The increased use of wood composites in building materials results in a need for a better understanding of wood adhesion. The effects of water and temperature exposure on the durability of wood products were assessed using the double-cantilever beam (DCB) method of fracture testing. The relative durability of phenol-formaldehyde (PF) and isocyanate (pMDI) adhesives was compared using a 2-hour boil test and an environmental test. The feasibility of using oriented strandboard (OSB), oriented strand lumber (OSL) and parallel strand lumber (PSL) for the DCB fracture method was assessed. The fracture resistance of PF was reduced significantly by the aging exposures. The fracture resistance of pMDI did not decrease after the 2-hour boil test. The DCB fracture method was shown to be useful with a square-grooved machined specimen using OSB and OSL. / Master of Science

Lignocellulosic ethanol production currently uses expensive and harsh methods to extract wood sugars from small-diameter hardwood trees that otherwise would have little or no marketability. A byproduct that adds no value to the conversion process results, thus alternative methods are needed to make this fuel source cost-effective. This dissertation proposes only partially hydrolyzing southern hardwoods, extracting some polysaccharides for ethanol fermentation while leaving behind a modified wood material which could be used as furnish for manufacturing strand-based wood composites. Three treating solutions, 1% sulfuric acid, water, and 1% sodium hydroxide, along with untreated controls, were utilized in a partial hydrolysis at 150°C for 30 minutes. The treatments’ effects were measured by testing the mechanical, physical, surface, and durability properties of red oak, sweetgum, and yellow-poplar miniature beams (3 mm x 15 mm x 150 mm, t x r x l). These properties were then correlated to the polysaccharide content of the modified woods following treatment. All treatments provided a significant mass loss, with sweetgum’s mass loss being significantly greater than the other species. The initial effect of the partial hydrolysis on modulus of elasticity (MOE) showed water reduced MOE the least for each species. Sweetgum produced a higher reduction in MOE in all three solutions. Specific modulus was calculated to eliminate the density effect between the treatment combinations for measuring bending properties at oven-dry conditions. Sweetgum produced a lower SM in all treatments, and only the water treatment consistently reduced SM across all species. Wettablility was measured by dynamic contact angle analysis via the Wilhelmy plate technique in four probe liquids. Surface energies were then calculated by the geometric mean procedure. Acid and water treatments improved the wettability for all species. Alkaline treatment effects were species-specific. All treatments improved the surface energy of red oak. The AWPA E1-09 no-choice termite test determined mass loss due to Reticulitermes flavipes Kollar. Yellow-poplar averaged a significantly higher mass loss while wood treated in water or NaOH showed a higher degree of termite degradation compared to the controls. Polysaccharide content significantly correlated with mass loss due to treatment and specific modulus.

This research investigated the mechanical properties of laboratory manufactured, fire retardant treated (FRT) flakeboard in an effort to help establish proper manufacturing procedure and testing protocol for these types of composite products. Two sets of fire retardant treated and untreated panels were manufactured and tested to gauge the initial effects of treatment, as well as the effects of high temperature exposure on both panel types. Testing was also conducted on different bending specimen widths in an attempt to find the specimen size most suitable for testing flakeboard composites. Results indicated that FR treatment had an adverse effect on panel mechanical properties from both an initial standpoint as well as after the panels had been exposed. Results from the specimen width investigations revealed that using a wider dimension specimen for ASTM bending tests would reduce the amount of variation and error that can be found when testing smaller size samples.

