Effect of Aging Process in Different Solutions on Kenaf Fibre Structure and Its Interfacial Adhesion in Epoxy Composites

Interfacial adhesion of kenaf fibres in epoxy composites was investigated using single fibre pull-out test. Several aged kenaf fibres were tested in this work. Two types of kenaf fibres were used in the work, those treated with 6% NaOH and those untreated kenaf fibres. Kenaf fibres were aged in engine oil, water, salt water, and diesel. The pull-out tests were performed using microtensile tests. The tests were performed at 1 mm/min loading rate. Scanning electron microscopy was used to observe the damage on the fibres and the effect of the treatment. The general results revealed that aging of the fibres reduced their strength and interfacial adhesion. Salt water showed the least effect on the strength of the fibres. At most cases, the breakage in the fibres is the main failure. In other words, there is no remarkable effect of aging on the interfacial adhesion since the most impact was on the structure of the fibres

Theoretical study of the effect of orientations and fibre volume on the thermal insulation capability of reinforced polymer composites

In industry, synthetic fibre reinforcements are popular due to their cost-effectiveness and lightweight nature. However, the non-reusability and non-degradability have raised environmental concerns and prompted scientists to explore more environmentally friendly alternatives. Natural fibres are being investigated as potential replacements to address these issues and promote sustainability. This study investigated the effect of fibre loading and orientation on the heat conductivity of polymer resins using a finite element-based numerical model developed in our previous research. The numerical analysis was conducted in ANSYS® modelling and simulation using glass and sisal fibres in combination with three distinct matrix materials (epoxy, polyester, and vinyl ester). Different orientations (parallel, perpendicular, 45°, and normal) and volume of fibre fractions (20–35%) were used for the analysis. The properties of the materials were incorporated into the ANSYS Engineering database, and the composite model was divided into five segments to analyse the heat transfer. The thermal boundary condition was implemented by keeping one side of the cylinder at 120°C. The results showed that the thermal conductivity of the composites decreased as the volume fraction of natural fibres increased. Epoxy-based composites exhibited better insulation performance than polyester and vinyl ester-based composites. This study demonstrated the potential of using natural fibres to improve the thermal insulation properties of composites

Theoretical Study of the Effect of Fibre Porosity on the Heat Conductivity of Reinforced Gypsum Composite Material

In recent years, there has been an increasing demand for engineering materials that possess good mechanical and thermal properties and are cheap and environmentally friendly. From an industrial and academic point of view, there is a need to study the heat conductivity of newly developed polymer composites and the influence of porosity on the insulation performance of polymer composites. Experimental and theoretical studies were conducted on mainly sisal/glass fibre gypsum composites with different fibre volumes (0, 20, 25, 30, and 35 wt.%). The outcomes from the theoretical model in ANSYS have shown that there is a high possibility to simulate the experimental work and high accuracy for reflecting the experimental findings. Moreover, the results show that natural fibre polymer composites with a high-volume fraction of natural fibres have higher insulation performance than synthetic polymer composites with the same volume fraction of synthetic fibres. Furthermore, the results suggest and support that the improved performance of natural fibre-based composites was due at least in part to the internal porosity of the fibres

The mechanical performance of sugar palm fibres (Ijuk) reinforced phenolic composites

Sugar palm fibres are one of the natural fibres which have many features and need further study to understand their properties. The aim of this work is to investigate the flexural, compressive and impact properties of sugar palm fibres reinforced phenolic composites. Sugar palm fibres were used as a filler (particle size 150 μm) and with loading of 0, 10, 20, 30, and 40 vol.%. The fibres were treated by sea water and then fabricated into composites by hot press technique. Flexural, compressive, and impact tests were carried out as per ASTM D790, ASTM D695-08a, and ASTM D256 standards, respectively. Scanning electron microscopy (SEM) was used to investigate the morphology and the interfacial bonding of the fibres-matrix in composites. The results show that the mechanical properties of the composites improve with the incorporation of fibres. The composite of 30 vol.% particle loading exhibit optimum values which are 32.23 MPa, 61.66 MPa, and 4.12 kJ/m2 for flexural, compressive, and impact strength, respectively. This was because good compatibility of fibre-matrix bonding. Consequently, sugar palm fibre is one of the prospective fibres and could be used as a potential resource to reinforcement polymer composite

Eco-friendly composites for brake pads from agro waste: a review

Natural fibers possess unique property densities that make them potential alternative reinforcement materials in synthetic brake pad composites. This article presents a comprehensive review for the potential and possibilities of reinforcing brake pads using natural plant-based fibers. The influential keys to designing brake pad composites are found to be thermal stability, interfacial bond of the matrix with the fiber, thermal fade, effectiveness, and recovery. Besides that, the optimization technique for manufacturing process of eco-friendly brake pads is also covered. It can be concluded that natural fibers can be used as potential materials for designing effective eco-friendly brake pad composites in the near future

Surface modification of natural fibers in polymer composites

Over the past few years, fibrous materials have found widespread applications in different technological areas including the automotive industry due to their versatile properties. Natural fibers, in particular, are cheap, abundant, biocompatible, and biodegradable, which has motivated many researchers worldwide to explore their potential applications in various industrial sectors. Nevertheless, these types of fibers show some limitations such as high moisture absorption and subsequent swelling and degradation, poor fire resistance, nonhomogeneity of their mechanical properties and poor interfacial interactions with polymeric or cementitious matrices. The fibers surface functionalization using different approaches like physical, chemical, or biological could be the solution to overcome most of the drawbacks related to the use of natural fibers, especially the compatibility between the fiber and the polymeric matrix. Herein, a detailed description of the techniques commonly employed in the modification of natural cellulose fibers will be presented. Several examples will also be shown regarding the application of these natural fibers in polymer composites for possible use in automotive applications

Mechanical properties of palm fibre reinforced recycled HDPE

Recently, recycled thermoplastic polymers become an alternative resource for manufacturing industrial products. However, they have low mechanical properties compared to the thermosets. In this paper, an attempt has been made to enhance the mechanical properties of recycled high density polyethylene (HDPE) with chopped strand mat (CSM) glass fibres as a synthetic reinforcement and with short oil palm fibres as a biodegradable (natural) reinforcement. The effects of volume fraction of both synthetic and natural fibres on tensile, compression, hardness, and flexural properties of the HDPE were investigated. The failure mechanism of the composite was studied with the aid of optical microscopy. Tensile properties of the HDPE composites are greatly affected by the weight fraction of both the synthetic and the natural fibres. The higher strength of the composites was exhibited when at higher weight fraction of both natural and syntactic fibres which was about 50 MPa. Date palm fibre showed good interfacial adhesion to the HDPE despite the untreated condition used. On the other hand, treatment of the fibres is recommended for higher tensile performance of the composites