In the present study, carbon fiber coated with multi-walled carbon nanotube (MWCNT), which was modified using a cationic polyethyleneimine (PEI), and acrylonitrile-butadiene-styrene (ABS) resin were used to prepare extruded pellets and long fiber thermoplastic (LFT) pellets, and then carbon fiber/ABS composites were fabricated by injection molding process. The effect of carbon fiber coating with MWCNT on the fiber length distribution, and mechanical and impact properties of resulting composites was investigated. The mechanical properties and impact resistance of the composite prepared by extruded pellets and LFT pellets containing carbon fiber coated with PEI-modified MWCNT were markedly increased. Compared to the composite made with extruded pellets, the composite made with LFT pellets exhibited highly increased length distribution and aspect ratio of carbon fiber. As a result, they significantly contributed to improve the tensile, flexural, and impact properties of the composite, indicating the most profound property improvement on the Izod impact strength.

본 연구에서는 polyethyleneimine(PEI)을 사용하여 multi-walled carbon nanotube(MWCNT)를 개질하고, 이를 코팅한 탄소섬유와 acrylonitrile-butadiene-styrene(ABS)수지를 사용하여 압출펠렛과 long fiber thermoplastic(LFT) 펠렛을 각각 제조하고, 사출성형공정을 통해 탄소섬유/ABS 복합재료를 제조하였다. 복합재료의 섬유길이분포, 기계적 및 충격 특성에 미치는 MWCNT 코팅의 영향을 조사하였다. PEI로 개질한 MWCNT로 코팅한 탄소섬유를 사용하여 압출펠렛과 LFT펠렛으로 제조한 복합재료는 기계적 특성과 충격저항성에서 두드러진 증가를 보여주었다. 압출펠렛보다 LFT펠렛을 사용하여 제조한 복합재료에서 상대적으로 높은 탄소섬유의 길이분포와 종횡비를 나타내었다. 결과적으로 이러한 현상이 복합재료의 인장특성, 굴곡특성 및 충격특성 향상에 중요하게 기여하였으며, Izod 충격강도에서 물성 향상효과가 가장 뚜렷하게 나타났다.

Keywords: multi-walled carbon nanotube coating, polyethyleneimine, carbon fiber/acrylonitrile-butadiene-styrene composites, processing, properties.