Study of Mechanical Responses and Thermal Expansion of CNF-modified Polyester Nanocomposites Processed by Different Mixing Systems

2011 ◽  
Vol 1312 ◽  
Author(s):  
Muhammad E. Hossain ◽  
Mohammad K. Hossain ◽  
Mahesh Hosur ◽  
Shaik Jeelani
Keyword(s):  
Thermal Expansion ◽  
Mechanical Response ◽  
Carbon Nanofiber ◽  
Coefficient Of Thermal Expansion ◽  
Fracture Morphology ◽  
Mechanical Analysis ◽  
Mechanical And Thermal Properties ◽  
Compression Tests ◽  
Mechanical Mixing ◽  
Static Compression

ABSTRACTIn this study, different dispersion techniques such as sonication at high frequency, mechanical mixing, and magnetic stirring methods were employed to infuse 0.1 to 0.4 wt.% carbon nanofiber (CNF) into polyester matrix to study the influence of CNF on mechanical and thermal properties of the polyester nanocomposites. Dispersion of CNF studied using scanning electron microscopy (SEM) micrographs revealed excellent dispersion of CNF using sonication when 0.2 wt.% CNF was mixed in polyester resulting in enhanced mechanical response. On the other hand, agglomerations were observed in samples prepared with other mixing methods. Polyester with 0.2 wt.% CNF samples prepared by sonication resulted in 88% and 16% increase in flexural strength and modulus, respectively, over neat samples. Quasi-static compression tests showed similar increasing trend with addition of 0.2 wt.% CNF. Dynamic mechanical analysis (DMA) showed 35% and 5 °C improvement in the storage modulus and glass transition temperature (Tg), respectively, in the 0.2 wt.% loaded samples. Thermal mechanical analysis (TMA) performed on neat and samples with 0.2 wt.% CNF showed lower coefficient of thermal expansion (CTE) in nanophased sample compared to neat. Fracture morphology evaluated using SEM revealed relatively rougher surface in CNF-loaded polyester compared to neat as a result of better interaction between fiber and matrix due to the presence of CNF.

Effect of Dispersion Conditions on the Thermal and Mechanical Properties of Carbon Nanofiber–Polyester Nanocomposites

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
M. E. Hossain ◽  
M. K. Hossain ◽  
M. V. Hosur ◽  
S. Jeelani
Keyword(s):  
Carbon Nanofiber ◽  
Fracture Morphology ◽  
Xrd Analysis ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Compression Tests ◽  
Static Compression ◽  
Mechanical Responses ◽  
The Matrix ◽  
Dispersion Technique

In this study, sonication dispersion technique was employed to infuse 0.1–0.4 wt.% carbon nanofibers (CNFs) into polyester matrix to enhance thermomechanical properties of resulting nanocomposites. The effect of dispersion conditions has been investigated with regard to the CNF content and the sonication time. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) micrographs revealed excellent dispersion of 0.2 wt.% CNF infused in polyester, resulting in enhanced mechanical responses. Polyester with 0.2 wt.% CNF samples resulted in 88% and 16% increase in flexural strength and modulus, respectively, over the neat one. Quasi-static compression tests showed similar increasing trend with addition of CNF. Fracture morphology study of tested samples revealed relatively rougher surface in CNF-loaded polyester compared to the neat due to better interaction between the fiber and the matrix. Dynamic mechanical analysis (DMA) study exhibited about 35% increase in the storage modulus and about 5 °C increase in the glass transition temperature (Tg). A better thermal stability in the CNF-loaded polyester was observed from the thermogravimetric analysis (TGA) studies. Best results were obtained for the 0.2 wt.% CNF loading with 90 mins of sonication and 50% sonication amplitude. It is recommended that this level of sonication facilitates suitable dispersion of the CNF into polyester matrices without destroying the CNF's structure.

