Natural Fillers Research Articles

In-depth analysis of the influence of bio-silica filler (Didymosphenia geminata frustules) on the properties of Mg matrix composites

A novel metal matrix composites (MMC) with Mg matrix reinforced with natural filler in the form of Didymosphenia geminata frustules (algae with distinctive siliceous shells) are presented in this work. Pulse plasma sintering (PPS) was used to manufacture Mg-based composites with 1, 5 and 10 vol.% ceramic filler. As a reference, pure Mg was sintered. The results show that the addition of 1 vol.% Didymosphenia geminata frustules to the Mg matrix increases its corrosion resistance by supporting passivation reactions, and do not affect the morphology of L929 fibroblasts. Addition of 5 vol.% the filler does not cause cytotoxic effects, but it supports microgalvanic reactions leading to the greater corrosion rate. Higher content than 5 vol.% the filler causes significant microgalvanic corrosion, as well as increases cytotoxicity due to the greater micro-galvanic effect of the composites containing 10 and 15 vol.% diatoms. The results of contact angle measurements show the hydrophilic character of the investigated materials, with slightly increase in numerical values with addition of amount of ceramic reinforcement. The addition of Didymosphenia geminata frustules causes changes in a thermo-elastic properties such as mean apparent value of coefficient of thermal expansion (CTE) and thermal conductivity (λ). The addition of siliceous reinforcement resulted in a linear decrease of CTE and reduction in thermal conductivity over the entire temperature range. With the increasing addition of Didymosphenia geminata frustules, an increase in strength with a decrease in compressive strain is observed. In all composites an increase in microhardness was attained.The results clearly indicate that filler in the form of Didymosphenia geminata frustules may significantly change the most important properties of pure Mg, indicating its wide potential in the application of Mg-based composites with a special focus on biomedical use.

Potential contribution of steel slag fillers to asphalt mastic in terms of microwave heating efficiency, electromagnetic mechanisms and fatigue durability

ABSTRACT This paper investigates the potential contribution mechanisms of steel slag fillers in asphalt mastic, covering asphalt-filler interaction mechanisms, microwave heating efficiency, electromagnetic absorption mechanisms, and fatigue durability. The physico-chemical microscopic mechanisms of the steel slag filler, the limestone filler and the interactions between the fillers and the styrene-butadiene-styrene (SBS)-modified binders were characterized. The microwave-heating efficiency of steel slag-based asphalt mastic (SBS-SS) and limestone-based asphalt mastic (SBS-LS) was quantified. The dielectric behaviour of the fillers and the corresponding mastic was further characterized to reveal the electromagnetic mechanisms associated with the microwave heating technology. The stiffness evolution and the fatigue durability of SBS-based bitumen under the effectiveness of steel slag and limestone fillers were assessed by the viscoelastic continuum damage theory model and dissipative energy approaches. The steel slag fillers exhibited a greater potential to promote microwave heat efficiency than the natural stone fillers due to higher ferric oxide compositions. SBS-SS mastics have an overall greater dielectric constant and loss factor than those of SBS-LS mastics, resulting in superior electric field energy storage and conversion capabilities. The addition of steel slag fillers magnifies the load sensitivity of the bitumen and weakens the fatigue impedance and fatigue life of asphalt mastic composites.

Green synthesis of chitin/lignin based-polyurethane composites

Polyurethanes (PU) are still among the most promising high-performance materials in industrial applications. Nevertheless, the development of sustainable and efficient materials is an ongoing challenge for the plastics industry. In recent years there has been growing interest in utilizing natural materials such as chitin and lignin as additives in polyurethane foam production. This study focuses on the utilization of sustainable chitin–lignin filler for polyurethanes with the aim of producing sustainable, cost-effective, and efficient foam materials. A chitin–lignin filler was prepared using a mechanochemical approach, and flexible polyurethane foams (FPUFs) were synthesized with varying amounts of chitin–lignin additive. The resulting foams were characterized using various analytical techniques, including scanning electron microscopy, compression testing, tensile strength analysis, and measurements of surface free energy and contact angle. Possible interactions between the filler and PU were analyzed by means of FTIR spectroscopy. The results show that the addition of chitin–lignin filler improved the mechanical properties (in comparison to pristine chitin and lignin as filler), with a significant reduction in the compression set of the polyurethane foams, a crucial property in the production of seat foams. Synergy was observed between chitin–lignin filler in PU foam. Overall, the study demonstrates the potential of chitin–lignin as a sustainable and efficient natural filler that can be effectively applied on the industrial scale. The combination of these two biopolymers led to a polyurethane composite with better mechanical properties. Additionally, the use of biopolymers (chitin and lignin) as a filler for FPUFs is one of the options for the management of waste materials, which is in line with the idea of sustainable production.

