Natural Composite Materials Research Articles

Preparation of enzymolysis porous corn starch composite microcapsules embedding organic sunscreen agents and its UV protection performance and stability

In this paper, a natural composite wall material sunscreen microcapsule was prepared, which significantly improved the SPF value and photostability of the embedded sunscreen agents. Using modified porous corn starch and whey protein as wall materials, the sunscreen agents 2-[4-(diethylamino)-2-hydroxybenzoyl] benzoic acid hexyl ester and ethylhexyl methoxycinnamate were embedded by adsorption, emulsion, encapsulation and solidification. The embedding rate of the obtained sunscreen microcapsules was 32.71 % and the average size was 7.98 μm; the enzymatic hydrolyzed starch formed a porous structure, its X-ray diffraction pattern did not change significantly, and the specific volume and oil absorption rate increased by 39.89 % and 68.32 %, respectively, compared with those before enzymatic hydrolyzed; The porous surface of the starch after embedding the sunscreen was covered and sealed with whey protein. 120 h sunscreen penetration rate was lower than 12.48 %; Compared with the lotion containing the same amount of sunscreen but not encapsulated, the SPF value of the lotion containing sunscreen microcapsules increased by 62.24 %, and the photostability of sunscreen microcapsules increased by 66.28 % within 8 h under the irradiation intensity of 25 w/m2. The wall material and the preparation method are natural and environmentally friendly, and have a good application prospect in low-leakage drug delivery system.

Effect of reinforcement of Alkaline-treated sugar palm/bamboo/kenaf and fibreglass/ Kevlar with polyester hybrid biocomposites: mechanical, morphological, and water absorption properties

In this age of globalisation, decreasing synthetic resources have exhilarated global communities to apply natural fibres as substitute materials for green technology development. The growth of products from lignocellulose fibre-reinforced composites has been a wide topic among material scientists and engineers due to their abundance, sustainability in nature, biodegradability, and availability at low cost. A series of natural/synthetic hybrid fibre-reinforced composites are prepared by reinforcing polyester resin as the matrix. Natural fibres such as sugar palm/kenaf/bamboo with fibreglass/Kevlar hybrid composite materials were used in this research to determine the mechanical and water absorption properties. The difference between the weight content of natural fibres which were 0 (control sample), 15, 45, and 60 wt% influenced their strength of mechanical properties. The Charpy impact and tensile test were performed following the ASTM D6110-10 and ASTM D3039, respectively. A water absorption test in accordance with ASTM D570-98 was also performed on three different natural fibre-reinforced hybrid composite materials to determine which composite had the best water resistance property. The results showed that hybrid fibre-reinforced composite for 45 wt% kenaf fibre possessed better tensile properties and 60 wt % sugar palm fibre performed better during the Charpy impact strength test compared to other natural/synthetic hybrid fibre-reinforced composites. It was concluded that sugar palm fibres demonstrated the best water resistance in this study.

On concurrent multiscale topology optimization for porous structures under hygro‐thermo‐elastic multiphysics with considering evaporation

AbstractLightweight polymeric and natural composite materials are extensively used in modern structures, especially with the demands for environmentally friendly products as well as lowering energy consumption. Furthermore, a high performance‐to‐weight ratio can be attained by utilizing porous composites. However, hygral and thermally induced loads are limiting the robustness of polymeric and natural composite materials, therefore; in this research, concurrent multiscale multiphysics topology optimization is used to design lightweight porous composite structures that have resilience toward mechanical as well as hygral and thermal loads. By establishing two independent representations of the design problem, that is, macro and microscale domains, a concurrent topology optimization framework is implemented, and the effective properties of the microscale (i.e., elastic, thermal conductivity, moisture diffusivity tensors, and hygral as well as thermal expansion coefficients) are calculated and used as the hygro‐thermo‐elastic properties of the macroscale using in‐house MATLAB codes. For hygral physics, moisture transport, as well as evaporation, are simultaneously considered in this study. A sensitivity analysis was conducted on the multiphysics concurrent optimization scheme in order to account for the coupling of macro and microstructure, as well as hygro‐thermo‐elastic physics. Multiple numerical cases were examined, which included different loading and boundary conditions, as well as various spatial configurations. The results showed attaining a high stiffness‐to‐weight ratio for the multiscale optimized porous structure compared to the single‐scale solid structure. Furthermore, a study was conducted on multiple microstructure subsystems to examine the impact of microstructure systems on macrostructure dependence. By combining several microstructures into a single macro design domain, design flexibility was enhanced and the performance‐to‐weight ratio was improved. The study was expanded to include the evaluation of hygro‐thermo‐elastic multiscale multiphysics with an evaporation problem, which was demonstrated through several numerical examples. The introduced formulations showed a successful application of the concurrent multiscale optimization formulations and good coupling on the macro and microscale. Also, the formulations demonstrated a strong influence between the macro and the microscale of the design problem for the topology optimization methods. The successful application of the concurrent multiscale optimization method in this research highlights its potential for designing more efficient and effective structures in the future.

