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The combination of lightweight, durable, and flexible elastomer nanocomposites presents a unique set of features that make them highly promising for a range of several engineering applications. Present work investigates the performance of the mechanical and electrical characteristics of a nanocomposite produced by combining silicon rubber (SR) with nano-Graphene, copper oxide (CuO). Two roll mixing followed by compression moulding is used to manufacture different configurations of Graphene/CuO/SR nano composite. Nano composites specimens are fabricated with 1, 2, 4, and 8 wt % of graphene with fixed 1 % CuO. There has been a discernible improvement of 146.52 % in the mechanical properties and 18.1 % in electrical performance. This improvement is supported by the FESEM morphological analysis of fractured surfaces. It has been observed that the optimized loading of 8 wt % of Graphene gives the best performance. The strong interfacial interaction between the Graphene/CuO and SR is responsible for the performance gain.

This review presents a comprehensive overview of recent trends, advances, and challenges in the use of natural fiber composites. This section begins by discussing the growing adoption of bio-based fibers because of their eco-friendly nature and cost-efficiency, focusing particularly on plant-based fibers. A bibliometric analysis will be conducted to evaluate the publication frequency and research trends in this domain. Furthermore, the structural compositions of natural fibers, including cellulose, hemicellulose, lignin, pectin, and wax, were elucidated, highlighting their significance in composite material engineering. The extraction methods of natural fibers, including retting and mechanical decortication, are discussed, along with their implications for fiber quality. The limitations associated with natural fibers, including their hydrophilicity and poor mechanical properties, compared with their synthetic counterparts are addressed. Various surface-treatment methods, particularly physical and chemical ones, were explored to enhance fiber compatibility with polymer matrices. The abstract delves into the principles, techniques, and effects of physical and chemical treatments on natural fibers, emphasizing their role in improving the surface characteristics, interfacial adhesion, and overall mechanical properties of composites. Furthermore, specific studies investigating the impact of physical and chemical treatments on natural fibers are summarized, elucidating the observed changes in fiber morphology, chemical composition, and mechanical properties.

Hybridizing natural and synthetic fibers is thought to be an alternate technique for achieving the desired balance between the mechanical performance and sustainability of fiber metal laminates (FMLs). The aluminum (Al)/pineapple leaf fiber (PALF)/carbon fiber (CF) reinforced epoxy composites with five stacking sequences were fabricated by the vacuum-assisted resin transfer molding (VARTM) method. The effects of the hybridization and layering sequence on mechanical and viscoelastic properties have been investigated by the hardness, interlaminar shear strength (ILSS), and Izod impact test, along with dynamic mechanical analysis (DMA). The study found that A1 (ACPCA) showed significant improvements over non-hybrid AP (APPPA), with 86.50% better ILSS and 59.59% higher impact strength. Compared to A2 (APCPA), A1’s ILSS and impact strength were 26.26% and 38.38% better, respectively, due to two CF layers. Hybrid FML A3 (CPAPC) had the lowest impact strength at 97.77 kJ/m2 among FMLs with aluminum outer layers. DMA tests showed all hybrids were stiffer than non-hybrid AP, with A1 having superior viscoelastic properties. This suggests PALF and CF in natural fiber metal laminates (NFMLs) could be promising for automotive applications.

ABSTRACTRecent developments of green technology promote the rising attraction toward developing high-performance and environmentally friendly pultruded products from naturally derived resources. Some factors that attract attention to developing pultruded biocomposites are their lightweight properties, recyclability, and economical and environmentally superior alternatives to synthetic fibers in commercial applications. Researchers have studied that the environmental crisis caused by conventional synthetic materials can be reduced significantly by using sustainable materials instead. This paper aims to review the potential of plant fibers to be used in pultruded composite manufacturing to reduce and replace the use of synthetic materials in pultruded structures. It was found that kenaf and jute fibers have been extensively studied in pultruded plant fiber reinforced composites and pultruded glass/plant fiber reinforced hybrid composites for their mechanical and physical properties under various test parameters. Overall, pultruded PFCs have recorded good mechanical properties but have limitations in water absorption properties for outdoor applications. An overview of the optimum process parameters, limitations, and potential applications of pultruded PFCs are also outlined. Finally, this review summarizes the future scopes and expectations, providing researchers and industrialists with a vision for deeper investigation in developing pultruded PFCs.

This study introduces a novel methodology for enhancing the efficiency of solar-powered unmanned aerial vehicles (UAVs) through azimuthal solar synchronization and aerodynamic neuro-optimization, leveraging the principles of slime mold neural networks. The objective is to broaden the operational capabilities of solar UAVs, enabling them to perform over extended ranges and in varied weather conditions. Our approach integrates a computational model of slime mold networks with a simulation environment to optimize both the solar energy collection and the aerodynamic performance of UAVs. Specifically, we focus on improving the UAVs’ aerodynamic efficiency in flight, aligning it with energy optimization strategies to ensure sustained operation. The findings demonstrated significant improvements in the UAVs’ range and weather resilience, thereby enhancing their utility for a variety of missions, including environmental monitoring and search and rescue operations. These advancements underscore the potential of integrating biomimicry and neural-network-based optimization in expanding the functional scope of solar UAVs.

Food security is critical for promoting health and well-being and achieving sustainable development, especially in developing countries. Despite the recent efforts to improve it, food security is still a concern due to the rapid increase in populations, conflicts, and natural disasters worldwide. Universities, particularly agricultural universities, play an essential role in addressing food security issues by researching, developing new technologies, and providing education and training to farmers and other stakeholders. The main objective of this review is to discuss the role of universities and integrated farming in ensuring food security. Specifically, this paper reviews the importance of universities and focuses on their role in ensuring and promoting food security in Malaysia. It includes a brief overview of the different types of integrated farming methods that can be used to improve food security and finally discusses the Student Farmer Entrepreneur program, which can be crucial in promoting food security by increasing agricultural productivity, promoting local food production, encouraging sustainable agriculture practices, and supporting rural development. This review also considers the significant impact of the Malaysian government and universities on food security. With integrated farming and the Student Farmer Entrepreneur program, food security can be further improved.

