Idowu David Ibrahim

Mechanical properties of sisal fibre-reinforced polymer composites: a review

Abstract There has been a growing interest in the utilization of sisal fibres as reinforcement in the production of polymeric composite materials. Natural fibres have gained recognition as reinforcements in fibre polymer–matrix composites because of their mechanical properties and environmental friendliness. The mechanical properties of sisal fibre-reinforced polymer composites have been studied by many researchers and a few of them are discussed in this article. Various fibre treatments, which are carried out in order to improve adhesion, leading to improved mechanical properties, are also discussed in this review paper. This review also focuses on the influence of fibre content and fabrication methods, which can significantly affect the mechanical properties of sisal fibre-reinforced polymer composites.

The use of polypropylene in bamboo fibre composites and their mechanical properties – A review

Bamboo fibre has gained significant interest as a sustainable reinforcement fibre in natural fibre/polymer composites, which is as a result of specific mechanical properties and being a biodegradable material compared to glass fibres. The article also gives a summary of how to improve the mechanical properties of bamboo fibre reinforced polypropylene (BFRP) composites as presented in various researches and the methodology of attaining these ultimate properties of bamboo fibres with polymeric matrices leading to improved BFRP. Mechanical properties of BFRP composites are improved by introducing coupling agent. Fibre treatment and nanoclay addition, in the right proportion, as reported have improved mechanical properties of BFRP composite.

Impact of Surface Modification and Nanoparticle on Sisal Fiber Reinforced Polypropylene Nanocomposites

The use of plant fibers, polymer, and nanoparticles for composite has gained global attention, especially in the packaging, automobile, aviation, building, and construction industries. Nanocomposites materials are currently in use as a replacement for traditional materials due to their superior properties, such as high strength-to-weight ratio, cost effectiveness, and environmental friendliness. Sisal fiber (SF) was treated with 5% NaOH for 2 hours at 70°C. A mixed blend of sisal fiber and recycled polypropylene (rPP) was produced at four different fiber loadings: 10, 20, 30, and 40 wt.%, while nanoclay was added at 1, 3, and 5 wt.%. Maleic anhydride grafted polypropylene (MAPP) was used as the compatibilizer for all composites prepared except the untreated sisal fibers. The characterization results showed that the fiber treatment, addition of MAPP, and nanoclay improved the mechanical properties and thermal stability and reduced water absorption of the SF/rPP nanocomposites. The tensile strength, tensile modulus, and impact strength increased by 32.80, 37.62, and 5.48%, respectively, when compared to the untreated SF/rPP composites. Water absorption was reduced due to the treatment of fiber and the incorporation of MAPP and nanoclay.

Electrical Conductivity of Cu and Cu-2vol.% Nb Powders and the Effect of Varying Sintering Temperatures on their Mechanical Properties Using Spark Plasma Sintering

The growing demand for relatively inexpensive non-hazardous copper alloys with a good combination of electrical conductivity and high strength has led to increasing researches on Cu-Nb alloys for their excellent predictions over Cu-Be alloys. Cu-2vol.% Nb was produced using spark plasma sintering and the effect of the additive on its electrical conductivity, densification, hardness, corrosion resistance and wear resistance were investigated. It was observed that the additive improved the electrical conductivity of Cu powder from 0.28 to 5.89 S/m within 19–406 ∘C. Relative densities of 97.08% for Cu-2vol.% Nb and 97.33% for pure Cu were obtained at 600 ∘C, while at 650 ∘C, they were 96.08 and 96.82% respectively. The microhardness values were 77 and 72 Hv0.1at 600 ∘C, while at 650 ∘C, they were 83 and 66 Hv0.1 for Cu-2vol.% Nb and pure Cu respectively. The corrosion potential of Cu-2vol.% Nb was noble with a lower anodic current density, suggesting better corrosion resistance at 600 ∘C. Cu-2vol.% Nb showed a better wear resistance at 600 ∘C and an improved electrical conductivity at 650 ∘C.

Improving the thermal and flame resistance properties of polyolefins

Abstract The thermal properties of polymers play a significant role in determining the environment where they can be applied. Most polyolefins have poor thermal properties such as low melting temperature, poor specific heat capacity, and conductivity just like most polymers. Also, as a matter of requirement by law, most polymers including polyolefins are required to have low flammability properties which is achieved by the addition of flame retardants (FRs) to the polyolefins during compounding. Improving on these aforementioned properties will go a long way to widen the present areas of application. Therefore there is the need to constantly review the processes and measures put in place to improve these important properties of polyolefins. The chapter takes a critical look at the current efforts by scientists in improving the thermal and FR properties of polyolefins. However, most works showed that blending of the polyolefins with other polyolefins or polymers, compounding with nanoparticles or treated fibres are some of the common ways this improvement can be achieved.

The use of polyolefins in geotextiles and engineering applications

Abstract Geotextiles form part of geosynthetic materials used in civil, environmental, and agricultural engineering. Geotextile materials have four main functional applications that include: separation, filtration, drainage, and reinforcement. The increased use of geotextiles may be attributed to various properties, such as puncture resistance, tensile strength, burst resistance, tenacity, and frictional resistance, permeability, to name a few. In the successful application of geotextiles, natural fibre-based geotextiles have little contribution: thus there is the need for improvement of their properties for them to adequately compete with synthetic geotextiles. There is also the need for awareness about other areas where geotextiles can function. One of such areas is the prevention of rapid moisture evaporation from the soil in agriculture. Indeed, polyolefin geotextiles have contributed meaningful innovation in the engineering field.

Thermoplastic-Thermoset Nanostructured Polymer Blends

Polymer blends are presently attracting both scientific and industrial interest because of their potentials as economical alternatives to more expensive engineering polymers and non-polymeric materials. More importantly, nanostructure polymer blends could lead to the design and production of low-cost materials with valuable properties in comparison to conventional polymer blends. However, thermoplastics/thermosets blends are problematic because such blends naturally tend to phase separation on the macroscopic scale. Therefore, controlling the phase behavior and morphology by reducing phase size and improving interfacial adhesion become key factors in converting these immiscible blends into useful polymeric products. This can be achieved by adding some copolymers as compatibilizers. Also, addition of nanoparticles can reduce interfacial tension and improve miscibility between polymers and thus have significant effect on phase behavior of polymer blends. Some of the methods of blending are melt extrusion, higher shear processing, physical blending, and reactive blending.