Graduation date: 1994

Professional builders (PRO's) and do-it-yourself (DIY) households throughout the U.S. were surveyed individually to assess their overall knowledge/awareness, product and service attribute preference and the general product quality and risk perceptions of CCA pressure treated lumber products. Primary data were acquired via two separate nationwide mail surveys; one included 3,361 PRO's, the other was administered to 3,224 households. Findings indicate that each of these retail customer groups is comprised of distinct subsegments that may be distinguished in various ways. These meaningful PRO segmentation strategies emerged from analysis of 543 PRO respondents portraying treated lumber customers according to the following: (1) geographic region as characterized by product and service attribute preferences, opinions, knowledge and demographics, (2) quality perceptions in terms of the relationship between benefits sought and product quality perception opinions and (3) physical risk or safety perceptions based on a risk personality type as delineated further according to three sets of psychographic predictor variable sets. The 491 responding DIY'ers were segmented according to risk perception orientation similarly to the builders. In addition, the DIY'er was profiled with regional breakdowns for treated lumber usage, applications and purchase intent, the husband/wife involvement in treated lumber buying decisions, knowledge, and product and service attribute importance. Consumer knowledge and awareness of pressure treated lumber products, in general, is very low. Only one-third of PRO's and 21% of DIY'ers could recall, unaided, at least one brand of treated lumber. Moreover, approximately one-third of all PRO and DIY respondents are knowledgeable about the preservative chemicals and a mere 38% of the 436 PRO respondents and 23% of the DIY respondents who have used treated lumber products from 1985-1987 could successfully identify the correct response from a multiple choice question which described the contents of Consumer Information Sheets (CIS's). Primarily through reading materials, Permanent Wood Foundations (PWF's) are well known among builders with 70% aware. However, only one-fourth of DIY'ers have ever heard of PWF systems. / Ph. D.

Boron treated test houses at Mississippi State University’s Dorman Lake test site in Starkville, MS were built in 1989 to investigate the effectiveness of boron treatments with exposure to natural weathering. After being undisturbed for more than 20 years, samples were taken to evaluate the remaining levels of original treatments in the test houses. Visual evaluation of the test structures, curcumin test, and ICP-MS analysis of the borate content shows borates are a capable and effective long-term treatment for wood used in construction. No appreciable damage due to termite feeding was observed. Boron was still detectable by curcumin staining and positive boron levels were confirmed by ICP-MS analysis.

Wood disks in various states of decay can be inexpensively preserved and prepared for accurate crossdating and precise tree-ring measurement by impregnation with commercial wood glue. The technique does not affect the dimensions or physiological features of samples preserved in this manner. Dead red spruce trees on Mt. Washington, New Hampshire, remain available for dendrochronological examination as long as 29 years after their last year of stem growth.

Les travaux de recherche présentés portent sur l'utilisation des produits de la liquéfaction des écorces d'épicéa dans le phénol pour la préservation du bois. Les produits de la liquéfaction permettent la synthèse d'une résine thermodurcissable de type phénolique. Les résines formulées sont imprégnées dans le bois suivi d'un durcissement in situ. Un prétraitement est mis au point dans le but d'enrichir la fraction phénolique des écorces. Ce prétraitement consiste à hydrolyser les polysaccharides principalement la cellulose et les hémicelluloses dans une solution acide. Ce prétraitement permet d'obtenir un taux de lignine dans les écorces de 60 %, et un taux de cellulose de 28 %. Un procédé de liquéfaction dans un système composé de phénol, d'eau et d'éthanol est optimisé dans le but d'obtenir des taux de liquéfaction supérieur à 85 %, et un taux d'écorces liquéfiées par rapport à la masse de phénol supérieur à 50 %. Les produits de la liquéfaction présentent l'avantage de polymériser sans ajout de formaldéhyde. La durabilité conférée au bois par les résines est bonne, surtout pour les résines phénol/formaldéhyde. Les résines sont peu lessivables. L'imprégnation du bois par les résines provoque un gonflement du bois ce qui améliore la stabilité dimensionnelle de ce dernier / This work focuses on the use of liquefaction products of spruce bark in phenol for the wood preservation. The liquefaction products allow the synthesis of phenolic thermosetting resins. The formulated resins were impregnated into the wood followed by in situ polymerization. A pretreatment was developed in order to increase the phenolic compounds in the spruce bark. This step is an acid hydrolysis of polysaccharides. This pretreatment allowed obtaining a Klason lignin content of 60 %, and a cellulose content of 28 %. A liquefaction process was developed in a mixture of solvent composed of phenol, ethanol, and water. The optimized experimental conditions allowed obtaining a liquefaction yield superior to 85 %, with liqui?ed bark/phenol ratio superior to 50 %. The lique?ed products had the advantage to polymerize without formaldehyde. The resins enhanced the wood durability especially for the phenol/formaldehyde resins. The leaching was low. The wood impregnation allowed a wood swelling, thereby the impregnated wood had a better dimensional stability