scholarly journals Tuning Thermal and Mechanical Properties of Polydimethylsiloxane with Carbon Fibers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1141
Author(s):  
Nevin Stephen Gupta ◽  
Kwan-Soo Lee ◽  
Andrea Labouriau
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Carbon Fibers ◽  
Coefficient Of Thermal Expansion ◽  
Mechanical And Thermal Properties ◽  
Mechanical Mixing ◽  
Scanning Calorimetry ◽  
Mechanical Hardness ◽  
Degradation Temperature ◽  
Cost Efficient

In order to meet the needs of constantly advancing technologies, fabricating materials with improved properties and predictable behavior has become vital. To that end, we have prepared polydimethylsiloxane (PDMS) polymer samples filled with carbon nanofibers (CFs) at 0, 0.5, 1.0, 2.0, and 4.0 CF loadings (w/w) to investigate and optimize the amount of filler needed for fabrication with improved mechanical properties. Samples were prepared using easy, cost-efficient mechanical mixing to combine the PDMS and CF filler and were then characterized by chemical (FTIR), mechanical (hardness and tension), and physical (swelling, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and coefficient of thermal expansion) analyses to determine the material properties. We found that hardness and thermal stability increased predictably, while the ultimate strength and toughness both decreased. Repeated tension caused the CF-filled PDMS samples to lose significant toughness with increasing CF loadings. The hardness and thermal degradation temperature with 4 wt.% CF loading in PDMS increased more than 40% and 25 °C, respectively, compared with the pristine PDMS sample. Additionally, dilatometer measurements showed a 20% decrease in the coefficient of thermal expansion (CTE) with a small amount of CF filler in PDMS. In this study, we were able to show the mechanical and thermal properties of PDMS can be tuned with good confidence using CFs.

Evaluation of CeSZ Thermal Barrier Coatings for Diesels

2000 ◽  
Author(s):  
P.J. Huang ◽  
J.J. Swab ◽  
P.J. Patel ◽  
W.S. Chu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Barrier Coatings ◽  
Coefficient Of Thermal Expansion ◽  
Fuel Efficiency ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Mechanical And Thermal Properties ◽  
Barrier Coatings ◽  
Spray Process

Abstract The development of thermal barrier coatings (TBCs) for diesel engines has been driven by the potential improvements in engine power and fuel efficiency that TBCs represent. TBCs have been employed for many years to reduce corrosion of valves and pistons because of their high temperature durability and thermal insulative properties. There are research programs to improve TBCs wear resistance to allow for its use in tribologically intensive areas of the engine. This paper will present results from tribological tests of ceria stabilized zirconia (CeSZ). The CeSZ was applied by atmospheric plasma spray process. Various mechanical and thermal properties were measured including wear, coefficient of thermal expansion, thermal conductivity, and microhardness. The results show the potential use of CeSZ in wear sensitive applications in diesel applications. Keywords: Thermal Barrier Coating, Diesel Engine, Wear, Thermal Conductivity, and Thermal Expansion

Mechanical and Thermal Properties of Carbon-Nanofiber Infused Polyurethane Foam

2008 ◽  
Author(s):  
Md. Atiqur Bhuiyan ◽  
Mahesh V. Hosur ◽  
Yaseen Farooq ◽  
Shaik Jeelani
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Polyurethane Foam ◽  
High Speed ◽  
Carbon Nanofiber ◽  
Mechanical Analysis ◽  
Mechanical And Thermal Properties ◽  
Diphenylmethane Diisocyanate ◽  
Thermal And Mechanical Properties ◽  
Mechanical Agitator

In this study, thermal and mechanical properties of carbon nanofiber infused polyurethane foam were investigated. Low density liquid polyurethane foam composed of Diphenylmethane Diisocyanate (Part A) and Polyol (Part B) was doped with carbon nanofibers (CNF). A high-intensity ultrasonic liquid processor was used to obtain a homogeneous mixture of Diphenylmethane Diisocyanate (Part A) and carbon nanofibers (CNF). The CNF were infused into the Part A of the polyurethane foam through sonic cavitation. The modified foams containing nanoparticles were mixed with Part B (Polyol) using a high-speed mechanical agitator. The mixture was then cast into pre-heated rectangular aluminum molds to form the nano-phased foam panels. Flexure, static and high strain rate compression, and dynamic mechanical analysis (DMA) were performed on neat, 0.2 wt%, 0.4 wt% and 0.6 wt% CNF filled polyurethane foam to identify the effect of adding CNF on the thermal and mechanical properties. The highest improvement on thermal and mechanical properties was obtained with 0.2 wt% loading of CNF. Morphology of the samples was studied through X-ray diffraction.