This review paper aims to understand the current processing plant maintenance systems and further identify on-stream phased array corrosion mapping (PACM) to reduce turnaround maintenance (TAM) activity during plant operations. Reducing the TAM duration and extending the TAM interval are common goals of most researchers. Thus, a detailed review was performed to understand the maintenance systems and the problems faced. Furthermore, a review of the current PACM application and the possibility of applying it during on-stream inspection was also performed. PACM has better detectability for localized corrosion, and the results can be obtained for a range of thicknesses, which is the main advantage of this method. However, applying PACM during on-stream inspections at elevated temperatures presents challenges owing to the limitations of the ultrasonic properties and increased probe contact. Future research is needed to evaluate the effectiveness of PACM on piping systems that can be utilized for inspection during plant operation at elevated temperatures. This will enable the detection of general and localized corrosion in common materials, thereby reducing the TAM duration and extending TAM intervals. Detecting and monitoring corrosion growth without shutdown is critical for ensuring the safety and reliability of the processing plants. This literature review provides a more precise direction for future research to address these challenges and to advance the field of on-stream corrosion monitoring.

The research’s aim is to investigate the energy absorption, free-fall drop analysis, and failure analysis of Palm (P)/kenaf (K) fiber-reinforced MWCNT-phenolic composites. 3P:7K reinforced MWCNT–phenolic composites were made using manual mixing and hot pressing at 150°C with a pressure of 10 tonnes. Energy absorption was investigated using a drop weight impact tester. Free-fall drop test was performed to analyze the performance of the aircraft tray table prototype. Non-destructive testing was carried out to investigate the damage mechanism. The results demonstrate that as the impact energy increased from 1.50 J to 3.0 J, the crack length increased. There is a difference of 3% to 15% in the crack sizing between dye penetration and Digital Detector Array (DDA), indicating that DDA is more accurate. In the free-fall drop test, small cracks were detected in the dye penetration method on the prototype. The DDA approach, however, did not reveal any defects. The agglomerations were observed through DDA and Computed tomography. In this study, the hybrid CR/kenaf reinforced MWCNT modified phenolic composites exhibit superior performance that can act as an efficient and eco-friendly material for aircraft tray table application by preserving natural resources.

This study aims to investigate the effect of sodium hydroxide (NaOH) treatment on the strength and stiffness of Cyrtostachys renda (CR) leaf stalk fibers, which could potentially serve as reinforcement for polymer composites. Chemical treatment was performed with NaOH concentrations of 1, 3, and 5 wt% at a soaking time of 1 and 2 hours. The tensile strength, interfacial shear strength (IFSS) and the surface morphology of the fibers were investigated. Based on statistical analysis, the concentration of NaOH significantly affected the tensile strength, while both the concentration of NaOH and treatment duration influenced the IFSS. Increases of 130% in tensile strength and of 423% in interfacial shear strength for the fiber treated at NaOH concentration of 3% at 1 hour soaking time were found, as well as an increased crystallinity index by 12% compared to untreated CR fiber. SEM analysis revealed that shrinkage of hollow structure by the NaOH treatment occurred and subsequently fiber get denser. It can be concluded that fiber treatment with 3% NaOH for 1 hour soaking time is ideal to enhance the fiber properties. Therefore, alkali (NaOH) treated CR fiber could be a potential candidate as reinforcement in polymer composite for structural and automotive components.

Lightweight elastomer nanocomposites have several uses in the automotive and aerospace industries. There ought to be no compromises in terms of efficiency, durability, or performance when it comes to new technological products. This results in the ongoing quest for innovative materials. This study contributes to the development of graphene-reinforced silicone rubber by evaluating its mechanical and tribological properties. The two-roll mill mixing process, followed by the moulding step, is utilised in commercial nanocomposites preparation. As a result, the man-made composite can be justified financially. The moulding process was carried out at 170 °C, and the final curing took place at 200 °C for 4 h. Testing is done using filler weight percentages of 0, 1, 3, 5, and 7% graphene to determine the optimal filler weight %. The mechanical performance of silicon rubber was enhanced by over 213% when the graphene weight percentage was increased. With increasing load, the coefficient of friction decreases, with the lowest value found at 3% graphene by weight. The coefficient of friction and the specific wear rate were discovered to vary with sliding speed.

Due to their superior advantage of strength-to-weight ratio, composite materials are mostly preferred over conventional materials. However, machining composite materials is a big challenge to industries due to their extreme heterogeneity. Several machining operations are required when the composites are brought to service; among all, drilling is one of the primary processes often required during assembling. Several researchers have done process parameter optimizations to attain improved quality drilling on composite materials. The experimental investigation involves a lot of effort, in terms of time and money, in the manufacturing and testing of the composites. With the invent of high-performance computing and its easy availability, in the recent past, researchers have started to work on the numerical simulation of the drilling process. The present review gives a comprehensive review of numerical modeling using finite element analysis of the drilling process for polymer composites. Numerical study on conventional and non-conventional drilling as well as orthogonal cutting with the effect of material, tool geometry, speed/feed, and temperature are reviewed. This will help the researchers to get a one-stop solution to learn different techniques used in numerical modeling of composite machining.

Precision manufacturing requirements are the key to ensuring the quality and reliability of biomedical implants. The powder bed fusion (PBF) technique offers a promising solution, enabling the creation of complex, patient-specific implants with a high degree of precision. This technology is revolutionizing the biomedical industry, paving the way for a new era of personalized medicine. This review explores and details powder bed fusion 3D printing and its application in the biomedical field. It begins with an introduction to the powder bed fusion 3D-printing technology and its various classifications. Later, it analyzes the numerous fields in which powder bed fusion 3D printing has been successfully deployed where precision components are required, including the fabrication of personalized implants and scaffolds for tissue engineering. This review also discusses the potential advantages and limitations for using the powder bed fusion 3D-printing technology in terms of precision, customization, and cost effectiveness. In addition, it highlights the current challenges and prospects of the powder bed fusion 3D-printing technology. This work offers valuable insights for researchers engaged in the field, aiming to contribute to the advancement of the powder bed fusion 3D-printing technology in the context of precision manufacturing for biomedical applications.

To address the weight, cost, and sustainability associated with fibreglass application in structural composites, plant fibres serve as an alternative to reduce and replace the usage of glass fibres. However, there remains a gap in the comprehensive research on plant fibre composites, particularly in their durability for viable structural applications. This research investigates the fatigue and impact properties of pultruded kenaf/glass-reinforced hybrid polyester composites tailored for structural applications. Utilising kenaf fibres in mat form, unidirectional E-glass fibre direct roving yarns, and unsaturated polyester resin as key constituents, pultruded kenaf/glass hybrid profiles were fabricated. The study reveals that pultruded WK/UG alternate specimens exhibit commendable fatigue properties (18,630 cycles at 60% ultimate tensile strength, UTS) and fracture energy (261.3 kJ/m2), showcasing promise for moderate load structural applications. Notably, the pultruded 3 WK/UG/3WK variant emerges as a viable contender for low-load structural tasks recorded satisfactory fatigue properties (10,730 cycles at 60% UTS) and fracture energy (167.09 kJ/m2). Fatigue failure modes indicate that the stress applied is evenly distributed. Ductile failures and delaminations during impact test can be attributed to damping and energy absorbing properties of kenaf fibres. Moreover, incorporating kenaf as a hybrid alternative demonstrates substantial reductions in cost (35.7–50%) and weight (9.6–19.1%). This research establishes a foundation for advancing sustainable and efficient structural materials and highlights the significant role of materials design in shaping the future of engineering applications.

