马来酸酐改性高掺量橡胶沥青制备与性能

Preparation and properties of maleic anhydride-modified high-content rubber asphalt

使用高度降解的再生橡胶(DR)制备了高掺量橡胶沥青(HCRA),通过衰减全反射傅里叶变换红外光谱仪、凝胶渗透色谱仪、动态剪切流变仪和动态力学分析仪,对比研究了马来酸酐(MAH)预接枝DR改性与MAH和DR直接共混改性对HCRA结构与性能的影响,探讨了两种改性方法的改性机理。结果表明,MAH预接枝DR时发生了由烯烃双键和烯丙基碳氢原子提供活性位点的自由基取代反应,而MAH和DR与沥青直接共混时,存在自由基取代反应和酯化反应两种反应,并以后者为主;MAH改性HCRA的溶胶组分中以中低分子量组分为主;MAH改性显著改善了HCRA的高、低温流变性能。此外,两种改性方法对HCRA的结构与性能均有影响,且随MAH掺量的变化存在明显差异。

High-content rubber asphalt(HCRA)was prepared by using highly devulcanized rubber(DR),the effects of maleic anhydride(MAH)pre-grafted devulcanized rubber(DR)modification and direct blending modification of MAH and DR on the structure and properties of HCRA were comparatively studied by attenuated total reflection Fourier transform infrared spectrometer,gel permeation chromatography,dynamic shear rheometer and dynamic mechanical analyzer,and the modification mechanisms of two modification methods were explored.The results showed that during the pre-grafting of MAH onto DR,the free radical substitution reaction with active sites provided by olefin double bonds and allyl hydrocarbon atoms occurred,while when MAH and DR were directly blended with asphalt,there were two reactions:free radical substitution reaction and esterification,the latter being the main one.The sol components of MAH-modified HCRA were mainly composed of low and medium molecular weight components.The MAH improved significantly the high-and low-temperature rheological properties of HCRA.In addition,both the modification methods had an impact on the structure and properties of HCRA,and there were significant differences with the change of addition amount of MAH.