Eco-friendly Wood Research Articles

Cationic gemini compounds with antifungal activity and wood preservation potentiality

Three gemini compounds were synthesized and characterized in the search of an alternative eco-friendly wood preservative. Synthesis was carried out from N,N-dimethylamines and 2-O-acetyl-1,3- dichloropropane as linker molecule. All the synthesized molecules were adequately purified and characterized by TLC, GC, FT-IR and NMR. Their tensioactive properties were determined. All three efficiently lowered the surface tension in aqueous solutions with critical micelle concentrations ranging from 0.53 to 1.34mM. Their antifungal activities were evaluated from a broth dilution test against four yeasts and two filamentous fungi and were compared to commercially available references: Fluconazole and TCMTB (2-thiocyanomethylthiobenzothiazole). All gemini compounds displayed good antifungal activity; particularly, the gemini derived from N,N-dimethyldodecylamine, with even better performance than Fluconazole against Saccharomyces cerevisiae, Aspergillus niger and Alternaria sp., and than TCMTB against the last one. The environmental impact of the gemini compound that showed the highest antifungal activity was analyzed through ecotoxicity tests, using Chlorella vulgaris and Daphnia magna as model organisms. It was several orders of magnitude less toxic than TCMTB. Finally, wood preservation efficacy studies were carried out on pine (Pinus ponderosa) samples. Results demonstrated accomplished resistance against brown rot fungi, comparable to a widespread commercial hydrosoluble preservative.

A Novel Eco-Friendly Wood Adhesive Composed by Sucrose and Ammonium Dihydrogen Phosphate.

Development of a bio-based wood adhesive is a significant goal for several wood-based material industries. In this study, a novel adhesive based upon sucrose and ammonium dihydrogen phosphate (ADP) was formulated in hopes of furthering this industrial goal through realization of a sustainable adhesive with mechanical properties and water resistance comparable to the synthetic resins used today. Finished particleboards exhibited excellent mechanical properties and water resistance at the revealed optimal adhesive conditions. In fact, the board properties fulfilled in principle the requirements of JIS A 5908 18 type standard, however this occured at production conditions for the actual state of development as reported here, which are still different to usual industrial conditions. Thermal analysis revealed addition of ADP resulted in decreases to the thermal thresholds associated with degradation and curing of sucrose. Spectral results of FT-IR elucidated that furanic ring chemistry was involved during adhesive curing. A possible polycondensation reaction pathway was proposed from this data in an attempt to explain why the adhesive exhibited such favorable bonding properties.

Evaluation of adhesion properties of blends of cottonseed protein and anionic water-soluble polymers

There is increasing interest in agro-based, biodegradable and eco-friendly wood adhesives as partial replacements for petroleum-based adhesives. In this work, we studied the adhesion of cottonseed protein isolate (CPI) blended with several anionic water-soluble polymers. Anionic vinyl polymers studied included poly(acrylate), poly(acrylate-co-acrylamide), poly(vinyl sulfate), poly(vinyl sulfonate), and poly(vinyl phosphonate). Anionic polysaccharides studied included three types of carrageenan, carboxymethyl cellulose (CMC), low-methoxy pectin, alginate, and chondroitin sulfate. In general, the adhesive strength of CPI increased with the addition of anionic polymer up to a certain level and then decreased with further polymer addition. Different anionic polymers showed different enhancements. The best result for vinyl polymers was observed for the CPI/poly(vinyl sulfate) blend, which exhibited a 30% improved dry strength over CPI alone. The best results for the polysaccharides were obtained for the CPI/CMC and CPI/pectin blends, with improvements in dry adhesive strength over the CPI control of 66% and 50%, respectively. The CPI/CMC and CPI/pectin blends also showed improved hot water resistance. These findings suggest that the CPI/anionic polymer blends might be useful components in biobased wood adhesive formulations.

Production of oil palm (Elaeis guineensis) fronds lignin-derived non-toxic aldehyde for eco-friendly wood adhesive

Lignocellulosic materials can significantly contribute to the development of eco-friendly wood adhesives. In this work, glyoxal-phenolic resins for plywood were prepared using organosolv lignin, which was isolated from black liquor recovered from organosolv pulping of oil palm fronds (OPF) and considered to be an alternative to phenol. Glyoxal, which is a dialdehyde obtained from several natural resources, was used as substitute for formaldehyde. The structure of organosolv lignin and the resins were characterized by FTIR and NMR, and for thermal stability by TGA and DSC. The resins were further studied for their viscosity, pH, solids content and gel times. The resins performance as wood adhesive was further established from mechanical test in terms of tensile strength and modulus of elasticity (MOE) to obtain the optimum ratios of organosolv lignin, which replaces phenol in organosolv lignin phenol glyoxal (OLPG) resins. The adhesive composition having 50% (w/w) of phenol substituted by organosolv lignin, termed as 50% OLPG showed highest adhesive strength compared to phenol formaldehyde (PF) commercial adhesive.