In this paper, a review of natural fibers composites used in protective armors for ballistic applications like bulletproof vests is presented. It seeks to compile the results and establish natural fiber composites as an alternative to absolute synthetic composites used for the same application. The review assesses the latest articles under two categories viz. only natural fibers and hybrid composites with natural and synthetic fibers. It covers a range of fibers from flax, basalt, curaua, kenaf, aramid, jute, coir, and hemp. The study systematically classifies the composites based on the ballistic limit they exhibit and the back face signature measured during standardized ballistic testing. In accordance with the results, the findings are compared against standard materials such as Kevlar used in ballistic armors. The hybrid composites are seen to present superior properties in comparison to plain natural fiber composites. Natural fibers provide an ecological and economical alternative to existing composites. The review shows promising results and immense future scope for natural fibers in the area of ballistic applications and they must be actively considered for replacing synthetic fibers in armor.

Over the past few years, there has been an increasing fascination with electric unmanned aerial vehicles (UAVs) because of their capacity to undertake demanding and perilous missions while also delivering advantages in terms of flexibility, safety, and expenses. These UAVs are revolutionizing various public services, encompassing real-time surveillance, search and rescue operations, wildlife assessments, delivery services, wireless connectivity, and precise farming. To enhance their efficiency and duration, UAVs typically employ a hybrid power system. This system integrates diverse energy sources, such as fuel cells, batteries, solar cells, and supercapacitors. The selection of an appropriate hybrid power arrangement and the implementation of an effective energy management system are crucial for the successful functioning of advanced UAVs. This article specifically concentrates on UAV platforms powered by batteries, incorporating innovative technologies, like in-flight recharging via laser beams and tethering. It provides an all-encompassing and evaluative examination of the current cutting-edge power supply configurations, with the objective of identifying deficiencies, presenting perspectives, and offering recommendations for future consideration in this domain.

Cyrtostachys renda (CR) and Ptychosperma macarthurii (PM) fibers, as new cellulosic fibers were studied. The objective of this research is to evaluate the fibers from stem, leaf stalk, and frond of these two plants as reinforcement in the polymer composites. The density, chemical composition, functional group, crystallinity index, and thermal stability were studied for CR and PM fibers. From the analysis, the density and thermal stability of both leaf stalk fibers are found almost similar. The highest crystallinity index (55.67%) of the leaf stalk of CR was attributed to the highest cellulosic content (38.99%) and the functional group (C-H stretching). From the results, the optimized properties were found for the leaf stalk of CR fiber. The tensile strength, interfacial shear strength (IFSS), morphology of the leaf stalk of CR were explored. The ultimate tensile strength, Young modulus, and IFSS of the leaf stalk of CR is 51.82 ± 9.41 MPa, 0.69 ± 0.18 GPa, and 3.27 ± 0.5 MPa, respectively. The Scanning Electron Microscopy observation revealed that the leaf stalk fiber of CR possesses anti-microbial properties which has been corroborated through the presence of silica bodies over the fiber surface. Hence, the leaf stalk of CR acts as a potential reinforcement in the polymeric composites for lightweight applications.

The increasing demand on the production of ankle-foot orthosis (AFO) leads to the implementation of 3D Printing technology into the manufacturing process, due to its fast production, good design optimization, and cost-effectiveness. Now, several research works were made to implement natural composite as the 3D Printer filament to increase the sustainability of the material, as well as reduce the AFO's weight and raw material cost. However, since this AFO will be used on a daily basis, it is significant to understand the weight, fatigue and impact strength of the orthosis since they affect the user's safety. The aim of this paper is to investigate the density, fatigue and impact strength of the printed kenaf/PLA composite for its possible usability for AFO. The filler within the kenaf/PLA composite was varied at 3, 5 and 7 wt. % and extruded to obtain the composite filament, which was used with 3D printer to print out the specimens used for density, impact, and fatigue test. As the amount of fillers increased, the density and impact resistance decreases while fatigue life increases. In conclusion, the results found in the density and fatigue tests show a positive perspective towards its usability for AFO.

As increasing environmental awareness drives the development of biocomposites, the reality is that these material are still far behind in terms of application. While modifications on biocomposites do improve its properties, they are often conducted individually per study and not altogether, which may limit its potential. To expand the marketability of biocomposites, this research covers the hybridization of natural and synthetic fibre, reinforcement of Sodium Hydroxide (NaOH) treated kenaf fibre, reinforcement of organomodified nanoclay, and the use of modified epoxy in the production of the biocomposite. The dispersion of nanoclay in modified epoxy was conducted via sonication while the selected composite fabrication method is hand lay-up. In the flexural test, treated kenaf composites increase by 52% in flexural strength and 46% in flexural modulus, while treated nanocomposites improve by 83% in impact absorbed energy. The rough surface of treated kenaf and fractured composite surface can be seen using a Field Emission Scanning Electron Microscope (FESEM), indicating high interfacial adhesion in treated kenaf composites. Spectroscopy investigation utilising Fourier Transform Infrared (FTIR) revealed that hemicellulose is easier to be removed with alkalization compared to lignin. X-Ray Diffraction Analysis (XRD) displays higher crystallinity in nanocomposites due to nanoclay.

Petrochemical plants use on-stream inspection often to detect and monitor the corrosion on the equipment and piping system. Compared to ultrasonic thickness gauging and pulse-echo A-scan, phased array corrosion mapping has better coverability and can scan a large area to detect general and localized corrosion. This paper’s objective is to obtain documentary evidence for the accuracy of corrosion detection from 30 °C to 250 °C on A36 low-carbon steel by carrying out simulation experiments every 10 °C step. A minimum of three sets of phased array corrosion mapping data in each temperature were collected to study and evaluate the detectability. The data evidence could enhance the confidence level of the plant’s end users in using phased array mapping in the future during inspections. The experiments were found to be insufficiently thorough despite addressing the initial concerns, leaving more area for discussion in further studies, such as expanding the investigation to thicker carbon steel, stainless steel, and wedge materials.

