Natural Fiber Reinforced Polymer Composites Research Articles

Efficient Process Chain for Processing Natural Fiber Reinforced Thermoplastics

Natural fiber reinforced polymer composites (NFRPC) are conventionally processed in compression molding process to shell-shaped components, which are mostly used in automotive industry. Therefore, natural fibers (NF) and polypropylene (PP) as matrix system are processed to a thermoplastic organic sheet. Organic sheets are heated in a contact heating press to temperatures above melting temperature of the matrix and then transferred to a forming press. In this paper, Acrodur®Power 2750 X (AP) is used as an alternative to PP. This thermoplastic matrix system enables an increase of fiber content to 75 wt.-% in NFRPC. Furthermore, infrared radiation (IR) with adapted wavelength was used as an alternative to conventional contact heating. To improve the heating behavior of NF/AP infrared and heat transfer additives were used. By adding heat transfer additives and using IR heating with adjusted wavelength, both heating time can be reduced from 45 seconds (NF/PP) to 25 seconds (NF/AP) and a contact heating press can omitted.

Review of Functional Properties of Natural Fiber-Reinforced Polymer Composites: Thermal Insulation, Biodegradation and Vibration Damping Properties

Natural fiber-reinforced polymer composites are attracting researchers’ attention as environmentally friendly and sustainable materials because of their low environmental load imposed by manufacture and disposal. Natural fiber-reinforced composites have comparable or somewhat inferior mechanical performance when compared to glass fiber-reinforced plastics (GFRP), but have some unique characteristics, which include low thermal conductivity, biodegradation in natural environments and effective suppression of vibration. This paper presents a review of the typical functionalities of natural fiber-reinforced composites including thermal insulation property, biodegradable property and vibration damping property. As described herein, the author will introduce each functionality and discuss the effects of many factors affecting the performance of each function. Consequently, this paper reports that composite materials that fully use their functionality rather than mechanical performance are important for the future development of natural fiber-reinforced composites.

Optimisation of the surface treatment of jute fibres for natural fibre reinforced polymer composites using Weibull analysis

The natural bast fibres such as jute, flax, kenaf, hemp, ramie are chemically modified for improving the interfacial adhesion with the hydrophobic matrices. Alkali treatment is amongst the widely used chemical treatment for the surface modification of these natural fibres. In this study, jute fibres are treated with 0.5, 4 and 25 wt.% sodium hydroxide (NaOH) solution at room temperature for 24 hours, 30 min and 20 min respectively. A comparison has been made between the physical and mechanical properties of these untreated and alkali treated jute fibres. Subsequently, a comparison between the cross-sectional areas of jute fibres before and after alkali treatment by using SEM analysis and circular fibre assumption is also made. The aim of the work is to optimise the alkali treatment processes of jute fibres with different concentrations of NaOH at room temperature. Two-parameter Weibull distribution is also applied to analyse the tensile properties of untreated and different alkali treated jute fibres. It has been observed that probabilistic tensile strength is an effective technique rather than presenting the average tensile strength. The study clearly demonstrates the jute fibre treated with 0.5 wt.% NaOH is more feasible and effective way to improve the mechanical properties of natural fibre reinforced composites.

Retraction Note to: Review on Tribological Performance of Natural Fibre-Reinforced Polymer Composites

The present work attempts to provide a review on tribological performance of natural fibre-reinforced polymer composites. Topics related to natural fibre, polymer, composites and tribology have been discussed. Composites have unique properties which can only be obtained by the combination of specific fibres and matrix materials. Today these composites are used in many areas such as automotive and construction which require good mechanical and tribological properties. However, shortcomings in the usage of these fibres, led by environmental concerns, have motivated researchers to explore the possibility of using natural fibres as an alternative.

