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The continuous carbon fiber reinforced Polyether-ether-ketone (PEEK) prepreg tapes with the addition of carbon nanotubes (CNTs) were prepared by a wet powder impregnation process. Their electrical conductivity, thermal conductivity, the tensile properties, dynamic mechanical behavior, fracture morphology and crystallization melting behavior were investigated. The results show that, the electrical conductivity (σ), thermal conductivity (λ), tensile strength (σ t) and interfacial adhesion of the prepreg tapes were obviously improved with the addition of CNTs. When CNT content was 1.0 wt%, the σ of CNT/CCF/PEEK prepreg tapes in the 0° direction reached a maximum value of 0.701 s cm−1, which was increased 165% than that of CCF/PEEK prepreg tapes. The λ reached 1.053 W m−1·K−1, which was improved by 12.14%. The tensile strength was 1489 MPa, which was increased by 16.4%. The results of SEM images show that the interface adhesion between the fiber and the matrix is good. The results of DMA indicate that, the capability of deformation resistance of the prepreg tapes were further improved with the addition of CNTs. When the temperature was 280 °C, the decline rate of E′ of 1.0 wt% CNT/CCF/PEEK prepreg tapes were 3.58%. The results of DSC indicate that, the T c of CNT/CCF/PEEK prepreg tapes moved to high temperature after adding CNTs, which indicate that CNTs played a role of heterogeneous nucleation in the PEEK matrix.

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It is a challenge to predict the permeability due to the complex correlation between the permeability and structural parameters of fabric preform. In this paper, the correlation between the in-plane permeability and the structural parameters of the non-crimped fabrics is investigated by using the finite element method. The effect of the intra-ply structural parameters and ply orientations on the in-plane permeability of the fabric preform is investigated. In addition, the influence of four structural parameters on the in-plane permeability is analyzed by the Morris method. The results show that the in-plane permeability is most sensitive to the distance between fiber bundles, while the semi-major axis length of the ellipse section of the fiber bundle is relatively insensitive. The order of the in-plane permeability of non-crimped fabrics preform with different ply orientations is as follows: [0]2 > [0/90] > [−45/45]. The present research is helpful to predict permeability and to further simulate resin filling process.

The permeability of the fabric preform is a critical input parameter for analyzing the liquid composite molding impregnation process. However, the permeability prediction is challenging due to its complex dependence on the fabric structure. In this paper, a novel analytical model is developed to predict the permeability of non-crimp fabric preform based on the relation between the pressure drop and geometric parameters of the microchannel cross section. The model takes into account four structural parameters including the width, the height, the semi-major axis length of the ellipse section of fiber bundle and the distance between fiber bundles. The permeability of the unit cell is calculated by the presented analytical model and the finite element simulation, respectively. The results show that the channels between fiber bundles play an important role in determining the fabric permeability. The structural parameters of the unit cell have important effects on the permeability. The new structure-related permeability model can accurately predict the permeability of the non-crimp fabric preform in a certain range.