In order to improve the mechanical properties of polypropylene, this paper uses flake talc (TA) filled polypropylene (PP) to enhance the mechanical properties of polypropylene (PP) to improve the applicability of polypropylene. However, when unmodified TA is filled with polypropylene, the surface of unmodified TA is hydrophilic and highly polarized. While the polypropylene (PP) matrix is non-polar and hydrophobic, the difference in surface energy between the two makes the inorganic filler in the polypropylene (PP) matrix prone to agglomeration, weak interfacial bonding, and prone to stress concentration, which will reduce the tensile properties of the material while enhancing the rigidity of the composite. In order to improve the interfacial compatibility and load transfer efficiency, the silane coupling agent γ-aminopropyltriethoxysilane (KH550) was used to modify talc (TA). KH550 was hydrolyzed to generate silanol and condensed with the hydroxyl group on the surface of talc (TA) to form a -Si-O-bond, and at the same time, its organic end-groups enhanced the wettability and interactions in the interfacial area, thus inhibiting the agglomeration and enhancing the stress transfer. The modified talc (TA) and polypropylene (PP) were mixed homogeneously and then extruded into PP/TA composites using twin-screw melt extrusion pelletizing and then extrusion molding. The results showed that the tensile strength of the composite material was the best when the talc (TA) content was 10% and the silane coupling agent γ-aminopropyltriethoxysilane (KH550) concentration was 2%, and the tensile strength reached 32.83 MPa (149% higher than that of pure PP). Talc (TA) content of 20%, silane coupling agent γ-aminopropyltriethoxysilane (KH550) concentration of 2% of the composites of the flexural strength of the most excellent flexural strength reached 48.32 MPa (compared with the pure PP to enhance the 127%), in this paper, by varying the content of talc (TA) and the concentration of silane coupling agent γ-aminopropyltriethoxysilane (KH550) to achieve the inorganic filler from agglomeration to dispersion in polypropylene (PP) matrix. Ideas are provided for the design of polypropylene (PP) composites with excellent performance.