Effect of Wet Spinning and Stretching to Enhance Mechanical Properties of Cellulose Nanofiber Filament

Long filament made with nanocellulose has been researched due to its eminent mechanical and physical properties for next generation of natural fiber reinforced polymer composites. Wet spinning process for long filament fabrication in conjunction with stretching method has advantages of high efficiency and low-cost. To fabricate homogeneous and strong cellulose nanofiber filament, this paper experimentally investigates the process parameters, including spinning speed, pre-dry temperature and inner diameter of needle. In addition to the spinning process, a mechanical stretching process is taken into account to further improve the mechanical properties of the cellulose nanofiber filament. The effects of wet spinning and stretching are evaluated by using scanning electron microscope, tensile test and 2D wide angle X-ray diffraction. As a result, the stretched cellulose nanofiber filament exhibits its Young’s modulus of 37.5 GPa and tensile strength of 543.1 MPa, which are significantly improved from the previous reports. All about the fabrication process, characterization and evaluation of the cellulose nanofiber filaments are illustrated.

A review on mechanical behavior of natural fiber reinforced polymer composites and its applications

In the last decade, natural plant fibers (jute, sisal, coir, banana, hemp, kenaf, flax, etc.) are getting attention from many researchers and academicians to utilize it as an alternate reinforcement of synthetic fiber reinforced polymer composites. These fibers are becoming a great replacement of conventional fibers (such as glass, carbon, and aramid) due to their light weight, low cost, carbon neutrality, fairly good mechanical properties, high specific strength, and biodegradability characteristics. Some chemical treatments are required to enhance the fiber matrix interfacial strength and to minimize the moisture absorption by these fibers which would ultimately improve physico-mechanical properties of these fiber reinforced composites. This paper is a review on mechanical properties of the natural plant fiber reinforced polymer composites and various factors affecting the mechanical performance of it. The tribological behavior of natural fiber reinforced polymer composites and scanning electron microscope analysis are also discussed. Some mathematical models are mentioned which are useful to predict mechanical behavior of the composites. It is found that Halpin–Tsai equation is the most effective equation amongst others in predicting Young’s modulus for short-fiber reinforced composites with minimum error. The applications of natural plant fiber reinforced polymer composites in various engineering fields are discussed.

Effect of nanofillers on the properties of natural fiber reinforced polymer composites

Abstract Nanofillers are bringing exemplary changes in the field of material science and polymer composites. In this sophisticated process a small amount of material is added to a variety of polymers and other materials which can drastically improve the performance and quality of materials including thermal, mechanical, water absorption and flame retardancy etc. Nano fillers can be considered as additives in solid form which can upgrade the various properties of original materials without increasing the density of materials. Now a days researchers are using natural fibers as an alternative reinforcement of synthetic fibers in polymer composites because of their cost effectiveness, biodegradability, lower weight, good mechanical properties and sustainability but the compatibility issue of hydrophobic polymer matrix and hydrophilic fibers is still a concern which ultimately leads to degradation in performance of these composites. Attempts have been made to increase the compatibility between the polymer matrix and the natural fibers with the help of various surface treatments strategies like alkylation, acetylation, maleated coupling etc. Nano particles or nano fillers have tremendous potential to be used as filler material which can improve the properties of polymer composites. Academicians and researchers have used Nano clay, Nano SIO2, carbon nanotubes and many other nanofillers in natural fiber reinforced polymer composites for improvement in properties. Nano clay has shown its potential in decrease in water absorption in sisal fiber reinforced composites which is highly desirable similarly Nano SIO2 has been proven very useful for the improvement in mechanical properties of these composites moreover carbon nano tubes have also exhibited its importance in improvement of mechanical and water absorption properties of bamboo and ramie fiber reinforced polymer composites. Present study provides a review of recent advances on the effect of nanofillers on the properties of natural fiber reinforced polymer composites.

