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.

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.

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.

Improving mechanical and thermal properties of graphite–aluminium composite using Si, SiC and eggshell particles

2019 ◽  
Vol 54 (17) ◽  
pp. 2365-2376 ◽  
Author(s):  
MO Durowoju ◽  
TB Asafa ◽  
ER Sadiku ◽  
S Diouf ◽  
MB Shongwe ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Relative Density ◽  
Coefficient Of Thermal Expansion ◽  
Mechanical And Thermal Properties ◽  
Sem Images ◽  
Plasma Sintering ◽  
Low Thermal Expansion ◽  
Spark Plasma

Graphite–aluminium (Gr–Al) composites are being used for diverse engineering applications because of their light weight, good electrical conductivity and thermal properties. However, their applications are limited by high coefficient of thermal expansion and low microhardness values which can be enhanced by adding cheap and efficient fillers. This paper reports the effect of addition of eggshell (ES) particles on the properties of sintered Gr–Al-based composites. Five different composites (Gr–Al, Gr–Al  +  20 wt.%Si, Gr–Al + 20 wt.%SiC, Gr–Al + 20Si wt.% + 20 wt.%ES and Gr–Al + 20SiC wt.% + 20 wt.%ES) were sintered at a temperature of 540 ℃, holding time of 10 min, heating rate of 52 ℃/min and pressure of 50 MPa using spark plasma sintering system. The sintered samples were characterized based on morphology, microhardness, relative density, coefficient of thermal expansion and electrical conductivity. Based on SEM images, graphite particles of flake-like structure were largely undeformed while Al particles were smaller, round and irregular in shape and fairly uniformly distributed in the composites. The microhardness value of sintered Gr–Al + 20 wt.%SiC + 20 wt.%ES composite was 39.55 HV compared to 30.46 HV for Gr–Al, the least of the samples. The Gr–Al + 20 wt.%SiC + 20 wt.%ES composite also has a very low thermal expansion coefficient (0.98 × 10−5/K) but lowest electrical conductivity at temperature beyond 150 ℃. Highest densification and minimum relative density (94%) were obtained in Gr–Al + 20 wt.%Si + 20 wt.%ES composite. These enhanced performances are largely due to the incorporation of ES particles. This study therefore demonstrated that ESs particles enhanced microhardness and lowered thermal expansion of Gr–Al-based composites which have promising applications in industries especially for thermal management.

scholarly journals A Study on the Dynamic Mechanical Properties of Silk Fibre Composites

2011 ◽  
Vol 410 ◽  
pp. 106-109
Author(s):  
Mei Po Ho ◽  
Hao Wang ◽  
Chun Kit Ho ◽  
Kin Tak Lau
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Medical Engineering ◽  
Dynamic Mechanical Properties ◽  
Silk Fibre ◽  
Mechanical And Thermal Properties ◽  
Bone Implant ◽  
Dynamic Mechanical ◽  
Fibre Composites ◽  
Biodegradable Properties

Silk fibre has been popularly used for bio-medical engineering and surgically-operational applications because of its biocompatible and bio-resorbable properties for centuries. Using silk fibre as reinforcement for some bio-polymers to enhance the stiffness of scaffolding and bone implant plates has been developed. However, its dynamic mechanical properties with the biodegradable properties have not yet well understood. In this paper, the dynamic mechanical and thermal properties of degraded and non-degraded silk fibre reinforced Polylactic acid (PLA) composites are discussed.

scholarly journals Improvement in Mechanical and Thermal Properties of Graphite Flake/Cu Composites by Introducing TiC Coating on Graphite Flake Surface

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 519 ◽  
Author(s):  
Ren Zhang ◽  
Xinbo He ◽  
Qian Liu ◽  
Xuanhui Qu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Hot Pressing ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Packaging Material ◽  
Graphite Flake ◽  
Mechanical And Thermal Properties ◽  
Electronic Packaging Material

In this work, TiC coating was successfully deposited on a graphite flake surface via molten salt technique, for the purpose of promoting the interfacial connection between Cu and graphite flake. Vacuum hot pressing was then employed to prepare TiC-coated graphite flake/Cu composite. The results indicate that introducing TiC coating on graphite flake surface can evidently reduce the pores and gaps at the interface, resulting in a significant improvement on the bending strength. When the TiC-coated graphite flake content is 60 vol%, the bending strength is increased by 58% compared with the uncoated one. The coefficient of thermal expansion dropped from 6.0 ppm·K−1 to 4.4 ppm·K−1, with the corresponding thermal conductivity as high as 571 W·m−1·K−1. The outstanding thermal conductivity, apposite coefficient of thermal expansion, as well as superior processability, make TiC-coated graphite flake/Cu composite a satisfactory electronic packaging material with vast prospect utilized in microelectronic industry.

