Extraction of bamboo fibers and their use as reinforcement in polymeric composites

Chapter three - Extraction methods for bamboo fibres: various extraction methods, different types of bamboo fibres

Natural particles and their composites are important in materials science, where a significant attentiveness is being displayed in the usage of natural particles as reinforcement in polymer composites. The purpose of this research is to investigate the effect of the walnut shell particles as reinforcing fillers in a matrix composite. So, the amount composite examples were advanced through varying the percentage by weight of filler (3, 5, 7, and 9%) in an epoxy and unsaturated polyester polymer. Composite samples were mechanically characterized by tensile tests, flexural tests, hardness tests, and the Izod impact test. The tensile strength and impact strength of epoxy resin were increased after adding organic waste filler. The highest values of tensile strength and impact strength happened at 7% wt. The flexural strength and hardness of shore D increased with the percentage of walnut shell particles. The highest values of flexural strength and hardness were found at 9% wt. The results show that the mechanical properties of epoxy composite are better than the mechanical properties of unsaturated polyester composite when walnut shell particles are added.

The utilization of polymer composites in the automotive field is expanding due to their characteristics such as strength, stiffness, and light weight. Polypropylene (PP) is one of the thermoplastic polymers widely used in composite manufacturing due to its lightweight, corrosion-resistant, and recyclable properties. However, to improve its mechanical properties, modifications using natural reinforcements and coupling agents continue to be made. Corn husk fiber is a natural resource that has potential as a natural reinforcement in polymer composites, it has the advantages of good tensile strength, light weight, and is biodegradable. The addition of Aluminium Oxide (Al2O3) and Maleic Anhydride (MAH) as coupling agent can improve the adhesion between fiber and polymer matrix, support more even load distribution, and optimize the mechanical properties of the composite Al2O3 and MAH on the mechanical properties of PP composites. The composition used was polypropylene: corn husk fiber rasio :Al2O3: MAH, namely 90:5:5:0, 89:5:5:1, 87:5:5:3, and 85:5:5:5% by weight. Tensile strength test using Universal Testing Machine (UTM) and crystallinity test using Differential Scanning Calorimetry (DSC) were conducted to evaluate the material performance. The highest value of tensile strength and crystallinity in the composition with 0 %weight MAH. The results of these tests, showing that the greater the composition of corn husk fiber has an influence on the decrease in tensile strength and crystallinity of the composite.

The ecological conservation in the current global scenario has led scholars to use natural fibers as a reinforcement in composites that resulted in the exploration of new natural cellulose fibers. This research investigates the extraction and characterization of natural cellulose fibers from the stems of Buxus sempervirens (BS) plants, which are used to produce various products. Manual retting of stems resulted in Buxus sempervirens fibers production, which was then evaluated for their physical, chemical, thermal, crystallographic, and morphological characteristics. The results elucidated that BS fibers had a cellulose percentage of 51.78%, 18.42% hemicellulose, and 17.36% lignin. The Fourier Transform Infrared Spectroscopy results validated the chemical constituents. Crystallographic investigations utilizing X-Ray diffraction revealed a crystalline index of 18.05%. The thermogravimetric analysis of BS fibers showed char residue of 33% and a maximum degradation temperature of 263°C. The BS fibers revealed good surface interlocks that can be inferred from Scanning Electron Microscope. Thus, from the results compared with other natural fibers, we demonstrate that Buxus sempervirens fibers can be effectively used as reinforcement in polymeric composites.

The use of bamboo fibres as a reinforcement in polymer composites has gained significant attention due to their sustainability and renewable characteristics. However, the long-term performance of these composites under tropical weather exposure, such as immersion weathering, remains a crucial area of research. The present study involved the preparation of rHDPE composites with different percentage of bamboo fibres were prepared and subjected to accelerated immersion weathering to simulate outdoor conditions. The tensile strength of composites was evaluated at different time intervals during the weathering process. The results demonstrate that immersion weathering significantly influences the mechanical properties of the rHDPE composites reinforced with bamboo fibres. Tensile strengths of the composites showed a reduction with increasing exposure time. This reduction was more pronounced in composites with higher bamboo fibre content, suggesting a synergistic effect between the composite composition and weathering conditions. Understanding the degradation mechanisms and the complex interaction between composite composition and weathering exposure is essential for optimizing the design and application of these eco-friendly materials in outdoor environments. Further research in this field is needed to develop strategies to enhance the weathering resistance of such composites and expand their potential applications in areas such as construction, automotive, and outdoor furniture, where durability and environmental sustainability are of paramount importance.

