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Mohammed Naffakh - One of the best experts on this subject based on the ideXlab platform.

  • Inorganic Nanoparticle-Modified Poly(Phenylene Sulphide)/ Carbon Fiber Laminates: Thermomechanical Behaviour.
    Materials (Basel Switzerland), 2013
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh
    Abstract:

    Carbon fiber (CF)-reinforced high-temperature thermoplastics such as poly(phenylene Sulphide) (PPS) are widely used in structural composites for aerospace and automotive applications. The porosity of CF-reinforced polymers is a very important topic for practical applications since there is a direct correlation between void content and mechanical properties. In this study, inorganic fullerene-like tungsten diSulphide (IF-WS2) lubricant nanoparticles were used to manufacture PPS/IF-WS2/CF laminates via melt-blending and hot-press processing, and the effect of IF-WS2 loading on the quality, thermal and mechanical behaviour of the hybrid composites was investigated. The addition of IF-WS2 improved fiber impregnation, resulting in lower degree of porosity and increased delamination resistance, compression and flexural properties; their reinforcement effect was greater at temperatures above the glass transition (Tg). IF-WS2 contents higher than 0.5 wt % increased Tg and the heat deflection temperature while reduced the coefficient of thermal expansion. The multiscale laminates exhibited higher ignition point and notably reduced peak heat release rate compared to PPS/CF. The coexistence of micro- and nano-scale fillers resulted in synergistic effects that enhanced the stiffness, strength, thermal conductivity and flame retardancy of the matrix. The results presented herein demonstrate that the IF-WS2 are very promising nanofillers to improve the thermomechanical properties of conventional thermoplastic/CF composites.

  • Enhancing the thermomechanical behaviour of poly(phenylene Sulphide) based composites via incorporation of covalently grafted carbon nanotubes
    Composites Part A: Applied Science and Manufacturing, 2013
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh
    Abstract:

    Abstract The thermal and thermomechanical properties of poly(phenylene Sulphide) (PPS) based nanocomposites incorporating a polymer derivative covalently anchored onto single-walled carbon nanotubes (SWCNTs) were investigated. The grafted fillers acted as nucleating agents, increasing the crystallization temperature and degree of crystallinity of the matrix. They also enhanced its thermal stability, flame retardancy, glass transition ( T g ) and heat deflection temperatures while reduced the coefficient of thermal expansion at temperatures below T g . A strong rise in the thermal conductivity, Young’s modulus and tensile strength was found with increasing filler loading both in the glassy and rubbery states. All these outstanding improvements are ascribed to strong matrix-filler interfacial interactions combined with a compatibilization effect that results in very homogeneous SWCNT dispersion. The results herein offer useful insights towards the development of engineering thermoplastic/CNT nanocomposites for high-temperature applications.

  • rheological and tribological properties of carbon nanotube thermoplastic nanocomposites incorporating inorganic fullerene like ws2 nanoparticles
    Journal of Physical Chemistry B, 2012
    Co-Authors: Ana M Diezpascual, Mohammed Naffakh, C Marco, Gary Ellis
    Abstract:

    The rheological and tribological properties of single-walled carbon nanotube (SWCNT)-reinforced poly(phenylene Sulphide) (PPS) and poly(ether ether ketone) (PEEK) nanocomposites prepared via melt-extrusion were investigated. The effectiveness of employing a dual-nanofiller strategy combining polyetherimide (PEI)-wrapped SWCNTs with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles for property enhancement of the resulting hybrid composites was evaluated. Viscoelastic measurements revealed that the complex viscosity η, storage modulus G′, and loss modulus G″ increased with SWCNT content. In the low-frequency region, G′ and G″ became almost independent of frequency at higher SWCNT loadings, suggesting a transition from liquid-like to solid-like behavior. The incorporation of increasing IF-WS2 contents led to a progressive drop in η and G′ due to a lubricant effect. PEEK nanocomposites showed lower percolation threshold than those based on PPS, ascribed to an improved SWCNT dispersion due to...

