Natural Fiber Reinforced Polymer Composites Research Articles

Natural Fibre Reinforced Polymer Composite (NFRPC) from Waste Polypropylene Filled with Coconut Flour

Abstract:-The authors prepared a biodegradable composite using waste polypropylene (wPP) and coconut flour (CF). Each polymer composite was prepared with different ratios of CF introduced in the matrix. The composite prepared contained 10%, 20%, 30%, 40% and 50% CF respectively. 100% wPP was the control sample. The composite showed an increase in tensile strength and modulus, flexural strength and modulus, water absorption and impact strength with increase in CF. However there was a slight reduction in density of the NFRPCs with increase in CF due to poor dispersion of the fibres and void spaces in the matrix of the composites. The biodegradation rates of the NFRPCs were higher than that of wPP, with the highest biodegradation rate of 2.93% at 50% CF content after six months. The CF in the composites helped to increase the biodegradation rate as a result of its hydrophilic nature which permits the ingress of water into the matrix of the NFRPCs which aided degradation by action of micro-organism, photo-thermal and oxidative degradation. NFRPCs produced can be utilised for industrial and domestic applications and can also undergo biodegradation when disposed, indicating a more environmental friendly substitute compared to wPP. However to increase the rate of biodegradation additives such as transition metals may be incorporated into the matrix structure to increase biodegradation at a scale that would be much faster and economically more viable.

Esterified PVA‐lignin resin by maleic acid applicable for natural fiber reinforced composites

ABSTRACTThis article reports an esterified polyvinyl alcohol (PVA)‐lignin resin that is applicable for natural fiber reinforced polymer composites. To meet the requirement for the composites, a biopolymer‐based resin is necessary, which should well interact with the natural fiber with good waterproof behavior. By mimicking the relationship between cellulose, lignin and hemicellulose in wood, the esterified PVA‐lignin resin with maleic acid is provided. The preparation and characterization of the environment‐friendly resin are illustrated in this article. 180 °C of esterification reaction temperature and 40% of maleic acid contents are shown to be an optimum condition for the preparation of the resin. The esterified PVA‐lignin resin exhibits 13, 31, and 55% increase of its tensile strength, toughness, and failure strength, respectively. The water contact angle of the esterified PVA‐lignin resin is improved from 0 to 57°. The prepared resin is originally thermoplastic composite and it turned to be a thermoset resin by the esterification reaction at 180 °C, which is beneficial for composite processing. The developed resin is applicable for environment‐friendly and high strength‐natural fiber reinforced polymer composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48836.

A study on mechanical properties of bamboo fiber reinforced polymer composite

Abstract The modern, dynamic world can’t imagine its development without carrying the concept of advancement in composite materials. Various researches are going on in this field to achieve the desired standard. Natural fiber reinforced polymer composite (NFPC) has a huge affinity to interchange the composite made up of synthetic fiber. This is primarily because of the advantages like light-weight, non-toxic, non-abrasive, easy availability, low cost and biodegradable properties. The specific mechanical properties like specific tensile modulus and other specific properties of natural fiber gives a satisfying result for composites as compared to synthetic fiber based composites. The objective of article is to investigate the mechanical behaviour of short treated and untreated bamboo fiber reinforced epoxy based composites. Bamboo fibres with different length and contents are reinforced with epoxy resin to fabricate composite materials. The effect of fiber length and content on the mechanical behaviour of composites is studied.

Experimental Estimation of Relaxation Behavior for Hemp Fiber Reinforced Polypropylene Composite with Torque Rheometer

Relaxation behavior of natural fiber reinforced polymer composites exists in both solid and molten state and profoundly affects the control and optimization of processing parameters and dimensional accuracy of final products. The aim of this study was to establish an experimental estimating method to characterize relaxation behavior of polymer composite with traditional torque rheometer and investigate the effects of fiber concentration, dimension, and processing parameters on the relaxation behavior. Relaxation time of hemp fiber reinforced polypropylene composite were obtained by fitting the experimental torque data and corelated to the buckling deformation of packaging boxes manufactured by injection with the same injection parameters. The results show that all the increasing concentration of hemp fiber, higher rotor speed, and higher temperature can significantly decrease the relaxation time and result in a stable and better dimensional accuracy of injection packaging boxes. The finer fibers with the same weight concertation can bring an obvious reduction in relaxation time and buckling deformation. The proposed method for estimating relaxation behavior of polymer composite is a feasible and cost-effective way to investigate the viscoelastic properties of polymer composites close to the real processing conditions. And it can be widely used in optimization of processing parameters and performance of polymer composite products.

