Oxydation tempo des fibres lignocellulosiques: une nouvelle approche pour le traitement silanique efficace (original) (raw)
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The Effects of Chemical Treatments of Flax Fiber on Some Engineering Properties of Biocomposite
2006 CSBE/SCGAB, Edmonton, AB Canada, July 16-19, 2006, 2006
Flax fiber, produced through a conventional scotching mill, was washed using a commercial detergent and then it was chemically treated using silane, benzoyle and peroxide. The chemically treated fibers were dried by an air-cabinet drier at 70 °C. The dried fiber were ground and truly mixed with HDPE at a ratio of 10% flax fiber and 90% HDPE. After extruding and pelleting, the mixture was fed through a rotational molding machine and composite plates were produced. The resulting composites were tested for their various mechanical properties using standard ASTM procedures. The test results indicated that the mechanical strength of the composites was higher than the plates made from HDPE, however there was no significant difference between the mechanical strength of composites produced from various chemical treatments. The optical properties of the composites were investigated using NIR spectroscopy. The % of reflectance of the NIR at a wide range of wavelength indicated that HDPE plates were easily distinguishable, however the chemically treated composites and untreated composites were not distinguishable from each other using this technique. Papers presented before CSBE/SCGAB meetings are considered the property of the Society. In general, the Society reserves the right of first publication of such papers, in complete form; however, CSBE/SCGAB has no objections to publication, in condensed form, with credit to the Society and the author, in other publications prior to use in Society publications. Permission to publish a paper in full may be requested from the CSBE/SCGAB Secretary,
Biomechanism and Bioenergy Research, 2022
Measurement of mechanical properties of biocomposites is a good method for evaluating their effectiveness of adhesion between fiber and polymer matrix. In this research, the effects of four different chemical treatments of flax fiber on some mechanical properties of their biocomposites was investigated. Initially, the flax fiber was soaked in alkaline, silane, benzoyle and peroxide solution and the fiber were dried in an air-cabinet drier at 70°C. After grinding, each group were separately mixed with HDPE powder at a ratio of 10% flax fiber and 90% HDPE. From these mixture, composite plates were prepared through extruding, pelleting, and rotational molding. The resulting composites were tested for their various mechanical properties using tensile tests. The test results indicated the maximum strain was 6.22%, maximum supported load at yield point was 582 N, maximum stress at yield pint was 20.26 MPa and maximum modulus of elasticity was 467.75 MPa all for alkaline treatment. It was found that all tested mechanical properties for HDPE were significantly lower than the composites made from fiber containing biocomposites. However there was no significant difference between the mechanical strength of composites produced from various chemical treatments.
Science and Engineering of Composite Materials, 2008
Flax fibers can be used as ecological alternatives to conventional reinforcing fibers (e.g., glass) in composites. Flax fibers have some advantages over glass fiber, because they are less dense, renewable, combustible and are relatively low in price. This excellent price-performance ratio at low weight, in combination with the environmentally friendly character is very important for the acceptance of natural fibers in large volume engineering markets. A major restriction to the successful use of natural fibers in durable composite applications is their high moisture absorption and poor dimensional stability. In order to improve the above qualities, various surface treatments of fibers including silane treatment, benzoylation, and peroxide treatment were carried out, to improve mechanical performance of fiber composites. Also, composites consisting of high-density polyethylene (HDPE) or linear low-density polyethylene (LLDPE) or HDPE/LLDPE, chemically treated fibers and additives were prepared by extrusion process. The extruded samples were then ground and test samples were prepared by rotational molding. The chemical analysis showed that selective chemical treatments increased the α-cellulose content of flax fibers from 73% to 95%, but caused a decline in hemicellulose and lignin content. Derivative thermogravimetry (DTG) curves indicated that chemically treated fibers were thermally stable in the region below 250 °C and chemcial treatments increased the onset thermal decomposition temperature of flax fibers. The mechanical properties demonstrated an increase in tensile strength from 17.56 MPa of untreated fiber (20 wt%) reinforced LLDPE to 25.86 MPa of peroxide treated fiber (20 wt%) reinforced LLDPE. The increased hardness of flax fiber-reinforced composites was also very promising; it was 22.1 of untreated fiber (20 wt%) reinforced HDPE compared to 25.1 of silane treated fiber (20%) reinforced HDPE. This increase in fiber content has a positive effect on the mechanical properties of composites. The water absorption of the chemically treated flax fiberbased composites was lower than that of the untreated fiber-based composites.
