Since 1998, the United States Green Building Council, via the Leadership in Energy and Environmental Design (LEED) standards, has established the premiere set of guidelines for construction ethics from the standpoint of eco-friendliness and occupant safety and health in the U.S. and around the world. These guidelines are skyrocketing in use due in part to two reasons: · increased awareness of a need for reducing, reusing, and recycling in order to save resources and natural areas for future generations; and, · increased amount of time spent indoors in work places and homes. The LEED guidelines encourage sustainable and responsible use of land, water, energy, and materials, and promote a safe and healthy environment through use of innovative designs and technology. As part of the responsible use of materials, the LEED guidelines encourage the use of rapidly renewable materials such as cotton, straw, wool, and cork as insulation products. Although these products can be produced naturally and quickly from nature, they are also cellulose or carbohydrate based products. Cellulose and carbohydrate based materials are typically optimal food sources for mold in the presence of moisture, ironically destroying facilities and creating poor living and work environments. Samples of wool, cork, straw, and cotton--rapidly renewable materials used as exterior wall insulation products--were exposed to different moisture amounts in an encapsulated environment, representing the environment within a wall cavity when exposed to water from pipes, leaks, condensation and absorption, or from initial construction. The samples were monitored over time for mold growth. The data logged from the samples were analyzed to determine the degree of mold susceptibility of each material. In addition, samples with increased amounts of moisture were examined to determine increased promotion of mold growth. The results from this study showed that all of the above mentioned materials were highly susceptible to mold growth and that the moisture amount did not increase the rate of mold growth. Based on the data collected from this study, recommendations were made to review the current use of rapidly renewable and other cellulose and carbohydrate based materials in wall construction.

No description available.

Numerous studies have focused on enhancing the flame retardant behavior of cotton and polyurethane foam. Some of the most commonly used treatments (e.g., brominated compounds) have raised concerns with regard to toxicity and environmental persistence. These concerns have led to significant research into the use of alternative approaches, including polymer nanocomposites prepared from more environmentally benign nanoparticles. These particles migrate to the surface from the bulk during fire exposure to form a barrier on the surface that protects the underlying polymer. This theory of fire suppression in bulk nanocomposites inspired the use of layer-by-layer (LbL) assembly to create nanocoatings in an effort to produce more effective and environmentally-benign flame retardant treatments. Negatively charged silica nanoparticles of two different sizes were paired with either positively charged silica or cationic polyethylenimine (PEI) to create thin film assemblies. When applying these films to cotton fabric, all coated fabrics retained their weave structure after being exposed to a vertical flame test, while uncoated cotton was completely destroyed. Micro combustion calorimetry confirmed that coated fabrics exhibited a reduced peak heat release rate, by as much as 20% relative to the uncoated control. Even so, this treatment would not pass the standard UL94 vertical flame test, necessitating a more effective treatment. Positively- charged chitosan (CH) was paired with montmorillonite (MMT) clay to create a renewable flame retardant nanocoating for polyurethane foam. This coating system completely stops the melting of a flexible polyurethane foam when exposed to direct flame from a butane torch, with just 10 bilayers (~ 30 nm thick). The same coated foam exhibited a reduced peak heat release rate, by as much as 52%, relative to the uncoated control. This same nanobrick wall coating is able to impart gas barrier to permeate plastic film. Multilayered thin films were assembled with "green" food contact approved materials (i.e., chitosan, polyacrylic acid (PAA) and montmorillonite clay). Only ten CH-PAA-CH-MMT quadlayers (~90 nm thick) cause polylactic acid (PLA) film to behave like PET in terms of oxygen barrier. A thirty bilayer CH-MMT assembly (~100 nm thick) on PLA exhibits an oxygen transmission rate (OTR) below the detection limit of commercial instrumentation (<= 0.005 cm^3/(m^2*day*atm)). This is the same recipe used to impart flame retardant behavior to foam, but it did not provide effective FR to cotton fabric, so a very different recipe was used. Thin films of fully renewable electrolytes, chitosan and phytic acid (PA), were deposited on cotton fabric in an effort to reduce flammability through an intumescent effect. Altering the pH of aqueous deposition solutions modifies the composition of the final nanocoating. Fabrics coated with highest PA content multilayers completely extinguished the flame and reduced peak heat release (pkHRR) and total heat release of 60% and 76%, respectively. This superior performance is believed to be due to high phosphorus content that enhances the intumescent behavior of these nanocoatings.

