scholarly journals MECHANICAL CHARACTERIZATION OF A POLYESTER MATRIX COMPOSITE REINFORCED WITH NATURAL FIBERS FROM Luffa cylindrica Hoen

Nativa ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 558-562
Author(s):  
Edgley Alves de Oliveira Paula ◽  
Rafael Bezerra Azevedo Mendes ◽  
Claudia Yanara Meira da Costa ◽  
Rafael Rodolfo de Melo ◽  
Alexandre Santos Pimenta ◽  
...  

The growing demand for renewable products has led to many studies of alternative materials. The present work describes the production of a composite based in polyester resin reinforced with fibers from the climber plant Luffa cylindrica and evaluates its mechanical performance. The composite was produced with two perpendicularly-crossed layers of vegetable fibers. The lamination was performed in a mold with two glass plates pressed by a hydraulic press. To characterize the properties of the produced composite, density, tensile and bending strength tests were performed. The final composite had a mean density of 1.16 g cm-3, making it light due to the reinforcement with vegetable fibers. Tensile and bending strengths were 13.91 and 26.70 MPa, respectively. The experimental results showed that the composite with vegetable fibers as reinforcement had lower density than the pure polyester matrix and composites produced with glass fibers. The tensile strength was higher than the polyester matrix itself, although it was still low. Also, when submitted to bending stress, the composite presented lower resistance than the matrix. Overall, the composite can be a viable alternative for non-structural applications where light materials are required such as handicrafts and office partition. Keywords: sustainable material; vegetable fibers; mechanical properties; technical feasibility.   Caracterização mecânica de um compósito com matriz de poliéster reforçado com fibras naturais de bucha vegetal (Luffa cylindrica Hoen)   RESUMO: A crescente demanda por produtos renováveis tem levado a muitos estudos de materiais compósitos reforçado com fibras vegetais. A planta trepadeira Luffa cylindrica, conhecida popularmente como bucha vegetal, também apresenta potencial para este uso. O presente trabalho avalia o desempenho de um compósito à base de resina de Poliéster reforçado com bucha vegetal. O compósito foi produzido com duas camadas de fibras vegetais dispostas perpendicularmente entre si. A laminação foi realizada em um molde com duas placas de vidro prensadas por uma prensa hidráulica. Como propriedade física foi determinada a densidade e para as propriedades mecânicas, foram realizados ensaios de resistência à tração e flexão. O compósito final apresentou densidade média de 1,16 g cm-3, tornando-o leve devido ao reforço com fibras vegetais. As resistências à tração e flexão foram de 13,91 e 26,70 MPa, respectivamente. Os resultados experimentais mostraram que o compósito com fibras vegetais como reforço apresentou densidade menor que a matriz de poliéster pura e compósitos produzidos com fibras de vidro. A resistência à tração foi maior do que a própria matriz de poliéster. Além disso, quando submetido a tensões de flexão, o compósito apresentou menor resistência do que a matriz. No geral, o composto pode ser uma alternativa viável para aplicações não estruturais onde materiais leves são necessários, como artesanatos e paredes divisórias. Keywords: material sustentável; fibras vegetais; propriedades mecânicas; viabilidade técnica.

2018 ◽  
Vol 2 ◽  
pp. 145-154 ◽  
Author(s):  
Viviane Costa Correia ◽  
Sergio Francisco Santos ◽  
Holmer Savastano Jr ◽  
Vanderley Moacyr John

Vegetable fibers produced from agroindustrial resources in the macro, micro and nanometric scales have been used as reinforcement in cementitious materials. The cellulosic pulp, besides being used as the reinforcing element, is also the processing fiber that is responsible for the filtration system in the Hatcheck method. On the other hand, the nanofibrillated cellulose has the advantage of having good mechanical performance and high specific surface, which contributes to improve the adhesion between fiber and matrix. In the hybrid reinforcement, with micro and nanofibers, the cellulose performs bonding elements with the matrix and acts as stress transfer bridges in the micro and nano-cracking network with the corresponding strengthening and toughening of the cementitious composite. Some strategies are studied to mitigate the degradation of the vegetable fibers used in cost-effective and non-conventional fiber cement, as well as to reach a sustainable fiber cement production. As a practical example, the accelerated carbonation curing at early age is a developing technology to increase the durability of composite materials: it decreases porosity, promotes a higher density in the interface generating a good fiber–matrix adhesion and a better mechanical behavior. Thus, the vegetable fibers are potentially applicable to produce high mechanical performance and sustainable cementitious materials for use in the Civil Construction.