Wood Property Improvement of Siberian Pine by Combination of Boric Acid Impregnation and In-Situ Polymerization of Ԑ-Caprolactone

Wood is an excellent engineering material with its light weight and high mechanical properties. However, it is susceptible to biodegradation due to its hygroscopic nature and chemical composition that limits both its indoor and outdoor usage. Boron compounds which are known as eco-friendly wood preservatives have limited utility at outdoor conditions since they are easily leached out from wood by water. The aim of this study is to prevent boron leaching by creating a polymer network that encapsulates boron compound inside the wood cell walls, thus decay resistance, dimensional stability and water repellence are improved. In the study, Siberian pine samples were impregnated with 1% boric acid in DMF(N,N-Dimethylformamide) and further e-caprolactone monomer (1% SnOct2 as initiator) mixture for further in-situ polymerization were carried out in the oven at 150°C for 3 hours. Prior to decay testing, leaching test was conducted in order to evaluate any loss in effectiveness in decay resistance against to C. puteana and C. versicolor attack due to possibility of boron leaching from wood. The results showed that leached samples had lower weight loss than unleached samples after C. puteana attack, however, the weight loss by C. versicolor attack increased in leached samples. Decay resistance of treated samples was found to be 7-99% in comparison with references. Boric acid and polymer combination increased dimensional stability (25% ASE), and water repellence (15%) of wood compared to references without deformation. This method showed that curing may be an alternative for wood modification with in-situ polycaprolactone polymerization in order to use hazardous solvent media for polymerization.

Potential use of coconut shell pyrolytic oil distillate (CSPOD) as wood protectant against decay fungi

Considerable interest has been developed on environmentally friendly technologies for wood protection. The current investigation focused on the development of an ecofriendly wood preservative formulation from coconut shell pyrolytic oil distillate (CSPOD). Rubberwood specimens treated with CSPOD were exposed to brown rot and white rot fungi and the efficacy was assessed in terms of percentage weight loss and FTIR spectra analysis. Treated samples showed significant reduction in weight loss when compared to control samples indicating the efficacy of the distillate. FTIR spectra further confirmed the ability of the distillate to protect wood against decay fungi. Phenolic compounds were the main components in the distillate as evidenced by GC–MS analysis. The presence of phenolic compounds in the distillate has given the significant decay resistance to the treated wood against both white rot and brown rot fungi. Hence, coconut shell pyrolytic oil distillate has the potential to be developed into a wood preservative formulation.

Physicochemical characterization of leaf extracts from Ocotea lancifolia and its effect against wood-rot fungi

This study is designed to evaluate the physicochemical properties and the decay resistance of leaf extracts obtained from a native Brazilian tree Ocotea lancifolia. Ethanol was used to obtain crude extract from milled leaves, which was further partitioned with ethyl acetate and butanol achieving two phenolic-rich fractions. Furthermore, wood veneers were impregnated with crude extract and its fractions (at 1 and 4%), and evaluated against two wood-destroying fungi. Firstly, Fourier transform infrared and thermogravimetric analysis confirmed chemical differences on structure, stability and purity of the evaluated extract samples. Crude extract presented lower total phenolic content (178 mg GAE/g dried sample) and lower antioxidant activity than its fractions. Moreover, the fractions showed 360–405 mg GAE/g dried sample and a high scavenging effect (IC50 < 0.75 mg/mL). Chromatographic analysis revealed the presence of quercetin-derived monoglucosides in all samples, such as quercetin-3-O-rhamnoside (∼20–22% in crude extract and ethyl acetate fraction) and quercetin-3-O-glucoside in butanolic fraction (20.71%). Crude extract and ethyl acetate fraction at 4% were the most effective treatments to reduce the action of two wood-rot fungi (mass loss < 8%). Overall, leaf extracts from O. lancifolia can provide a renewable source of antioxidants and eco-friendly wood preservatives.

