Regulating interfacial compatibility with amino silane and bio-inspired polydopamine for high-performance epoxy composites

The poor interfacial compatibility between functional fillers and matrix greatly restricts development of polymer composites. Therefore, in the present paper, carbon fibers (CFs) were modified by biomimetic polydopamine (PDA) and amino silane (KH550) to improve interfacial bonding strength with epoxy (EP) substrate. The grafting of PDA and KH550 was divided into "PDA", "PDA-KH550" and "(PDA + KH550)" methods for regulating interfacial compatibility and exploring the reaction mechanism. Improved interfacial strength was beneficial to transfer stress from the matrix to fillers. Consequently, mechanical properties of modified CF/EP were obviously superior to those of unmodified EP/CF. Besides, wear resistance of EP/CF-(PDA + KH550) had an increase of 76%, 67%, 60% and 49% compared to that of EP, CF/EP, CF-PDA/EP and EP/CF-PDA-KH550.