Exploration of Tensile, Flexural and Chemical Inertness Properties of Sisal Fibre Reinforced Polymer Composites-Surface Analysis

Our Experimentation finds, reaction of fibre external analysis on tensile, flexural and chemical resistance properties were studied for sisal fibre reinforced composites. Fibre surface analysis has done to produce link between fibre and the matrix to improve the mechanical properties. Fibre surface analysis were done by boiled the sisal fibres in different % of NaOH and treated the fibres in different % of NaOH, treated in acetic acid and methanol. Polyester resin have used as the matrix for preparing the composites and these properties for Natural sisal fibre reinforced composites were also studied. From the results it was observed that 25% NaOH boiled sisal fibre reinforced composites have higher tensile, flexural properties than other composites. Natural sisal fibre composites show fewer properties than treated composites. Chemical inertness properties indicate that all sisal fibre reinforced composites are resistance to all chemical agents except carbon tetra chloride.

Effect of conditions and parameters of drawing on strength and surface condition of basalt continuous fibers

Basalt continuous fibers are used in the development of new composite materials. The influence of various factors on the strength and formation of the surface microstructure of basalt continuous fibers is considered. An experimental determination of tensile strength was performed and the surface condition of continuous andesite-basalt fibers with a diameter of 8 to 10 μm fibers was investigated. It is established that the strength of fibers, among other factors, is influenced by the conditions of their production, which are determined by the drawing parameters: the production temperature, the level of melt in the feeder and the winding speed. The effect of production temperature on the strength of the fibers was the greatest. It was found that the fibers obtained at a production temperature of 1450 °C had a strength of 24—28% greater than that of the fibers obtained at a production temperature of 1400 °C. The separate influence of other parameters of drawing, the level of melt in the feeder and the winding speed on the strength of the fibers is less significant. A qualitative relationship between the state of the surface of the fibers and the conditions of their production at different parameters of formation. The greatest influence on the change in the state of the surface of the fibers has the temperature of fiber production. It is established that the surface of the fibers obtained at a production temperature of 1450 °C is more homogeneous with a small number of visible defects. On the other hand, on the surface of the fibers, which are obtained at a production temperature of 1400 ºC, there is a large number of defects. There is also an increase in the defect of the surface of the fibers, which are obtained at low levels of melt in the feeder and the winding speed. Keywords: continuous fibre, surface structure, strength, cooling rate, production temperature, winding speed, melt level in the feeder.

Effect of Hemp Fibre Surface Treatment on the Fibre-Matrix Interface and the Influence of Cellulose, Hemicellulose, and Lignin Contents on Composite Strength Properties

Natural fibres have recently become an attractive alternative to synthetic fibres in the implementation of polymer composite structures. Inherent flaws within natural fibres in terms of their constituent contents (hemicellulose, cellulose, and lignin) reduce the compatibility of these fibres with polymer matrices. In this study, the effects of chemical treatments on hemp fibres and the resulted polyester matrix composite are investigated. The fibres were treated with alkali (0–10% NaOH), acetyl, and silane chemicals. Long unidirectional fibre composites were prepared by vacuum-assisted resin transfer moulding (VARTM) process. Thermal properties of the fibres were tested using differential scanning calorimetry (DSC) analyses. The mechanical properties of the composite samples were tested using compression and bending tests. Failure analysis of tested composites was undertaken through Optical Microscope (OM) and Scanning Electron Microscope (SEM). The results showed that the treatments of the 4% NaOH reduced interfacial bonding strength and decreased composite properties compared to untreated samples. At higher concentrations (6–10% NaOH), the mechanical properties of the composites increased as a result of greater interfacial bonding. Different trends were observed in the case of alkalised fibres that were further treated with acetyl and silane treatments. It was observed that the treated fibres effectively improved the bonding properties of composites and was in agreement with the micrographs.