Effect of Thermal & Alkali Treatment on Pterocarpus Angolensis (Mukwa) Wood Flour

Environmental friendly pre-treatment of fibre has been lately adopted by many researchers worldwide but not fully understood. Although various chemical modifications of fibre through several chemical treatments have been explored, but less has been done on lower sodium hydroxide (NaOH) concentrations. This paper investigated the effect of thermalization at 115 C and lower NaOH of concentrations (1, 3 and 5) effect on mukwa wood flour as a way of minimizing chemical impact on possible manufacturing of eco-friendly wood polymer composites (WPC). Weight loss analysis was carried out to evaluate the effect of thermalization and alkalization modification. X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to characterize the untreated and treated mukwa wood flour. The results showed significant surface modification thereby improving fibre characteristics as impurities (hemicellulose, lignin and other non-cellulosic substances) were removed.

Investigation of Leaching Performance of Wood Materials Colored with Walnut Husk

The purpose of this study to develop an eco-friendly wood stain alternative to synthetic dyes and to determine the desorption on wood surfaces. For this purpose; wood blocks was prepared from Turkish oriental beech ( Fagus orientalis Lipsky), Scots pine ( Pinus sylvestris L.) , oak ( Quercus petraea spp) , and walnut ( Juglons regia L.) . Plant dyestuff was extracted from the Walnut husk by using ultrasonic assisted method. For mordants, ferrous sulfate (Fe 2 (SO 4 ) 3 .7H 2 O) , aluminum sulfate (KAl 2 (SO 4 ) 3 .18H 2 O) , copper sulfate (CuSO 2 .5H 2 O) , and vinegar (CH 3 COOH) were chosen and applied to wood blocks with immersion (classic) and immersion+ultrasonic assisted methods. To determine the stability of paint, the effect of such parameters as the medium pH (5, 7 and 9), temperature (22 and 40 °C), agitating speed (10 and 30 rpm) in leaching test was studied. Result showed that, generally aluminum sulfate and ferrous sulfate performed well desorption were reduced the desorption on all wood species surfaces.

An eco-friendly wood adhesive from soy protein and lignin: performance properties

The aim of this study was to improve the water resistance of a soybean meal-based adhesive with a low-cost lignin-based resin (LR).

Natural coloration of wood material by red beetroot (Beta vulgaris) and determination color stability under UV exposure

This study is aimed to develop an eco-friendly wood stained extracted from beetroot (Beta vulgaris) and determine the color stability of this stain to UV light irradiation. Natural dyestuff were extracted from beetroot by ultrasonic-assisted method and prepared from aqueous solution with ferrous sulphate, aluminum sulphate, copper sulphate and vinegar mordant mixes. Scots pine (Pinus sylvestris), oriental beech (Fagus orientalis), oak (Quercus petraea) and walnut (Juglans regia) wood specimens were used for the study. After treatment with stain, wood specimens were exposed to UV irradiation for periods of 50, 100 and 150 hours. Results showed that the color change values for all wood specimens colored with beetroot extract had better performance compared to synthetic dye. Beetroot extracts may be used as an upper surface dyestuff for indoor application and toys. Therefore, alternative to synthetic dyes more economical and eco-friendly, wood paints may be developed.

Strategies of Eco-Friendly Stimulant Use Policy in Perum Perhutani, Indonesia

The use of strong acid H2SO4 stimulant (AN-ORGANIC) in effort to improve resin results in Perum Perhutani area is proved not safe for workers and the environment. On the other hand, eco-friendly stimulants such as ETRAT has been used in most areas of Perhutani and wood vinegar were developed. This research is aimed to identify strategies of eco-friendly stimulant use policies in tapping pine. Data collection was conducted through in-depth interviews to several informants consisting of tapper community, foreman, Ranger, Head of RPh, Head of KPH, Deputy head of KPH, NTFPs section chief, Head and deputy chief Production Unit. Selection of informants is carried out purposively that is derived from pine resin producing areas 3 largest in Perum Perhutani (KPH Banyumas West, KPH Kediri and KPH Sukabumi). The results showed that the strategy of eco-friendly stimulant use policies could be adopted by Perhutani with four strategies: 1) Increase the use of eco-friendly stimulant by utilizing eco-friendly wood vinegar-based stimulant produced by Perhutani; 2) Implement eco-friendly wood vinegar-based stimulant produced by Perhutani to press the price of an expensive eco-friendly stimulant; 3) Increase the use of eco-friendly and safer stimulant innovation to convince Perhutani so that eco-friendly stimulant can be accepted and used extensively; and 4) Press eco-friendly stimulant prices through innovations that could be accepted usage in Perhutani thoroughly.