Effect of SiO2 nanospheres on mechanical, thermal and water absorption behaviours of luffa-coir/epoxy hybrid composites

To improve the utilization of natural fibre reinforced polymer composites, this study experimentally investigated the properties and reinforcing effect of SiO2 nanospheres as fillers on mechanical, thermal and water absorption behaviour of luffa-coir hybrid nanocomposites. Structural studies were carried out by x-ray diffraction, and fourier transform infrared spectroscopy. Fracture surface morphology was analyzed by field emission scanning electron microscopy, which confirms the homogeneous dispersion of SiO2 nanospheres into luffa-coir/epoxy hybrid composite. The mechanical test results direct to the inference that hybrid nanocomposite containing 3 vol% of SiO2 nanospheres acquired 49.6%, 78.26%, 13%, 80% and 43.16% of improved tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength respectively, compared with epoxy composite. Hybrid nanocomposites exhibited better thermal behaviour than epoxy composite such as decomposition temperature and residual char were increased by about 10%, 136% respectively with reduced thermal conductivity. Also, they showed lesser water absorption behaviour as 0.14%. Based on the results, the developed hybrid nanocomposites could be an effective replacement of non-biodegradable plastic fibre products for automobile interiors.

Review of natural fiber-reinforced engineering plastic composites, their applications in the transportation sector and processing techniques

Interest in natural fiber-reinforced polymer (NFRP) composites is growing rapidly in the transportation sector, especially as a replacement material for metals and synthetic fiber composites. The heightened interest is directly related to a need to produce lightweight and fuel efficient vehicles. Further, stringent legislation and greater environmental awareness is forcing transportation industries to select materials with a smaller carbon footprint. In such a context, NFRP composite materials are a good choice due to their low cost, low environmental impact, and relatively equivalent properties to metals and other composites. Most prior studies have examined commodity plastics such as polypropylene, polyethylene, and epoxy as the primary polymer matrix in NFRP composites and little work has addressed engineering plastics. Engineering plastics, which includes polycarbonate, polyamides, and polystyrene, are high performance thermoplastics with superior properties but relatively higher cost than commodity plastics. It has been claimed that even after recycling, engineering plastics properties are superior to those of commodity plastics, and thus, utilization of recycled engineering plastic in NFRP composites can help reduce waste and lower composite material costs. The aim of this review article is to explore the current status of engineering plastics reinforced with natural fibers such as flax, hemp, jute, and sisal and to examine their use in automotive, aerospace, and maritime applications. Properties and processing techniques of engineering plastics reinforced with natural fibers are also studied.

Evaluation of mechanical properties of jute fiber/carbon nano tube filler reinforced hybrid polymer composite

Abstract In present generation the use of natural fibres are increased highly in automobile sector as a potential renewable and eco-friendly materials. The natural fiber reinforced polymer composites are being presently used in various automobile industries as paneling elements in cars and in many internal parts. It can replace glass fiber reinforced plastics in many applications. This work focuses on dispersion of multi walled carbon nano tube in jute fiber and epoxy material. Five different proportions of multi walled carbon nano tube filler was taken (2%, 4%, 6%, 8%, 10%) to fabricate composite. The specimens were cut as per ASTM standard and the mechanical properties were evaluated as per ASTM testing methods. The results exhibited 3% volume nanotube composite has improved mechanical properties.

A review of important considerations in the compression molding process of short natural fiber composites

The study reviewed crucial parameters in the compression molding process for biocomposites affecting the properties of short natural fiber-reinforced polymer composites. The evaluation of drying and compounding processes between the polymer and short natural fiber was an essential consideration before the compression molding of biocomposites. Meanwhile, the parameters of molding temperature, compression pressure, and duration appeared to be other crucial and significant considerations requiring attention. In this study, all significant considerations affecting the performance of biocomposites were highlighted to provide essential information in the compression molding process of natural fiber composites topic. The findings from the present study are expected to improve the performance of short natural fiber-reinforced polymer composites and be an alternative to conventional polymer in various engineering applications in the future.

