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

Abstract

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.

Keywords

• maleic anhydride， devulcanized rubber， high-content rubber asphalt， grafting reaction， modification， reaction mechanism， high- and low-temperature performance，