Promising Mechanical, Thermal, and Ballistic Properties of Novel Epoxy Composites Reinforced with Cyperus malaccensis Sedge Fiber

Composites reinforced with natural lignocellulosic fibers (NLFs) are gaining relevance as the worldwide demand for renewable and sustainable materials increases. To develop novel natural composites with satisfactory properties, less common NLFs should also be investigated. Among these, the Cyperus malaccensis (CM), a type of sedge fiber, is already used in simple items like ropes, furniture, and paper, but has not yet been investigated as composite reinforcement for possible engineering applications. Therefore, the present work evaluated for the first time the properties of novel epoxy composites incorporated with 10, 20, and 30 vol.% of CM sedge fibers. Tensile, Izod-impact, and ballistic impact tests were performed, as well as Fourier transform infrared (FT-IR) spectroscopy and thermal analysis of the composites. Results disclosed a decrease (−55%) in tensile strengths as compared to the neat epoxy. However, the elastic modulus of the 30 vol.% sedge fiber composite increased (+127%). The total strain and absorbed ballistic energy did not show significant variation. The Izod impact energy of the 30 vol.% composite was found to be 181% higher than the values obtained for the neat epoxy as a control sample. An increase in both stiffness and toughness characterized a reinforcement effect of the sedge fiber. The thermal analysis revealed a slight decrease (−15%) in the degradation temperature of the CM sedge fiber composites compared to the neat epoxy. The glass-transition temperatures were determined to be in the range of 67 to 81 °C.

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Impact Resistance of Epoxy Composites Reinforced with Amazon Guaruman Fiber: A Brief Report

Polymers ◽

10.3390/polym13142264 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2264

Author(s):

Raphael H. M. Reis ◽

Fabio C. Garcia Filho ◽

Larissa F. Nunes ◽

Veronica S. Candido ◽

Alisson C. R. Silva ◽

...

Keyword(s):

Fiber Composite ◽

Impact Resistance ◽

Fiber Composites ◽

Epoxy Composites ◽

Impact Performance ◽

Electron Microscopy Analysis ◽

Ballistic Properties ◽

Microscopy Analysis ◽

Izod Impact ◽

The Impact

Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.

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Comparative Study of a Neat Epoxy and Unidirectional Carbon/Epoxy Composites under Tensile and Impact Loading

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.267.87 ◽

2017 ◽

Vol 267 ◽

pp. 87-92 ◽

Cited By ~ 2

Author(s):

Kakur Naresh ◽

Shankar Krishnapillai ◽

Velmurugan Ramachandran

Keyword(s):

Tensile Properties ◽

Impact Loading ◽

Mechanical Analysis ◽

Epoxy Composites ◽

Neat Epoxy ◽

Impact Machine ◽

Military Vehicles ◽

Cfrp Composites ◽

Laminate Theory ◽

Izod Impact

In the present work, the neat epoxy and different orientations [0°, 45°, 90°, (45°/-45°/45°) s, (±45°/0°/90°) s] of unidirectional carbon/epoxy composites are experimentally studied under tensile and impact loading. The notched impact tests are performed using the Izod impact machine to obtain the energy absorption of neat epoxy and different CFRP composites which is required for effective design of bullet proof jackets and military vehicles. The micro mechanical analysis is employed to determine the shear properties of a matrix using the tensile properties. Using classical laminate theory [CLT], the theoretical tensile properties are determined. The SEM fractography analysis is used to observe the damage mechanisms of neat epoxy and different orientations of CFRP composites subjected to tension and impact loading.

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Effect of Morphology of Calcium Carbonate on Toughness Behavior and Thermal Stability of Epoxy-Based Composites

Processes ◽

10.3390/pr7040178 ◽

2019 ◽

Vol 7 (4) ◽

pp. 178 ◽

Cited By ~ 9

Author(s):