A madeira quando usada em contato direto com o solo, é atacada por agentes biológicos, principalmente fungos apodrecedores e cupins subterrâneos. Uma maneira de ampliar as possibilidades de utilização das espécies de baixa durabilidade natural, como as do gênero Pinus, é através do tratamento químico preservante. No entanto, faltam informações disponíveis que indiquem a durabilidade destas madeiras em serviço. A fim de se determinar a durabilidade da madeira do gênero Pinus tratada com preservantes, a Escola Superior de Agricultura "Luiz de Queiroz" e o Instituto Florestal do Estado de São Paulo instalaram, em 1980, campos de apodrecimento segundo método de ensaio sugerido pelo IUFRO (International Union of Forestry Research Organizations). As espécies utilizadas no ensaio foram o Pinus elliottii Engl. var. elliottii, o Pinus caribaea Mor. var. hondurensis, B & G., o Pinus oocarpa Shied e o Pinus kesiya Royle ex Gordon; tratadas com os preservantes CCA tipos A, B e C, CCB e pentaclorofenol, em cinco níveis de retenção. Em continuidade ao projeto, foi inspecionado o campo instalado na Estação Experimental de Mogi-Guaçu, visando avaliar o estado de sanidade do material. A análise dos resultados obtidos até o momento, 21 anos de exposição demonstrou que não houve diferença no comportamento entre espécies. Os índices de comportamento mais altos (maior expectativa de durabilidade) correspondem aos tratamentos com CCA tipos A, B e C em retenções acima de 7,5 kg/m3. Mesmo para os tratamentos que apresentaram os menores índices de comportamento (CCA tipo C com retenções de 5,0 kg/m 3 e CCB com 5,9 kg/m 3 ), é prevista uma durabilidade de 30 anos em serviço. / When used in ground contact, wood is deteriorated by biological agents, as root fungi and subterranean termites. A way to increase the use of wood species of low natural durability, as the Pinus lumber, is the preservative treatment. However, there is a lack of information indicating the durability of treated wood. In order to determine the durability of preservative treated Pinus lumber, the Escola Superior de Agricultura "Luiz de Queiroz" and the Instituto Florestal do Estado de São Paulo installed, in 1980, fields tests according to the IUFRO (International Union of Forestry Research Organizations). The species under test were Pinus elliottii Engl. var. elliottii, Pinus caribaea Mor. var. hondurensis, B & G., Pinus oocarpa Shied and Pinus kesiya Royle ex Gordon; treated with the preservatives CCA types A, B and C, CCB and pentachlorophenol, in five retention levels. In continuity to the project, the material installed in the test site of Experimental Station of Mogi-Guaçu was inspected, to evaluate the degree of attack. The analysis of results obtained till now, after 21 years of exposure, demonstrated that there are no differences in durability related with species. The highest performance index (longer durability expectation) correspond to treatments with CCA types A, B and C in retentions above 7,5 kg/m3. Even for the treatments that presented lowest performance index (CCA type C with retention of 5,0 kg/m 3 and CCB with 5,9 kg/m 3 ), the durability expectation is 30 years in service.

