Coir Fiber Composites Research Articles

Enhanced Thermal Performance of Alkali-Treated Bamboo, Coir, and Date Palm Fiber Composites for Solar Distillation Applications

Enhanced Thermal Performance of Alkali-Treated Bamboo, Coir, and Date Palm Fiber Composites for Solar Distillation Applications

Improvement of mechanical and thermal expansion properties of pectinase treatment plant fiber reinforced starch/PBAT composites

AbstractThis study discussed the impact of pectinase treatment on the properties of starch/PBAT composite, using two types of plant fibers such as coconut coir and bamboo fibers. The fibers underwent pretreatment with pectinase assisted by ultrasonics, and the composite was subsequently produced through hot pressing. The research focused on evaluating the thermal properties, mechanical properties, moisture absorption properties, and microstructure of the resulting composites. The findings revealed that the inclusion of pectinase‐treated plant fibers significantly enhanced the composite's strength. In particular, the bending strength of the composite with 15 wt% bamboo fibers exhibited the highest improvement, registering a 65% increase compared to the composite without added fibers. Additionally, the linear expansion coefficient of the plant fiber composite treated with pectinase was notably lower than that without added fibers. Among these, the linear expansion coefficient of the 15 wt% coir fiber composite decreased by 73.4% in the temperature range of 40–80°C compared to the composite without added fibers. The observed effects were attributed to the pectinase treatment, which proved effective in disrupting the network structure of cell walls, eliminating pectin components from fibers, and facilitating enhanced interaction between the fillers and the polymer matrix.Highlights The inclusion of fibers significantly enhanced the composite's strength. 10 wt% of bamboo fibers had a greater impact on the composite's strength than coir fiber. The linear expansion coefficient of the plant fiber composite decreased. The composite with 5 wt% bamboo fiber demonstrated excellent moisture resistance. The pectinase treatment enhanced interaction between fillers and matrix.

Synergistic Enhancement of the Mechanical Properties of Epoxy-Based Coir Fiber Composites through Alkaline Treatment and Nanoclay Reinforcement

This study explores the synergistic effects of incorporating coir fibers and nanoclay into epoxy resin composites. Coir, a renewable and cost-effective natural fiber, undergoes an alkaline treatment to influence its ability to form strong interfacial bonding with the epoxy matrix. To further enhance the mechanical properties of the composite, montmorillonite nanoclay, surface-modified with aminopropyltriethoxysilane and octadecyl amine, is introduced. The research investigates different combinations of coir fiber content (20, 30, and 40 wt%) and nanoclay loading (0, 2, and 4 wt%) with epoxy resin. The composites are fabricated through an open molding process, and the mechanical properties are evaluated using tensile and flexural tests according to the ASTM D638 and D7264 standards, respectively. The tensile and flexural strengths of the 40 wt% coir fiber-reinforced epoxy composite are found to be 77.99 MPa and 136.13 MPa, which are 44% and 23% greater than pure epoxy, respectively. Furthermore, the strengths displayed a 23% improvement in tensile strength with 4 wt% and a 31.4% improvement in flexural strength with 2 wt% nanoclay as additional reinforcement. Scanning electron microscopy is employed for fractographic analysis of the fractured specimens from the tensile test. The study underscores the importance of understanding the interplay between natural fibers, nanoclay, and epoxy resin for optimizing the composite’s performance in real-world applications.

Pembuatan Komposit dari Serat Sabut Kelapa dan Resin Polyester sebagai Material untuk Helm

A composite is a material made from a combination of two or more materials. The purpose of this study was to determine the feasibility of a reinforced configuration of coco fiber. The method of making this composite used the hand lay-up method or an open mold process. The test results of the coir fiber composite had an actual density value of 60% fiber and 40% resin composition of 1.19 g/cm3 and the lowest porosity value of 0.58% in the random arrangement fiber impact test specimen. The best value of impact toughness was found in the composition of 50% fiber and 50% resin of 271,311.29 J/m2 in straight fiber specimens with ductile mechanical properties. This value was much higher than the impact toughness of SNI 18111-2007 helmet material of 9,720 J/m2. Based on these results, the composite material, polyester resin reinforced with coconut fiber, is suitable as an alternative material in the manufacture of SNI helmets when viewed from the value of impact toughness and tensile strength.