Developing renewable materials to reduce the dependence on fossil fuel as a feedstock for a wide range of applications is becoming increasingly acknowledged as important in society. Chitin, the second most abundant biopolymer in nature, is an ideal candidate for diverse applications because of its remarkable properties, such as abundance, renewability, biodegradability, biocompatibility, antibacterial activity, chemical functionality, and high stiffness and strength. Despite these inherent advantages, chitin is currently still underutilized mainly due to its strong molecular interactions, which make it insoluble in common solvents. Currently, its major applications are limited to biomedical engineering, such as tissue engineering, wound dressing and sutures. This thesis aims to explore and enable the potential utilization of chitin in other fields where it may serve as a renewable functional advanced material. Here, a number of novel chitin-based materials were developed successfully without employing chitin dissolution. These include chitin nanofibers (CNFs), porous chitin with tunable structures, chitin-reinforced polymer composites and chitin-stabilized aqueous foams. Moreover, the properties of these materials including interfacial, optical, thermal, and mechanical characteristics were determined, and their potential utilizations were demonstrated. Briefly, in chapter 2, CNFs with diameters of ~20 nm were successfully extracted from crab α-chitin by a high pressure homogenization process. The produced CNFs were dispersed well in water without forming strong network structures due to their electrostatic repulsions. The obtained CNF film has a high residue amount (40%) when heated up to 1000 ˚C. Meanwhile, it exhibited high optical transparency as well as great gas barrier properties. In chapter 3, on the basis of the obtained CNFs in chapter 2, versatile porous structures including oriented sheets and three-dimensional aperiodic nanofiber networks were achieved by using a freeze drying technique. Since the formation of nanofibrous structures cannot be predicted by the widely-used particle encapsulation model, a modified structure formation mechanism was proposed. In chapter 4, the structure-property relationships of the CNF/poly(ethylene oxide)(PEO) nanocomposites were established. We demonstrated that the CNFs formed network structures in PEO matrix and had hydrogen bonding interaction with PEO. The CNFs can greatly enhance the mechanical properties of PEO, such as elastic modulus and tensile strength. In chapter 5, the aqueous foams stabilized by high-aspect-ratio CNFs were developed. The created foams exhibited strong hindrance on film drainage, coalescence and disproportionation. The fibrillated CNFs alone were not able to stabilize air bubbles, but the addition of small amounts of valeric acids in CNF dispersion can make chitin foamable. The results clearly showed that valeric acid modified CNFs reduced the surface tension of aqueous dispersion and were attached at the air-water interface. Overall, this research has provided many new insights for the fabrication, characterization, and utilization of chitin, and has built a solid foundation for further exploiting chitin for diverse applications.

