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Composite holds great promise for future materials considering its advantages such as excellent strength, stiffness, lightweight, and cost-effectiveness. Due to rising environmental concerns, the research speed gradually changes from synthetic polymer composites to natural fibre reinforced polymer composites (NFRPCs). Natural fibres are believed a valuable and robust replacement to synthetic silicates and carbon-based fibres, along with biodegradability, recyclability, low cost, and eco-friendliness. But the incompatibility between natural fibre and polymer matrices and higher moisture absorption percentage of natural fibre limitise their applications. To overcome these flaws, surface treatment of natural fibre and nanofiller addition have become some of the most important aspects to improve the performance of NFRPCs. This review article provides the most recent development on the effect of different nanofiller addition and surface treatment on the mechanical, thermal, and wetting behaviour of NFRPCs. It concludes that the fibre surface treatment and nanofillers in natural fibre polymer composites positively affect mechanical, thermal and water absorption properties. A systematic understanding in this field covers advanced research basics to stimulate investigation for fabricating NFRPCs with excellent performance.

The electrospray deposition (ESD) method was used to deposit carbon nanotubes (CNTs) onto the surface of glass fiber (GF). The morphology of the hybrid CNTs-GF was analyzed using a field emission scanning electron microscope, and the images indicated that the CNTs were uniformly and homogenously deposited onto the GF’s surface. Laminated composite based on GF and hybrid CNTs-GF were then fabricated via vacuum-assisted resin transfer molding. The mode I interlaminar fracture toughness was measured using the double cantilever beam test method. The hybrid CNTs-GF showed a 34% increase in fracture toughness relative to the control sample. The mechanism of interlaminar fracture toughness enhancement was elucidated via fractography, where fiber bridging, adhesive and cohesive failures, hackles, and coarse matrix surface were observed along the crack pathways.

The electrospray deposition method was used to deposit carbon nanotubes (CNT) onto the surfaces of woven carbon fiber (CF) to produce woven hybrid carbon fiber–carbon nanotubes (CF–CNT). Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the woven hybrid CF–CNT. The results demonstrated that CNT was successfully and homogenously distributed on the woven CF surface. Woven hybrid CF–CNT epoxy composite laminates were then prepared and compared with woven CF epoxy composite laminates in terms of their flexural and dielectric properties. The results indicated that the flexural strength, flexural modulus and dielectric constant of the woven hybrid CF–CNT epoxy composite laminates were improved up to 19, 27 and 25%, respectively, compared with the woven CF epoxy composite laminates.

Natural fibre-based materials are gaining popularity in the composites industry, particularly for automotive structural and semi-structural applications, considering the growing interest and awareness towards sustainable product design. Surface treatment and nanofiller addition have become one of the most important aspects of improving natural fibre reinforced polymer composite performance. The novelty of this work is to examine the combined effect of fibre surface treatment with Alumina (Al2O3) and Magnesia (MgO) nanofillers on the mechanical (tensile, flexural, and impact) behaviour of biotex flax/PLA fibre reinforced epoxy hybrid nanocomposites. Al2O3 and MgO with a particle size of 50 nm were added in various weight proportions to the epoxy and flax/PLA fibre, and the composite laminates were formed using the vacuum bagging technique. The surface treatment of one set of fibres with a 5% NaOH solution was investigated for its effect on mechanical performance. The results indicate that the surface-treated reinforcement showed superior tensile, flexural, and impact properties compared to the untreated reinforcement. The addition of 3 wt. % nanofiller resulted in the best mechanical properties. SEM morphological images demonstrate various defects, including interfacial behaviour, fibre breakage, fibre pullout, voids, cracks, and agglomeration.

The growth of the application of electronic devices has created a new form of pollution known as noise or radio frequency interference, electromagnetic radiation, or electromagnetic interference (EMI), which results in the malfunction of equipment. A new carbon-based polymer composite has been unlocked through the discovery of polymer composites. Carbon nanotubes (CNTs) have shown potential as reinforcement fillers in polymer to enhance an EMI shielding material owing to their large specific surface area, well-defined 3D networking structure, and unique electronic structure. The main focus of this review is the role of CNT as fillers in intrinsic conducting polymer and conducting polymer composite. The factors that influence EMI shielding performance are also included in this review. The roles of the size; shape; and electronic, mechanical, and chemical properties of nanomaterials in tuning the EMI shielding effectiveness of polymer hybrid are emphasized. The structural design of CNT polymer composite has been reviewed as well. Future research direction has been proposed to overcome the current technological limitations and realize the most advanced EMI shielding materials for future use. The composites have a potential to replace traditional shielding materials owing to their advantageous properties.