Effect of Surface Modification on the Impact Strength and Hardness of Areca Husk Fibre Reinforced Polyester Resin Composite

Reinforced natural fibre composite materials are attracting greater attention in the area of material engineering due to their low density, low cost and higher mechanical strength. In the present study, the Areca Husk Fiber (AHF) was extracted through the retting process. The surface modification of AHF was done by chemical treatments such as mercerization, potassium permanganate treatment, benzoylation, acrylation and acetylation. The surface modification was studied through FE-SEM imaging. The composites of surface modified AHF reinforced polyester resin composites were prepared as per ASTM standards using polyester resin as matrix material and methyl ethyl ketone peroxide (MEKPO) as hardener. The Izod-Charpy impact strength, Hardness (Shore-) hardness analysis was carried out to study the mechanical behaviour of the composites. The results showed that surface modification of AHF can enhance the impact strength of the composite materials but not the hardness of the composites.

Exploration of mechanical properties of hemp fiber/flax fiber reinforced composites based on biopolymer and epoxy resin

Recently natural fiber-reinforced polymer composite materials are highly growing both in the relationship of their manufacturing industries applications such as automobile, lightweight biosensor chips, and microfluid and fundamental research as they are renewable, low, eco-friendly, biodegradable and completely recyclable. The hemp and flax solutions have not only met the technical requirements of prepared composite but also reduced environmental impacts. The present study involves the investigation on mechanical behavior such as flexural strength, flexural modulus along with moisture absorption performance of flax and hemp fiber composite is reinforced with the natural resin and epoxy resin. The biodegradable composite by the help of synthesis of natural acids such as citric acid (CA) and maleic anhydride (MA). In additional acrylic acid (AA) and glycerol (GL) were used for synthesis of natural resin to be more reactive by condensation method. The laminate has been prepared by flax and hemp fiber reinforced with the epoxy resin. The prepared laminate has been used study the flexural and tensile studies by ASTM standard procedure. The mechanical properties of flexural test and tensile test has been studied by hemp fiber/flax fiber reinforced composites. The obtain results were compared with the natural fiber reinforced by natural resin and epoxy resin. Hence, this kind of light weight biocomposite materials has been utilized for many industrial applications.

Experimental analysis of natural composite material for helical gear

Before any conclusions can be reached regarding the qualities of natural composites, extensive research must be conducted and the resulting data analysed. Only after these two steps have been completed can any of the other actions be taken. An experimental inquiry is the primary topic of this study, with the objective of identifying the hardness, wear resistance, and impact strength of the natural composite that served as the primary focus of the examination. These features are utilised to establish the connection between the combination of natural composite with the material currently used for helical gears and the application of composites to helical gears. These qualities are used to determine the relationship between the mixture of natural composite and the material that is currently being used for helical gears. These qualities are used to determine the relationship between the mixture of natural composite and the material that is currently being used for helical gears. Specifically, the link is formed in order for the natural composite to replace the current material. These qualities are used to determine the relationship between the mixture of natural composite and the material that is currently being used for helical gears. Specifically, the link is formed in order for the natural composite to replace the current material. Specifically, the relationship is constructed in such a way that the natural composite can serve as an acceptable replacement for the current material. The mechanical properties of a substance are one method for evaluating the efficacy of a technique. This is one of the potential strategies. To build helical gear from composite material, the mechanical properties of the material must be enhanced. This will permit the gear to be manufactured. This is due to the composition of the used material.

