Saïd Elkoun

• Université de Sherbrooke

This study explores the development of conductive co-continuous polyvinylidene fluoride/polypropylene/graphite (PVDF/PP/GR) composites with varying PVDF/PP ratios (60:40 and 70:30) to evaluate the effects of single and hybrid GR fillers on composites’ electrical conductivity, morphology, thermal stability, and mechanical properties. The composites...

This study investigates the impact of graphite (GR) concentration and particle size on the performance of conductive polymer composites (CPCs) using polyvinylidene fluoride (PVDF), polypropylene (PP), and polyethylene terephthalate (PET) as matrix materials. Composites were prepared with GR concentrations ranging from 20 to 60 wt. % and particle si...

The increasing demand for sustainable materials in automotive applications, coupled with the critical need to address marine plastic pollution, presents an opportunity for innovative material development. This study explores composites made from recycled polyamide 6 (PA6) fishing nets reinforced with switchgrass fibers (0–30 wt%). The composite wit...

This work describes the thermal aging behavior of three industrial elastomeric compounds based on styrene–butadiene rubber (SBR) reinforced with carbon black. Samples were exposed to thermo‐oxidative aging at temperatures ranging from 70 to 120°C for durations between 14 and 365 days. The tensile and hardness tests were performed on the samples to...

Pretreatment of lignocellulosic biomass remains the primary obstacle to the profitable use of this type of biomass in biorefineries. The challenge lies in the recalcitrance of the lignin-carbohydrate complex to pretreatment, especially the difficulty in removing the lignin to access the carbohydrates (cellulose and hemicellulose). This study had tw...

This study explores the development of electrically conductive co-continuous polyvinylidene fluoride/polyethylene terephthalate (PVDF/PET) nanocomposites incorporating graphite (GR) and reduced graphene oxide (rGO) for potential use in proton exchange membrane fuel cell (PEMFC) bipolar plates. The influence of GR particle size, concentration (20–60...

The article explores the development of sustainable composites for automotive applications using recycled polyamide 6 (PA6) derived from discarded fishing nets, reinforced with switchgrass fibers (0–30 wt%). The study investigates the mechanical, thermal, and processing properties of these composites, finding that 30 wt% switchgrass fibers signific...

Milkweed (MW) fiber is a natural fiber that provides tremendous thermal insulation properties due to its lightweight hollow structure. This study aimed to investigate the effect of milkweed fiber as a thermal fiber in nonwovens. Milkweed fibers were blended with a low-melt fiber consisting of a polyethylene terephthalate core, a polyolefin sheath (...

Fibers from milkweed, which grows in Quebec (Canada), offer a distinct and outstanding advantage compared to other natural fibers: their ultra-lightweight hollow structure provides excellent acoustic and thermal insulation properties for the automobile industry. To highlight the properties of milkweed fibers and reduce the use of synthetic material...

A semi-empirical model for the assessment and an optimization procedure of the sound absorption coefficient of compressed nonwoven fibrous materials made from recycled Nylon fibers (RNF) is developed. In general, the prediction of the sound absorption properties of materials requires the measurement of non-acoustic parameters by specialized charact...

Phanerochaete chrysosporium is considered the model fungus for white rot fungi. It is the first basidiomycete whose genome has been completely sequenced. Its importance lies in the fact that its enzymatic system comprises the major enzymes involved in lignin degradation. Lignin is a complex and highly recalcitrant compound that very few living orga...

Eco-friendly wall cladding panels were developed from fishing industry waste by incorporating discarded ropes, wood fibers from lobster cages, and clamshell powder. Four panel formulations were investigated using MAPP and MAPE coupling agents: FRW-M (97% fishing rope), 30WF-M (67% rope with 30% wood fibers), 30CS-M (67% rope with 30% clamshell powd...

Fused deposition modeling (FDM), an economical additive manufacturing (AM) technique, is widely used for extruding thermoplastic filaments. Acrylonitrile butadiene styrene (ABS) is a widely used polymer for FDM technique due to its inexpensive cost, strong impact strength, great durability, and intriguing uses. ABS materials are used for interior p...