scholarly journals Synchronously Improved Voltage Gradient and Mechanical Properties of ZnO Based Varistor by Doping Ga2O3

2020 ◽  
Author(s):  
Bo-wen Wang ◽  
Bao-hui Chen ◽  
Peng-zhao Gao ◽  
Hui-hui Chen ◽  
Pei Zhang
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Grain Boundary ◽  
Substitutional Solid Solution ◽  
Voltage Gradient ◽  
Mechanical And Thermal Properties ◽  
Abnormal Growth ◽  
Zno Crystal

Abstract ZnO based varistors with high voltage gradient and excellent mechanical and thermal properties were fabricated by Ga2O3 doping and using nanoparticles. The compositions and microstructure of the varistors, as well as their electrical, mechanical and thermal properties were investigated by XRD, XPS, SEM, E-J, C-V, mechanical and thermal expansion measurements. Also, the mechanism of Ga2O3 addition on electrical and mechanical properties of the varistors was discussed detailedly. Results showed that the added Ga2O3 preferentially occupied the lattice position of ZnO crystal through the formation of a substitutional solid solution (Donor doping), they then occupied the void position through the formation of an interstitial solid solution (Acceptor doping), in which residual Ga2O3 existed in the grain boundary and served as inversion boundaries. The formation of the substitutional and interstitial solid solutions helped to improve the electrical properties, when the Ga2O3 content was 0.40 mol%, E1mA, α and K were 1235.00 V·mm− 1, 46.0 and 1.37, respectively, being due to the small particle size and the relative content of donor, acceptor and grain boundary in ZnO grain; The increased content of inversion boundaries stimulated the abnormal growth of ZnO grain, and the formed plate-like grain helped to improve the mechanical properties and thermal expansion coefficient of the varistors, values of σf, Ef, and KIC reached 147.43 MPa, 213.61 GPa and 2.05 MPa·m1/2, showing improvements of 25.29%, 47.67%, and 38.51%, respectively, compared with those of ZnO varistors without Ga2O3.

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.

Mechanical and thermal properties of combustion-synthesized perovskites, La1−xSrxCr0.2Fe0.8O3

2001 ◽  
Vol 16 (12) ◽  
pp. 3545-3553 ◽  
Author(s):  
Yeong-Shyung Chou ◽  
K. Kerstetter ◽  
L. R. Pederson ◽  
R. E. Williford
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Mechanical And Thermal Properties ◽  
Flexure Strength ◽  
Linear Coefficient ◽  
Shear Moduli ◽  
Critical Flaw ◽  
Microhardness Indentation ◽  
Biaxial Flexure

This paper examined the room-temperature thermal and mechanical properties of a mixed conducting perovskite La1−xSrxCr0.2Fe0.8O3 (x = 0.2 to 0.8). Powders were made by the combustion-synthesis technique and sintered at 1250 °C in air. Sintered density, crystal phase, and grain size were characterized. Linear thermal expansion in air was also tested. Young's and shear moduli, microhardness, indentation fracture toughness, and biaxial flexure strength were determined. It was found that the linear coefficient of thermal expansion increased with increasing Sr content, while elastic modulus appeared to decrease with increasing Sr content. Young's modulus of 128 to 192 GPa and shear modulus of 51 to 74 GPa were measured. A biaxial flexure strength of 243 MPa was measured for the lowest Sr content batches. Batches with higher Sr concentrations (x = 0.6 to 0.8) showed extensive cracking. Indentation toughness showed a decrease with increasing Sr content. In addition, fractography was used to characterize the critical flaw and the fracture mode.

scholarly journals Development of PE/PCL Bilayer Films Modified with Casein and Aluminum Oxide

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3090
Author(s):  
Anita Ptiček Siročić ◽  
Ana Rešček ◽  
Zvonimir Katančić ◽  
Zlata Hrnjak-Murgić
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Water Vapor ◽  
Aluminum Oxide ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Mechanical And Thermal Properties ◽  
Oxide Compound ◽  
Bilayer Films ◽  
Oxide Particles

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al2O3 showed the lowest WVTR value.

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

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