Influence of Flax Fibre Hybridization on Mechanical Behaviour of Sisal Fibre-Polypropylene Composites Prepared with an Injection Moulding Machine

Due to their low weight, high specific strength, and low environmental impact, sisal fibre-polypropylene composites have gained popularity. However, the material has a low modulus and poor moisture resistance, among other shortcomings. This study investigated how flax fibre hybridization affects the physical parameters of sisal fibre-polypropylene composites. We used maleic anhydride-grafted polypropylene to improve compatibility between fibres and polypropylene. Adding flax fibres to polypropylene-silica composites resulted in increased tensile strength, flexibility, and impact strength, according to researchers. Water resistance was further improved by adding flax fibres. Tensile strength values of polypropylene-sisal fibre composites filled with 0, 5, 10, 15, and 20 wt% of flax fibres were 29.46, 30.56, 31.57, 33.12, and 34.64 MPa, respectively.

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Bacterial Cellulose Reinforced Flax Fibre Composites: Effect of Nanocellulose Loading on Composite Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.825-826.1063 ◽

2015 ◽

Vol 825-826 ◽

pp. 1063-1067

Author(s):

Marta Fortea-Verdejo ◽

Elias Bumbaris ◽

Koon Yang Lee ◽

Alexander Bismarck

Keyword(s):

Tensile Strength ◽

Bacterial Cellulose ◽

Flax Fibre ◽

The Other ◽

Cellulose Content ◽

Polypropylene Composites ◽

Flax Fibres ◽

Paper Making ◽

Fibre Composites ◽

Composite Properties

Loose hierarchical flax fibres/polypropylene composites were manufactured in a simple way based on a paper-making process in order to include nanocellulose and allow the hornification of the nanofibres in a controlled manner. The effect of flax fibre content on the flax/polypropylene composites and the influence of nanocellulose on the properties of these composites are discussed. By increasing the flax content a slight decrease of the tensile strength and an increase of the Young´s modulus were observed. On the other hand, no significant effect was noticed when increasing the bacterial cellulose content in the composites.

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Laccase-Enzyme Treated Flax Fibre for Use in Natural Fibre Epoxy Composites

Materials ◽

10.3390/ma13204529 ◽

2020 ◽

Vol 13 (20) ◽

pp. 4529

Author(s):

Hanna M. Brodowsky ◽

Anne Hennig ◽

Michael Thomas Müller ◽

Anett Werner ◽

Serge Zhandarov ◽

...

Keyword(s):

Coupling Agent ◽

Interfacial Strength ◽

Fibre Surface ◽

Tensile Tests ◽

Single Fibre ◽

Natural Fibre ◽

Flax Fibre ◽

Specific Strength ◽

Flax Fibres ◽

Afm Micrographs

Natural fibres have a high potential as reinforcement of polymer matrices, as they combine a high specific strength and modulus with sustainable production and reasonable prices. Modifying the fibre surface is a common method to increase the adhesion and thereby enhance the mechanical properties of composites. In this study, a novel sustainable surface treatment is presented: the fungal enzyme laccase was utilised with the aim of covalently binding the coupling agent dopamine to flax fibre surfaces. The goal is to improve the interfacial strength towards an epoxy matrix. SEM and AFM micrographs showed that the modification changes the surface morphology, indicating a deposition of dopamine on the surface. Fibre tensile tests, which were performed to check whether the fibre structure was damaged during the treatment, showed that no decrease in tensile strength or modulus occurred. Single fibre pullout tests showed a 30% increase in interfacial shear strength (IFSS) due to the laccase-mediated bonding of the coupling agent dopamine. These results demonstrate that a laccase + dopamine treatment modifies flax fibres sustainably and increases the interfacial strength towards epoxy.

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Performance of SiO2-impregnated flax fibre reinforced polymers under wet dry and freeze thaw cycles

Journal of Composite Materials ◽

10.1177/0021998320946811 ◽

2020 ◽

Vol 55 (2) ◽

pp. 251-263

Author(s):

Kenneth Mak ◽

Amir Fam

Keyword(s):

Tensile Strength ◽

Mechanical Damage ◽

Tensile Modulus ◽

Flax Fibre ◽

Short Term ◽

Freeze Thaw ◽

Post Exposure ◽

Flax Fibres ◽

Pull Out ◽

Term Performance

Flax fibres are of growing interest as a reinforcing fibre; however, they are susceptible to moisture and have demonstrated poor bond to conventional hydrophobic resins. Although there are multiple approaches to address these issues, research has heavily focused on their short-term performance. In this research program, the performance of flax fibre reinforced polymer (FFRP), manufactured using SiO2-impregnated flax fibre, is assessed for its short-term performance as well as its long-term performance when exposed to wet-dry (WD) and freeze-thaw (FT) cycles. Treated FFRP showed improved bond between the fibre and resin as well as resistance to fibre pull-out. It exhibited a tensile strength of 144 ± 15 MPa and a tensile modulus of 8.6 ± 0.35 GPa. When exposed to WD cycles, delamination between the fibre and resin were observed. The onset of statistically significant mechanical damage occurred after four WD cycles, with a final 3% reduction in strength and a 6% reduction in modulus post-exposure. When exposed to FT cycles, FFRP experienced cracking within the fibre, as well as delamination at the interface. The onset of statistically significant mechanical damage occurred after 50 FT cycles, which manifested as a final 5% reduction in tensile strength and 10% reduction in tensile modulus post-exposure. Regardless of treatment, FFRP demonstrated the same damage mechanisms as untreated variants.