Tribological and mechanical properties investigations on polymer based composites reinforced with bio fillers

Bio-composites are currently considered a viable alternative to conventional, nonbiodegradable polymers. Further increasing, the use of natural fillers helps keep the price of bio-composites down. Polylactic acid (PLA) served as the matrix in this study, and Rice Husk Fibre (RH) and Walnut Shell Fibre (WS) were used as filler materials. Rice Husk Ash (RHA) at 0%, 2%, 4%, 8%, and 10% and Walnut Ash (WNA) at 2% are combined in the PLA matrix. The aim of this analysis was to investigate the impact of varying quantities of a silane-alkali processed rice husk fibre and walnut shell fibre (hybrid fibre) in a PLA-based composite with respect to mechanical, thermal, and tribological properties. Tensile, flexural, impact toughness then Shore D Hardness of approximately 192 MPa, 224 MPa, 6.91 J and 96 were achieved in composites containing alkali-silane-treated rice husk fibre at 10 wt% and walnut shell fibre at 2 wt%, correspondingly. The addition of 2 wt% WS fibre particle reduces the bio-specific composite's specific wear rate (SWR) to around 0.009 mm3/Nm and its coefficient of friction (COF) to about 0.42, respectively. In addition, by including particles made from 6 wt% Rice husk fibre and 2 wt% walnut shell fibre, the composites show promising thermal capabilities, with a Tg of 103◦C. These PLA bio-composites prove the use in aerospace, defence, sports, domestic infrastructure, automobiles, and industrial applications due to their improved mechanical, thermal, and wear characteristics.

Utilization of Festuca arundinacea Schreb. Biomass with Different Salt Contents for Bioethanol and Biocomposite Production

Soil salinity is one of the particularly important environmental factors, which limits the growth and development of plants, reduces the amount of crops and causes serious economic damage. The study found that Festuca arundinacea can be successfully used for the management and bioremediation of saline habitats, and it is characterized by a very well-developed root system and an average high biomass production of approx. 14.8 Mg∙ha−1, which can be used for industrial applications. Tall fescue biomass from soils with different levels of salinity was used to obtain bioethanol using 1.5% NaOH pretreatment and for the process of simultaneous enzymatic hydrolysis and ethanol fermentation (SSF). It was found that the content of Na+ ions in the tall fescue biomass had no significant effect on the amount of ethanol obtained (the average 19.32 g∙100 g−1 of raw material). F. arundinacea biomass was also used as a natural filler to obtain green composites using a biodegradable polylactide (PLA) matrix. It has been shown that tall fescue biomass with the lowest sodium content in biomass (approx. 2.5 mg∙g−1) from an area with high saline (above 6 g NaCl∙L−1) has the smallest effect on reducing the tensile and flexural strength of composites. Moreover, the highest value of bioethanol concentration (21.2 g∙100 g−1 of raw material) for this biomass sample was obtained.

The study of the feasibility and manufacture of slurry seal surface treatment with steel slag industry wastes: use of basic oxygen furnace (BOF) slag filler as raw material replacement

Slurry seal is a preventive maintenance method to preserve pavement. This research is focused on the effect of steel slag filler (SSF) as a natural filler (NF) substitute on the behaviour of slurry seal mixtures. Five different combinations containing 100% NF, 25% SSF + 75% NF, 50% SSF + 50% NF, 75% SSF + 25% NF, and 100% SSF based on the total filler weight were used. The samples were evaluated by the wet cohesion, wet track abrasion, loaded wheel-displacement, and loaded wheel-sand adhesion tests. For investigating the SSF impact on the performance characteristics of mixtures, an analysis of variance (ANOVA) was performed. The results indicated that mixtures with 75% SSF increase the bitumen cohesion by 45%, decrease the displacement by 50.8%, improve the abrasion resistance by 48.3%, and reduce the bleeding by 29.3%. ANOVA results showed that SSF has the greatest effect on increasing the adhesion and reducing the displacement in slurry seal.

