Composites For Industrial Applications Research Articles

Preparation and characterization of novel bio‐based polyamide 5.6 composites as sustainable alternatives to petroleum‐derived polyamide 6.6

AbstractIn the pursuit of sustainable solutions, this study investigates the potential of bio‐based polyamide 5.6 (PA56) as a promising alternative to petroleum‐derived polyamide 6.6 (PA66). Novel composites of PA56 and PA66 were prepared with the incorporation of glass fibers and flame retardant additives by twin screw extruder. Subsequently, these composites were subjected to comprehensive characterization to determine their performance. The physical, mechanical, rheological, thermal, and flammability properties of PA56 composites were investigated and compared with those of PA66 composites with the same formulations. This article aims to unveil the remarkable potential of bio‐based PA56 composites in industrial applications. The results showed that bio‐based PA56 exhibits comparable, and in some cases superior, performance to PA66 while offering the added advantage of environmental sustainability. The findings suggest that bio‐based polyamide 5.6 can serve as a sustainable alternative to petroleum‐derived polyamide 6.6, contributing to a greener future in industrial applications.Highlights Bio‐based PA56 exhibits comparable properties to petroleum‐derived PA66. Incorporation of glass fibers and flame retardants enhances the properties of PA56. Findings propose PA56 as a sustainable alternative to PA66 in various applications.

Mechanical properties and design of hybrid composites of carbon and jute fibers with polypropylene

Natural fibers have both environmentally friendly and ecological advantages in the fiber material industry. Improving the mechanical properties and durability of natural fiber composites is an important research approach. As one of the representatives of synthetic fibers, carbon fiber has excellent mechanical properties and chemical stability, but its high cost and low toughness limit further application. Combining environmentally friendly, low-cost natural fibers with carbon fibers can broaden the development of natural fiber-reinforced composites in industrial applications. In this paper, the composites made of jute fibers and polypropylene (PP) as well as carbon fibers coupled with KH550 modification were prepared and their properties were investigated. By introducing a macroscopic model similar to the core-shell structure, an environmentally friendly material with better mechanical properties was achieved, with carbon fiber woven fabric serving as the shell and jute fiber mat as the core. The results show that a low-cost hybrid composite was successfully prepared by using a small amount of carbon fiber woven fabric instead of jute fiber mat, and the tensile, flexural and impact properties of the composites were improved by 488.27%, 70.75% and 463.39%, respectively, compared with those of the pure jute fibers composites. This study provides a rapid and reliable approach to improve the mechanical properties of the natural fiber composites.

Unveiling the dual role and regulatory mechanism of stearic acid in enhancing interface compatibility in high-filled coal gangue-polyethylene composites

Stearic acid (SA) modification of coal gangue (CG) presents a promising avenue for producing high-filled, high-performance composites. This study aimed to elucidate the influence of SA on composite interfacial compatibility and its control mechanism. The composite, consisting of polyethylene (PE) and SA-modified CG (80 wt%), was fabricated via hot-pressing to establish the correlation between SA quantity and composite properties, uncovering SA's role in property enhancement and interface formation mechanism. Findings revealed the dual role of SA in composite compatibility. At lower SA concentrations (≤1.0 %), it facilitated enhanced interfacial compatibility. However, this effect plateaued and declined at higher SA concentrations (>1.0 %). This decline was attributed to SA's lubricating effect, where a high SA content on the CG surface acted more as a lubricant than a component enhancing interfacial properties. Moreover, sustainability analyses highlighted the simplicity, environmental friendliness, and economic viability of the process for producing high-filled CG composites using SA-modified CG. This study provides both scientific insight and practical guidance for leveraging high-filled CG composites in industrial applications.

Bending responses of self-shaping wood bilayers: comparison between adsorption and desorption processes

Inspired by biological materials, the self-shaping wood composites induced by relative humidity (RH) have been investigated over the last decade. In this study, a wood bilayer was fabricated by assembling two layers with perpendicular fiber orientation in a series of thickness ratios and initial moisture contents (iMC). The self-shaping response of the wood bilayer was explored as a function of its configuration, and the discrepancies between moisture adsorption and desorption processes were clarified. Higher iMC limited the evolution of curvature. During both the adsorption and desorption processes, a reversed bending response was observed, and there was a hysteretic bending behavior between them. Repeatable bending was achieved during the cyclic ad/desorption process, and a larger hysteresis loop was observed at a lower thickness ratio. Finite-element analysis showed that the maximum stress occurred at the interface between the active and passive layers, and larger thickness ratios had lower maximum stress. In addition, the bilayer composed of a 200 μm passive layer and a 400 μm active layer with 0.6% iMC was found to be the most sensitive to RH change. The results of this study elucidate the moisture-dependent bending response of wood bilayers and provide the possibility of precisely controlling the curvature of self-shaping wood composites in industrial applications.

