The aim of this work is the evaluation of the effects of plasma treatment and the addition of CNT on the mechanical properties of carbon fibre/PA6 composite. A powder impregnation process with integrated inline continuous plasma of carbon fibers was used to produce CF/PA6 composite. CF/PA6 composite was processed into test laminates by compression moulding, and interface dominated composite properties were studied. The tensile and impact strength of composites containing CNT and plasma‐treated carbon fibres improved obviously. The tensile strength of nanocomposite largely increases with the increasing of the CNT content and then decreases when the CNT content is over 2%. The hydroxyl groups of the fibers surface are in favor of the wettability of carbon fibers by the polar matrix resin, which is resulting in a further interaction of the fiber surface with the curing system of the matrix resin. 相似文献
This paper is concerned with the effects of the plasma surface treatment and the addition of CNT on the mechanical properties of carbon fiber/polytetrafluoroethylene (PTFE) composite. The tensile and flexural strength of composites containing CNT and plasma‐treated carbon fibers improved. The flexural strength first decreases with respect to the CF content. The flexural strength increases to 179 MPa for the plasma‐treated composite as compared with 167 MPa for the neat carbon fiber composites. The overall improvement is thus nearly 8%. 相似文献
Polyamide-6 (PA6)/carbon fiber (CF) composites were prepared by melt-extrusion via continuous fiber fed during extruding. The mechanical, thermal properties, and crystallization behavior of PA6/CF composites were investigated. It was found that the tensile modulus and strength of the composites were increased with the addition of CF, while their elongations at break were decreased. Scanning electron microscopy observation on the fracture surfaces showed the fine dispersion of CF and strong interfacial adhesion between fibers and matrix. Dynamic mechanical analysis results showed that the storage modulus of PA6/CF composites was improved with the addition of CF. Non-isothermal crystallization analysis showed that the CF plays a role as nucleating agent in PA6 matrix, and the α-form crystalline structure was favorable in the PA6/CF composites, as confirmed from the X-ray diffraction analysis. A trans-crystallization layer around CF could be observed by polarizing optical microscopy, which proved the nucleation effect of carbon fiber surface on the crystallization of PA6. The thermal stability of PA6/CF composites was also enhanced. 相似文献
Adverse effects of a high‐water absorption rate on properties of a glass fiber–reinforced polyamide 6 (GF‐PA6) composite significantly reduce performance and limit application in humid environments. In this paper, a polyfunctional silane (PFS) coupling agent with amino (–NH2) and imino (–NH) groups and styrene acrylonitrile copolymer (SAN) were added to a composite, GF‐PA6, to prepare GF‐PA6/SAN/PFS composites via melt blending in a twin‐screw extruder. The effects of SAN and PFS content on the static and dynamic mechanical properties of the composites before and after water absorption were investigated in detail. The microstructure of the fracture surface was analyzed by a scanning electron microscope (SEM). The results show that the addition of SAN and PFS could effectively inhibit water absorption of the GF‐PA6 composites. The alkoxyl groups on PFS reacted chemically with the nitrile groups of SAN, which enriched SAN on the interface between the fiber and matrix during the extrusion and mixing process to improve the effect of water prevention. Therefore, the mechanical properties of the wet state were notably improved while preventing water from permeating the interface by only the addition of a small amount of SAN and PFS. Dynamic mechanical analysis (DMA) results showed that the addition of PFS improved the compatibility of PA6 with SAN and enhanced the interface adhesion between fiber and PA6. In terms of test result of the comprehensive performance, 10 phr SAN with 0.6 phr PFS was the best dosage. 相似文献
A simple and efficient chemical method was developed to graft directly carbon nanofibers (CNFs) onto carbon fiber (CF) surface to construct a CF‐CNF hierarchical reinforcing structure. The grafted CF reinforcements via covalent ester linkage at low temperature without any usage of dendrimer or catalyst was investigated by FTIR, X‐ray photoelectron spectroscopy, Raman, scanning electron microscopy, atomic force microscopy, dynamic contact angle analysis, and single fiber tensile testing. The results indicated that the CNFs with high density could effectively increase the polarity, wettability, and roughness of the CF surface. Simultaneous enhancements of the interfacial shear strength, flexural strength, and dynamic mechanical properties as well as the tensile strength of CFs were achieved, for an increase of 75.8%, 21.9%, 21.7%, and 0.5%, respectively. We believe the facile and effective method may provide a novel and promising interface design strategy for next‐generation advanced composite structures. 相似文献
The mechanical behaviour of fluorosilicone rubber–filled PI composites with and without clay was investigated. The clay filled fluorosilicone rubber composite had the highest interlaminar shear strength value of all the combinations because its higher bond strength may have hindered a large fibre/matrix debonding. The maximum tensile strength was observed for 20 vol% fluorosilicone rubber/PI/5vol%clay composite. The interlaminar shear strength of clay filled fluorosilicone rubber/PI composite was greater than that of fluorosilicone rubber/PI composite, which shows that the adhesion factor of the combination of the PI and fluorosilicone rubber was greater. 相似文献