COMPARATIVE STUDY OF THE EFFECT OF POLY(LACTIC- ACID), STARCH, CHARCOAL ON PHYSICO-MECHANICAL PROPERTIES OF VIRGIN AND WASTE LOW DENSITY POLYETHYLENE COMPOSITES.

A study was carried out to evaluate the effect of natural fillers on the mechanical properties of virgin and waste low density polyethylene. Samples of disposable sachet bags were obtained and blended with varying percentages of polylactic acid, starch, charcoal and maleic anhydride (M.A) in a 2 roll-mill mixer and compression molded to form composites using the two-roll mix and the compression molding machine for compounding. Samples were molded and cut according to ASTM for tensile strength, flexural strength, hardness and impact strength. From the results obtained, incorporation of the natural fillers reduced the tensile strength for the virgin composites more than the waste composites, similar results were observed with the flexural strength, hardness compared to the control sample. However, impact strength improved with increase with natural fillers.

THE STUDY OF USING NATURAL FILLERS ON THE BIODEGRADATION PROPERTIES OF VIRGIN/WASTE LOW DENSITY POLYETHYLENE AND VIRGIN/WASTE HIGH DENSITY POLYETHYLENE COMPOSITES.

A study was carried out to check the effect of natural filler on the degradation properties of virgin and waste LDPE and virgin and waste HDPE. Samples were collected and compounded with Maleic Anhydride as a compatibilizer between the polymer matrix and PLA, starch and charcoal. Using the two-roll mix and the compression moulding machine for compounding, samples were moulded and cut according to specifications for the test. Tests carried out were done according to ASTM for water absorption, soil burial and QUV. Results showed as the amount of natural filler increased, it improved water absorption up to 42 days for both virgin LDPE and HDPE, while it took 180 days for samples with more percentage of natural fillers to record mass loss due to degradation. The SEM result confirmed a lot of cracks and holes as a result of immiscibility from the poly blends and which aided with high water absorption and degradation. The QUV results also showed degradation of all samples after exposure time in the accelerated weathering test.

Numerical and Experimental Analysis of Mechanical Properties in Hybrid Epoxy-Basalt Composites Partially Reinforced with Cellulosic Fillers.

The current work is focused on numerical and experimental studies of woven fabric composites modified by hybridisation with biological (cellulosic) filler materials. The mechanical performance of the composites is characterized under tensile, bending and impact loads and the effect of hybridisation is observed with respect to pure and nonhybrid composites. Numerical models are developed using computational tools to predict mechanical performance under tensile loading. The computational prediction results are compared and validated with relevant experimental results. This research is aimed at understanding the mechanical performance of basalt-epoxy composites partially reinforced with micro-/nano-sized bio-fillers from cellulose and intended for various application areas. Different weave structures, e.g., plain, twill, matt, etc., were investigated with respect to the mechanical properties of the hybrid composites. The effects of hybridizing with cellulose particles and different weave patterns of the basalt fabric are studied. In general, the use of high-strength fibres such as basalt along with cellulosic fillers representing up to 3% of the total weight improves the mechanical performance of the hybrid structures. The thermomechanical performance of the hybrid composites improved significantly by using basalt fabric as well as by addition of 3% weight of cellulosic fillers. Results reveal the advantages of hybridisation and the inclusion of natural cellulosic fillers in the hybrid composite structures. The material developed is suitable for high-end applications in components for construction that demand advanced mechanical and thermomechanical performance. Furthermore, the inclusion of biodegradable fillers fulfills the objectives of sustainable and ecological construction materials.

