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The Use Of New Aqueous Chemical Wood Modifications To Improve The Durability Of Wood Plastic Composites
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Book Synopsis The Use of New, Aqueous Chemical Wood Modifications to Improve the Durability of Wood-plastic Composites by : Rebecca E. Ibach
Download or read book The Use of New, Aqueous Chemical Wood Modifications to Improve the Durability of Wood-plastic Composites written by Rebecca E. Ibach and published by . This book was released on 2017 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: S2The wood flour used in wood-plastic composites (WPCs) can biologically deteriorate and thus the overall mechanical performance of WPCs decrease when exposed to moisture and fungal decay. Protecting the wood flour by chemical modification can improve the durability of the wood in a nontoxic way so it is not harmful to the environment. WPCs were made with modified wood flour and then evaluated for moisture sorption, fungal resistance and mechanical performance. Two different chemical modifications at 2 different levels were used: organosilicate (OS, 1% and 2.5%) and cobalt sulfate (CoS, 2.5% and 5%). All modifications had less weight loss than the unmodified controls with the 2.5% OS blend showing no weight loss from decay by either brown or white rot fungi. Water soaking for 1-week at elevated temperature (70°C) was more aggressive for laboratory decay and mechanical testing as shown by higher weight loss and lower mechanical properties compared to 2-week water soaking at room temperature (23°C). Moisture exposure decreased the mechanical properties, but 2.5% OS, 2.5% CoS and 5% CoS had better performance than the unmodified controls and 1% OS after 70°C conditioning and decay."
Book Synopsis Wood Modification Technologies by : Dick Sandberg
Download or read book Wood Modification Technologies written by Dick Sandberg and published by CRC Press. This book was released on 2021-07-15 with total page 765 pages. Available in PDF, EPUB and Kindle. Book excerpt: The market for durable products using modified wood has increased substantially during the last few years. This is partly because of the restriction on the use of toxic preservatives due to environmental concerns, and to lower maintenance cost and time. Furthermore, as sustainability becomes a greater concern, the environmental impact of construction and interior materials is factored in planning by considering the whole life cycle and embodied energy of the materials used. Wood is modified to improve its intrinsic properties, enhance the range of applications of timber, and to acquire the form and functionality desired by engineers without calling the environmental friendliness into question. Wood modification processes are at various stages of development, and the challenges faced in scaling up to industrial applications differ. The aim of this book is to put together the key elements of the changes of wood constituents and the related changes in wood properties of modified wood. Further, a selection of the principal technologies implemented in wood modification are presented. This work is intended for researchers, professionals of timber construction, as well as students studying the science of materials, civil engineering and architecture. This work is not exhaustive, but intends to deliver an outline of the scientific disciplines necessary to apprehend the technologies of wood modification and its behavior during treatment, as well as during its use.
Book Synopsis Moisture and Fungal Durability of Wood-plastic Composites Made with Chemically Modified and Treated Wood Flour by : B. Kristoffer Segerholm
Download or read book Moisture and Fungal Durability of Wood-plastic Composites Made with Chemically Modified and Treated Wood Flour written by B. Kristoffer Segerholm and published by . This book was released on 2013 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evaluating the fungal durability of wood-plastic composites (WPCs) is complicated by the influence of slow moisture sorption. Recently, the American Wood Protection Association (AWPA) Standard Method E10, Testing Wood Preservatives by Laboratory Soil-Block Cultures, was modified to incorporate not only solid wood, but also wood-based composites and WPCs. To simulate long term WPC performance, conditioning of the specimens is now required prior to fungal exposure to increase the moisture content of the specimens. The moisture and fungal durability, as well as the mechanical properties, of two different WPCs were investigated in the laboratory following this new AWPA E10-12 Standard. Wood flour was modified with acetic anhydride and then extruded with high density polyethylene (HDPE). Wood flour was treated with an isothiazolone-based solution and then injected molded with polypropylene (PP). WPCs were conditioned by water soaking either 2 weeks at 22 C or 5 days at 70 C. Weight and moisture content of the WPCs were monitored. Results showed that the acetylation decreased the moisture sorption of the WPCs and showed no mass losses due to decay. The WPC with an isothiazolone-based solution did not show any mass losses due to fungal decay.
