Ahmed Koubaa

Université du Québec en Abitibi-Témiscamingue · Forest Research Institute (IRF)

Continuous plant yarn‐reinforced polylactic acid (PLA) composites were produced through in situ 3D printing, focusing on how plant fiber attributes influence the crystallization, mechanical, and rheological properties of the printed composites. The aim of this study was to assess the viability of plant fibers as substitutes for synthetic ones in en...

The kinetic behavior of a polymer material filled with natural and/or functionalized reinforcement can evolve regarding water absorption, crystallization, and thermal degradation (TD) processes. This study investigates the separate and combined influence of microcrystalline cellulose (MCC) and cellulose acetate (CA) on changes in the water absorpti...

This study explores lignin-retaining transparent wood biocomposite production through a lignin-modification process coupled with epoxy resin. The wood’s biopolymer structure, which includes cellulose, hemicellulose, and lignin, is reinforced with the resin through impregnation. This impregnation process involves filling the voids and pores within t...

Purpose of review This review explores the opportunities and challenges associated with using unconventional and underutilized wood sources, such as fast-growing species, logging residues, fire-damaged wood, and post-consumer wood, to manufacture wood-based composite panels (WBCPs), particularly particleboard, medium-density fiberboard (MDF), and o...

Purpose of Review Conventional formaldehyde-based adhesives for wood-based composite panels are subject to significant concerns due to their formaldehyde emissions. Over the past decade, the wood adhesive industry has undergone a considerable transformation that is characterized by a major push in bio-adhesive development. Various bio-based materia...

The development of cellulose-reinforced biomaterials appears to be an attractive approach for the production of sustainable materials with good mechanical properties. Although 3D printing of cellulose-reinforced biomaterials has become popular, there is very little feedback regarding their use in electrical insulation applications. This study aims...

Materials for low-permittivity and electrical insulation applications need to be re-engineered to achieve sustainable development. To address this challenge, the proposed study focused on the dielectric and mechanical optimization of 3D-printed cellulose-based composites for electrical insulation applications. Two different fillers, microcrystallin...

Recycling paper generates large quantities of Deinking Paper Sludge (DPS), which contains high content of organic matter that can be valorized as a soil amendment. The production process can include mechanical action to detach the ink from the fiber or a combined mechanical and chemical process. For optimal DPS valorization, chemical and physical c...

The global issues concerning the pollution of fossil-based plastics open the opportunity for a transition towards bio-based alternatives for the rigid packaging industry. One of the sustainable solutions consists of blending high concentrations of microcrystalline cellulose (MCC) and Cellulose Acetate (CADS=2.45) with a ductile biopolyester-like Po...

This study investigated the influence of fiber loading and maleated polyethylene (MAPE) coupling agent on the structural, thermal, mechanical, morphological properties, and torque rheology of high-density polyethylene (HDPE) reinforced with Posidonia oceanica fiber (POF) composites. HDPE/POF composites, both with and without MAPE, were manufactured...

Renewable dielectric materials have attracted the attention of industries and stakeholders, but such materials possess limited properties. This research focused on studying polylactic acid (PLA)/cellulose acetate (CA) blends produced by 3D printing to facilitate their integration into the electrical insulation field. The dielectric findings showed...

Recycling of paper generates large quantities of paper sludge that is rich in organic matter and can be exploited to counteract organic matter loss in agricultural soils, especially in some geographical areas, such as the Mediterranean. In order for deinking paper sludge (DPS) to be recycled, chemical and physical characterizations are required alo...

Developing novel eco-friendly broad-spectrum visible light photocatalysts for dye removal is one of the urgent problems for water treatment. Here, copper-doped carbon dots (CDs) were reported to be directly fabricated from chromated copper arsenate (CCA) wood waste for the photocatalytic degradation of the methylene blue dye. The properties of the...

The use of natural fibers as reinforcement in composite materials is growing in different industrial sectors, thanks to their excellent physicochemical properties, environmental reasons, health neutrality, and the European Council Directives on the reuse, recycling, and valorization of components and materials. This introductory chapter focus on th...

In this study, researchers aimed to enhance the properties of wood flour/high-density polyethylene (HDPE) biocomposites by incorporating polycarbonate (PC). To improve the thermal stability of wood flour, boric acid treatment was employed. The treated wood flour was then blended with PC and HDPE to create hybrid polymer biocomposites. The resulting...