Water aging effects on the flexural properties of fully biobased coir fiber composites

AbstractThis work describes the flexural behavior of biocomposites composed of a polyurethane matrix derived from castor oil plants and coir fibers. A statistical design is performed to identify the effects of fiber alkaline treatment and aging on the flexural modulus and strength of the composites. Physical tests and failure analyses are carried out to better assess their mechanical performance. A second experiment at 100% relative humidity is performed on treated fiber composites to compare with those obtained by immersion in water. The flexural modulus of the composites is not significantly affected by the fiber alkali treatment, while the strength is reduced by 35.17% when treated fibers are considered. Increasing the exposure time of composites under both aging conditions progressively reduces their flexural properties. The aging process of biocomposites in an environment with 100% relative humidity takes twice as long to reduce to the same flexural properties as those aged in water.Highlights Composites made with treated fibers showed higher apparent density and lower porosity. Water aging reduces flexural modulus and strength of biobased coir composites. The bending properties are strongly dominated by the properties of biobased polymer. 100% relative humidity takes twice as long to reduce to the flexural properties as those aged in water. Untreated coir fibers achieve superior bending properties under moisture aging.

The effect of low viscous coir fiber resin composite immersion time on composition dissolution

Background: E glass fiber dental is a fiber that is often used in dentistry. The availability of E glass fiber in Indonesia is still very limited. Various types of non-dental glass fiber materials are found in the market as engineering materials with relatively cheap prices so that they are expected to be used as an alternative to E glass fiber dental, which one of is coconut fiber. The composition of non-dental glass fiber is almost the same as that of dental E glass fiber. The composition affects the mechanical properties and chemical properties of the fiber. Glass fiber compositions such as Na2O and K2O will increase water resistance. 
 Method: This study was conducted using a post test only control group design. The material used in this study was a composite of coconut coir fiber. The subjects of the coco fiber composite were divided into 4 groups for solubility test based on ISO 4049. The results obtained were analyzed using one-way ANOVA (p = 0.000). The results showed the lowest mean component solubility (%) was in the coconut fiber composite group A (0.476±0.03) and the highest yield was in the coco coir fiber composite D (0.6±0.01). 
 Results: The results of the one-way ANOVA test showed a significant difference in the coco fiber composite in the solubility of the components (p

Dynamic mechanical behavior of coir fiber composite using Taguchi’s parametric design approach

Dynamic mechanical behavior of coir fiber composite using Taguchi’s parametric design approach

Data-driven analysis and prediction of tensile behavior of coir-based composites

Coconut husk-derived coir fiber composites, an eco-friendly alternative to conventional polymer composites, are being considered as a viable substitute for non-structural applications. The current research endeavor aims to develop a framework for analyzing and predicting the tensile properties of short coir-based composites (SCBCs) using neural networks. The effect of parameters such as fiber treatment, fiber content, fiber aspect ratio, manufacturing process, and matrix type on the tensile properties of SCBCs has been considered. The standard performance metrics assessed the feasibility of the developed model. The coefficient of determination (R2) of 0.9661 and 0.9816 was obtained for the tensile strength and tensile modulus prediction model, respectively.

Properties of coir fibre/polylactic acid composites based on amylase processing

The objective of this study was to investigate the impact of amylase treatment on the properties of polylactic acid (PLA) composite, using coir fiber. The coir fiber was treated with a 5% amylase solution and the modified coir/PLA composite was produced via hot pressing. The mechanical properties, water absorption and moisture absorption properties, and microstructure of the composites were analyzed. The findings revealed that the addition of amylase-treated coir fiber significantly enhanced the strength and stiffness of the composite. Specifically, the tensile strength, bending strength, and impact strength increased by 5 times, 3.6 times, and 2 times, respectively. Furthermore, the composite’s fracture mode changed from pure tensile to shear and tensile mixed fracture. The water absorption performance of the coir fiber composite increased by an average of 29.58% after amylase treatment, which improved the composite’s ability to withstand humidity. Lastly, the microstructure of the composite material was discussed. The enzyme decomposed the starch in the fiber, removing impurities and increasing the surface area, providing more sites for binding to polylactic acid and improving the interface compatibility between the two substances. The results are significant for developing new and sustainable bio-based composites.

