Multiscale analysis of the mechanical properties and interface damage mechanisms of carbon fiber reinforced polypropylene composites

Abstract In this article, the mechanical properties of carbon fiber reinforced polypropylene (CF/PP) composites at different carbon fiber (CF) mass fractions were systematically investigated. A comprehensive examination is provided through the integration of experimental testing, numerical simulation, and theoretical analysis, revealing the enhancement effects of CF on the polypropylene (PP) matrix across multiple scales. Experimental results demonstrated that the incorporation of CF significantly impedes crack propagation and enhances the fracture resistance of the composites. Specifically, at a CF mass fraction of 15%, the elastic modulus of the composites is enhanced by 21.7% compared with pure PP, while the tensile strength increases by 40.9%–43.2%. The addition of maleic anhydride grafted polypropylene (MAH‐g‐PP) as a compatibilizer significantly improves the interfacial compatibility between CF/PP. Furthermore, finite element simulations revealed the damage evolution process at the CF/PP interface during tensile loading. Based on the Mori‐Tanaka model, the elastic modulus was predicted, aligning well with experimental and simulated results. This research offers a scientific basis for the design and application of CF/PP composites and contributes to the advancement of high‐performance composites. Highlights CF/PP composites show enhancements in mechanical properties with CF addition MAH improves interfacial adhesion between CF and PP, boosting tensile strength Multiscale experimental and FEA studies reveal CF/PP interface damage mechanisms Mori‐Tanaka model accurately predicts the elastic modulus of CF/PP composites