Na presente tese foram preparados poliésteres derivados de dois materiais renováveis o ácido 2,5-furanodicarboxílico (AFD) e a isoidida. Foram também preparados monômeros dihidroxílados para uso em poliesterificações e em reações com diisocianatos contendo um aduto de Diels-Alder (DA) formado pela reação de um grupo furano e uma maleimida (reação entre uma bismaleimida e o álcool furfurílico). Esses diois foram utilizados na preparação de poliésteres e poliuretanos termorreversíveis. A termorreversibilidade dos materiais preparados advém do fato de que os adutos de DA são termorreversíveis (rDA). Portanto, ao aquecer os poliésteres preparados com aduto-DA são originados monômeros difuncionais com grupos furano e/ou maleimida. O produto da rDA pode então ser repolimerizado, mas não via reações de poliesterificação ou isocianato/hidroxila, mas pelo acoplamento furano/maleimida (DA). Por fim uma nova rota para a obtenção de copolímeros aleatórios foi investigada. Essa rota consiste em provocar a rDA de uma mistura de dois homopolímeros distintos obtidos por polimerização em etapas contendo no interior de suas unidades repetitivas adutos de Diels-Alder e em seguida provocar a sua repolimerização via DA para dar origem a um copolímero aleatório. Os materiais foram caracterizados por suas estruturas químicas por Espectroscopia na região do infravermelho com transformada de Fourier (FTIR), ressonância magnética nuclear de próton (RMN ¹H). Foram feitos ensaios de cromatografia de permeação de gel (GPC), onde notou-se uma massa média numérica e ponderal para os poliésteres obtidos a partir do AFD e também para o poliéster e poliuretano termorreversíveis de aproximadamente 1600 g.mol¹. Nos ensaios de calorimetria exploratória diferencial (DSC) foi obtido Tgs variados para os poliésteres obtidos a partir do AFD indo de 88 a 159ºC, de 80ºC para o poliuretano termorreversível e de 106ºC para o poliéster termorreversível. Para a análise termogravimétrica (TGA) foi observado temperaturas de degradação para os poliésteres obtidos a partir do AFD em torno de 280ºC. Para a análise térmica dinâmico-mecânicas (DMTA) obteve-se Tg\'s em 117, 123 e 120ºC para o poliéster, o poliuretano e o copolímero termorreversíveis. / In this thesis it was prepared polyesters of two renewable monomers, the 2.5-furandicarboxylic acid and isoidide. Dihydroxy monomers were also prepared for use in polysterification and in reactions with diisocyanates, both containing Diels-Alder adduct in the molecule formed by the reaction of a furan group and a maleimide (reaction between bismaleimide and furfuryl alcohol). These diols were used in the preparation of thermoreversible polyesters and polyurethanes. The thermoreversibility of these materials comes from the fact that the DA adducts are thermoreversible (rDA). Therefore, heating these polymers give rise to difunctional monomers with an adduct-DA with furan and/or maleimide functions. The product of the rDA may then be polymerized not via polysterification reactions or isocyanate/hydroxyl, but by furan/maleimide coupling (DA) restoring the DA adduct. Finaly a new route to obtain random copolymers was investigated. This route consists in the rDA of a mixture of two different homopolymers obtained by polymerization in stages containing adducts producing monomers with furan and maleimide functions that can be polymerization via DA reaction to give a random copolymer. The materials were characterized by their chemical structures by infrared spectroscopy (FTIR), nuclear magnetic resonance of proton (¹H-NMR), gel permeation chromatography (GPC), experiments were made, where it was noticed a number and weight average mass for the polyesters obtained from the AFD and also for the thermoreversible polyester and polyurethane 1600 gmol¹. In differential scanning calorimetry tests (DSC) was obtained Tg\'s for various polyesters obtained from the AFD ranging from 88 to 159°C, 80°C for the thermoreversible polyurethane and 106°C for the thermoreversible polyester. For the thermogravimetric analysis (TGA) was observed degradation temperatures for the polyesters obtained from the AFD around 280°C. For dynamic mechanical thermal analysis (DMTA) Tg was obtained in 117, 123 and 120°C for polyester, polyurethane and copolymer thermoreversible.