On-stream inspections are the most appropriate method for routine inspections during plant operation without undergoing production downtime. Ultrasonic inspection, one of the on-stream inspection methods, faces challenges when performed at high temperatures exceeding the recommended 52 °C. This study aims to determine the ultrasonic velocity and attenuation with known material grade, thickness, and temperatures by comparing theoretical calculation and experimentation, with temperatures ranging between 30 °C to 250 °C on low-carbon steel, covering most petrochemical equipment material and working conditions. The aim of the theoretical analysis was to obtain Young’s modulus, Poisson’s ratio, and longitudinal velocity at different temperatures. The experiments validated the theoretical results of ultrasonic change due to temperature increase. It was found that the difference between the experiments and theoretical calculation is 3% at maximum. The experimental data of velocity and decibel change from the temperature range provide a reference for the future when dealing with unknown materials information on site that requires a quick corrosion status determination.

In this study, chitosan/sisal/glass fiber (CS/SF/GF) reinforced hybrid polymer composite for femur bone fracture plate was developed. The CS/SF/GF hybrid composite possesses exclusive sandwich assembly and includes epoxy/GF/CS as the peripheral layers and epoxy/CS/SF as the inner layers. The composite arrangement be similar to the human bone assembly spongy interior cancellous medium and stiff peripheral cortical. The objective of this investigation was to determine the fatigue properties of CS/SF/GF hybrid sandwich composites, because cyclical loading is the foremost loads experienced by a femur plate during normal day to day activities such as walking and running. Tensile and fatigue properties were studied as per ASTM (D3039 and D3479) standards. Morphological behaviour of fractured fatigue samples was considered using scanning electron microscope. The biomimetic activity of CS/SF/GF composites was examined using biomimetic mineralization techniques with the help of simulated body fluid (SBF). The tensile study results proved that the A6 hybrid CS/SF/CTS composites impart higher ultimate tensile strength of 146 MPa and tensile modulus of 6.814 GPa compared to other combinations. The fatigue results revealed that the fatigue life of A5 hybrid CS/SF/GF composites withstand more than 1 million cycles (1.20 × 106) compared to other combinations. The presence of bone like apatite layer (Ca, Sr, Pb, Si, Ba, K, Pd and CI) from Simulated Body Fluid (SBF) onto CS/SF/GF layer were confirmed by XRD, SEM-EDAX and FT-IR. Further, the calcium/phosphate (Ca/P) ratio was found to be approximately 1.67 which is needed for the biological apatite layer formation, this proved the formation of apatite layer on the CS/SF/GF composite surface. The experimental test results proved that GF/SF/CTS/EP hybrid composite can be used for orthopaedic bone fracture plate applications.

This paper studies the influence of glass fibre addition and benzoylation treatment on the physical, mechanical and thermal properties of sugar palm composites. Glass fibre (GF) was added in various fibre ratios: 30%, 50% and 70%, related to the amount of sugar palm fibre (SPF). The results obtained revealed that the EP/30TSPF/70 G F composites exhibited the best tensile properties by increasing the tensile strength by 55.7%. For thermal analysis, the results show that EP/TSPF/GF composites had the most improvement in the initial and final degradation temperature. It can be concluded that, benzoylation treatment help improves the adhesion of the SPF to the GF and to the epoxy matrix. Glass fibre addition helps enhanced the characteristics of the SPF composites as the GF overcome the weakness of SPF. This hybrid composites show promising characteristics to be applied for non-structural application as example food tray table.

Background: Coronavirus disease 2019 (COVID-19), a novel pneumonia disease originating in Wuhan, was confirmed by the World Health Organization on January 12, 2020 before becoming an outbreak in all countries. Outbreak situation: A stringent screening process at all airports in Malaysia was enforced after the first case outside China was reported in Thailand. Up to April 14, 2020, Malaysia had reported two waves of COVID-19 cases, with the first wave ending successfully within less than 2 months. In early March 2020, the second wave occurred, with worrying situations. Actions taken: The Government of Malaysia enforced a Movement Control Order starting on March 18, 2020 to break the chain of COVID-19. The media actively spread the hashtag #stayhome. Non-governmental organizations, as well as prison inmates, started to produce personal protective equipment for frontliners. Various organizations hosted fundraising events to provide essentials mainly to hospitals. A provisional hospital was set up and collaborations with healthcare service providers were granted, while additional laboratories were assigned to enhance the capabilities of the Ministry of Health. Economic downturn: An initial financial stimulus amounting to RM 20.0 billion was released in February 2020, before the highlighted PRIHATIN Package, amounting to RM 250 billion, was announced. The PRIHATIN Package has provided governmental support to society, covering people of various backgrounds from students and families to business owners.

3-D E-glass fabric reinforced epoxy composites at 6 mm thickness were fabricated for various orientations of the binder yarn viz. 0°, 30°, 45°, 60° and 90° respectively. Tensile, flexural, interlaminar shear stress tests were conducted to ascertain the influence of binder yarn orientation on the mechanical properties of the composites. The composites with 0° binder yarn orientation showed the best strength followed by 90° whilst the others showed highly depleted traits in comparison. Shear stress induced at the interface of each lamina was seen as the major reason for drop in the strength. A secondary study was carried out to explore the effect of compression factor during fabrication on the mechanical properties of the composites. Laminates with varying thickness namely, 4 mm, 5 mm and 7 mm but, with same number of plies of 3D E-glass fabric at 0° orientation were fabricated. The test results were compared with the results of 6 mm composites from the primary study. The results showed that, compression factor affected the mechanical properties of the composites and had a direct relation with increasing compression factor up to a certain value beyond which a drop in properties was seen. Composites pressed to a thickness of 5 mm showed the best properties. Drop in properties was attributed to close packing of reinforcement and crushing of fibres leading to inefficient stress transfer. Scanning electron microscopy was employed to understand the modes of failure. The major failure modes observed were delamination, matrix cracking and debonding. Based on the results obtained, these composites can be seen as a material system for applications like ballistic armours, structural renovations and automobile components.

This study aims to explore the potential of the NaOH-treated Cytostachys renda fibre to be reinforced in the polymeric composites. The NaOH concentrations were prepared as 1, 3, and 5 wt% for soaking time of 1 and 2 h. The treated fibres were characterized in terms of density, chemical composition, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD), and Thermogravimetric analysis (TGA). The results revealed that the density is improved with an increase in the concentration and soaking time. NaOH treatment has reduced the amorphous hemicellulose and lignin content. On the other hand, the improved crystallinity index by 6% was observed for fibre treated at 3% NaOH for 1 h, along with the enhancement of cellulose content as much as 0.27%. From the FTIR analysis, it was observed that the presence of CH stretching vibration from the ether in the treated fibre for 1 h soaking time would form a strong interaction with the polymeric matrix. The TGA results showed that fibre treated at 3% NaOH for 1 h exhibited the highest thermal stability compared to the untreated and other treated fibres. Therefore, it can be concluded that the fibre treated with 3% of NaOH for 1 h soaking time could act as a potential reinforcement in the polymeric composites for light weight applications.

