Comparative Analysis of the Tensile Properties of Polyester and Epoxy Composites Reinforced with Hemp Fibers

2018 ◽  
Vol 930 ◽  
pp. 201-206
Author(s):  
Lazaro Araújo Rohen ◽  
Anna Carolina Cerqueira Neves ◽  
Jheison Lopes dos Santos ◽  
Lucio Fabio Cassiano Nascimento ◽  
Sergio Neves Monteiro ◽  
...  

The present work compares the tensile properties of polyester and epoxy matrix composites reinforced with hemp fibers. Polyester and epoxy reinforced with different volume fractions of hemp fibers up to 30% were prepared according to ASTM D-638-14 and tensile tested. The epoxy matrix composites reinforced with 30% of fibers presented tensile strength of 53 MPa, while those of polyester matrix, 25 MPa. The elastic modulus of the epoxy matrix composites was 1.75 GPa and that of the polyester matrix 4.05 GPa. The tests showed that the resistance of the epoxy composites reinforced with hemp fiber is superior to those of polyester matrix. However, the stiffness of the polyester/hemp fiber composites is higher than the epoxy/hemp fiber ones.

2014 ◽  
Vol 775-776 ◽  
pp. 284-289 ◽  
Author(s):  
Sergio Neves Monteiro ◽  
Frederico Muylaert Margem ◽  
Wellington Pereira Inácio ◽  
Artur Camposo Pereira ◽  
Michel Picanço Oliveira

The tensile properties of DGEBA/TETA epoxy matrix composites reinforced with different amounts of sisal fibers were evaluated. Composites reinforce with up to 30% in volume of long, continuous and aligned sisal fibers were room temperature tested in an Instron machine. The fracture was analyzed by SEM. The results showed significant changes in the mechanical properties with the amount of sisal fibers. These mechanical properties were compared with other bend-tested composites results. The fracture analysis revealed a weak fiber/matrix interface, which could be responsible for the performance of some properties.


2016 ◽  
Vol 869 ◽  
pp. 249-254
Author(s):  
Lazaro Araújo Rohen ◽  
Anna Carolina Cerqueira Neves ◽  
Frederico Muylaert Margem ◽  
Carlos Maurício Fontes Vieira ◽  
Fabio de Oliveira Braga ◽  
...  

The use of natural fibers as reinforcement in polymer matrix composites is replacing the use of synthetic fibers, especially from an environmental standpoint. Indeed, natural fibers are biodegradable and renewable, with no aggression to the environment. Moreover, they are worldwide abundant with relatively low cost. It was found that fine fibers of sisal, with the thinnest diameters can achieve tensile strength on the order of 1000 MPa. In this work, tensile specimens were prepared with 30% in volume of sisal fibers with diameters between 0.1 and 0.10mm incorporated in a continuous and aligned way into epoxy matrix. The results showed a significant increase in tensile strength and elastic modulus of the composites as a function of the incorporated amount of thinner sisal fibers.


2012 ◽  
Vol 06 ◽  
pp. 191-196
Author(s):  
KE LIU ◽  
HITOSHI TAKAGI ◽  
ZHIMAO YANG

Manila hemp fibers are separated to several sequent fragments from single fiber. The tensile strength of each fiber fragments and their epoxy composite are measured, followed by scanning electronic microscopic (SEM) analysis. The results show that the tensile strength of fiber fragments is almost constant along fiber. For composite, the tensile strength first increases and then decreases at the position near to root. The Young's modulus presents increasing with location from root to top for fiber and composite. Microstructure analysis indicates that the difference of tensile properties between fiber fragments derive from the difference of fiber diameter.


2016 ◽  
Vol 869 ◽  
pp. 361-365 ◽  
Author(s):  
Sergio Neves Monteiro ◽  
Frederico Muylaert Margem ◽  
Noan Tonini Simonassi ◽  
Rômulo Leite Loiola ◽  
Michel Picanço Oliveira

In recent years natural fibers, especially those lignocellulosic extracted from plants, have gained attention owing to their engineering performance as polymer composite reinforcement. It was found that some of these lignocellulosic fibers, such as the curaua, ramie and sisal may reach tensile strength above 1000 MPa in association with very thin diameters. Therefore. the objective of the present work was to fabricate polyester matrix composites with the highest tensile strength possible, by reinforcing with the thinnest continuous and aligned curaua fibers. Tensile tests results of composites reinforced with 30% volume of these thinnest curaua fibers showed a tensile strength of 135 MPa, which corresponds to one of the highest strength attained for lignocellulosic fiber composites.


2015 ◽  
Vol 799-800 ◽  
pp. 115-119 ◽  
Author(s):  
Anika Zafiah M. Rus ◽  
Nur Munirah Abdullah ◽  
M.F.L. Abdullah ◽  
M. Izzul Faiz Idris

Graphite reinforced bio-based epoxy composites with different particulate fractions of graphite were investigated for mechanical properties such as tensile strength, elastic modulus and elongation at break. The graphite content was varied from 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.% by weight percent in the composites. The results showed that the mechanical properties of the composites mainly depend on dispersion condition of the treated graphite filler, aggregate structure and strong interfacial bonding between treated graphite in the bio-based epoxy matrix. The composites showed improved tensile strength and elastic modulus with increase treated graphite weight loading. This also revealed the composites with increasing filler content was decreasing the elongation at break.