Book Synopsis Handbook of Wood Chemistry and Wood Composites by : Roger M. Rowell
Download or read book Handbook of Wood Chemistry and Wood Composites written by Roger M. Rowell and published by CRC Press. This book was released on 2005-02-18 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: The degradable nature of high-performance, wood-based materials is an attractive advantage when considering environmental factors such as sustainability, recycling, and energy/resource conservation. The Handbook of Wood Chemistry and Wood Composites provides an excellent guide to the latest concepts and technologies in wood chemistry and bio-based composites. The book analyzes the chemical composition and physical properties of wood cellulose and its response to natural processes of degradation. It describes safe and effective chemical modifications to strengthen wood against biological, chemical, and mechanical degradation without using toxic, leachable, or corrosive chemicals. Expert researchers provide insightful analyses of the types of chemical modifications applied to polymer cell walls in wood, emphasizing the mechanisms of reaction involved and resulting changes in performance properties. These include modifications that increase water repellency, fire retardancy, and resistance to ultraviolet light, heat, moisture, mold, and other biological organisms. The text also explores modifications that increase mechanical strength, such as lumen fill, monomer polymer penetration, and plasticization. The Handbook of Wood Chemistry and Wood Composites concludes with the latest applications, such as adhesives, geotextiles, and sorbents, and future trends in the use of wood-based composites in terms of sustainable agriculture, biodegradability and recycling, and economics. Incorporating over 30 years of teaching experience, the esteemed editor of this handbook is well-attuned to educational demands as well as industry standards and research trends.
Book Synopsis Wood Modification by : Callum A. S. Hill
Download or read book Wood Modification written by Callum A. S. Hill and published by John Wiley & Sons. This book was released on 2007-02-06 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is exclusively concerned with wood modification, although many of these processes are generic and can be applied to other lignocellulosic materials. There have been many rapid developments in wood modification over the past decade and, in particular, there has been considerable progress made in the commercialisation of technologies. Topics covered include: The use of timber in the 21st century Modifying the properties of wood Chemical modification of wood: Acetic Anhydride Modification and reaction with other chemicals Thermal modification of wood Surface modification Impregnation modification Commercialisation of wood modification Environmental consideration and future developments This is the first time that a book has covered all wood modification technologies in one text. Although the book covers the main research developments in wood modification, it also puts wood modification into context and additionally deals with aspects of commercialisation and environmental impact. This book is very timely, because wood modification is undergoing huge developments at the present time, driven in part by environmental concerns regarding the use of wood treated with certain preservatives. There has been considerable commercial interest shown in wood modification over the past decade, with products based upon thermal modification, and furfurylation now being actively being marketed. The next few years will see the commercialisation of acetylation and impregnation modification. This is a new industry, but one that has enormous potential. This book will prove useful to all those with an interest in wood modification including researchers, technologists and professionals working in wood science and timber engineering, wood preservation, and well as professionals in the paper and pulp industries, and those with an interest in the development of renewable materials.