SURFACE TREATMENTS OF LIGNOCELLULOSIC FIBERS IN THE PRODUCTION OF COMPOSITES FROM DIFFERENT MATRIXES (Atena Editora), 2024
Lignocellulosic natural fibers have been used in the production of composites, whether for reasons of lower production costs, good availability of natural fibers, environmental issues, among others. Improving the characteristics of the new material produced is generally achieved by combining the isolated physical and mechanical characteristics of each material. However, given the importance of ensuring good physical and mechanical properties of composites in industry, there is a need to increase adhesion between fibers and matrices to obtain more resistant and durable composites. Thus, the study aims to explore different surface treatment techniques to reinforce the adhesion between fibers and matrices, and to evaluate the effectiveness of these techniques, by comparing the results obtained with different types of composites with different fibers used as reinforcements. To this end, a bibliographical review was carried out, with the aim of obtaining information about natural lignocellulosic fibers, which are most used as reinforcement in composites, in addition to methods of extraction and processing of lignocellulosic fibers, as well as information about the chemical composition of fibers, physical and mechanical properties, such as density, tensile strength, modulus of elasticity, among others. Furthermore, the research investigates composites reinforced with and without fiber treatments. Surface treatments significantly improve adhesion between fibers and matrices, resulting in composites with better physical and mechanical properties than untreated raw fibers.
Journal of Renewable Materials, 2019
In France, the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector, thanks to their good physicochemical properties, environmental reasons, health neutrality and due to the European Council Directives on the reuse, recycling and valorization of car components and materials. The aim of our study is to investigate biochemical, physicochemical, and mechanical properties of technical flax fibers to evaluate the impact of transformation processes (scutching, hackling, and homogenization) on final properties of associated composite materials. Different chemical analysis such as Van Soest (biochemical fraction measurement), FTIR (Fourier Transform InfraRed spectroscopy), and XRD (X-ray diffraction) were carried out on different process modalities and show that there is no significant difference in terms of biochemical fraction and crystallinity index. By the same token, mechanical behavior shows that Young's modulus is not affected by the transformation process. This result is also observed for thermal behavior. The results highlight the fact that the transformation processes of technical fibers do not really affect their physicochemical and mechanical performances.
A Study on Flax Fiber-Reinforced Polyethylene Biocomposites
Applied Engineering in Agriculture, 2009
Flax straw and flax fibers are renewable resource and have potential for use in the manufacturing industry. In this study, flax fiber (including 58% flax shives by weight) was studied as a material to be added into polyethylene (high density polyethylene and linear low density polyethylene) in 10% by mass and processed through extrusion and injection molding to biocomposites. Five surface modification methods on flax fibers were carried out and scanning electronic micrographs were taken to analyze the surface characteristic. The biocomposite tensile strength increased and moisture absorption decreased to varying degrees after fiber surface modifications. Among those surface modification techniques, acrylic acid treatment showed a relatively good result in reducing moisture absorption and enhancing tensile properties of biocomposites. It was also found that with increased fiber content (from 10% to 30%), the tensile strength and moisture absorption of biocomposites increased.
Flax fibre and its composites – A review
Composites Part B: Engineering, 2014
In recent years, the use of flax fibres as reinforcement in composites has gained popularity due to an increasing requirement for developing sustainable materials. Flax fibres are cost-effective and offer specific mechanical properties comparable to those of glass fibres. Composites made of flax fibres with thermoplastic, thermoset, and biodegradable matrices have exhibited good mechanical properties. This review presents a summary of recent developments of flax fibre and its composites. Firstly, the fibre structure, mechanical properties, cost, the effect of various parameters (i.e. relative humidity, various physical/chemical treatments, gauge length, fibre diameter, fibre location in a stem, oleaginous, mechanical defects such as kink bands) on tensile properties of flax fibre have been reviewed. Secondly, the effect of fibre configuration (i.e. in forms of fabric, mat, yarn, roving and monofilament), manufacturing processes, fibre volume, and fibre/matrix interface parameters on the mechanical properties of flax fibre reinforced composites have been reviewed. Next, the studies of life cycle assessment and durability investigation of flax fibre reinforced composites have been reviewed.
Materials, 2013
This work describes flax fibre reinforced polymeric composites with recent developments. The properties of flax fibres, as well as advanced fibre treatments such as mercerization, silane treatment, acylation, peroxide treatment and coatings for the enhancement of flax/matrix incompatibility are presented. The characteristic properties and characterizations of flax composites on various polymers including polypropylene (PP) and polylactic acid, epoxy, bio-epoxy and bio-phenolic resin are discussed. A brief overview is also given on the recent nanotechnology applied in flax composites.
Natural Lignocellulosic Fibers as Engineering Materials—An Overview
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science
Recent investigations on the tensile properties of natural cellulose-based fibers revealed an increasing potential as engineering materials. This is particularly the case of very thin fibers of some species such as sisal, ramie, and curaua. However, several other commonly used fibers such as flax, jute, hemp, coir, cotton, and bamboo as well as less known bagasse, piassava, sponge gourde, and buriti display tensile properties that could qualify them as engineering materials. An overview of the strength limits attained by these fibers is presented. Based on a tensile strength vs density chart, it is shown that natural fibers stand out as a relevant class of engineering materials.