Influence of Ozone Treatment on the Surface Characteristics of Montmorillonite and the Thermal Stability of Montmorillonite/polypropylene Nanocomposites

오존처리가 몬모릴로나이트의 표면특성 및 몬모릴로나이트/폴리프로필렌 나노복합재료의 열안정성에 미치는 영향

  • 진성열 (한국화학연구원 화학소재연구부) ;
  • 이재락 (한국화학연구원 화학소재연구부) ;
  • 박수진 (한국화학연구원 화학소재연구부)
  • Published : 2005.02.01

Abstract

In this work, the effect of ozone treatment of montmorillonite (MMT) on the surface characteristics of montmorillonite and the thermal stability of MMT/polypropylene (PP) nanocomposites was investigated. The surface properties of MMT were determined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS). Also, the thermal stability of nanocomposites was investigated in thermogravimetric analysis (TGA). As a result, it was found that the silicate interlayers of the organically modified MMT (D-MMT) were increased by about 11${\AA}$, as compared with the MMT. Also, FT-IR showed that a new peaks at $2800\~2900\;cm^{-1}$ appeared due to the $CH_2$ mode in the D-MMT The ozone treatment of the MMT led to an increase of SiO or $SiO_2$ groups on MMT surfaces, resulting in increasing the oxygen-containing functional groups on MMT. The ozonized MMT had higher thermal stability than that of untreated nanocomposites. This was due to the improvement of interfacial bonding strengths, resulting from the acid-base interfacial interactions between PP and MMT.

본 연구에서는 몬모릴로나이트(montmorillonite, MMT)의 오존처리가 몬모릴로나이트의 표면특성과 폴리프로필렌(polypropylene, PP) 나노복합재료의 열안정성에 미치는 영향에 대하여 살펴보았다. MMT의 표면 특성은 XRD, FT-IR 그리고 XPS를 통해 관찰하였고, 나노복합재료의 열안정성은 열중량 분석기(TGA)를 이용하여 조사하였다 실험 결과, 실리케이트의 층간 간격은 유기적으로 개질된 MMT(D-MMT)가 개질되지 않은 MMT에 비해 약 11${\AA}$ 증가한 것을 알 수 있었고, FT-IR 결과로부터 D-MMT의 경우 $2800\~2900\;cm^{-1}$ 부근에서 $CH_2$의 피크가 형성된 것을 확인할 수 있었다. 또한 오존처리는 MMT 표면에 Si-O와 $SiO_2$ 관능기를 증가시켰는데, 이는 산소를 포함하는 관능기들이 발달하기 때문으로 판단된다. 오존처리된 MMT가 도입된 나노복합재료에서 열안정성이 증가하는 것을 확인할 수 있었으며, 이는 PP와 MMT 사이의 산-염기 계면 상호작용으로부터 계면 결합력이 향상되었기 때문으로 판단된다.

Keywords

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