2020 ◽  
Vol 15 (1) ◽  
pp. 113-128
Author(s):  
Chouaib Aribi ◽  
Aissa Bouaissi ◽  
Brahim Safi ◽  
Mohammed Saidi

Abstract This paper presents an experimental investigation on the post-repair flexural response of mortars with and without damage. In order to improve the mechanical properties of the damaged mortars, which were subjected to different loads ranging between 40 % and 90 %, the mortars specimens were reinforced and repaired using two different composite materials, the first with only epoxy resin, while the second consisted of a mixture of epoxy resin and glass fiber. The results show a significant improvement in the stiffness damaged. Therefore, the reinforced specimens by a layer of resin on the lower side surface increased the bending strength by 58 %, when compared to those control samples. The reinforcement using composite resin-fiber of glass exhibited considerable increases in the safety of constructions. The SEM images of damaged samples with and without repair, revealed the impact of reinforced glass fibers-mortar on the matrix-mortar by improving theirs mechanical performances.


2021 ◽  
Vol 16 (2) ◽  
pp. 55-66
Author(s):  
Mokhtar Rachedi ◽  
Abdelouahed Kriker

Abstract The negative impact of the production and use of building materials on the environment has become evident, so in recent decades, to find more sustainable, eco-friendly, and low-cost materials, the last research tends to reconsider the use of natural fibers and traditional building materials. This paper aims to develop a bio-composite based on the southern Algerian region's local materials consisting mainly of plaster and waste from date palm trees. Many properties were examined experimentally through previous research of our team (physical, mechanical, and microstructure characteristics) [1, 2] to characterize these materials. Several samples of bio-composite of plaster configurations with short length (20mm) and eight-weight ratios (0.5% - 4%) of palm fibers were prepared for mechanical, thermal, and physical characterizations. In addition, tested all previous properties on the specimens after 28 days of curing in normal conditions. The results show a clear improvement in the bio-composites mechanical performance (an increase in the bending strength with achieving compressive strength) and their thermal properties, which have been well developed (density, thermal conductivity, and specific heat capacity). To enhance the resistance of palm fibers to chemical degradation in the plaster's alkaline environment and improve the adhesion between them, these fibers were treated with a NaOH solution of 1% concentration. The plaster's composites reinforced with date palm fibers can be qualified as eco-friendly and thermal insulation building materials.


2020 ◽  
Vol 54 (22) ◽  
pp. 3125-3142
Author(s):  
Romeu RC da Costa ◽  
Eduardo S Sato ◽  
Marcelo L Ribeiro ◽  
Ricardo de Medeiros ◽  
André FC Vieira ◽  
...  

A novel eco-friendly composite material made of polyurethane derived from castor oil reinforced with long cotton fibers was developed. A set of comparative analyses comprising static and dynamic tests was established using specimens made of castor oil-based polyurethane reinforced by glass fibers, and epoxy reinforced by glass and cotton fibers. The manufacturing method and estimation of fiber volume fraction of the specimens were described in detail. Tensile and flexural tests were performed to evaluate the mechanical performance of the novel laminate. Fractographic post-mortem examinations assessed the quality of the fiber–matrix interaction and allowed direct observation of the failure modes. Surface treatment of natural fibers appears necessary to improve the adhesion of the natural fibers to the matrix. Dynamic responses are discussed, considering natural frequencies and modal damping coefficients. In this context, the potentialities and the limitations of using the novel eco-friendly composite material as structural parts are discussed.


