Recent progress in hybrid biocomposites: Mechanical properties, water absorption, and flame retardancy

This article belongs to the Special Issue Mechanical Properties of BiocompositesBio-based composites are reinforced polymeric materials in which one of the matrix and reinforcement components or both are from bio-based origins. The biocomposite industry has recently drawn great attention for diverse applications, from household articles to automobiles.This is owing to their low cost, biodegradability, being lightweight, availability, and environmental concerns over synthetic and nonrenewable materials derived from limited resources like fossil fuel. The focus has slowly shifted from traditional biocomposite systems, including thermoplastic polymers reinforced with natural fibers, to more advanced systems called hybrid biocomposites. Hybridization of bio-based fibers/matrices and synthetic ones offers a new strategy to overcome the shortcomings of purely natural fibers or matrices. By incorporating two or more reinforcement types into a single composite, it is possible to not only maintain the advantages of both types but also alleviate somedisadvantages of one type of reinforcement by another one. This approach leads to improvement of the mechanical and physical properties of biocomposites for extensive applications. The present review article intends to provide a general overview of selecting the materials to manufacture hybrid biocomposite systems with improved strength properties, water, and burning resistance in recent years

Reinforced Polymer Composites

This book, consisting of 21 articles, including three review papers, written by research groups of experts in the field, considers recent research on reinforced polymer composites. Most of them relate to the fiber-reinforced polymer composites, which are a real hot topic in the field. Depending on the reinforcing fiber nature, such composites are divided into synthetic and natural fiber-reinforced ones. Synthetic fibers, such as carbon, glass, or basalt, provide more stiffness, while natural fibers, such as jute, flax, bamboo, kenaf, and others, are inexpensive and biodegradable, making them environmentally friendly. To acquire the benefits of design flexibility and recycling possibilities, natural reinforcers can be hybridized with small amounts of synthetic fibers to make them more desirable for technical applications. Elaborated composites have great potential as structural materials in automotive, marine and aerospace application, as fire resistant concrete, in bridge systems, as mechanical gear pair, as biomedical materials for dentistry and orthopedic application and tissue engineering, as well as functional materials such as proton-exchange membranes, biodegradable superabsorbent resins and polymer electrolytes

A review on coir fibre, coir fibre reinforced polymer composites and their current applications.

Coir fibre has generated much interest as an eco-friendly, sustainable fibre with low density. This review findings show that coir fibres are abundant, with an average global annual production of 1019.7 × 103 tonnes, with about 63% of this volume produced from India. Extraction of coir has been carried out through water retting. However, the retting period has been limited to 4–10 months. The lignin content of coir is more than 60% higher than that of other natural fibres; hence, coir could double as a source of lignin for other applications. The diameter of coir fibres varies from 0.006 mm (Vietnam) to 0.577 mm (Thailand), and their tensile strength ranges from 68.4 MPa (Tanzania) to 343 MPa (Vietnam). Coir fibres from Vietnam and India exhibit the highest elongation at break (63.8%) and the highest Young’s modulus (6 GPa), respectively. More than 50% of the researchers within the scope of the reviewed studies employed the hand layup (HLU) manufacturing method with an epoxy resin matrix. Fibre volume fractions used range between 10%–65%. An outstanding tensile strength of 62.92 MPa at 49% fibre volume fraction was recorded for coir composites where the fibres were unidirectionally oriented and stacked in three layers, manufactured using epoxy resin and the HLU technique. Only a few works have been done using Vacuum-assisted resin transfer moulding (VARTM). The curing of composites was mostly carried out at an unspecified temperature and duration. A defined fibre volume fraction with a defined mixing and mixing time of the matrix is imperative. The degree of uniform dispersity of the fibres in the matrix is lacking. The creep behaviour of coir composites, coating and wider treatment parameters need to be explored for advanced applications. Recent findings on the applications of coir composites are equally highlighted

Mechanical properties of bamboo fibre biocomposite: a review / Anith Athierah Aziz, Sallehan Ismail and Siti Akhtar Mahayuddin

Global environmental concerns and awareness of renewable green resources are growing demand for eco-friendly, sustainable, biodegradable natural fiber reinforced composites. Natural fibers have essential physicochemical and mechanical qualities in the composite sector. Recent interest in bamboo fiber focuses on replacing or reducing nonrenewable glass fiber as bamboo bio-composites are eco-friendly. Different processing parameters such as fiber extraction and surface modification of the composites affect the characteristics of composites. To solve the issues relating to reinforcing fibers, polymer matrix materials, and composite manufacturing procedures, various investigations on bamboo fiber bio-composites have been done in recent decades. Bamboo fiber has poor interfacial adhesion with polymer matrix and low mechanical qualities due to its hydrophilic nature. The purpose of this article is to summarize the research done on bamboo fiber bio-composites during the previous few decades. As a result, this article provides a critical review of the developments in bamboo fiber bio-composites and key results presented in the literature, with a focus on the processing procedure and ultimate properties of bamboo fibers with polymeric matrices. This research can serve as a guide for future reference on bamboo fiber reinforced composites and promote their utilization

Physical, mechanical and abrasive wear behaviour of jute fiber reinforced polymer composites