A região objeto do presente estudo compreende uma área localizada às margens do rio Taquari, no município de Triunfo (RS), que pertence à bacia hidrográfica Taquari – Antas, com contaminação de solo específica por preservantes de madeira, cujo passivo ambiental são pentaclorofenol, creosoto e hidrosal arseniato de cobre cromado. O local é percorrido por corpos d’água associados à drenagem principal, formando sub-bacias. Através dos ensaios de microssuspensão com Salmonella/microssoma e Allium cepa, o trabalho teve por objetivo relacionar a atividade genotóxica com rotas de dispersão de poluentes. Analisando a área do sítio contaminado a partir dos extratos orgânicos do material drenado para o corpo d’água, após eventos de chuvas significantes e análises de extrato orgânico, água intersticial e sedimento bruto do rio. No teste Salmonella/microssoma, diversas linhagens permitiram avaliar diferentes danos ao DNA, como deslocamento no quadro de leitura (TA97a e TA98) e substituição de pares de base (TA100) em ausência (-S9) e presença (+S9) de ativação metabólica. No teste de Allium, foi possível verificar alterações em nível cromossômico. Respostas positivas de mutagenicidade pelo teste de Salmonella/microssoma do material exportado para fora da área do sítio indicam que este material pode estar sendo carreado para o rio Taquari. Isto pode ser evidenciado pela atividade mutagênica detectada em ambos os testes, na amostra de sedimento do rio coletada em frente ao sítio contaminado. O ponto a jusante no rio em relação ao ponto em frente ao sítio contaminado também foi avaliado e atividade mutagênica foi detectada, já o ponto de referência a montante mostrou pequena atividade mutagênica proveniente de fonte de contaminação diferente. Entretanto, tais poluentes não foram detectados no ponto abaixo. Os bioensaios empregados puderam indicar um possível risco de contaminação para o rio Taquari e mostraram ser eficientes para avaliar a mutagenicidade no material drenado do solo e no sedimento do rio. Embora a atividade mutagênica possa ser relacionada em parte à presença de hidrocarbonetos policíclicos aromáticos nos extratos orgânicos das amostras, derivados do preservante de madeira creosoto ou de fontes antrópicas diversas, outros compostos orgânicos podem ser encontrados nos extratos, uma vez que resíduos de pentaclorofenol estão presentes no sítio. Além disso, a complexidade das amostras de sedimento do rio poderia ainda sofrer a influência de traços de metais pesados. / Mutagenic activity, using Salmonella/microsome and Allium cepa bioassay, was employed as markers to detect pollutant dispersion routes in contaminated soil site covered by water bodies associated with the drainage toward the river. The site of the present study comprises an area located along the banks of the Taquari River, in the city Triunfo (RS) belonging to the Taquari - Antas river basin with identified environmental contaminants (pentachlorophenol, creosote and hydrosalt CCA). The Salmonella/microsoma test evaluated organic extracts of the material drained into the water body after significant rain events as well as Taquari River samples including organic sediment extract, interstitial water and gross sediment. In the Salmonella/microsome test, different strains enabled evaluation of different DNA mutations including frameshift (TA97a and TA98) and base pair substitution (TA100) in the absence (- S9) and presence (+S9) of metabolic activation. The Allium test allowed verification of chromosomal alterations. Positive mutagenicity results in the Salmonella/microsome assay of material from the area indicate that contaminant mixtures may have drained into the Taquari River, as indicated by mutagenic activity detected in both bioassays in sediment samples collected at the contaminated site. Mutagenic activity was also detected at a site downstream from the contaminated site. Although the reference area upstream showed low mutagenic activity originating from a different pollutant source, such pollutants were not found at the downstream sites. The bioassays employed, mainly the Salmonella/microsome assay, can indicate a possible contamination route toward the Taquari River and were proven efficient at evaluating the mutagenicity of drained soil material and sediment from the river.

