Layer-by-layer constructing interface with rigid-flexible transition structure for improving interfacial adhesion of PBO fiber composites

Constructing interface with customized structures of fiber composites is an effective method of achieving high performance. Herein, the comb-like polymer interface with a rigid-flexibility transition structure was constructed on the PBO fiber surface through the layer-by-layer (LBL) method. Compared with original PBO fiber composites, the interfacial adhesion and stability of interface structures were improved significantly due to the LBL construction of comb-like polymers interface. In modified fiber (PBO-P3) composites, the IFSS and ILSS value were increased by 76.30 and 39.31%, respectively. Meanwhile, dynamic mechanical properties and hydrothermal aging resistance were also enhanced obviously. The main contributors for improved interfacial adhesion could be the enlarged interface region with rigid-flexible transition structure, complicated interface contact, enhanced chemical bonding and mechanical interlocking near interface area.