The controlled degradation of wood surfaces with infrared light from a CO2 pulsed laser facilitated adhesion without the use of additional resins. Laser modification creates a surface phenomenon that physically and chemically alters the natural biopolymer organization of lignocellulosic materials in a way that promotes adhesion when hot pressed using typical industrial equipment. Laser optimization was determined through mechanical and microscopic observation. It was determined that a mild level of laser surface modification (scale of 30 W/mm2) resulted in the highest bond-line strength. The large spot size of the laser beam resulted in evenly modified surfaces. Surface analysis revealed that laser modification changed native wood morphology, hydrolyzed and vaporized hemicellulose, and enriched the surface with cellulose II and lignin. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FTIR) was used to analyze the bulk of the laser material. This experiment revealed a change in the hydroxyl region related to hydrogen bonding conformations between wood polymers, mainly cellulose. X-ray photoelectron spectroscopy (XPS) provided an elemental composition of the top 5 nanometers of the surface, which resulted in increased carbon-carbon/carbon-hydrogen linkages and decreased oxygen containing bonds due to laser ablation. Static acid-base contact angle analysis was conducted using three probe liquids to find the Lewis acid, Lewis base, and dispersion components of the top nanometer of surface chemistry. Contact angle analysis revealed laser modified samples had a surface free energy that remained similar to the control wood sample. In addition, the dispersion component of the surface free energy increased due to laser ablation while acid-base components were reduced. Atomic force microscopy (AFM) visually displays a reduction in surface roughness due to the laser technique. An additional set of experiments like thermal gravimetric analysis, thermal pre and post treatments, and heated ATR FTIR and XPS support findings which require more investigation into this adhesion phenomenon. / Master of Science

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Polymer composites, and in particular wood-polymer composites have become commercially and environmentally important materials. Studies in polyolefin-wood composites have mostly focused on polypropylene (PP) and polyethylene (PE). To our knowledge, no study has been undertaken on advancing impact polypropylene copolymer (IPPC)-wood composites as a suitable alternative to using PP and PE. IPPC have proven to be a suitable alternative to PP at low temperatures to improve impact resistance for manufactured polymer products, and could be a great addition to improved properties for wood polymer composites. This study shows that the physical properties of IPPC-wood composites can be markedly improved when compatibilizer(s) are used to improve the distribution of the wood within the matrix, as well as improving the interaction between the wood and the polymer matrix.. The use of different compatibilizers, vi polypropylene-graft-maleic anhydride (PPgMA) and poly(ethylene-co-vinyl alcohol) (EvOH) results in different physical properties. Using simple admixtures of the PPgMA and EvOH in IPPC-wood composites result in a large spread of results, while pre-reacting the PPgMA and EvOH to form a joint compatibilizer gives reproducible results w.r.t the physical testing. A study of the fundamental interactions of the compatibilizer(s) with the molecular components of the IPPCs was undertaken. The IPPCs used were fractionated by preparative temperature rising elution fractionation, and the fractions were mixed with the compatibilizers. To this end, fluorescence microscopy was utilized to study the interaction. The results clearly indicate that the interaction of the PPgMA with the fractions differ from that of the EvOH. These differences can be explained in terms of the chemical composition distribution within the IPPC fractions. Atomic force microscopy (AFM) was used to study adhesive forces between compatibilizer, polymer and cellulose and lignin. Successful coating of AFM tips with PPgMA and EvOH was achieved. Whilst interactions based on chemical force microscopy (CFM) could not be quantified, the AFM results in conjunction with fluorescence spectroscopy provided meaningful insight in the way that compatibilizers interact with both the wood and the impact copolymers used in this study. / AFRIKAANSE OPSOMMING: Polimeer saamgestelde material, en meer spesifiek hout-polimeer saamgestelde material het die afgelope tyd belangrike produkte geword, beide kommersieel en in verband met omgewingvriendelikheid. Navorsing op die gebied van poli(olefien)-hout komposiete het tot op hede meestal gefokus op die grbruik van poli(propileen) (PP) en poli(etileen) (PE). Sover dit on kennis strek is daar nog geen studie gedoen om die gebied van impak polipropileen kopolimere (IPPK)-hout komposiete uit te bou nie. IPPKs is ‘n geskikte alternatief vir PP in veral laetemperatuur aanwendings. Die gebruik van IPPKs as matriks vir die hout komposiete kan ‘n groot staqp vorentoe beteken. Hierdie studie wys dat die fisiese eienskappe van iPPK-hout komposiete merkwaardig verbeter kan word waneer versoeningmateriale gebruik word om die verspreiding van die hout in die polimeermatriks sowel as die interaksie tussen die hout en polimeer te verbeter. Die gebruik van verskillende versoenings material, t.w poli(propileen-ent-maleinsuur anhidried) (PPeMA) en pol(etlieen-ko-viniel alkohol) (EVOH). Deur gebruik te maak van eenvoudige mengsels van PPeMA en EVOH in IPPK-hout composite het ‘n geweldige wye verpreiding van resultate tot gevolg gehad, terwyl ‘n voorafgaande reaksie tussen die PPeMA en die EVOH om ‘n saamgestelde versoeningmateriaal te maak tot gevolg gehad het dat reproduseerbare resultate verkry kon word. ‘n Studie van die fundamentele interaksies van die versoeningsmateriale met die molkulêre komponente van die IPPKs is uitgevoer. Die IPPKs is gefraksioneer deur preparatiewe temperatuur-stygende uitloog frakasionering en die fraksies is gemeng met die versoeningmateriale. Fluoressensie mikroskopie is gebruik om hierdie interaksies te bestudeer. Die resultate dui duidelik daarop dat die interaksie van die PPeMA met die fraksies verskil met die van die EVOH. Die verskille kan verduidelik word aan die hand van die chemiese samestelling verspreiding van die IPPK fraksies. Atoomkrag mikroskopie (AKM) is gebruik om die adhesive-kragte tussen die versoeningmateriale, polimere, sellulose en lignien. AKM tippe is suksesvol bedek met PPeMA en EVOH, onderskeidelik. Alhoewel interaksies gebaseer op chemiese krag mikroskopie (CKM) nie gekwantifiseer kon word nie, lewer hierdie resultate tesame met die fluoressensie spektroskopie unieke insig in die manier wat versoeningmateriale met beide die hout en die polimeer reageer.

