• Journal of Welding and Joining
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• v.31 no.5
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• pp.77-81
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• 2013

We have investigated thermal stability of the mechanical and thermal conductive properties of Cu/STS/Cu 3 layered clad metal lead frame material for a LED device package at different temperatures ranging from RT to $200^{\circ}C$. The fabricated Cu/STS/Cu clad metal has a good thermal stability for the mechanical tensile strength and thermal conductivity of the over 50 $Kg/mm^2$ to the $150^{\circ}C$ and 270 $W/m{\cdot}K$ to the $200^{\circ}C$, respectively. This clad metal lead frame material at a high temperature of $150^{\circ}C$ shows a reinforced mechanical tensile strength by 1.5 times to conventional pure copper lead frame materials and also a comparable thermal conductivity to typical copper alloy lead frame materials.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.79-82
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• 2005

In this study, mechanical properties of carbon fabrics composite under the thermal shock cycling were evaluated. Due to the interactions between fiber and polymer matrix, it is reasonable to conclude that both thermal cycles of thermal shock result in improvement of interlaminar shear strength(ILSS) for the longer conditioning time duration. The rise in ILSS may be attributed to the improved adhesion by cryogenic compressive stress and also by the post-curing strengthening effect. However, the flexural and tensile strength were decreased with increasing conditioning time of thermal cycle.

• Advances in materials Research
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• v.11 no.3
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• pp.191-209
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• 2022

Very slow degradation of synthetic based polymers has created a severe environmental issue that increased awareness towards research in polymers of biodegradable property. Soy protein isolate (SPI) is a natural biopolymer used as matrix in green composites but it has limitations of low mechanical properties and high water sensitivity. To enhance mechanical properties and reduce water sensitivity of Jute-SPI composites, SPI was modified with pine rosin which is also a natural cross-linking agent. 30% glycerol on the weight basis of a matrix was used as a plasticizer. The fibre volume fraction was kept constant at 0.2 whereas the pine rosin in SPI ranged from 5% to 30% of the matrix. The effects of pine rosin on mechanical, thermal, water sensitivity and surface morphology have been characterized using various techniques. The mechanical properties and water absorbency were found to be optimum for 15% pine rosin in Jute-SPI composite. Therefore, Jute-SPI composite without pine rosin and with 15% pine rosin were chosen for investigation through characterization by Fourier transforms infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), X-Ray diffraction (XRD) and Scanning electron microscope (SEM). The surface morphology of the composite was influenced by pine rosin which is shown in the SEM image. TGA measurement showed that the thermal properties improved due to the addition of pine rosin. Antimicrobial test showed antimicrobial property in the composite occurring 15% pine rosin. The research paper concludes that the modification of SPI resin with an optimum percentage of pine rosin enhanced mechanical, thermal as well as water-resistant properties of jute fibre reinforced composites.

• Fibers and Polymers
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• v.6 no.2
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• pp.169-173
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• 2005

Low temperature plasma (LTP) treatment was applied to wool fabric with the use of a non-polymerizing gas, namely oxygen. After the LTP treatment, the fabric properties including low-stress mechanical properties, air permeability and thermal properties, were evaluated. The low-stress mechanical properties were evaluated by means of Kawabata Evaluation System Fabric (KES-F) revealing that the tensile, shearing, bending, compression and surface properties were altered after the LTP treatment. The changes in these properties are believed to be related closely to the inter-fiber and inter-yam frictional force induced by the LTP. The decrease in the air permeability of the LTP-treated wool fabric was found to be probably due to the plasma action effect on increasing in the fabric thickness and a change in fabric surface morphology. The change in the thermal properties of the LTP-treated wool fabric was in good agreement with the above findings and can be attributed to the amount of air trapped between the yams and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.176-181
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• 2008

This paper was studied the possibility on the recycling of the scrap used as the food packaging materials, PP/EVOH/PP multilayer. Recycling study was investigated into thermal and mechanical properties of samples which were mixed PP/EVOH waste plastics scrap with two kinds of compatibilizers. Melt behaviors as thermal property and tensile strength, % strain at break point, and tensile modulus as mechanical properties were investigated into kinds of and the weight ratio of compatibilizers. Mixed PP/EVOH waste plastics shows compatibity when Minanto-s and GMS as compatibilizers are mixed 0.5wt.% over.

