Study on the effect of fiber-matrix interface on mechanical response of carbon fiber fabrics reinforced polyether ether ketone composites

Carbon fiber fabrics reinforced polyether ether ketone (CFF/PEEK) composites show extraordinary mechanical properties which deeply relay on their interfacial properties. Herein, two simple desizing method of acetone and high-temperature were used to remove sizing agent of CFF. The fiber surface roughness and surface activity increased after desizing, which enhances interfacial wettability between fiber and resin. The interface shear strength (IFSS) measured by micro-bond test was used to evaluated the interfacial properties. After desizing, the IFSS enhanced from 41.7 to 51.2 MPa, which may be owing to enhanced of interfacial adhesion and mechanical locking between CFF and PEEK. CFF/PEEK laminates were fabricated by a simple film stacking method using hot-pressing process of CFF and PEEK film. Interlaminar shear strength (ILSS) tested by short-beam method increased from 62.5 to 71.3 MPa, and flexural strength increased from 754.4 to 805.5 MPa, which indicated the fiber-matrix interface enhanced. Furthermore, forming quality and microscopic failure modes of CFF/PEEK verified fiber-matrix interface enhanced after removing sizing agent. The interfacial and mechanical properties of CFF/PEEK composites significantly enhanced by using simple and effective desizing method. This study is expected to provide valuable insights into optimizing fiber surface treatments for enhancing durability and reliability of advanced composite materials.Highlights Acetone and high-temperature desizing were used to remove sizing agent of CFF. The IFSS of treatment CFF increased over 25% compared with untreated ones. The ILSS and flexural strength of desizing-CFF/PEEK enhanced notably. The fiber-matrix interface between desizing-CFF and PEEK resin enhanced.