Now-a-days, abrasive wear of engineering and agricultural machine components caused by the abrasive particles is a major industrial problem. Therefore, a full understanding of the effects of all system variables on the abrasive wear rates is necessary in order to undertake appropriate steps in the design of the machinery and the choice of materials to reduce/control wear. The need for the use of newer materials to combat wear situations has resulted in the emergence of polymer based system. Polymers and their composites form a very important class of tribo engineering materials and are invariably used in mechanical components where wear performance in non-lubricated condition is a key parameter for the material. The advantages of these materials are light weight, excellent strength to weight ratios, resistance to corrosion, non-toxicity, easy to fabricate, design flexibility, self-lubricating properties, better coefficient of friction, and wear resistance. The present research work is undertaken to study the physical, mechanical and three body abrasive wear behaviour of jute fiber reinforced polymer composites. Three different forms of jute fiber (short jute fiber, bidirectional jute fiber and needle punched nonwoven jute fiber) are considered for the present research work. Attempts have been made to explore the possible use of needle punched nonwoven jute fibers as reinforcement for polymer composites. The design of experiments approach using Taguchi methodology is employed for the parametric analysis of abrasive wear process. The study reveals that abrasive wear performance of needle punched nonwoven jute based composites is better than that of the short and bidirectional jute fiber reinforced composites. The morphology of abraded surfaces is examined by using scanning electron microscopy (SEM) and possible wear mechanisms are discussed. Finally, the ranking of the composite materials under study is done by using AHP-TOPSIS method based on their physical, mechanical and abrasive wear attributes

Manufacturing of coir fibre-reinforced polymer composites by hot compression technique

This present chapter describes the manufacturing technique and properties of coir fibre-reinforced polypropylene composites manufactured using a hot press machine. The effects of basic chromium sulphate and sodium bicarbonate treatment on the physical and mechanical properties were also evaluated. Chemical treatment and fibre loading generally improved the mechanical properties. Five-hour basic chromium sulphate and sodium bicarbonate-treated coir-polypropylene had the best set of properties among all manufactured composites. Chemical treatment also improved water absorption characteristics. This proves that chemical treatment reduced the hydrophilicity of the coir fibre. Overall the hot compression technique was proved to be successful in manufacturing good quality coir reinforced polypropylene composites

A study on mechanical behavior and damage assessment of short bamboo fiber based polymer composites

Now-a-days, natural fiber reinforced polymer composites are increasingly being used for varieties of engineering applications due to their many advantages. Among natural fibers, bamboo has been widely used for many such applications due to its availability. Since these composites are finding wide applications in highly dusty environment which are subjected to solid particle erosion, a study of their erosion characteristics are of vital importance. Generally solid particle erosion, a typical wear mode leads to material loss due to repeated impact of solid particles. For a composite material, its mechanical behavior and surface damage by solid particle erosion depends on many factors. Attempts have been made in this paper to explore the potential utilization of bamboo fiber in polymer matrix composites. Therefore, the present research is focused on the mechanical and erosion wear behavior of short bamboo fiber reinforced composites filled with Alumina (Al2O3) particulate. It further outlines a methodology based on Taguchi’s experimental design approach to make a parametric analysis of erosion characteristics. Finally, the morphology of eroded surfaces is examined using scanning electron microscopy (SEM) and possible erosion mechanisms are identified

Synthesis and characterization of composites: thermoplastic/lignocellulosic fibers from the Biskra region

This study's main goal was to make an eco-friendly composite from palm petiole fibers that could be used as fillers in a linear low-density polyethylene (LLDPE) matrix with a loading of 15–25 wt% and to look into how the composites age naturally. To achieve this main objective, lignocellulosic fibers were prepared using successive treatments on the fiber surface (NaOH, hydrogen peroxide, and acetic anhydride). The NaOH pretreatment aimed to overcome the recalcitrance of lignocellulosic biomass. FTIR showed that pretreatment with NaOH helped the peroxide hydrogen treatment of NaOH-petiole fibers to break down biomass without separating it into different parts. This made it possible to get micrometric-sized lignocellulosic fibers. These lignocellulosic fibers that have been extracted are hydrophilic, which means that the hydroxyl groups in the fibers interact with water molecules. The hydrophilic nature of these lignocellulosic fibers often results in poor compatibility with hydrophobic polymeric matrices. Surface modification is therefore necessary to make them more hydrophobic and compatible with the hydrophobic matrices. For this reason, we treated the lignocellulosic fibers with acetic anhydride, which is used to modify the surface of the fibers and make them more hydrophobic. The scanning electron microscopy (SEM) results showed that the enhanced interfacial adhesion between the fibers and the matrix makes treated composites more rigid and more homogeneous, which means that the fibers are distributed more uniformly. The tensile modulus and flexural strength were all enhanced by adding 15-25% of untreated palm petiole fibers, while the tensile strength was decreased. Palm-petiole fiber composites' storage modulus increased, and the acetylated-alkali fiber (FNA) reinforced LLDPE composite showed the highest storage modulus. Loss modulus increased when palm petiole fibers were strengthened. The Tan delta of composites made from palm petiole fibers was low initially but expanded with fiber addition. After exposing the LLDPE/PPF composites to natural aging, we observed, by IRTF, the formation of several oxidation products, an increase in the crystallinity rate, and Young's modulus. Furthermore, the SEM images clearly show that the degradation is severe with aging. We concluded that successive treatments improve the performance of the palm petiole fiber and have the potential to create a new type of sustainable and eco-friendly material for various applications