This current study aims to extract bamboo fibers from different species of bamboo using the mechanochemical method and investigate their properties. The bamboo species used in this study were Dendrocalamus, Bambusa balcoaa, Oliveri, Asamica, and Chimono. The vacuum-pressurized impregnation treatment process was employed for treating the bamboo. The mechanochemical method was chosen for extracting the bamboo fibers due to its simplicity and efficiency. The yield percentage of the bamboo fibers was determined. X-ray diffraction (XRD) analysis showed an increase in the crystallinity of the bamboo fibers with subsequent treatments in the presence of NaOH, as evidenced by two well-defined peaks at 2θ = 17.6° and 2θ = 22.7°. FTIR analysis revealed the presence of numerous hydroxyl groups in the bamboo fibers, indicated by the –OH expanding and contracting vibration at the band around 3311 cm−1. Thermal gravimetric analysis (TGA) was conducted to investigate the thermal stability of the bamboo fibers, and the results demonstrated that chimino bamboo fiber exhibited the highest level of thermal stability compared to other treated bamboo fibers. Scanning electron microscopy (SEM) was employed for morphological characterization, providing insights into the surface morphology of the bamboo fibers. Based on the findings, it can be inferred that bamboo fibers, particularly of the chimino type, have the potential to serve as a viable reinforcement in polymeric composites for lightweight applications in various industries, such as automotive, aerospace, and packaging.

Polymer composites are mainly employed as an industrial material because of their chemical and corrosion resistance, especially in mining applications. As a result of the growing demand for biodegradable, ecological, and recyclable materials, organic fibres are widely used as reinforcement in polymer composites in recent years. The challenges arising from polymer composites, like environmental impact, moisture absorption, Thermomechanical property deterioration, lower durability in mining applications are discussed in this review. This work analyses the influence of certain physicochemical modifications on the reinforcement and matrix in polymer composites for mining purpose. This investigation was to understand the effectiveness of physicochemical modifications, specifically cryogenic treatment, on reinforcements and matrix to overcome the above mentioned challenges. This study also highlights the morphological and thermal changes due to the modifications. Results show the effect of these modifications on the composite and its constituents, cryogenic treatment on the organic fibre reinforcements showed increased moisture resistance, higher cellulose composition and mechanical properties, exposing the potential of using organic fibre-reinforced polymer composite in Mining applications.

This paper presents a multi-aspect analysis of whether it is feasible and practical to process natural (plant) fibers into fabrics and mats as homogeneous or hybrid reinforcement in polymer composites for use in various industrial sectors. The current, stringent environmental rules of safe recycling and/or disposal of worn or damaged products at the end of their lifetime require new reinforcing materials to be used in polymer composites that need to meet the criteria of energy and material recycling. The paper comparatively analyzed chemical compositions of some selected (plant) natural fibers and compared their physical and chemical properties relative to commonly used synthetic (mineral and carbon) fibers. The world production of respective species of natural fibers has been presented. Industrial hemp was singled out as the possible quality reinforcement to be used in polymer composites in Poland and in Europe. The paper also provided a broader historical perspective of hemp’s importance for mankind over the past 28 thousand years. Hemp’s history and its impact on human development have been discussed. Finally, the paper compiled knowledge on industrial hemp use, agriculture, and processing as well as its current legal status in Poland and abroad.