Enhancing dry mix mortar strength with natural fillers and polymers

Dry mix mortars are becoming more and more popular in the world’s building materials market. Therefore, the issue of increasing the technological and mechanical properties of stucco mixes is relevant. The aim of the paper is modification of lightweight dry stucco mixes with fine limestone and perlite as well as with hydroxyethyl methyl cellulose and dispersible polymer. In order to investigate the different mixes, an 18-point experiment was designed. Density, compressive strengths and crack resistance of dry plaster mixes were studied using requirements of standard. Mathematical models were obtained for the compositions as a result of processing the experimental data. The regularities of the fillers’ and additives’ influence on the properties of the mixes were established, depending on their amount and combination. It was observed that methyl hydroxyethyl cellulose improves the crack resistance and compression strength, and contributes to a slight decrease in density. The crack resistance of plaster mortars changes more than 1.5 times, the most crack-resistant compositions have an average amount of porous fillers.

The development of composite reinforced hybrid fiber musa acuminata stem-hibiscus tiliaceust bark with filler liquid rubber as vehicle bumper

The characterized of the polyester composites reinforced of the hybrid fiber musa acuminata stem fiber (MASF)-hibiscus tiliaceust bark fiber (HTBF) with liquid rubber filler was studied. The object of research is the polyester composite material, hybrid natural fiber reinforcement and filler Carboxyl Terminated Butadiene Acrylonitryle (CTBN). The polyester composite material which is used as a vehicle bumper, is easily broken and has low heat resistance so that its shape easily changes/shrinks due to heat. This research aims to develop the tensile strength, impact toughness and heat resistance of polyester composites. The reason for using the MASF-HTBF hybrid fiber as a reinforcement for polyester composite materials is because MASF and HTBF are natural fibers that have great potential to be developed to improve the mechanical properties of polyester composites, as substitutes for synthetic fibers. In this study, the conditions of MASF and HTBF were given alkaline treatment by immersing them in 5 % NaOH solution for 24 hours then drying. The combined/hybrid ratio between the MASF and CTBF volume fractions is: 5 %:25 %, 10 %:20 % and 15 %:15 %. To increase impact toughness, CTBN filler is added with variations of 5 %, 10 %. The mechanical characteristics of the specimens were carried out by means of a tensile test and an impact test. The change in mass or shrinkage as a result is tested by TGA. The results showed that the MASF-HTBF hybrid fiber-reinforced polyester composite material with CTBN filler has better mechanical properties than single natural fibers, so it is important to develop it further as a material for making vehicle bumper

English

Starch fillers were extracted from three plant sources namely amora tuber, Tacca lentopeteloides; sweet potato, Ipomoea batatas; yam starch, Dioscorea rotundata and their particle size, pH, amylose, and amylopectin percentage decomposition determined accordingly. The starch was introduced into natural rubber in liquid phase (through gelatinization) by the latex compounding method and compounded according to standard method. The prepared starch/natural rubber composites was characterized by Instron Universal testing machine (UTM) for tensile mechanical properties. The composites was further characterized by x-ray diffraction and crosslink density analysis. The particle size determination showed that amora starch granules has the smallest particle size (156 × 47 μm) followed by yam starch (155 × 40 μm) and then sweet potato starch (153 × 46 μm) with the biggest particle size. The pH test also revealed that amora starch has a near neutral pH of 6.9, yam 6.8, and sweet potato 5.2 respectively. Amylose and amylopectin determination showed that yam starch has a higher percentage of amylose (29.68), followed by potato (22.34) and then amora starch with the lowest value (14.86) respectively. The tensile mechanical properties testing revealed that yam starch produced the best tensile mechanical properties followed by amora starch and then sweet potato starch. The structure, crystallinity/amorphous nature of the product composite was confirmed by x-ray diffraction, while the nature of crosslinking was confirmed by swelling test in toluene solvent using the Flory-Rehner approach. The increasing values of crosslink density in the starch/rubber composite is a clear evidence of good interfacial adhesion between the starch fillers and the rubber, hence good dispersion of starch fillers in the rubber. This research has rendered a workable strategy for enhancing interfacial interaction between a hydrophilic filler (Starch) and hydrophobic polymeric matrix (natural rubber) yielding moderately good tensile mechanical properties with prospects for the rubber processing industry. The studied fillers can partially replace carbon black as natural rubber fillers with reduced cost, no risk to human health and also an environment friendly approach. Key words: Natural rubber, fillers, starch, amylose, amylopectin, crosslink density, mechanical properties.

