탄소섬유 직물 및 전도성 탄소 필러가 고충진 된 열가소성 탄소섬유강화플라스틱의 전도 특성

김성륜 ( Seong Yun Kim ),노예지 ( Ye Ji Noh ),장지운 ( Ji-un Jang ),최성규 ( Seong Kyu Choi ) 한국복합재료학회 2021 Composites research Vol.34 No.5

지구 온난화 억제를 위한 전 세계적인 연비규제에 발맞춘 해결책으로 자동차에 경량구조복합재료를 적용하는 것이 메가트렌드로 인식되고 있다. 본 연구에서는 수리, 폐기 및 재활용 측면에서 유리한 열가소성 탄소섬유강화플라스틱의 적용을 극대화하기 위해 전도특성이 요구되는 부품 대체 이슈에 대응할 수 있는 기술적 접근을 제공하는 것을 목표로 수행되었다. 저점도 중합 가능한 기지재의 특성을 활용하여 전도성 필러를 파우더 믹싱 방법으로 균일하게 혼입하면서도 우수한 함침 특성을 나타내는 열가소성 탄소섬유강화플라스틱 제조방법에 기초하여 카본블랙, 탄소나노튜브, 그래핀 나노플레이틀렛, 흑연, 피치계 탄소섬유 등 다양한 탄소기반 전도성 필러를 최대 함량까지 혼입하여 전기저항 및 열전도도를 비교하여 고찰하였다. 전도성 탄소 필러의 종류나 형태보다는 최대 혼입량이 시편의 전도 특성을 제어하기 위해 가장 중요한 인자임을 확인하였고, 전기전도 특성을 향상시키기 위해서는 1차원 형태의 전도성 탄소필러를 적용하는 것이 유리할 수 있는 반면 열전도 특성을 향상시키기 위해서는 2차원 형태의 전도성 탄소필러를 적용하는 것이 유리 할 수 있다는 실험 결과를 확인하였다. 본 연구의 결과들은 열가소성 탄소섬유강화플라스틱의 전도 특성을 제어하기 위한 최적 구조 설계에 잠재적인 통찰력을 제공할 수 있다. The application of lightweight structural composites to automobiles as a solution in line with global fuel economy regulations to curb global warming is recognized as a megatrend. This study was conducted to provide a technical approach that can respond to the issue of replacing parts that require conductive properties to maximize the application of thermoplastic carbon fiber reinforced plastics (CFRPs), which are advantageous in terms of repair, disposal and recycling. By utilizing the properties of the low-viscosity polymerizable oligomer matrix, it was possible to prepare a thermoplastic CFRP exhibiting excellent impregnation properties while uniformly mixing the conductive filler. Various carbon-based conductive fillers such as carbon black, carbon nanotubes, graphene nanoplatelets, graphite, and pitch-based carbon fibers were filled up to the maximum content, and electrical and thermal conductive properties of the fabricated composites were compared and studied. It was confirmed that the maximum incorporation of filler was the most important factor to control the conductive properties of the composites rather than the type or shape of the conductive carbon filler. Experimental results were observed in which it might be advantageous to apply a one-dimensional conductive carbon filler to improve electrical conductivity, whereas it might be advantageous to apply a two-dimensional conductive carbon filler to improve thermal conductivity. The results of this study can provide potential insight into the optimization of structural design for controlling the conductive properties of thermoplastic CFRPs.