Flame‐retardant polyamide 6 (PA6) was prepared by an inorganic‐organic composite (MCN or MgO/g‐C3N4) synthesized by incorporating magnesium oxide (MgO) combined with graphitic carbon nitride (g‐C3N4). As compared to g‐C3N4, MCN possessed a laminate structure, more holes, and a larger specific surface area. The addition of MCN could effectively improve the flame retardancy and mechanical properties of PA6 due to its better compatibility and dispersion in the PA6 matrix. When the addition of MCN was 20 wt%, the vertical combustion performance of the PA6/MCN sample reached flammability rating V‐0 (UL‐94) and the limiting oxygen index (LOI) was up to 32.1%. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) revealed that the introduction of MCN efficiently enhanced thermal stability of PA6. The morphologies of the char residue observed by scanning electron microscopy (SEM) verified that MCN promoted the formation of sufficient, compact, and homogeneous char layers on the composite's surface during burning. Thus led to increase the char layer strength and improve the flame retardancy of PA6. The thermogravimetric analysis/infrared (TG‐IR) revealed the gas‐phase retardancy mechanism of MCN. Compared with PA6/g‐C3N4, PA6/MCN showed better mechanical properties in terms of flexural strength and tensile strength. 相似文献
The effect of 1,3,5‐triglycidyl isocyanurate (TGIC) as a synergistic agent on the fire retardancy, thermal, and mechanical properties for polyamide 6/aluminium diethylphosphinate (PA6/AlPi) composites were investigated in detail by limiting oxygen index; vertical burning (UL‐94); cone calorimeter; thermal gravimetric analysis; rheological measurements; and the tests of tensile, flexural, and Izod impact strength. The morphologies and chemical compositions of the char residue were investigated by scanning electron microscopy, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectra. The results demonstrated that AlPi and TGIC exerted an evident synergistic effect for flame retardant PA6 matrix, and the PA6/AlPi/TGIC composites with the thickness of 1.6 mm successfully passed UL‐94 V‐0 rating with the limiting oxygen index value of 30.8% when the total loading amount of AlPi/TGIC with the mass fraction of 97:3 was 11 wt%. However, the samples failed to pass the UL‐94 vertical burning tests when AlPi alone is used to flame retardant PA6 matrix with the same loading amount. The thermal gravimetric analysis data revealed that the introduction of TGIC promoted the char residue formation at high temperature. The rheological measurement demonstrated that the incorporation of TGIC improved the storage modulus, loss modulus, and complex viscosity of PA6/AlPi/TGIC composites comparing with that of neat PA6 and PA6/AlPi composites due to the coupling reaction between TGIC and the terminal groups of PA6 matrix. The morphological structures of char residues demonstrated that TGIC benefited to the formation of more homogenous and integrated char layer with no defects and holes on the surface comparing with that of PA6/AlPi composites during combustion. The higher melt viscosity of composites and the integrated and sealed char layer effectively inhibited the volatilization of flammable gas into the combustion zone and then led to the reduction of the heat release. The results of mechanical properties revealed that the incorporation of TGIC enhanced the mechanical properties for PA6/AlPi/TGIC composites comparing with that of PA6/AlPi composites with the same loading amount of flame retardant caused by the chain extension effect of TGIC. As a result, the flame retardancy and mechanical properties of PA6/AlPi composites simultaneously enhanced due to the introduction of TGIC. 相似文献
The carbon fiber (CF) surface plays a critical role in the performance of CF composite materials. Adipic acid modified epoxy resin potassium (AAEK) prepared with epoxy resin and adipic acid, and KOH was employed as the CF sizing agent. Then, series of surface properties of AAEK‐treated carbon fiber (CF‐AAEK) including surface charge, morphology, and groups were characterized by using Faraday cup, friction coefficient gauge, atomic force microscopy, X‐ray photoelectron spectroscopy, and thermogravimetry. The results indicated that the dispersion coefficient of CF‐AAEK was increased by 1.72 times and there were synergistic effects for the dispersion of short CFs during the sizing treatment process with AAEK. In addition, the flexural strength of treated short CF composite proved to increase by 168%, which evaluated that the better CF dispersion in the matrix was a critical factor for the mechanical property improvement of short CF‐AAEK/epoxy resin composites. 相似文献
Poly(ε-caprolactone)/chitin fiber (PCL-CF) composites as potential bone substitutes were prepared using a simple melt-processing method. The results from differential scanning calorimetry and dynamic mechanical thermal analysis (DMTA) showed that there was interaction between PCL and CF. Static mechanical testing showed that tensile strength, Young’s modulus and flexural strength were increased by the addition of CF. The measurements from DMTA and an advanced rheometric expansion system showed that both the storage modulus and loss modulus were enhanced by CF. The PCL-CF composite with CF of 45% by mass had the best properties among all the tested composites. 相似文献
Summary: A series of molecular composites of PA 6/PA 66 was synthesized via in situ polymerization. The impact resistance of PA 6 was improved dramatically by incorporating a minor amount of PA 66 (2–10 wt.‐%), without decreasing the tensile strength. Inserting PA 66 macromolecules at a molecular level into a PA 6 matrix may interfere with the arrangement of the hydrogen bonds of PA 6, in turn changing the crystalline structure and impeding the crystallization of PA 6.
SEM micrograph of the fractured surface of a PA 6/PA 66 composite containing 10 wt.‐% PA 66. 相似文献