Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2024
Authors
Stephen Amiandamhen Synne Strømmen Ingeborg Olsdatter Ohren Nordraak Andreas Treu Erik LarnøyAbstract
This study investigated the potential of wood particles from Ciol®-treated wood in particleboard production. Ciol® is a renewable formulation from water, citric acid, and sorbitol, which has been commercially developed as a promising alternative for wood modification. Radiata pine wood was impregnated with 60% and 85% concentrations of the Ciol® solution for 150 mins. The impregnated boards were cured and subsequently planned. Particleboards were thereafter produced from the wood shavings using urea formaldehyde (UF) and melamine urea formaldehyde resin (MUF). The boards were produced with or without the use of ammonium nitrate as a hardener. The wood particles and produced boards were characterized via analytical techniques and standard test methods. The effect of Ciol® treatment and its concentration on the properties of the shavings and the particleboards was investigated as well as the effect of the resin type on the panel properties. The use of MUF without the hardener gave the best bending strength of 13 N/mm² and modulus of elasticity of 3187 N/mm². However, there was no significant difference in the results obtained when the hardener was added to MUF resins. Recycling Ciol®-treated wood shavings in particleboard production proved to be a promising approach with MUF resins.
Abstract
Phenol-formaldehyde (PF) resins can be impregnated and cured in situ to improve the woods dimensional stability and decay resistance. In search of renewable alternatives, the substitution of phenol by lignin cleavage products (LCP) has been discussed. However, the different chemical nature may affect the performance of the resin against fungal decay, formaldehyde emission, and equilibrium moisture content. In this study, 30 % (w/w) of the phenol in PF resins were substituted by LCP obtained from microwave-assisted pyrolysis. Scots pine sapwood was modified with the resin. The decay resistance against Rhodonia placenta, Gloeophyllum trabeum, and Trametes versicolor was determined. Additionally, effects of specimen organisation within the Petri dish, different substrates, length of leaching, and type of inoculum were studied. Further, the materials water vapor sorption properties and formaldehyde emission were determined. All modifications effectively reduced fungal decay. With 10 % weight percent gain (WPG), initial decay was detected, while 20 % WPG and 30 % WPG provided efficient protection. The substitution of phenol increases the formaldehyde emission. While further reduction in formaldehyde in the resin admixture or formaldehyde scavengers may be required, the method described herein can be used to partly replace fossil-based phenol, while maintaining good fungal resistance.
Authors
Muhammad Awais Michael Altgen Lone Ross Thomas Kringlebotn Thiis Arnkell Petersen Ingunn BurudAbstract
No abstract has been registered
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No abstract has been registered
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The flammability of cellulosic material restricts its use in insulation and packaging applications. This study examined carbon-based additives to protect cellulose paper against thermal degradation. Carbon nanotubes (CNT) and expandable graphite (EG) were used to modify paper material. Thermal analysis was performed to examine the different modification systems. Our results showed consistently that the addition of EG resulted in an increased fire resistance in the mini fire tube (MFT) test, limited oxygen index (LOI) measurements, and mass loss calorimeter (MLC). In combination with CNT, the heat-release rate could be drastically reduced. Thermal analysis (DSC with TG analysis) revealed that EG had a longer resistance to thermal degradation. The developed composite material can be used, depending on the needs of the industry, as part of thin panel material, partition, or fireproof cladding in construction, railways, transport, automotive, and shipbuilding industries.
Abstract
No abstract has been registered
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The study investigated the feasibility for partial phosphate binder replacement with lignin in phosphate bonded paper sludge composites. A central composite experimental design (CCD) was used to optimise the board manufacturing process, wherein the effect of process temperature, as well as lignin content were investigated with respect to board properties based on the ASTM D1037 standard. Moduli of rupture and elasticity of up to 7.2 MPa and 2.8 GPa respectively in the boards with lignin content of 36–43 wt% and formulation temperatures of 118–133 °C were observed. The phosphate binder input, which bears a huge cost in the process was reduced by up to 49% with lignin incorporation. The effect of pine veneer lamination on the strength properties of the composite boards was investigated. Pine veneer lamination improved mechanical properties, with the moduli of rupture and elasticity increasing from 7.2 to 22.1 MPa (67% increase) and 2.8 to 3.6 GPa (22% increase) respectively. The economic viability of the boards produced was also assessed and the results showed that the required selling price for the composite boards is competitive in the local market for inexpensive construction materials, sold at wholesale prices for between R 158/m2 and R 295/m2, depending on product finishing.
