硅⁃铝包覆TiO_(2)功能化SBS改性沥青抗老化机理及性能研究

Study on anti⁃aging mechanism and performance of asphalt modified with Si⁃Al coated TiO_(2)⁃functionalized SBS

为更好地利用纳米二氧化钛(TiO_(2))优良的紫外线屏蔽功能,提高苯乙烯⁃丁二烯⁃苯乙烯嵌段共聚物(SBS)改性沥青的抗老化性能,解决TiO_(2)因纳米效应难以在SBS改性沥青体系中分散,同时纳米TiO_(2)具有的光催化活性对SBS改性沥青材料进行氧化,导致SBS改性沥青抗老化性能减弱等问题,本文在纳米TiO_(2)表面采用硅⁃铝共沉淀法形成包覆膜,通过透射电子显微镜(TEM)、X射线衍射(XRD)技术分析了包覆效果及包覆体物相结构,应用紫外分光光度法检测了功能化改性沥青的紫外线吸收能力,通过扫描电子显微镜(SEM)、荧光显微镜技术分析了硅⁃铝包覆手段对TiO_(2)及SBS分散性及稳定性的影响,采用红外光谱技术揭示了硅⁃铝包覆TiO_(2)功能化SBS改性沥青的抗老化机理,最后对功能化改性沥青性能进行了分析研究。结果表明,硅⁃铝包覆TiO_(2)含量为6.0%时,可有效提高TiO_(2)与SBS在沥青中的分散性与稳定性,阻断TiO_(2)光催化活性对改性沥青的氧化作用,提高了SBS改性沥青的抗老化性。

In order to better utilize the excellent UV shielding function of nano⁃TiO_(2),improve the anti⁃aging performance of SBS⁃modified asphalt,and address a difficulty in the dispersion of nano⁃TiO_(2)in the SBS⁃modified asphalt system,the Si⁃Al coated nano⁃TiO_(2)was prepared using a Si⁃Al coprecipitation method to form the coating film on the surface of nano⁃TiO_(2).This approach can effectively prevent the oxidation of SBS⁃modified asphalt caused by nano⁃TiO_(2)due to its photocatalytic activity and thus enhance the anti⁃aging performance of nano⁃TiO_(2)⁃functionalized SBS⁃modified asphalt.The coating effect and morphological microstructure of the coated nano⁃TiO_(2)were investigated by TEM and XRD,the ultraviolet(UV)absorption capacity of the modified asphalt was analyzed by UV spectrophotometry,the influence of Si⁃Al coating on the dispersion and stability of nano⁃TiO_(2)and SBS was evaluated by SEM and fluorescence microscopy,and the anti⁃aging mechanism of the Si⁃Al coated nano⁃TiO_(2)functionalized SBS⁃modified asphalt was analyzed by FTIR spectroscopy.Finally,the performance of the functionalized SBS⁃modified asphalt was studied.The results indicated that the dispersion and stability of nano⁃TiO_(2)and SBS in asphalt were effectively improved when 6 wt%Si⁃Al coated nano⁃TiO_(2)was incorporated.In this case,the oxidation effect of nano⁃TiO_(2)on the modified asphalt could be suppressed,and the anti⁃aging performance of the SBS⁃modified asphalt could be improved.