Mechanical Properties, Surface Assessment, and Structural Analysis of Functionalized CFRPs after Accelerated Weathering

The present study focuses on the effect of two novel carbon fibre surface treatments, electropolymerisation of methacrylic acid and air pressure plasma, on the mechanical properties and structural integrity of carbon-fibre-reinforced composites under operational conditions. Extensive mechanical testing was applied, both in nano- and macro-scale, to assess the performance of the composites and the interphase properties after ultraviolet/humidity weathering. The results of the mechanical assessment are supported by structure, surface, and chemistry examination in order to reveal the failure mechanism of the composites. Composites with the electropolymerisation treatment exhibited an increase of 11.8% in interlaminar shear strength, while APP treatment improved the property of 23.9%, rendering both surface treatments effective in increasing the fibre-matrix adhesion. Finally, it was proven that the developed composites can withstand operational conditions in the long term, rendering them suitable for a wide variety of structural and engineering applications.

Gold Nanoparticles: A Novel Dye for Synthetic Fabrics

<p>Fabric has always been prominent throughout history. In the last 70 years new synthetic fabrics have been developed which mimic the natural fibres but have increased strength, durability and stretchability. Common fibres include Polyester, Nylon and Lycra(R). These fibres can be blended to incorporate the properties of both the individual fibre types. Gold nanoparticles have been found to give the stable deep red colour found in stained glass but the science was not understood until the quantum mechanical work of Mie in 1908 on the interaction of electromagnetic radiation (visible light) with fine particles of matter. It is proposed that gold nanoparticles can be used as stable colourants bound to synthetic fibres and other textiles due to its chemical unreactivity. The most common formation method is the use of a reductant such as poly(ethylene imine), sodium citrate or tannic acid. This thesis reports the research and development of new, novel hybrid materials created by combining the interesting properties of both the synthetic fabrics and gold nanoparticles. Twenty five different methods (broken down into four general categories - pre-made colloids, in-situ reduction, use of external reductant after uptake of gold solution and growth of seed particles) were attempted resulting in fabrics that were a variety of shades and colours including pink, purple, tan and gold. The synthetic fabric-gold nanoparticle hybrid samples were analysed by scanning electron microscopy, energy dispersive spectroscopy, infrared spectroscopy, ultraviolet/visible reflectance spectroscopy, x-ray photoelectron spectroscopy, fluorescence spectroscopy and ColourQuest measurements. A sample was also subjected to industry standard "abrasion" and colourfastness tests in which it gained the highest mark possible, showing no staining of other fabrics under dry rub conditions. Atomic absorption measurements were performed on solutions after the fabric was removed in order to confirm the amount of gold uptake by the fabric samples. Analysis showed that a range of nanoparticle sizes and shapes were produced which influenced the visual colour of the fabric. The purple samples produced are caused by small particles (<100nm) that have aggregated together. Samples that appear tan or gold in colour have mainly large particles (>500nm) that are either made up of small spheres fused together or are large plates (trigonal, hexagonal); therefore, Mie's laws do not appear to apply. Light coloured samples generally have a few small particles (<100nm) that are spaced out over the fibre surface.</p>