A finite element model is developed to determine deformation and stresses on a composite wing of unmanned aerial vehicle (UAV) with a tubercle design at the leading edge of the wing. Tubercles, commonly known as protuberances found on the leading edge of a whale pectoral flipper, offering great performance from an aerodynamic perspective. This paper deals with a first order shear deformation theory (FSDT) approach to discover the UAV laminates composite wing model of tubercle leading edge (TLE) with rib-reinforced so that the equivalent stiffness and material properties are obtained from the simulation of finite element analysis using ANSYS. Another structural configuration of design replicating the idea of monocoque concept, whereby foam is used at the leading and trailing edges of the wing. Styrene acrylonitrile (SAN) core foam is used representing high strength-to-weight ratio with its superiority in the mechanical properties of polymeric sandwich composites. The updated static structural analysis from rib-reinforced can be applied to update the wing stiffness distribution of monocoque-foam. The optimum design is concluded from the tabulated deformation and stresses of both wings, where monocoque-foam showed better performance with a reduction in 50.72% of deformation and 35.88% of stress, compared to rib-reinforced design. Keywords: Laminates composite wing, Rib-reinforced, Monocoque-foam, Finite element analysis

Application of synthetic fibres in composites has been raising environmental issues due to carbon emissions from the production site and reliability on non-renewable resources upon production. Hence, this research sets as a preliminary study to select suitable natural fibres to be hybridized with glass fibres for the development of sustainable and high-performance hybrid composites as potential alternative to conventional pultruded fibreglass composites in structural profile applications. In this study, analytical hierarchy process (AHP) was conducted to select the ideal natural fibre as reinforcement in the hybrid pultruded FRP composites suitable for structural applications. Hence, 13 natural fibre candidates were selected as alternatives and six criteria were chosen and analysed to select the best candidate for pultruded hybrid FRP. Criteria such as tensile strength, tensile modulus, density, cellulose content, elongation, and availability of fibres were assigned as the standard of selecting natural fibres for the application intended in this study. Among the 13 alternatives, kenaf was found to be the most suitable reinforcement for the application as it yielded the highest priority vector at 0.1. The results were then validated by carrying out sensitivity analysis to ensure kenaf is the most suitable material for the research.

The use of metallic materials in automotive industry leads to increasing fuel consumption and cost, so trends are starting to use lighter and cheaper materials. In automotive applications, fibers are used in composites because they are stronger, stiffer, and lighter than bulk materials, and they can achieve higher energy absorbing compared to metallic materials. The purpose of this work is to study the potential utilization of natural fibers in the crash energy absorbing applications. The experimental procedures (the principle of a combination of manual layup and vacuum bladder technique) were applied to search the influence of utilizing jute fiber mat on crashworthiness parameters of composite materials with other kinds of fibers such as woven glass fiber reinforced epoxy composites. The study involved corrugated composite tubes with three layers of jute and hybrid glass-jute/epoxy material have been tested in uniaxial quasi-static crush conditions at the speed 10 mm/min. The results exhibit that the tube of jute fiber was somewhat lower than synthetic fibers, but the substitution of one layer of jute fiber with one layer of glass fiber resulted in an improvement in the crashworthiness parameters. As hybrid jute-glass was used, the best result was obtained, where energy absorption and specific energy absorption are improved by 17.75% and 25.122%, respectively.

Non-destructive testing (NDT) is not only primarily concerned with the detection of discontinuities, but also with the mechanical properties. However, the usage of NDT in understanding the mechanical effect that leads to a failure of composites and the damage mechanisms are still not thoroughly studied, as much of the NDT approaches are widely used to maintain the structural integrity to preserve quality assurance. This work aims to investigate the application of infrared thermographic and ultrasonic in evaluating randomly-oriented short-natural-fiber-reinforced phenolic composites. The composites were made from short palm fibers of various sizes between 1.18–0.6 mm, 0.6–0.3 mm, and less than 0.3 mm at 20 and 40 wt%, respectively. The tensile results obtained from the parallel testing of the composites using infrared thermography, where the temperature and time changes on the tested samples were continuously recorded. The peak in the temperature-time graph indicated a macro crack growth and matrix cracking in the form of dissipated energy. Ultrasonic inspection were carried out on the impacted specimens. A scan of the ultrasonic testing on the phenolic composites found presence of a back wall in neat phenolic and was eradicated with fiber reinforcement due to attenuation and energy dissipation. The attenuation coefficient of composites was calculated with the aid of the A-scan. Therefore, it is concluded that ultrasonic inspection on the natural fiber is limited due to the large scattering of wave and energy loss due to attenuation, while infrared thermography is suitable to inspect natural-fiber-reinforced composites when monotonic loadings are applied.

In this study an attempt was made to explore the possibility of substituting 3D E-glass fabric with eco-friendly basalt fabric along with the modification of resin using MWCNTs, a material system about which very limited information exists. The study involved comparing the mechanical properties of two sets of composites. The first set was comprised of 3D orthogonally woven E-glass-reinforced epoxy composites, basalt-reinforced epoxy composites, and hybrid 3D E-glass orthogonally woven/basalt-reinforced epoxy composites while the second set of composites was the same as the first but prepared with resin modified with Multi Walled Carbon Nanotubes (MWCNTs). All the composites were fabricated by hand lay-up and compression molding techniques. To modify the resin for the second set of composites, MWCNTs were dispersed into the epoxy resin with acetone as a surfactant by magnetic stirring and ultra-sonification. Mechanical tests included tensile, flexural, and low velocity impact strength which were evaluated as per standards. Scanning electron microscopy (SEM) was employed to study the fractured surfaces. Results showed that resin modification did not yield any positive results on the mechanical properties of the composites. The highest tensile (364.4 MPa) and flexural strength (345.3 MPa) was obtained for 3D E-glass composites followed by basalt composites and hybrid 3D E-glass/basalt composites while the highest impact strength of 198.42 kJ/m2 was exhibited by the hybrid 3D E-glass/basalt composites. SEM micrographs showed de-bonding between the modified matrix and fiber which was seen as one of the primary causes for relatively poor performance of the composites prepared with modified resin. Fiber breakage, matrix cracking, fiber pull-out, and delamination were the other modes of failure. Results suggest that hybridization with basalt fibers is a much safer, more cost effective, and eco-friendly option over resin modification.

