Abstract:

Argon plasma combined with coupling agents was employed to modify the surface of poly[ 1, 4-phenylene-cis-benzobisoxazole] ( PBO) fiber. SEM, XPS and droplet profile method were then respectively used to determine the surface morphology, the composition and the contact angle of PBO fibers before and after the treatment.Moreover, the interfacial shearing strengths between PBO fiber and epoxy resin before and after the treatment were finally measured by the single-fiber pull-out tes.It is found that the surface hydrophilicity of PBO fiber and the interfacial shearing streng th between PBO fiber and epoxy resin are greatly improved after the modifica tion, and that,in the conditions of 2% ( mass fraction) of coupling agent ,2min o f treatment period, 30W of power and 50Pa of pressure, the contact angle between the fiber and water reduces fromorig inalmore than 90° to 54. 5° , and the corresponding interfacial shearing strength rises to 10. 44MPa, increasing by 78% . Furthermore, both the interfacial shearing strength and the water hydroph ilic ity of PBO fiber are kept from becoming vestigial after the modification as time progresses.

Key words: PBO fiber, plasma, coupling agent, single-fiber pull-out test, contact angle, epoxy resin