2012 ◽  
Vol 626 ◽  
pp. 989-992 ◽  
Author(s):  
Atiqah Afdzaluddin ◽  
Md Abdul Maleque ◽  
Mohammed Iqbal

This paper presents the synergistic effect on flexural properties of kenaf-glass (KG) mat reinforced unsaturated polyester (UPE) hybrid composite which can compounded using sheet molding compound (SMC) process. The matrix is kept constant with 70 % volume fraction while kenaf and glass fibers were varied, such as 7.5/22.5 v/v, 15/15 v/v and 22.5/7.5 v/v. The 30 % kenaf and 30 % glass are also used for the preparation of composite materials. The kenaf mat was treated with 6% sodium hydroxide (NaOH) diluted solution for 3 hours. This mercerization process improved the interface by interacting with both the fiber and its matrix. The flexural test was performed using ASTM D790-03 standard. The study showed with the addition of kenaf and glass mat 15/15 v/v, the optimum flexural properties was obtained compared to other composition. This can be concluded that 15/15 v/v KG mat reinforced unsaturated polyester hybrid composite is the most appropriate hybrid composite which can be considered for many engineering structural applications mainly in automotive panel, bottom structure and bumper beam.


2022 ◽  
Vol 8 ◽  
Author(s):  
Sebastian Dahle ◽  
Kavyashree Srinivasa ◽  
Jure Žigon ◽  
Arnaud Maxime Cheumani Yona ◽  
Georg Avramidis ◽  
...  

The use of wood-based materials in building and construction is constantly increasing as environmental aspects and sustainability gain importance. For structural applications, however, there are many examples where hybrid material systems are needed to fulfil the specific mechanical requirements of the individual application. In particular, metal reinforcements are a common solution to enhance the mechanical properties of a wooden structural element. Metal-reinforced wood components further help to reduce cross-sectional sizes of load-bearing structures, improve the attachment of masonry or other materials, enhance the seismic safety and tremor dissipation capacity, as well as the durability of the structural elements in highly humid environments and under high permanent mechanical load. A critical factor to achieve these benefits, however, is the mechanical joint between the different material classes, namely the wood and metal parts. Currently, this joint is formed using epoxy or polyurethane (PU) adhesives, the former yielding highest mechanical strengths, whereas the latter presents a compromise between mechanical and economical constraints. Regarding sustainability and economic viability, the utilization of different adhesive systems would be preferable, whereas mechanical stabilities yielded for metal-wood joints do not permit for the use of other common adhesive systems in such structural applications. This study extends previous research on the use of non-thermal air plasma pretreatments for the formation of wood-metal joints. The plasma treatments of Norway spruce [Picea abies (L.) Karst.] wood and anodized (E6/EV1) aluminum AlMgSi0.5 (6060) F22 were optimized, using water contact angle measurements to determine the effect and homogeneity of plasma treatments. The adhesive bond strengths of plasma-pretreated and untreated specimens were tested with commercial 2-component epoxy, PU, melamine-urea formaldehyde (MUF), polyvinyl acetate (PVAc), and construction adhesive glue systems. The influence of plasma treatments on the mechanical performance of the compounds was evaluated for one selected glue system via bending strength tests. The impact of the hybrid interface between metal and wood was isolated for the tests by using five-layer laminates from three wood lamellae enclosing two aluminum plates, thereby excluding the influence of congeneric wood-wood bonds. The effect of the plasma treatments is discussed based on the chemical and physical modifications of the substrates and the respective interaction mechanisms with the glue systems.


2021 ◽  
Vol 23 (3) ◽  
pp. 124-138
Author(s):  
Nataliya Pugacheva ◽  
◽  
Yuri Nikolin ◽  
Tatiana Bykova ◽  
Ekaterina Senaeva ◽  
...  

