The effects of acid-treated MWCNT and coupling agent on properties of MWCNT/SBR are investigated in this work. The MWCNTs oxidized using sulfuric and nitric acids were analyzed by the Raman scattering and Fourier transformed infrared spectroscopy(FT-IR). The FT-IR results indicate the presence of -COOH groups in the treated samples, and Raman spectroscopy of the acidtreated MWCNTs further corroborates the formation of surface defect due to the introduction of carboxyl groups. And the nanocomposites reinforced with MWCNTs were characterized extensively using the scanning electron microscopy(SEM), electrical conductivity, thermal conductivity, and tensile properties measurements. The results showed that nanocomposites onto acid-treated MWCNTs enhanced mechanical properties compared to those containing MWCNTs without acid treatment. These findings confirmed the improved interfacial interactions between MWCNTs and SBR arising from the coupling agents. But the electrical and thermal conductivity of nanocomposites decreased due to the chopping and formation of surface defects of MWCNTs.

본 연구는 MWCNT로 보강된 SBR 나노복합재료를 컴파운딩법(compounding)으로 제조하여 산 처리된 MWCNT와 커플링제 상호간의 물리적·화학적 특성을 조사하였다. 황산과 질산으로 산화된 MWCNT는 FT-IR 분석 결과 -COOH로 기능화됨을 확인하였고, Raman 분석 결과 표면의 defect 존재와 disorder됨을 확인하였다. 또한, 제조된 SBR 복합재료의 가황 특성, 전기적·열적 특성 및 기계적 특성을 비교 평가하였다. 그 결과 산 처리된 MWCNT와 커플링제와의 상호 결합력으로 인해 기계적 물성은 상대적으로 증가하였으나, 전기적·열적 특성은 MWCNT의 defects나 disorder의 형성과 chopping으로 인해 감소됨을 확인할 수 있었다.

Keywords: multi-walled carbon nanotube(MWCNT); styrene butadiene rubber(SBR); coupling agent