Guijun Yang ◽

Young-Jung Heo ◽

Soo-Jin Park

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Fracture Toughness ◽

Filler Content ◽

Flexural Modulus ◽

Epoxy Composites ◽

Neat Epoxy ◽

Caco3 Nanoparticles ◽

Degradation Temperature ◽

Thermal Stability Of

In this study, the modification of an epoxy matrix with different amounts of cube-like and rod-like CaCO3 nanoparticles was investigated. The effects of variations in the morphology of CaCO3 on the mechanical properties and thermal stability of the CaCO3/epoxy composites were studied. The rod-like CaCO3/epoxy composites (EP-rod) showed a higher degradation temperature (4.5 °C) than neat epoxy. The results showed that the mechanical properties, such as the flexural strength, flexural modulus, and fracture toughness of the epoxy composites with CaCO3 were enhanced by the addition of cube-like and rod-like CaCO3 nanoparticles. Moreover, the mechanical properties of the composites were enhanced by increasing the amount of CaCO3 added but decreased when the filler content reached 2%. The fracture toughness Kic and fracture energy release rate Gic of cube-like and rod-like CaCO3/epoxy composites (0.85/0.74 MPa m1/2 and 318.7/229.5 J m−2, respectively) is higher than the neat epoxy (0.52 MPa m1/2 and 120.48 J m−2).

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Effect of the addition of aliphatic diamine-functionalized carbon nanotubes on the interfacial adhesion of glass fiber/epoxy composites

Textile Research Journal ◽

10.1177/00405175211051952 ◽

2021 ◽

pp. 004051752110519

Author(s):

Yecheng Fan ◽

Shen Ziyue ◽

Shaohua Zeng ◽

Pengpeng Chen ◽

Ying Xu ◽

...

Keyword(s):

Carbon Nanotubes ◽

Glass Fiber ◽

Interfacial Adhesion ◽

Control Sample ◽

Epoxy Composites ◽

Aliphatic Diamine ◽

Uniform Dispersion ◽

Fiber Matrix ◽

Interlaminar Shear ◽

Chain Lengths

To improve the interfacial adhesion of glass fiber (GF)/epoxy composites, the GF surface was treated by dispersing aliphatic diamine-functionalized multi-walled carbon nanotubes (MWCNTs). Carboxyl MWCNTs were first modified by aliphatic diamine with different alkyl chain lengths and then deposited on the surface of GF. The effect of aliphatic diamine chain lengths on the MWCNTs’ dispersion and interfacial properties of resultant composites was investigated in detail. The results showed that uniform dispersion of MWCNTs and strong fiber/matrix interfacial adhesion could be achieved, based on the grafting of 1,8-octanediamine onto MWCNTs. Compared with the control sample, the interlaminar shear, flexural, and tensile strengths of the treated composites increased by 41%, 29%, and 30%, respectively; the interlaminar fracture toughness and storage modulus in the glass region were significantly enhanced; and the glass transition temperature increased by more than 8°C. This work demonstrates that the carbon nanotubes functionalized by appropriate chain lengths of amine modifier can improve the fiber/matrix interfacial interactions and thus enhance the strength, toughness, and stiffness of fiber-reinforced composites.

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Structure Optimization of Optical Fiber Composite Low Voltage Cable Based on Thermal Analysis

2018 IEEE 2nd International Conference on Dielectrics (ICD) ◽

10.1109/icd.2018.8514618 ◽

2018 ◽

Author(s):

Guanshu Sun ◽

Yu Chen ◽

Ahsan Ashfaq ◽

Kai Yao ◽

Jing Yu

Keyword(s):

Thermal Analysis ◽

Optical Fiber ◽

Low Voltage ◽

Fiber Composite ◽

Structure Optimization

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Characterization of continuous Hibiscus sabdariffa fibre reinforced epoxy composites

Polymers and Polymer Composites ◽

10.1177/09673911211060957 ◽

2022 ◽

Vol 30 ◽

pp. 096739112110609

Author(s):

Atik Mubarak Kazi ◽

Ramasastry DVA

Keyword(s):

Fibre Orientation ◽

Stress Transfer ◽

Dynamic Mechanical Properties ◽

Epoxy Composites ◽

Neat Epoxy ◽

Hibiscus Sabdariffa ◽

Sem Images ◽

Fibre Composites ◽

The Matrix

The influence of fibre orientation on physical, mechanical and dynamic mechanical properties of Hibiscus sabdariffa fibre composites has been studied. The composites with longitudinal (0°), transverse (90°) and inclined (45°) fibre orientation were prepared using the hand layup technique. ASTM standards were used for characterization of continuous Hibiscus sabdariffa fibre composites. The composite with longitudinally placed fibres yields improved mechanical characteristics. The addition of longitudinal (0°) oriented continuous Hibiscus sabdariffa fibres to the epoxy enhances tensile strength by 460%, flexural strength by 160% and impact strength by 603% compared to neat epoxy. The longitudinal (0°) fibre oriented composite offers higher resistance to water absorption and thickness swelling compared to other types of composites. All continuous Hibiscus sabdariffa fibre epoxy composites possess an improved storage modulus than the neat epoxy resin. The glass transition temperature of continuous Hibiscus sabdariffa fibre composites is 8%–31% lower than that of neat epoxy. Scanning electron microscopy (SEM) images confirm the existence of voids in the matrix, fibre pullout and crack propagation near the fibre bundle, which indicates the stress transfer between fibre and matrix is non-uniform.