Sintesis Biokomposit Serat Sabut Kelapa dan Resin Poliester dengan Alkalisasi KOH Menggunakan Metode Hand Lay-Up

Development of bio-composite materials is growing rapidly, as these materials are light, strength, and have good resistance to corrosion. Moreover, bio-composite is one of many options to utilize agricultural waste. Polyester resin and coconut coir fiber can be utilized as matrix and filler for bio-composites. Alkalization is a method to obtain high quality cellulose from natural materials. The objective of this study is to examine the effect of KOH concentration on tensile strength and hardness of coconut coir fiber and polyester resin composite. The composite was successfully synthesized using hand lay-up method. Tensile strength and hardness tests were conducted to examine the composite’s physical properties, meanwhile Fourier Transform Infrared was employed to examine the material’s functional group. Bio-composite with coconut coir fiber and polyester ratio=40:60 yielded the highest tensile strength of 6.04 MPa. Furthermore, the composites that are synthesized with alkalization using KOH concentration of 5%wt, 10%wt, 15%wt, and no alkalization produced tensile strength 5.29, 6.92, 3.50, and 3.50 MPa respectively. In addition, the composites with KOH concentration of 5%wt, 10%wt, 15%wt, and no alkalization generated hardness 70, 73, 73, and 72 Shore D respectively. It can be concluded that the higher coconut coir fiber ratio, the higher the bio-composite’s tensile strength.

Mechanical Behaviour and Impact of Various Fibres Embedded with Eggshell Powder Epoxy Resin Biocomposite.

Natural fiber composites are becoming an alternate material to synthetic fiber composites, and the use of eggshell bio-filler has been explored in polymer composites as environmental protection. Jute, coir, and sisal fibers were utilized in this research to make composites out of natural fibers. Polymer composites were made using epoxy resin with different amounts of eggshell powder (ESP) as fillers (2%, 4%, 6%, 8%, and 10% of weight). The mechanical and biodegradability properties of the synthesized composites were investigated. The testing results showed that composites with an optimum percentage of 6% ESP as filler improved mechanical characteristics significantly in all three fiber composites. Among the three fibers, coir fiber with 6% ESP added showed a substantial increase in tensile, flexural, impact, and hardness strength properties by 34.64%, 48.50%, 33.33%, and 35.03%, respectively. In addition, the percentage weight loss of coir fiber composites at 9 weeks is noteworthy in terms of biodegradability testing. As a result, epoxy composites containing eggshell fillers could be employed in applications requiring better tensile, flexural, impact, and hardness strength.

Experimental and numerical analysis of different natural fiber polymer composite

ABSTRACT In this study, different combinations of Hemp, Bamboo and Coir fiber are considered as reinforcement materials, while AW106 epoxy resin and HV953 are used as hardeners. The composite lamina was prepared and tested using the hand layup technique with short and random fibers. The tensile and compressive test performed for the analysis of mechanical properties shows that 15% hemp fiber composite is better than bamboo and coir fiber composite. With the increase in fiber volume fraction mechanical properties increases up to a certain limit and a further increase in fiber volume ratio shows adverse effect. Numerical modeling of 15% hemp fiber composite, 15% bamboo fiber composite and 15% coir fiber composite has been done for the calculation of natural frequency and damping factor of natural fiber composite. Numerical modelling was performed using ANSYS 2021 R1 and the specimen was considered in the form of a cantilever beam with a size 200 mm × 20 mm × 4 mm. The damping factor was calculated with the help of the half-power bandwidth method. Numerical analysis reveals that natural frequency and damping values of hemp fiber composite are better than bamboo and coir fiber composite. The worst results were obtained for coir fiber composite. The nondimensional frequency response of hemp fiber composite is better than bamboo and coir fiber composite.

Development of Recycled Natural Fiber Based Composite Material by Hand Lay-Up Process and Analysis of Its Acoustic & Physical Properties

ABSTRACT This research mainly characterizes a unique property of both jute and coir fiber composites. The target of the paper was to justify that unique characteristic, which featured to be the sound absorption quality of those two fiber composites. The composites involved jute and coir fibers as reinforcement and epoxy resin as polymer matrix. The analysis of the binding capability of epoxy resin and its ability to provide net shape to the composites was also an important concern for this paper. Composites of both 100% jute and coir fiber and hybrid composites of different compositions of both fibers were the elements which had gone through the sound absorption test. The proper identification of the chemical composition of the fibers and the realization of the effect of silica gel coating applied on two of the pretreated fiber samples were also some of the distinctive facts and FTIR was performed to examine that. The strength of the composites was also observed. The outcome of the sound absorption test included that, the value of the sound absorption co-efficient changed with the variety in percentage of the fibers present. There also lied a significant difference in sound absorption quality of both the pure fiber composites.

