Bio Epoxy Research Articles

Thermo‐mechanical performance of oil palm/bamboo fiber reinforced bio epoxy hybrid composites

AbstractThe aim of this work to fabricate bamboo (B)/oil palm (O) fibers based biocomposites to assess mechanical, thermal and morphological properties. Flexural strength and modulus of hybrid biocomposite (7B:3O) exhibited a higher value (71.18 MPa and 5.24GPa) respectively among all biocomposite samples. On the other hand, pure biocomposite (B) showed a higher impact strength value (6977.8 J/m2) compared to other biocomposites. The results of TGA showed that thermal stability was observed significantly for hybrid biocomposites compared to other samples. In addition, the maximum decomposition temperature values were displayed in the hybrid biocomposite (5B5O), which was 377.82°C. Through DMA, it was likely to find the storage modulus curves (E′), loss modulus (E″) and damping factor (tan δ) for the biocomposites. The E′ showed an increase in the (3736.84 MPa) contrasted to other corresponding samples which were 3121.81 MPa, and 3209.67 MPa for 3B7O MPa and 5B5O samples, respectively. Overall, the results of DMA displayed an enhancement in the storage modulus (E′) in terms of the hybrid biocomposites representing greater stiffness and lower damping factor. SEM micrographs were utilized to understand the fiber bonding and fiber adhesion with the epoxy matrix. Furthermore, it confirmed SEM results that hybrid natural fibers enhance the complete characterisations of bio‐epoxy materials. Additionally, SEM images of the tensile fracture surfaces discovered voids and cracks. Finally, it can be concluded that the selection for the developed hybrid biocomposites provides excellent and economical lightweight biomaterials for automotive, aerospace, contractions and building components.Highlights Green hybrid biocomposites by oil palm/bamboo fiber/bioepoxy resin. Mechanical, thermal, DMA of hybrid composites carried out. Hybrid biocomposite(7B:3O) exhibited higher flexural strength value (71.18 MPa). TGA showed that the biocomposites are thermally further stable. DMA displayed an enhancement in the storage modulus (E′).

Experimental Investigation of Low-Cost Bamboo Composite (LCBC) Slender Structural Columns in Compression

This paper experimentally investigates the behavior of innovative sustainable Low-Cost Bamboo Composite (LCBC) structural columns under compressive loading. The LCBC columns are manufactured from bamboo culms in combination with bio-based resins to form composite structural columns. Different LCBC cross-sectional configurations are investigated in this study, including the Russian doll (RD), Big Russian doll (BRD), Hawser (HAW), and Scrimber (SCR). Two bio-based resins, including one bio-epoxies and one furan-based resin, in addition to a soft bio-based filler and a synthetic epoxy resin, are applied. The bamboo species used as the cast-in-place giant bamboo for all configurations include Moso, Guadua, and Tali. Slender LCBC columns showed maximum stress equal to 60 MPa at failure. The study found that the samples with bio-epoxy resin (BE2) exhibited enhanced material stiffness when compared to synthetic epoxy (EPX) and furan-based resin (PF1), while PF1 specimens demonstrated increased ductility. Among the specimens with Moso bamboo and BE2 resin, those with SCR and HAW configurations achieved the highest compressive strengths.

Sandwich structures in bio-composite material for sustainable acoustic solutions

The use of bio-based materials in acoustic applications has gained a lot of attention recently as a functional and environmentally friendly alternative for synthetic materials. This is because conventional synthetic fibers have a significant impact on the environment and the health risks of people. The focus is now on developing composite systems that minimize environmental harm by using energy and materials more efficiently, and by substituting synthetic or petroleum-based materials with more sustainable options, such as natural fibers. These natural fibers are favoured for their biodegradability, sustainability, and widespread availability, earning them the label of "green materials." Thus, this paper aims to investigate the soundproofing capabilities of a novel sandwich structure composed of hemp fibers and bio-epoxy resin, aiming to broaden the application field of natural fiber composite materials.