A solution to improve the thermal efficiency of the exterior shell of a building using natural non-woven composite materials

امروزه، ارتباط علم بیومیمیکری با رشته‌های مختلف ازجمله معماری گسترش‌یافته است. بررسی الگوها، سامانه‌ها و عناصر زیستی، راهکاری جهت ایجاد راه‌حل‌ برای رفع مشکلات زندگی انسان­هاست. پیله کرم ابریشم ساختاری زیستی دارد و کامپوزیتی طبیعی است که در طول زمان تکامل‌یافته و پاسخگوی مناسبی در برابر شرایط زیست‌محیطی برای کرم ابریشم است، خواص فیزیکی و مکانیکی بالایی در برابر تنش‌ها و عملکردی مناسب به‌عنوان عایق در برابر شرایط دمایی محیط دارد. درک روابط ساختار پیله­ی کرم ابریشم، الهام‌بخش ایجاد ساختارهای کامپوزیتی ازجمله بیوکامپوزیت‌هایی بی‌بافت با وزن کم و مقاومت بالا است. در پژوهش حاضر، با روش تحلیلی–توصیفی و استدلال منطقی تلاش می‌شود ضمن معرفی ساختار پیله­ی ابریشم، با بهره‌گیری از سریسین پیله ابریشم و الیاف طبیعی که به دلایل مختلف ازجمله سبکی، عدم آلودگی، فراوانی و کم‌هزینه بودن، می‌تواند جایگزینی مناسب برای الیاف مصنوع باشد، مصالحی به‌عنوان یک بیوکامپوزیت بی‌بافت، پیشنهاد گردد. این مصالح خاصیت بازیافت‌پذیری دارد‌ و از منظر پایداری و مصرف انرژی مناسب است و می­تواند به‌عنوان عایق رطوبتی و حرارتی مورداستفاده قرار گیرد. این عملکرد در پوسته­ی خارجی ساختمان و با استفاده از پلاگین تحلیل انرژی هانی بی و در محیط گرس‌هاپر، برای اقلیم گرم و خشک شهر کاشان، شبیه‌سازی و تحلیل‌شده است. نتایج نشان‌دهنده آن است که کامپوزیت بی‌بافت از الیاف طبیعی پیشنهادشده می‌تواند تا 12.7 درصد ‌به بهبود عملکرد حرارتی و کاهش انتقال حرارت بین فضای بیرون و درون ساختمان نسبت به زمانی که پوسته ساختمان بدون عایق حرارتی در نظر گرفته شود، کمک کند.

Assessment of mechanical properties of flax fiber reinforced with Delrin polymer composite

In the material industry, composites are sought after as more affordable and environmentally friendly materials, they play a vital role. Fiber-reinforced polymer composites exhibit excellent mechanical and tribological properties. One of the natural fibers that are both lightweight and biodegradable is flax. However, the mechanical qualities of natural fiber lag behind those of synthetic fiber. To enhance the structural or mechanical application of hybridization, it is therefore important to study the mechanical properties of natural fiber. The mechanical characteristics of natural flax fibre composite materials reinforced with Delrin matrix material are the foundation of the current review. In this work, static mechanical tests like tensile, impact testing and dynamic mechanical tests like wear test, Shore ‘D’ hardness, flexural and compression properties are evaluated for the Delrin as the matrix and the chopped flax fiber as the reinforcement. Measured mechanical test results showed an incremental increase with the addition flax/Delrin. According to the finding’s, non-reinforced epoxy has inferior characteristics to Flax + Delrin composite materials. Making hybrid composites out of natural fiber and Delrin in the future could bring in a new era for composite materials. This improves the performance and degrading life of composite.

