Manufacturing of Epoxy Composites Incorporated with Buriti Fibers and Evaluation of Thermogravimetric Behavior

2014 ◽  
Vol 805 ◽  
pp. 460-465 ◽  
Author(s):  
Anderson de Paula Barbosa ◽  
Michel Picanço Oliveira ◽  
Giulio Rodrigues Altoé ◽  
Frederico Muylaert Margem ◽  
Sergio Neves Monteiro
Keyword(s):  
Room Temperature ◽  
Natural Fibers ◽  
Critical Factor ◽  
Epoxy Composites ◽  
Processing Temperature ◽  
Palm Tree ◽  
Technical Application ◽  
Operational Conditions ◽  
Temperature Levels ◽  
Thermogravimetric Behavior

The thermal resistance of natural fibers is a relevant property for technical application associated with relatively high temperature levels. In polymer composites manufacturated with natural fibers the resistance to thermal degradation may become a critical factor not only with respect to processing temperature but also in-service heating operational conditions. In the present work, epoxy composites incorporated with up to 30 vol% of fibers extracted from the petiole of the buriti palm tree were manufactured and evaluated by thermogravimetric analysis, by means of the TG, and its derivative, DTG, curves from room temperature to 700°C. The results showed thermal resistances above 200°C for both the isolated buriti fibers and its manufactured composites.

scholarly journals Synthesis and Characterization of Natural Fibers Reinforced Fiber Epoxy Composites

2015 ◽  
Vol 51 ◽  
pp. 47-53
Author(s):  
U. Mahaboob Basha ◽  
D. Mohana Krishnudu ◽  
P. Hussain ◽  
K. Manohar Reddy ◽  
N. Karthikeyan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Natural Fibers ◽  
Epoxy Composites ◽  
Synthesis And Characterization ◽  
Mechanical And Thermal Properties ◽  
Epoxy System ◽  
Pennisetum Typhoides ◽  
The Matrix ◽  
Reinforced Fiber

In the current work epoxy resin is chosen as matrix, treated Sacharum offinarum ( SugarCane) fiber, Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler are chosen as reinforcement. Room temperature cured Epoxy System filled with Sacharum offinarum fiber and Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler are synthesised by mechanical shear mixer, then kept in a Ultra sonic Sonicator for better dispersion of Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler in the matrix. Different weights of modified Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler (1,2,3,4,5 gm wt) has been incorporated into the Epoxy matrix in order to study the variation of Mechanical and Thermal properties.

scholarly journals Tucum Fiber from Amazon Astrocaryum vulgare Palm Tree: Novel Reinforcement for Polymer Composites

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2259
Author(s):  
Michelle Souza Oliveira ◽  
Fernanda Santos da Luz ◽  
Andressa Teixeira Souza ◽  
Luana Cristyne da Cruz Demosthenes ◽  
Artur Camposo Pereira ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Impact Energy ◽  
Natural Fibers ◽  
Critical Length ◽  
Epoxy Composites ◽  
Synthetic Fiber ◽  
Palm Tree ◽  
Ballistic Performance ◽  
Synthetic Fibers ◽  
Izod Impact

The replacement of synthetic fibers by natural fibers has, in recent decades, been the subject of intense research, particularly as reinforcement of composites. In this work, the lesser known tucum fiber, extracted from the leaves of the Amazon Astrocaryum vulgare palm tree, is investigated as a possible novel reinforcement of epoxy composites. The tucum fiber was characterized by pullout test for interfacial adhesion with epoxy matrix. The fiber presented a critical length of 6.30 mm, with interfacial shear strength of 2.73 MPa. Composites prepared with different volume fractions of 20 and 40% tucum fiber were characterized by tensile and Izod impact tests, as well as by ballistic impact energy absorption using .22 ammunition. A cost analysis compared the tucum fiber epoxy composites with other natural and synthetic fiber reinforced epoxy composites. The results showed that 40 vol% tucum fiber epoxy composites increased the tensile strength by 104% and the absorbed Izod impact energy by 157% in comparison to the plain epoxy, while the ballistic performance of the 20 vol% tucum fiber composites increased 150%. These results confirmed for the first time a reinforcement effect of the tucum fiber to polymer composites. Moreover, these composites exhibit superior cost effectiveness, taking into account a comparison made with others epoxy polymer composites.

