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This research investigates the manufacturing and characterisation of polyester-based composites reinforced with jute fibres and red mud particulates. The motivation stems from the need for sustainable, high-performance materials for applications in industries, like aerospace and automotive, where resistance to erosion is critical. Jute, a renewable fibre, combined with red mud, an industrial byproduct, offers an eco-friendly alternative to conventional composites. The composites were fabricated using compression moulding with varying red mud contents (10, 20, and 30 wt.%) and a fixed 40 wt.% of jute fibre. Fibre treatments included sodium hydroxide (NaOH) and silane treatments to improve bonding and performance. Erosion tests were performed using an air-jet erosion tester, examining the effects of the red mud content, fibre treatment, and impact angles. Scanning Electron Microscope (SEM) analysis provided insights into the erosion mechanisms. A distinctive reduction in erosion rates at higher impact angles (30°–60°) was observed, attributed to the semi-ductile nature of the composites. The addition of red mud enhanced erosion resistance, although an excess of 30 wt.% reduced resistance due to poor surface bonding. Silane-treated composites showed the lowest erosion rates. This study provides new insights into the interplay among material composition, fibre treatment, and erosion dynamics, contributing to the development of optimised, eco-friendly composite materials. [ABSTRACT FROM AUTHOR]

In this work, alkali-activated composites using electric arc furnace slag (50 wt%) and biomass bottom ash (50 wt%) were manufactured, adding olive-pruning fibres as reinforcement. The objective of adding fibres is to improve the flexural strength of composites, as well as to prevent the expansion of cracks as a result of shrinkage. For this reason, composites reinforced with olive-pruning fibres (0.5–2 wt%) untreated and treated with three different solutions to improve matrix–fibre adhesion were manufactured. Treatments developed over fibres were a 10 wt% Na2SiO3 solution, 3 wt% CaCl2 solution and 5 wt% NaOH solution. Mechanical properties, physical properties, thermal properties and the microstructure of composites by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were studied to demonstrate the improvement. Alkaline treatment degraded fibre surface, increasing the matrix–fibre adhesion, and as a consequence, flexural strength increased up to 20% at 90 days of curing. Optimal results were obtained with composites reinforced with 1 wt% of olive-pruning fibre treated by a 10 wt% Na2SiO3 solution. Higher quantity of olive-pruning fibre leads to local agglomeration, which weakens the matrix–fibre adhesion. The effect on the compressive strength is less evident, since the addition of fibres produces an admissible decrease (between 0 and 9% using 0.5 or 1 wt% of fibres), except in composites that use olive pruning treated with 10 wt% Na2SiO3 solution, where values remain stable, similar or better to control paste. A greater ductility of the matrix in all composites was observed. Furthermore, the alkali-activated cement matrix was bonded to olive-pruning fibre better than untreated fibre, as it is shown in SEM images. Thus, the results showed that olive-pruning fibres could be used as reinforcement in the manufacturing of alkali-activated materials when they are treated with alkali solutions. [ABSTRACT FROM AUTHOR]

Numerous studies demonstrate that the alteration in the fibre surface caused by the alkali treatment enhances the mechanical capabilities. Muntingia calabura is the novel fibre was used in the present study. The present work illustrates the mechanical and characterization of NaOH and KOH treated muntingia calabura fibre reinforced epoxy composites. Muntingia calabura fibre is extracted from the bark of muntingia calabura plant. The collected fibres are treated with 10% alkali solution and then fibre–epoxy composites are fabricated with different fibre loadings, evaluated the mechanical properties of the Muntingia calabura fibre–epoxy composites. The interfacial bonding between the Muntingia calabura fibre and epoxy (LY-5052) observed with the morphological study. Using thermo gravimetric and infrared spectroscopy, the degradation behaviour and thermal stability of the Muntingia calabura fibre composites and the functional chemicals included in them are investigated respectively. The composites exhibit maximum tensile and flexural strengths of 84 MPa and 185 MPa, respectively, at 20 weight percent of the fibre content treated with NaOH. At 15 weight percent of the fibre content treated with NaOH, the composites have a maximum impact strength of 19.5 J/m2. It was found that the thermal stability of fibre composites treated with KOH and NaOH ranged from 250 to 400 degrees Celsius.