전기자동차 배터리 하우징용 열전도성 고분자 복합재료

윤여성,장민혁,문동준,장은진,오미혜,박주일 한국융합학회 2022 한국융합학회논문지 Vol.13 No.4

전기자동차용 배터리 하우징 소재로 사용되고 있는 금속 소재에서 경량소재로 대체하기 위한 열가소성복합 재료를 제조하였다. 매트릭스 소재는 고분자 소재인 나일론 6를 사용 하였으며 방열 성능을 부여하기 위해 열전도 도가 높은 Boron Nitrate(BN)를 사용하였다. 동일한 필러의 함량 및 입자 크기에 따른 열전도성 고분자 복합재료의 방열 특성을 분석하였다. 필러의 함량이 증가할수록 열전도도 값이 증가하였으며, 입자크기가 60∼70㎛인 BN의 함량이 50%인 복합재료의 경우 1.4W/mK 이상 열전도도를 나타내었다. 입자 크기가 클수록 입자 간 계면 접촉면이 넓어져 Thermal path가 이루어짐을 확인하였다. 제조된 열전도성 고분자복합재료를 이용하여 배터리 하우징을 제작하였으며 셀의 충방전 동안 온도 변화를 관찰하여 배터리 하우징의 대체 소재로서의 가능성을 확인하였다. Manufactured thermoplastic composite materials to replace the metal materials used as battery housing materials for electric vehicles with lightweight materials. As the matrix material, nylon 6 which is a polymer material was used. Boron Nitrate(BN), which has high thermal conductivity, was used to provide heat dissipation performance. The heat dissipation characteristics of the thermally conductive polymer composite material according to the BN content and particle size were analyzed. The thermal conductivity value increased as the filler content increased, and composite materials particle size of 60 to 70㎛ and BN content of 50%, the thermal conductivity was 1.4 W/mK. The larger the particle size, the wider the inter-particle interface contact surface, which means that a thermal path was formed. wider the interfacial contact surface between the particles, and the thermal path was formed. A battery housing was manufactured using the manufactured thermally conductive polymer composite material, and the temperature change during charging and discharging of the cell was observed, and the possibility as a substitute material for the battery housing was confirmed.)

고주파 유도결합 열플라즈마를 이용한 IT-SOFC용 LSCF 나노분말 합성 및 전기전도도 특성 평가

이호상,정상민,양시영,서준호 한국수소및신에너지학회 2021 한국수소 및 신에너지학회논문집 Vol.32 No.2

This work investigates the characteristics of LSCF nano-powders prepared by RF thermal plasma method and the electrical conductivity of their sintered body. XRD graphs and FE-SEM images of the as-synthesized powders showed that single phase LSCF nano- particles were synthesized with the averaged sizes of ≤300 nm. TEM mapping images and ICP-MS data revealed that metal atoms, La, Sr, Co, Fe, were incorporated into a single particle with small difference of <3 wt% in global composition. In addition, the as-synthesized powders were pressed in the shape of disk and sintered at 1,100℃ for 3 hours. For the sintered body, electrical conductivities were measured for temperatures between 20℃ to 750℃ by using Van der Pauw method, showing high electrical conductivity of ≥300 S/cm at 750℃.

탄소섬유강화 복합소재의 열적, 전기적, 기계적 특성에 대한 질화붕소 첨가제의 효과

홍현기,배곽진,유재상 한국복합재료학회 2020 Composites research Vol.33 No.3

In this paper, hexagonal boron nitride (h-BN) particles were added between the sheets of prepreg, and the effect of on many properties of BN-embedded carbon fiber reinforced plastics was investigated. The amount of BN particles which corresponds with 0 to 15 wt% of total resin weight was used as an additive material. The tensile strength and the inter-laminar shear strength of BN-embedded CFRP samples were improved by maximally 13.6%, and 6.7%, respectively. The tendency changes of thermal, electrical conductivities and the morphology of cross-section of CFRPs were also observed. This study suggests the possibility of controlling the characteristics of carbon fiber-BNepoxy composites to use for aerospace applications. 질화붕소(BN)는 높은 열전도도를 가지는 2D 형상의 부도체로 복합재료의 강화 필러로 연구되고 있는 물질이다. 본 연구에서는 판상의 육방정 질화붕소(h-BN)를 탄소섬유 다발 사이에 첨가하여 BN이 함유된 탄소섬유강화 복합소재(CFRPs)를 제조하여 BN 필러가 CFRP의 여러 물성에 어떤 영향을 주는지 탐구하였다. 사용된 프리프레그의 수지 총량의 0-15 wt%의 BN 필러가 프리프레그 층 사이에 첨가되었다. BN 필러가 첨가된 복합소재의인장강도는 최대 13.6%, 계면간 전단응력은 최대 6.7% 증가하는 것을 관찰하였다. BN 첨가량에 따른 열전도도와전기전도도의 변화와, BN의 첨가량에 따른 시편의 단면 형상 변화 또한 관찰되어 탄소섬유-BN-에폭시 복합소재의 물성 제어 가능성을 제시하였다.