Flexural and Specific Wear Rate of Seawater Aged Bamboo, Jute and Glass Fiber Reinforced Polymer Hybrid Composites

Abstract Natural fiber reinforced polymer composites have been used in different industries because of its high specific strength, modulus, cheaper and biodegradability. However, natural fiber reinforced polymer composites have lower mechanical properties and degrades its mechanical properties through seawater aging or moisture absorption than the composites having synthetic fiber. Therefore, the hybridization of natural fiber with synthetic fiber is needed to improve its mechanical properties in seawater aged condition. In this present investigation jute, bamboo and glass fiber is taken as the reinforcement medium for the preparation of the polymer hybrid composites. Three variety of hybrid composites such as [GJB]s,[GBJ]s,[JBG]s were considered for this investigation. The specimens were aged in seawater for 30days. It is found that [GBJ]s hybrid composite absorb more amount of seawater than the other two hybrid composites followed by degradation of its flexural strength by 42% and modulus by 33%. The [GBJ]s type hybrid composites shows lowest specific wear rate than the other two hybrid composites in dry condition and for seawater aged condition [JBG]s type hybrid composites shows minimum specific wear rate as compared to other hybrid composites

Study on Drilling of Woven Sisal and Aloevera Natural Fibre Polymer Composite

Natural fibre reinforced polymer composites are the materials formed by a matrix and a reinforcement of natural fibre. Natural fibre reinforced polymer composites are light in weight, economical, low density, high specific strength, modulus relative no abrasiveness, ease of fibre surface modifications wide availability and are available in variety of forms. They have low densities, comparable material properties, and high moulding flexibility and are environmental friendly. By modifying either the resin system or the natural fibre, natural fibre composites can be designed for different applications ranging from products of commodity to aerospace applications. In this work composite laminate was prepared with natural fibre such as sisal and aloevera with epoxy resin using hand layup technique. The present investigation is an attempt to study the factors that influence the delamination of drilled sisal and aloevera natural fibre reinforced composites using (ɸ 6mm, ɸ 8mm, ɸ 10mm) carbide tip drill bit. Surface roughness test and delamination is carried out on drilled natural fibre composites.

Mechanical Characteristics and Terminological Behavior Study on Natural Fiber Nano reinforced Polymer Composite – A Review

Abstract In recent years, natural fibers with nano polymer composites are useful in the field of research, Engineering and Science as well it is used as an alternative reinforcement for conventional composite. Natural fibers are not only strong and light weight, but also relatively cheap and have properties like high specific strength, low weight, non-abrasive, eco-friendly and biodegradable. Generally used natural fibers like Jute, Sisal, Banana, Hemp, etc…, The reuse of waste natural fiber reinforcement of polymer is a sustainable option for the environment. The polymeric matrix materials along with suitable and proper filler and better filler/matrix create strong interaction between advanced and new methods or approaches. This enable to develop polymeric composites which shows great prospective applications in the construction of buildings, automotive, aerospace and packaging industries. Nano polymer composite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nano polymer composites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid nano-polymer composites exploit the synergy between natural fibers in a nano-reinforced polymer-based composites. This leads to improve the properties along with the environmental appeal. The mechanical properties of a natural fiber reinforced nano polymer composite depend on parameters like fiber strength, fiber length, chemical treatment and orientation in addition to fiber-matrix interfacial bond strength. This review article aims at the clarification of the research and development in the improvement of mechanical properties of natural fiber reinforced polymer composites along with end applications.

Treatment of Shear Stress versus Shear Rate Data for Natural Fiber Reinforced Polymer Composites: A Discussion

The rheological properties of melt jute fiber reinforced polypropylene (PP) composites were conducted at constant shear stress. The measured shear stress and shear rate data are fitted to a power law model for measuring stress-independent melt viscosity of the composites. The viscosity increased with the increase of fiber loading and decreased with the rise of temperature. The flow behavior index, n was found to decrease with the increase of fiber loading and increase with the rise of temperature. The shear stress and shear rate data collected from different specialized research journals have also been fitted to the power law model to measure the stress-independent melt viscosity and flow index as in all the previous literatures viscosity is treated as stress dependent parameter. It was found that the dependence of the viscosity and the flow index observed from previous literature data with fiber loading and temperature was quite consistent with the present study.