2014 ◽  
Vol 775-776 ◽  
pp. 308-313 ◽  
Author(s):  
Sergio Neves Monteiro ◽  
Frederico Muylaert Margem ◽  
Lucas Barboza de Souza Martins ◽  
Rômulo Leite Loiola ◽  
Michel Picanço Oliveira

Fibers of the giant bamboo (Dendrocalmus giganteus) are amongst the strongest lignocellulosic fibers. Although studies have been already performed, limited information exists on the mechanical properties of polymeric composites reinforced with continuous and aligned giant bamboo fibers. This work evaluates the tensile strength of this type of composite. Standard tensile specimens were fabricated with up to 30% of fibers aligned along the specimen length. The fibers were press-molded with a commercial polyester resin mixed with a hardener and cured for 24 hours at room temperature. The specimens were tensile tested in an Instron machine and the fracture surface analyzed by scanning electron microscopy. The tensile strength increased significantly with the amount of giant bamboo fiber reinforcing the composite. This performance can be associated with the difficult of rupture imposed by the fibers as well as with the type of cracks resulting from the bamboo fiber/polyester matrix interaction, which prevents rupture to occur.


2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.


Author(s):  
Asma Ul Hosna Meem ◽  
Kyle Rudolph ◽  
Allyson Cox ◽  
Austin Andwan ◽  
Timothy Osborn ◽  
...  

Abstract Digital light processing (DLP) is an emerging vatphotopolymerization-based 3D-printing technology where full layers of photosensitive resin are irradiated and cured with projected ultraviolet (UV) light to create a three-dimensional part layer-by-layer. Recent breakthroughs in polymer chemistry have led to a growing number of UV-curable elastomeric photoresins developed exclusively for vat photopolymerization additive manufacturing (AM). Coupled with the practical manufacturing advantages of DLP AM (e.g., industry-leading print speeds and sub-micron-level print resolution), these novel elastomeric photoresins are compelling candidates for emerging applications requiring extreme flexibility, stretchability, conformability, and mechanically-tunable stiffness (e.g., soft robotic actuators and stretchable electronics). To advance the role of DLP AM in these novel and promising technological spaces, a fundamental understanding of the impact of DLP manufacturing process parameters on mechanical properties is requisite. This paper highlights our recent efforts to explore the process-property relationship for ELAST-BLK 10, a new commercially-available UV-curable elastomer for DLP AM. A full factorial design of experiments is used to investigate the effect of build orientation and layer thickness on the quasi-static tensile properties (i.e., small-strain elastic modulus, ultimate tensile strength, and elongation at fracture) of ELAST-BLK 10. Statistical results, based on a general linear model via ANOVA methods, indicate that specimens with a flat build orientation exhibit the highest elastic modulus, ultimate tensile strength, and elongation at fracture, likely due to a larger surface area that enhances crosslink density during the curing process. Several popular hyperelastic constitutive models (e.g., Mooney-Rivlin, Yeoh, and Gent) are calibrated to our quasi-static tensile data to facilitate component-level predictive analyses (e.g., finite-element modeling) of soft robotic actuators and other emerging soft-matter applications.


2020 ◽  
Vol 305 ◽  
pp. 28-35
Author(s):  
Anslem Wong Tsu An ◽  
Sujan Debnath ◽  
Vincent Lee Chieng Chen ◽  
Moola Mohan Reddy ◽  
Alokesh Pramanik

In recent years, studies regarding natural fiber reinforced composites have been increased as they are biodegradable with good mechanical performance therefore can help to overcome the environmental issue. As the natural fibers are easy to obtain, many industries have started to make use of natural fiber composites which are light in weight and possess good mechanical properties. However, the natural fiber composites also possess certain limitations most importantly their high moisture absorption ability which makes them incompatible at degradable environment. The fiber constituents of natural fiber composite may have different type of interactions at different environmental conditions. In addition, the involvement of nanoparticles in the composite may be the solution to overcome the deficiencies. In this research, the degradation behaviour of Oil palm empty fruit bunch (OPEFB) fibers reinforced epoxy composites upon exposure to degradable environmental conditions and the effect of adding nanoparticles have been studied. The tensile tests were conducted before and after the exposure to different environmental conditions including plain water, moist soil, brine solution, and cooking oil. Results shows that the addition of 10wt% of OPEFB fiber to the epoxy composites had improved the mechanical tensile strength up to 15.97% and composites exposed to brine solution have the most prominent sign of degradation in mechanical properties in both composites with and without nanosilica. Nevertheless, the composites with nanosilica have shown up to 24.28% improvement in tensile strength after exposure to different environmental conditions. The improvement were attributed due to filling the voids of the composites with nanosilica and good interfacial adhesion between the nanofiller, fiber, and matrix.


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