Investigation and optimization of wear properties of flax fiber reinforced Delrin polymer composite

Nowadays, the significance of natural fiber hybrid composites shows increasing trend in the automobile industry. New high-performance polymer materials can be produced from natural fibers which are inexpensive, renewable, eco-friendly, and biodegradable. Because of renewability, natural fibers can be an alternative source to synthetic fibers as a reinforcing agent. This research work looks at flax fiber natural composite material reinforced with matrix material. For a wide range of applications, delrin offers viable replacements for metal composites. In the present work, composites were prepared by injection molding and investigated. The composite constituents were chopped natural flax fiber as reinforcement (5%, 10%, 15% and 20%) and delrin as the matrix (95%, 90%, 85% and 80%). Pin-on-disc (POD) wear tests were conducted to reveal wear strength of the composite under various POD parameters, optimization is done through the hybrid grey relational and principal component analysis approach. The results showed that composite material (Flax+Delrin) shows improved wear strength compared to the non-reinforced material.

An Old World leaf-cutting, fungus-growing ant: A case of convergent evolution.

The African myrmicine ant Crematogaster clariventris is a territorially dominant arboreal species that constructs very hard carton nests. Noting that workers cut off leaves from different plant species while building or repairing their nests, we asked ourselves if there was a correlation. We conducted scanning electron microscopic observations of nest walls that revealed the presence of fungal mycelia. As the presence of filamentous Ascomycota has been shown on arboreal ant nests worldwide, we used a metabarcoding approach and, indeed, noted the presence of Operational Taxonomic Unit (OTU) Cre_006041 of the Capnodiales known to reinforce large nests of an unidentified African Crematogaster. This OTU was also recorded in the workers' bodies. At a very low level, we also noted OTU Cre_320021 of the Chaetothyriales known for their relationships with the African plant-ant species C.margaritae. Therefore, by cutting leaves and growing fungus, C.clariventris illustrates a case of convergent evolution with higher New World leaf-cutting, fungus-growing Attina of the genera Acromyrmex, Amoimyrmex and Atta. However, there are notable differences. Leaf-cutting Attina cultivate Agaricaceae (Basidiomycota) for food, whereas C.clariventris uses Capnodiales to reinforce their nests (i.e., after the mycelium died, the hyphae's cell walls remained sturdy forming a natural composite material), have a distinct geographical origin (i.e., New World vs. Old World) and belong to a distinct ant tribe in the subfamily Myrmicinae (i.e., Attini vs. Crematogastrini). Furthermore, leaf-cutting Attina evolved an efficacious means of cutting leaves by using their mandibles asymmetrically, whereas C.clariventris workers, typically, use their mandibles symmetrically.

Influence of the Compression Molding Temperature on VOCs and Odors Produced from Natural Fiber Composite Materials

In the automotive sector, the use of nonwoven preforms consisting of natural and thermoplastic fibers processed by compression molding is well known to manufacture vehicle interior parts. Although these natural fiber composites (NFCs) have undeniable advantages (lightweight, good life cycle assessment, recyclability, etc.), the latter release volatile organic compounds (VOCs) and odors inside the vehicle interior, which remain obstacles to their wide deployment. In this study, the effect of the compressing molding temperature on the VOCs and odors released by the flax/PP nonwoven composites was examined by heating nonwoven preforms in a temperature range up to 240 °C. During the hot-pressing process, real-time and in situ monitoring of the composite materials’ core temperature has been carried out using a thermocouples sensor. A chemical approach based on headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography—mass spectrometry (GC-MS) was used for the VOCs analysis. The olfactory approach is based on the odor intensity scale rated by expert panelists trained in olfaction. The results demonstrate marked changes in the VOCs composition with temperature, thus making it possible to understand the changes in the NFCs odor intensity. The results allow for optimizing the molding temperature to obtain less odorous NFC materials.

Pengaruh Fraksi Volume Terhadap Kekuatan Tarik Pada Serat Resam Menggunakan Resin Polyester BQTN-EX

Along with the times, the technology of utilizing natural fiber composite materials has developed, including in the field of engineering materials. One of them is natural fiber. This resam plant is easy to get because it is used in almost all corners of Indonesia, including the Bangka Belitung province because it is easy to process, and has stem content and stem size. The purpose of this study was to determine the best value for the effect of volume fraction on the tensile test of resam fiber composite materials. This study used a volume fraction variant of 10%, 15% and 20% by immersion in NaOH for 30, 60 and 90 minutes. The highest average results were obtained from the tensile test obtained from the 15% volume fraction with 60 minutes of NaOH immersion and the lowest average values were obtained from the 15% volume fraction with 90 minutes of NaOH immersion. From the research results obtained, it was concluded that the average value and variance of the tensile strength of resam fiber was found at the level 2 immersion time factor, which was for 60 minutes and the level 2 volume fraction factor, which was 15%. volume fraction, the most optimal.

