Recent Development of Flax Fibres and Their Reinforced Composites Based on Different Polymeric Matrices (original) (raw)
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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.
Chemical modification of flax reinforced polypropylene composites
Composites Part A-applied Science and Manufacturing, 2009
This paper presents an experimental study on the static and dynamic mechanical properties of nonwoven based flax fibre reinforced polypropylene composites. The effect of zein modification on flax fibres is also reported. Flax nonwovens were treated with zein coupling agent, which is a protein extracted from corn. Composites were prepared using nonwovens treated with zein solution. The tensile, flexural and impact properties of these composites were analysed and the reinforcing properties of the chemically treated composites were compared with that of untreated composites.
Processing and properties of the flax fibre/polypropylene composites
Polimery, 1995
Treatment of the surface of flax fibre with dimethylurea (DMU) made it possible to prepare flax fibre/polypropylene (PP) composites with good mechanical properties. The formation of DMU layer on fibre surface was confirmed with the use of SEM and FTIR methods. The conditions of preparing and compression moulding of flax fibre/PP composites were given.
Polymer Journal, 2007
Binary vinyl monomers such as methylmethacrylate (MMA)/Ethylacrylate (EA), MMA/Acrylonitrile (AN) and MMA/Acrylic acid (AA) have been graft co-polymerized onto flax fibers under the influence of microwave radiations (MWR). Various reaction parameters have been optimized and maximum grafting (25%) was observed in reaction time of 30 min at 210 W microwave power. Flax-g-copolymers thus prepared were used as reinforcing material in the preparation of flax-phenolic composites. Wear resistance was maximum with reinforcement of Flax-gpoly(MMA/AA). Composites reinforced with Flax-g-poly(MMA/EA) showed better tensile strength and can bear load upto 225 N with extension of 3.28 mm and composites reinforced with Flax-g-poly(MMA/AA) showed better compressive strength and can bear load upto 1000 N with compression of 1.74 mm. Maximum values of MOR, MOE and SP were found to be 108.0 N/mm 2 , 5295.62 N/mm 2 and 99.29 N/mm 2 for the composites reinforced with Flax-g-poly-(MMA/AA). On grafting of flax fibers with vinyl monomers, fibers become more and more moisture retardant. It has been found that strength of Flax-g-copolymers was found more than that of raw flax fibers. Flax-g-poly(MMA/ AA) has been found to show good thermal stability in comparison to other graft co-polymers and raw flax fibers. Phenol-formaldehyde (PF) composites reinforced with graft co-polymers of flax fibers showed better mechanical properties in comparison to composites reinforced with raw flax fibers. Composites reinforced with Flax-g-poly(MMA/AA) showed the increased values of MOR, MOE and SP. [
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.
Journal of Composite Materials, 2019
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 treatments are required. Silane treatment has been widely used to modify hygroscopic properties of natural fibers. In this study, a new method of silane treatment has been developed without the prehydrolysis and curing/dehydration of silanol groups. To do so, flax fibers were modified through 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO)-mediated oxidation followed by direct application of the amino-silane. The fiber/matrix interfacial adhesion was examined by measuring interlaminar shear strength. Thermogravimetric analysis and dynamic mechanical analysis were performed to study the thermal resistance and thermomechanical properties of the composites. The results revealed that fiber/matrix adhesion was improved in the oxidized silanized fiber composite. In addition, water absorption was significantly reduced (20%) in the oxidized silanized fiber reinforced composite compared with the as-received one.
Specific features of flax fibres used to manufacture composite materials
International Journal of Material Forming, 2018
The use of composite materials reinforced by flax fibres has been increasing steadily over the last 20 years. These fibres show attractive mechanical properties but also some particularities (naturally limited length, presence of a lumen, fibres grouped in bundles in the plant, complex surface properties and composition). An analysis of the available literature indicates that the quality of the composite materials studied is not always optimal (high porosity, incomplete impregnation, heterogeneous microstructure, variable fibre orientation). This paper reviews published data on the specific nature of flax fibres with respect to manufacturing of biocomposites (defined here as polymers reinforced by natural fibres). All the important steps in the process which influence final properties are analyzed, including the plant development, retting, fibre extraction, fibre treatment, preform preparation, available manufacturing processes, the impregnation step, fibre cell wall changes during processing and fibre/matrix adhesion.
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,
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.