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Assessment of the Physicochemical and Thermal Characterization of Biofield Energy Treated Polylactic-co-glycolic acid (PLGA)

Journal of Analytical Bioanalytical and Separation Techniques ◽

10.15436/2476-1869.19.2026 ◽

2019 ◽

Vol 3 (1) ◽

pp. 1-6

Author(s):

Alice Branton ◽

Mahendra Kumar Trivedi ◽

Dahryn Trivedi ◽

Gopal Nayak ◽

Snehasis Jana

Keyword(s):

Glycolic Acid ◽

Control Sample ◽

Analytical Techniques ◽

Thermal Characterization ◽

Pharmaceutical Formulations ◽

Plga Nanoparticles ◽

Raw Material ◽

Prosthetic Devices ◽

Degradation Temperature ◽

Energy Healing

Polylactic-co-glycolic acid (PLGA) is a biodegradable copolymer. It has many applications in the pharmaceuticals and biomedical industries, but its degradation and stability is a major concern. The objective of this study was to evaluate the influence of the Trivedi Effect® on the physicochemical and thermal properties of PLGA using modern analytical techniques. The PLGA sample was divided into control and Biofield Energy Treated parts. The control sample did not obtain the Biofield Energy Treatment, whereas the treated PLGA was received the Trivedi Effect®-Consciousness Energy Healing Treatment remotely by a renowned Biofield Energy Healer, Alice Branton. The particle size values of the treated PLGA were increased by 8.97%(d10), 8.79%(d50), 4.72%(d90), and 6.61%{D(4,3)}; thus, the surface area of treated PLGA was significantly decreased by 6.84% compared with the control sample. The latent heat of evaporation and fusion of the treated PLGA were significantly increased by 29.60% and 230.93%, respectively compared with the control sample. The residue amount was significantly increased by 21.99% in the treated PLGA compared to the control sample. The maximum thermal degradation temperature of the treated PLGA was increased by 2.30% compared with the control sample. It was concluded that the Trivedi Effect®-Consciousness Energy Healing Treatment might have generated a new form of PLGA which may show better powder flow ability, thermal stability, and minimize the hydrolysis of the ester linkages of PLGA. This improved quality of PLGA would be a better choice for the pharmaceutical formulations (i.e., the drug like simvastatin, amoxicillin, and minocycline loaded PLGA nanoparticles) and manufacturing of biomedical devices, i.e., grafts, sutures, implants, surgical sealant films, prosthetic devices, etc., in the industry using it as a raw material.

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Correlation between Physico-Mechanical Properties of NR-BR Blends in Tire Tread Formulation with their Thermal Behaviors

Rubber Chemistry and Technology ◽

10.5254/1.3548211 ◽

2008 ◽

Vol 81 (2) ◽

pp. 297-317 ◽

Cited By ~ 4

Author(s):

Saeed Taghvaei-Ganjali ◽

Fereshteh Motiee ◽

Farsa Fotoohi

Keyword(s):

Mechanical Properties ◽

Thermal Analysis ◽

Peak Height ◽

Peak Height Ratio ◽

Butadiene Rubber ◽

Height Ratio ◽

Thermal Behaviors ◽

Degradation Temperature ◽

Rubber Compounds ◽

Successful Technique

Abstract Thermal analysis provides a successful technique for the characterization and identification of rubber compounds. In this study, TGA (thermogravimetric analysis) and DTG (TGA derivative) profiles are used to predict and define the physico-mechanical properties of natural rubber — butadiene rubber (NR / BR) blends, using their thermal behaviors. DTG curves of vulcanizate showed that the initial degradation temperature of NR is lower than BR. According to TGA-DTG profiles we have demonstrated two useful factors, ΔTmax (Tmax BR100−Tmax BRX) and peak height ratio of NR-BR blends which are correlated with physico-mechanical properties of blends.

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