Novel eco-friendly dye-polymer composite films for white LEDs: Syntheses, structures and luminescence properties

Natural luminescent dyes exhibit great potential in white light-emitting diodes (LEDs) due to their non-toxicity, low cost, and environmental compatibility. However, traditional natural luminescent dyes show aggregation-caused quenching and thermally unstable luminescence. Therefore, developing novel natural luminescent dye-based composite materials to overcome these limitations is highly desirable for white LEDs. In this work, BBR-PVA composite films are synthesized with different BBR concentrations through a simple dip-coating method. The structures and luminescent properties of BBR-PVA composite films are investigated. Results demonstrate the formation of BBR J-aggregates in the composite, enhancing the luminescence of BBR-PVA composite films. The presence of intermolecular H-bonds between BBR and PVA molecules improves luminescent thermal stability. Moreover, the relative contributions of BBR J-aggregation and H-bonding interactions to the luminescence of the composites are tuned by varying the BBR concentration. The white LED fabricated using a blue chip and the as-synthesized BBR-PVA composite film shows good luminescence performance at 2.7 V and a driving current of 57 mA. The CIE chromaticity coordinates, the correlated color temperature, color rendering index, and luminous efficiency are (0.32, 0.25), 7238 K, 75 and 12 l m/W, respectively.

Numerical simulation of fracture mechanisms due to directional shrinkage in natural composites

The use of natural composites in modern engineering applications has numerous benefits owing to their excellent sustainable attributes and negligible environmental impacts. The full commercialization of natural composites as alternative materials to conventional ones is undermined by environmental factors such as moisture content leading to varied shrinkage and swelling behaviors. Uncontrolled shrinkage behavior can often lead to premature split in natural composites. The aim of this study is to investigate the fracture mechanisms due to directional shrinkage in natural composite material through numerical simulation by considering the finite element modelling software of LS-DYNA. From numerical results, directional shrinkage could be seen to clearly affect the fracture patterns in natural composites as compared to the control one. The fracture patterns, which indicated a narrowed region of stress concentration in the material, is assumed to emanate from internally induced forces in the material, namely tensile and compressive forces. This specific pattern is associated to longitudinal split failure typically observed in orthotropic materials. Results of this study can be useful to further investigate the complex fracture behavior in natural composite materials to better understand their durability limitations.

Mechanical properties variation of cortical bone with type of loading using FEM

Bone is known to be a natural composite material with variation of mechanical properties depending on the location and orientation of specimen extracted. In this study, specimens of cortical bone extracted from three different locations and two different orientations were modelled in Abaqus by considering the material of cortical bone to be anisotropic in nature. The stress–strain curves of specimens for both transverse and longitudinal orientation for compressive and tensile testing has been plotted. It has been found from the curves that the specimen belonging to upper diaphysis has more values of mechanical properties in comparison to other specimen-type for both compressive and tensile testing. It has also been observed that the compressive test shows more value of yield stress, elastic modulus and ultimate stress in comparison to tensile test that is the cortical bone can wear more load in the compressive direction. The values of mechanical properties found to be more for longitudinal orientation in comparison to transverse orientation. The results obtained found a good relation with the existing literature.

Structural Analysis of Airplane Wing Using Composite and Natural Fiber Materials: A Survey

