Effect of the Addition of Chemically Degraded Poly(Ethylene Terephthalate) on the Rheological Properties of Bitumen

The study explores the feasibility of incorporating poly(ethylene terephthalate) (PET) plastomer into processed asphalt through chemical degradation. The depolymerization process involved subjecting the PET plastomer to aminolysis reaction with ethylenediamine. Consequently, the resultant monomer exhibited reduced rigidity and increased machinability. Enhancing its degree of fragmentation facilitated improved homogenization with bitumen. The resulting blend of bitumen and degraded plastomer underwent evaluation for creep resistance in accordance with the Multiple Stress Creep Recovery (MSCR) methodology at a temperature of 64°C. Moreover, fundamental standard tests were conducted, including penetration, softening point, and Fraass breaking point. The incorporation of additional amino groups in the form of degraded PET into the bitumen reduced its susceptibility (Jnr3200 < 0.5 kPa⁻¹) to the creep process and lowered the brittle temperature (approximately –3°C) in comparison to 50/70 neat bitumen. Furthermore, the proposed depolymerization technology for PET and its application to bitumen represents a viable approach for the utilization of PET plastomer.