Preparation and properties of nano‐CaCO3/waste polyethylene/styrene‐butadiene‐styrene block polymer‐modified asphalt

Abstract

AbstractPolymer and nanomaterial modifiers can improve the performance of asphalt, and how to utilize the synergistic effect for modifying asphalt is still a problem. In this article, modified asphalt by waste polyethylene (WPE)/styrene‐butadiene‐styrene block polymer (SBS) in different proportions was prepared via a melting‐mixing method. Then, the WPE/SBS‐modified asphalt with an optimum modifier content was further modified by nano‐CaCO3 into different shapes. The performances of modified asphalt were investigated by thermal gravimetry (TG), differential scanning calorimetry (DSC), dynamic shear rheological test (DSR), and Fourier transform infrared spectroscopy (FTIR), and the morphology was observed by fluorescence microscopy. The results showed that the penetration of modified asphalt increased and the ductility decreased with the increase of WPE content. In addition, the softening point increased with the increase of WPE/SBS content. For the modified asphalt with 4 wt% composite modifier (40 wt% WPE+60 wt% SBS), the ductility was improved after adding nano‐CaCO3 whiskers. However, the ductility slightly decreased when the content of nano‐CaCO3 particles increased, resulting in negative effects. The WPE content in WPE/SBS modifier was optimized to 40 wt%, and the performance of modified asphalt can satisfy the requests in practical applications, thus providing an economical access to reuse packaging waste.