Polycyclic Aromatic Hydrocarbons (PAHs) are contaminants that are widespread in water, air, and soil and pose a threat to the environment and humans. This study focuses on the biodegradation of the sixteen priority PAHs listed by the United States Environmental Protection Agency (US-EPA) present in industrial soil using biochar as a growth medium f...

On the Cover This work provides an approach to producing nitrogen-doped (N-doped) carbon materials as gas filters for the removal of SO2 emitted by forestry and mining industries. The figure also shows the feedstock based on reconstituted wood panels that were converted into porous carbon materials through thermochemical conversion processes (fast...

Three-dimensional printing is a prototyping technique that is widely used in various fields, such as the electrical sector, to produce specific dielectric objects. Our study explores the mechanical and dielectric behavior of polylactic acid (PLA) and plasticized cellulose acetate (CA) blends manufactured via Fused Filament Fabrication (FFF). A prel...

The optimization of the machining parameters of strander-canting is the best way to obtain the optimum strand size, a better quality of the cant surface, and lower energy consumption. The effect of the rake angle on the performance of a strander-canter when processing jack pine logs was evaluated. Thirty-nine logs were cut with three rake angles (5...

Table of Contents, Issue 11, Volume 11, Journal of Renewable Materials

The influence of microcrystalline cellulose (MCC) and cellulose acetate (CADS=2.45) on the evolution of crystallization kinetic and thermal degradation of PBS-based materials is addressed in this study. Binary (PBS/CA, PBS/MCC) and ternary hybrid (PBS/CA/MCC) materials were produced through extrusion and mold injection of MCC (30 wt.%), CA (20 wt.%...

Purpose of Review Wood-based adsorbents are increasingly used for environmental applications. They demonstrate considerable advantages, including renewable feedstock, relatively simple preparation processes, and advantageous structural and surface properties. In short, they provide environmentally friendly, effective, and economical sources for con...

Microcrystalline cellulose (MCC–30 wt.%) was extruded with a blend of polybutylene succinate (PBS) and cellulose acetate (CADS=2.5–20 wt.%) to produce two grades of binary (PBS/CA, PBS/MCC) and ternary (PBS/CA/MCC) specimens by injection into a mould previously thermostated at 22°C and 78°C. The structure-property relationships of neat PBS (n-PBS)...

The effects of wood species on the performance of the strander-canting process were studied. Logs of balsam fir (Abies balsamea (L.) Mill.), black spruce (Picea mariana (Mill.) B.S.P.), and jack pine (Pinus banksiana Lamb) were processed under two temperature conditions (-13.3 °C and 22.3 °C). The cutting and feed speeds, rake angle, cutting width,...

Reconstituted wood panels have several advantages in terms of ease of manufacturing, but their shorter life span results in a huge amount of reconstituted wood panels being discarded in sorting centers yearly. Currently, the most common approach for dealing with this waste is incineration. In this study, reconstituted wood panels were converted int...

Bioremediation is an effective way to remove heavy metals from pollutants. This study investigated the effects of Yarrowia lipolytica (Y. lipolytica) on the bioremediation of chromated copper arsenate (CCA)-treated wood wastes. Copper ions stressed the yeast strains to improve their bioremediation efficiency. A comparison of changes in morphology,...

The relative proportions of different chemical components in wood tissues is one of the underlying factors that control wood properties. These proportions vary within and between woody tissues, and an accurate description of these variations is critical for parameterizing forest biogeochemical budgets and models. White spruce (Picea glauca (Moench)...

An ecofriendly approach was developed for preparing copper-doped carbon dots (CDs) with superior photocatalysis using chromium-copper-arsenic (CCA)-treated wood waste as a precursor. Original wood (W-CDs), CCA-treated wood (C-CDs), and bioremediation CCA wood (Y-CDs) were used as the precursors. The chemical composition and structural, morphologica...

Thuja occidentalis L. wood is desirabl, e for wooden structures that require wood density uniformity. Wood density is a wood quality indicator related to numerous morphological, mechanical, physiological, and ecological properties. This study aimed to investigate the regional, site, and tree-to-tree variations of T. occidentalis wood density and gr...