IMPROVEMENT OF MECHANICAL AND THERMAL PROPERTIES OF CFRP LAMINATES USING MICRO-FIBRILLATED CELLULOSE

2012 ◽  
Vol 06 ◽  
pp. 622-627 ◽  
Author(s):  
HYOJIN KIM ◽  
TADASHI SUZUKI ◽  
KENICHI TAKEMURA
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Thermal Properties ◽  
Carbon Fiber ◽  
Coefficient Of Thermal Expansion ◽  
Flexural Modulus ◽  
Mechanical And Thermal Properties ◽  
Flexural Test ◽  
Cfrp Laminates ◽  
Carbon Fiber Epoxy

The aim of this study is improvement of mechanical and thermal properties of plain woven carbon fiber (CF) reinforced epoxy with addition of MFC as the additive. Carbon fiber/epoxy laminates with addition 0.3, 0.5, 0.7 and 1wt% of MFC were characterized by flexural test, DSC and TMA. The result represented that the flexural strength improved slightly at 0.3 and 0.5 wt% of MFC, but flexural modulus was not changed, respectively. The glass transition temperature of MFC-CFRP laminates showed the increase according to increase of MFC addition at 0.7 and 1.0 wt%. The coefficient of thermal expansion was decrease by 0.7 wt% of MFC addition.

Nano-Engineering Silica Aerogel Structure to Determine the Property-Structure Relationship

2009 ◽  
Author(s):  
Gitogo Churu ◽  
Hongbing Lu ◽  
Nicholas Leventis
Keyword(s):  
Silica Aerogel ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Honeycomb Structure ◽  
Material Point ◽  
Compression Tests ◽  
Structure Directing Agent ◽  
Static Compression ◽  
Pluronic P123 ◽  
Structure Relationship

We characterize mechanically strong nano/meso-porous cross-linked templated silica aerogels that were synthesized through the sol gel process and reinforced by nano casting a 4–10nm thick conformal layer of isocynate derived polymer. Tri-block co-polymer (pluronic P123) was used as a structure directing agent to produce ordered mesoporous walls while 1, 3, 5 trimethylbenzene (TMB) was added as micelle-swelling reagent to regulate the size of the pores. The shape and size of the micro and meso pores were nano engineered by varying the amount of chemical surfactant as well as the concentration of the cross-linking solution used to form the polymer nano layer. In so doing we manipulated the structure at the molecular level to develop an optimized structure that closely resembles the honeycomb structure found in nature. Dynamic mechanical analysis (DMA) test results established that the material had an α-grass transition temperature of about 130°C while quasi-static compression tests showed that the optimized nano-structured silica aerogel had a Young’s modulus of about 800MPa. We present the synthesis protocol as well as chemical, physical and mechanical characterization of cross-linked templated silica aerogel (CTSA). ). In addition, material point method (MPM) simulation results are highlighted.

Mechanical and thermal properties of single crystals of ZrB2

2002 ◽  
Vol 753 ◽  
Author(s):  
N. L. Oka moto ◽  
M. Kusakari ◽  
K. Tanaka ◽  
H. Inui ◽  
M. Yamaguchi ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Thermal Expansion ◽  
Single Crystals ◽  
Elastic Constants ◽  
Layered Structure ◽  
Mechanical And Thermal Properties ◽  
Slip Systems ◽  
Compression Tests ◽  
Deformation Behaviors ◽  
Temperature Ranges