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An Investigation of the Effect of Processing Conditions on the Interface of Flax/Polypropylene Composites

Advanced Composites Letters ◽

10.1177/096369350101000603 ◽

2001 ◽

Vol 10 (6) ◽

pp. 096369350101000 ◽

Cited By ~ 6

Author(s):

N. E. Zafeiropoulos ◽

C. A. Baillie ◽

F. L. Matthews

Keyword(s):

Surface Modification ◽

Composite Materials ◽

Flax Fibre ◽

Natural Fibres ◽

Processing Conditions ◽

Cooling Rates ◽

Polypropylene Composites ◽

Flax Fibres ◽

The Matrix ◽

The Cost

In recent years there has been an increasing interest in using natural fibres as potential reinforcements for polymers. It is well known that the properties of composite materials are controlled by the properties of the matrix and the fibre, as well as of the interface. The most usual methods of strengthening the interface involve the application of surface modification methods on the fibres, or the application of compatibilisers in the matrix. However, it may be possible that one may achieve similar results just by simply controlling the processing conditions, and thus avoiding the application of chemicals that tend to increase the cost. In the present study the effect of cooling rates upon the interface in flax fibre/iPP composites was investigated by means of fragmentation tests. It was found that slower cooling leads to a stronger interface for two different grades of flax fibres; dew retted and green flax.

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Critical Fibre Length and Apparent Interfacial Shear Strength of Single Flax Fibre Polypropylene Composites

Advanced Composites Letters ◽

10.1177/096369359800700303 ◽

1998 ◽

Vol 7 (3) ◽

pp. 096369359800700 ◽

Cited By ~ 12

Author(s):

M.J.A. Van Den Oever ◽

H.L. Bos

Keyword(s):

Shear Strength ◽

Interfacial Shear Strength ◽

Fibre Length ◽

Stress Transfer ◽

Interfacial Shear ◽

Flax Fibre ◽

Polypropylene Composites ◽

Flax Fibres ◽

Shear Yield ◽

The Matrix

The stress transfer in, both elementary and technical, single flax fibre polypropylene composites is studied by determining the critical fibre length and the apparent interfacial shear strength. The influence of improved fibre-matrix interaction is reported and the results are compared with data from literature. The study indicates that the critical fibre length for elementary flax fibres is equal to or even higher than the flax fibre lengths found after extrusion and injection moulding processes. Furthermore, addition of maleic anhydridy modified polypropylene to the matrix results in an apparent interfacial shear strength for elementary flax fibres close to the shear yield strength of the matrix, for technical fibres the interfacial shear strength is somewhat lower.

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CORONA 5 Alloy

Alloy Digest ◽

10.31399/asm.ad.ti0070 ◽

1978 ◽

Vol 27 (5) ◽

Keyword(s):

Fracture Toughness ◽

Tensile Strength ◽

Corrosion Resistance ◽

Density Ratio ◽

Heat Treating ◽

Steel Company ◽

Specific Strength ◽

Strain Fracture ◽

Crucible Steel ◽

Chloride Stress Corrosion Cracking

Abstract CORONA 5 is a titanium alloy developed for applications in fracture-controlled aircraft components. Plane strain fracture toughnesses of 110,000 to 150,000 psi sq.rt. in. (120 to 165 MPa sq.rt. m) have been produced in this alloy at 135,00 psi (930 MPa) tensile strength through a variety of different process histories. The specific strength (strength/density ratio) is superior to that of the Ti-6A1-4V alloy. Resistance to fatigue crack propagation and resistance to chloride-stress-corrosion cracking are comparable to those of Ti-6A1-4V. This datasheet provides information on composition, physical properties, microstructure, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-70. Producer or source: Crucible Steel Company of America, Titanium Division.

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Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽

10.3390/min11070779 ◽

2021 ◽

Vol 11 (7) ◽

pp. 779

Author(s):

Mohamed Gomah ◽

Guichen Li ◽

Salah Bader ◽

Mohamed Elkarmoty ◽

Mohamed Ismael

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Failure Mode ◽

Physical And Mechanical Properties ◽

P Wave ◽

Physical Parameters ◽

Slow Cooling ◽

Heating And Cooling ◽

Natural Rock ◽

The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

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