The global need for energy has grown in tandem with mankind’s development and spread. This has resulted in an increase in the use of fossil energy sources, a decline in these sources and an increase in pollution, necessitating the search for renewable energy sources. One of the important ways to reduce pollution resulting from the increasing consumption of fossil energy is to enhance the sources of solar energy, of which photovoltaic cells (PV) are one of its most important tools. Therefore, it was necessary to pay attention to improving its efficiency for it to become a promising source of clean energy. PVs turn solar energy into electricity; however, the amount of electricity generated decreases as the temperature of the cells rises in response to the sun’s heat. Cooling of the optical surfaces is one of the most important elements to consider while running solar PV systems to obtain maximum efficiency. The electrical efficiency of PVs is enhanced when suitable cooling technology is used, and the rate of cell breakdown is reduced over time, extending the life of the PV panels. There are many materials used to remove unwanted heat in PV cells, and in recent years, the focus has been on integrating nanomaterials in specific proportions with traditional cooling materials such as water to improve their thermal properties. As a bio-material that is environmentally friendly, renewable, sustainable, inexpensive and has high mechanical properties, cellulose nanocrystals (CNCs) are one of the most promising materials for improving the properties of cooling materials for cooling PV cells and improving their performance.

In managing the COVID-19 pandemic, the Malaysian government enforced mandatory body temperature screening as a rudimentary form of infection detection at the entry points of establishments and public transportation. However, previous iterations of IoT body temperature screening systems were bulky, fragile, expensive, and designed for personal use instead of the screening of many people. Therefore, a standalone, portable, and rugged IoT-enabled body temperature screening system for detecting elevated temperatures was developed in this research work. This system uses a proximity sensor to detect subjects and determine their body temperature using a non-contact temperature sensor. Body temperature data is displayed on the device and uploaded over a Wi-Fi network to a cloud server for data storage and analysis. From the cloud server, body temperature information is retrieved and displayed on the Blynk IoT client dashboard for remote monitoring. The device also provides alerts for body temperatures above 37.5 °C. The prototype system performed impressively during the assessment. Body temperature readings were impressively accurate compared to a medical-grade non-contact thermometer, with an average variance of less than 1%. Additionally, the system was highly reliable, with a 100% IoT data broadcast success rate.

The main objective of this study is to examine the impact of reinforcements on the strength of natural fiber composites. Recent advancements in natural fiber composites have minimized the usage of man-made fibers, especially in the field of structural applications such as aircraft stiffeners and rotor blades. However, large variations in the strength and modulus of natural fiber degrade the properties of the composites and lower the safety level of the structures under dynamic load. Without compromising the safety of the composite structure, it is significant to enrich the strength and modulus of natural fiber reinforcement for real-time applications. The strength and durability of natural fiber can be enriched by reinforcing natural fiber. The reinforcement effect on natural fiber in their woven, braided, and knit forms enhances their structural properties. It improves the properties of natural fiber composites related to reinforcement with short and random-orientation fibers. The article also reviews the effect of the hybridization of natural fiber with cellulosic fiber, synthetic fiber, and intra-ply hybridization on its mechanical properties, dynamic mechanical properties, and free vibration characteristics, which are important for predicting the life and performance of natural fiber composites for weight-sensitive applications under dynamic load.

Plastics are unavoidable at this times, putting our planet in danger. The Prosopis juliflora (PJ) thorns are collected, processed, and powdered. The mechanical characteristics of these powders are examined when combined with polymer composites. Pores are the main cause of moisture input, hence using powder filler materials reduces the number of pores in the composite, increasing water resistance. The composites are made by altering three parameters: waste plastic content, filler powder composition, and chemical treatment. It was discovered that the integration of thorn powder increased the wear resistance. The composites were tested in accordance with ASTM standards, and the results were optimized. Based on the results, composite specimens were created and tested for validation.

This research focuses on evaluating the effect of Cyrtostachys renda (CR) fiber and the impact of adding multi-walled carbon nanotubes (MWCNT) on the morphological, physical, mechanical, and flammability properties of phenolic composites. MWCNT were supplemented with phenolic resin through a dry dispersion ball milling method. Composites were fabricated by incorporating CR fiber in 0.5 wt.% MWCNT-phenolic matrix by hot pressing. Nevertheless, the void content, higher water absorption, and thickness swelling increased with fiber loading to the MWCNT/phenolic composites. The presence of MWCNT in phenolic enhanced the tensile, flexural, and impact strength by as much as 18%, 8%, and 8%, respectively, compared to pristine phenolic. The addition of CR fiber, however, strengthened MWCNT-phenolic composites, improving the tensile, flexural, and impact strength by as much as 16%, 16%, and 266%, respectively, for 50 wt.% loading of CR fiber. The CR fiber may adhere properly to the matrix, indicating that there is a strong interface between fiber and MWCNT-phenolic resin. UL-94 horizontal and limiting oxygen index (LOI) results indicated that all composite materials are in the category of self-extinguishing. Based on the technique for order preference by similarity to the ideal solution (TOPSIS) technique, 50 wt.% CR fiber-reinforced MWCNT-phenolic composite was chosen as the optimal composite for mechanical and flammability properties. This bio-based eco-friendly composite has the potential to be used as an aircraft interior component.

Nanocomposite made by blending nano-montmorillonite (MMT) and Silicon Rubber (SR) for mechanical and tribological performance is explored in this work. Different configurations of MMT/SR nanocomposite, with 0, 0.5, 2 and 5 wt % of MMT are manufactured by two roll mixing methods. Noticeable improvement in the mechanical and tribological performance is observed, which is also justified by a morphological study of fractured and wear surfaces through SEM. Two percent of MMT loading is found to be the optimum content that shows excellent performance compared to other compositions. The performance improvement can be linked to the good interfacial interaction between the MMT and SR. Statistical modeling through ANOVA is carried out for tribological performance, which reveals the influence of load on the coefficient of friction (COF) and the influence of sliding distance on the wear rate.

This study examined the fatigue behaviour of pineapple leaf fibre/carbon hybrid laminate composites under various stacking sequences. The vacuum infusion technique was used to fabricate the symmetric quasi-isotropic oriented laminates, in which the stacking was varied. The laminate was tested under static and fatigue tensile load according to ASTM D3039-76 and ASTM D3479-96, respectively. Maximum tensile strength and modulus of 119.34 MPa and 6.86 GPa, respectively, were recorded for the laminate with external PALF ply and internal carbon ply oriented at [± 45°2, 0°/90°2]s (PCCP_45090). The fatigue tests showed that PCCP_45090 and CPPC_09045 (with internal PALF ply and external carbon ply oriented at [0°/90°2, ± 45°2]s) exhibited a higher useful life, especially at the high-stress level of the ultimate tensile strength. The normalised stress against the number of cycles showed that the stacking sequences of different ply orientations affected the fatigue behaviour more than the stacking sequences of the material. The laminate stacking sequence significantly affected the hysteresis energy and stiffness evolution. The scanning electron microscopy images showed that the fatigue failure modes included fibre pull-out, fibre breakage, matrix cracking, debonding, and delamination. The study concluded that PCCP_45090 exhibited an outstanding fatigue performance.