A new class of composite materials: Matrix auto-reinforced organic material–MARIOM

1992 ◽  
Vol 7 (8) ◽  
pp. 1990-1992 ◽  
Author(s):  
A. Wyler ◽  
R.T. Markus ◽  
H.J. Wagner ◽  
B. de Castro
Keyword(s):  
Room Temperature ◽  
Matrix Material ◽  
Natural Fibers ◽  
Building Blocks ◽  
Processing Parameters ◽  
Raw Material ◽  
Processing Temperature ◽  
New Class ◽  
Matrix Reinforcement ◽  
Collagenous Fibers

A sort of composite material can be produced from a single kind of natural organic fiber. This has been observed with bovine leather. During the formation process in a die particulated leather fibers were subjected for a period of about 6 min to a pressure of over 100 bar at a processing temperature of between 60 and 200 °C. In this way a portion of these collagenous fibers was plastically deformed and converted into continuous matrix material in which unconverted fibers act as matrix reinforcement. Round, collagenous fibers assumed an angular cross section and became the building blocks of the continuous matrix. This is clearly visible on pictures made with a scanning electron microscope. At a processing temperature of 70 °C and a pressure of 650 bar, applied for 6 min, the maximum compression strength at room temperature is found to be 185 MPa. At these processing parameters Young's modulus is about 2.4 GPa and the bulk density is 1350 kg/m3. Other natural fibers, to be used as organic raw material for the production of composites, are currently under investigation.

Izod Impact Tests with Polyester Matrix Reinforced with Buriti Fibers

2014 ◽  
Vol 775-776 ◽  
pp. 330-335 ◽  
Author(s):  
Sergio Neves Monteiro ◽  
Frederico Muylaert Margem ◽  
Michel Picanço Oliveira ◽  
Giulio Rodrigues Altoé
Keyword(s):  
Room Temperature ◽  
Natural Fibers ◽  
Impact Resistance ◽  
Palm Tree ◽  
Propagation Behavior ◽  
Mauritia Flexuosa ◽  
Polyester Matrix ◽  
Izod Impact ◽  
The Impact ◽  
Crack Propagation Behavior

The buriti palm tree (Mauritia flexuosa) has, in its petiole, natural fibers with great potential for reinforcement of polymer composites. This work attempts to evaluate the impact resistance of this type of fiber reinforcing polyester matrix. The fibers were mixed with polyester resin under pressure in a metallic mold, and cured at room temperature for 24 hours. Specimens were prepared with fiber percentages varying from 0 to 30% in volume. These specimens were tested in an Izod impact pendulum and the fracture surfaces were examined by scanning electron microscopy, SEM. The impact resistance increased substantially with the relative amount of buriti fiber reinforcing the composite. This performance was associated with the resistance imposed by the fibers and the crack propagation behavior.

Interactions Between Al and Cr Thin Films

1976 ◽  
Vol 34 ◽  
pp. 638-639
Author(s):  
R. M. Anderson ◽  
T. M. Reith ◽  
M. J. Sullivan ◽  
E. K. Brandis
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Vacuum System ◽  
Processing Temperature ◽  
Diffusion Couples ◽  
Electronic Circuits ◽  
Intermetallic Formation ◽  
Si Substrates ◽  
Aluminum Silicon

Thin films of aluminum or aluminum-silicon can be used in conjunction with thin films of chromium in integrated electronic circuits. For some applications, these films exhibit undesirable reactions; in particular, intermetallic formation below 500 C must be inhibited or prevented. The Al films, being the principal current carriers in interconnective metal applications, are usually much thicker than the Cr; so one might expect Al-rich intermetallics to form when the processing temperature goes out of control. Unfortunately, the JCPDS and the literature do not contain enough data on the Al-rich phases CrAl7 and Cr2Al11, and the determination of these data was a secondary aim of this work.To define a matrix of Cr-Al diffusion couples, Cr-Al films were deposited with two sets of variables: Al or Al-Si, and broken vacuum or single pumpdown. All films were deposited on 2-1/4-inch thermally oxidized Si substrates. A 500-Å layer of Cr was deposited at 120 Å/min on substrates at room temperature, in a vacuum system that had been pumped to 2 x 10-6 Torr. Then, with or without vacuum break, a 1000-Å layer of Al or Al-Si was deposited at 35 Å/s, with the substrates still at room temperature.

scholarly journals Roadmap of Terahertz Imaging 2021

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4092
Author(s):  
Gintaras Valušis ◽  
Alvydas Lisauskas ◽  
Hui Yuan ◽  
Wojciech Knap ◽  
Hartmut G. Roskos
Keyword(s):  
Room Temperature ◽  
Continuous Wave ◽  
Computational Imaging ◽  
Imaging Systems ◽  
Thz Imaging ◽  
Operational Conditions ◽  
Frequency Combs ◽  
Wave Imaging ◽  
On Chip ◽  
Nano Imaging

