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In an era of technological advancements, the quest for sustainable products has taken a center stage. The utilization of natural fiber reinforced polymer composites has become crucial in the manufacturing of eco‐friendly products due to their low cost, renewability, biodegradability, and comparable properties to synthetic composites. Coir‐based composites have been utilized in roofing, composite panels, furniture, and bio‐based insulation applications, providing enhanced strength and sustainability. In the current investigation, an exploratory data analysis (EDA) was conducted to understand the relationship between the various input variables and the flexural properties of short coir polymer composites (SCPCs). The data analysis revealed that manufacturing process had a significant impact on the flexural properties of SCPCs. Based on the insights gained from the EDA, an optimized Random Forest prediction model was developed to predict the flexural properties. Genetic algorithm approach for hyperparameter optimization led to lower objective loss in contrast to Bayesian optimized Random Forest model. The model's performance was subsequently evaluated through holdout validation, and the outcome demonstrated the model's proficiency in accurately predicting the properties. The developed model can be used as a tool for optimizing the design of SCPCs for specific applications, by predicting the flexural properties of the composites. Highlights: Flexural behavior of short coir polymer composites was analyzed and modeled.Manufacturing process has the highest impact on the flexural properties.Random forest model predicted the flexural properties with high accuracy.Genetic algorithm optimized model further enhanced the model performance.The developed framework provides insights into designing biocomposites. [ABSTRACT FROM AUTHOR]

Highlights Coir fiber (COIRF) reinforced glycidyl methacrylate (GMA) functionalized ethylene butyl acrylate (CF‐EBA) composites (COIRF/CF‐EBA) were processed by extrusion and injection molding. A good COIRF/CF‐EBA interfacial adhesion was indicated by Scanning Electron Microscopy (FE‐SEM). Fourier Transform Infra‐Red (FTIR) spectroscopy established this adhesion emerging from etherification and hydrogen bonding between the functional groups of CF‐EBA and of COIRF. The composites exhibited higher tensile properties than pristine CF‐EBA, and also exhibited increase in their tensile properties with increase in COIRF contents in them. The storage modulus and loss modulus of the composites also increased as the amount of COIRF in them increased, but the values of these properties decreased with increasing temperature. Thermal stability of the composites was observed to be intermediate between that of COIRF and CF‐EBA. Coir Fiber/Chemically Functionalized Ethylene Butylene Acrylate Composites. CF‐EBA/COIRF bonding by etherification and hydrogen bonding between them. The COIRF/CF‐EBA composites show higher properties than their CF‐EBA matrix. 30/70 COIRF/CF‐EBA composite showed the highest tensile strength (10.93 MPa). COIRF/CF‐EBA composite show thermal stability upto approx. 245°C. [ABSTRACT FROM AUTHOR]

The enhancement of the mechanical and thermal characteristics of 3D printed polylactic acid (PLA) composites reinforced by coir fiber powder (CFP) has been investigated by varying the weight percentage (wt%) of the reinforcement and annealing process. CFP/PLA composite filaments with CFP compositions of 0.1, 0.3, and 0.5 wt% were fabricated. These filaments were used to print CFP/PLA test specimens. The specimens were annealed at 90°C for 120 min in a hot air oven followed by cooling at room temperature. Mechanical, morphological, crystalline, and thermal characterizations were conducted on these specimens. The tensile and flexural strength of neat PLA were observed as 49.7 and 82.4 MPa which decreased by 6.4% and 8.13% respectively for printed composite specimens with 0.5 wt% CFP as reinforcement material. On the other hand, the annealed CFP/PLA composite specimen, with 0.1 wt% CFP as a reinforcement material, demonstrated higher tensile and flexural strength. Specifically, it exhibited a maximum tensile strength of 56.4 MPa and a maximum flexural strength of 92.9 MPa, which are 13.5% and 12.7% higher, respectively, than neat PLA. These strengths are 15.5% and 16.7% higher, respectively, than those of the unannealed CFP/PLA composite specimen with the same wt% of CFP reinforcement. The annealing process increased the crystallinity of composites by enhancing the crystallinity index (63%) and crystalline size (6.7 nm). The high thermal stability of composites (with a glass transition temperature of 256°C) makes them suitable for applications in food and medical packaging. Highlights: Enhancement of thermo‐mechanical characteristics of 3D printed bio‐composites.Annealing process improved mechanical features of 3D printed bio‐composites.Annealed composite with 0.1 wt% as reinforcement demonstrated better properties.SEM and XRD studies confirmed failure mechanisms and crystalline structure.Thermal and mechanical assets favor its utilization in food wrapping applications. [ABSTRACT FROM AUTHOR]