This study aims to investigate the effect of AgNPs on the mechanical, thermal and antimicrobial activity of kenaf/HDPE composites. AgNP material was prepared at different contents, from 0, 2, 4, 6, 8 to 10 wt%, by an internal mixer and hot compression at a temperature of 150 °C. Mechanical (tensile, modulus and elongation at break), thermal (TGA and DSC) and antimicrobial tests were performed to analyze behavior and inhibitory effects. The obtained results indicate that the effect of AgNP content displays improved tensile and modulus properties, as well as thermal and antimicrobial properties. The highest tensile stress is 5.07 MPa and was obtained at 10wt, TGA showed 10 wt% and had improved thermal stability and DSC showed improved stability with increased AgNP content. The findings of this study show the potential of incorporating AgNP concentrations as a secondary substitute to improve the performance in terms of mechanical, thermal and antimicrobial properties without treatment. The addition of AgNP content in polymer composite can be used as a secondary filler to improve the properties.

Adequate awareness of sustainable materials and eco-legislation have inspired researchers to identify alternative sustainable and green composites for synthetic fiber-reinforced polymer composites in the automotive and aircraft industries. This research focused on investigating the physical, mechanical, and morphological properties of different hybrid Cyrtostachys renda (CR)/kenaf fiber (K) (10C:0K, 7C:3K, 5C:5K, 3C:7K, 0C:10K) reinforced with 0.5 wt% MWCNT–phenolic composites. We incorporated 0.5 wt% of MWCNT into phenolic resin (powder) using a ball milling process for 25 h to achieve homogeneous distribution. The results revealed that CR fiber composites showed higher voids content (12.23%) than pure kenaf fiber composites (6.57%). CR fiber phenolic composite was more stable to the swelling tendency, resulting in the lowest percentage of swelling rate (4.11%) compared to kenaf composite (5.29%). The addition of kenaf fiber into CR composites had improved the tensile, flexural, and impact properties. The highest tensile and flexural properties were found for weight fraction of CR and kenaf fiber at 5C:5K (47.96 MPa) and 3C:7K (90.89 MPa) composites, respectively. In contrast, the highest impact properties were obtained for 0C:10K composites (9.56 kJ/m2). Based on the FE-SEM image, the CR fiber lumen was larger in comparison to kenaf fiber. The lumen of CR fiber was attributed to higher void and water absorption, lower mechanical properties compared to kenaf fiber. 5C:5K composite was selected as an optimal hybrid composite, based on the TOPSIS method. This hybrid composite can be used as an interior component (non-load-bearing structures) in the aviation and automotive sectors.

The low-velocity impact behaviour of pineapple leaf fiber, PALF reinforce epoxy composite (P), PALF hybrid (GPG), and four-layer woven glass fiber (GGGG) composite was investigated. As for post-impact analysis, the damage evaluation was assessed through photographic images and X-ray computed tomography, using CT scan techniques. The key findings from this study are that a positive hybrid effect of PALF as a reinforcement was seen where the GPG shows the delayed time taken for damage initiation and propagation through the whole sample compared to GGGG. This clearly shows that the addition of fibers does have comparable composite properties with a fully synthetic composite. Through the visual inspection captured by photographic image, the presence of woven fiber glass mat in GPG presents a different damage mode compared to P. Moreover, CT scan results show extended internal damage at the cross-section of all impacted composite.

A finite element (FE) model is developed to study the structural performance on a composite wing of a UAV with a tubercle design at the leading edge of the wing. The experimental study of the designation of the composite at the wing skin is carried out to prove the simulation validity through material characteristics. In this paper, the numerical modeling for simulation is highlighted to correlate the process parameter setting of simulation replicating the actual experimental tests. The percentage difference was calculated to be 11.1% by tensile and 10.47% by flexural. The numerical work applied the study of FE analysis and developed a standardized numerical approach for structural optimization, known as FE-ACP simulation. The significant findings of deformation are obtained according to Schrenk’s aerodynamic loading, while the prediction of failure mode of Tsai–Wu under interaction among stresses and strains was acquired at the seventh and eighth layer of both spars.

Thermogravimetric analysis and differential scanning calorimetry were used to study the thermal degradation and thermal stability of bamboo powder and its composites (EP-BFC) in a nitrogen atmosphere. The thermal stability of EP-BFC decreased as the bamboo filler-loading increased. Compared with epoxy, bamboo powder had a lower thermal stability, which reduced the thermal stability for the higher filler-loading composites. The addition of glass fibre to the EP-BFC improved the thermal stability of the new hybrid composites. Both the hybrid and non-hybrid composites exhibited similar thermal-induced degradation profiles that had only one mass loss step. However, a noticeable difference between the percentage value of the degradation between both the hybrid and non-hybrid composites showed that the EP/G-BFC hybrids were more thermally stable than the non-hybrid EP-BFC. Different materials experienced different activities, which were clearly shown from the DSC analysis. Bamboo fibre and non-fully cured epoxy exhibit exothermic peaks, while fully cured epoxy exhibits an endothermic peak.

The field of bio-inspired design has tremendously transitioned into newer automated methods, yet there are methods being discovered which can elucidate underlying principles in design, materials, and manufacturing. Bio-inspired design aims to translate knowledge from the natural world to the current trends in industry. The recent growth in additive manufacturing (AM)methods has fueled the tremendous growth of bio-inspired products. It has enabled the production of intricate and complicated features notably used in the aerospace industry. Numerous methodologies were adopted to analyse the process of bio-inspired material selection, manufacturing methods, design, and applications. In the current review, different approaches are implemented to utilize bio-inspired designs that have revolutionized the aerospace industry, focusing on AM methods.

The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.

In this paper, the effects of stacking sequence and ply orientation on the mechanical properties of pineapple leaf fibre (PALF)/carbon hybrid laminate composites were investigated. The hybrid laminates were fabricated using a vacuum infusion technique in which the stacking sequences and ply orientations were varied, which were divided into the categories of cross-ply symmetric, angle-ply symmetric, and symmetric quasi-isotropic. The results of tensile and flexural tests showed that the laminate with interior carbon plies and ply orientation [0°, 90°] exhibited the highest tensile strength (187.67 MPa) and modulus (5.23 GPa). However, the highest flexural strength (289.46 MPa) and modulus (4.82 GPa) were recorded for the laminate with exterior carbon plies and the same ply orientation. The fracture behaviour of the laminates was determined by using scanning electron microscopy, and the results showed that failure usually initiated at the weakest PALF layer. The failure modes included fibre pull-out, fibre breaking, matrix crack, debonding, and delamination.