The influence of cassava starch on the properties of PLA/PBS/SCG films for packaging applications

ABSTRACT Fresh fruits and vegetables are perishable products with active metabolism during the post-harvest period; the proper packaging can extend shelf life. The objective of this research has been interested to produce bio-composite film packaging for fresh fruits and vegetables based on poly (lactic acid); PLA, poly butylene succinate; PBS, and natural filler (modified spent coffee grounds; SCG, and cassava starch; ST) by using blow film extruder. The bio-composite film varied in the weight percentage of ST at 0, 5, and 10%wt. control content of PBS at 5%wt. and SCG at 5%wt. The mechanical properties of the PLA blending with PBS can improve % Elongation of the biocomposite film. The cassava starch acts as a nucleating agent present in the cold crystallization temperature was decreased and the degree of crystallinity increased, as well as induced chain mobility, presented in a slight decrease of the glass transition temperature. The SCG and ST particles have a good distribution in the biopolymer phase, the film color was present in light-brown color because of the brown color of SCG particle. The addition of natural filler can improve the UV-light barrier properties, reduce costs, and increase the degradability rate of the film. The WVTR of the biocomposite film was increased with the amount of natural filler added. However, all the biocomposite films presented a water contact angle around 72–75°, this result is essential for the film to apply in a higher humidity environment. The food simulants with aqueous at 40°C and 4°C, 10% ethanol and 3% acetic acid for 10 days were present, the overall migration was less than 10 mg/dm2. The final product from biocomposite film can evaluate the food safety, UV-protection and prolong the shelf-life of fresh vegetables.

Development of hybrid composite with natural fillers for mechanical property and machinability study

The urge to build a more environmentally friendly future has motivated researchers to examine composites outside of synthetic fiber and continue to consider natural fibre polymer composite. This present research, the hybrid bio composite was developed by bio fillers and natural fibres. The preliminary investigation was done to examine the possibility of using natural fillers (palm and coconut shell) in natural fibre (hemp and basalt) reinforced polymer (NFRP) composite for manufacturing application. In that way initially mechanical (tensile and flexural) properties testing were done on four different combinations of NFRP by using palm and coconut shell particles, to their influence on mechanical properties (tensile stress 278 MPa and flexural stress 330 MPa). It was found that 5% wt. palm + coco shell fillers combination hybrid composite presented good results in mechanical properties. Then 5% wt. palm + coco fillers was added in the matrix phase of NFRP composite was developed and study the machinability properties by using Abrasive Water Jet Machining (AWJM). NFRP machining in the relationships of material removal rate (MRR), kerf angle and surface roughness has been experimentally examined for various process parameters (nozzle pressure, distance stand and transverse speed). The research values for quality properties (MRR, Kt and Ra) were analysis-based on the trimming factors by developing the Taguchi method. The influence of optimized input process parameters on quality features were examined by utilizing experiential models. From this study, it is noticeable that, filler material in natural fiber composites reduces the kerf angle and the low and very high traverse speed leads the wide disparity in kerf inclination. For obtaining the good surface roughness and material removal rate medium traverse speed and medium stand of distance is the significant parameter respectively and moreover impact of jet pressure on surface finish is 3 times lower than the impact supplied to the surface finish by traverse speed

Influence of printing-based factors on the mechanical properties of hexagonal lattice-structured 3D printed novel walnut shell/polylactic acid composite