Enhancing mechanical properties of natural waste‐based composites for automobile and plastic industry

AbstractNatural fiber composites are a renewable and environmentally friendly alternative to conventional synthetic materials that combine the biodegradability and essential durability of natural fibers with adaptability. Improved adhesion between fibers and matrix can be accomplished by comparing surface treatments applied to sugarcane, water hyacinth, and banana plant wastes. This will allow us to produce composite materials that are more durable and sustainable. To study the mechanical and morphological characteristics of the composites, two surface treatments were applied: gamma radiation at a dose of 1, 2, 3, 4 and 5 kGy and alkali treatment at a concentration of 5, 10, and 15%. The study revealed that with the increasing treatment of alkali solution, improvements in the composite's mechanical characteristics whereas gamma irradiation treatment enhanced the mechanical properties to a certain extent (2 kGy) after that the mechanical traits dwindled significantly. SEM, XRD, and FTIR analysis of the developed composite samples also revealed the reasons for the improvements in mechanical properties after alkali and gamma radiation treatments. As an ecofriendly and lightweight substitute for conventional materials, bio epoxy composites reinforced with natural fibers can be used for car interior panels, eco‐friendly furniture and as a replacement for any plasticware offering eco‐sustainability for contemporary living space.Highlights Natural fiber composites offer a renewable and eco‐friendly alternative to synthetic materials, combining biodegradability with durability. Surface treatments like gamma radiation and alkali treatment enhance composite's mechanical properties. Higher concentrations of alkali treatment improve mechanical characteristics, while gamma irradiation peaks at 2 kGy. Surface treatments offer promising avenues for advancing environmentally friendly materials, contributing to sustainable innovations in material science.

Effect of kenaf fibre loading on thermal and dynamic mechanical properties of bio epoxy composites

Effect of kenaf fibre loading on thermal and dynamic mechanical properties of bio epoxy composites

The Effect of Silanes Treatments on Thermal and Mechanical Properties of Nettle Fibre/Bio Epoxy Composites

ABSTRACT Obtaining suitable reinforcement of the polymer matrix depends largely on the appropriate connection at the fiber/polymer interface. Therefore, the main aim of the research was to assess the impact of silanization treatment of Himalayan nettle fibers on the properties of bio epoxy composites. Two types of silanes with different functional groups were used: 3-chloropropylmethyldimethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane at concentrations of 1 and 2%. The effectiveness of the fiber silanization process was confirmed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). It was found that treatment with silane with amine groups provided more effective adhesion between the fiber and the epoxy matrix than treatment with silane with chlorine groups. In addition, the thermal stability, impact strength, bending strength, impact resistance, density and water absorption of the composites were determined. It should be emphasized that silane treatment had a positive effect on the impact strength, impact resistance and flexural modulus of the tested layered composites.

Recyclable Curcumin-Based Bioepoxy Resin with On-Demand Chemical Cleavability.

We synthesized a novel curcumin-based bioepoxy resin by introducing epichlorohydrin (ECH) into the hydroxyl groups of curcumin and analyzed it using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The epoxy equivalent weight (EEW) was determined based on a reaction with sodium hydroxide (NaOH) through titration, and the actual curing process was conducted after exploring the optimal conditions using an amine-based curing agent through dynamic scanning in differential scanning calorimetry (DSC) and isotherm analysis. The cured epoxy resin had a tensile strength, Young's modulus, and glass transition temperature (Tg) of 33 MPa, 1.4 GPa, and 86 °C, respectively. Interestingly, the diunsaturated ketone contained in the epoxy resin showed on-demand chemical cleavability, in that it had been decomposed into an aldehyde and ketone only after having been converted to a hydroxyl ketone through an oxidation reaction. The results of this study can significantly contribute to improving the eco-friendliness and recyclability of epoxy resins used in fields requiring long-term stability and chemical resistance.