Ultrasonic welding of fiber reinforced vitrimer composites

In this investigation, we present an exciting discovery that glass and carbon fiber-reinforced vitrimer composites (vGFRC and vCFRC) can be ultrasonically welded. The study shows that applying mechanical vibrational energy can facilitate dynamic bond exchange reactions in transesterification vitrimer composites, resulting in good weldability and mechanical properties. The results show that ultrasonic welding is potentially a practical and cost-effective option for assembling complex or large parts compared to oven curing, as it requires significantly less energy and time. Moreover, the healing properties of vitrimers make them a promising material for repeated processing and welding at the same spot. The study provides insight into the mechanisms of ultrasonic welding of vitrimers comprising bond exchange reactions and polymer chain diffusion at the surfaces. The composites with carbon fiber show better performance properties during welding compared to glass fiber-embedded composites. Lap shear failure surfaces show mostly cohesive failure. Additionally, the weld strength is also influenced by the catalyst concentration in the vitrimer composites. This investigation opens new avenues for vitrimer composites in industrial applications requiring rapid and energy-efficient welding.

Bismuthene nanosheets prepared by an environmentally friendly method and their thermoelectric epoxy nanocomposites

Theoretical research has predicted high thermoelectric performance for bismuthene nanosheets, but it is a great challenge to prepare these nanosheets due to low efficiency and intensive oxidation. We herein report an efficient, environmentally friendly preparation method for bismuthene nanosheets, each being 1–1.5 nm thick in average, through mechanochemical treatment with an ethanol system. The system was found to prevent adverse oxidation in comparison with a pure water system. Although neither the oxidation reactions nor the exfoliation could significantly change the Seebeck coefficient of bismuthene nanosheets, their power factor was measured as 155.6 ± 15.4 μW·m-1K-2. An epoxy nanocomposite was prepared containing 99 vol% of bismuthene nanosheets, to create a thermoelectric generator. It converted a temperature gradient of 11°C generated by human body into an electrical output of 18.62 nW. Our mechanochemical exfoliation method for the preparation of low-oxidation bismuth nanosheets offers insights for large-scale fabrication of nanosheets and their composites for industrial applications. It advances the field of thermoelectric nanocomposites.

Recycling waste polyurethane from the refrigeration industry as filler in SBR/NR composites for industrial applications

AbstractThe refrigeration industry produces millions of tons of waste polyurethane (PU) every year, which can cause environmental damage and human health problems. This article analyzes the use of waste PU as filler in composites made of styrene butadiene rubber (SBR) and natural rubber (NR) to produce shoe soles. The interfacial interaction of said filler was evaluated by the Flory–Rehner method (swelling) using the equation developed by Lorenz–Park. The results of this evaluation were later compared with those obtained by the Mooney–Rivlin method using the data from stress–strain tests. According to the results of the tensile strength tests, the composites filled with waste PU present stress–strain curves that are like those of metallic materials that have low elastic strength but high plastic strength. Using the Lorenz–Park equation, the filled composites examined in this study exhibited values above 0.7, which means a strong filler–rubber interaction. Scanning Electron Microscopy and Fourier‐Transform Infrared Spectroscopy were used to investigate the morphology of the composites in detail.

From adaptive plant materials toward hygro-actuated wooden building systems: A review

Hygroscopic movement is widely observed in plant and is a self-shaping response that does not require an external force or energy. It is interpreted as the adaptation capability of plants to their environments. The key to the hygroscopic movement is the structural arrangement of the plant tissues, typically in a bi-layer configuration. Herein, the transfer from the principles of hygroscopic movement of plants to biomimetic wooden building systems is reviewed. Biomimetic wooden building systems have been generated from the centimeter- to meter-scale, such as “silenced tower”, smart ventilations, and self-propelling robots. However, achieving programmed and precise shape changes on an appropriate time scale is challenging. For example, almost all currently available hygro-actuated composites are inferior to the pine cone scales, which can be conducted many opening-closing cycles without fatigue failure. Therefore, an optimized configuration of the biomimetic composites is necessary to improve their durability by fully understanding of the plants structures. Enhancing the applicability among the common wood species worldwide is also challenging when promoting hygro-actuated composites in industrial applications. Furthermore, finding an appropriate trade-off between response time and mechanical stability of the composites is essential when reacting to changing environmental stimuli. Over-all, the cross-disciplinary studies between plant biology and engineering provide solutions for fabricating sustainable and energy-saving smart building systems.