This study uses an extrusion process to formulate blends based on recycled high-density and high-molecular-weight polyethylene (recHDPE, recHMWPE) for the manufacture of rainwater drainage pipes. The main objective of this project is to investigate the effects of incorporating graphene on the mechanical, thermal, and stress-cracking resistance prop...

This study investigates the potential for recycling fishing rope waste from the Magdalen Islands, Canada, into sustainable wall cladding panels, addressing both environmental concerns and waste management challenges. A comprehensive characterization of the fishing ropes was conducted using various analytical techniques to assess their suitability f...

Fused deposition modeling (FDM), an economical additive manufacturing (AM) technique, is widely used for extruding thermoplastic filaments. Acrylonitrile butadiene styrene (ABS) is a widely used polymer for FDM technique due to its inexpensive cost, strong impact strength, great durability, and intriguing uses. ABS materials are used for interior p...

Additives, such as antioxidants (AOs), carbon black (CB) and compatibilizers (COs), are used in recycled polymer blends for different reasons. AOs slow thermal degradation, CB gives blends a black color and protect them against ultraviolet (UV) light, and compatibilizers improve compatibility between the different phases of the mixture and conseque...

Polyetherimide (PEI) possesses remarkable mechanical and thermal properties that make it a promising high-performance material for a wide range of applications. In addition to its simple processability, adhesive properties, and minimal smoke emission when heated, PEI is a suitable material for additive manufacturing. Because of its low cost and str...

This study concerns the optimization of an industrial recycling line; in other terms, this paper aims to find the optimal processing parameters that allow for a decrease in the loss of stress crack resistance (SCR) using a notched crack ligament stress (NCLS) test and an increase in the gain of the elongation at break, flexural modulus, and Izod im...

Additive manufacturing (AM) has been widely used for rapid prototyping (RP) techniques due to its low cost and customizability. This technique allows for rapid and competitive price production compared to conventional manufacturing. However, pieces fabricated with the AM technique usually possess poor mechanical and surface properties compared to t...

Lignocellulosic biomasses, mainly forestry and agricultural residues, are inexpensive, available and attractive to reduce the dependence of the world on fossil fuels. However, before their processing in biorefineries, they must undergo a pre-treatment to allow access to the desired compounds of interest (cellulose, hemicellulose, or lignin). Howeve...

This research centered on enhancing the mechanical properties of sustainable composite materials made from short flax fibers. Challenges associated with fiber–matrix adhesion and moisture absorption were systematically addressed. A water–alginate pre-treatment, combined with plasma modification, was employed to stabilize the fibers, ensuring their...

Significant progress has been made in recent years in the use of atmospheric pressure plasma techniques for surface modification. This research focused on the beneficial effects of these processes on natural by-products, specifically those involving natural fiber-based materials. The study explored the deposition of hydrophobic organosilicon-like t...

This study investigated the influence of fiber content, temperature, and relative humidity on the thermal insulation properties of nonwoven mats made of seed fibers from Asclepias Syriaca, commonly known as milkweed floss. Nonwoven mats with a 1-inch thickness were produced by uniformly arranging milkweed fibers within a mold. Various quantities of...

It is my pleasure to announce that our recently published article "Microwave-Assisted Chemical Purification and Ultrasonication for Extraction of Nano-Fibrillated Cellulose from Potato Peel Waste" was chosen for the "front page" of the current Issue (4) of MDPI "Macromol", Volume 3. Thanks to MDPI for the opportunity and a big thank to all the peop...

Nanofibrillated cellulose was extracted from potato peel waste using a fast and green method with a simple process. To extract cellulose and eliminate non-cellulosic constituents, alkaline and hydrogen peroxide treatments were performed under microwave irradiation. The nanofibrillated cellulose was extracted from purified cellulose via TEMPO oxidat...

During the last decade, the consumption of plastics has increased highly in parallel with plastic waste. The transition towards a circular economy is the only way to prevent the environment from landfilling and incineration. This review details the recycling techniques with a focus on mechanical recycling of polymers, which is the most known and de...

In recent years, there has been a growing attempt to manipulate various properties of biodegradable materials to use them as alternatives to their synthetic plastic counterparts. Alginate is a polysaccharide extracted from seaweed or soil bacteria that is considered one of the most promising materials for numerous applications. However, alginate po...