The current study reviews the viability of various fibre-polymer composites and treatment techniques along with the intricacy involved in improving the rotational moulding process. It is a method used in the manufacturing of hollow plastic items free from stress. As the rotational moulding process has gained prominence in a variety of crucial applications in recent years, a detailed analysis of this technique is important. For this reason, an exhaustive review of various fibres and polymers used in rotational moulding along with different pre-treatment techniques for improving the processability has been carried out and categorised into three sections. The first section deals with the type of polymers which are used for the process along with their nature and suitability for rotational moulding. The second section deals with the study of different fibres that have been blended with the polymers. The last section of the review discusses the different fibre treatment techniques which can be used to improve polymer-fibre compatibility. From a wide range of polymers used, it has been observed that the ease of processability of linear low-density polyethylene makes it the most suitable grade for rotational moulding. It can also be noticed that artificial fibres provide good mechanical properties compared to natural fibres but being eco-friendly and having low cost, natural fibres are more vital in the application. It is evident from the review that fibre pre-treatment enhances the polymer-fibre compatibility which improves the mechanical properties of the rotationally moulded products. Further, it can be concluded from the literature review that an adequate variety of polymer and fibre along with fibre treatment techniques can make an important contribution to the rotational moulding process. [ABSTRACT FROM AUTHOR]

The efficacy of wood dust fibre treatment on the property of wood dust reinforced recycled polypropylene composite (r-WoPPC) filament was investigated. The wood dust fibre was treated using alkali, silane, and NaOH-silane. The treated wood fibre was incorporated with r-PP using a twin-screw extruder to produce filament. The silane treatment on wood dust fibre enhances interfacial bonding between wood fibre and recycled PP; hence, a filament has the highest wire pull strength, which is 35.2% higher compared to untreated and alkaline-treated wood dust filament. It is because silanol in silane forms a siloxane bond that acts as a coupling agent that improves interfacial bonding between wood dust fibre and recycled PP. The SEM micrograph of the fracture structure reveals that treated silane has strong interfacial bonding between wood dust fibre and recycled PP, having minimal void, gap, and good fibre adhesion. The water absorption test results indicate that filament with treated wood dust absorbs less water than filament with untreated wood because the treatment minimizes the gap between wood fibres and recycled PP. The FTIR analysis identified the presence of silane on the wood dust surface for silane-treated wood dust. The DSC studies suggest that the temperature range 167–170 °C be used in the extrusion machine to produce r-WoPPC filament. As a result, r-WoPPc filaments containing silane-treated wood dust have better mechanical properties and have a greater potential for usage in FDM applications. [ABSTRACT FROM AUTHOR]

The thermal and rheological properties of bio-composite filament materials are crucial characteristics in the development of a bio-composite Fused Deposition Modeling (FDM) filament since the printing mechanism of FDM strongly depends on the heating and extrusion process. The effect of chemical treatment on the thermal and rheological properties was investigated to develop composite filaments for FDM using natural fibres such as sugar palm fibre (SPF). SPF underwent alkaline and silane treatment processes before being reinforced with PLA for improving adhesion and removing impurities. Thermogravimetric Analysis (TGA), Differential Scanning Calorimetric (DSC), and Melt Flow Index (MFI) analyses were conducted to identify the differences in thermal properties. Meanwhile, a rheological test was conducted to investigate the shear stress and its viscosity. The TGA test shows that the SPF/PLA composite treated with NaOH and silane showed good thermal stability at 789.5 °C with 0.4% final residue. The DSC results indicate that the melting temperature of all samples is slightly the same at 155 °C (in the range of 1 °C), showing that the treatment does not interfere with the melting temperature of the SPF/PLA composite. Thus, the untreated SPF/PLA composite showed the highest degradation temperature, which was 383.2 °C. The SPF/PLA composite treated with NaOH and silane demonstrated the highest melt flow index of 17.6 g/min. In conclusion, these findings offer a reference point for determining the filament extrusion and printability of SPF/PLA composite filaments. [ABSTRACT FROM AUTHOR]

