Characterization of interfacial properties between fibre and polymer matrix in composite materials – A critical review

Synthetic fibre reinforced polymer (FRP) composite materials have been widely used in engineering fields, e.g., civil, automotive, and aerospace industry, due to their high specific modulus and strength, corrosion resistance, and relatively high durability. The interface between fibre and polymer matrix is critical for the short-term and long-term performance of the FRP composite materials due to the shear lag stress transfer from the matrix to the fibre via their interface. This paper presents an overview of the fibre–matrix interface and interfacial properties. First, the interface mechanisms (i.e., interdiffusion, chemical bonding and mechanical interlocking) of FRP composites are discussed. Next, the methodology for measuring interfacial properties, characterizing interface morphology and chemical composition, and numerical simulations on FRP interface are introduced. Lastly, the challenges for the characterization of interfacial properties are highlighted.