O uso de recursos florestais e madeireiros como cargas em matrizes poliméricas pode originar novos materiais com forte apelo ecológico e econômico. Dentre os resíduos do processamento mecânico e químico da madeira, há uma série de materiais de fácil acesso que podem ser manipulados a partir de certas técnicas de biorrefinaria, tais como a madeira, a casca de madeira, as pinhas (frutos do pinus), as acículas (folhas do pinus), a lignina residual (processo kraft) e o lodo de papel derivadas do processo químico de polpação celulósica. Tais matérias primas foram incorporadas em espumas rígidas e semi-rígidas de poliuretano (PU) processadas pelo método da expansão livre, utilizando-se uma mistura de óleo de mamona e glicerina loira como biopoliol, com vistas a obtenção de espumas quimicamente estáveis e ecologicamente corretas. A compatibilidade de algumas dessas cargas no sistema PU foi testada mediante reações induzidas na presença de isocianato e catalisador. As espumas PU foram caracterizadas por meio de técnicas de microscopia e espectroscopia, além de ensaios mecânicos, térmicos, higroscópicos, óticos, de resistência a chamas e de resistência à radiação UV. Por fim, foi avaliado o efeito de expansões sob confinamento nas propriedades morfológicas, mecânicas e térmicas do PU puro e de uma espuma carregada PU/madeira As espumas apresentaram estabilidade química e a inserção das cargas no PU puro possibilitou a obtenção de espumas com células homogêneas, melhor desempenho higroscópico, níveis similares de condutividade térmica e flamabilidade, além de maior brilho e diferentes padrões de cor. A farinha de madeira apresentou a maior afinidade com o sistema PU, seguida pela lignina kraft, resultando em espumas carregadas com células menores, mais arredondadas e com maior teor de células fechadas, além de espumas com maiores estabilidades térmica e dimensional. Todas as espumas apresentaram fotodegradações similares, marcadas por uma cor alaranjada, acompanhada por uma acentuada perda de brilho. As espumas carregadas naturalmente mais escuras foram mais resistentes à fotodegradação por serem capazes de causar um efeito contrário ao da descoloração natural do PU quando sujeito aos raios UV. O confinamento diminuiu o diâmetro médio de células da espuma PU/madeira e a anisotropia do PU puro, levando a formação de células mais homogêneas, marcadas por números de arestas rompidas e de células abertas aparentemente menores, que resultaram em maiores densidades aparentes e melhores propriedades mecânicas para espumas preparadas a 50% de confinamento e menor condutividade térmica para as espumas confinadas a 70%. / The use of forestry and wood-based resources as fillers in polymer matrices may originate new materials with strong environmental and economic appeals. Among the wastes from chemical and mechanical processing of wood, there are many materials readily available, which can be handled through biorrefinary techniques, like wood flour, wood bark, pine cones (fruits), pine needles (leaves), residual lignin (e.g. from kraft process) and paper sludge, the last two from the chemical processing of cellulosic pulp. In this thesis, such raw materials were incorporated into rigid and semi-rigid polyurethane (PU) foams prepared by the free-rising pouring method, using a mixture of castor oil and crude glycerin as a bio-based polyol in order to achieve chemically stable and eco-friendly foams. Compatibility of the fillers with the PU system was evaluated using induced reactions in the presence of isocyanate and catalyst. The PU foams were characterized by microscopy and spectroscopy techniques, as well as mechanical, thermal, hygroscopic, optical, flame resistance and UV radiation resistance tests. And the effect of rising under confinement on the morphological, mechanical and thermal properties of neat PU and wood/PU foam composites was also investigated The foams presented chemical stability and the addition of fillers into PU yielded foams with more homogeneous cells, better hygroscopic performance, similar thermal conductivities and flammabilities, as well as higher specular glosses and different colorimetric patterns. The wood flour presented the highest affinity with the PU system, followed by kraft lignin, resulting in foam composites with smaller and more rounded cells, with higher closed-cells content, and increased thermal and dimensional stabilities. All foams presented similar photodegradation behavior characterized by an orange color and a significant loss in specular gloss. The foam composites, being naturally darker, were more resistant to photodegradation, since they had an opposite effect related to natural discoloration under UV radiation. The confinement decreased cell diameter for the wood filled PU foam and the anisotropy index for neat PU foam, yielding more homogeneous cells, with fewer broken edges and open-cells, with greater apparent densities and better mechanical properties for foams prepared at 50% confinement and lower thermal conductivity for foams confined at 70%.