Valorization of purified agricultural brown eggshell by-product as filler in bio-epoxy composites

This study presents tensile, flexural and water absorption properties of composites made from bio-epoxy resin containing brown eggshell (with membrane), purified brown eggshell (without membrane) and mineral limestone at three filler levels of 5, 10 and 20 wt%. Composites were made by an open silicone mold casting method. Fourier transform infrared (FTIR) spectroscopy was used to demonstrate removal of the membrane. Inductively coupled plasma mass spectrometry (ICP-MS) indicated brown eggshells without membrane had a higher calcium carbonate content suggesting the purification technique worked well. Although composite tensile strengths and flexural strengths were lower than the pure bio-epoxy, the composites containing brown eggshells (with membrane) had slightly better strengths than composites containing purified brown eggshells (without membrane) and mineral limestone for the same particle size of 32 µm. The organic membrane contains proteins on the surface of the eggshells which may be beneficial for chemical bonding to occur with the bio-epoxy resin. Filler contents of 5–10 wt% were acceptable for tensile and flexural strengths. Scanning electron microscopy (SEM) provided visual observations of the fractured surfaces where an increase in surface roughness was related to an increase in filler loading, implying changes occurred within the composite materials. Brown eggshells can be exploited as a waste management opportunity for use as a filler in bio-epoxy composites.

Waste chicken feather biofiller reinforced bioepoxy resin based biocomposites — A waste to wealth experimental approach

Utilizing poultry wastes, particularly chicken feathers, in biopolymer composites is seen as an important aspect in lowering the environmental pollution and paving a new path to sustainability. The main objective of this experimental study is to develop polymer composites reinforced with waste chicken feather fillers and evaluate their physical, mechanical, and thermal characteristics. The composites were fabricated through an open mold casting process using bio epoxy (SR-33 Greenpoxy) as the matrix and chicken feather filler as a reinforcement in three distinct weight fractions (2.5, 5, and 7.5 wt%). To evaluate the effects of filler content on the mechanical properties of the fabricated bio-epoxy composites, they were subjected to tensile, flexural, impact, and hardness tests. The findings from the experimental studies demonstrated that the composites containing 2.5 wt% of chicken feather filler had improved mechanical properties, thermal stability, and crystallization behaviour. The thermal attributes of samples included a greater melting point, lower recrystallization temperature, higher glass transition temperature, and quicker crystallization rates. The Scanning Electron Microscope analysis of the fracture surface morphology of the biocomposites showed a better interfacial adhesion between the filler and matrix. It could be concluded from the results that the waste chicken feather can be used as potential filler reinforcements for begetting natural composites for various low- and medium-density structural and non-structural applications.

Static and Impact Properties of Flax-Reinforced Polymers Prepared with Conventional Epoxy and Sustainable Resins.

The study assessed the tensile, flexural, and impact properties of composite materials reinforced with flax fibers, employing three distinct resin types. The composite laminates were fabricated using three commercial resins: a conventional epoxy resin, an epoxy resin with a 31% weight concentration of bio-renewable content, and a recyclable methyl methacrylate infusion resin. This aims to assess if there exists a commercially available alternative to the traditional epoxy resin that can reduce the overall carbon footprint of composite materials. To investigate the influence of humidity on the mechanical behavior of the flax layers, a drying treatment was applied to the fibers before the infusion process. Micro-computed tomography analysis revealed that heat treatment resulted in a reduction of porosity, although it did not affect the mechanical response of the composite laminates. Moreover, laminates produced with non-recyclable and sustainable resins exhibited no significant change in tensile and flexural modulus. In contrast, those produced with recyclable resin demonstrated a slight reduction in the strengths of the composite laminates. Conversely, out-of-plane impact tests and repeated impact tests indicated that composites prepared with recyclable and bio-epoxy resin formulations present superior damage resistance to repeated impact compared to traditional epoxy resin.

Evaluation of Mechanical Performance and Antibacterial Efficacy of Alumina‐Silver Nanoparticle‐Reinforced Bioepoxy for Dentistry