The improvement of physicomechanical, flame retardant, and thermal properties of lignocellulosic material filled polymer composites

In this study, the effects of alkali and silane coupling agents and coir fiber (CF) loading on the fundamental properties of the CF-filled polypropylene (PP) composites were investigated. Mechanical properties of the PP/CF composites, such as tensile strength, tensile modulus, impact strength, and water absorption were increased by the increase of the CF loading. The inclusion of 3-aminopropyl trimethoxy silane (ATS) and tetramethoxy orthosilicate (TOS) after the alkali pretreatment for the CF increased all the mechanical properties and water desorption of the resulting composites. This trend was more evident with the increase in CF loading. The best results were obtained for PP/TOS composites as compared to other composites. SEM images of fractured samples show improved adhesion between CF and PP matrix after treatment with ATS and TOS. The horizontal rate of combustion is significantly reduced with the inclusion of Mg(OH)2 in PP/ATS and PP/TOS composites. DSC results show improved crystallization temperature, melting temperature, and melting enthalpy as compared with virgin PP. The addition of ATS and TOS after the alkali pretreatment improved the thermal stability of the resultant composites. TOS-modified CF composites showed better resistance than ATS-modified CF composites in water medium.

Mechanical Properties and Thermal Analysis of Salago and Coir Hybrid Fiber Reinforced Epoxy Resin Composites

The utilization of natural fibers in composites continues to increase due to their advantages over the synthetic fiber materials especially in terms of environmental impact and costs. One of the techniques that can be used to further enhance the properties of these natural fiber reinforced composites is through fiber hybridization. In this study, salago and coir fibers were reinforced in the epoxy resin to form a new hybrid composite. The salago to coir fiber weight ratios considered in the fiber hybridization were 3:1, 1:1 and 1:3. The performance of these hybrid fiber composites were compared to pure coir fiber composite and salago fiber composite in terms of impact strength, tensile properties and flexural properties. Among the hybrid fiber composites, the fiber weight ratio of 3:1 has the highest tensile strength (33.8 MPa), tensile modulus (3.57 GPa), flexural strength (44.2 MPa) and impact strength (42.3 J/m). It was found out that the addition of coir to this hybrid fiber composite improves the tensile strength by about 21.1 % as compared to the salago fiber composite. On the other hand, the addition of salago fiber to this hybrid fiber composite resulted to a higher tensile modulus (43.4 %) and impact strength (25.5 %) than the coir fiber composite. Moreover, the thermal analysis of the composites revealed a peak degradation temperature at around 370 °C which is associated to the decomposition of cellulose, hemicellulose and epoxy resin.

The effect of post-curing temperature on mechanical properties of coconut coir fiber reinforced polyester composite

This study used post-curing training as a method of strengthening. The smoking process was a process carried out in the form of heating the specimen at a certain temperature to improve the properties possessed by the composite. The purpose of this study was to study the effect of post-curing temperature on the impact strength of coconut coir fiber composites with temperature variations of 600ºC, 700ºC, 800ºC, 900ºC, 1000ºC. Specimens were prepared using a mixing method for mixing ingredients and a hand lay-up where in the composite volume fraction is prepared according to each specimen, which is 70% polyester and 30% coconut coir fiber. Each specimen is heated for 60 minutes in a conventional oven. Average impact strength and impact energy per unit area increases with the increase in post-curing temperature due to the fact that the movement of composites as well as the reduction of holes in the composites and adhesion to one another (suturing) can improve mechanical testing. The highest strength values obtained in the specimen with an increase in T = 100°C, ie 18,509 J for the average impact energy and 0,1434 J/mm2 for impact energy per unit area average.

Polyolefin Based Copolymers as Matrix Component in Coir Fiber Reinforced Composites

