염수환경에 노출된 철도차량용 탄소섬유/에폭시 복합재의 내구성 평가

국문 초록 (Abstract)

본 연구에서는 염수분무환경에 노출된 철도차량 차체용 탄소섬유/에폭시 복합재의 내구성을 조사하였다. 염수환경시험을 위해서는 해수와 가장 유사하도록 5% 염화나트륨 염수용액을 제조하여 사용하였다. 본 연구에 적용된 시편은 T700 탄소섬유직물을 에폭시 수지에 함침시킨 형태의 복합재 평판에서 채취하였다. 기계적 특성 시험을 통해 인장특성, 굽힘특성, 전단특성을 평가하였으며 동역학 측정장치를 통해 저장탄성계수, 손실탄성계수, 그리고 tan δ 등의 열분석 특성을 평가하였다. 또한 적외선 분광분석을 통해 노출기간에 따른 화학구조 변화도 조사하였다. 연구결과에 따르면 강화섬유가 지배적인 역할을 하는 기계적 특성은 염수환경에 영향을 받지 않지만 수지가 지배적인 역할을 하는 기계적 특성은 노출기간이 길어짐에 따라 점차 감소하는 양상을 나타낸다. 저장탄성계수는 노출기간에 큰 영향을 받지는 않지만 유리전이온도는 염수환경에 영향을 받으며 노출기간이 길어지면 감소하는 양상을 나타낸다. FT/IR 선도에서 관찰된 피크의 세기는 노출기간에 다소 영향을 받지만 피크의 형상과 위치는 노출기간에 따른 변화가 관찰되지 않는다. 이로 미루어 볼 때 본 연구에 적용된 탄소섬유/에폭시 복합재는 염수환경에 비교적 안정함을 알 수 있다.

다국어 초록 (Multilingual Abstract)

This study investigates the durability of carbon/epoxy composites for use on train car bodies under a salt water spray environment. Salt water solution with 5% NaCl, similar to natural salt water, was used for the salt water environmental tests. The specimens were obtained from a composite panel consisting of an epoxy matrix reinforced with T700 carbon fabric. The specimens were exposed to the salt water environment for up to 12 months. Mechanical tests were performed to obtain tensile properties, flexural properties, and shear properties. Dynamic mechanical analysis was used to measure such thermal properties as storage modulus, loss modulus, and tan δ. Also FT/IR tests were conducted to investigate changes in chemical structure with exposure. The results revealed that fiber-dominated mechanical properties were not affected much by exposure time, but matrix-dominated mechanical properties decreased with increasing exposure time. Storage modulus was not very sensitive to exposure time, but glass transition temperature was affected, slightly decreasing with increasing exposure time. Although the peak intensity of FT/IR curves was affected slightly by exposure time, the peak shape and peak location of FT/IR curves were not noticeably changed. Carbon/epoxy composites used for this study were relatively stable to the salt water environment.

목차 (Table of Contents)

• Abstract
• 요지
• 1. 서론
• 2. 시편 제작 및 실험 방법
• 3. 시험 결과 및 고찰
• 4. 결론
• 참고문헌

참고문헌 (Reference)

• 1 Kootsookos, A., "Seawater Durability of Glass- and Carbon-Polymer Composites" 64 : 1503-1511, 2004
• 2 Caceres, A., "Salt-Fog Accelerated Testing of Glass Fiber Reinforced Polymer Composites" 2002
• 3 Fried, J. R., "Polymer Science and Technology" Prentice- Hall of India 2003
• 4 Wolff, E. G., "Moisture Effects on Polymer Matrix Composites" 29 (29): 11-19, 1993
• 5 Donald, L. P., "Introduction to Spectroscopy" Saunders College Publishing 1998
• 6 Zhang, S., "Evaluation of Property Retention in E-Glass/Vinylester Composites after Exposure to Salt Solution and Natural Weathering" 19 (19): 704-731, 2000
• 7 Yoon, S. H., "Evaluation of Durability for Glass Fabric/Phenolic Composites under Salt Water Environment" 18 (18): 27-33, 2005
• 8 Hammami, A., "Durability and Environmental Degradation of Glass-Vinylester Composites" 25 (25): 609-616, 2004
• 9 Catherine, A. W., "Determination of the Effect of Seawater on the Interfacial Strength of an Interlayer EGlass/ Graphite/Epoxy Composite by in SITU Observation of Transverse Cracking in an Environmental SEM" 57 : 1033-1043, 1997
• 10 Jamond, R. M., "Composites in Simulated Marine Environments" NFESC Special Publication 2000
• 11 Jamond, R. M., "Accelerated Testing of Fiber Reinforced Polymer Matrix Composites - Test Plan" NFESC Special Publication SP-2091- SHR 2000
• 12 "ASTM D790-00, Annual Book of ASTM Standards, 08.01, American Society for Testing and Materials"
• 13 "ASTM D5379/D5379M-98, Annual Book of ASTM Standards, 15.03, American Society for Testing and Materials"
• 14 "ASTM D3039/D3039M-00, Annual Book of ASTM Standards, 15.03, American Society for Testing and Materials"
• 15 "ASTM B117-97, Annual Book of ASTM Standards, 03.02, American Society for Testing and Materials."