The incorporation of bio-based natural fillers and lattice structures in thermoplastic polymer has superior advantages such as a reduction in the usage of conventional polymers with improved damping and mechanical properties. The present work focuses on the development of Walnut Shell/PLA (WSP) lattice-structured composite by the Fused Filament Fabrication technique. The flexural strength, compression strength, and thickness error properties of the hexagon lattice-structured WSP composites are optimized by varying Printing-Based Factors (PBFs) which include infill density (60%, 80%, and 100%), nozzle temperature (190°C, 210°C, and 230°C), printing speed (10 mm/sec, 20 mm/sec, and 30 mm/sec), and layer height (0.1 mm, .2 mm, and .3 mm). The flexural and compression test experiments were conducted as per the ASTM D790 and ASTM D695 standards. The process optimization of the measured responses is made by using Taguchi grey relational grade optimization technique. The experimental outcomes such as compressive and flexural strength and minimal dimensional error are converted into the Grey Relational Grade (GRG) for the optimization process. The results show that the Signal-to-Noise ratio (S/N) from the measured GRG clearly shows that, the lower layer height of 0.1 mm, higher nozzle temperature of 230°C, higher infill density of 100%, and average printing speed of 20 mm/sec is an optimal experimental condition for attaining higher strengths and lower errors. From the Analysis of Variance (ANOVA) analysis, the printing temperature, and layer height are the most persuasive PBFs for the mechanical and physical characteristics with respect to the incorporated lattice structure. The optimized experimental conditions develop maximum flexural and compressive strengths of 4.98 MPa and 28.19 MPa, in addition to a lower thickness error of .186 mm obtained for hexagon lattice-structured WSP biopolymeric composites.

Effect of natural fillers as reinforcements on mechanical and thermal properties of HDPE composites

Demand for natural fibers has increased in recent years due to the requirement for biodegradable materials. Owing to the increasing awareness on the overuse and over-dumping of plastics in the environment, the current work focused on a solution by using tree leaves as a particulate reinforcement which is one of the common waste products of trees. In this regard, Norfolk pine (NOP) tree leaf particulates filled High-Density Polyethylene (HDPE) composites were fabricated through injection moulding technique with different filler weight % of 0, 10, 20, 30, 40, and 50 wt. %. The study of the crystalline structure of the fillers and the detection of functional compounds in the materials were carried out through X-ray diffraction (XRD) and Energy dispersive X-ray spectroscopic (EDX) analysis. Tensile strength, compressive strength, and flexural strength of the fabricated composite specimens were also assessed. Results revealed that the mechanical properties of the 30 wt. % pine tree leaf-filled HDPE composites were found to be superior when compared to pure HDPE composites. The failure surface morphology of the composite samples was examined using scanning electron microscopy (SEM). The melting point and decomposition of 30 wt. % NOP leaf particulate-filled HDPE composites specimen, whose mechanical properties were higher, were examined using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). From the results, it was found that NOP fillers can be used as an effective reinforcement in polymer composites.

Color Stability Enhancement of Curcumin Bioplastic Films Using Natural Hybrid Fillers of Montmorillonite and Revalorized Cellulose

Naturally colored packaging systems with improved color stability are essential as alternatives to mainstay synthetic colored conventional plastics, which typically present high toxicity and environmental pollution challenges. Herein, we report a versatile all green fabrication process for colored bioplastic films. Curcumin (CUR), a model plant-based colorant, was incorporated with newly developed natural hybrid fillers of montmorillonite (MMT) and biomass waste-recovered cellulose (CEL) for improved color stability performance. The CUR-based hybrid fillers were compounded with polylactic acid (PLA) to fabricate sustainable, colored composite films via hot-melt extrusion. Fourier transform infrared (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) results indicated good compatibility between the filler counterparts. Macro- and microstructure analysis of the colored films confirmed the good dispersion of the natural hybrid fillers within the PLA matrix. No change was observed in the thermal properties of the colored films, while dynamic mechanical analysis (DMA) results demonstrated a moderate increase in the films’ elastic modulus, from 870 to 970 MPa. The color entrapment efficiency of the hybrid filler-based films was evaluated through a study of CUR release in ethanol. A sustained CUR release profile reaching around 50% after 48 h was observed in the hybrid filler-based films in contrast to 80% in the PLA–CUR film. This was correlated with the significantly improved color stability of the PLA films containing the hybrid fillers under weathering conditions of UV irradiation, high temperature, and humidity. Over a period of 10 days, the CUR-CEL-MMT-based films had relatively consistent color stability, showing a color shift value (ΔE*) of only 1.1 in comparison to 5.1 for the PLA film containing only CUR.