Book Synopsis Bondability of modified wood by : Alireza Bastani
Download or read book Bondability of modified wood written by Alireza Bastani and published by Cuvillier Verlag. This book was released on 2016-06-30 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates the bonding properties of modified wood by considering three different aspects: water related characteristics, mechanical performance and optical (fluorescence microscopy and X-ray micro-computed tomography) observation of adhesive penetration into modified wood structure. In recent years, the new wood modifications have become more commercially available in the market for both exterior and interior applications due to improved properties that modification can bring to the wood e.g. the improved biological durability, dimensional stability, hardness and weathering resistance of the wood as well as the environmentally friendly nature of the wood modification processes (Militz and Hill 2005). Besides these advantages, modification can affect some technological aspects of the wood such as its bonding performance. For example, it can alter the strength of adhesion as a result of changes in chemical, physical and structural characteristics of the wood. For example, the less polar and less porous modified wood surfaces can result in reduced adhesion due to formation of less free OH groups for bonding leading to poorer adhesive wetting of the wood surface and weaker chemical bonds between the two adherents (Hunt et al. 2007). As modified wood becomes a more demanded material for different applications, there is a need to study its bonding performance where the challenge is to bond different modified materials as their physical and chemical characteristics are substantially changed by modification. In this thesis, measurements of capillary water uptake, contact angle and surface energy were used to determine the water related properties and hydrophobic behavior of furfurylated (FA40 and FA70, which represent 65 and 75 % WPGs) and N-methylol melamine (NMM) (10, 20 and 30%) modified Scots pine and thermally treated Scots pine and beech (modified through an industrial scale vacuum press dewatering method at 195 and 210 °C). The capillary water uptake results indicated a considerable reduction of water uptake for all modifications in all directions both after short (24 h) and long contact times (168, 336 h). Contact angle measurement data revealed an increased hydrophobicity of modified wood. However, some exceptions were observed, mainly for thermally treated wood. Modifications provided radial and tangential surfaces with a non-polar character. Penetration of adhesives into the wood structure plays an important role in the production of glued wood-based panels and products by affecting the bond quality (Frihart 2005, Kamke and Lee 2007). The gross penetration of emulsion polymer isocyanate (EPI), polyurethane (PU) and polyvinyl acetate (PVAc) adhesives into modified wood, both with and without pressure, were determined by using fluorescence microscopy based on measurements of effective (EP) and maximum penetration (MP). Without application of pressure, the EP of EPI adhesive reduced after NMM modification and furfurylation (FA70) and also PU adhesive after NMM modification while the EP of PVAc adhesive increased into furfurylated and NMM modified (10 and 20%) wood. For thermally treated Scots pine, increasing the treatment temperature improved EP of all adhesives. Among used adhesives, PU penetrated much deeper into thermally treated wood for both treatment temperatures. Comparison of penetration of adhesive with and without pressure revealed that with the exception of EP of PU and EPI adhesives into NMM-modified wood and PVAc into thermally treated beech at 195°C, application of pressure led to rather different results as compared to the EP data when no pressure was applied. Visual observation and analysis of fluorescence microscopy photomicrographs provided more detailed information on modality of penetration. Due to the large and deep penetration of PU adhesive into thermally treated Scots pine observed in both studies (with and without pressure), the 3D pattern of penetration of this adhesive was obtained by X-ray micro- computed tomography indicating the pathways which were used by this adhesive for penetration. In another study, the bonding shear strength of the same modified wood materials glued with the same adhesives was also investigated. For all adhesives used, the shear strength significantly reduced after furfurylation and NMM modification of Scots pine samples, mainly due to the brittle nature of the wood after modification rather to the failure of the bondline. Bonding strength of both Scots pine and beech was also negatively affected by thermal modification and the bondline was found to be the weakest link in thermally modified wood. The EP of adhesives and the bondline thickness did not relate to the shear strength of all modified wood materials. It was indicated that the lower shear strength of modified wood could be attributed to other factors, such as the decreased chemical bonding or mechanical interlocking of adhesives, and the reduced strength of brittle modified wood substrate. The effect of two important bonding variables, wood moisture content and open assembly time on penetration of PU adhesive into thermally modified wood (195 and 210 °C) was also studied. The equilibrium moisture content (EMC) level of 8.6% was found to be the optimum for an effective penetration of PU adhesive in thermally modified Scots pine treated at 195°C. In most of the cases, penetration of PU adhesive did not change significantly by increasing the open assembly time, which suggested using a shorter open assembly time of 15 min than 30 min for bonding of thermally modified Scots pine with PU adhesive, in order to save time and reducing the production costs. For samples treated at both treatment temperatures and after shorter open assembly time, the highest MP values observed at moderate EMC levels of 8.6 and 8.2% and the lowest at the higher EMC levels of 13.2 and 12.5%. In another study, the effect of phenol formaldehyde (PF) treatment on bonding performance of beech glued with PVAc and phenol resorcinol formaldehyde (PRF) adhesives was also investigated. The results of both dry and wet conditions indicated higher shear strength for samples bonded with PRF than PVAc. With the exception of 25% PF treated wood bonded with PVAc, the PF modified wood can be glued with both adhesives satisfactorily under dry condition, while under wet condition only the 25% PF modified samples bonded with PRF provided acceptable bonding. For both adhesive systems, PF modification caused a reduction of adhesive penetration into wood structure, especially in the case of higher load treatment. The development of bonding strength of modified birch veneers glued with hot curing phenol formaldehyde (PF) adhesive was investigated in different pressing (20 s , 160s) and open assembly times (20s , 10 min). Generally, the bonding strength improved by extending the pressing time. In 20 s pressing, increasing assembly time did not change the bonding strength in most of the cases while at 160 s pressing, prolongation of assembly time developed a better bonding for controls, NMM modified and thermally treated veneers at 180°C. The combination of 10 min assembly time and 160 s pressing time provided the highest bonding strength for controls, NMM modified and thermally treated veneers at 180°C while furfurylated samples achieved the highest values in 20 s assembly and 160 s pressing times. In general, modification affected negatively the bonding performance of the veneers, especially for furfurylated and NMM modified samples. In General, the overall results obtained in this thesis showed that modified wood has lower bonding ability and performance than unmodified wood as result of the decreased water related properties, less penetration of adhesive into wood structure and decreased bonding strength after modification. However, the increased dimensional stability and low water uptake of modified wood might lead to better performance in long term.