Wood Preservation Based on Neem Oil: Evaluation of Fungicidal and Termiticidal Effectiveness

Abstract This research examined oil from the neem tree (Azadirachta indica A. Juss.) for its potential as an eco-friendly wood preservative. In contrast to expectations from the literature, according to which neem oil should be effective against insects and fungi, neem oil performed poorly as a preservative for Pinus radiata D. Don wood, which suffered significant mass losses in the bioassays. Using standard experimental procedures from the wood preservation industry, concentrations of 0.01, 0.1, 1.0, 2.5 and 5.0 percent neem oil in white spirit were bioassayed against five species of decay fungi. Additionally, concentrations of 0.01, 0.1 and 1.0 percent neem oil were bio assayed against two species of termites. It is concluded that neem oil can only be useful as a wood preservative if new, optimized formulations are sought, probably exploiting synergy with cobiocides.

Structure and antioxidant activity of diarylheptanoids extracted from bark of grey alder (Alnus incana) and potential of biorefinery-based bark processing of European trees

Abstract The bark of trees has a big potential as a source of green chemicals. The aim of the present work was to valorise the potential of deciduous tree species with this regard. Three widely spread trees in Europe (grey alder, ash tree, aspen) were in focus as a source of polyphenols, and the yields of polyphenolic compound in the extracts were considered as evaluation criteria. The highest yields of hydrophilic extractives were found in barks of grey alder and aspen (36.8 and 22.9%, respectively). In the former, the highest antioxidant activity was found towards free radicals (DPPH• and ABTS•+) and superoxide anion radical. Open chain diarylheptanoids, mainly oregonin, were identified as the major constituents of the grey alder hydrophilic extract. In addition to oregonin, the presence of 2 linear diarylheptanoids [platyphylloside and 1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-β-D-glucopyranoside] was confirmed. For the first time, the compounds 1,7-bis-(3,4-dihydroxyphenyl)-3-hydroxyheptane-5-O-β-D-xylopyranoside and 1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-one-5-O-β-D-glucopyranoside were detected in grey alder bark. The results of experiments in vitro and in vivo have shown the high potential for diarylheptanoids-containing extracts in prophylaxis and/or treatment of diseases due to the metabolic disorders and ageing. The biological activity of grey alder extract was confirmed in in vitro experiments by incubation of human blood samples. In vivo experiments with rats also showed positive results. The conclusion is that grey alder extracts have a high potential for prevention of ageing related pathologies. Besides diarylheptanoids, the bark contains condensed tannins in commercially available quantity (12.5%). Eco-friendly wood adhesives were obtained on a tannins basis. The bark left after polyphenols isolation can be used in soil melioration and as a sorbent for the removal of oil products from water surface. The investigation of the phenolic pool of grey alder could contribute to cluster technologies within the biorefinery-based bark processing.

Mechanical potential of eco-OSB produced from durable and nondurable species and natural resins

Abstract Oriented strand board (OSB) panels were manufactured with different mixtures of pine and cypress heartwood and resins based on lignin or tannin to develop an eco-friendly wood composite with a natural durability against termite and fungi. Some physical properties and the major elastic moduli of bulk wood as well as of the manufactured panels were determined using different measurement techniques. In addition, a micromechanical model was adapted and validated with the experimental results. The good agreement obtained between the experimental data and model predictions indicates the proper assessment of the most influential parameters, such as raw material and adhesive properties, strand orientation, layer assembly and density profile. A parameter study, enlightening the effect of strand orientation on several elastic constants, enlarges the scope of experiments. We conclude with an optimal combination of resin and wood species mixture resulting in the best performance from a biological and mechanical standpoint.

Biological properties of an OSB eco-product manufactured from a mixture of durable and non durable species and natural resins

OSB panels were manufactured with a mixture of pine and cypress heartwood and lignin and tannin based resins in order to propose an eco-friendly wood composite. The resistance of OSB panels against Reticulitermes santonensis was tested according to EN 118 and EN 117 as well as in a field test. OSB made from cypress showed more resistance against the tested termite, the resistance decreased as the percentage of pine increased. The degree of attack differed according to the choice of standard procedure. The field test results revealed that in outdoor conditions and when the termites had a feeding choice, all mixtures showed the same behaviour. The decay resistance was assessed according to EN 12038, and the results revealed that the resistance increases when the percentage of cypress increases.