Gold Nanoparticles: A Novel Dye for Synthetic Fabrics

<p>Fabric has always been prominent throughout history. In the last 70 years new synthetic fabrics have been developed which mimic the natural fibres but have increased strength, durability and stretchability. Common fibres include Polyester, Nylon and Lycra(R). These fibres can be blended to incorporate the properties of both the individual fibre types. Gold nanoparticles have been found to give the stable deep red colour found in stained glass but the science was not understood until the quantum mechanical work of Mie in 1908 on the interaction of electromagnetic radiation (visible light) with fine particles of matter. It is proposed that gold nanoparticles can be used as stable colourants bound to synthetic fibres and other textiles due to its chemical unreactivity. The most common formation method is the use of a reductant such as poly(ethylene imine), sodium citrate or tannic acid. This thesis reports the research and development of new, novel hybrid materials created by combining the interesting properties of both the synthetic fabrics and gold nanoparticles. Twenty five different methods (broken down into four general categories - pre-made colloids, in-situ reduction, use of external reductant after uptake of gold solution and growth of seed particles) were attempted resulting in fabrics that were a variety of shades and colours including pink, purple, tan and gold. The synthetic fabric-gold nanoparticle hybrid samples were analysed by scanning electron microscopy, energy dispersive spectroscopy, infrared spectroscopy, ultraviolet/visible reflectance spectroscopy, x-ray photoelectron spectroscopy, fluorescence spectroscopy and ColourQuest measurements. A sample was also subjected to industry standard "abrasion" and colourfastness tests in which it gained the highest mark possible, showing no staining of other fabrics under dry rub conditions. Atomic absorption measurements were performed on solutions after the fabric was removed in order to confirm the amount of gold uptake by the fabric samples. Analysis showed that a range of nanoparticle sizes and shapes were produced which influenced the visual colour of the fabric. The purple samples produced are caused by small particles (<100nm) that have aggregated together. Samples that appear tan or gold in colour have mainly large particles (>500nm) that are either made up of small spheres fused together or are large plates (trigonal, hexagonal); therefore, Mie's laws do not appear to apply. Light coloured samples generally have a few small particles (<100nm) that are spaced out over the fibre surface.</p>

Effect of Fibre Surface Treatment and Nanofiller Addition on the Mechanical Properties of Flax/PLA Fibre Reinforced Epoxy Hybrid Nanocomposite

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 effect of fibre surface treatment and coupling agents to improve the performance of natural fibres in PLA composites

This paper describes work carried out to assess the effect of fibre treatments and coupling agent on the mechanical performance of PLA composites reinforced with 20 wt% fibre. The chemically-treated harakeke and hemp fibres used to produce fibre mats. Maleic anhydride (MA) grafted PLA (MA-g-PLA) was used as a coupling agent. Composites with fibre treated with silane and dicumyl peroxide (DCP) and composites using MA-g-PLA were characterised by swelling testing, scanning electron microscopy (SEM), tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). It was found that the interfacial bonding for composites with fibres treated using silane and peroxide and composites coupled with MA-g-PLA noticeably improved supported by lower swelling indices, higher tensile strengths and lower tan δ compared to those composites with fibres treated using alkali only, with the highest tensile strength of about 11% higher obtained from composites treated with MA-g-PLA followed by silane and then peroxide. However, using silane, peroxide and MA-g-PLA as additional composite treatments increased significantly the composite failure strain by up 11, 19 and 30%, respectively for harakeke composites and by 13, 24 and 30%, respectively for hemp composites.

Locust bean gum adsorption onto softwood kraft pulp fibres: isotherms, kinetics and paper strength

The adsorption of locust bean gum (LBG) onto Northern Bleached Softwood Kraft (NBSK) pulp improved paper tensile and burst strength and lowered refining energy by strengthening inter-fibre bonding. Adsorption kinetics and isotherms were investigated to develop a fundamental understanding of the adsorption mechanism. The adsorption rate followed pseudo-second-order kinetics and the activation energy was 99.34 kJ·mol−1, suggesting chemisorption. The adsorption rate constant increased rapidly with temperature from 25 to 45 °C (k = 1.93 to 24.03 g·mg−1·min−1), but the amount adsorbed at equilibrium decreased (qe = 1.91 to 0.48 mg·g−1 o.d. fibre). LBG adsorption to NBSK at 25 °C was consistent with the Langmuir adsorption model for LBG < 2.1 wt% of o.d. fibre, suggesting reversible, homogenous adsorption to a finite number of sites on the fibre surface. Refining to 3000 rev increased the heterogeneity of the NBSK pulp surface leading to multi-layer Freundlich adsorption with adsorption constant n = 5.00, and the equilibrium constant Kf = 2.57 mg·g−1·(mg·L−1)−1/n at 25 °C. Favorable adsorption conditions for negatively charged LBG were identified: 25 °C for 10 min, low dosage level (< 2 wt%), lightly refined (< 3000 rev) NBSK pulp at low fibre consistency (< 0.5 wt%), high agitation rate (> 150 r.p.m.), acidic or neutral conditions (pH 2–7) without salt addition. Graphic abstract