Nowadays, various types of biocomposites are being developed using different types of natural fibers and polymers to fulfill the requirement for sustainable products. Recently, the addition of fillers in biocomposites has been a useful approach to improve their performance and overwhelm their limitations. The hollow glass microspheres (HGMs) were uniformly distributed into epoxy using a magnetic stirrer and subsequently, a hand lay‐up technique was employed to produce the HGMs/coir/epoxy composites under a static loading condition. In the current study, the effect of varying weight percentages (i.e., 1, 3, and 5) of HGMs on the mechanical, dynamic mechanical, and thermal properties of coir/epoxy composites has been studied. Further, morphological analysis of fractured surfaces of samples was also performed. The results suggested that the addition of HGMs caused a significant improvement in the tensile and impact properties of the composites but could not extensively improve the flexural strength, thermal stability, storage modulus, and loss modulus. There was a significant improvement of 80.5% in tensile strength and 24.7% in impact strength of composites after the addition of 1 wt%. HGMs. Further, tensile and flexural moduli were found to be gradually improved with increased HGMs weight percentages in the composites. Highlights: Development of HGMs/coir/epoxy composites.Addition of HGMs increases tensile and impact strength of coir/epoxy composites.Microstructural analysis of HGMs/coir/epoxy composites. [ABSTRACT FROM AUTHOR]

This work aims to incorporate lignocellulosic coconut coir (CC) fillers into the HDPE matrix for domestic cloth clip product development where the strength is less significant. The structural, mechanical, and thermal properties of HDPE composites with varying weight fractions of CC fillers (10, 20 wt%) were investigated. The die for product development was designed through Pro‐E software and manufactured with relevant machining processes. The composites were fabricated through the injection molding technique as per ASTM standards. Using scanning electron microscopy (SEM) and energy dispersive X‐ray (EDX) analysis, the microstructure and various proportions of elements present in the composites were investigated. The presence of different functional groups and their vibrations were identified through the Fourier‐transform infrared spectroscopy (FTIR) technique. The experimental mechanical results reveal the positive effect of CC fillers in the HDPE matrix, and the results were a maximum of 20 wt% CC filler incorporation. The filler reinforcement has little effect on the thermal degradation behavior since the step of deterioration is not changed appreciably. Nevertheless, the initial degradation temperature was affected by the presence of CC fillers. Depolymerization and dehydration of diverse ingredients correspond to different endothermic peaks in the DSC curve. Based on the characterization results, the 20 wt% CC filled‐loaded partial eco‐composite was selected for cloth clip product development. [ABSTRACT FROM AUTHOR]

In this current research study, nine different combinations of coir, jute, and bamboo reinforced epoxy composites were fabricated using casting technique. These composites were employed to mechanical tests such as flexural and impact tests, and analyzed the thermal stability through Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). Moreover, the thermal conductivity and surface morphology was also studied for hybrid composites. The hybridization of more than one fiber with epoxy matrix resulted in better mechanical and thermal properties as compared to individual reinforcements, and this statement is agreed with the present research work as well as the research works reported in the literature. The hybrid composite with the maximum amount of jute fibers reinforcement with bamboo fiber (B2C0J8) exhibited maximum flexural and impact strengths of 92.521 MPa and 82.4 kJ/m2 respectively, which is due to the higher modulus and energy‐absorbing behavior of jute fibers, also it was an advantage of coir fibers absence having lower modulus and strength values. In thermal conductivity analysis, the marginal variations of values were observed with different volume fractions of fibers, and the maximum conductivity (0.317 W/m‐K) was obtained for B2C8J Composite having only coir and bamboo fiber reinforcements with epoxy matrix. The Thermogravimetric analysis results reveal that all nine types of hybrid composites possess nearly equal thermal stability, and slight variations in degradation temperatures were observed in the thermographs. The B2C1J7 hybrid composite was recommended for better mechanical and thermal properties, where it has 89.06 MPa of flexural strength, 78.6 kJ/m2 of impact strength, 0.233 W/m‐K of thermal conductivity and exhibited better surface morphology. [ABSTRACT FROM AUTHOR]