Fibres are often used to improve the mechanical properties of foam concrete. However, the poor dispersion of PVA fibres in foam concrete significantly restricts their reinforcement efficiency. Limited studies have been conducted on improving the distribution of PVA fibres in a cementitious matrix, particularly in relation to foam concrete. This is noteworthy because pore structure, which can be significantly influenced by the fibres and fibre treatment agents, is a critical parameter that affects the mechanical properties of foam concrete. Therefore, this study employed polar agents (non-ionic surfactants) to treat the fibre surface, aiming to enhance the distribution and reinforcement efficiency of PVA fibres in foam concrete. In view of safety and feasibility, two non-hazardous polar agents, namely PEG-PPG-PEG (designated as PA A) and Polyoxyethylene (20) cetyl ether (designated as PA B), were used to treat the PVA fibres. The impact of fibre treatments on fibre dispersion and pore structure was investigated, and the compressive strength and flexural behaviour of foam concrete were measured before and after the treatments. PA A was found to be unsuitable for fibre treatment due to its poor bonding with the fibre surface. On the other hand, PA B exhibited good bonding with PVA fibres, resulting in enhanced fibre dispersion and pore structure in the foam concrete. Compared to plain foam concrete, the fibres treated with PA B increased the compressive and flexural strength by 47.4 % and 190.3 %, respectively. Moreover, the treated fibres (by PA B) were observed to improve the 0.8 mm toughness of foam concrete by 27.2 %. • Polar agent A as additives improved mechanical properties of the foam concrete. • Polar agent B exhibited good bonding with PVA fibres. • Polar agent B treatment enhanced fibre dispersion and pore structure in the foam concrete. • Polar agent B treatment improved the fibre reinforcement efficiency on mechanical properties of foam concrete. [ABSTRACT FROM AUTHOR]

In this study, Cashew Nut Shell Liquid (CNSL)-epoxy matrix-based composites reinforced with borassus and tamarind fibres were fabricated using compression moulding technique. Three different types of composites were fabricated, namely Borassus fruit fine fibre/CNSL-epoxy composites (BF composites), Tamarind fibre/CNSL-epoxy composites (TF composites) and Tamarind/Borassus fruit fine fibre CNSL-epoxy hybrid composites (HB composites). In addition, CNSL-epoxy neat polymer was also fabricated for comparison. Physical properties such as micro-hardness, void percentage, and mechanical properties like tensile, flexural, Interlaminar Shear Strength (ILSS), and impact strength were investigated. Scanning Electron Microscope (SEM) was used to study the failure mechanism of the composites. Experimental results indicate that tensile and flexural properties of BF composites were higher when compared to TF and HB composites. Micro-hardness and impact strength of HB composites were better than the others. SEM images indicated better fibre-matrix bonding in BF composites indicating improved resistance to delamination. Thus, borassus and tamarind fibre reinforced CNSL-epoxy composites can be used as an alternative material for light to moderately loaded structural engineering applications.

In recent years, natural fibre cementitious composites (NFCC) have gained popularity worldwide because of their potential application as low-cost construction materials. Despite the wide range of applications for NFCC, their long-term performance, i.e., durability under various exposure conditions, remains an open question. Natural fibres in a cementitious matrix may degrade over time as a result of the alkalinity of the cement matrix. In this study, Ensete ventricosum (Ev) fibre was treated with alkaline (NaOH) and hot-water to increase its resistance to alkaline attack. Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), physical, and mechanical tests were performed on fibre bundles to evaluate the effect of surface treatment on fibre performance. After undergoing 0 and 25 wet-dry cycles, the composites reinforced with raw and treated Ev fibres were tested in a four-point bending configuration. In order to investigate cracking and failure behaviour, Digital Image Correlation and Acoustic Emission techniques were used. Using SEM, the microstructure of the Ev fibres was analysed. Raw Ev fibre reinforced cement composites completely lost their strength and ductility after 25 wet/dry cycles, whereas hot-water and alkali treated Ev fibre composites showed minimal degradation, demonstrating that hot-water and alkali treatment can reduce the degradation of natural fibres in cement-based composites. These findings are promising for the development of an Ev fibre reinforced cement-based green composite. [ABSTRACT FROM AUTHOR]