Abstract
Heat treatment increases the decay resistance of wood by decreasing its hygroscopicity, but the wood material remains degradable by fungi. This study investigated the degradation of heat-treated wood by brown rot fungi, with the aim of identifying fungal-induced hygroscopicity changes that facilitate degradation. Scots pine sapwood samples were modified under superheated steam at 200 and 230 °C and then exposed to Coniophora puteana and Rhodonia placenta in a stacked-sample decay test to produce samples in different stages of decay. Sorption isotherms were measured starting in desorption from the undried, decaying state to investigate their hygroscopic properties. Although there were substantial differences in degradative ability between the two fungi, the results revealed that decay by both species increased the hygroscopicity of wood in the decaying state, particularly at high relative humidity. The effect was stronger in the heat-treated samples, which showed a steep increase in moisture content at low decay mass losses. The reference samples showed decreased hygroscopicity in absorption from the dry state, while the heat-treated samples still showed an increase at low mass losses. Near infrared spectroscopy showed that the early stages of decay were characterised by the degradation of hemicellulose and chemical changes to cellulose and lignin, which may explain the increase in hygroscopicity. The results provide a new perspective on brown rot decay and offer insight into the degradation of heat-treated wood.
Authors
Samuel L. Zelinka Samuel V. Glass Eleanor Q. D. Lazarcik Emil E. Thybring Michael Altgen Lauri Rautkari Simon Curling Jinzhen Cao Yujiao Wang Tina Künniger Gustav Nyström Christopher Huber Dreimol Ingo Burgert Mohd Khairun Anwar Uyup Tumirah Khadiran Mark G. Roper Darren P. Broom Matthew Schwarzkopf Arief Yudhanto Mohammad Subah Gilles Lubineau Maria Fredriksson Marcin Strojecki Wiesław Olek Jerzy Majka Nanna Bjerregaard Pedersen Daniel J. Burnett Armando R. Garcia Els Verdonck Frieder Dreisbach Louis Waguespack Jennifer Schott Luis G. Esteban Alberto Garcia-Iruela Thibaut Colinart Romain Rémond Brahim Mazian Patrick Perre Lukas Emmerich Ling LiAbstract
Automated sorption balances are widely used for characterizing the interaction of water vapor with hygroscopic materials. These instruments provide an efficient way to collect sorption isotherm data and kinetic data. A typical method for defining equilibrium after a step change in relative humidity (RH) is using a particular threshold value for the rate of change in mass with time. Recent studies indicate that commonly used threshold values yield substantial errors and that further measurements are needed at extended hold times as a basis to assess the accuracy of abbreviated equilibration criteria. However, the mass measurement accuracy at extended times depends on the operational stability of the instrument. Published data on the stability of automated sorption balances are rare. An interlaboratory study was undertaken to investigate equilibration criteria for automated sorption balances. This paper focuses on the mass, temperature, and RH stability and includes data from 25 laboratories throughout the world. An initial target for instrument mass stability was met on the first attempt in many cases, but several instruments were found to have unexpectedly large instabilities. The sources of these instabilities were investigated and greatly reduced. This paper highlights the importance of verifying operational mass stability of automated sorption balances, gives a method to perform stability checks, and provides guidance on identifying and correcting common sources of mass instability.
Abstract
The purpose of this review is to report on the state-of-the-art on the interaction of moisture with natural materials and fabricated biomimetic functional materials, with an emphasis upon the hygro-responsive behaviour of wood. The primary objective is to examine how water sorption affects dimensional behaviour and how knowledge of this property in natural plant-based (mainly, but not exclusively wood) materials can be used to inform biomimetic design of moisture-responsive materials and devices. The study examines the literature on natural and bio-inspired materials, concentrating upon sorption kinetics, water migration and location of the sorbed water in the materials and their microstructure and mechanical response of the microstructure and how this affects molecular mobility of the sorbate translating to macrostructural changes. Also included within this review, it is an overview of the main experimental techniques which have been used to investigate the interaction of water with these materials at molecular length scales and how modern techniques can resolve the response of these materials at the cell wall level.