Physical, mechanical, and tribological properties of automotive brake friction materials were investigated to study the influence of various slag waste and coir fiber combinations. The friction composites were manufactured by mechanical mixing and compression molding at varying slag waste (45%, 50%, 55%, and 60%, by weight) and coir fiber (5%, 10%, 15%, and 20%, by weight) loading. The density, hardness, shear strength, and ash content decreased while porosity and compressibility of the composites increased for decreasing slag waste with a simultaneous increase in coir fiber content. The tribological properties of the manufactured composites were evaluated on a Krauss machine by following the ECE R‐90 standard. The highest friction (0.396), lowest fade (15.40%), and lowest friction fluctuations (0.101) were recorded for the composite having 60 wt% slag waste and 5 wt% coir fiber content. In contrast, recovery performance remains highest (131.80%) in the composite with 45 wt% slag waste and 20 wt% coir fiber content. Besides, the wear of the composites was found to increase with increased coir fiber content. Moreover, the composites' worn surfaces were studied using scanning electron microscopy to understand the mechanisms responsible for the surface damage and how slag waste and coir fiber combinations would affect such friction composite materials' friction and wear performance. [ABSTRACT FROM AUTHOR]

In the present research, the physical, mechanical, and thermal characteristics of bio and synthetic basalt fabric epoxy composites reinforced with coir microparticles and TiC nanofillers under before and after exposure of accelerated weathering were investigated. All the bio and synthetic epoxy hybrid composites were exposed to humidity, elevated temperature, and ultraviolet radiation. It has been examined that both bio and synthetic epoxy composites exhibited reduced mechanical characteristics after the exposure of accelerated weathering when compared with before exposure. The wettability experiment was performed from the contact angle evaluation method and found that all the fabricated samples before and after the exposure of accelerated weathering have contact angle value lower than 90° that is assigned with the hydrophilic surface characteristics of the laminate. The water absorption capacity showed that all the bio and synthetic epoxy composites reacted for water absorption up to 45 days and then endured constant in both conditions. After the exposure of accelerated weathering, epoxy hybrid composites absorbed more water than before exposure. The chemical modifications possessed on the surface were evaluated from Fourier transform infrared spectra. The intensity of hydroxyl and carbonyl functional groups of bio and synthetic epoxy hybrid composites decreased compared with the original samples, which tends to decrement in tensile, flexural, and impact characteristics of the laminate. The production of more fracture lines on the cross‐sectional surface of epoxy hybrid composites has been observed from scanning electron microscope micrographs after the exposure of accelerated weathering. The onset, end set, and glass transition temperature of bio and synthetic epoxy composites in the thermal examination were reduced after the disclosure of accelerated weathering for all fabricated specimens. The reason may be assigned to the weaker bonding between the coir microparticles and TiC nanofillers. The undesirable impact emerged from ultraviolet radiation, elevating the temperature and humidity. The test results showed that the accelerated weathering has negative impact on physicomechanical characteristics of bio/synthetic epoxy hybrid polymer composites. The overall thermal characteristics were not considerably affected with 570 h of the weathering exposure. [ABSTRACT FROM AUTHOR]

The present work's target is to study the impact of fly ash or TiC nanoparticles or both on the characteristics of coir fiber epoxy hybrid composites. Mechanical characteristics like tensile, flexural, inter‐laminar shear strength, impact strength, shore D hardness, and thermal stability or degradation characteristics were determined. The microstructure of the samples was observed from a scanning electron microscopy. It was observed that the addition of coir fiber, fly ash, and TiC nanoparticles in the epoxy polymer enhanced the mechanical and thermal characteristics of composites. It can be assigned to the better interaction and uniform distribution between the fillers and the epoxy polymer. Fillers acted a critical role in enhancing the characteristics of epoxy hybrid composites. Additionally, water absorption characteristics were also investigated for all specimens. A comparative examination was performed between various fabricated composite specimens. Results exhibited that, the water absorption of the composites improves considerably with the addition of reinforcements. Also, thermogravimetric analysis exhibited that the fabricated epoxy hybrid composites were stable thermally. [ABSTRACT FROM AUTHOR]