Book Synopsis Handbook of Wood Chemistry and Wood Composites, Second Edition by : Roger M. Rowell
Download or read book Handbook of Wood Chemistry and Wood Composites, Second Edition written by Roger M. Rowell and published by CRC Press. This book was released on 2012-09-06 with total page 707 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wood has played a major role throughout human history. Strong and versatile, the earliest humans used wood to make shelters, cook food, construct tools, build boats, and make weapons. Recently, scientists, politicians, and economists have renewed their interest in wood because of its unique properties, aesthetics, availability, abundance, and perhaps most important of all, its renewability. However, wood will not reach its highest use potential until we fully describe it, understand the mechanisms that control its performance properties, and, finally, are able to manipulate those properties to give us the desired performance we seek. The Handbook of Wood Chemistry and Wood Composites analyzes the chemical composition and physical properties of wood cellulose and its response to natural processes of degradation. It describes safe and effective chemical modifications to strengthen wood against biological, chemical, and mechanical degradation without using toxic, leachable, or corrosive chemicals. Expert researchers provide insightful analyses of the types of chemical modifications applied to polymer cell walls in wood. They emphasize the mechanisms of reaction involved and resulting changes in performance properties including modifications that increase water repellency, fire retardancy, and resistance to ultraviolet light, heat, moisture, mold, and other biological organisms. The text also explores modifications that increase mechanical strength, such as lumen fill, monomer polymer penetration, and plasticization. The Handbook of Wood Chemistry and Wood Composites concludes with the latest applications, such as adhesives, geotextiles, and sorbents, and future trends in the use of wood-based composites in terms of sustainable agriculture, biodegradability and recycling, and economics. Incorporating decades of teaching experience, the editor of this handbook is well-attuned to educational demands as well as industry standards and research trends.
Book Synopsis Wood-Polymer Composites by : K O Niska
Download or read book Wood-Polymer Composites written by K O Niska and published by Elsevier. This book was released on 2008-05-29 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wood-polymer composites (WPC) are materials in which wood is impregnated with monomers that are then polymerised in the wood to tailor the material for special applications. The resulting properties of these materials, from lightness and enhanced mechanical properties to greater sustainability, has meant a growing number of applications in such areas as building, construction and automotive engineering. This important book reviews the manufacture of wood-polymer composites, how their properties can be assessed and improved and their range of uses.After an introductory chapter, the book reviews key aspects of manufacture, including raw materials, manufacturing technologies and interactions between wood and synthetic polymers. Building on this foundation, the following group of chapters discusses mechanical and other properties such as durability, creep behaviour and processing performance. The book concludes by looking at orientated wood-polymer composites, wood-polymer composite foams, at ways of assessing performance and at the range of current and future applications.With its distinguished editors and international team of contributors, Wood-polymer composites is a valuable reference for all those using and studying these important materials. Provides a comprehensive survey of major new developments in wood-polymer composites Reviews the key aspects of manufacture, including raw materials and manufacturing technologies Discusses properties such as durability, creep behaviour and processing performance
Book Synopsis Influence of Wood Modification on the Properties of Polyvinyl Chloride based Wood Polymer Composites (WPC) by : Marcus Müller