The lack of mechanical and antibacterial characteristics of most dental resins impedes their broader applications in dentistry. Therefore, this study aimed to enhance biocompatibility and mechanical and antibacterial features of bioepoxy (BE) to be used in dentistry. The properties of BE were assessed prior to and after reinforcing with several loading of nanoalumina (Al2O3)/nanosilver (AgNPs) particles. The mechanical characteristics were evaluated using three‐point bending and Izod impact tests. The morphologies and surface roughness of pristine BE and nanoalumina/nanosilver‐reinforced BE composites were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The influence of these additives on the BE antibacterial properties were evaluated using the agar diffusion approach. The flexural strengths of the modified BE composites with nanoalumina/nanosilver particles were higher than those for additive‐free BE, and their values were considerably dependent on filler loading. The impact strength and flexural strength of composite materials were greater at hybrid reinforcement loading of 2 wt%. At such ratio, an increase of approximately 33.8% was obtained in the flexural strength compared with that of blank BE. On the other hand, the incorporation of higher proportions of nanoparticles led to a decrease in overall properties of composites, yet they were higher than that of additive‐free BE. The flexural strength for the composite containing 0.5 wt% AgNPs and 3.5 wt% Al2O3 was higher than the value stated for the nanoparticles‐free BE by 18.7%. Furthermore, the composite comprising 0.5 wt% of each of the nanoparticles had a great ability to alleviate the spreading of Staphylococcus aureus and Escherichia coli when compared with the resin and composites with other formula. For instance, the diameter of inhibition zone (DIZ) against Staphylococcus aureus of the aforementioned composite increased about 16% than that of additive‐free BE. All these features make this composite system a promising candidate in biomedical applications especially in dental related applications.

Eco-friendly Synthesis of Novel Phosphorus Flame Retardants for Multiple Purposes

The synthesis methods of most parts of phosphorus (P)-based flame retardants apply harmful and toxic reagents, and the formation of byproducts is often inevitable. The synthesis of P-based flame retardants (FRs) according to the green chemistry approach has been investigated. Two FRs have been prepared via an addition reaction of phosphorus-pentoxide and alcohols. These molecules can be used as additive FRs after salt formation or as precursors for flame retardant surface treatments of natural fibers. The flame retardant efficacy of the synthesized additives was assessed in a bioepoxy resin system through UL-94 and limiting oxygen index tests, while their mode of action was determined by the investigation of gas-phase degradation products and thermogravimetric analysis (TGA). The prepared adduct was also used in the formulation of a reactive flame-retardant surface treatment for cellulosic fibers. In TGA tests, the treated fibers produced significant amounts of char residue.

The green catalyst: Role of hemp fibers in the curing reaction of bio-based epoxy composites

Understanding the curing behavior of epoxy is a critical aspect in the production of epoxy-based composite and pivotal for process optimization. This study focusses on evaluating the curing kinetic parameters of hemp fiber/bio-epoxy composite at different fiber loading (0–30 wt%). The apparent activation energy was determined using Vyazovkin model. The results revealed an intricate chemistry between hemp fibers and bio-epoxy curing mechanism. The activation energy decreased upon the addition of fibers, indicating the catalytic effect of hemp fibers in the curing kinetics of epoxy resin. Further, at low fiber loading exhibiting augmented curing reaction up to 15 wt% fiber loading, whereas a decreased trend was observed thereafter. As a result, the curing time required to cure the bio epoxy was reduced notably when the fiber loading was less than 15 wt%. Hemp fibers with excellent functional groups such as hydroxyl moieties that actively facilitated the curing reaction, providing insight into their role of augmenting curing efficiency. This research provides crucial insights into tailoring the curing conditions and augment the process control efficiency in the manufacturing of thermoset composites.

Physical-Mechanical evaluation of a hybrid sisal fibre/banana stem fibre/bio epoxy biocomposite as a replacement alternative to conventional materials

This work develops a hybrid composite material using a bio-epoxy resin matrix reinforced with natural sisal and banana stem fibres. The vacuum-assisted resin infusion technique uses to define the appropriate proportions to guarantee the adhesion of the reinforcement. With the physical-mechanical characterisation of the density of 1041 Kg/mᶟ, a flexural resistance of 160.43 MPa, and Young's modulus of 2.17 GPa, the adhesion evaluated using SEM images (scanning electron microscopy) and shows separation between resin and reinforcement less than 10μm. With these properties, using the Granta Edu Pack tool, conventional materials such as polypropylene(PP), polyester, cellulose acetate, polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), cardboard and wood were found, with similar properties, and the hybrid biocomposite can replace that.