In this study, two different surface treatments were evaluated to improve the compatibility of coir fibers with poly(lactic acid). The chemical modifications were achieved by fiber surface treatment with a maleic anhydride grafted to poly(lactic acid) (MAPLA) solution or a poly(methyl vinyl ether‐alt‐maleic anhydride) (MA‐c‐PMVE) aqueous solution. The fibers were analyzed by attenuated total reflectance‐Fourier transform infrared to determine the type and level of surface modification. The biocomposites were compounded via extrusion and molded by injection. Mechanical testing showed increases in tensile modulus (around 16%) and flexural modulus (around 16%) for both treatments, but MA‐c‐PMVE (29%) was more effective than MAPLA (15%) in strength improvement. Finally, the surface treated fibers led to much lower biocomposites water absorption than untreated ones. POLYM. COMPOS., 40:2132–2141, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Microfibers were prepared from coir, an important lignocellulosic fiber, by chemico‐mechanical treatment. The microfibers with a diameter of 8–13 μm were incorporated in natural rubber and the resultant biocomposites were evaluated for the reinforcing effect of microfibers. Latex stage processing employed for composite preparation reduces fiber agglomeration and provide uniform dispersion of microfibers in the elastomer matrix. Microfiber/natural rubber composites were found to exhibit significant improvement in mechanical properties compared with unfilled and macrofiber filled composites. Microfibers showed higher thermal stability compared with untreated coir. However, degradation resistance of microfiber composites remain lower with respect to vulcanized natural rubber. POLYM. COMPOS., 40:414–423, 2019. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The surfaces of coir fiber (CF) and coconut shell powder (CSP) were modified by alkali and silane treatment respectively to investigate the consequent effects on reinforcement of vinyl ester (VE) composites. Mono‐composites of VE with surface treated CFs and CSP as well as their hybrid composites with as‐received aramid fibers (AFs) have been prepared by hand layup followed by compression molding methods. The effectiveness of surface treated reinforcements in improving the mechanical properties of the composites was demonstrated. Significant differences between VE mono‐composites and their hybrid reinforcements on hardness and tensile properties of VE were observed, while no improvement in the above‐mentioned properties except for Young's modulus was observed for hybrid composite with AFs. It was also observed that surface treated CFs and CSP reinforced VE composites exhibited better hardness and tensile properties. SEM imaging confirmed decreased fiber pull‐out for VE reinforced with alkali treated CFs because of the enhanced adhesion between the CFs and the VE matrix. Flexural properties of all the composites decreased. This study has proved that the mechanical properties of hybrid VE composites can be enhanced by modifying the reinforcements by alkali and silane into their formulations. These results have been explained on the basis of structure and morphology in terms of fractography of VE composites. Furthermore, this study demonstrates that alkali treatment is a promising technique for improving the mechanical properties such as hardness and tensile properties of CF reinforced hybrid polymer matrix composites. POLYM. COMPOS., 39:4542–4550, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Untreated sisal and coir fibers (USF and UCF), alkali‐treated sisal and coir fibers (ASF and ACF), and alkali‐treated sisal/coir hybrid fibers (ASF/ACF) reinforced polylactide (PLA) composites were prepared by compression molding technique. The materials were characterized in terms of tensile, flexural, and impact properties. While all mechanical tests showed that the composites reinforced by alkali‐treated fibers could withstand more fracture strain than untreated fibers reinforced composites which could be attributed to the improved interfacial adhesion between alkali‐treated fibers and matrix related to the remove of lignin, hemicellulose and pectin by the alkali treatment, the addition of ACF in PLA/ASF composites improved the impact strength of PLA/ASF/ACF composites and showed a positive effect. More fibers tended to be torn apart or fractured, but less pulled out with the increase of coir fiber content. Compared to other composites, the ASF/ACF‐reinforced PLA composites offered superior mechanical properties when the ratio of sisal to coir was 7:3. POLYM. COMPOS., 39:E188–E199, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Coir pith/epoxy, nylon/epoxy, and coir pith/nylon/epoxy composites were prepared keeping the coir pith content at 65%. Two series of the above composites, one with chemically treated coir pith and another without chemically treated coir pith were fabricated. The Dynamic mechanical properties of composites were evaluated with respect to type of composites and treatment. Storage modulus was found to improve with hybridization and chemical treatment. Meanwhile Tan δ of composites were found to be decreased with hybridization and chemical treatment. Compressive strength of composites with chemically treated coir pith was found to be higher than other composite samples and this has been justified in terms of increased crystallinity of coir pith on treatment. The studies on sea water ageing of composites also indicated improved stability of composites with hybridization and chemical treatment. The dielectric properties of the boards were also evaluated in this investigation and the boards were found to show lower dielectric constant with chemical treatment of coir pith. POLYM. COMPOS., 38:1671-1679, 2017. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Development of natural fiber composites with thermoplastics and thermosets finds applications in various fields, from agriculture to automotive. It can reduce the dependency on petroleum resources which causes several environmental problems. Natural fibers are renewable and biodegradable that reduces carbon footprint to the environment. Coir fibers are natural fibers used in the development of composites offers comparable properties with other mineral fillers. This article reviews different methods of coir fiber modification include alkali treatment, silane treatment, hydrogen peroxide treatment, sodium hypochlorite treatment, sodium periodate treatment coupled with paminophenol and urea, treatment with benzene diazonium salt and maleated coupling agent. It also reviews composites of coir fiber with thermoplastic, rubber and thermoset plastics. Hybrid composites based on coir fiber are also being discussed. Thermoplastic composites such as biodegradable (PLA, PBS) and petroleum-based polymers (PE, PP) and thermoset polymers include polyurethane, epoxy and polyester based composites also reviewed. Degradation and biodegradation studies were reviewed in the case of biodegradable polymers. Hybrid fibers of coir with other natural and mineral fibers have recently been used in composite industry has also been reviewed. All these composites show better properties. It can be used in different applications in the field of automobile, building and construction, consumer products and furniture. [ABSTRACT FROM AUTHOR]

