Research on the optimization of the blending modification process for polypropylene (PP)/polyethylene (PE) and petroleum resin

Herein, hydrogenated C5/C9 petroleum resins, polypropylene (PP), and polyethylene (PE) served as the raw materials. A petroleum resin/PP/PE blend material was prepared through blending modification. The effects of petroleum resin type and loading level were systematically evaluated via tensile, bending, and impact tests and supplemented by microstructural analysis using scanning electron microscopy (SEM). The results indicated distinct optimal addition thresholds for each petroleum resin. For hydrogenated C5 petroleum resin, the tensile strength (32.3 MPa), bending modulus (1242 MPa), bending strength (42.9 MPa), and impact strength (5.76 kJ/m2) all peaked at 2 wt.% loading, while the maximum fracture elongation (17.5%) was achieved at 4 wt.% loading. In contrast, hydrogenated C9 petroleum resin attained the optimal tensile strength (33.0 MPa), bending strength (42.6 MPa), and impact strength (5.33 kJ/m2) at 2 wt.% loading, whereas the highest bending modulus (1257 MPa) and fracture elongation (28.5%) were achieved at 4 wt.% loading. Finally, the fracture surface microstructure of the composite containing 2% petroleum resin was characterized via SEM.