Rheology and thermal stability of polymer modified bitumen with coexistence of amorphous phase and crystalline phase

The addition of crystalline polymer into bitumen/SBS blends makes an effect on the phase structure, rheological property and thermal stability. The thermal stability measured by DSC can be improved by the crystalline polymer below 100 °C which is lower than the melting point of single crystalline polymer. Complex modulus and phase angle results suggest that the bitumen/SBS/crystalline polymer blends have much better rheological property rather than the bitumen/SBS blend when the SBS fraction keeps the same in both ternary and binary blends. Among PE, PP, and POM three crystalline polymers, PE is the best candidate for the modification of SBS/bitumen blends. The influence of phase structure on the rheological behavior is investigated, regarding the phase structure type, droplet size and the crystalline or amorphous property.