In recent years, fused deposition modeling (FDM) (or 3D printing) technology is increasingly applied in the automotive industry due to its rapid operation and cheap costs. The use of high-performance polymers which can retain their good properties under high temperatures and harsh conditions, along with 3D printing techniques is, therefore, essenti...

Flax fibers have found widespread use in eco-composite materials because of their remarkable mechanical properties compared to glass fibers. However, their low stability limits their use on a larger scale when employed in hot or humid environments. Therefore, the surfaces should be modified before the composite process to provide the best interfaci...

The present paper deals with a comprehensive experimental study of the hysteresis phenomenon of alumina-water based nanofluids taking place during heating-cooling cycles. The emphasis was particularly put on the relationship between this phenomenon and the dispersion state of alumina nanoparticles. Thus, by carrying out simultaneous thermal conduct...

The use of natural fibers is a sustainable alternative for developing reinforced-polymer composites. It is believed that the seed flosses of common milkweed, Asclepias Syriraca, may be a promising reinforcing fiber given its uncommon hollow microstructure that is associated with both high specific properties and outstanding insulating capacities. T...

Milkweed floss was used as a reinforcement to develop lightweight epoxy composites with enhanced thermal insulating properties. Seed fibers from Asclepias Syriaca harvested in Quebec were used for this study. Some fibers were treated with acetone to remove their protective hydrophobic coating. Epoxy resin was blended with 15% w/w of native or aceto...

Development of a new biomass pretreatment approach

Polylactic acid (PLA) has shown two different crystalline structures, namely α and α′ when cooled down from the melt state. However, α-PLA has shown significant improvement in the barrier and mechanical properties of PLA. Although the effect of some nucleating agents on phase transformation of the PLA has been determined in the past, this is the fi...

Polyhydroxyalkanoates (PHAs) have emerged as an alternative to petrochemical-based plastics in recent decades. They are biodegradable linear polyesters that are mainly produced from microorganisms. They are also biocompatible and non-toxic, making them great candidates in medical and pharmaceutical applications such as drug delivery. The PHA family...

The present work seeks to determine the impact of weight percentage (wt%) of grafted starch nanocrystals (g-SNCs) on the oxygen and water vapour permeability of poly (lactic acid), PLA. Changes in the oxygen and water vapour permeability of PLA due to changes in PLA’s crystalline structures and lamellar thickness were quantified. To this end, 3, 5,...

In this work, the effect of lactic acid grafted starch nanocrystals (g-SNCs) on the rate of the soil burial degradation of Poly (lactic acid) was studied using the weight loss measurement (wt.%), X-ray Photo Electron Spectroscopy (XPS), Fourier-Transform Infrared Spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC). The weight loss resu...

This research aimed to evaluate the improvement of the mechanical properties of composites and their reduction of weight induced by milkweed floss (MW). As MW is severely affected by surface treatments, a good inherent affinity with the matrix is required for efficient reinforcement. Thus, composites made of MW and polyamide (PA11) (or polypropylen...

Polypyrrole (PPy) is the most widely investigated electrically conductive biomaterial. However, because of its intrinsic rigidity, PPy has only been used either in the form of a composite or a thin coating. This work presents a pure and soft PPy membrane that is synergically reinforced with the electrospun polyurethane (PU) and poly-l-lactic acid (...

In this study, unidirectional flax fabrics were used to reinforce poly(lactic acid) (PLA). Flax/PLA composites were produced by thermo-compression using as-received flax fibers and titanium dioxide (TiO2) coated flax fibers. The aim was to investigate the effect of annealing temperature and time, under quiescent or mechanical stress conditions, on...

This work aimed at investigating the feasibility of surface modification of cellulose nanocrystals (CNCs) using in situ ring opening polymerization of ε-caprolactone (ε-CL) at room temperature. Residues of flax and milkweed (Asclepias syriaca) stem fibers were used as a source of cellulose to obtain and isolate CNCs. The cationic ring opening polym...