Experimental investigation on surface roughness of turned Nano-Khorasan based pineapple leaf fiber-reinforced polymer composites using response surface methodology

Now a day Nano based Natural Fiber Reinforced Polymer (NFRP) composite is important alternative material to conventional materials because of its superior characteristics. In general composite products are manufactured nearer to the required shape, but secondary operations like machining is necessary to obtain the required surface finish. Machining of NFRP composites is different than the machining of traditional materials. This paper focuses on the behavior and optimization of machining parameters on turning of Nano-Khorasan based Pineapple leaf fiber reinforced composites by using Response Surface Methodology (RSM) technique. The input factors studied are speed, feed, depth of cut and Nano-Khorasan mixing. The investigated output response was Average Surface Roughness (Ra). A Box-Behnken approach was employed to evaluate the optimum parameters to attain the minimum Ra. Based on this approach, a second order polynomial modal equation was generated for predicting response Ra. Also the relative effect of parameters on response Ra was studied by using ANOVA. The experimental result shows some interesting factors in context to the turning of Nano Khorasan based Pineapple leaf fiber reinforced polymer composites.

Thermo-mechanical and morphological characterization of needle punched non-woven banana fiber reinforced polymer composites

The purpose of this study is to employ a novel technique for the fabrication of natural fiber reinforced polymer composites that could stand toe to toe with glass fiber composites in terms of thermo-mechanical properties without any chemical treatment. The reinforcement fibers were extracted from the pseudostem of the nendran banana plant. Later a non-woven fabric composite consisting of banana fibers reinforced with unsaturated polyester (UPE) matrix was fabricated using the needle punching technique. Composite specimens were subjected to tensile, flexural, hardness, quasi-static indentation (QSI) and dynamic mechanical analysis (DMA) test for evaluating mechanical properties. However, the optimal properties was achieved at 40 wt% fiber content with an increase in tensile and flexural strength of 36% and 33% for needle-punched banana fiber composites (NPBFC) compared with random banana fiber composites (RBFC) respectively. It was also evidenced from the load bearing capacity and hardness of NPBFC having 2420 N and 87 HRRW, proves its superiority over RBFC and comparable with RGFC. Further, the viscoelastic properties of UPE and NPBFC were analyzed. Subsequently, the characteristic bonds of cellulose were represented through infra-red spectroscopy and the crystallinity index was exposed through X-ray diffraction analysis. In addition, thermal analysis was done and the stability of the optimized NPBFC witnessed was up to 260 °C. Also, morphology-properties correlation was established. Finally, the experimental results were validated using theoretical models. This study concludes that the synthesized novel NPBFC endorses its potentiality as a probable reinforcement in industrial safety helmet, automotive door panel and light weight structural applications.

Experimental analysis of adhesively bonded joints in synthetic- and natural fibre-reinforced polymer composites

The application of adhesively bonded joints in automotive industry has increased significantly in recent years mainly because of the potential for lighter weight vehicles, fuel savings and reduced emissions. The use of composites in making automotive body components to achieve a reduced vehicle mass has also continuously increased. Natural fibre composites have recently attracted a great deal of attention by the automotive industry due to their many attractive benefits (e.g. high strength-to-weight ratio, sustainable characteristics and low cost). However, the literature on natural fibre-reinforced polymer composite adhesive joints is scarce and needs further investigation. The main objective of this study was to evaluate and compare the mechanical performance of adhesively bonded joints made of synthetic- and natural fibre-reinforced polymer composites. Similar and dissimilar single lap joints bonded with a modern tough structural adhesive used in the automotive industry, as well as the epoxy resin AR260 (the same resin used in composite fabrication) were tested. It was found that the average failure loads varied significantly with adhesive material strength and adherend stiffness. Furthermore, it was also observed that failure mode has a significant effect in failure load. The jute-based natural fibre composites joints, both hybrid and purely natural, were superior in strength compared to the sisal-based natural composites joints.