Download or read book Influence of Wood Modification on the Properties of Polyvinyl Chloride based Wood Polymer Composites (WPC) written by Marcus Müller and published by Cuvillier Verlag. This book was released on 2012-07-11 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract The study investigated the influences of wood modification on the properties of Polyvinyl chloride (PVC) based Wood Polymer Composites (WPC). Various ethanolamines, L-arginine, pre-hydrolyzed and monomeric aminosilane, melamine and acetic anhydride treatment were used to improve the adhesion between wood and polymer as well as water absorption behavior and resistance to basidiomycetes. Amine based treatments were chosen to change the nature of wood from acidic to basic in order to increase the compatibility with the acidic polymer. Treated and untreated wood flour, PVC and additives were dry blended in a mixer. The dry blend was compounded to granulate by counter-rotating twin screw extrusion and compression moulded into panels using a hydraulic press. Elemental analysis (nitrogen content) via gas chromatography showed expected fixation of aminosilane and melamine treatment. The nitrogen fixation of ethanolamine and L-arginine treated material were obviously reduced, whereas the amount and reactivity of the aminogroups influenced the fixation behavior. With increasing content of amino-groups and reactivity, the fixation was improved. Fourier transform infrared (FTIR) analyses revealed interactions between monoethanolamine and cell wall components. The amine based treatments changed the nature of wood from acidic to basic. An improvement of the interphase was detected via mechanical property testing. Tensile strength, elongation at break and unnotched impact strength of the composite were obviously increased by Larginine, ethanolamine and aminosilane treatments. It has to be considered that amine based treatments (monoethanolamine in this study) led to reduced thermal stability of the composite. Thermogravimetric analysis showed a decrease of onset temperature with increasing monoethanolamine content. Water repellence of the composite was improved by melamine, pre-hydrolyzed aminosilane and acetic acid treatment. Treated and untreated composites revealed high resistance against basidiomycetes. Due to the low initial moisture content and low weight loss of untreated and treated composites, no effect of the various modifications was distinguished. In general it is possible to treat/modify PVC/wood flour composites with used processing and chemical agents. Amine based treatments indicate an improved adhesion between wood and polymer and can be used as coupling agents. Acetic anhydride, melamine and prehydrolyzed aminosilane treatments improved water absorption behavior. Zusammenfassung In der vorliegenden Arbeit wurden die Auswirkungen verschiedener Holzmodifizierungen auf die Eigenschaften von Polyvinylchlorid (PVC) basierten Holz-Kunststoff Kompositen untersucht. Der Fokus lag dabei auf Verbesserung der Interphase zwischen Holz und Polymer, sowie einer Reduktion der Wasseraufnahme und einer Erhöhung der biologischen Dauerhaftigkeit des Komposits. Als Modifizierungschemikalien wurden Ethanolamine (Mono-, Di-, Triethanolamin), L-Arginin, Aminosilane, Melamin und Essigsäureanhydrid verwendet. Die eingesetzten Aminosilane unterschieden sich hinsichtlich ihrer Molekülgröße vor der Behandlung (Monomer, vor-hydrolisiert). Amin basierte Chemikalien wurden ausgewählt, um die Ladungseigenschaften des Holzes zu verändern. Eine bessere Kompatibilität zwischen dem sauren Polymer und der basisch modifizierten Holzoberfläche sollte dementsprechend erreicht werden. Das behandelte und unbehandelte Holzmehl wurde mit dem PVC und ausgewählten Additiven im Heiz-Kühl Mischer zu einem Trockengemisch verarbeitet. Das Trockengemisch wurde in einem gegenläufigen Doppelschneckenextruder granuliert und anschließend im Heißpressverfahren zu Platten gepresst. Mittels einer gaschromatischen Elementaranalyse wurde der Stickstoffgehalt der Holzmehlproben ermittelt, um Aussagen über die Fixierung der jeweiligen Chemikalie treffen zu können. Aminosilan und Melamin behandelte Proben zeigten die erwarteten Fixierungswerte. Die Stickstofffixierung der Ethanolamin und L-Arginin behandelten Proben war im Vergleich dazu deutlich reduziert. Allerdings wurde beobachtet, dass mit steigender Aminogruppenanzahl und Reaktivität auch die Fixierung zunahm. In Fourier Transform Infrarot (FTIR) Analysen wurden Interaktionen zwischen Monoethanolamin und den chemischen Zellwandkomponenten beobachtet. Zudem führte die Behandlung mit Aminosilanen, Ethanolaminen und dem L-Arginin zu einer pH-Wert Verschiebung. Die behandelten Proben besaßen basische Eigenschaften. Eine Verbesserung der Interphase wurde nach der Durchführung mechanischer Eigenschaftsprüfungen gemessen. Die Zugfestigkeit, Bruchdehnung und Schlagzähigkeit der Komposite wurden deutlich erhöht, wenn das Holzmehl zuvor mit Aminosilanen, Ethanolaminen oder L-Arginin behandelt wurde. Allerdings wurde die thermische Stabilität des Komposits durch die Behandlung (Monoethanolamin) herabgesetzt. Thermogravimetrische Analysen (TGA) zeigten eine reduzierte Zersetzungstemperatur mit steigendem Monoethanolamingehalt. Die Behandlung mit Essigsäureanhydrid und Melamin führte zu einer Verringerung der Wasseraufnahmegeschwindigkeit, sowie zu einer Reduzierung der maximalen Materialfeuchte. Bezüglich