Physico‐mechanical, and thermal properties of sisal/hemp/Kevlar fibers, fly ash and Titanium Carbide nanoparticles reinforced bioepoxy composites

AbstractIn the present investigation, the chemically treated and untreated sisal/hemp fibers, fly ash or titanium carbide (TiC) nanofillers, and Kevlar fabrics reinforced bio epoxy (Sr 56) polymer matrix were manufactured using the wet layup method. Experimentation was performed to study the physical, mechanical and thermal properties. This investigation also includes determining the influence of accelerated weathering on the specimen surface for 5 months. The tensile fracture of the sample before and after the accelerated weathering from scanning electron microscope (SEM) pictures exhibited that the extensive failure principles in the laminates in terms of matrix cracking, fiber breakage, delamination, and fiber pull out. The thermal analysis examined the onset, endset temperature, transition loss, and carbon residue which were also reduced after the accelerated weathering. It exhibits that adding fly ash or TiC nanoparticles as an altered inhibitor against the weathering in the bio epoxy hybrid composite scheme can reduce the undesirable impacts from moisture and Ultra‐violet light exposure.Highlights Sisal/hemp fibers were chemically treated to reduce hydrophilicity. Contact angle of KSCHCTBE56 improved to 84.04°. SEM confirmed uniform dispersion of fillers and enhance mechanical strength. Mechanical and thermal characteristics reduced after accelerated weathering.

PROPERTIES OF BIOCOMPOSITES FROM WASTE EGGSHELL AS FILLERS

<p>In recent years there has been a heightened concentration on the industrial subsectors that are the primary contributors to environmental pollution. Filler materials made from mineral limestone, which is composed of calcium carbonate (CaCO3), are utilized in the production of polymer composites in order to lower production costs and improve the qualities of some of the composites. On the other hand, eggshells are typically regarded as waste despite the fact that they contain significant amounts of CaCO3 in addition to certain organic membranes. The purpose of this research is to investigate the use of thermal and chemical treatments to produce purified eggshell powder with the interest of utilizing waste eggshell as an alternative to limestone. Polymer composites were developed using bio-epoxy resin with various quantities of eggshell, refined eggshell, and limestone fillers (5%, 10%, and 20% weight). Eggshell could be utilized as filler in bio-epoxy composites, which could then be employed in applications that require a lower cost but a greater tensile and flexural modulus.</p>

Autonomous self-healing in green epoxy thermosets for flexible functional coatings

In this study, self-healing in a plant-based bioepoxy resin has been reported by incorporating reversible ionic groups in the networks of epoxy resin using a simple blending process with ionic liquid. The interaction between the hydroxyl groups in epoxy resin and ionic groups in ionic liquids was reversible. Such material with reversible reactive bonds was expected to show instantaneous self-healing of minor cracks. To study the self-healing efficacy of the system, tensile and nanoindentation tests were performed. The tensile measurements reported the retention of mechanical properties after the reassembling of ionic clusters due to self-healing. It was observed that the self-healed samples retained ca. 42 % and 53 % of their tensile strength and elongation at break. Furthermore, nanoindentation repairing studies were carried out by making a nanoindentation mark on the prepared samples and measuring the needed time to undertake autonomous self-healing. Interestingly, the self-healing was initiated immediately (<3 sec) after the nanoindentation, although with scarring. The complete self-healing of the damage was observed after 48 h. Thus, the modified samples showed improved self-healing under nanoindentation test conditions. Further, studies were conducted to understand the thermal, morphological, and physical properties of the prepared blend. All these studies prove that the prepared blend is a promising material in application areas such as flexible indoor coatings.

Optimization Analysis of Hardness Test for Powdered Pentaclethra macrophylla Pod /Bio-Epoxy Resin Based Brake Pad Composite Using Central Composite Design

