Effect of silica nanoparticles in kenaf reinforced epoxy: flexural and compressive properties

Kenaf natural fibre is used as a sustainable form of material to reinforce polymeric composite. However, natural fibres usually do not perform as well as synthetic fibres. Silica nanoparticle is a material with high surface area and its high interfacial interaction with the matrix results in its improvement. In this research, silica nanoparticles were introduced into epoxy resin as a filler material to improve the mechanical properties of the kenaf-reinforced epoxy. They were dispersed into the epoxy using a homogeniser at 3000 rpm for 10 minutes. The composites were fabricated by spreading the silica filled epoxy evenly onto the kenaf mat before hot pressing the resin wet kenaf mat. The results show for flexural properties, composites with higher fibre and silica volume content generally had better properties with specimen 601 (60 vol% kenaf and1 vol% silica) having the highest strength at 68.9 MPa. Compressive properties were erratic with specimen 201 (20 vol% kenaf and 1 vol% silica) having the highest strength at 53.6 MPa

Water absorption of environment friendly sugar palm fibre reinforced vinyl ester composites at different fibre arrangements

A study on water absorption of sugar palm fibre reinforced vinyl ester (VE) composites at different fibre arrangements is presented in this paper. Hand lay-up method was used in preparing the composites and water absorption was determined using a balance and water absorption equation. Results revealed that unidirectional fibre composites demonstrate the lowest value of water absorption compared to bidirectional fibre composites (0°/90° and ±45° fibre arrangements) but all composites showed high water absorption compared to neat VE, which may be attributed to incompatibility between fibre and matrix in composites that led to micro bubble and void

Flexural and compressive properties of hybrid kenaf/silica nanopeprintss in epoxy composite

Kenaf fiber like other natural fibers is used as a sustainable form of material to fabricate composite. But natural fibers are generally weaker than synthetic fibers due to the porosity of the fibers making them grow weaker mechanically and physically as time passes. To improve the quality of kenaf reinforced composite, silica nanoparticles was introduced as a filler material. Silica nanoparticle is a material with high surface area contributing to its high interfacial interaction with the matrix resulting in the improvement of the matrix. In this work, the composites were fabricated via vacuum infusion process by creating a system in which the compressed randomly orientated kenaf mat are laid in. The silica nanoparticles are dispersed into the epoxy using a homogenizer at 3000 rpm for 10 minutes before being infused into the fibers. The results shows that generally the inclusion of hydrophobic silica nanoparticles had a detrimental effect on the mechanical properties. However, composites with 2 vol% silica had the best mechanical properties of specimens with silica nanoparticles included at 43.8 MPa and 3.05 GPa for flexural strength and flexural modulus, and 40.0 MPa and 1.15 GPa for compressive strength and compressive modulus, respectively

Physicochemical and thermal properties of lignocellulosic fiber from sugar palm fibers: effect of treatment

Sugar palm fiber (SPF) is one of the prospective fibers used to reinforce polymer composites. The aim of this study is to evaluate the physicochemical, thermal, and morphological properties of SPF after alkali and sea water treatments. The chemical constituents group and thermal stability of the SPF were determined using scanning electronic microscopy (SEM) along with energy dispersive X-ray spectroscopy and thermogravimetric analysis (TGA). Fourier transform infrared spectroscopy was carried out to detect the presence of functional groups in untreated and treated SPF. The SEM images after both treatments showed that the external surface of the fiber became clean as a result. However, the sea water treatment affected the fiber properties physically, while the alkali treatment affected it both physically and chemically by dissolving the hemicellulose in the fiber. The TGA results showed that untreated fiber is significantly more stable than treated fiber. In conclusion, the results show that the fiber surface treatment significantly affected the characterization of the fiber

Kenaf fibre: its potential and review on bending fatigue of hollow shaft composites

The fast growing use of composite in many applications has been focused on sustainable and renewable reinforced composites. Natural fibres were introduced and increasingly used due to their availability and environmental issues. Kenaf is the most common natural fiber used as reinforcement in polymer matrix composites (PMC). Therefore, this study analyzes the bending fatigue for kenaf fiber hollow shaft composite. The wet filament winding technique was used to prepare the composite specimens for the bending fatigue test. Different orientation angles (45° and 90°) and reinforced with aluminum were studied