Micromechanical modeling of the machining behavior of natural fiber-reinforced polymer composites

This paper aims to develop a 2D finite element (FE) model at microscale for numerical simulation of the machining behavior of natural fiber-reinforced polymer (NFRP) composites. The main objective of this study is to reproduce the experimentally observed specific cutting behavior of natural fibers within the composite material. Flax fiber-reinforced polypropylene (PP) composites are modeled separately using an elasto-plastic behavior with a ductile damage criterion for flax fibers and PP matrix, while the microscopic interfaces are represented using the cohesive zone modeling (CZM). Numerical outputs are compared with experimental results for the FE model validation. Results show that the proposed FE model can reproduce the cutting force with a good precision for a large cutting speed range (12–80 m/min). The FE model shows also an efficiency and accuracy in predicting the cutting behavior of flax fibers by reproducing the fiber deformation, the fibers torn-off, and the fracture of the interfaces during machining. Moreover, the FE model can be an effective tool for analyzing the quality of the microscopic interfaces in the NFRP composites after machining.

Influence of fiber volume fraction and curing temperature on mechanical properties of jute/PLA green composites

Rising environmental concerns and depletion of petrochemical resources have resulted in an increased interest in biodegradable natural fiber-reinforced polymer composites. In this research work, jute fiber has been used as a reinforcement and polylactic acid (PLA) as the matrix material to develop jute/PLA green composites with the help of compression molding technique. The effect of fiber volume fraction ranging from 25% to 50% and curing temperature ranging from 160°C to 180°C on different samples were investigated for mechanical properties and water absorption. Results obtained from various tests indicate that with an increase in the fiber volume fraction, tensile and flexural strength increases till 30% fiber fraction, thereafter decreases with further increase in fiber content. Maximum tensile and flexural strength of jute/PLA composites was obtained with 30% fiber volume fraction at 160°C curing temperature. The trend obtained from mechanical properties is further justified through the study of surface morphology using scanning electron microscopy.

Influence of sodium bicarbonate treatment on the aging resistance of natural fiber reinforced polymer composites under marine environment

Aim of the current study is to investigate how an innovative and eco-friendly chemical treatment based on sodium bicarbonate solution (10 wt%) can improve the aging resistance in marine environment of epoxy based composites, reinforced with flax and jute fibers. To this scope, treated and untreated fiber reinforced composites were manufactured through vacuum infusion technique. The resulting composites were then exposed to salt-fog spray conditions up to 60 days, according to ASTM B117 standard. The assessment of their durability was made by means of tensile, flexural quasi-static tests and Charpy impact tests. Furthermore, the water uptake evolution of each composite was monitored during the whole aging exposition.The experimental campaign evidenced that the beneficial effect of the sodium bicarbonate treatment on adhesion between flax fibers and epoxy matrix allows treated laminates to better retain their flexural properties during the salt-fog-exposition, in comparison to untreated laminates. Conversely, the proposed treatment leads to a slight worsening effect on the durability of jute fiber reinforced composites.

Optimization of Surface Roughness of Turned Nano-Khorasan Based Madar Fiber Composites Using Response Surface Methodology

Now a day Nano based Natural Fiber Reinforced Polymer (NFRP) composite is important alternative material to conventional materials because of its superior characteristics. In general composite products are manufactured nearer to the required shape, but secondary operations like machining is necessary to obtain the required surface finish. Machining of NFRP composites is different than the machining of traditional materials. This paper focuses on the behavior and optimization of machining parameters on turning of Nano-Khorasan based madar fiber reinforced composites by using Response Surface Methodology (RSM) technique. The input factors studied are speed, feed, depth of cut and Nano-Khorasan mixing. The investigated output response was Average Surface Roughness (Ra). A Box- Behnken approach was employed to evaluate the optimum parameters to attain the minimum Ra. Based on this approach, a second order polynomial modal equation was generated for predicting response Ra. Also the relative effect of parameters on response Ra was studied by using ANOVA. The experimental result shows some interesting factors in context to the turning of Nano Khorasan based Madarfiber reinforced polymer composites.

Mechanical Characterization of Roselle and Sisal Fibre Reinforced Polymer Composites

This paper details the mechanical characterization of natural fibre reinforced polymer composites. This includes the laboratory works such as tensile, flexural and impact tests. The samples of randomly oriented Roselle and Sisal fibre reinforced polyester composites were prepared for the laboratory tests. Theoretical modelling of the composites and calculation of the properties are also presented. The effect of alkali treatment of the fibre on the characteristics of the composite is also included. The results obtained are compared on various aspects to obtain a better performing composite.