Four Picea glauca (Moench) Voss trees grown at each of four square spacing intensities between trees: 1.2 m, 1.8 m, 4.3 m, and 6.1 m in a plantation established in 1967 in the Petawawa Research Forest, Ontario, Canada (lat. 45.59 N, long. 77.25 W, elev. 168 m) and sampled at four different heights (1.3 m, 4.3 m, 7.3 m, 10.3 m) were used to study th...

The internal structure of oriented strand board (OSB) is made of a large number of voids. This results from the complexity of strand distribution within the panel and impacts panel performance greatly. In this research, X-ray microcomputer tomography was used to investigate the void characteristics of OSB panels with different structures. The resul...

Purpose of review Transparent wood (TW) has attracted much interest from researchers as an emerging optical load-bearing material because of its advanced characteristics. These advantages mainly include being renewable, existing abundant reserves, low cost, interesting optical properties, outstanding mechanical performance, and low thermal conducti...

Chromated copper arsenate-treated (cca) wood disposal faces environmental restrictions due to its toxicity, heavy metal leaching in storage sites, and greenhouse gas emissions during incineration. Thus, finding new management methods for this contaminated wood at the end of life is crucial. This study evaluated the effect of pyrolysis temperature (...

The flame retardancy of wood–polymer composites significantly affects their potential applications. Thus, multilayered wood flour/high-density polyethylene (HDPE)/polycarbonate (PC) composites were prepared via thermocompression to improve the fire retardancy of wood–polymer composites in this paper. Thermal degradation behavior, flame retardancy,...

Incorporating biodegradable reinforcement, such as wood particles, into rigid polyurethane foams (RPUFs) is among the alternatives to reduce their environmental impact. This study aims to assess the effect of different wood particles as reinforcement in RPUFs. Reinforced rigid polyurethane foams are synthesized with milled wood particles of various...

Black spruce is widely used for lumber production in Eastern Canada, and it has the potential to replace trembling aspen and paper birch for oriented strand board (OSB) manufacturing. This study evaluated the bending modulus of elasticity (MOE) and modulus of rupture (MOR), the internal bond (IB), and the thickness swelling (TS) of OSB panels made...

We investigated the effects of polymer blend variation on the physical, mechanical, and thermal properties of wood-polymer composites (WPC). We used high-density polyethylene (HDPE) and polypropylene (PP) and a combination of 80% PP, 20% HDPE, and 80% HDPE, 20% PP as polymer blends for WPC formulations to simulate recycled plastics. We used black s...

This study aims to investigate the feasibility of producing OSB from softwood species used in the Eastern Canadian softwood lumber industry in the context of the overcapacity of softwood chips traditionally produced for the pulp and paper industry. Balsam fir, black spruce, and jack pine logs were used to make 15 mm thick OSB panels with a target d...

Effects of counter-knife and wood temperature were studied relative to the size distribution of Jack pine strands processed by a strander-canter. Studied factors included the counter-knife angle (60°, 75°, 90°, and 105°) and the distance between the edges of the counter-knife and knife (6 mm, 11 mm, and 16 mm). The nominal cutting speed was fixed a...

The global cannabis (Cannabis sativa) market was 17.7 billion in 2019 and is expected to reach up to 40.6 billion by 2024. Canada is the 2nd nation to legalize cannabis with a massive sale of $246.9 million in the year 2021. Waste cannabis biomass is managed using disposal strategies (i.e., incineration, aerobic/anaerobic digestion, composting, and...

The accuracy and precision with which carbon amounts have been accounted for in forests have been questioned. As countries seek to comply with agreements to reduce global warming and industries seek to maximize bioenergy potential, this matter has increased international concern. White spruce (Picea glauca (Moench) Voss) stand density management tr...

Energy storage is currently one of the most significant technological challenges globally, and supercapacitor is a prominent candidate over batteries due to its ability for fast charging and long lifetime. Supercapacitors typically use porous carbon as electrodes, because of both the high conductivity and surface area of the material. However, the...

Presentation of my PhD project to the annual meetings of the International Research Network (IRN) and the International Research Laboratory (IRL) on Cold Forests, as an active member of these research groups.

The project aims to develop cellulose in new biocomposites to produce dielectric materials based on thermoplastic matrices. Cellulose fibers bring multiple advantages to thermoplastic matrices in mechanical, physicochemical, thermal, and dielectric properties. Although these biocomposites are known for their advanced mechanical properties, only a f...