CNT-Polyamide 복합재의 전기/열 전도도 및 인장강도변화에 관한 연구

김경재,박영수,송준혁,강신재,양성모 한국기계기술학회 2016 한국기계기술학회지 Vol.18 No.2

The effect of CNT diameters on properties of CNT-polyamide composites was investigated such as electrical conductivity, tensile strength and thermal conductivity. To get different diameter distributions of CNTs, several portions of Mo and Fe in Mo-Fe/MgO catalysts were synthesized by a combustion method at 600℃. And all CNTs growed at 900℃ with 3 SLM methane and 1 SLM hydrogen for 40min. Four kinds of CNTs with different diameter distributions, such as 1~3nm, 3~7nm, 7~13nm, and 10~30nm, were selected to make CNT-polyamide composites. Each composite was manufactured by a solution mixing using bar-type ultra-sonicator in the CNT portions from 1phr to 50 phr. And electrical conductivity, tensile strength, and thermal conductivity were measured. Three properties of CNT-polyamide composite, manufactured with 10nm diameter, were more excellent compared to other composites, with electrical conductivity 10 Ω at 7phr, thermal conductivity 2.4.W/mK at 40phr, tensile strength 60MPa at 30phr. CNTs with a diameter of 10nm were superior to other diameters for the multi-functional composite such as CNT-polyamide composites.

폴리페닐렌설파이드(PPS) 복합소재 제조 및 응용

최민식,이정록,류성우,구본철 한국복합재료학회 2020 Composites research Vol.33 No.3

Polyphenylene sulfide (PPS) is a semi-crystalline engineering thermoplastic resin that has outstanding thermal stability, mechanical strength, inherent flame retardancy, chemical resistance, and electrical properties. Due to these outstanding properties, it is preferred as a matrix for composite materials. Many studies have been conducted to produce composites with carbon fibers and glass fibers to improve mechanical properties and provide functionality of PPS. In this review paper, we report a brief introduction to the fabrication and applications of PPS composites with carbon nanotubes, graphene, carbon fibers, and glass fibers. 폴리페닐렌설파이드(PPS)는 반결정성 엔지니어링 열가소성 수지로 뛰어난 열안정성, 우수한 기계적 강도, 고유의 난연성 및 내화학성, 전기적 특성을 갖고 있다. 이러한 우수한 특성으로 인해 PPS는 복합체의 매트릭스로 선호되고 있다. PPS의 기계적 물성을 향상시키며 기능성 부여를 위해 탄소섬유나 유리섬유와 같은 필러를 이용 한 복합화 연구가 진행되어 오고 있다. 본 총설 논문에서는 PPS와 탄소나노튜브, 그래핀, 탄소섬유, 유리섬유 등 과의 복합체 제조 및 응용에 대한 연구를 소개하고자 한다.

Reduced Graphene Oxide 첨가를 통한 Polyvinyl Alcohol의 전기전도도, 열전도율의 향상 및 EMI Shielding에 적용

김재훈(Jae Hun Kim),박영철(Yeong Cheol Park),설재훈(Jae Hun Seol) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

Recently, polymeric materials have been used for the studies on electromagnetic interference (EMI) shielding in order to induce the absorption mechanism rather than reflection mechanism by metallic sheets. However, the low thermal conductivity of a polymer, which generally ranges in 0.1 to 0.4 W/mK, has been an unsolved problem for this application. Adding nanoparticles with high thermal conductivity leads to overcoming this drawback. The electrical conductivity of the nanocomposite also improves by adding nanoparticles along with the increase in the thermal conductivity. In this research, we measured the sheet resistance of a polyvinyl alcohol (PVA)/reduced graphene oxide (rGO) film and also the thermal conductivity of the film using a suspended microdevice.

