Probing the Effect of Grafting Glycidyl Methacrylate Onto Waste Low‐Density Polyethylene on the Properties of Modified Asphalt

ABSTRACT The WPE‐ g ‐GMA modifier was prepared by reactive melt grafting of glycidyl methacrylate (GMA) to enhance the interfacial interaction between waste low‐density polyethylene (WPE) and asphalt. The effects of GMA grafting on the physicochemical properties and microstructure of modified asphalt were systematically investigated. When evaluating the macroscopic performance of modified asphalt, it was found that varying the grafting content of GMA on WPE has a limited effect on improving the penetration and softening point of WPE modified asphalt, while significantly enhancing its ductility. In contrast, the penetration and softening point can be improved by increasing WPE‐ g ‐GMA content, but at the expense of ductility. The epoxy groups of GMA react with active sites in the asphalt to form covalent bonds, which significantly enhances the thermal storage stability of WPE‐ g ‐GMA modified asphalt. However, as the content of WPE‐ g ‐GMA increases, the particle size grows and the size distribution becomes broader. These large particles are susceptible to floating, leading to reduced thermal storage stability. While GMA grafting compromises the high‐temperature performance of WPE‐ g ‐GMA modified asphalt by reducing WPE crystallinity, the enhanced interfacial interaction and increased WPE‐ g ‐GMA particle content synergistically enhance the rutting resistance at high temperature of the modified asphalt.