Wood composites are widely used in construction applications because of their superior dimensional and structural attributes over raw wood products. However, current wood composite manufacturing practices, which rely on thermal-curing of adhesives, are expensive, energy intensive, time consuming and are prone to manufacturing defects. Use of radiation curable adhesives (RCAs) could potentially answer all of these issues. Specifically, use of electron-beam (e-beam) radiation has been increasing in areas of research and industry where rapid, low-temperature polymerization is required and low energy consumption is desired. For e-beams to be used in wood composites, however, it must be determined whether or not the wood is structurally impacted by irradiation, and to what extent. Maple beams irradiated with a range of e-beam dosages were studied in three-point bend tests to assess the changes in bulk properties of the wood, and were further studied with infrared spectroscopy to identify chemical changes resulting from the radiation treatments. Also, dynamic mechanical analysis (DMA) was performed on maple veneers treated with the same doses of radiation to characterize changes in the viscoelastic properties. Furthermore, while RCAs and their curing have been studied, it is important to understand if the presence of wood will impede the polymerization of these adhesives, and to what extent. Maple veneers impregnated with one of two resins were cured with the same e-beam dosages and investigated by means of DMA and FTIR spectroscopy. Swelling tests were conducted to detect interaction between the resins and the wood, which would indicate good interfacial bonding in the composite matrix. Notable loss of strength was observed in the irradiated wood, especially at 180kGy. Monitoring the glass transition temperature (Tg) and activation energy (Ea) derived from DMA revealed that the most destructive trends in the wood began around 80kGy. Cure of resins in the composites was hindered by the presence of the wood, but both resins did eventually reach complete cure at doses higher than what the neat resins required. Interaction between the resins and the wood was evident. In the end, results indicate that there is a range of radiation dosages in which the resin in a wood composite can be cured without destroying the structural integrity of the wood.

O uso de recursos florestais e madeireiros como cargas em matrizes poliméricas pode originar novos materiais com forte apelo ecológico e econômico. Dentre os resíduos do processamento mecânico e químico da madeira, há uma série de materiais de fácil acesso que podem ser manipulados a partir de certas técnicas de biorrefinaria, tais como a madeira, a casca de madeira, as pinhas (frutos do pinus), as acículas (folhas do pinus), a lignina residual (processo kraft) e o lodo de papel derivadas do processo químico de polpação celulósica. Tais matérias primas foram incorporadas em espumas rígidas e semi-rígidas de poliuretano (PU) processadas pelo método da expansão livre, utilizando-se uma mistura de óleo de mamona e glicerina loira como biopoliol, com vistas a obtenção de espumas quimicamente estáveis e ecologicamente corretas. A compatibilidade de algumas dessas cargas no sistema PU foi testada mediante reações induzidas na presença de isocianato e catalisador. As espumas PU foram caracterizadas por meio de técnicas de microscopia e espectroscopia, além de ensaios mecânicos, térmicos, higroscópicos, óticos, de resistência a chamas e de resistência à radiação UV. Por fim, foi avaliado o efeito de expansões sob confinamento nas propriedades morfológicas, mecânicas e térmicas do PU puro e de uma espuma carregada PU/madeira As espumas apresentaram estabilidade química e a inserção das cargas no PU puro possibilitou a obtenção de espumas com células homogêneas, melhor desempenho higroscópico, níveis similares de condutividade térmica e flamabilidade, além de maior brilho e diferentes padrões de cor. A farinha de madeira apresentou a maior afinidade com o sistema PU, seguida pela lignina kraft, resultando em espumas carregadas com células menores, mais arredondadas e com maior teor de células fechadas, além de espumas com maiores estabilidades térmica e dimensional. Todas as espumas apresentaram fotodegradações similares, marcadas por uma cor alaranjada, acompanhada por uma acentuada perda de brilho. As espumas carregadas naturalmente mais escuras foram mais resistentes à fotodegradação por serem capazes de causar um efeito contrário ao da descoloração natural do PU quando sujeito aos raios UV. O confinamento diminuiu o diâmetro médio