In this study, Cashew Nut Shell Liquid (CNSL)-epoxy matrix-based composites reinforced with borassus and tamarind fibres were fabricated using compression moulding technique. Three different types of composites were fabricated, namely Borassus fruit fine fibre/CNSL-epoxy composites (BF composites), Tamarind fibre/CNSL-epoxy composites (TF composites) and Tamarind/Borassus fruit fine fibre CNSL-epoxy hybrid composites (HB composites). In addition, CNSL-epoxy neat polymer was also fabricated for comparison. Physical properties such as micro-hardness, void percentage, and mechanical properties like tensile, flexural, Interlaminar Shear Strength (ILSS), and impact strength were investigated. Scanning Electron Microscope (SEM) was used to study the failure mechanism of the composites. Experimental results indicate that tensile and flexural properties of BF composites were higher when compared to TF and HB composites. Micro-hardness and impact strength of HB composites were better than the others. SEM images indicated better fibre-matrix bonding in BF composites indicating improved resistance to delamination. Thus, borassus and tamarind fibre reinforced CNSL-epoxy composites can be used as an alternative material for light to moderately loaded structural engineering applications. [ABSTRACT FROM AUTHOR]

Abstract The paper describes the impact behaviour of hybrid composites made of sugarcane bagasse fibres and disposed rubber particles. The analysis was carried out using a full factorial design (25) on samples subjected to drop-tower testing. The effects of the bagasse fibre treatment, length and weight fraction were considered, as well as the rubber particles size and their amount. Higher weight fractions of coarse rubber particles led to an enhancement of the absorption. Sustained chemical treatments of the bagasse fibres provided an increase of the composites stiffness, reducing therefore the energy absorption. In contrast, higher energy absorption was obtained in composites made with untreated bagasse because of the enhanced fibre pull-out mechanism. [ABSTRACT FROM AUTHOR]

In the case of fire, the carrying capacity of the textile-reinforced-concrete (TRC) depends greatly on the thermomechanical behaviour of the reinforcement textile at elevated temperatures. Carbon textiles are manufactured in industry as commercial products for application in TRC. The treatment of carbon fibres by products of different natures in the manufacturing chain also influences the thermomechanical behaviour and mechanical property evolution as a function of temperature. This paper presents an experimental study on the tensile behaviour of three different continuous carbon textiles subjected to simultaneous mechanical loading and elevated temperatures (varying from 25 °C to 600 °C). The results on three carbon textiles are compared to understand the effect of fibre treatment on the thermomechanical behaviour of carbon textile. The experimental results are used to calibrate a prediction analytical model (Mouritz and Gibson), which can be applied to the thermomechanical estimation of carbon textile under different temperature and mechanical conditions. [ABSTRACT FROM AUTHOR]

• The treatment of sugarcane fibre (sbc) affects most physical and mechanical properties. • Fibre treatment, mainly with stearic acid, leads to better fibre–matrix interfacial adhesion. • Treated fibre composites have lower water absorption, apparent density and porosity. • Treated fibre composites have higher stiffness, strength and toughness than untreated ones. • Higher amount of sbc leads to reduced density, elastic modulus, strength and toughness. • Higher amount of sbc leads to higher water absorption and porosity. This work describes the physical and compressive properties of cement composites reinforced with short bagasse fibres to promote the recycling of sugarcane residues. Stearic acid and castor oil reagents are used as fibre modifiers leading to a hydrophobic character. A 32 factorial Design of Experiment (DoE) is used to evaluate the fibre amount and treatment factors statistically. A reference mortar is made to compare the results. Treated fibre composites achieve higher mechanical properties and lower physical properties. The low amount of fibres leads to superior responses, except for apparent density. A DoE optimisation shows that cementitious composites with 2 wt% of stearic acid-treated fibres achieve optimal mechanical and physical properties. Mechanical responses increase by up to 22.25%, while physical responses reduce by up to 20.46% in relation to the reference mortar. Short fibres treated with stearic acid can improve the physical and mechanical properties of mortars for secondary applications in civil construction. [ABSTRACT FROM AUTHOR]