Na presente tese foram preparados poliésteres derivados de dois materiais renováveis o ácido 2,5-furanodicarboxílico (AFD) e a isoidida. Foram também preparados monômeros dihidroxílados para uso em poliesterificações e em reações com diisocianatos contendo um aduto de Diels-Alder (DA) formado pela reação de um grupo furano e uma maleimida (reação entre uma bismaleimida e o álcool furfurílico). Esses diois foram utilizados na preparação de poliésteres e poliuretanos termorreversíveis. A termorreversibilidade dos materiais preparados advém do fato de que os adutos de DA são termorreversíveis (rDA). Portanto, ao aquecer os poliésteres preparados com aduto-DA são originados monômeros difuncionais com grupos furano e/ou maleimida. O produto da rDA pode então ser repolimerizado, mas não via reações de poliesterificação ou isocianato/hidroxila, mas pelo acoplamento furano/maleimida (DA). Por fim uma nova rota para a obtenção de copolímeros aleatórios foi investigada. Essa rota consiste em provocar a rDA de uma mistura de dois homopolímeros distintos obtidos por polimerização em etapas contendo no interior de suas unidades repetitivas adutos de Diels-Alder e em seguida provocar a sua repolimerização via DA para dar origem a um copolímero aleatório. Os materiais foram caracterizados por suas estruturas químicas por Espectroscopia na região do infravermelho com transformada de Fourier (FTIR), ressonância magnética nuclear de próton (RMN ¹H). Foram feitos ensaios de cromatografia de permeação de gel (GPC), onde notou-se uma massa média numérica e ponderal para os poliésteres obtidos a partir do AFD e também para o poliéster e poliuretano termorreversíveis de aproximadamente 1600 g.mol¹. Nos ensaios de calorimetria exploratória diferencial (DSC) foi obtido Tgs variados para os poliésteres obtidos a partir do AFD indo de 88 a 159ºC, de 80ºC para o poliuretano termorreversível e de 106ºC para o poliéster termorreversível. Para a análise termogravimétrica (TGA) foi observado temperaturas de degradação para os poliésteres obtidos a partir do AFD em torno de 280ºC. Para a análise térmica dinâmico-mecânicas (DMTA) obteve-se Tg\'s em 117, 123 e 120ºC para o poliéster, o poliuretano e o copolímero termorreversíveis. / In this thesis it was prepared polyesters of two renewable monomers, the 2.5-furandicarboxylic acid and isoidide. Dihydroxy monomers were also prepared for use in polysterification and in reactions with diisocyanates, both containing Diels-Alder adduct in the molecule formed by the reaction of a furan group and a maleimide (reaction between bismaleimide and furfuryl alcohol). These diols were used in the preparation of thermoreversible polyesters and polyurethanes. The thermoreversibility of these materials comes from the fact that the DA adducts are thermoreversible (rDA). Therefore, heating these polymers give rise to difunctional monomers with an adduct-DA with furan and/or maleimide functions. The product of the rDA may then be polymerized not via polysterification reactions or isocyanate/hydroxyl, but by furan/maleimide coupling (DA) restoring the DA adduct. Finaly a new route to obtain random copolymers was investigated. This route consists in the rDA of a mixture of two different homopolymers obtained by polymerization in stages containing adducts producing monomers with furan and maleimide functions that can be polymerization via DA reaction to give a random copolymer. The materials were characterized by their chemical structures by infrared spectroscopy (FTIR), nuclear magnetic resonance of proton (¹H-NMR), gel permeation chromatography (GPC), experiments were made, where it was noticed a number and weight average mass for the polyesters obtained from the AFD and also for the thermoreversible polyester and polyurethane 1600 gmol¹. In differential scanning calorimetry tests (DSC) was obtained Tg\'s for various polyesters obtained from the AFD ranging from 88 to 159°C, 80°C for the thermoreversible polyurethane and 106°C for the thermoreversible polyester. For the thermogravimetric analysis (TGA) was observed degradation temperatures for the polyesters obtained from the AFD around 280°C. For dynamic mechanical thermal analysis (DMTA) Tg was obtained in 117, 123 and 120°C for polyester, polyurethane and copolymer thermoreversible.

