In this work, manufacturing tools for thermoplastic (TP) composites have been developed. The chosen process involves the stacking alternately of oriented dry fabrics and TP films and does not use semi-products in orde...In this work, manufacturing tools for thermoplastic (TP) composites have been developed. The chosen process involves the stacking alternately of oriented dry fabrics and TP films and does not use semi-products in order to reduce material costs. This study was specifically directed towards optimizing the impregnation of continuous glass and carbon fibres reinforcing two TP amorphous matrices, the polyphenylsulfone (PPSU) and polyetherimide (PEI), to obtain semi-finished products employed for aeronautical structures. The impregnation quality of inter and intra-yarns is analyzed and validated by optical and scanning micrographic observations conducted with an optical and a Scanning Electron Microscopies (SEM), respectively. The study showed that besides the process parameters and porosity distribution in the core of warp yarns, the impregnation quality depends on the surface properties of constituents. Desizing treatment has been carried out to improve the wettability of fibres by the TP matrices.展开更多
Two different types of graphene flakes were produced following solution processing methods and dispersed using shear mixing in a bifunctional(A) and a multifunctional(B) epoxy resin at a concentration of 0.8 and 0.6 w...Two different types of graphene flakes were produced following solution processing methods and dispersed using shear mixing in a bifunctional(A) and a multifunctional(B) epoxy resin at a concentration of 0.8 and 0.6 wt%, respectively. The graphene/epoxy resin mixtures were used to impregnate unidirectional carbon fibre tapes. These prepregs were stacked(seven plies) and cured to produce laminates.The interlaminar fracture toughness(mode-I) of the carbon fiber/graphene epoxy laminates with resin B showed over 56% improvement compared with the laminate without graphene. Single lap joints were prepared using the laminates as adherents and polyurethane adhesives(Sika 7666 and Sika 7888). The addition of graphene improved considerably the adhesion strength from 3.3 to 21 MPa(sample prepared with resin A and Sika 7888) highlighting the potential of graphene as a secondary filler in carbon fibre reinforced polymer composites.展开更多
文摘In this work, manufacturing tools for thermoplastic (TP) composites have been developed. The chosen process involves the stacking alternately of oriented dry fabrics and TP films and does not use semi-products in order to reduce material costs. This study was specifically directed towards optimizing the impregnation of continuous glass and carbon fibres reinforcing two TP amorphous matrices, the polyphenylsulfone (PPSU) and polyetherimide (PEI), to obtain semi-finished products employed for aeronautical structures. The impregnation quality of inter and intra-yarns is analyzed and validated by optical and scanning micrographic observations conducted with an optical and a Scanning Electron Microscopies (SEM), respectively. The study showed that besides the process parameters and porosity distribution in the core of warp yarns, the impregnation quality depends on the surface properties of constituents. Desizing treatment has been carried out to improve the wettability of fibres by the TP matrices.
基金funding from the European Union Seventh Framework Programme under grant agreement No. 604391Horizon 2020 Programme under grant agreement No. 696656 Graphene Flagship
文摘Two different types of graphene flakes were produced following solution processing methods and dispersed using shear mixing in a bifunctional(A) and a multifunctional(B) epoxy resin at a concentration of 0.8 and 0.6 wt%, respectively. The graphene/epoxy resin mixtures were used to impregnate unidirectional carbon fibre tapes. These prepregs were stacked(seven plies) and cured to produce laminates.The interlaminar fracture toughness(mode-I) of the carbon fiber/graphene epoxy laminates with resin B showed over 56% improvement compared with the laminate without graphene. Single lap joints were prepared using the laminates as adherents and polyurethane adhesives(Sika 7666 and Sika 7888). The addition of graphene improved considerably the adhesion strength from 3.3 to 21 MPa(sample prepared with resin A and Sika 7888) highlighting the potential of graphene as a secondary filler in carbon fibre reinforced polymer composites.