This paper reviews the tensile properties of bamboo fiber reinforced polymer composites (BFRP). Environmentally friendly bamboo fibers have good mechanical properties, which make them suitable replacements for conventional fibers, such as glass and carbon, in composite materials. Better fiber and matrix interaction results in good interfacial adhesion between fiber/matrix and fewer voids in the composite. Several important factors improve matrix-fiber bonding and enhance the tensile properties of BFRP. Coupling agents, such as maleic anhydride polypropylene (MAPP), improve the adhesion of bamboo fibers in the polypropylene (PP) matrix. A high percentage of lignin content in bamboo fibers limits fiber separation, which leads to less matrix absorption between fibers. Steam explosion is the best extraction method for bamboo fibers, although an additional mechanically rubbing process is required for fiber separation. Generally, high fiber content results in good composite performance, but at a certain limit, the matrix does not adhere well with a saturated amount of fibers, and the composite tensile strength decreases. However, the tensile modulus of BFRP is not affected by excess fiber content. Hybridization of bamboo with conventional fibers increases the tensile strength of BFRP. The addition of micro/nano-sized bamboo fibrils into the carbon fabric composites slightly enhances composite strength.

Fiber composites are known to have poor through-thickness mechanical properties due to the absence of a Z-direction binder. This issue is more critical with the use of natural fibers due to their low strength compared to synthetic fibers. Stitching is a through-thickness toughening method that is used to introduce fibers in the Z-direction, which will result in better through-thickness mechanical properties. This research was carried out to determine the mechanical properties of unstitched and silk fiber-stitched woven kenaf-reinforced epoxy composites. The woven kenaf mat was stitched with silk fiber using a commercial sewing machine. The specimens were fabricated using a hand lay-up method. Three specimens were fabricated, one unstitched and two silk-stitched with deferent stitching orientations. The results show that the stitched specimens have comparable in-plane mechanical properties to the unstitched specimens. For the tensile mechanical test, stitched specimens show similar and 17.1% higher tensile strength compared to the unstitched specimens. The flexural mechanical test results show around a 9% decrease in the flexural strength for the stitched specimens. On the other hand, the Izod impact mechanical test results show a significant improvement of 33% for the stitched specimens, which means that stitching has successfully improved the out-of-plane mechanical properties. The outcome of this research indicates that the stitched specimens have better mechanical performance compared to the unstitched specimens and that the decrease in the flexural strength is insignificant in contrast with the remarkable enhancement in the impact strength.

The purpose of the study is to investigate the utilisation of Napier fiber (Pennisetum purpureum) as a source for the fabrication of cellulose nanofibers (CNF). In this study, cellulose nanofibers (CNF) from Napier fiber were isolated via ball-milling assisted by acid hydrolysis. Acid hydrolysis with different molarities (1.0, 3.8 and 5.6 M) was performed efficiently facilitate cellulose fiber size reduction. The resulting CNFs were characterised through Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), particle size analyser (PSA), field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The FTIR results demonstrated that there were no obvious changes observed between the spectra of the CNFs with different molarities of acid hydrolysis. With 5.6 M acid hydrolysis, the XRD analysis displayed the highest degree of CNF crystallinity at 70.67%. In a thermal analysis by TGA and DTG, cellulose nanofiber with 5.6 M acid hydrolysis tended to produce cellulose nanofibers with higher thermal stability. As evidenced by the structural morphologies, a fibrous network nanostructure was obtained under TEM and AFM analysis, while a compact structure was observed under FESEM analysis. In conclusion, the isolated CNFs from Napier-derived cellulose are expected to yield potential to be used as a suitable source for nanocomposite production in various applications, including pharmaceutical, food packaging and biomedical fields.

This study aims to explore the mechanical properties of hybrid glass fiber (GF)/sisal fiber (SF)/chitosan (CTS) composite material for orthopedic long bone plate applications. The GF/SF/CTS hybrid composite possesses a unique sandwich structure and comprises GF/CTS/epoxy as the external layers and SF/CTS/epoxy as the inner layers. The composite plate resembles the human bone structure (spongy internal cancellous matrix and rigid external cortical). The mechanical properties of the prepared hybrid sandwich composites samples were evaluated using tensile, flexural, micro hardness, and compression tests. The scanning electron microscopic (SEM) images were studied to analyze the failure mechanism of these composite samples. Besides, contact angle (CA) and water absorption tests were conducted using the sessile drop method to examine the wettability properties of the SF/CTS/epoxy and GF/SF/CTS/epoxy composites. Additionally, the porosity of the GF/SF/CTS composite scaffold samples were determined by using the ethanol infiltration method. The mechanical test results show that the GF/SF/CTS hybrid composites exhibit the bending strength of 343 MPa, ultimate tensile strength of 146 MPa, and compressive strength of 380 MPa with higher Young’s modulus in the bending tests (21.56 GPa) compared to the tensile (6646 MPa) and compressive modulus (2046 MPa). Wettability study results reveal that the GF/SF/CTS composite scaffolds were hydrophobic (CA = 92.41° ± 1.71°) with less water absorption of 3.436% compared to the SF/CTS composites (6.953%). The SF/CTS composites show a hydrophilic character (CA = 54.28° ± 3.06°). The experimental tests prove that the GF/SF/CTS hybrid composite can be used for orthopedic bone fracture plate applications in future.

Environmental awareness and trends to develop sustainable resources have directed much research attention towards kenaf fibre as an alternative reinforcement in composite manufacturing. Numerous studies have been conducted on kenaf and its hybrid composites. Most studies were conducted on kenaf/glass hybrid composites compared to other kenaf/synthetic hybrid composites. Similar with other materials, mechanical properties were the fundamental knowledge identified by the researcher. Limited studies conducted on other properties have restricted the use of kenaf composites to non-structural applications. To extend the potential of kenaf composites to automotive exterior or other critical applications, studies on impact properties can be a valuable contribution in the material field. This review discusses the mechanical and low velocity impact properties of kenaf/glass hybrid composites reported previously. Percentage loading of fibre, the angle of orientation in woven fibres and the chemical treatment applied to the fibre before compounding are the three major parameters that affect the mechanical and impact properties of the composites. This review provides insights into the mechanical and impact properties of kenaf/glass hybrid composites for future research.