The surface modification of continuous fiber was conducted by the inductive coupling radio frequency cold plasma (ICP) technique.The influence of the plasma parameters

such as treatment time

discharge pressure

power

etc.on the surface chemical composition

surface morphology

surface roughness and surface free energy of continuous fiber was systematically studied by X-ray photoelectron spectroscopy (XPS)

atomic force microscopy (AFM) and dynamic contact angle analysis (DCAA)

respectively.Results showed that the plasma treatment introduced some polar groups such as O—C O onto the continuous fiber surface

increasing the percentage of surface polar groups;the plasma etched the fiber surface obviously

enhancing the surface roughness and surface free energy and improving the wettability of the fiber distinctly.Plasma treatment conditions should be appropriate during surface modification of fibers by clod plasma.After CF was treated for 5 min

CF surface polar group was increased to a relatively higher level.However

the effect of plasma etching on CF surface is relatively slower.After CF was treated for 5 min

CF surface roughness was changed a little.However

after CF was treated for more than 15 min CF surface roughness was increased significantly.Based on the study above

the interfacial adhesion and fracture mechanism of continuous fiber reinforced soluble polyaromatic ether resin composites was also systematically analysed by interlaminar shear strength (ILSS)

water absorption and scanning electron microscopy (SEM) measurements.It was found that CF reinforced poly (phthalazinone ether sulfone ketone) (PPESK) composite interfacial adhesion mechanism analysis indicats that both chemical bonding and mechanical interlocking interaction has a positive effect on composite interfacial adhesion

however

mechanical interaction has a dominant effect on composite interfacial adhesion than chemical bonding interaction.Armos aramid fiber composite interlaminar shear strength increased from 59.5 MPa for untreated sample to 68.8 MPa for plasma treated for 10 min under discharge power at 200 W

with an increase of 15.6%.The water absorption decrease of composite also indirectly showed that oxygen plasma treatment improved composite interfacial adhesion.The primary failure mode of Armos aramid or PBO/PPESK composites shifted from interface failure to matrix fracture after oxygen plasma treatment.The interfacial adhesion of Armos aramid or PBO/PPESK composites was improved by oxygen plasma treatment due to the chemical linkage and mechanical bonding between Armos aramid or PBO fibers and PPESK matrices

and the chemical linkage effect exhibits more contribution than the mechanical bonding.