A durabilidade da madeira preservada quando em contato direto com o solo, é determinada, principalmente, pela concentração do preservante na madeira, usualmente definida como retenção. Dentre os diversos produtos usados na preservação da madeira, a literatura especializada é concordante ao afirmar que o CCA (arsenato de cobre cromatado) é um dos mais eficientes, com citações de durabilidade acima de 40 anos. Contudo, também é citada a perda do produto ao longo do tempo, a qual poderia comprometer sua eficiência. Assim o presente trabalho teve como objetivo quantificar a retenção atual de CCA tipo A em estacas de Pinus, após 21 anos de exposição em campo de apodrecimento, buscando relacionar o nível de retenção com a possível perda de produto e com a durabilidade da madeira. O material para ensaio foi coletado de um campo de apodrecimento com estacas (Padrão IUFRO); quantificando-se a retenção atual através da técnica de espectrofotometria de absorção atômica e comparando-se os resultados com a retenção inicial. Foi possível comprovar a perda de CCA-A na madeira tratada, a qual está diretamente relacionada com o nível de retenção inicial. Dentre oscomponentes do preservante, as maiores perdas foram observadas para o Cu, e as menores para o Cr; levando ao desbalanceamento entre os componentes do produto (CCA-A) que permanece na madeira. Todavia, a redução observada na retenção do CCA-A, até o momento, não afetou a durabilidade da madeira preservada. / The durability of treated wood in direct ground contact is mainly determined, by the concentration of preservative in wood, usually defined as retention. Among the products used to preserve wood, specialized literature aggress about CCA (chromated copper arsenate) as one of the most efficients, with citations of durability above 40 years. However, product loss along exposure time is also noticed, which could compromise its efficiency. This research has as objective, to quantify the current retention of CCA type A in Pinus stakes, after 21 years of exposure in field test, trying to relate the level of retention to the possible product loss and to wood durability . The material on trial was collected from a stake field test (IUFRO Standard); in order to quantify the current retention through spectroscopy atomic absorption technique and to compare the results with the initial retention. It was possible to prove the CCA-A loss in the treated wood, which is directly related to the level of initial retention. From individual preservative components, copper (CuO), showed the biggest loss, while chromium (CrO3) showed the lesser one. As a result, the remanaing CCA-A in the lumber turned unbalanced. However, the reduction observed in the retention of the CCA-A, until this moment, did not affect the durability of preserved wood.

Western juniper and cinnamon essential oils were combined with ethanol at 2.5, 5, and 10% concentrations by weight and applied to hybrid poplar (Populus trichocarpa x P. deltoids) veneers by vacuum soaking to produce a naturally durable wood veneer with increased mechanical properties for use in structural composites. Half of these veneers were then modified using viscoelastic thermal compression to increase veneer density and modulus of elasticity. Following densification, unprocessed and VTC processed veneers receiving an essential oil treatment were subjected to an AWPA E21-06 Formosan termite exposure test, AWPA E24-06 mold box test, and brown rot (Gloeophyllum trabeum) decay bending test. While VTC processing drastically reduced the abundance of chemical components inherent within essential oil treatments, veneer specimens without VTC processing showed increased durability. A 10% juniper oil treatment drastically reduced Formosan termite attack on hybrid poplar veneers while a 10% cinnamon oil treatment significantly reduced mold growth. Timbor��, an industrial powdered borate treatment, withstood VTC processing and inhibited Formosan termite attack and mold growth. Tests to evaluate the effectiveness of essential oil treatments against brown rot were unsuccessful. Results suggest that incorporating a disodium octaborate tetrahydrate (DOT) treatment prior to VTC processing could help improve VTC wood durability. / Graduation date: 2013