• Fire Science and Engineering
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• v.27 no.3
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• pp.72-79
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• 2013

Recently, building constructions have been developed toward high-rise, long span, and multi-complexed using the high strength materials, optimized section. But the structural behavior of steel structural members built with a high strength steel at fire condition is not clarified because of lacking of information of related references such as mechanical and thermal properties at high temperature situation. In this paper, to evaluate the structural stability of member or frame of steel framed building at fire situation through the engineering method, the mechanical and thermal experimental coupon tests have conducted at various high temperatures and the comparison to those of ordinary strength steels were done.

• Carbon letters
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• v.15 no.1
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• pp.32-37
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• 2014

Multi-walled carbon nanotube (MWCNT)/epoxy composites are prepared by a vacuum assisted resin transfer molding (VARTM) method. The mechanical properties, fracture surface morphologies, and thermal stabilities of these nanocomposites are evaluated for epoxy resins with various amounts of MWCNTs. Composites consisting of different amounts of MWCNTs displayed an increase of the work of adhesion between the MWCNTs and the matrix, which improved both the tensile and impact strengths of the composites. The tensile and impact strengths of the MWCNT/epoxy composite improved by 59 and 562% with 0.3 phr of MWCNTs, respectively, compared to the epoxy composite without MWCNTs. Thermal stability of the 0.3 phr MWCNT/epoxy composite increased compared to other epoxy composites with MWCNTs. The enhancement of the mechanical and thermal properties of the MWCNT/epoxy nanocomposites is attributed to improved dispersibility and strong interfacial interaction between the MWCNTs and the epoxy in the composites prepared by VARTM.

• Advances in materials Research
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• v.4 no.2
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• pp.97-111
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• 2015

Polypropylene short fiber (PP)-clay particulate-epoxy ternary composites were prepared by reinforcing PP short fiber and clay particles in the range of 0.1 phr to 0.7 phr into epoxy resin. Prepared hybrid composites were characterized for their mechanical, thermal and flame retardant properties. The obtained results indicated an increase in impact resistance, tensile strength, flexural strength and Young's modulus to an extent (up to 0.5 phr clay and 0.5 phr PP short fiber) and then decreases as the reinforcing phases are further increased. The thermal stability of these materials are found to increase up to 0.2 phr clay and 0.2 phr PP addition, beyond which it is decreased. Addition of clay is found to have the negative effect on epoxy-PP short fiber composites, which is evident from the comparison of mechanical and thermal properties of epoxy-0.5 phr PP short fiber composite and epoxy-0.5 phr PP short fiber-0.5 phr clay composite hybrid. UL-94 tests conducted on the composite hybrids have showed a reduction in the burning rate. Morphological observations indicated a greater fiber pull with the addition of clay. The performed tests in the present study indicated that materials under investigation have promising applications in construction, agriculture and decorative purposes.

• Textile Coloration and Finishing
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• v.33 no.3
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• pp.131-140
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• 2021

Collagen and chitosan are used in medical and cosmetic materials as natural polymers. In order to utilize the advantages of the materials, collagen/chitosan conjugated wet-spun fibers were prepared. The analysis of surface, optical, thermal and mechanical properties was carried out on the various composition of collagen and chitosan. As a result of images analysis, it was verified that the collagen/chitosan conjugated fibers were stably spun. In addition, the optical and thermal properties of fibers were observed to be changed by hydrogen bond. As a result, an optimized composition could be found at an appropriate content. Moreover, the optimized fibers have mechanical properties similar to chitosan fibers, while improving the structural and thermal stability by its hydrogen bond. In addition, the wet-spun collagen/chitosan conjugated fibers can be applied to medical and various fields through mechanical properties according to content control.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.3
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• pp.199-205
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• 2015

The mechanical and thermal properties of high temperature aluminate cementitious thermal storage materials were investigated in this paper. Alumina cement was used as basic binder and the effect of the replacement of fly ash, silica fume, calcium sulfo-aluminate and graphite for alumina cement was investigated. Experiments were performed to measure mechanical properties including compressive strength before and after thermal cycling, and split tensile strength, and to measure thermal properties including thermal conductivity and specific heat. Test results show that the residual compressive strengths of mixtures with alumina cement only, or alumina cement and silica fume were greater than those of the others. Additionally, the specific heat of mixture with graphite was largest in all the mixtures used in the study. The results of this study could be used to provide realistic information for material properties in thermal energy storage concrete in the future.