Guadua angustifolia Kunth (Guadua) is a bamboo species native to South and Central America that has been widely used for structural applications in small and large-scale buildings, bridges and temporary structures. Currently, its structural use is regulated within seismic resistant building codes in countries such as Peru and Colombia. Nevertheless, Guadua remains a material for vernacular construction associated with high levels of manual labour and structural unpredictability. Guadua buildings are limited to two storeys due to the overall flexibility of the slender and hollow culms and its connection systems. Its axial specific stiffness is comparable to that of steel and hardwoods, but unlike wood, Guadua’s hollow structure and lack of ray cells render it prone to buckling along the grain and to transverse crushing. As a result, Guadua’s mainstream use in construction and transformation into standard sizes or engineered Guadua products is scarce. Therefore, this work focussed on the development of standardised flat industrial structural products from Guadua devising replicable manufacturing technologies and engineering methods to measure and predict their mechanical behaviour. Cross-laminated Guadua panels were developed using thermohydro-mechanically modified and laminated flat Guadua strips glued with a high performance resin. Guadua was subjected to thermo-hydro-mechanical (THM) treatments that modified its microstructure and mechanical properties. THM treatment was applied to Guadua with the aim of tackling the difficulties in the fabrication of standardised construction materials and to gain a uniform fibre content profile that facilitated prediction of mechanical properties for structural design. Densified homogenous flat Guadua strips (FGS) were obtained. Elastic properties of FGS were determined in tension, compression and shear using small-clear specimens. These properties were used to predict the structural behaviour of G-XLam panels comprised of three and five layers (G-XLam3 and G-XLam5) by numerical methods. The panels were assumed as multi-layered systems composed of contiguous lamellas with orthotropic axes orientated at 0º and 90º. A finite element (FE) model was developed, and successfully simulated the response of G-XLam3 & 5 panels virtually loaded with the same boundary conditions as the following experimental tests on full-scale panels. G-XLam3 and G-XLam5 were manufactured and their mechanical properties evaluated by testing large specimens in compression, shear and bending. Results from numerical, FE predictions and mechanical testing demonstrated comparable results. Finally, design and manufacturing aspects of the G-XLam panels were discussed and examples of their architectural and structural use in construction applications such as mid-rise buildings, grid shells and vaults are presented. Overall, this research studies THM treatments applied to Guadua in order to produce standardised engineered Guadua products (EGP), and provides guidelines for manufacturing, testing, and for the structural analysis and design with G-XLam panels. These factors are of key importance for the use of Guadua as a mainstream material in construction.

Due to environmental concerns and to the limited amount of fossil fuel in the world theinterest in using renewable material has been and will continue to be on the rise. With theincreasing demand for renewable materials such as bio-based fibers, the research aroundnatural fibers is intensifying. Abaca (Musa Texitilis Nee) is a plant endemic to the Philippineswhich is claimed to contain the strongest natural fiber in the world 1. However, no thoroughresearch on performing tensile strength test on single abaca fibers/cells has been found. Byperforming tensile strength test on the single abaca fibers and relate this will provide freshdata about the single abaca fiber strength that can be compared with other natural fibers.This can later be a reference tool in order to find the optimal fiber for the product to be made. The purpose of this study is to develop a methodology for performing tensile strength testson single abaca fibers with the major objective to relate the tensile strength and E-modulusof the fibers with their microfibrillar angle (MFA). The research was done by using Abaca(grade S2) from Camarines Sur (Philippines) that was chemically disintegrated in order toobtain single fibers. The single fibers were mounted to a custom made paper frame for thetensile strength test performed by an Instron 5944. The MFA of each fiber was also retrievedusing an optical microscope with a polarized filter. The research showed an indication of aninversely proportional relation between MFA and tensile strength of the fibers. According tothe results, the E-modulus of the single abaca fiber was almost constant, independently onthe MFA of the fiber. / The purpose of this study is to do a broad map out of the abaca industry in the Philippines. Furthermore, the study aims to provide an overview of the abaca industry as a tool for finding ways to optimize the fiber production and to find suggestions on how to make a bigger share of the profit from the abaca products to stay by the farmers in the Philippines. The objectives are therefore also focused on describing the way the abaca plant is cultivated, harvested, processed, and further distributed from the farms. Also, the objectives are to describe the abaca supply and demand situation along with identifying challenges for abaca production. Today the outmoded abaca production in the Philippines is experiencing a productivity loss which makes the farmers' incomes unnecessarily low. Important factors that, by this study, have been identified affecting the low productivity and profit are lack of proper farming management, distribution and unoptimized usage of the fibers. A big share of the abaca fibers produced is also being exported. This means that the raw fibers are being made into high-value products abroad and hence the profit to be made is dislocated further from the farmers with low means of improving their standard of living. The study has been performed by doing a literature study complemented with interviews and visits to abaca farmers and other stakeholders within the abaca industry.