  • Rheological and tribological properties of carbon nanotube/thermoplastic nanocomposites incorporating inorganic fullerene-like WS2 nanoparticles.
    The journal of physical chemistry. B, 2012
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh, C Marco, Gary Ellis
    Abstract:

    The rheological and tribological properties of single-walled carbon nanotube (SWCNT)-reinforced poly(phenylene Sulphide) (PPS) and poly(ether ether ketone) (PEEK) nanocomposites prepared via melt-extrusion were investigated. The effectiveness of employing a dual-nanofiller strategy combining polyetherimide (PEI)-wrapped SWCNTs with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles for property enhancement of the resulting hybrid composites was evaluated. Viscoelastic measurements revealed that the complex viscosity η, storage modulus G′, and loss modulus G″ increased with SWCNT content. In the low-frequency region, G′ and G″ became almost independent of frequency at higher SWCNT loadings, suggesting a transition from liquid-like to solid-like behavior. The incorporation of increasing IF-WS2 contents led to a progressive drop in η and G′ due to a lubricant effect. PEEK nanocomposites showed lower percolation threshold than those based on PPS, ascribed to an improved SWCNT dispersion due to...

  • tuning the properties of carbon fiber reinforced poly phenylene Sulphide laminates via incorporation of inorganic nanoparticles
    Polymer, 2012
    Co-Authors: Ana M Diezpascual, Mohammed Naffakh
    Abstract:

    Abstract Novel carbon fiber (CF)-reinforced poly(phenylene Sulphide) (PPS) laminates incorporating inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles were prepared via melt-blending and hot-press processing. The influence of the IF-WS2 on the morphology, thermal, mechanical and tribological properties of PPS/CF composites was investigated. Efficient nanoparticle dispersion within the matrix was attained without using surfactants. A progressive rise in thermal stability was found with increasing IF-WS2 loading, as revealed by thermogravimetric analysis. The addition of low nanoparticle contents retarded the crystallization of the matrix, whereas concentrations equal or higher than 1.0 wt% increased both the crystallization temperature and degree of crystallinity compared to those of PPS/CF. Mechanical tests indicated that with only 1.0 wt% IF-WS2 the flexural modulus and strength of PPS/CF improved by 17 and 14%, respectively, without loss in toughness, ascribed to a synergistic effect between the two fillers. A significant enhancement in the storage modulus and glass transition temperature was also observed. Moreover, the wear rate and coefficient of friction strongly decreased, attributed to the lubricant role of the IF-WS2 combined with their reinforcing effect. These inorganic nanoparticles show great potential to improve the mechanical and tribological properties of conventional thermoplastic/CF composites for structural applications.

Ana M. Díez-pascual - One of the best experts on this subject based on the ideXlab platform.

  • Inorganic Nanoparticle-Modified Poly(Phenylene Sulphide)/ Carbon Fiber Laminates: Thermomechanical Behaviour.
    Materials (Basel Switzerland), 2013
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh
    Abstract:

    Carbon fiber (CF)-reinforced high-temperature thermoplastics such as poly(phenylene Sulphide) (PPS) are widely used in structural composites for aerospace and automotive applications. The porosity of CF-reinforced polymers is a very important topic for practical applications since there is a direct correlation between void content and mechanical properties. In this study, inorganic fullerene-like tungsten diSulphide (IF-WS2) lubricant nanoparticles were used to manufacture PPS/IF-WS2/CF laminates via melt-blending and hot-press processing, and the effect of IF-WS2 loading on the quality, thermal and mechanical behaviour of the hybrid composites was investigated. The addition of IF-WS2 improved fiber impregnation, resulting in lower degree of porosity and increased delamination resistance, compression and flexural properties; their reinforcement effect was greater at temperatures above the glass transition (Tg). IF-WS2 contents higher than 0.5 wt % increased Tg and the heat deflection temperature while reduced the coefficient of thermal expansion. The multiscale laminates exhibited higher ignition point and notably reduced peak heat release rate compared to PPS/CF. The coexistence of micro- and nano-scale fillers resulted in synergistic effects that enhanced the stiffness, strength, thermal conductivity and flame retardancy of the matrix. The results presented herein demonstrate that the IF-WS2 are very promising nanofillers to improve the thermomechanical properties of conventional thermoplastic/CF composites.