Thermal treatments such as torrefaction and fast pyrolysis are commonly employed methods to produce biofuels with high-energetic properties. In this study, wood chips were heat-treated at different temperatures of torrefaction (315 °C) and fast pyrolysis (400 and 454 °C) to form energetic pellets. Three softwoods, jack pine (JP), balsam fir (BF), a...

Fire risk limits further commercial utilization of bio-based composites. In this study, polycarbonate (PC) hybridization improved the fire retardancy and the mechanical properties of wood flour/high-density polyethylene (HDPE) bio-based composites. A boric acid treatment improved the thermal stability of wood flour; the latter was then combined wit...

The moisture sensitivity of wood–polymer composites (WPCs) is mainly related to their hydrophilic wood components. Coatings are among the alternatives that improve the dimensional stability of these composites. However, the adhesion of most coatings to the WPC surface is generally poor. Thus, chemical and/or mechanical treatments should be applied...

Demand for high-performance biocomposites is increasing due to their ease of processing, low environmental impact, and in-service performance. This study investigated the effect of boric acid modification of wood flour on polycarbonate (PC) wood composites’ thermal stability, fire retardancy, water absorption, and creep behavior. The composites’ fi...

Abstract Alkaline organic residues, such as wood ash (WA), deinking paper sludge (DPS), and mixed paper sludge (MPS) could have a significant potential for mitigating greenhouse gases (GHG) when they are used for land application. The DPS was mixed and then granulated with MPS, WA and/or composted DPS to form pellets. A 56-d incubation study was ca...

Wood polymer composites (WPC) are sensitive to moisture because of the hydrophilic nature of the wood fibers. The main objective of this study was to improve the dimensional stability of WPCs by coating. Polypropylene and polylactic acid were reinforced by three pulp fibers (kraft, thermomechanical (TMP), and chemothermomechanical (CTMP)) at three...

The characterization of the dielectric properties of wood–polymer composites (WPCs) is essential to understand their interaction with electromagnetic fields and evaluate their potential use for new applications. Thus, dielectric spectroscopy monitored the evolution of the dielectric properties of WPCs over a wide frequency range of 1 MHz to 1 GHz....

Radar Absorbing Materials (RAMs) are composite materials able to attenuate an incident electromagnetic wave. Usually, RAMs are made of a polymeric matrix and an electromagnetic absorbent filler, such as silicon carbide or carbon black. Several materials have been investigated as potential fillers, aiming to improve the Reflection Loss (RL) and abso...

This study evaluated the effects of de-inking paper sludge (DPS) and sewage sludge (SS) application on soil properties, and durum wheat growth and yield. A pot experiment was performed on Calcaric cambisol (clCM) and Cromic Luvisol (coLV) soils. Three DPS rates (0, 30, and 60 Mg ha−1) were studied with and without nitrogen fertilizer (280 kg NH4NO3...

Static bending tests to measure modulus of elasticity (MOEST) or wood stiffness provide an indicator of the structural performance of a finished product. These tests are however, slow and expensive. Tests to measure MOE using non-destructive testing (NDT) provide alternatives to MOEST tests; however, relationships between the different modes of mea...

A recent trend in ecofriendly product development is the use of added-value lignin residues. This study aimed to assess the potential use of pyrolytic lignin (PL) for producing rigid polyurethane foam (RPUF). For this purpose, PL was recovered from bio-oil using water as extraction solvent. The PL was then subjected to oxypropylation in the presenc...

Biochar is a carbon-rich organic material that has advantageous physicochemical properties for applications in multidisciplinary areas of science and engineering, including soil amendment, carbon sequestration, bioenergy production, and site rehabilitation. However, the typically low porosity and surface area of biochars (from 0.1 to 500 m² g⁻¹) li...

The surplus of wood chips from sawmills is increasing due to the reduction in the demand for newsprint paper. Thus, this study aims to promote the use of wood chips for bioenergy by producing high-quality pellets. More specifically, this project aimed to evaluate the impact of various heat treatment approaches on the heating value of wood pellets m...

The use of deinking paper sludge (DPS) as a fertilizer instead of sending it to landfill could play a role in reducing greenhouse gases and improving soil properties. The objectives of this study were (1) to evaluate the changes in the physical (permeability and structural stability), chemical (particularly soil pH), and biological (microbial metab...