The present invention discloses a polypropylene resin with low melt index, high modulus and high impact resistance, and a preparation method and application thereof, belonging to the technical field of polymer synthesis. The preparation method provided by the present invention comprises the following steps: adding an external electron donor, a main catalyst, a co-catalyst and refined propylene into a polymerization kettle, introducing hydrogen and conducting polymerization to obtain polypropylene powder; mixing the polypropylene powder with a main antioxidant, an auxiliary antioxidant, calcium stearate, a β-crystal nucleating agent and ethylene-containing copolymerized polypropylene resin, and extruding and pelletizing by a twin-screw extruder to obtain the product. By adding appropriate additives, the polypropylene resin prepared by the present invention has both high rigidity and high toughness, with a flexural modulus of more than 1600 MPa, normal-temperature impact strength of more than 110 kJ/m², low-temperature impact strength (-20℃) of more than 5 kJ/m², and a melt index of less than 0.3 g/10 min. It is suitable as a special material for polypropylene winding sewage pipes and meets the Grade A index of melt mass flow rate in GB/T 35451.2-2018.
Country Code: CN
Application Number: CN202410819100.0
