The results of this study demonstrated that HTVPA treatment not only effectively enhanced the decay resistance of wood but also offered superior enhancement relative to separate heat treatment or acetylation processes. In addition, all the HTVPA-modified wood specimens prepared in this study met the requirements of the CNS 6717 wood preservative standard, with an MLd of less than 3% for decay-resistant materials.
The aim of this study was to investigate the biological durability of particleboard, containing silver nanoparticles (Ag-NPs) and copper nanoparticles (Cu-NPs) to Trametes versicolor, white-rot ...fungus of hardwoods. NPs were mixed and sprayed with applied resin, to cover wood particles volumetrically. Bio-deterioration of specimens was measured through average mass loss after 4-16 weeks of exposure to T. versicolor. The results displayed a significant impact of Ag-NPs and Cu-NPs on the antifungal resistance of particleboard. The highest resistance to fungal attack is experienced by sample containing 15% Ag-NPs with the mass loss of 0.9% for 4 weeks to 3.24% after 16 weeks of exposure to T. versicolor which was classified as a very durable sample. Maximum mass loss of 45.5% was observed for the control specimens after 16 weeks. The presence of Ag-NPs and Cu-NPs on the wood particle surface was verified by the Energy-Dispersive X-ray Spectroscopy. Scanning Electron Microscopy analysis confirmed the uniform distribution of NPs in bondline covered the surface of the wood particles properly, which seems to be an impressive barrier to fungal attack by inhibiting fungal hyphae growth. Because of the high thermal conductivity of metallic NPs, internal bonding properties of particleboard containing NPs were improved.
Knowledge about the resistance of wood-polymer composites (WPCs) to biological attack is of high importance for purpose-oriented use in outdoor applications. To gain this knowledge, uniform test ...methods are essential. EN 15534-1 (2018) provides a general framework, including the recommendation of applying a pre-weathering procedure before the biological laboratory tests. However, the procedure's manner is not specified, and its necessity assumes that a durability test without such pre-weathering will not produce the structural changes that occur during outdoor use. To verify this assumption, this study examined the influence of natural, ground-level pre-weathering on the material properties of different WPC variants, which were tested at intervals of six months in four durability tests under laboratory conditions in accordance with EN 15534-1 (2018). Weathering factors were calculated from determined characteristic values such as mass loss, and loss in moduli of elasticity (MOE) and rupture (MOR). The weathering factors based on mechanical properties tended to decrease with increasing weathering duration. The expected negative influence of pre-weathering on these material properties was thus not confirmed. The weathering factors based on mass loss were subject to high variation. No significant effect of pre-weathering on mass loss due to fungal attack became evident. Overall, the necessity of a pre-weathering step in biological durability tests shall be questioned based on the presented results.
The effect of wollastonite nanofibers (NW) on biological resistance of particleboard, made from wood chips and chicken-feather fibers (CF), against Antrodia vaillantii was studied. 10% of NW, as well ...as 5 and 10% of CF, were applied to the particleboard-matrix based on the dry weight of wood chips. Then, as a complimentary study, 10% wood fibers were also added to the wood chips; totaling, 10 mixing treatments. Specimens were prepared and mass loss (ML) values were measured in accordance with the EN 113 specifications. Results indicated that the highest ML (37%) occurred in the control treatment without NW- or CF-content; the lowest ML was seen in panels with 10% of NW, CF, and wood fibers (2.5%). NW substantially decreased ML in all mixing ratios. CF also showed a significant decreasing effect on ML. No significant correlation was found between ML values with any of physical and mechanical properties; however, high significant correlations were found between most of the mechanical properties. It is concluded that NW may be considered an effective filler in wood-composite industry to increase the durability against fungal attack; however, more studies should first be conducted on different fungi and wood and wood-composite materials to finalize this conclusion.
•Nanowollastonite (NW) hinders degradation of particleboard (PB) by Antrodia vaillantii.•Chicken feathers can replace part of the wood chips in particleboard panels.•Chicken feathers also decrease mass loss in PB when it is exposed to A. vaillantii.•NW is not a hazardous material and can safely be used in wood-composite panels.
Durability-based designs with timber require reliable information about the wood properties and how they affect its performance under variable exposure conditions. This study aimed at utilizing a ...material resistance model (Part 2 of this publication) based on a dose–response approach for predicting the relative decay rates in above-ground situations. Laboratory and field test data were, for the first time, surveyed globally and used to determine material-specific resistance dose values, which were correlated to decay rates. In addition, laboratory indicators were used to adapt the material resistance model to in-ground exposure. The relationship between decay rates in- and above-ground, the predictive power of laboratory indicators to predict such decay rates, and a method for implementing both in a service life prediction tool, were established based on 195 hardwoods, 29 softwoods, 19 modified timbers, and 41 preservative-treated timbers.
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