der verwendeten Aminosilane wurde nur bei der vor-hydrolisierten Variante eine Verbesserung des Wasseraufnahmeverhaltens beobachtet. Alle Komposite wiesen eine hohe Resistenz gegenüber Basidiomyceten auf. Aufgrund der niedrigen Feuchtegehalte vor Versuchsbeginn und den geringen Masseverlusten wurden keine Effekte der jeweiligen Behandlung festgesellt. Prinzipiell ist es möglich mit den verwendeten Chemikalien und Verarbeitungsverfahren Modifizierungen an PVC basierten Holz-Kunststoff Kompositen durchzuführen. Amin basierte Behandlungen zeigten eine erhöhte Kompatibilität mit dem Polymer, womit sie grundsätzlich als Haftvermittler eingesetzt werden können. Zudem wurde das Wasseraufnahmeverhalten der Komposite durch die Behandlung mit Essigsäureanhydrid, Melamin und vorhydrolisiertem Aminosilan positiv beeinflusst.
Book Synopsis Improvement of selected properties of Wood-Polymer Composites (WPC) – Silane modification of wood particles by : Timo Grüneberg
Download or read book Improvement of selected properties of Wood-Polymer Composites (WPC) – Silane modification of wood particles written by Timo Grüneberg and published by Cuvillier Verlag. This book was released on 2010-11-22 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wood Polymer Composites are a new group of hybrid materials, which combine the advantages of synthetic polymers such as polyolefines and natural polymers such as wood; whereas the synthetic polymer is used as matrix material and the wood as reinforcement material or filler. As matrix material, principally every thermoplastic polymer with a processing temperature below 200°C can be used due to the temperature sensivity of wood. Wood Polymer Composites are processed typically with processing technologies from the plastic industry such as extrusion and injection molding. The present study was conducted to explore the possibility of wood particle modification with different types of silanes. It was the aim to contribute the silanes as compatibilizers or coupling agent and therefore improve the mechanical properties and the resistance against water. Norway spruce (Picea abies) as representative wood species was used in three different particle types. The size distribution for the wood particles ranges from 70-2500 µm. Four commercial available silanes with various functional groups (amino, di-amino, alkyl) were used as modification agents. The concentrations varied between 1.5%, 3.0%, 4.5% and 7.5%. As reference system commonly used maleated acid anhydride based coupling agents were used. The pre-treated wood particles were compounded via extrusion with polypropylene and samples were produced via injection and compression molding. The following properties were tested; tensile, bending, and impact strength, water uptake (cold and boiling water test), descent rate, weathering tests and durability test against basidiomycetes. SEM-EDX investigations proved the presence of silane either in the cell wall structure, or on the wood particle surface. Due to the structure and the functionality of the silanes it was expected that the silane treated wood particles are able to improve the mechanical properties. It was shown that the silanes had no significant effect as compatibilizer or coupling agent. The mechanical properties strongly increase with the usage of coupling agent. Both coupling agents were based on maleic acid anhydride grafted on a polymer backbone, whereas Type I reaches an optimum regarding the mechanical properties at 3%, the coupling agent Type II still improves the mechanical properties up to a ratio of 4.5% with no clear optimum. The silane pretreatment influences the improvement not significantly, compare to the improvement caused by the coupling agent. The used wood particles showed mechanical degradation during the compounding process. The biggest degradation was monitored for the wood particles of Lignocel® Type 9. Due to its fine structure it can be assumed that the Arbocel® C100 wood particles consist of only cell wall fragments of the wooden cell wall, which express a better resistance against mechanical destruction during the process. The Wood Polymer Composites showed a lower decay rate compared to solid wood. The moisture content within the Wood Polymer Composite samples ranges at the low optimum level for fungi attack and were not significantly improved by an accelerated wetting before the test. The core remains relatively dry. The main protection seems to come from the encapsulation by the polymer. The weathered Wood Polymer Composite samples showed a strong color change within a relatively short period of exposure. The color changed independently from the silane type or the silane ratio. Also an increase of cracks and gaps on the sample surface was observed compared to the unexposed sample and the pure polymer reference.
