Improved interfacial adhesion in carbon fiber/polyether sulfone composites through an organic solvent-free polyamic acid sizing

- A novel organic solvent-free polyamic acid (PAA) sizing was synthesized.
- The PAA sizing was obtained in the form of colloidal nanoemulsion.
- The PAA sizing layer obviously enhanced the surface wettability of carbon fibers.
- The interfacial shear strength of carbon fiber/PES was increased by 47.9% due to the sizing.
- The mechanism of interfacial adhesion of coated carbon fiber/PES was demonstrated.