Natural fiber reinforced polymer composites have attracted much attention in global market as they possess much advantageous characteristics over conventional composite materials in terms of eco-friendliness, light weight, low cost, good mechanical properties and biodegradability. Among natural fibers, the surface properties of coir fiber can be easily improved when the fiber is reinforced with polymer matrix. Therefore, the aim of the present investigation is to develop a coir fiber composite reinforced with polyolefin based copolymers (PCs) and investigate the influence of coir fiber loading on mechanical as well as on water absorption behavior of the composites. Three types of PCs were synthesized using different controlled radical polymerizations (CRP) techniques and used as matrix in composite preparation. Poly(ethylene-co-butyl methacrylate) synthesized via dual concurrent atom transfer radical polymerization (ATRP)-reversible addition fragmentation chain transfer (RAFT) polymerization as well as RAFT mediated miniemulsion polymerization and poly(1-octene-co-butyl methacrylate) synthesized via RAFT polymerization were used as matrix component to prepare the composite materials. The performance evaluation of these PCs in the prepared composites was also compared. The composites were prepared using compression moulding method by reinforcing with 65, 70, 75 and 80 wt. % coirfiber loading. Analysis by universal testing machine (UTM) showed that the tensile strength and flexural strength of composites were decreased with increase in the fiber loading. Highest tensile as well as flexural strength was observed for 65 wt. % coir fiber loading. Among the three types of PCs matrixes, poly(ethylene-co-butyl mehacrylate) synthesized by RAFT mediated miniemulsion polymerization showed highest tensile and flexural strengths in the prepared composite. PCs reinforced coir fiber composites showed the potential advantage over coir fiber composites with commercial Araldite 506 resin as matrix component in terms of tensile as well as flexural properties. The morphological study by scanning electron microscopy (SEM) analysis confirmed the good adhesion between the PCs matrixes and the coir fibers in the prepared composites. X-ray photoelectron spectroscopy (XPS) analysis demonstrated significant changes occurred on the surface of coir fiber due to reinforcement of PCs matrixes and X-ray diffraction studies showed the amorphous natures of the composites without any crystallinity. Thermogravimetric analysis results revealed that due to penetration of PCs matrix into the coir fiber, the thermal stability of composites were significantly increased. Furthermore, water absorption properties of composites were also investigated. Based on these results the synthesized PCs/coir composite materials are found to be suitable for its use as hardboards and in different household furniture materials.

Eco-friendly Sandwich Panel Based on Recycled Bottle Caps Core and Natural Fibre Composite Facings

This is the first attempt to combine disposed bottle caps and natural fibres into sandwich panels. A full factorial design is performed to identify the effects of the skin type (aluminium or coir fibre reinforced laminates) and bottle cap core packing (cubic and orthotropic) on the mechanical properties of the proposed panels. The coir fibre composite skin provides maximum core shear strength, 29 % higher than the aluminium-based panels, in cubic packing, while the flexural modulus is reduced by 45 %. An interlocking effect between the skin and the core is evidenced when coir fibre composites are used. In addition, the cubic cell packing increases the specific mechanical properties, even though with a higher density. The results highlight a promising association of green components and plastic bottle caps for secondary structural applications.

Statistical analysis and investigation of tensile test data of coir composites reinforced with graphene, epoxy and carbon fibre

A successful attempt has been made to develop coir fibre composites reinforced with graphene, epoxy and carbon fibre. The carbon fibres were arranged in an intercalated manner, which is similar to the coir fibres. The percentage composition of graphene was varied as 1, 2, 4 and 6% by weight of the holding matrix. Suitable surface modifications were done by treating natural fibres by 5% NaOH and 0.3% KMnO4 for better adhesion of fibre and epoxy resin. Sonication and cetyl trimethyl ammonium bromide treatments were also done to achieve the fine scattering of graphene in the epoxy matrix in order to achieve better mechanical behaviour. Moulds were made as per D638 American Society for Testing and Materials (ASTM) standards. The treated fibres were then arranged in the mould by the conventional hand layup technique. Tensile testing was carried out to determine the mechanical properties of the composites. Two-way analysis of variance was used as a statistical tool to find the effect of parameters such as ‘Percentage composition of graphene’ and ‘Type of mould’ on the modulus of the composites. Fourier transform infrared spectroscopy was conducted to determine the interferential adhesion and homogeneous distribution of fibres in the composite matrix. At last, field emission scanning electron microscopy analyses were also done to the specimens before and after tensile testing to determine the morphology of different entities present in the composites.

Improvement of Mechanical Properties of Coir/Epoxy Composites through Hybridization with Sisal and Palmyra Palm Fibers

ABSTRACT In the present work, an attempt was made to improve the mechanical properties of the coir fiber reinforced epoxy composites through addition of high strength sisal and palmyra palm fibers. The hybrid composites were fabricated using compression molding technique by maintaining the volume fraction of fiber to matrix as 40:60. In the hybrid composites, the volume fraction of coir was maintained as 20%, while the volume fraction of other fibers was varied from 5% to 15%. The mechanical properties of the hybrid composites were investigated as a function of fiber volume fraction of sisal and palmyra palm fibers. The outcomes revealed that the hybrid composite have higher mechanical properties than the coir fiber composites due to synergistic effect of reinforcements. Furthermore, the morphological studies were carried out on the mechanical tested samples to predict the failure mechanisms.