Experimental mechanics analysis of recycled polypropylene-cotton composites for commercial applications

The sustainable processing of recycled products requires veritable testing during quality control for commercial application. In this research work, mechanical (ASTM D3039), compression (ASTM D5467) and impact (ASTM A370) are utilized to observe the usability, diversity, and suitability of the developed polypropylene-postconsumer cotton fibers (PP-PCCF) composites for industrial applications. The cotton waste was ground using a grinding machine. The ground fibers were introduced to manufacture composites from 0 to 40% fiber loading variations. The fine cotton fibers and synthesized composites were characterized by scanning electron microscope before and after mechanical testing. The fiber length, diameter and area were in the range of 2.5 mm–5.5 mm, 12.5 μm–22 μm and 200.15 μm2–250.50 μm2, respectively. The engineering and design values were tensile strength (31.16 MPa–22.77 MPa), breaking strength (26.69 MPa–22.77 MPa), modulus of elasticity (2223.79 MPa–2770.77 MPa), and extension (17.48–3.21). Similarly, flexural strength, modulus, energy, and fracture force are also enhanced with an increase in fiber loading. The impact energies of pure polypropylene and PP-PCCF composites (with 10, 30, and 40% PCCF contents) were 50 kJ/m2, 48 kJ/m2, 43 kJ/m2, and 58 kJ/m2. The micrographs of PP-PCCF composites prove that the density of voids is enhanced with an increase in fiber contents. The PP-PCCF composites with 0%–30% fiber loadings showed minimum defects and were observed to be suitable for structural applications. On the other hand, the PP-PCCF composites with 30%–40% fiber loading are acceptable for environmental applications.

Effect of titanium oxide, alumina oxide and silicon carbide on mechanical properties and thermal properties of reinforced nylon composites for industrial applications

Effect of titanium oxide, alumina oxide and silicon carbide on mechanical properties and thermal properties of reinforced nylon composites for industrial applications

Effect of olive pomace particles content on mode I and mode II delamination fracture of S‐glass fiber reinforced composites

AbstractThis work aims to investigate the effect of micro‐sized olive pomace (OP) particle incorporation on the mode I and mode II delamination fractures of glass fiber reinforced polymer composites. In this way, it is possible to recycle the natural OP materials and benefit from the development of high performance engineering polymer matrix composites in industrial applications as well as producing low cost composite. For this purpose, six different OP weight ratios (0%, 0.5%, 1%, 5%, 10%, and 15%) were used for modification of matrix resin of composite samples. Double‐cantilever beam, end‐notched flexure tests were conducted according to ASTM standards for evaluation of mode I and mode II fracture delamination toughness properties of the OP filled composites. Scanning electron microscopy photos were taken from the fractured test samples after the mode I and II interlaminar fracture tests to characterize their morphological nature. The results showed that the mode I and mode II inter‐laminar fracture toughness values reached the highest value at OP content of 5 wt% with enhancement of 13.8% and 60.4%, respectively.

Surface Treatments of Coffee Husk Fiber Waste for Effective Incorporation into Polymer Biocomposites.

Natural lignocellulose fibers have been extensively investigated and applied as a reinforcement of polymer composites in industrial applications from food packing to automotive parts. Among the advantages of natural fibers stands their relatively low cost and sustainable characteristics. These are accentuated in the case of residual fibers such as those obtained from coffee husks, an agribusiness waste, usually burnt or disposed into the environment. As composite reinforcement, hydrophilic natural fibers display adhesion problems to the most hydrophobic polymer matrices. This adhesion might be improved with distinct types of fibers surface treatments. In the present work, the effectiveness of three surface treatments applied to coffee husk fiber wastes (CHFW) were investigated, aiming to improve the tensile performance of castor oil-based polyurethane (COPU) biocomposites. The effects of treatments associated with (i) chemical with sodium hydroxide, (ii) physical by temperature and pressure and hydrothermic treatment, and (iii) biological by fermentation with Phanerochaete Chrysosporium fungus were evaluated by means of Fourier transformed infrared spectroscopy, X-ray diffraction, thermal analyses and morphology by scanning electron microscopy for different concentration of NaOH, different hydrothermic times at 121 °C/98 kPa and exposition to P. chrysosporium. The most effective treatment was the hydrothermal one at 121 °C and 98.06 kPa for 30 min. Preliminary tensile tests were performed in COPU biocomposites reinforced with 20% CHFWs subjected to the optimized conditions for each distinct type of treatment. The results indicated that the hydrothermal treatment promoted significant enhancement in the fiber/matrix interfacial bond, increasing the tensile strength up to 60% compared to COPU reinforced with in natura CHFWs fibers. It is important to mention that these composites can be applied as plastic wood for household items’ internal parts and in the automobile industry.