In this roadmap article, we have focused on the most recent advances in terahertz (THz) imaging with particular attention paid to the optimization and miniaturization of the THz imaging systems. Such systems entail enhanced functionality, reduced power consumption, and increased convenience, thus being geared toward the implementation of THz imaging systems in real operational conditions. The article will touch upon the advanced solid-state-based THz imaging systems, including room temperature THz sensors and arrays, as well as their on-chip integration with diffractive THz optical components. We will cover the current-state of compact room temperature THz emission sources, both optolectronic and electrically driven; particular emphasis is attributed to the beam-forming role in THz imaging, THz holography and spatial filtering, THz nano-imaging, and computational imaging. A number of advanced THz techniques, such as light-field THz imaging, homodyne spectroscopy, and phase sensitive spectrometry, THz modulated continuous wave imaging, room temperature THz frequency combs, and passive THz imaging, as well as the use of artificial intelligence in THz data processing and optics development, will be reviewed. This roadmap presents a structured snapshot of current advances in THz imaging as of 2021 and provides an opinion on contemporary scientific and technological challenges in this field, as well as extrapolations of possible further evolution in THz imaging.

Cryogenic Interlaminar Properties of PBO Fiber/Epoxy Composites

2011 ◽  
Vol 391-392 ◽  
pp. 1445-1449
Author(s):  
Chun Hua Zhang ◽  
Shi Lin Luan ◽  
Xiu Song Qian ◽  
Bao Hua Sun ◽  
Wen Sheng Zhang
Keyword(s):  
Liquid Nitrogen ◽  
Room Temperature ◽  
Liquid Nitrogen Temperature ◽  
Epoxy Composites ◽  
Bending Test ◽  
Test Results ◽  
Sem Images ◽  
Three Point Bending ◽  
Pbo Fiber ◽  
Interlaminar Shear

The influences of low temperature on the interlaminar properties for PBO fiber/epoxy composites have been studied at liquid nitrogen temperature (77 K) in terms of three point bending test. Results showed that the interlaminar shear strength at 77 K were significantly higher than those at room temperature (RT). For the analysis of the test results, the tensile behaviors of epoxy resin at both room temperature and liquid nitrogen temperature were investigated. The interface between fiber and matrix was observed using SEM images.

The Effect of Thermal Prestress on the Deformation of Micromirror Chip Embedded with Through-Silicon Vias

2011 ◽  
Vol 462-463 ◽  
pp. 563-568 ◽  
Author(s):  
Meng Kao Yeh ◽  
Chun Lin Lu
Keyword(s):  
Stress Distribution ◽  
Room Temperature ◽  
Thermal Loading ◽  
Heat Transfer Analysis ◽  
Processing Temperature ◽  
Temperature Decrease ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Through Silicon Vias ◽  
Silicon Vias

The thermal expansion mismatch problem for a chip due to temperature decrease from processing temperature to room temperature may cause residual stress inside the chip structure. The thermal prestress accumulated and may affect the chip reliability when the chip was subjected to the thermal loading again. In this paper, the effect of thermal prestress on the micromirror chip embedded with copper through-silicon vias (TSVs) was investigated by the finite element method. In analysis, the micromirror chip embedded with TSVs was analyzed first under thermal loading which resulted from temperature decrease between the stress free processing temperature and room temperature. This process produced a thermal prestress in the micromirror chip. The chip was then subjected to a heat source at the bottom while in operation and the heat transfer analysis was used to simulate this situation. Finally, the thermal stress analysis was carried out to obtain the deformation and the stress distribution in the chip. The results show that the thermal prestress had strong effect on the chip reliability and should be reduced as much as possible. This paper proposed a three steps analysis method to obtain the deformation and the stress distribution in the chip, in which the effect of thermal prestress on the chip reliability was evaluated effectively.

Effect of Reactant Preheating on the Stability of Non-Premixed Methane/Air Flames

2010 ◽  
Author(s):  
Sylvain Lamige ◽  
Ce´dric Galizzi ◽  
Jiesheng Min ◽  
Julien Perles ◽  
Fre´de´ric Andre´ ◽  
...  
Keyword(s):  
Room Temperature ◽  
Initial Temperature ◽  
Flame Stability ◽  
Air Velocity ◽  
Lifted Flames ◽  
Local Extinctions ◽  
Lift Off ◽  
Temperature Levels ◽  
The Stability ◽  
Jet Velocities

This study details the influence of reactant temperature on the stability of non-premixed CH4/air co-flow jet flames. Flame characteristics have been studied for five temperature levels (from 295 K to 600 K). The hysteresis zone formed by the limits between attached and lifted flame translates towards higher methane jet velocities with an increase of initial temperature, independently of the air velocity range. Moreover, critical velocities vary linearly with initial temperature. In addition, attachment and lift-off heights have been obtained from CH* chemiluminescence visualization. Results point out that the attachment height decreases significantly with temperature. Observations also indicate that the intrinsic process of lifting is modified. Pre-lifting anchored flame local extinctions, not observed at room-temperature, appear at higher initial temperatures; their occurrence increases with temperature. The lift-off height of turbulent lifted flames is also reduced with temperature. Overall, results show that increasing local temperature in the stabilization zone enhances flame stability.

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