Book Synopsis Chemical Modification of Wood Fiber to Enhance the Interface Between Wood and Polymer in Wood Plastic Composites by : Smith T. Sundar
Download or read book Chemical Modification of Wood Fiber to Enhance the Interface Between Wood and Polymer in Wood Plastic Composites written by Smith T. Sundar and published by . This book was released on 2005 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Recent Advances in the Processing of Wood-Plastic Composites by : Jin Kuk Kim
Download or read book Recent Advances in the Processing of Wood-Plastic Composites written by Jin Kuk Kim and published by Springer Science & Business Media. This book was released on 2010-12-16 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wood-plastic composite (WPC) is a non-recyclable composite material lumber or timber made of recycled plastic and wood wastes which has become one of the most dynamic sectors of the plastics industry in this decade. It is used in numerous applications, such as, outdoor deck floors, railings, fences, landscaping timbers, park benches, window and door frames. This book starts with a brief glimpse at the basic structures and properties of WPCs. Aspects such as surface treatment, machinery used and testing types of WPCs are also covered. The following chapters of the book give a view of foam technology, flame retardant properties and colour retardant properties of WPCs. The way morphology affects or controls the physical and mechanical behaviours of the finished materials is discussed. Finally, the authors give an overview of the applications of wood-plastic composites in daily life. The book may serve as a source book for scientists wishing to work in this field.
Book Synopsis Chemistry of Wood Plastic Composite Weathering by : James Sunday Fabiyi
Download or read book Chemistry of Wood Plastic Composite Weathering written by James Sunday Fabiyi and published by . This book was released on 2007 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid wood has been traditionally used as a decking and siding component in the USA and other parts of the world. However, environmental (because of chemical treatment) and performance (loss of value) issues concerning solid wood in those applications have brought about shift to replace solid wood with WPC. The shift is largely due to the perceived-improved properties, low maintenance, and environmentally benign attributes of WPC. However, a growing issue of concern with these products is their long-term weatherability and color stability. Therefore, retaining WPC color for extended periods during outdoor exposure is of importance. Unfortunately, a fundamental knowledge regarding chemical changes, which influence color changes that occur at the surface of WPC during weathering relative to material compositions are limited. In order to develop WPC with improved weathering performance, the chemical changes of the material compositions that are caused by weathering factors are investigated in this study. The outcomes of such an approach would provide basic understanding of WPC weathering that might likely foster research toward production WPC with improved weathering performance. In this study, the effects of outside and accelerated (UVA and xenon-arc) weathering on the color and chemical changes of wood plastic composites (WPC) produced from different plastics, wood species, and modified wood fiber were investigated. Different analytical techniques were employed to monitor color and chemical changes that occurred during weathering, such colorimetry, Fourier Transform Infrared spectroscopy (STIR), X-ray photoelectron spectroscopy (XPS), Pyrolysis Gas Chromatography - Mass Spectrometry (Py-GC-MS), Gel Permeation Chromatography (GPC), and Differential scanning calorimetry (DSC). The outcomes of weathering trials using high density polyethylene (HDPE), polypropylene (PP) and polyvinyl-chloride (PVC) based WPC with pine wood flour as reinforcement/filler and other additives showed that for both natural and celerated weathering, longer exposure time caused increased color change (and surface lightness), generation of chro ophores, surface oxidation, and wood loss on the weathered WPC surface. Understanding of the basic the and color changes of naturally and accelerated weathered WPC suggest that wood lignin was a contributing factor to WPC color change. Therefore, the outcomes of xenon-arc weathered WPC produced from selected wood species showed that WPC formulation with moderated weathering performance (color stability) could be achieved using wood species of low lignin content (such as poplar). In addition, deligninfied wood fiber based WPC especially from HDPE had less color change compared to untreated wood based WPC. This suggests that cellulose fibers from chemical pulps could be used as a fiber source for weather resistant WPC. In all studies conducted, HDPE-based WPC had the least color change and mostly followed by PP and PVC, which could be associated with thermal history.