de células da espuma PU/madeira e a anisotropia do PU puro, levando a formação de células mais homogêneas, marcadas por números de arestas rompidas e de células abertas aparentemente menores, que resultaram em maiores densidades aparentes e melhores propriedades mecânicas para espumas preparadas a 50% de confinamento e menor condutividade térmica para as espumas confinadas a 70%. / The use of forestry and wood-based resources as fillers in polymer matrices may originate new materials with strong environmental and economic appeals. Among the wastes from chemical and mechanical processing of wood, there are many materials readily available, which can be handled through biorrefinary techniques, like wood flour, wood bark, pine cones (fruits), pine needles (leaves), residual lignin (e.g. from kraft process) and paper sludge, the last two from the chemical processing of cellulosic pulp. In this thesis, such raw materials were incorporated into rigid and semi-rigid polyurethane (PU) foams prepared by the free-rising pouring method, using a mixture of castor oil and crude glycerin as a bio-based polyol in order to achieve chemically stable and eco-friendly foams. Compatibility of the fillers with the PU system was evaluated using induced reactions in the presence of isocyanate and catalyst. The PU foams were characterized by microscopy and spectroscopy techniques, as well as mechanical, thermal, hygroscopic, optical, flame resistance and UV radiation resistance tests. And the effect of rising under confinement on the morphological, mechanical and thermal properties of neat PU and wood/PU foam composites was also investigated The foams presented chemical stability and the addition of fillers into PU yielded foams with more homogeneous cells, better hygroscopic performance, similar thermal conductivities and flammabilities, as well as higher specular glosses and different colorimetric patterns. The wood flour presented the highest affinity with the PU system, followed by kraft lignin, resulting in foam composites with smaller and more rounded cells, with higher closed-cells content, and increased thermal and dimensional stabilities. All foams presented similar photodegradation behavior characterized by an orange color and a significant loss in specular gloss. The foam composites, being naturally darker, were more resistant to photodegradation, since they had an opposite effect related to natural discoloration under UV radiation. The confinement decreased cell diameter for the wood filled PU foam and the anisotropy index for neat PU foam, yielding more homogeneous cells, with fewer broken edges and open-cells, with greater apparent densities and better mechanical properties for foams prepared at 50% confinement and lower thermal conductivity for foams confined at 70%.

O uso de recursos florestais e madeireiros como cargas em matrizes poliméricas pode originar novos materiais com forte apelo ecológico e econômico. Dentre os resíduos do processamento mecânico e químico da madeira, há uma série de materiais de fácil acesso que podem ser manipulados a partir de certas técnicas de biorrefinaria, tais como a madeira, a casca de madeira, as pinhas (frutos do pinus), as acículas (folhas do pinus), a lignina residual (processo kraft) e o lodo de papel derivadas do processo químico de polpação celulósica. Tais matérias primas foram incorporadas em espumas rígidas e semi-rígidas de poliuretano (PU) processadas pelo método da expansão livre, utilizando-se uma mistura de óleo de mamona e glicerina loira como biopoliol, com vistas a obtenção de espumas quimicamente estáveis e ecologicamente corretas. A compatibilidade de algumas dessas cargas no sistema PU foi testada mediante reações induzidas na presença de isocianato e catalisador. As espumas PU foram caracterizadas por meio de técnicas de microscopia e espectroscopia, além de ensaios mecânicos, térmicos, higroscópicos, óticos, de resistência a chamas e de resistência à radiação UV. Por fim, foi avaliado o efeito de expansões sob confinamento nas propriedades morfológicas, mecânicas e térmicas do PU puro e de uma espuma carregada PU/madeira As espumas apresentaram estabilidade química e a inserção das cargas no PU puro possibilitou a obtenção de espumas com células homogêneas, melhor desempenho higroscópico, níveis similares de condutividade térmica e flamabilidade, além de maior brilho e diferentes padrões de cor. A farinha de madeira apresentou a maior afinidade com o sistema PU, seguida pela lignina kraft, resultando em espumas carregadas com células menores, mais arredondadas e com maior teor de células fechadas, além de