Natural fiber reinforced polymer composites: history, types, advantages, and applications

Nowadays, the use of natural fiber reinforced polymer-based composites is gradually increasing day by day for their many advantages for civil engineering construction applications. Due to their many advantages for polymer-based composite materials are widely used in civil construction, automobiles, aerospace, and many others. Natural fibers such as jute, kenaf, pineapple, sugarcane, hemp, oil palm, flax, and leaf, etc. are cheap, environmentally friendly, renewable, completely and partially biodegradable which can be utilized to obtain new high-performance polymer materials. These composites are having satisfactory mechanical properties (i.e. tensile properties, flexural stress-strain behavior, fracture toughness, and fracture strength) which make them more attractive than other composites. Due to easy availability and renewability, natural fibers can be used as an alternative of synthetic fibers as a reinforcing agent. The aim of this paper is to review different natural fibers reinforced based polymer composites with mechanical characterization, applications, also shows the opportunities, challenges and future demand of natural composite material towards civil applications.

Experimental and Micromechanical ThermalCharacteristics of Jute Fiber Reinforced Polyester Composites

Abstract An understanding of the thermal analysis of natural fiber reinforced polymer composites is extremely important in the structure-property relationship and industrial production. The temperature dependent properties such as thermal conductivity, thermal diffusivity and specific heat are an important and plays a significant role in determining their heat conduction/insulation capability. In this paper, short jute fiber reinforced polyester composites were prepared by varying the fiber loading (0–40 wt.%). The physical and thermal characteristics were evaluated as per ASTM standards. The experimental thermal conductivity results were validated with the results obtained by analytical methods existing in the literature. The analytical methods like rule of mixture, geometric mean, and Lewis and Nielsen approaches have been used to evaluate the properties of composite material. The thermal conductivity values predicted by analytical methods are in good agreement with the experimental results and observed an acceptable range. The density of the jute fiber composites was increases with increase in the fiber loading. The specific heat capacity and thermal diffusivity of the jute fiber composites were decreases with increase in the fiber loading. The results indicated that jute fiber reinforced polyester composites were suitable for building components and automobiles in order to reduce the energy consumption.

The Green Composites: Millet Husk Fiber (MHF) Filled Poly Lactic Acid (PLA) and Degradability Effects on Environment

This study provides an overview on green composites degradability. Practically, the main drawbacks of using natural fibers are their poor dimensional stability, degradability and high degree of moisture absorption. While, end use of product from natural fiber filled or reinforced composites has become subject of concern to material engineers and scientist. The major properties of natural fiber reinforced polymer composites are greatly dependent on the hydrophilic tendency and dimensional stability of the fibers used, morphology aspect ratio for long fiber, while voids for powder fibers. The effects of chemical treatments on cellulosic fibers that are used as reinforcements for thermoplastics were studied. The chemical source for the treatments is alkalization. The significance of chemically-treated natural fibers is seen through the improvement of mechanical properties. The untreated fiber composites degrade faster in municipal soil compared to treated fiber composites.

Influence of fillers on mechanical properties of prosopis juliflora fiber reinforced hybrid composites

Abstract Natural fiber reinforced polymer composites are increasing due to properties like bio-degradability and easily available. The main aim of this paper is to evaluate the influence of filler materials on the mechanical properties of the prosopis juliflora fiber reinforced hybrid composites. Composite samples are fabricated with three different filler materials (CaCO3, TiO2 and Al2O3) with constant weight proportion along with the variation of the fiber weight content. Moreover, composite with Al2O3 filler material attained highest mechanical properties than the other two filler materials. SEM analysis also proved that the bonding between the reinforcements and matrix are uniformly dispersed.

