Fabrication Of PSF/MWNTs-Epoxy Hybrid Nanofibers And The Mechanism Of Toughened&Reinforced CFRP Composite Simultaneously

The extensive application of CFRP composites in aviation requiresfor more excellent strength and toughness, especially outstandinginterlaminar fracture toughness. The recent modification of CFRP washard to toughen and reinforce CFRP composite simultaneously whileimproving its heat resistance. In this work, the MWNTs werefunctionalized with epoxy-based groups, and alignedpolysulfone(PSF)/MWNTs-Epoxy hybrid nanofibers with highly orientedMWNTs-Epoxy were electrospun by commercial prepreg attached on arotating drum collector. Then PSF/MWNTs-Epoxy hybrids nanofiberswith different MWNTs-Epoxy loading were used to toughen andreinforce CFRP composite simultaneously.1. MWNTs-Epoxy was prepared via purification, acidification andepoxidation. Purification removed the amorphous carbon, metalimpurities and carbon nanoparticles from the surface of MWNTs. Thegrafting percent of epoxide group was about24.87%. The dispersion ofMWNTs-Epoxy in organic solvents was excellent while the surface tension and electric conductivity was improved with increasingMWNTs-Epoxy loading.2. Aligned PSF/MWNTs-Epoxy hybrid nanofibers with highlyoriented MWNTs-Epoxy were electrospun by commercial prepregattached on a rotating drum collector. The orientation of the hybridnanofibers was perpendicular to carbon fibers in prepreg. Results showedthat the orientation of hybrid nanofibers were improved with increasingMWNTs-Epoxy contents. TEM revealed that an increase in the amount ofMWNTs-Epoxy led to an increase of dispersion homogeneity andorientation degree of MWNTs-Epoxy in hybrid nanofibers.3. CFRP composites were fabricated with the PSF/MWNTs-Epoxyhybrid nanofibers&prepreg by mould pressing. SEM indicated that thereformed a network structure between PSF/MWNTs-Epoxy/Carbonfibers/Epoxy in the interlayer of CFRP composites. The interactionbetween the four phase is primary mechanism of PSF/MWNTs-Epoxyhybrids nanofibers toughened and reinforced CFRP compositesimultaneously. Compared to those CFRP composites toughened andreinforced by PSF/MWNTs-Epoxy hybrid nanofibers with randomorientation, the mechanical and thermal properties of CFRP compositeswith aligned PSF/MWNTs-Epoxy hybrid nanofibers were more excellent.The tensile strength, tensile modulus, interlaminar shear strength and GIICexhibited increase of120.71%,150.70%,7.20%,214.28%, respectively.