• Elastomers and Composites
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• 제38권2호
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• pp.167-174
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• 2003

Thermoplastic vulcanizates (TPV) or dynamic vulcanizates are thermoplastic elastomers produced by simultaneous mixing and crosslinking of a rubber and a thermoplastic. The objective of the present work is to investigate the effects of different types of peroxides as curing agents on the properties of PP/EPDM TPVs. The mechanical properties change significantly with the chemical nature of the peroxides and the extent of crosslinking at a fixed PP/EPDM blend ratio. The tensile strength of the TPVs obtained with the various peroxides can be related to the solubility parameters of the polymers and of the peroxides. The Young's modulus of the peroxide-cured TPVs can be correlated with the delta torque values of equivalent thermoset EPDM vulcanizates, corresponding to the crosslinking efficiencies of the peroxides.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.198-201
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• 2004

This paper aims to investigate the micro-mechanical behaviour of tow geometry with forming pressures and densities of foams during the curing process of plain weave carbon fibre fabric prepregs onto polymer foams. In order to find out and compare deformation patterns between different forming conditions, tow parameters such as amplitude and crimp angle etc. are investigated. From the observation results, geometric difference in the tow architecture with respect to forming conditions and foam characteristics were found. To observe the micro-deformation of the fabric structure, appropriate specimens from carbon fibre-foam sandwich structures are sectioned and observed under the microscope.

• 한국인쇄학회지
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• 제18권2호
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• pp.113-124
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• 2000

It is well known that the characteristics of liquid crystal polymer composite(LCPC) films are possessed of large-area and flexible display, polarizer free, high contrast, wide angle of visual filed and high responsiveness. In this study, we have investigated to the best optimal mixing rates chiral nematic liquid crystals and UV-curable resins having different properties acrylate moleculars. The purpose of this study has been the development of new functional application with liquid crystal polymer composite films. For example the films were applied a new thermal sensor. In results, best phase separation behaviors turned out liquid crystal/monomer/oilgomer mixture system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.207-208
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• 2007

Recently, high performance microelectronic devices are designed in multi-layer structure in order to make dense wiring of metal conductors in compact size. Imprint lithography have received significant attention due to an alternative technology for photolithography on such devices. In this work, we synthesized dielectric composite materials based on epoxy resin, and investigated their thermal stabilities and dynamic mechanical properties for thermal imprint lithography. In order to enhance the mechanical properties and toughness of dielectric material, various modified polyetherimide(PEI) was applied in the resin system. Curing behaviours, thermal stabilities, and dynamic mechanical properties of the dielectric materials cured with various conditions were studied using dynamic differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), and Universal Test Method (INSTRON).

• 한국재료학회지
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• 제15권1호
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• pp.1-5
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• 2005

Copper-based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or black-oxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. Fracture surfaces were analyzed by various equipment to investigate failure path. The present paper deals with the failure path, and the cause of the failure path formation with an adhesion model will be treated in the succeeding paper.

• 한국재료학회지
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• 제15권1호
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• pp.6-13
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• 2005

Copper based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or blackoxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. After fracture toughness testing, the fracture surface were analyzed by various equipment to investigate failure path. An adhesion model was suggested to explain the failure path formation. The adhesion model is based on the strengthening mechanism of fiber-reinforced composite. The present paper deals with the introduction of the adhesion model. The explanation of the failure path with the proposed adhesion model was introduced in the companion paper.

• Elastomers and Composites
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• 제26권1호
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• pp.15-22
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• 1991

Blends of ethylene-propylene-diene terpolymer(EPDM) and high density polyethylene(HDPE) have been prepared in a roll mill by the process "dynamic curing" where both blending and a crosslinking reaction was carried out simultaneously. As a crosslinking agent, dicumyl peroxide(DCP) was used. Throughout the experimental ranges, the dynamically cured polyblends were shown to be thermoplastic elastomers except highly crosslinked blends of high compositions of EPDM. The increase of melt viscosity was observed as EPDM composition and DCP contents increased. From DSC determinations, the crystallinity decreased with increasing contents of DCP. The tensile strength and elongation at break generally increased with increasing DCP content and increasing HDPE compositions, but highly depended on the combined effects of decreasing crystallinity and increasing crosslinking density.

• 콘크리트학회논문집
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• 제18권1호
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• pp.117-124
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• 2006

본 연구에서는 복합 재질 폐플라스틱(PA)을 이용한 폴리머콘크리트의 작업성, 경화시간 및 경화수축에 미치는 결합재 첨가량 및 PA 혼입량의 영향에 대하여 검토하였다. 그 결과 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 작업성은 결합재 첨가량, PA 혼입량 및 필러 혼입량의 증가에 따라 증가하는 경향을 나타냈다. 복합 재질 폐플라스틱을 이용한 폴리머콘크리트의 경화시간은 촉매제 첨가량 및 양생온도의 증가에 따라 짧아지는 경향을 나타냈다. 복합 재질 폐플라스틱을 이용한 폴리머콘크리트의 길이변화는 결합재 첨가량 및 PA 혼입량의 증가에 따라 증가하는 경향을 보였다. 본 연구 결과가 복합 재질 폐플라스틱 종말품의 재활용에 조금이나마 기여할 수 있을 것을 기대하며 향후 지속적인 연구개발을 통하여 더욱 광범위한 복합재질 폐플라스틱 종말품의 재활용이 이루어질 수 있을 것으로 판단된다.

• 폴리머
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• 제31권6호
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• pp.474-478
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• 2007

다이사이클로펜타다이에닐 비스페놀 시아네이트 에스터 올리고머와 열가소성 수지인 폴리페닐렌에테르(PFE)를 복합체화함으로써 유전손실이 적은 고분자 기판소재를 제작하였다. 올리고머와 촉매의 경화반응을 분석하여 최적 촉매첨가량을 Zn 0.02 phr로 선정하고 이를 복합체 제작에 적용하였다. 올리고머와 PPE의 함량비를 변화시키며 제작된 복합체의 동박 박리 강도, gel content 등을 측정하였으며, GHz 대역에서의 유전율과 유전손실을 평가하였다. PPE의 함량은 박리 강도 및 유전특성에 큰 영향을 주었으나, 촉매의 함량에 따라서는 유전특성에 큰 차이가 없었다. 실험결과 박리 강도가 1 kN/m 이상이고, 1 GHz에서 유전손실이 0.004로 낮은 고분자 복합체 라미네이트를 얻을 수 있었다.

• 폴리머
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• 제38권2호
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• pp.171-179
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• 2014

우수한 성능을 지닌 대형 구조의 섬유강화 고분자(FRP) 복합재료 제품을 제조하기 위해 저온 경화형 프리프레그 개발이 활발히 진행되고 있다. 본 연구에서는 저온 경화형 프리프레그 제조에 적합한 매트릭스 수지를 확보하기 위하여 에폭시 수지, 경화제, 경화 촉진제로 구성된 저온 경화형 에폭시 수지 조성물의 경화거동 및 화학유변학을 고찰하였다. 경화반응 특성은 시차주사열량분석법과 유변물성측정법을 활용하여 승온 및 등온 조건에서 분석하였다. 연구 결과 매트릭스 수지로 제안된 저온 경화형 에폭시 수지 조성물은 $80^{\circ}C$에서 3시간에 경화시킬 수 있었고, 80과 $90^{\circ}C$에서의 젤화 시간은 각각 120분과 20분인 것으로 나타났다. 저온 경화형 수지를 경화시킨 수지 경화물의 열적, 기계적 물성은 고온 경화형 수지 경화물의 물성과 거의 동등하였다.