Influence of Vinyl Acetate Content and Melt Flow Index of Ethylene-Vinyl Acetate Copolymer on Physico-Mechanical and Physico-Chemical Properties of Highly Filled Biocomposites.

Highly filled biocomposites may be used as biodegradable masterbatches that manufacturers add to traditional polymers for making plastic goods more biodegradable. Biocomposites based on various trademarks of ethylene-vinyl acetate copolymer (EVA) and natural vegetable fillers (wood flour and microcrystalline cellulose) were studied. The EVA trademarks differed both in terms of the melt flow index and in the content of vinyl acetate groups. The composites were created as superconcentrates (or masterbatches) for the production of biodegradable materials based on vegetable fillers with polyolefin matrices. The filler content in biocomposites was 50, 60, 70 wt.%. The influence of the content of vinyl acetate in the copolymer and its melt flow index on the physico-mechanical and rheological properties of highly filled biocomposites was evaluated. As a result, one EVA trademark with high molecular weight that has a high content of VA was chosen because of its optimal parameters for creating highly filled composites with natural fillers.

A close look for the γ-ray attenuation capacity and equivalent dose rate form composites based epoxy resin: An experimental study

The present work aims to develop new epoxy-based composites with halloysite, basalt, PbO, CuO, and Bi2O3 fillers. The role of the utilized fillers in the structural properties of the fabricated composites was studied using the Fourier transform infrared spectrometer and scanning electron microscope. Additionally, the role of utilized fillers in reducing the equivalent dose rates from Co-60 and Cs-137 isotopes were experimentally examined where the equivalent dose rate values ranged between 1.95 μSv/h–1.36 μSv/h (for E@PbO), 1.88 μSv/h–1.31 μSv/h (for E@Bi2O3 composite), 1.97 μSv/h–1.43 μSv/h (for E@CuO composite), 1.96 μSv/h–1.46 μSv/h (for E@Halloysite composite), and between 1.94 μSv/h–1.47 μSv/h (for E@ Basalt composite), raising the composites’ thickness between 1.0 and 4.65 cm, at gamma-ray energy of 0.662 MeV. Based on the examined equivalent dose rate, the shielding parameters of the fabricated composites were evaluated where the radiation protection efficiency f reaches 36.4%, 33.2%, 31.8%, 38.8%, and 31.3% for epoxy resin reinforced by 25 wt% of PbO, CuO, halloysite, Bi2O3, and basalt, respectively, at gamma-ray energy of 0.662 MeV. The observed outcomes demonstrated that the radiation shielding parameters of low-cost epoxy resin with natural fillers (halloysite and basalt) are marginally inferior to those of CuO, PbO, and Bi2O3 fillers. These results support the feasibility of creating shielding polymer composites using natural fillers rather than expensive and hazardous heavy-weight fillers.

Simulation of Water Absorption of Epoxy Reinforced Composite Using Polynomial Model on MATLAB Environment

Application of MATLAB software for water absorption test, which entails the rate by which a material diffuses and retain water molecule, on epoxy reinforced with coconut shell fiber (CSF), aluminum oxide (Al2O3), and silicon carbide (SiC) composites have been investigated. Five specimens (E, S1, S2, S3 and S4) were developed using compression molding on different percentage of fibers. The water absorption test was conducted using suitable American Society for Testing and Material (ASTM) which involves different water solutions. It was observed that sample ‘E’ shows maximum water absorption maybe due to absence of reinforced fibers. Specimen S1 indicated less water absorption, maybe due to presence of natural filler. Sample S4 shows trend on least water absorption, maybe due presence of higher percentage of natural synthetic fibers. Validation of the experiments using 2020 Commercial License Model MATLAB software, which were compared with the experimental result using the root mean square error (RMSE) statistical parameter and graph of point of intercept. The predicted data developed through the MATLAB software, established 95% confidence bounds on RMSE, which indicated 0.012 range of standard deviation between the experimental and simulation results, which avoids the under fitting and over fitting problem, also, when compared using a graph of point intercept, followed the same trend of result from the experiment.