Reviewing the Development of Natural Fiber Polymer Composite: A Case Study of Sisal and Jute

Natural fibers that are mainly from plants, animals and regenerated sources are degradable and environmentally friendly as they absorb carbon dioxide and release oxygen, they are cost effective when compare to the synthetic fibers. These materials mainly from plant are used initially for domestics’ purposes. They have recently been introduced to some industries, such as automotive, aircraft, marine and buildings, arising from their excellent mechanical, physical and chemical properties. The common natural fibers used for Natural Fiber Reinforced Polymer Composites (NFRPC) are, cotton, sisal, coir, jute, hemp, flax, banana, bamboo etc. Several researches and publications on natural fibers and its composite show that despite the properties of these fibers, their applications were limited to non-structural applications either for interior or exterior applications just for their environmental and low-cost benefit with less concern for their strength capabilities. Sisal and jute are fibers from vegetable and bast plants that had been proved to have exhibited excellent tensile and flexural properties (bast composite) and best impact properties (vegetable composite), were also restricted to non-structural applications only. This paper reviewed the present status and future expectations of natural fiber reinforced composites in structural applications using sisal and jute fiber reinforced polymer composites as a case.

Material Selection of a Natural Fibre Reinforced Polymer Composites using an Analytical Approach

Material selection has become a critical part of design for engineers, due to availability of diverse choice of materials that have similar properties and meet the product design specification. Implementation of statistical analysis alone makes it difficult to identify the ideal composition of the final composite. An integrated approach between statistical model and micromechanical model is desired. In this paper, resultant natural fibre and polymer matrix from previous study is used to estimate the mechanical properties such as density, Young’s modulus and tensile strength. Four levels of fibre loading are used to compare the optimum natural fibre reinforced polymer composite (NFRPC). The result from this analytical approach revealed that kenaf/polystyrene (PS) with 40% fibre loading is the ideal composite in automotive component application. It was found that the ideal composite score is 1.156 g/cm3, 24.2 GPa and 413.4 MPa for density, Young’s modulus and tensile strength, respectively. A suggestion to increase the properties on Young’s modulus are also presented. This work proves that the statistical model is well incorporated with the analytical approach to choose the correct composite to use in automotive application.

Comparison of Mechanical Properties of Natural Fiber Reinforced Polymer Composites

Comparison of Mechanical Properties of Natural Fiber Reinforced Polymer Composites

Experimental study towards inter-laminar fracture toughness of different fibre reinforced polymer composites

Throughout the years, fibre reinforced polymer (FRP) composites have been developed as new valuable materials which are suitable for a number of engineering applications due to its high performance such as high strength and superior characteristics. However, FRP composites are susceptible to the damage such as inter-laminar delamination, which tend to greatly reduce the stiffness of the composite structure. The aims of this study are to compare and evaluate the Mode I inter-laminar fracture toughness of the natural FRP composites and the synthetic FRP composites. Samples from flax, glass and carbon fibres were prepared using resin infusion technique. The Mode I inter-laminar fracture toughness of these composites stress were tested under tensile loading by using a Double Cantilever Beam (DCB) test in accordance to the ASTM standard. The results showed that the fracture toughness of the natural FRP composites increases with delamination length. Whereas, for the synthetic FRP composites, the fracture toughness was scattered, in which it was slightly increased within the first few delamination length, gradually decreased and increased again with respect to the delamination length.

Axial strength and deformability of concrete confined with natural fibre-reinforced polymers

This paper presents the results of an experimental study on the compressive behaviour of concrete confined by natural fibre-reinforced polymer (NFRP) jackets which are formed by embedding sisal fibres in an epoxy resin matrix. The sisal fibres are one of the cost-effective materials for use in seismic strengthening applications where a moderate increase in strength and ductility is required. This study has two main objectives: the first is to investigate the effectiveness of NFRP composites in increasing the strength and deformability of confined concrete. For the second objective, the performance of existing strength models developed for conventional synthetic fibre-reinforced polymers is assessed. For this, 36 concrete specimens were tested under uni-axial compression. The study parameters covered the NFRP thickness, concrete strength and cross-sectional shape. Test results indicated that the NFRP confinement is significantly effective in increasing the strength and deformability of confined concrete. Furthermore, it is found that none of the existing considered models is capable of accurately predicting the ultimate strength and strain of NFRP-confined concrete. Finally, new strength models are proposed to predict the compressive strength of circular and square sections. The strengths predicted by the proposed models are found to have a good agreement with experimental results.