Diese Arbeit besteht aus drei Teilen. Im ersten Teil wurde Holz mit verschiedenen, kommerziell erhältlichen Kieselsolen behandelt, die unterschiedliche pH-Werte und Oberflächenmodifikationen aufwiesen. Basische Kieselsole vermochten nicht in das Holz einzudringen, da ihr pH-Wert während des Eindringens absinkt und es zur Ausfällung des Kieselsols im Holz kommt. Neutrale und saure Kieselsole hingegen konnten problemlos in das Holz eingebracht werden. Eines der sauren Kieselsole, welches mittels Aluminumoxychlorid kationisch modifiziert war, reduzierte die Wasseraufnahme und den pilzlichen Abbau durch die Braunfäule Coniophora puteana (Kiefer) und die Weißfäule Trametes versicolor (Buche). Im Bläuetest zeigte sich ein verminderter Befall durch Aureobasidium pullulans, allerdings kein kompletter Schutz gegen diesen Pilz. Auch die kleinsten verfügbaren Partikelgrößen für Kieselsole ergaben keinerlei Zunahme des Zellwandvolumens (chemische Quellung, Bulking), was darauf hinweist, dass eine Eindringung in die Zellwand nicht stattfand. Es erscheint daher nicht möglich, Kieselsole in die Zellwand einzubringen und die Dimensionsstabilität des Holzes zu verbessern. Da Kieselsol lediglich in die Lumen der Holzzellen eingebracht werden kann, kann die Behandlung nicht als wirkliche Holzmodifizierung angesehen werden. Wegen der vielversprechenden Ergebnisse in den Wasseraufnahmeversuchen und den Pilztests wurde mit dem kationischen Kieselsol behandeltes Holz thermogravimetrisch und in einem Brandtest untersucht. Im thermogravimetrischen Test zeigte sich eine leicht verminderte Pyrolysetemperatur (eine übliche Wirkung von Feuerschutzmitteln), die Holzkohlemenge war jedoch nicht erhöht. Dies zeigt, dass die Menge an brennbaren Gasen, die während der Pyrolyse freiwerden, durch das Kieselsol nicht vermindert wurde. Auch zeigte die resultierende Holzkohle gleiche Oxidationseigenschaften wie die Holzkohle der Kontrollen. Im Brandtest wurden die Branddauer, die Brandgeschwindigkeit und der Gewichtsverlust vermindert. Das Nachglühen der Holzkohle wurde komplett unterbunden. Alle diese Effekte waren jedoch relativ klein verglichen mit den Effekten eines kommerziell erhältlichen Feuerschutzsalzes, welches ebenfalls als Referenzbehandlung getestet wurde. Im zweiten Teil der Arbeit wurden acetoxyfunktionelles Silan und verschiedene Polydimethylsiloxane (PDMS) mit Acetanhydrid kombiniert, um Holz zu acetylieren. Die PDMS hatten die folgenden Funktionalitäten: Amino, Acetoxy, Hydroxy und nicht-funktionell. Die beste Hydrophobierung des acetylierten Holzes wurde durch die Kombination mit acetoxyfunktionellem PDMS erreicht, welches anschließend in verschiedenen Konzentrationen getestet wurde. Eine Konzentration von 1% in Acetanhydrid zeigte bereits eine maximale Hydrophobierung, welches darauf schließen lässt, dass die inneren Oberflächen des Holzes mit dem PDMS belegt und hydrophobiert wurden. Die Pilzresistenz des behandelten Holzes wurde durch die Kombination mit dem PDMS nicht beeinflusst. Bei Wasserlagerung zeigte sich eine leichte Überquellung des Holzes, welches mit der Kombination von Acetanhydrid und PDMS acetyliert worden war. Untersuchungen der Biegefestigkeit und Bruchschlagarbeit ergaben jedoch keinen Einfluss. Im dritten Teil der Arbeit wurden wasserbasierte Emulsionen von funktionellen PDMS zur Imprägnierung von Holz eingesetzt. Es wurde untersucht, ob Resistenz gegen pilzlichen Abbau und Hydrophobierung wie auch erhöhte Dimensionsstabilität mit dieser Behandlung erreicht werden kann. Die α-ω-gebundenen Funktionalitäten der PDMS waren: Amino, Carboxy, Epoxy und Carbobetain. Die stärkste Hydrophobierung wurde mit dem carbobetain-funktionellen PDMS erreicht, allerdings ergab diese Behandlung keine verbesserte Pilzresistenz gegenüber einem Abbau durch Coniophora puteana und Trametes versicolor. In dieser Hinsicht die beste Wirkung zeigte die Behandlung mit carboxy-funktionellem PDMS. Dieses Material verminderte jedoch die Wasseraufnahmerate nur ungenügend und wurde außerdem stark ausgewaschen. Daher wurden in der Folge amino-funktionelles und carboxy-funktionelles PDMS kombiniert, um durch eine Salzbildung der beiden Funktionalitäten eine verbesserte Fixierung des carboxy-funktionellen Siloxans zu erreichen. Die Kombination zeigte bei einem Überschuss an amino-funktionellem PDMS eine gute Fixierung, jedoch ansonsten keine Synergieeffekte. Die Dimensionsstabilität des Holzes wurde durch die Behandlungen nur sehr geringfügig verbessert. Hierfür müsste eine gute Eindringung der Chemikalien in die Zellwand erfolgen und ein dauerhaftes Bulking erzielt werden. Die Eindringung der Chemikalien in die Zellwand war jedoch in allen Fällen nur gering.