In the aftermath of natural disasters, providing temporary housing to displaced people is essential to alleviate human suffering. However, in some cases, the chosen post-disaster temporary housing strategy may not be suitable for the local conditions, which can worsen the negative impacts, particularly when decision-makers need to change their original plan due to the uncertainty of post-disaster conditions. As most temporary housing design strategies have their weaknesses, the best approach is the one that matches the specific circumstances of each scenario. This thesis proposes design strategies, including prefabricated and modular units, foldable units, upgradable units, grid and linear expansion, and passive energy units, to determine the most appropriate policy to minimize conflicts between local requirements and temporary housing characteristics while maximizing the comfort and sustainability of temporary housing design. The strategies were analyzed based on their strength and weaknesses by following the previous research, and their implementation possibilities on recently occurred natural disasters, e.g., Turkey's earthquake in 2023, were also evaluated. It was found that all strategies except for grid and linear expansion might be suitable for the studied natural disaster.

Le remplacement de monomères d'origine pétrosourcée par des analogues biosourcés améliore la durabilité et diminue la dépendance aux ressources fossiles. De plus, de nouvelles caractéristiques et propriétés sont souvent découvertes. Les polyesters aliphatiques biosourcés ont déjà partiellement remplacé les produits traditionnels. Dans le contexte du projet Sorago, une résine entièrement biosourcée pour les revêtements de prélaquage des produits intérieurs a déjà été introduite sur le marché (Estetic® bio Air, Arcelor Mittal). Pour permettre l'utilisation du produit dans des applications extérieures, sa résistance à la lumière UV et à l'humidité sont à améliorer. Cela pose deux problèmes : Une disponibilité limitée de monomères pouvant introduire de la rigidité dans la résine et la relation entre la structure de la résine et sa dégradation. La vanilline a été choisie comme synthon pour la gamme des monomères rigides et biosourcées. La transformation de sa fonction aldehyde par réaction de Perkin et sa réactivité a été examinée. Dans une série des copolymerisations, l'influence des conditions de réaction sur la composition du produit final a été proposée. Une relation structure-propriétés concernant la température de la transition vitreuse et la viscoélasticité des plusieurs monomères biosourcées a été établie, et comparée avec celle des monomères petrosourcées. Une série des prototypes avec des propriétés très variées a été soumise à un test de vieillissement rapide. Leur dégradation a été suivie sur la base de leur rétention de brillance, par FTIR et par des tests de µ-dureté et d'épaisseur des films. La performance des prototypes biosourcés s'est révélée inférieure à celle d'une résine standard pétrosourcée mais aucune évidence qui suggère que cela est du à la présence des monomères biosourcées n'a été détectée. Cela suggère que la création d'une résine biosourcée et suffisamment durable pour l'extérieur sera possible / Moving away from petroleum and towards biobased materials not only leads to greater sustainability and lower dependence on diminishing fossil resources, but can also catalyse the discovery of new properties. Aliphatic polyesters based on renewable resources have already started to replace traditional products. Within the Sorago project, a fully biobased resin for interior coil coatings has recently been proposed on the market (Estetic® Bio Air, Arcelor Mittal). In order to extend the possible use of the biobased product to exterior applications, an improvement of its resistance to humidity and UV radiation is crucial. This presents two challenges: The limited availability of monomers which provide rigidity in the resin structure and the relationship between the resin composition and its weatherability. Vanillin was chosen as a possible extension to the range of rigid, biobased monomers for polyesterification reactions. The transformation of its aldehyde and its reactivity was studied in terms of catalytic activation and through a series of copolymerisations which revealed the influence of the reaction conditions on the composition of the product. A structure-property relationship concerning the coating glass transition temperature and visco-elastic behaviour of the coating was furthermore established for a series of renewable monomers and contrasted with petroleum based equivalents. Series of prototypes with a wide variety of properties were then subjected to accelerated weathering tests. Their degradation was followed directly by gloss retention and different mechanisms were revealed using FTIR, µ-hardness and film thickness measurements. While the performance of the biobased coating was subpar, no evidence linking its degradation to the presence of renewable monomers was found, suggesting that the creation of a sufficiently durable and renewable exterior coating will be possible