The aim of the work was to develop environmental friendly coir pith-based composites with a good balance of mechanical properties. Multilayered coir pith/nylon fabric/epoxy hybrid composites were fabricated by the hand lay-up technique followed by compression molding. A set of composites of same composition having chemically treated coir pith was also prepared. Mechanical properties of composites such as tensile strength, impact strength, flexural strength, hardness, and abrasion resistance were evaluated. The hybridization with nylon fabric and the chemical treatment of coir pith enhances the mechanical properties of composites. Chemical resistance and void content of the composites were also determined and reported. A comparative evaluation is done between composites having chemically treated coir pith and untreated coir pith. Coir pith was subjected to different treatments such as sodium hydroxide treatment followed by sulfuric acid, dicumyl peroxide, sodium hypochlorite, acrylic acid, and acetic acid. POLYM. COMPOS., 37:649-657, 2016. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

This work is aimed at determining the possibility of using crab carapace materials as reinforcing fillers in the coir fiber reinforced polyester composite. The sample preparation was carried out with three levels of fiber length (10, 30, & 50 mm), fiber weight content (10, 25, and 40%), and additive weight content (2, 4, and 6%). The composite sheets were prepared by impregnating crab carapace additive obtained from crab shell with coir fiber reinforced polyester composite using compression molding machine. The tensile, flexural, and impact strength of the composites were determined as per ASTM standards and regression models were developed to predict the mechanical behaviors of the composites using statistical technique. The fabrication parameters considered in this investigation has significantly contributed toward the mechanical properties of the composites. The developed regression models were optimized to obtain the maximum values of mechanical properties using single objective genetic algorithm and multiobjective lexicographic method in this investigation. POLYM. COMPOS., 37:844-853, 2016. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]