Abstract: Fully biodegradable composites were developed, possessing prominent mechanical performance and reduced flammability at the same time. The manufactured composites consisted of PLA/TPS biopolymer matrices reinforced with chopped flax fibres. The flammability of the prepared biocomposites was reduced by a newly synthesized multifunctional additive system. Glycerol phosphate (GP), a plasticizer of starch with flame retardant potential, and a novel phosphorous-silane (PSil), applied as a surface treating agent of the reinforcing biofibres, were successfully combined in order to reduce the flammability of the prepared biocomposites. Owing to the beneficial effect of the applied multifunctional additive system, a loading of as low as 10 wt% of ammonium polyphosphate (APP) proved to be sufficient to provide prominent levels of flame retardancy to the composites, i.e. V−0 rating according to UL94, 33 vol% LOI and a 40% reduction of heat emission were achieved. Furthermore, the combined application of the surface treated reinforcing flax fibres and plasticizer in the biodegradable, flame retarded biocomposites resulted in well-balanced strength and stiffness. [Copyright &y& Elsevier]

In this study, carbon/banana fibre hybrid reinforced epoxy composite was prepared and analyzed based on: (1) water absorption and (2) swelling rate, followed by the optimization using the Taguchi method. These samples were prepared using a 2:1 ratio of epoxy and hardener as the matrix and altering the reinforcement hybrid of fibre via the lamination process. The experiment was designed using a Taguchi L9 orthogonal array. Three factors were employed in the analysis: (1) reinforcing layer, (2) fibre treatment, and (3) temperature. The experimental results showed that fibre treatment followed by the number of reinforcement layers were the key performance parameters with the temperature having the least impact. A similar analysis was also obtained using the Taguchi method, showing that both the experimental and theoretical studies were in agreement. The optimization conditions, both for absorption and swelling rates are (1) number of reinforcement layers of 1, (2) fibre treatment of 4%, and (3) temperature of 40 °C, with the condition designated as A1B3C2 in the Taguchi method. [Display omitted] • Production of carbon/banana fibre composite using hand layup lamination method. • Process optimization using experimental and theoretical techniques. • ANOVA, Taguchi design and regression analysis used in the study. • Fibre treatment and the number of layers are influential parameters for the study. [ABSTRACT FROM AUTHOR]

Different chemically treated hemp fibre reinforced unsaturated polyester composites were investigated over a range of fibre content (0–60 wt%). Although Young’s modulus of all the short fibre reinforced unsaturated polyester composites was found to be higher than that of unreinforced unsaturated polyester; however, tensile strength of the composites exceeded that of the unsaturated polyester matrix only for the combined alkali- and silane-treated fibre composites at 40 wt% fibre content. The decrease in tensile strength of the composites could be attributed to stress concentrations caused by the fibres in conjunction with the brittle matrix. Impact strength of all the treated fibre composites was higher than that of the untreated fibre composites at all fibre contents. KIc and GIc of the composites decreased initially and then increased as the fibre content increased because more and more fibres being available to pull-out. The mechanical properties of the composites were increased further due to the alignment of long fibres. [ABSTRACT FROM AUTHOR]

In this study, pitch-based short carbon fibres were treated by both an air oxidation and a cryogenic treatment, thereafter these fibres were incorporated into epoxy matrix for wear investigations. It was found that under an appropriate air oxidative condition, the wear resistance of carbon fibre reinforced epoxy was significantly improved at low contact pressure, whereas that was reduced at high pressures which may due to the damage of fibre mechanical properties after oxidation. On the contrary, carbon fibres preformed better at high sliding pressure after cryogenic treatment. Correlated wear mechanisms were discussed. [Copyright &y& Elsevier]

Pitch-based short carbon fibres were treated by both a gaseous oxidation and a cryogenic treatment approach. It was found by scanning electron microscopy that the fibre surface roughness was increased by various oxidative conditions, whereas the fibre diameter was reduced by the cryogenic treatment. In both cases, appropriate treatments could effectively improve the mechanical properties in their epoxy composites due to the enhanced fibre–matrix interfacial bonding. [Copyright &y& Elsevier]