Cellulose nanocrystals or nanoparticles (CNCs) have drawn a lot of attention due to their abundance, biocompatibility, renewability and their excellent mechanical properties paving the way to innovative and sustainable applications. In the present work, the stem residues of Asclepias syriaca L., better known as milkweed and generally regarded as a...

Fiber treatments to enhance interfacial adhesion in natural fiber-reinforced composites generally induce the use of many chemicals. To address this issue, the present work aimed to develop innovative and ecological fiber treatments to produce 100%-green composites, by investigating interfacial adhesion between modified flax fibers and polylactic ac...

This study aims at measuring the interfacial properties of natural fibers in polypropylene composites by the mean of direct methods of characterization. Bamboo lamellae (BL) and polypropylene (PP) were used to produce laminated composites with continuous and homogenous interfaces. This research also focuses on the effect of maleic anhydride-grafted...

This study aimed at investigating the reinforcement effect of milkweed (MW) floss, a smooth and homogeneous natural fiber with a wide hollow lumen, on bio‐based polymer composites. First, MW floss was thoroughly characterized in terms of morphology, surface roughness, and tensile and thermal resistance. Then, MW floss was compared to flax fibers, o...

Lignocellulosic nanofibres (LCNF) are nanometer additives that can be used to improve the mechanical, esthetical, optical and thermal properties of polymers in composites, packages, or coatings. Surface modification of these hydrophilic nanometer additives is needed to improve their properties and applicability in hydrophobic polymers matrix. In th...

The aim of this study was to enhance the mechanical properties of milkweed floss (MW)/polylactic acid (PLA) composites by compatibilizing the interface between MW and PLA. MW floss is a natural fiber exhibiting a wide lumen and a thin cross-section. The addition of high specific surface area MW fibers to polymer matrices can lead to significant imp...

Flax fibres are an agro‐industrial waste available in large quantities in several countries around the world. This resource can be properly used. The goal of this work was to extract lignocellulosic nanosized flax fibres using an environmentally friendly process based on a combination of supercritical carbon dioxide (SC‐CO2) pre‐treatment and enzym...

In this work, starch nanocrystals were chemically grafted with lactic acid using esterification reaction and its compatibility with poly (lactic acid) (PLA). Initially, ungrafted and grafted starch nanocrystals were characterized to understand the crystalline, functional, thermal and morphological properties by means of wide-angle X-ray scattering,...

This study aims to evaluate the potential of milkweed as potential candidate to construct biodegradable scaffold for bone regeneration. A mat made of milkweed, polyethylene, and polypropylene was treated with an atmospheric pressure plasma to functionalize the surface of the polymer assembly with carboxylic acid groups, which enable to conjugate bi...

Natural fibers have been approved as an excellent alternative for traditional reinforcements in polymer composites. However, the main disadvantage of natural fibers as reinforcements is their poor interaction with polymeric matrices due to their hydrophilic nature. In order to improve their compatibility as composite reinforcement, surface treatmen...

This work investigates the validity of recent micro-macro solid fibre relationships for the case of a nonwoven fibre structure made from milkweed floss, a natural hollow fibre. The hypothesis that hollowness of the fibre has only small effects on the acoustics of the material is verified. This is done to ensure that the use of a single porosity mod...

The growing concern over the environment raises the question of biodegradability and renewability in numerous fields, including materials and energy. Therefore, industries and researchers focus more on the development of biomaterials generated from natural sources. In this context, proteins and their unique properties made them ideal candidates to...

Asclepias syriaca L., has been recently grown in Quebec, Canada, for commercial applications. Because of lack of information on the chemical composition of this fiber, a study has been conducted to isolate the components using three different procedures of extraction. Then, these components have been analyzed by different techniques, including FTIR...

The present work proposes a detailed experimental analysis of the dispersion regimes within nanofluids. For this purpose, simultaneous measurements of thermal conductivity and dynamic viscosity are performed for alumina / water-based nanofluids at volumetric concentrations Phi ranging from 0.2 to 2%. Depending on the pH values, five dispersion regi...

The nano sized cellulose materials is topical in the sphere of sustainable materials lately. The two key groups of nanocellulose (NC) are 1) Nanofibrillated cellulose (NFC) and 2) Cellulose nanocrystals (CNC). They are often considered as a second-generation renewable resource, which also serves as a better replacement for the petroleum-based produ...