저전력 및 고효율 면상발열체를 위한 피치기반 탄소종이 제조 및 특성

양재연,윤동호,김병석,서민강 한국복합재료학회 2018 Composites research Vol.31 No.6

In this work, phenolic resins containing conductive carbon fillers, such as, petroleum coke, carbon black, and graphite, were used to improve the surface heating elements by impregnating a pitch-based carbon paper. The influence of conductive carbon fillers on physicochemical properties of the carbon paper was investigated through electrical resistance measurement and thermal analysis. As a result, the surface resistance and interfacial contact resistivity of the carbon paper were decreased linearly by impregnating the carbon fillers with phenol resins. The increase of carbon filler contents led to the improvement of electrical and thermal conductivity of the carbon paper. Also, the heating characteristics of the surface heating element were examined through the applied voltage of 1~5 V. With the applied voltage, it was confirmed that the surface heating element exhibited a maximum heating characteristic of about 125.01oC(5 V). These results were attributed to the formation of electrical networks by filled micropore between the carbon fibers, which led to the improvement of electrical and thermal properties of the carbon paper. 본 연구에서는 면상발열체 특성을 향상시키기 위해 피치계 탄소종이에 전도성 탄소필러로 석유계 코크스, 카본블랙, 흑연을 페놀수지와 함께 함침시켰으며, 탄소종이에 함침된 탄소필러가 물리화학적 성질에 미치는영향을 전기적, 열적 특성 분석을 통해 고찰하였다. 그 결과, 면저항과 계면접촉저항이 선형적으로 감소하였으며, 탄소필러의 함량이 증가함으로써 전기전도도와 열전도도가 향상하였다. 또한, 탄소종이에 1~5 V 전압을 인가하였을 경우 탄소종이의 면상발열 특성을 관찰하였을 때 5 V 전압에서 최대 125.01oC로 발열 특성을 나타내었다. 이러한 결과는 탄소섬유 사이에 존재하는 미세공극이 채워짐으로써, 전기적 네트워크가 형성되어 전기적 및 열적특성이 향상되었기 때문이다.

우주용 경량 전자장비 구조체 국내 연구 동향

장태성(Jang, Tae Seong),이주훈(Rhee, Juhun) 한국항공우주연구원 2018 항공우주산업기술동향 Vol.16 No.2

본 논문은 위성에 장착되는 전자장비 구조체를 종래의 알루미늄 합금에서 복합재료로 대체함으로써 위성의 경량화를 극대화할 수 있는 대안을 다루었다. 이를 위해, 강성, 열전도도, 방사차폐, EMI차폐 및 전기전도도의 요구조건을 정의하였으며, 알루미늄 합금을 복합재료로 대체하기 위하여, 국내에서 수행되어 기 발표 및 게재 되었던 모듈화 형태의 경량 복합재료 전자장비 구조체의 개념설계와 모듈화 형태 구조체의 복잡한 제작 공정을 보완한 일체형 경량 복합재료 전자장비 구조체의 설계, 제작 및 성능 분석을 정리하여 기술하였다. 아울러 동일한 형상의 복합재료 전자장비 구조체가 알루미늄 합금의 구조체 대비 질량절감이 가능함을 제시하였다. This paper dealt with an alternative for maximizing mass savings in the spacecraft design by replacing the conventional aluminum alloy structure used for various spacecraft electronics by the composite materials. For the composite electronics structure, key requirements such as the stiffness, thermal conductivity, radiation shielding, EMI protection and electrical conductivity characteristics are defined. The conceptual design of the modular type structure and the design, fabrication and evaluation of the grid-stiffened/monolithic structure using co-curing method, which were already presented and published, are simply described and summarized. Also, the feasibility of the mass savings of the composite electronics structure is illustrated.

CNT의 배향 길이에 따른 CNT-Polyamide 복합재의 특성 변화 연구

김경재,송준혁,박영수,오제하,강신재,양성모 한국기계기술학회 2016 한국기계기술학회지 Vol.18 No.4

The characteristics of CNT-Polyamide composites were analyzed, that is, tensile strength, electrical resistivity, and thermal conductivity were measured according to the align length of CNT. There have been researches on the influence of aligned CNT to improve the mechanical and thermal characteristics in different areas including absorption and shielding of electromagnetic wave, thermal distribution or absorption, and high-strength of CNT. The aligned CNTs were synthesized by the ethylene gas with a CVD device preheated at 650℃. CNT-Polyamide composites were produced with the mixing of solution. CNT contents were controlled from 1phr to 50phr in the polyamide-ethanol solution, and blended with the 700W bar-type ultrasonic wave for 60 min.. And then CNT-polyamide were precipitated by CNT- polyamide-etnanol falling into the cold water. After dried 12 hours, CNT-polyamide composite were pressed at 150℃~180℃ with 400kgf to get the thickness of 1mm. As the conclusions, aligned CNT bundles were dispersed by cutting of CNT to the aligned direction because of polyamide properties. Tensile strength and electrical resistivity were improved to the increase of aligned length of CNT. Thermal conductivity was little affected by the align length of CNT.