espumas com maiores estabilidades térmica e dimensional. Todas as espumas apresentaram fotodegradações similares, marcadas por uma cor alaranjada, acompanhada por uma acentuada perda de brilho. As espumas carregadas naturalmente mais escuras foram mais resistentes à fotodegradação por serem capazes de causar um efeito contrário ao da descoloração natural do PU quando sujeito aos raios UV. O confinamento diminuiu o diâmetro médio de células da espuma PU/madeira e a anisotropia do PU puro, levando a formação de células mais homogêneas, marcadas por números de arestas rompidas e de células abertas aparentemente menores, que resultaram em maiores densidades aparentes e melhores propriedades mecânicas para espumas preparadas a 50% de confinamento e menor condutividade térmica para as espumas confinadas a 70%. / The use of forestry and wood-based resources as fillers in polymer matrices may originate new materials with strong environmental and economic appeals. Among the wastes from chemical and mechanical processing of wood, there are many materials readily available, which can be handled through biorrefinary techniques, like wood flour, wood bark, pine cones (fruits), pine needles (leaves), residual lignin (e.g. from kraft process) and paper sludge, the last two from the chemical processing of cellulosic pulp. In this thesis, such raw materials were incorporated into rigid and semi-rigid polyurethane (PU) foams prepared by the free-rising pouring method, using a mixture of castor oil and crude glycerin as a bio-based polyol in order to achieve chemically stable and eco-friendly foams. Compatibility of the fillers with the PU system was evaluated using induced reactions in the presence of isocyanate and catalyst. The PU foams were characterized by microscopy and spectroscopy techniques, as well as mechanical, thermal, hygroscopic, optical, flame resistance and UV radiation resistance tests. And the effect of rising under confinement on the morphological, mechanical and thermal properties of neat PU and wood/PU foam composites was also investigated The foams presented chemical stability and the addition of fillers into PU yielded foams with more homogeneous cells, better hygroscopic performance, similar thermal conductivities and flammabilities, as well as higher specular glosses and different colorimetric patterns. The wood flour presented the highest affinity with the PU system, followed by kraft lignin, resulting in foam composites with smaller and more rounded cells, with higher closed-cells content, and increased thermal and dimensional stabilities. All foams presented similar photodegradation behavior characterized by an orange color and a significant loss in specular gloss. The foam composites, being naturally darker, were more resistant to photodegradation, since they had an opposite effect related to natural discoloration under UV radiation. The confinement decreased cell diameter for the wood filled PU foam and the anisotropy index for neat PU foam, yielding more homogeneous cells, with fewer broken edges and open-cells, with greater apparent densities and better mechanical properties for foams prepared at 50% confinement and lower thermal conductivity for foams confined at 70%.

This study examined the feasibility of using (BETA)-cyclodextrins ((BETA)CDs), which are derived from starch, as agents to stabilize volatile and leachable biocides for the protection of wood and wood composites. The encapsulation of volatile natural antimicrobial compounds, such as allyl isothiocyanate (AITC) and essential oils (EOs), in βCDs was qualitatively confirmed by Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) method and the maximum inclusion yield was quantitatively estimated by ultraviolet-visible spectrophotometry (UV/VIS) while the partial fixation of leachable borates with βCD was confirmed by ATR-FTIR and nuclear magnetic resonance (NMR) techniques. The efficacy of the βCD complexes as wood preservatives of southern yellow pine and randomly Oriented Strand Board (OSB) was examined in soil block tests (AWPA E10-16 and E22-16 standard). The results indicate that (A) (BETA)CDs suppress the premature leaching of otherwise volatile natural compounds and suggest a novel approach to the application of volatile or water-immiscible natural preservatives for wood and wood composites protection; (B) (BETA)CD can be used as an agent for partial fixation of boric acid to form boric acid esters. However, the borate esters are susceptible to leach out after AWPA E11 test and not suitable for protection against Gloeophyllum trabeum and Postia placenta in outdoor conditions.