Asphalt modified by the addition of polymers has been used extensively to improve the performance of pavement structures, especially rutting, fatigue and thermal cracking problems can face barriers including segregation, elevated processing temperatures, and decreased low-temperature workability. This study is aimed at investigating the rheological and mechanical properties of modified asphalt binders using PGXpand, a copolymer that has the potential to be an alternative modifier to enhance the performance of asphalt. Extensive experimental program included penetration, softening point, viscosity, ductility and elastic recovery to consider PGXpand-modified asphalt performance in preparation with the performance of SBS-modified asphalt. The results show that PGXpand can improve the stiffness of asphalt binders without degrading the workability. In addition, it shows that PGXpand enhances anti-permanent deformation performance at high temperature which is better than traditional polymer modification. The rheological data also corroborates the beneficial effect of PGXpand on the viscoelastic characteristics of the asphalt binders. These results help in the ongoing development of novel asphalt modifiers, offering a new route for improving the durability of pavements under varying climate conditions and traffic intensity.