Study of the reuse potential of the sisal fibers powder as a particulate material in polymer composites

The present work studied the reuse of sisal fiber powder, contaminated by industrial oil, resulting from the activities of a Brazilian textile industry. With the objective of reusing the contaminated sisal fiber powder residue, harmful to the environment, this work evaluate the potential of the use this sisal powder as reinforcement in composites. Natural fibre reinforced polymer composites became more attractive structural materials due to their high specific strength, lightweight and biodegradability properties. The mechanical behaviour of polyester resin based natural polymeric composites, made by using experimental planning (granulometry of sisal powder, fiber content and with or without styrene). Thus, combination of analysis of variance (ANOVA), response surface methodology (RSM) and experimental methods allowed evaluated, analyzed and validated the mechanical properties. The results obted showed that the waste from the sisal industry exhibits potential application in reinforcing composite materials Thus, different values of mechanical properties can be obtained by different interactions of the entry variables. Thus, the condition that exhibited high results of mechanical behavior independent of the addition of styrene were the particle size and fiber content 1680 μm and 2.5%, respectively. Therefore, the best results were stress (0.59 MPa), strain (5.68%), tenacity (2.01 E-05 MJ/m³) and energy at break (14 J) for the composite reinforced with sisal powder.

Development and mechanical characterization of novel polymer-based flexible composite and optimization of stacking sequences using VIKOR and PSI techniques

The development of natural fiber-reinforced polymer composites is becoming prominent in numerous engineering applications over the synthetic fiber-reinforced composites mainly because of their environment-friendly characteristics. This article deals with comparative study on selection of optimal stacking sequence (jute/rubber/jute (JRJ), jute/rubber/rubber/jute, and jute/rubber/jute/rubber/jute) of the jute/natural rubber-based completely biodegradable flexible composite using multi-attribute decision making (MADM) approaches namely hybrid entropy-VIse Kriterijumska Optimizacija kompromisno Resenja (VIKOR) and preference selection index (PSI) methods. Tensile strength, tear strength, specific impact strength, and specific wear rate are used as attributes for MADM methods. The results show good agreement between hybrid entropy-VIKOR and PSI methods used for stacking sequence selection. Scanning electron microscope analysis is carried out to study the failure mechanisms of the proposed flexible composite. The findings of the present study led to the choice of JRJ as the preferred stacking sequence among all the three stacking sequences considered as it exhibited the best overall properties compared to other two configurations of the flexible composite.

Experimental study on mechanical behavior of natural hybrid composites filled with ground nut shell ash

Abstract Nowadays, natural fiber reinforced polymer composites are widely used because of their advantageous properties like minimum density, maximum specific strength, low cost and easy availability. Manufacturing of natural fiber composite is easy as compared to the conventional methods. In the present scenario, due to an increasing interest in environmental consciousness with greenhouse effect, various industries have initiated the use of eco-friendly materials and are replacing hazardous materials with such eco-friendly materials. The present work aims to determine the tensile strength of okra and jute fibers reinforced in Epoxy LY-556 and XIN-100IN Resins. Okra fibers are developed from the stem of the plant of the Malvaceae family. Their use as reinforcement in polymer composites requires the basic knowledge of their mechanical properties. Jute fibers are developed from the best jute plants. The conclusions are based on their mechanical properties and behavior.

Study on Influence of Curing Temperature on Tensile Properties of Jute and Hemp Reinforced Hybrid Polymer Composites

Natural fiber reinforced polymer composites seem to be the best alternative material for the expensive and non-renewable synthetic fiber reinforced polymer composite materials. The strength of any composite material is greatly affected by interfacial bonding between matrix and fibers, pre and post curing operations performed. The present work is aimed at investigating the influence of curing temperature on tensile behaviour of Jute and Hemp fibers reinforced epoxy composite. The laminates are cured in a hot air oven for temperatures varying from 300C to 700C for the time duration of 8hrs. The maximum tensile strength of 112.89MPa is obtained for a specimen cured at 600C. As curing temperature increases the rate of polymerization also increases and bubbles that are trapped inside the composite get burst, thus reducing the voids formed during manufacturing. At a curing temperature of 700C, the tensile strength value reduced to 106.31MPa. At very high temperatures polymers emit some volatile reactants, which may get trapped below the surface leading to reduced strength of composite materials. The present work highlights that the curing temperature greatly influences the tensile behaviour of natural fiber reinforced polymer composite material.