Author :Muhammad Abdul Mun'aim Mohd Idrus Publisher :LAP Lambert Academic Publishing ISBN 13 :9783848447619 Total Pages :140 pages Book Rating :4.4/5 (476 download)
Book Synopsis Chemically Modified Tropical Wood Polymer Composite (Twpc) by : Muhammad Abdul Mun'aim Mohd Idrus
Download or read book Chemically Modified Tropical Wood Polymer Composite (Twpc) written by Muhammad Abdul Mun'aim Mohd Idrus and published by LAP Lambert Academic Publishing. This book was released on 2012-03 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical modification is an often-followed method to replace glass fibers with wood fibers to reinforce polymer composites in order to produce biomaterials. However due to the surface incompatibility and weak adhesion between polymer and fiber, many new chemical and binder added were introduced by researchers to improve the mechanical and physical properties of wood polymer composites (WPC). In this study, liquefied tropical wood polymer composites (LTWPC), WPC, treated WPC (TWPC) and binder treated WPC (BTWPC) composite panels were made by using hot-press moulding with varying formulations based on the filler type (LTW, treated sawdust and binder). The effect of LTW, treated sawdust and binder as fillers were investigated. Liquefied tropical wood polymer composites (LTWPCs) were made using liquefied tropical wood (LTW) as a filler and polypropylene (PP) as a matrix.
Book Synopsis Treatments that Enhance Physical Properties of Wood by : Roger M. Rowell
Download or read book Treatments that Enhance Physical Properties of Wood written by Roger M. Rowell and published by . This book was released on 1987 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Wood-Plastic Composites by : Anatole A. Klyosov
Download or read book Wood-Plastic Composites written by Anatole A. Klyosov and published by John Wiley & Sons. This book was released on 2007-08-31 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, practical guide to wood-plastic composites and their properties This is the first book that presents an overview of the main principles underlying the composition of wood-plastic composite (WPC) materials and their performance in the real world. Focusing on the characteristics of WPC materials rather than their manufacture, this guide bridges the gap between laboratory-based research and testing and the properties WPC materials exhibit when they're used in decks, railing systems, fences, and other common applications. Complete with practical examples and case studies, this guide: Describes compositions of WPC materials, including thermoplastics, cellulose fiber, minerals, additives, and their properties Covers mechanical properties, microbial resistance, water absorption, flammability, slip resistance, thermal expansion-contraction, sensitivity to oxidation and solar radiation, and rheological properties of hot melts of WPC Covers subjects that determine esthetics, properties, performance, and durability of wood-plastic composite products Includes comparisons of different ASTM methods and procedures that apply to specific properties This is a comprehensive, hands-on reference for scientists, engineers, and researchers working with wood-plastic composites in plastics and polymers, materials science, microbiology, rheology, plastic technology, and chemical engineering, as well as an outstanding text for graduate students in these disciplines. It's also an excellent resource for suppliers and WPC manufacturers, and an accessible guide for developers, homebuilders, and landscape architects who want to know more about wood-plastic composites and their performance in the real world.
Book Synopsis Wood Plastic Composites Made from Modified Wood by : Kristoffer Segerholm
Download or read book Wood Plastic Composites Made from Modified Wood written by Kristoffer Segerholm and published by . This book was released on 2007 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
