Structurally well-defined functionalized polyolefins and graft copolymers thereof as bitumen modifiers

Here we demonstrate the application of hydroxyl-functionalized propylene-based copolymers, poly(propyleneco-1-hexene-co-10-undecen-1-ol) (FPP) and poly(styrene-co-maleic anhydride) (SMA) graft copolymers derived thereof, poly(propylene-co-1-hexene-graft-styrene-co-maleic anhydride) (FPP-g-SMA) as bitumen modifiers. The FPP samples were synthesized via solution copolymerization, while FPP-g-SMA products were obtained via transesterification of FPP with SMA either in solution or by a melt-grafting process. FPP-g-SMA modifiers prepared in solution, having a SMA content of around 30 wt%, performed very well as compatibilizer for bitumen, generating a polymer-modified compositions with a uniform morphology and improved nanomechanical properties, storage stability, rheological properties and high-temperature performance as compared to neat bitumen samples.