Key Laboratory of Silicate Materials Science and Engineering of Ministry of Education, Wuhan University of Technology, P. R. China.
J Microsc. 2011 Oct;244(1):85-92. doi: 10.1111/j.1365-2818.2011.03511.x. Epub 2011 Jun 20.
The effect of montmorillonite (MMT) organic modification on microstructures and ultraviolet (UV) aging properties of bitumen was investigated. The microstructures of MMT modified bitumen were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM), respectively. The binders were aged by UV radiation. The UV aging properties of MMT modified bitumen was studied by determining physical properties and AFM analysis. XRD and FTIR analyses show that the sodium montmorillonite (Na(+) -MMT) modified bitumen forms a phase-separated structure, whereas the organo-montmorillonite (OMMT) modified bitumen forms an intercalated structure. After Na(+) -MMT modification, the contrast between the matrix and the dispersed domains is inverted according to AFM analysis. However, this contrast inversion is prevented with the introduction of OMMT due to the good compatibility between the OMMT and the bitumen. As a result of UV aging, both viscosity aging index and softening point increment of OMMT modified bitumen are lower than that of the unmodified bitumen and Na(+) -MMT modified bitumen. Furthermore, the association interactions and single-phase trend in OMMT modified bitumen are further prevented in comparison with Na(+) -MMT modified bitumen during UV aging, indicating the good aging resistance of OMMT modified bitumen after organic modification of MMT.
研究了蒙脱土（MMT）有机改性对沥青微观结构和紫外线（UV）老化性能的影响。分别采用 X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和原子力显微镜（AFM）对 MMT 改性沥青的微观结构进行了表征。用紫外线辐射对粘结剂进行老化。通过测定物理性能和 AFM 分析研究了 MMT 改性沥青的 UV 老化性能。XRD 和 FTIR 分析表明，钠基蒙脱土（Na(+) -MMT）改性沥青形成了相分离结构，而有机蒙脱土（OMMT）改性沥青形成了插层结构。根据 AFM 分析，Na(+) -MMT 改性后，基质与分散相之间的对比度发生反转。然而，由于 OMMT 与沥青之间的良好相容性，引入 OMMT 可防止这种对比度反转。由于 UV 老化，OMMT 改性沥青的粘度老化指数和软化点增量均低于未改性沥青和 Na(+) -MMT 改性沥青。此外，与 Na(+) -MMT 改性沥青相比，OMMT 改性沥青在 UV 老化过程中进一步阻止了缔合相互作用和单相趋势，表明 MMT 有机改性后的 OMMT 改性沥青具有良好的耐老化性能。