Self‐healing in high impact polystyrene (HIPS) composites via embedded non‐toxic solvent‐filled microcapsules

AbstractPolymer composites are widely used in many industries due to their desirable, and commonly superior properties. However, the replacement of damaged composite materials can be very costly and time‐consuming, motivating the development of self‐healing composites that recover their properties after a damage event. This work demonstrates the microcapsule‐based self‐healing of compression molded thermoplastic high impact polystyrene (HIPS) composites using a non‐toxic and environmentally friendly solvent, ethyl phenylacetate (EPA). EPA is incorporated within double‐walled polyurethane‐poly(urea‐formaldehyde) (PU/UF) microcapsules which are then integrated within the HIPS specimens. Flexure and fracture behavior, with and without microcapsules, is used to investigate the microcapsules' impact on composite physical properties and to determine the composite's self‐healing efficiency (up to 64%) after healing in response to fracture. Overall, this work demonstrates the inclusion of self‐healing properties in a commercially important polymer material with a non‐toxic and environmentally friendly solvent and motivates further development of thermoplastic self‐healing composites for industrial applications.

Effects of CVI SiC amount and deposition rates on properties of SiCf/SiC composites fabricated by hybrid chemical vapor infiltration (CVI) and precursor infiltration and pyrolysis (PIP) routes

The SiCf/SiC composites have been manufactured by a hybrid route combining chemical vapor infiltration (CVI) and precursor infiltration and pyrolysis (PIP) techniques. A relatively low deposition rate of CVI SiC matrix is favored ascribing to that its rapid deposition tends to cause a ‘surface sealing’ effect, which generates plenty of closed pores and severely damages the microstructural homogeneity of final composites. For a given fiber preform, there exists an optimized value of CVI SiC matrix to be introduced, at which the flexural strength of resultant composites reaches a peak value, which is almost twice of that for composites manufactured from the single PIP or CVI route. Further, this optimized CVI SiC amount is unveiled to be determined by a critical thickness t0, which relates to the average fiber distance in fiber preforms. While the deposited SiC thickness on fibers exceeds t0, closed pores will be generated, hence damaging the microstructural homogeneity of final composites. By applying an optimized CVI SiC deposition rate and amount, the prepared SiCf/SiC composites exhibit increased densities, reduced porosity, superior mechanical properties, increased microstructural homogeneity and thus reduced mechanical property deviations, suggesting a hybrid CVI and PIP route is a promising technique to manufacture SiCf/SiC composites for industrial applications.

Fire Retardancy, Thermal Stability and Irradiation Studies of Modified Poly (Vinyl Chloride) composites for Industrial Applications

Poly(vinyl chloride) (PVC)composites were prepared by compounding different concentrations of antimony trioxide Sb2O3 (ATO) and Organo-modified montmorillonite clay (OMMT) as fillers under the effect of gamma irradiation in order to improve its fire retardancy properties. The fire retardacny of the prepared PVC composites were evaluated by measuring ofthe limiting oxygen index (LOI). The mechanical properties, thermal stability by using of the thermogravimetric analysis (TGA) and the electrical conductivity were also investigated. The results indicated that the addition of ATO alone up to 3 phr or the mixture of ATO 1.5 phr/ OMMT 1.5 phr enhances the fire retardancy properties, accompanied with a decrease in the mechanical properties, without effective change in the thermal and electrical conductivity. Moreover, it was found that the mechanical properties and the gel content of the prepared PVC composites were enhanced accompanied with a decreasing in the swelling ratio, as a function of the irradiation with gamma rays up to 50 kGy.