ABSTRACTCoefficients of thermal expansion (CTE), elastic constants and plastic deformation behaviors of single crystals of ZrB2, which possesses a hexagonal layered structure where pure Zr and pure B atomic planes stack alternatively along the c-axis, have been investigated in wide temperature ranges. While the observed elastic constants indicate highly anisotropic nature of atomic bonding being consistent with the layered structure, the observed CTE values are rather isotropic. Two operative slip systems, (0001)<1120> and on {1100}<1123>, are identified in compression tests. The observed plastic behaviors are discussed in the light of the deduced anisotropy in atomic bonding.

scholarly journals Mechanical and Thermal Properties of R-High Density Polyethylene Composites Reinforced with Wheat Straw Particleboard Dust and Basalt Fiber

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Min Yu ◽  
Haiyan Mao ◽  
Runzhou Huang ◽  
Zhenghao Ge ◽  
Pujian Tian ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Wheat Straw ◽  
High Density Polyethylene ◽  
Coefficient Of Thermal Expansion ◽  
Basalt Fiber ◽  
High Density ◽  
Mechanical And Thermal Properties ◽  
Linear Coefficient ◽  
Loading Level

The effect of individual and combined particleboard dust (PB dust) and basalt fibers (BFs) on mechanical and thermal expansion performance of the filled virgin and recycled high density polyethylene (HDPE) composites was studied. It was shown that the use of PB dust had a positive effect on improving mechanical properties and on reducing linear coefficient of thermal expansion (LCTE) values of filled composites, because the adhesive of the particle board held the wheat straw fibers into bundles, which made PB dust have a certain aspect ratio and high strength. Compared with the commonly used commercial WPC products, the flexural strength of PB dust/VHDPE, PB dust/RHDPE, and PB dust/VHDPE/RHDEPE at 40 wt% loading level increased by 79.9%, 41.5%, and 53.9%, respectively. When 40 wt% PB dust was added, the crystallization degree of the composites based on three matrixes decreased to 72.5%, 45.7%, and 64.1%, respectively. The use of PB dust can help lower the composite costs and increase its recyclability. Mechanical properties and LCTE values of composites with combined BF and PB dust fillers varied with PB dust and BF ratio at a given total filler loading level. As the BF portion of the PB dust/BF fillers increased, the LCTE values decreased markedly, which was suggested to be able to achieve a desirable dimensional stability for composites. The process provides a useful route to further recycling of agricultural wastes.

Influence of Chopped Fibre Length on the Mechanical and Thermal Properties of Silk Fibre-Reinforced Poly(Butylene Succinate) Biocomposites

2005 ◽  
Vol 13 (5) ◽  
pp. 479-488 ◽  
Author(s):  
Sang Muk Lee ◽  
Seong Ok Han ◽  
Donghwan Cho ◽  
Won Ho Park ◽  
Seung Goo Lee
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Coefficient Of Thermal Expansion ◽  
Fibre Length ◽  
Present System ◽  
Silk Fibre ◽  
Mechanical And Thermal Properties ◽  
Butylene Succinate ◽  
Linear Coefficient

The influence of chopped fibre length on the mechanical and thermal properties of silk fibre ( Bombix mori) reinforced poly(butylene succinate) (PBS) biocomposites has been investigated in terms of tensile and flexural properties, thermal stability, thermal expansion, and dynamic mechanical properties. The chopped fibre lengths studied were 3.2 mm, 6.4 mm, 12.7 mm, and 25.4 mm. The results demonstrate that chopped silk fibres play an effective role in improving the mechanical properties of PBS in the present system. At a fixed fibre loading of 40 wt%, the tensile strength and modulus of the PBS control were improved by 69% and 228%, respectively, in comparison with those of the biocomposite reinforced with 25.4 mm silk fibres. The flexural strength and modulus of PBS were also greatly improved by 167% and 323%, respectively. The thermal properties of PBS resin increased when incorporating chopped silk fibres in the composite matrix. The biocomposites had much lower linear coefficient of thermal expansion (CTE) values and higher storage moduli than the PBS controls above the glass transition region, especially with reinforcing silk fibres of 25.4 mm long.

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