Antimicrobial irradiated seaweed–neem biocomposite films were synthesized in this study. The storage functional properties of the films were investigated. Characterization of the prepared films was conducted using SEM, FT-IR, contact angle, and antimicrobial test. The macroscopic and microscopic including the analysis of the functional group and the gas chromatography-mass spectrometry test revealed the main active constituents present in the neem extract, which was used an essential component of the fabricated films. Neem leaves’ extracts with 5% w/w concentration were incorporated into the matrix of seaweed biopolymer and the seaweed–neem bio-composite film were irradiated with different dosages of gamma radiation (0.5, 1, 1.5, and 2 kGy). The tensile, thermal, and the antimicrobial properties of the films were studied. The results revealed that the irradiated films exhibited improved functional properties compared to the control film at 1.5 kGy radiation dosage. The tensile strength, tensile modulus, and toughness exhibited by the films increased, while the elongation of the irradiated bio-composite film decreased compared to the control film. The morphology of the irradiated films demonstrated a smoother surface compared to the control and provided surface intermolecular interaction of the neem–seaweed matrix. The film indicated an optimum storage stability under ambient conditions and demonstrated no significant changes in the visual appearance. However, an increase in the moisture content was exhibited by the film, and the hydrophobic properties was retained until nine months of the storage period. The study of the films antimicrobial activities against Staphylococcus aureus (SA), and Bacillus subtilis (BS) indicated improved resistance to bacterial activities after the incorporation of neem leaves extract and gamma irradiation. The fabricated irradiated seaweed–neem bio-composite film could be used as an excellent sustainable packaging material due to its effective storage stability.

In the fast-developing world, the environmental pollution, preservation of renewable and biodegradable resources has motivated researchers to develop novel eco-friendly materials and products based on sustainability principles. In this work, natural sources such as inner banana trunk polymer matrix composites (IBTPMC) and eggshell polymer matrix composites (ESPMC) are prepared by injection molding (IM) and vacuum assisted resin transfer molding (VARTM). The objective is to evaluate feasibility of the materials using IM and VARTM techniques. The specimens were subjected to the mechanical testing for its strength. The tensile modulus for ESPMC composites is 897 MPa compared to IBTPMC only 561 MPa. In izod impact test, IBTPMC shows the highest impact strength of 0.362 J, which is superior then in ESPMC or pure polypropylene (PP). The flexural strength of the pure PP is 58 MPa while for IBTPMC and ESTPMC, both are 42 MPa and 53 MPa respectively. Wear rate for ESPCM has reduced by 64–66% by increasing the load. Wear rate for IBTPCM shows increased by 13 times the initial wear as loading increases and reduced from 1–1.3 times as sliding distance increases. It shows that the IBTPMC fibre ruptured easily leading to higher wear in comparison to ESPCM structure due to fibre wetting properties and distribution of fibre in the matric interface. Coefficient of friction (COF) for IBTPMC shows increment from 0.38 to 0.55. While the COF for ESPCM increased from 0.28 to 0.35. Finally, Scanning Electron Microscope (SEM) to analyze the structure of the fractured surfaces was carried out.

A comparison of d2 law and penetration length of biofuels with Jet–A through the incorporation of fuel properties and actual combustor inlet data at various flight trajectories is presented. This study aims to identify fuel properties and flight operating conditions that most influence droplet characteristics accurately. The study comprises two phases involving a simulation using GSP to predict combustor inlet data for the respective flight operating conditions and a simulation using ANSYS Fluent V18.1 to obtain combustion characteristics of biofuels and Jet–A. The biofuels chosen in this study are Jatropha Bio-synthetic Paraffinic Kerosene (JSPK) and Camelina Bio-synthetic Paraffinic Kerosene (CSPK), evaluated as pure (100%) and blend (50%) with Jet–A. Thrust specific fuel consumption (TSFC) of biofuels is improved due to lower fuel consumed by the engine. The d2 law curve shows a heat-up period that takes place at the early stage of the combustion process. The penetration length of the fuels is shorter at take-off. Combusting biofuels reduce combustion temperature and the penetration length of the droplet.

This chapter covers the key issues on the understanding of the behaviour of composite materials at elevated temperature and in fire environment. Fire is a serious safety issue in the industries that utilising composite materials such as in aerospace, marine, civil and transport as well as in the oil and gas industry. The fire reaction, as well as fire resistance properties of polymer composite materials, are discussed concisely in this chapter. The thermal response and the effects of simultaneous loading (tension and compression) in fire are also adequately explained. The residual properties of composite materials after fire, as well as a brief introduction into fire protection subject for composite structural materials, are also included in the chapter. Finally, the conclusions are summarised at the end of the chapter, and the future direction in the area of fire structural behaviour of composite materials are identified and elucidated.