Introduction. The development of new wear-resistant materials obtained by the method of self-propagating high-temperature synthesis (SHS) is an urgent problem in materials science. The SHS method is most widely used in the field of creating new powder materials. Much less attention has been paid to the production of monolithic non-porous composites. For monolithic composites, it is very important to identify the role of the metal matrix and phase transformations in the process of secondary structure formation after the completion of the synthesis process when the obtained material is cooled. The aim of this work was to carry out a comparative analysis of the structure and properties of SHS composites of the Fe-Ti-C-B, Fe-Ni-Ti-C-B, Fe-Ni-Cr-Ti-C-B, and Cu-TiC-B systems. Materials and research methods. Composites were obtained from powder mixtures consisting of thermoreactive components Ti, C, and B, as well as matrix Fe, Fe-Ni, Fe-Ni-Cr, and Cu. The initial powders were thoroughly mixed, loaded into a steel tube container, and the powder mixture was preliminary compacted. Then, the workpieces were heated in an electric furnace to the temperature of the onset of autoignition. After completion of the SHS, the workpieces were deformed with a force of 250 MPa in a hydraulic press at a temperature not lower than 1000 ° C. Samples were cut from the obtained sandwich plates for microstructural studies, density determination, hardness measurements, transverse bending tests and abrasive wear resistance tests. Results and discussion. All investigated composites were characterized by an uneven distribution of strengthening particles TiC and TiB2 over the volume. The use of the Fe-Ni matrix led to the formation of regions with the γ-Fe + Fe2B eutectic structure in the composite and an additional strengthening phase Ni3Ti. The use of Fe-Ni-Cr metal-matrix components led to the formation of two solid solutions in the matrix - austenite and ferrite, and Cr23C6 particles were formed along the boundaries of austenite grains. The maximum transverse bending strength was shown by SHS composites of the Fe-Ti-C-B and Cu-Ti-C-B systems with a matrix of FCC solid solutions. All composites had a hardness of 66 -72 HRC and showed the same abrasion resistance.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1041 ◽  
Author(s):  
Francisco J. Alonso-Montemayor ◽  
Quim Tarrés ◽  
Helena Oliver-Ortega ◽  
F. Xavier Espinach ◽  
Rosa Idalia Narro-Céspedes ◽  
...  

Automotive and industrial design companies have profusely used commodity materials like glass fiber-reinforced polypropylene. These materials show advantageous ratios between cost and mechanical properties, but poor environmental yields. Natural fibers have been tested as replacements of glass fibers, obtaining noticeable tensile strengths, but being unable to reach the strength of glass fiber-reinforced composites. In this paper, polyamide 6 is proposed as a matrix for cellulosic fiber-based composites. A variety of fibers were tensile tested, in order to evaluate the creation of a strong interphase. The results show that, with a bleached hardwood fiber-reinforced polyamide 6 composite, it is possible to obtain tensile strengths higher than glass-fiber-reinforced polyolefin. The obtained composites show the existence of a strong interphase, allowing us to take advantage of the strengthening capabilities of such cellulosic reinforcements. These materials show advantageous mechanical properties, while being recyclable and partially renewable.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 619
Author(s):  
Ferran Serra-Parareda ◽  
Fabiola Vilaseca ◽  
Francesc X. Espinach ◽  
Pere Mutjé ◽  
Marc Delgado-Aguilar ◽  
...  

Biocomposites are composite materials where at least the matrix or the reinforcement phases are obtained from natural and renewable resources. Natural fibers for composite preparation can be obtained from annual plants, wood, recycled products, or agroforestry waste. The present work selected abaca strands, spruce fibers, recycled fibers from old newspaper, and barley fibers as raw materials to produce biocomposites, in combination with a biobased polyethylene. One very important feature in material science and for industrial applications is knowing how a material will deform under load, and this characteristic is represented by Young’s modulus. Therefore, in this work, the stiffness and deformation of the biocomposites were determined and evaluated using macromechanics and micromechanics analyses. Results were compared to those of conventional synthetic composites reinforced with glass fibers. From the micromechanics analysis, the intrinsic Young modulus of the reinforcements was obtained, as well as other micromechanics parameters such as the modulus efficiency and the length and orientation factors. Abaca strands accounted for the highest intrinsic modulus. One interesting outcome was that recycled fibers exhibited similar Young’s moduli to wood fibers. Finally, agroforestry waste demonstrated the lowest stiffening potential. The study explores the opportunity of using different natural fibers when specific properties or applications are desired.


2021 ◽  
Vol 1045 ◽  
pp. 226-230
Author(s):  
Amit Kumar Thakur ◽  
Ajay Kumar Kaviti ◽  
J. Ronald Aseer

The natural fibers are the alternative to glass and other human-made fibers, because of their low cost and readily available from natural resources and acts as a reinforcing material for the polymer composites. Jute is the most widely used natural fibers among the various fibers due to its superior characteristics. Composite materials are made with different materials that are physically and chemically different alienated by interfaces. In this work, epoxy and polyester hybrid composites reinforced with jute and glass fiber were fabricated by hydraulic press method and their tensile and impact properties were compared. The mechanical properties of jute/glass hybrid composites with different layers such as tensile strength, percentage of elongation and impact strength were evaluated using ASTM specifications. Tensile and Charpy impact test results indicated that jute/glass fiber reinforced epoxy composites have shown optimum properties than polyester composites.


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