This work examined the optimization of hardness test for Powdered Pentaclethra macrophylla Pod /Bio-Epoxy Resin Based Brake Pad Composite Using Central Composite Design. The Pentaclethra macrophylla pod was manually cleaned and sun-dried for about three hours per day for three days. The sun-dried Pentaclethra macrophylla pod was later ovum dried at a temperature of about 110oC for three hours to achieve a constant weight and subsequently allowed to cool to room temperature. The ovum-dried Pentaclethra macrophylla pod was crushed to powder form using locally fabricated grinding machine and sieved. Part of the sieved powdered pod was carbonized in a heat treatment furnace at a temperature of about 950oC. Pre-impregnated process was used to prepare the brake pad composite samples. The weights of the powdered Pentaclethra macrophylla pods and bio-epoxy resin were varied while those of the lubricant, abrasives, friction modifier, catalyst and accelerator were kept constant The weights of the reinforcement i.e. powdered Pentaclethra macrophylla pods were varied between 10 wt. % and 50 wt. % at an interval of 10 wt. %. The formulation was poured into a wooden mould 50 mm × 50 mm × 8 mm placed in a hot platen press at temperature of about 180oC, a moulding pressure of 15MPa and a curing time of 5 minutes. Post-heat treatment of the composites was performed in a hot air oven for a period of 4 hours at 180 °C. The produced brake pads were evaluated for hardness in accordance to ASTM D785 standard using Rockwell Scale K hardness testing machine. The results of the test showed that 150μm particle size reinforced brake pad sample had higher hardness values of 105.7 and 106.4 at 20wt. % and 30wt. % respectively. This result was also confirmed by the Central composite design (CCD) where maximum hardness values of 107.31 and 107.63 were obtained at 20wt. % and 30wt. % respectively.

Natural Fiber Composite with α-Resorcylic Acid Based Bio-Epoxy Matrix

Comprised of biopolymer matrix and/or bio-fiber reinforcement, bio-composites are environmentally friendly, lightweight, sustainable, and normally biodegradable. Their unique characteristics have enabled them an alternative material for replacing conventional metallic materials and other composites such as glass fiber reinforced composites. This work is focused on developing and characterizing a novel bio-composite that combines a natural fiber reinforcement with a unique α-resorcylic acid-based epoxy bio-resin. Kenaf fiber mats are impregnated with the epoxy bio-resin and compression molded into a bio-composite. Thermal properties of the bio-composite are characterized with differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). Indentation testing in a micro-scale is conducted on the bio-resin matrix and the fiber cross sections. The elastic modulus of the fiber transverse cross section is found to be 7.8 GPa, higher than that of the bio-epoxy resin, 4.3 GPa. Furthermore, the tension performance of the bio-composite is evaluated and compared with that of a conventional epoxy composite with similar kenaf fiber percentage. The bio-epoxy composite has comparable tensile modulus and strength with the conventional epoxy composite. Finally, the fracture surface of the tested samples is characterized using scanning electron microscopy (SEM) and different failure modes, such as fiber fracture, fiber pullout, fiber defibrillation, and matrix fracture, are observed. It is concluded that this novel bio-composite has a great potential to replace conventional epoxy resin based composite for semi-structural applications.

Towards green composites: Bioepoxy composites reinforced with bamboo/basalt/carbon fabrics

Recently, the awareness of global warming was stimulated in terms of material usage. Interestingly, the incorporation between fiber reinforcement and epoxy resin was applied in various applications which were entrancing in automotive, construction, and aerospace industrial as hybrid composite materials. The aim of this study is focused on the substitution of synthetic epoxy with bioepoxy resin and also the replacement of synthetic-based composites with fully biobased composites. To the best of our knowledge as of now, there is no work has been published on this concept. The synthetic epoxy and bioepoxy composites with bamboo (BB)/basalt (BS)/carbon (CB) hybrid composites with laminate stacking BSBBBS (basalt + bamboo + basalt) and CBBBCB (carbon + bamboo + carbon) hybrid composites were fabricated by the compression molding technique. The fabricated composites were subjected to the accelerated weathering test. The composites before and after the accelerating weathering test were tested and compared. The properties such as tensile, impact, morphology, thermal analysis, thermomechanical, contact angle, and water absorption tests were carried out. The hybrid composites showed excellent retention in mechanical properties even after the accelerated weathering test. The results showed that the bioepoxy/bamboo/basalt/carbon hybrid composites can be substituted with synthetic epoxy composites in automobile and structural applications in all weather conditions. • Use of green materials in the composite industry. • Incorporation of biofibers in bioepoxy resin to produce biomaterials. • Biocomposites for automobile and structural applications.