Abstract: Natural fiber-reinforced polymer-based composites are increasingly used in modern society due to their numerous benefits for uses in mechanical engineering. Polymer-based composite materials are widely employed in civil construction, automotive, aerospace, and many other industries due to their many benefits. Natural fibers can be used to create new, highperformance polymer materials because they are affordable, environmentally friendly, renewable, and partially and fully biodegradable. Examples of these fibers include EGR Glass R Glass, Carbon fiber, and S Glass, as well as kenaf, pineapple, sugarcane, hemp, oil palm, flax, and leaf. The purpose of this study is to explore the use of natural fibers and composites in the production of airplane wings, including mechanical characteristics, applications, and potential as well as problems and future demand for natural composite materials for engineering uses. A good 50% of the airspace's components are natural composites. Because natural composites have the ability to lower aircraft weight, they are currently being used to construct helicopters, military fighter aircraft, small and large civil transport aircraft, cockpits, satellites, launch vehicles, and missiles. Rudder, spoilers, LG doors, keel beam, airbrakes, elevators, turbine engine fan blades, propellers, rear bulkhead, wing ribs, main wings, interior fixtures, etc. Composites made of natural fibers are attractive and promising. The use of natural fiber-based composite materials is growing daily due to their strength and integrity. The natural fiber is a renewable, environmentally beneficial, and biodegradable raw material. Both its mechanical and thermal insulation qualities are strong in natural fiber. However, the loading placed on the natural fiber and its youthful modulus determines its strength In addition to discussing the benefits of natural fibers over other materials, this paper provides a description of the several types of natural fiber, their physical and mechanical properties, and their advantages.

Potential of natural fiber composite materials for bulletproof vest applications

The bulletproof vest material that is often used is a composite material. Composites are a mixture of two or more material elements, with different mechanical properties, which aim to obtain new materials that have better mechanical properties than the constituent materials. One alternative mixture of materials in composite materials is to use natural fibers as a substitute for kevlar fibers. In Indonesia, which has a tropical climate, natural fibers are very easy to obtain from various kinds of plants found in Indonesia. Along with the many plants obtained, a lot of waste is also produced because of this. So research was conducted on the utilization of the potential of natural fibers for alternative composites. With the experimental method, from the results of the experiment, the results obtained from the five natural fibers that have been discussed, namely pineapple leaf fiber, water hyacinth fiber, bark fiber, hemp fiber, and bamboo fiber, only pineapple leaf fiber has not met the National Institute of Justice (NIJ) standard, while the other four natural fibers have met the NIJ standard for bulletproof vests.

A comprehensive review of natural fiber reinforced composite and their modern application

The industrial sector heavily depends on materials. According to the Kyoto Protocol, enterprises are becoming more and more interested in obtaining carbon credits through lowering air pollution. Therefore, green composite materials must be used in place of conventional materials to complete the carbon credit. Natural fiber-reinforced composite materials are now widely utilized in contemporary industrial sectors for example sports, automotive, medicine, aerospace, electronics, food packaging, and energy storage where engineered heterogeneity has been developed and utilized to achieve specific engineering functions. Because of its exceptional mix of thermal, mechanical, and dielectric qualities as well as environmental benefits including renewability and biodegradability, natural cellulosic fiber composite materials are becoming more and more popular for a variety of industrial applications. Natural cellulosic fiber-reinforced composite mechanical and thermal properties as well as for natural fibers mechanical properties and thermal properties also interpreted in this article.

Tensile Behaviour of Natural Polymer Composite Materials at Ambient and Elevated Temperatures

Tensile Behaviour of Natural Polymer Composite Materials at Ambient and Elevated Temperatures

Analysis of Drilling Behaviour in Jute Fibres Reinforced Natural Composites

ABSTRACT In the study, Natural jute composite materials, which have environmental advantages due to their easily degradable nature were drilled with different processing parameters and the effects of thrust force, vibration and temperature changes on hole quality were investigated. The effect of feed and spindle speed was statistically analyzed using ANOVA method. The thrust force, vibration and temperature factors that occur depending on the drilling parameters vary and affect the roughness and delamination values. The effect of feed and speed on thrust force was calculated as 97.87% and the feed effect (90.85%) is far greater than the speed (9.15%). The effect of drilling parameters on vibration is statistically insignificant due to the different spread behavior in the layers of the composite material (R2 = 0.2329). However, feed effect on vibration (94.6%) is greater than the speed effect (6.06%). The temperature is affected by 96.93% of the drilling parameters and the speed is 84.16% and the feed is 15.83%. The roughness effect depending on the drilling parameters is measured as 84.91%. The effect of speed on roughness (90.26%) is greater than the feed (9.73%). It has been determined that this situation is mostly related to vibration and temperature.