Excellent and effective interfacial transition layer with an organic/inorganic hybrid carbon nanotube network structure for basalt fiber reinforced high-performance thermoplastic composites

Basalt fiber reinforced high-performance thermoplastic (BFRHTP) composites are promising materials for application in military, aerospace, chemical, automobile, and other high-tech industries. However, their mechanical properties are still largely limited by poor interfacial properties because of the smooth, inert, and low-energy surface of BF. In this study, an organic/inorganic hybrid sizing agent was used for BF surface modification to construct an appropriate modulus transition layer for the interface with a combination of soft and rigid phases. Organic poly(ether nitrile) (PEN) and inorganic carboxylic multi-walled carbon nanotubes (MWCNT-COOH) in hybrid sizing agents (PEN/CNT) were respectively used as soft and rigid phases to design the interfacial structure. The tensile strength, flexural strength, interlaminar and interfacial shear strength of the basalt fiber reinforced poly(phthalazinone ether nitrile ketone) composites were increased by 60, 33, 62, and 144%, respectively. This approach provides a simple, green, and promising strategy for enhancing the interfacial properties of BFRHTP composites.