The potential of using date palm fibres as reinforcement for polymeric composites

Background: Natural fibres are getting substantial attention as reinforcement in polymer composites. However, they are commonly recognised to have poor compatibility with polymers. Hence, it is important to enhance the interfacial bonding of natural fibres. Recent patents have highlighted several alternatives to improve the interfacial characteristics. Objective: In this study, the interfacial shear strength of untreated and 10wt% sodium hydroxide (NaOH) treated bamboo fibre reinforced polyester composites was investigated. Method: The bamboo fibre length was fixed at 7mm in both cases. The interfacial shear strength was measured through single fibre pull-out test (SFPT) and subsequently analysed using Weibull distribution plot. Results were also compared with the data from literature. Finally, scanning electron micrographs (SEM) were captured to analyse the debonded surfaces of both matrix and fibre. Results: Results showed that the interfacial shear strength of the treated fibre was improved by almost three fold higher than the untreated fibre. In addition, Weibull analysis revealed that the Weibull moduli were similar for both untreated and treated fibres. This suggested that surface impurities were formed on the treated fibre due to the damage induced by sodium hydroxide. Furthermore, scanning electron micrographs showed that alkalisation has modified the fibre surface morphology and improved the overall surface quality for better interfacial bonding. Conclusion: In conclusion, alkali treatment is a potential method to improve the interfacial characteristics of bamboo fibre in unsaturated polyester. Recent patent suggested that coating with bacterial cellulose is a green technique for better interfacial bonding behaviour.

The application of natural fibers as reinforcement in polymer composites has been continuously growing during the last few decades. These composites find diverse applications in hostile environment where they are exposed to external attacks such as solid particle erosion. Also, in many respects, the mechanical properties of different polymer composites are their most important characteristics. Therefore, improvement of the erosion resistance and mechanical behavior of polymer composites are the prime requirements in their applications. Bamboo fiber which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for reinforcement in polymers. To this end, an attempt has been made in this paper not only to study the utilization potential of bamboo fiber in polymer composites but also to study the effect of various parameters on mechanical and erosion wear performance of bamboo fiber reinforced epoxy composites.

2 - Bio-based hybrid polymer composites: A sustainable high performance material

<div class="section abstract"><div class="htmlview paragraph">Natural fibers have been increasingly used in polymer composites during the last decade, and this has a significant impact on environmental implications. Natural fibers from lignocellulose materials have recently emerged in the form of fabric woven reinforced in polymer composites due to numerous applications, including structural and non-structural variants. One of the most promising materials for substituting synthetic polymeric materials by naturally available fiber reinforcements in polymer composites is woven fabric. Bamboo/Bamboo woven fabric encompasses bamboo yarn in both the warp and weft directions was chosen for this study. Bamboo/bamboo twill woven fabric acting as a reinforcement in the composites with epoxy resin as a bonding material using the compression moulding method of manufacturing. The mechanical characterization of twill woven fabric bamboo/bamboo reinforced composites was examined using five dissimilar fiber loading conditions (30:70, 35:65, 40:60, 45:55, and 50:50 wt.%) and mechanical parameters such as Tensile strength, Compression strength, Interlaminar shear stress and Impact strength were examined as per the ASTM standards. The study shows that the 45wt % of twill weave composites had a greater mechanical performance when compared to other wt % of composites. The findings revealed that the texture pattern of the fabric has a significant impact on the strength of fiber reinforced composites.</div></div>

Fiber reinforced polymer composite have acquired a dominant place in variety of applications because of higher specific strength and modulus, the plant based natural fiber are partially replacing currently used synthetic fiber as reinforcement for polymer composites. In this research work going to develop a new material which posses a strength to weight ratio that for exceed any of the present material. The hybrid composite sisal/hemp reinforced with epoxy matrix has been developed by compression moulding technique according to ASTM standards. Sodium hydroxide (NAOH) was used as alkali for treating the fibers. The amount of reinforcement was varied from 10% to 50% in steps of 10%. Prepared specimens were examined for mechanical properties such as tensile strength, flexural strength, and hardness. Hybrid composite with 40wt% sisal/hemp fiber were found to posses higher strength (tensile strength = 53.13Mpa and flexural strength = 82.07Mpa) among the fabricated hybrid composite specimens. Hardness value increases with increasing the fiber volume. Morphological examinations are carried out to analyze the interfacial characteristics, internal structure and fractured surfaces by using scanning electron microscope.

Recent advances in lignocellulosic fibers for developing sustainable composites: extraction, surface modification and characterization- A review.