Compression molding is a current technique in polymer processing. Despite numerous studies, effect of molding pressure on physical properties has surprisingly not been fully investigated. In this study, the thermal and mechanical behavior of the compression-molded polyethylene were thus explored to better grasp the relationship between processing p...

Agriculture biomass is an alternative possible solution for the extraction of cellulose, compared to the classical soft and hard wood. However, the valorization of cellulose is challenging for the researchers as it involves multiple steps. In the present study, the raw fibers of flax, hemp and milk weed stem fibers werepurified in single step using...

PLA is well known to exhibit a low degree of crystallinity and slow crystallization kinetics. It is also a polymorphic material with two slightly different crystalline phases named α and α’. This work aimed at investigating the effect of PLA crystalline phases on the kinetics of crystallization, by means of a simple, telling and expedient technique...

The main drawbacks of flax fibers have been attributed to poor compatibility with polymer matrices as well as relatively high water absorption. The aforementioned properties are mainly due to the presence of hydrophilic hydroxyl functional groups on the backbone of the flax fibers. This study aims to convert primary alcoholic (OH) groups on the sur...

Abstract In this study, cellulose-II nanospheres (CNS) were extracted from flax fibers and analyzed to understand the crystalline, functional and morphological properties by means of X-ray Diffraction (X-RD), Fourier Transform Infrared (FT-IR) and Scanning Electron Microscopy (SEM). FT-IR and SEM results indicate the effective removal of extractive...

This research is intended to improve the interface between the fibers and the matrix and limit water absorption of bio-based material thereby decreasing degradation of the composites when they are exposed to external environment such as high temperature and humidity. In this study, flax fibers were treated with an organic surface coating containing...

In this paper, dynamic viscosity, surface tension, density, heat capacity and thermal conductivity, of a bronchial mucus simulant proposed by Zahm et al. [1991] were experiementally determined. This simulant is mainly composed of a galactomannan gum and a scleroglucan. It was shown that thermophysical properties of synthetic mucus are dependant of...

In this work, we showed how the functionalization of multiwall carbon nanotubes (MWCNT) by nitric acid (HNO3) and their predispersion into poly (butylene terephthalate) (PBT) improved the through-plane electrical conductivity and mechanical properties of co-continuous morphology polyvinylidene fluoride (PVDF)/poly (ethylene terephthalate) (PET)/car...

A poroelastic characterization of open-cell porous materials using an impedance tube is proposed in this paper. Commonly, porous materials are modeled using Biot’s theory. However, this theory requires several parameters which can be difficult to obtain by different methods (direct, indirect or inverse measurements). The proposed method retrieves a...

Natural solid fibers such as flax, hemp or kenaf are usually mixed with polymeric matrices in order to produce fiber-reinforced polymers (FRP) [1]. Thanks to the relative low density of natural fibers, these composites are more weight effective compared to traditional glass reinforced composites. The need of weight saving has led the automotive ind...

In this study, flax fibers were oxidized in order to improve the interfacial adhesion of cellulosic fibrils to a TiO2 coating. The TiO2 coating was created on the flax fiber by a Sol–Gel dip-coating technique. The effect of cellulose oxidation and the consequent TiO2 grafting was studied on cellulose crystalline structures using X-ray diffraction....

Effect of weak and strong shear flow on the crystallization of poly(lactic acid), PLA, with different molecular weights, (Mw), was investigated by rheological measurements. To study the effect of the weak flow, PLA samples were heated up to 190 °C to erase thermal history, then rapidly cooled down to 130 °C and finally subjected to a shear flow wit...

The present work focuses on the preparation and the stabilization of Al2O3-water based nanofluids. Though they have been widely considered in the past, to the best of our knowledge, there is no clear consensus about a proper way to prepare and stabilize them by the appropriate surfactant. In this paper, a careful experimental investigation is perfo...

The present work focuses on the preparation and the stabilization of Al2O3-water based nanofluids. Though they have been widely considered in the past, to the best of our knowledge, there is no clear consensus about a proper way to prepare and stabilize them by the appropriate surfactant. In this paper, a careful experimental investigation is perfo...