In the present work, the influence of the fibre treatment on the transverse stiffness of glass/epoxy unidirectional laminates is discussed. The transverse modulus of UD-plates with different fibre treatments was determined by the transverse tension test and by vibration tests with holography and an identification procedure. It will be shown that a significant influence of the fibre treatment (interphase) can be observed if the transverse modulus is determined by tension tests. If the transverse modulus is determined by non-destructive testing with vibration tests, including a mathematical identification procedure, no significant influence of the fibre treatment can be observed. This indicates that the results of transverse tension tests should be used very carfully to describe the influence of the interphase on the transverse modulus of unidirectional reinforced plates. It is recommended to use some additional (non-destructive) testing, e.g. vibration tests. [ABSTRACT FROM AUTHOR]

Natural fibre as a reinforcing agent has been widely used in many industries in this era. However, the reinforcing agent devotes a better strength when embedded with a polymer matrix. Nevertheless, the characteristic of natural fibre and polymer matrix are in contrast, as natural fibre is hydrophilic, while polymer is hydrophobic in nature. Natural fibre is highly hydrophilic due to the presence of a hydroxyl group (-OH), while polymer matrix has an inherent hydrophobic characteristic which repels water. This issue has been fixed by modifying the natural fibre's surface using a chemical treatment combining an alkaline treatment and a silane coupling agent. This modifying process of natural fibre might reduce the attraction of water and moisture content and increase natural fibre surface roughness, which improves the interfacial bonding between these two phases. In this paper, the effect of alkaline and silane treatment has been proven by performing the mechanical test, Scanning Electron Micrograph (SEM), and Fourier Transform Infrared spectrometry (FTIR) to observe the surface structure. The chemical compositions and thermal properties of the composites have been obtained by performing Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) tests. 1.0% silane treatment displayed better strength performance as compared to other composites, which was proven by performing Scanning Electron Micrograph (SEM). The assumption is that by enduring chemical treatment, kenaf fibre composites could develop high performance in industry applications. [ABSTRACT FROM AUTHOR]

In this research NaOH treated date palm fibres were used as reinforcement in phenolic based composites. The composites were prepared by hot press technique and evaluated tensile flexural, structural, thermo gravimetric dynamic mechanical properties. Overall properties of modification/treatment of fibers' surface enhanced, that have been studied as compared to untreated samples. The treated samples of 50% DPF composites showed highest Tensile properties among all composites but flexural properties declined compared to the untreated composites but this decline is very less. Fibre treatment showed declined properties of three point bending of DPF composites. Scanning Electron Microscopy studied the behavior of fibre and matrix bonding before and after treatment. Treated 50% DPF showed better fibre distribution, 60% DPF showed void content however 40%DPF showed poor fibre/matrix interfacial bonding. Thermogravimetric analysis studied the behavior of Treated DPF/Phenolic composites at high temperature, and found thermal stability enhanced because good interfacial bonding. Dynamic mechanical analysis showed that stability at stress of material with temperature and also studied the energy dissipation and internal friction. Treated 50%DPF showed better properties due to the ratio of mixing of fibre/matrix and better interfacial bonding. DPF composite have potential to use for exterior applications and false wall and roof. [ABSTRACT FROM AUTHOR]

Some studies have evaluated the use of Opuntia as reinforcement for polymeric matrices, obtaining good results in energy absorption tests and increasing the tensile elastic modulus. However, no studies focusing on the previous characterisation of the fibres and their treatment to improve compatibility with polymeric matrices have been found. This work analyses the chemical composition of Opuntia maxima (OM) and Opuntia dillenii (OD) cladodes and fibre, studying how different treatments influence it. AOAC 2000 methods were used to determine non-structural components and the Van Soest method was used to estimate structural components. Surface characteristics of the samples were also evaluated by Fourier Transform Infrared Spectroscopy (FTIR). Opuntia fibre presented higher cellulose (50–66%) and lignin (6–14%) content and lower hemicellulose (8–13%) content than Opuntia cladodes (9–14% cellulose, 20–50% hemicellulose, 1–4% lignin). Despite the variability of lignocellulosic materials, OD cladodes treated with water and acetic acid achieved an increase in the structural components. Alkaline fibre treatment removed pectin and hemicellulose from the fibre surface, slightly increasing the cellulose content. Future research should evaluate whether the treated Opuntia fibre can improve the mechanical properties of reinforced polymer. [ABSTRACT FROM AUTHOR]