Developing high performance PA 11/cellulose nanocomposites for industrial-scale melt processing

This study presents methods of developing thermally stable polyamide 11 (PA 11), cellulose nanocrystal (CNCs) composites able to withstand high temperature processing for high performance applications. Thus far, it has been difficult to use cellulose-based composites in industrial applications due to the high temperatures at which the materials would need to be processed. Sulfated CNCs (S–CNCs), the most commercially available CNCs, perform the poorest with respect to being thermally stable at high temperatures. Direct mixing techniques typically used to make these nanocomposites at a lab-scale, even at low concentrations of CNCs, have resulted in poor dispersion and thermal stability of CNCs. However, this paper offers industrially viable methods of fabricating composites that shield these S–CNCs from excessive thermal degradation during processing. We set out to determine the effect of pre-mixing CNCs and the polymer to obtain homogeneous and thermally stable nanocomposites for high temperature processing methods such as compression molding and injection molding. For the PA 11/CNC composites, fabrication through both milling and compounding resulted in reinforcement of the polymer with increased storage modulus in the rubbery plateau, and increased Young's modulus while preserving the toughness of PA 11. Furthermore, the milled samples showed higher stiffness than the compounded samples and surface charge density of the CNCs played a great role in the mechanical properties of the composites as it directly correlates with how well dispersed the composites were. Overall, this work shows the potential of pre-mixing methods to obtain high performance nanocellulose based composites through industrial manufacturing processes.

A Review on Bio Composites in Industrial Applications

Today biological materials science is one of the most rapidly growing areas. It mainly focuses on natural materials, synthetic materials in biomedical applications and bio inspired materials. Composites are developed based on the requirement. In India natural fibres and agricultural waste are available in large. Hence, today the focus is to make progress in composites to explore value-added application possibilities. This paper presents a review on development of different types of bio composites in variety of applications. It also includes coverage of recent publications in the literature pertaining to bio composite focusing on improvement in their mechanical properties. This paper outlines the success of bio composites in practical application, which has led to improvement in strength, shape, function, and behaviour of material.

SLIDING WEAR PERFORMANCE OF NANO CUO PARTICLES - SHORT SISAL FIBERS - POLYAMIDE 66 HYBRID COMPOSITES

Polymers and their composites are being increasingly employed in view of their good strengths and corrosion resistance. The features that make the polymer composites in industrial applications are the opportunities to tailor their properties with special fillers. For instance, short carbon and glass fibers have been successfully employed to improve the strength and therefore the load carrying capacity of polyamide composites can also be improved Optimization of parameters is an important in the tribological process. Response surface methodology (RSM) based optimal parameter analysis was performed to investigate the change of responses like wear rate (WR) and coefficient of friction (COF) with the change of input parameters to determine optimum setting of process parameters such as normal force, sliding velocity and reinforcement for achieving minimum WR and COF. The regression model generates the response surfaces. The present study is to optimize the parameter setting for combined responses.

Analysis on effect of electroless coated SiCp on mechanical properties of polymer matrix composites

ABSTRACTThe versatility of polymer matrix composites in industrial applications has gained reputation and adaptability among advanced materials. Still, treatment of reinforcement for these composites has emerged as a vital domain to be explored. With a continuance to this fact, the present paper aims to analyze the effect of reinforced electroless coated silicon carbide particulates on mechanical properties of composites. The composite is developed using epoxy polymer as matrix and glass fibers as primary reinforcement. The electroless coated and uncoated silicon carbide particulates were used as secondary reinforcement. The phase identification of copper on secondary reinforcement was identified using X-ray powder diffraction technique. Fracture analysis during tensile testing and bonding behavior between matrix and reinforcement is examined using field emission scanning electron microscopy with energy dispersive spectroscopy. The presence of copper particles on secondary reinforcement results in improved interfacial bonding and resistance against fracture during loading.

Natural fiber reinforced polymer composites in industrial applications: feasibility of date palm fibers for sustainable automotive industry

Proper utilization of the available natural resources and wastes became crucial for developing sustainability in industry. In this work, the feasibility of using the date palm fibers in the natural fiber reinforced polymer composites (NFC) for automotive industry was reported. Moreover, this work identifies a gap in the way of evaluating NFC relative to comprehensive desired criteria. This gap leads to disregard potential natural fiber types in industrial applications and keep it no more than an environmental waste problem. Here, criteria that affect the NFC were categorized and classified into levels. Governing criteria were suggested, collected and tabulated according to each level. To ensure the potential and competitiveness of the date palm fiber (DPF) in developing sustainability of the automotive industry, several comparisons between DPF and other fiber types commonly used in this industry were carried out. In most comparisons, DPF was the best selected fiber among all other types. DPF was the best regarding specific Young's modulus to cost ratio criterion. Technical properties and performance, environmental, economical, and societal aspects strongly contribute toward adopting DPF into the automotive sector to improve its sustainability and productivity. Furthermore, this adoption has a significant environmental influence throughout achieving an efficient sustainable waste management practice.