Sugar palm fibre and its composites: a review of recent developments

The use of natural fibres as reinforcement in composite materials has increased over the years due to the rapid demand for renewable, cost-effective, and eco-friendly materials in many applications. The most common and adopted natural fibres used as reinforcements are flax, kenaf, hemp, jute, coir, sisal, and abaca. However, sugar palm fibre (SPF) as one of the natural fibres is gaining acceptance as a reinforcement in composites, though it has been known for decades in the rural communities for its multipurpose traditional uses. Sugar palm fibre (SPF) is extracted from sugar palm tree typically from its four morphological parts, namely, trunk, bunch, frond, and the surface of the trunk, which is known as Ijuk. In this paper, sugar palm tree, its fibre and composites, and biopolymers derived from its starch are discussed. Major challenges and the way forward for the use of sugar palm fibre and its composites are highlighted. This review also opens areas for further research on sugar palm fibre and its composites for academia and industries

Split-disk properties of kenaf yarn fibre-reinforced unsaturated polyester composites using filament winding method

There are many contributions from synthetic fibres in the world of industrial composites over the years. However, they contain hazardous properties to humans causing irritation when exposed to the skin and eye. Inhalation of fibrous synthetic can cause lung cancer with its deadly effects. There have been studies and researches conducted on natural fibres to replace synthetic fibres as it is believed the latter are more environmental-friendly and pose less health risks to humans. The aim of this study was to investigate hoop tensile properties of the composite hollow shaft for different winding angles and PVC reinforcement produced via the filament winding technique. For this purpose, split-disk tests (according to ASTM D-2290 standard) were performed for the specimens produced with two different winding angles such as 45o and 90o winding angle. By determining the hoop tensile strength and modulus of these specimens, the effects of filament-winding processing parameter in winding angle were evaluated. Experiments successfully showed that the mechanical properties such as tensile properties of kenaf yarn fibre reinforced unsaturated polyester hollow tube at 90° and 45° winding angle with and without PVC. The value was 15% for the different winding angles and 25% for the different winding angles with and without PVC. The results indicate that 90° fibre winding angle kenaf yarn fibre unsaturated polyester with PVC has the highest hoop tensile strength compared with other composite specimens. The experiments concluded that the orientation on fibre angle has a significant impact on the hoop tensile strain, hoop tensile modulus and hoop tensile strength properties

Mechanical properties of hybrid glass/sugar palm fibre reinforced unsaturated polyester composites

A research has been carried out to investigate the mechanical properties of composites made by hybridizing sugar palm fibre (Arenga pinnata) with glass fibre into an unsaturated polyester matrix. Hybrid composites of glass/sugar palm fibre were fabricated in different weight ratios of strand mat glass fibres: sugar palm fibres 4:0, 4:1, 4:2, 4:3, 4:4, and 0:4. The hybrid effects of glass and sugar palm fibre on tensile, flexural and impact properties of the composites were evaluated according to ASTM D5083, ASTM D790 and ASTM D256 respectively. Results have been established that properties of hybrid glass/sugar palm composites such as tensile strength, tensile modulus, elongation at break, toughness, flexural strength, flexural modulus and impact strength are a function of fibre content. The failure mechanism and the adhesion between fibres/matrix were studied by observing the scanning electron micrographs of impact fracture samples. In general, the incorporation of both fibres into unsaturated polyester matrix shows a regular trend of increase in the mechanical properties

Seaweeds as renewable sources for biopolymers and its composites: a review

Background: The rising environmental awareness has driven efforts for the development of renewable materials for various end-use applications. The trend of using biopolymer in combination with organic or non-organic filler has increased rapidly in recent years. Seaweed is a versatile organism that produces various kinds of polysaccharides i.e. agar, carrageenan and alginate that are extensively used in the development of biopolymer. Biopolymers derived from seaweed polysaccharides possess promising features as they are renewable, biodegradable, biocompatible, and environment-friendly. The aims of this paper are to review research related to the seaweed and its biopolymers for various applications. Methods: Research articles related to the seaweed and its biopolymers are reviewed. The summary of seaweed composites and seaweed biopolymers modification are provided. Results: Seaweed has been used for various applications ranging from food, thickening agent, natural medicine, biofuel, biosorbent material, etc. Seaweed was also used as reinforcement to improve the mechanical properties of polymer composites. Various modifications have been done on seaweed biopolymer to improve the properties of the materials such as blending with other polymers, the addition of compatibilizer, and reinforcement with other materials. The potential of seaweed polymers i.e. agar, carrageenan, and alginate in various applications such as packaging and pharmaceutical show promising characteristics for applications. Conclusion: Seaweed is a highly potential source for renewable biopolymers. These biopolymers have shown great characteristics for various applications due to their unique film-forming ability and excellent mechanical properties. These properties can be further improved following various modification techniques i.e. reinforcement and blending. The potential of seaweed as filler in polymer composites provides evidence to improve the thermal, physical, and mechanical properties of the synthetic polymer matrix. It can be concluded that seaweed is a highly potential renewable resource for the development of biocompatible and environmentally friendly materials