  • Enhancing the thermomechanical behaviour of poly(phenylene Sulphide) based composites via incorporation of covalently grafted carbon nanotubes
    Composites Part A: Applied Science and Manufacturing, 2013
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh
    Abstract:

    Abstract The thermal and thermomechanical properties of poly(phenylene Sulphide) (PPS) based nanocomposites incorporating a polymer derivative covalently anchored onto single-walled carbon nanotubes (SWCNTs) were investigated. The grafted fillers acted as nucleating agents, increasing the crystallization temperature and degree of crystallinity of the matrix. They also enhanced its thermal stability, flame retardancy, glass transition ( T g ) and heat deflection temperatures while reduced the coefficient of thermal expansion at temperatures below T g . A strong rise in the thermal conductivity, Young’s modulus and tensile strength was found with increasing filler loading both in the glassy and rubbery states. All these outstanding improvements are ascribed to strong matrix-filler interfacial interactions combined with a compatibilization effect that results in very homogeneous SWCNT dispersion. The results herein offer useful insights towards the development of engineering thermoplastic/CNT nanocomposites for high-temperature applications.

  • Rheological and tribological properties of carbon nanotube/thermoplastic nanocomposites incorporating inorganic fullerene-like WS2 nanoparticles.
    The journal of physical chemistry. B, 2012
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh, C Marco, Gary Ellis
    Abstract:

    The rheological and tribological properties of single-walled carbon nanotube (SWCNT)-reinforced poly(phenylene Sulphide) (PPS) and poly(ether ether ketone) (PEEK) nanocomposites prepared via melt-extrusion were investigated. The effectiveness of employing a dual-nanofiller strategy combining polyetherimide (PEI)-wrapped SWCNTs with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles for property enhancement of the resulting hybrid composites was evaluated. Viscoelastic measurements revealed that the complex viscosity η, storage modulus G′, and loss modulus G″ increased with SWCNT content. In the low-frequency region, G′ and G″ became almost independent of frequency at higher SWCNT loadings, suggesting a transition from liquid-like to solid-like behavior. The incorporation of increasing IF-WS2 contents led to a progressive drop in η and G′ due to a lubricant effect. PEEK nanocomposites showed lower percolation threshold than those based on PPS, ascribed to an improved SWCNT dispersion due to...

  • Poly(phenylene Sulphide) and poly(ether ether ketone) composites reinforced with single-walled carbon nanotube buckypaper: I – Structure, thermal stability and crystallization behaviour
    Composites Part A: Applied Science and Manufacturing, 2012
    Co-Authors: Ana M. Díez-pascual, Jingwen Guan, Benoit Simard, Marián A. Gómez-fatou
    Abstract:

    Abstract Single-walled carbon nanotube (SWCNT) buckypaper (BP) reinforced-poly(phenylene Sulphide) (PPS) and poly(ether ether ketone) (PEEK) composite laminates were manufactured through hot-press processing. Scanning and transmission electron microscopies were used for morphological characterization and qualitative evaluation of the impregnation degree of the BP. The thermal stability, resin and void content of the composites were evaluated through thermogravimetric analysis; a strong increase in the degradation temperatures of the polymers was found. Raman spectra revealed the existence of strong filler–matrix interactions. The glass transition temperature, crystallization and melting behaviour of the composites were investigated through differential scanning calorimetry and their crystalline structure was analyzed by wide angle X-ray diffraction. This investigation confirms that SWCNT-BPs can be used to fabricate high-loading CNT/thermoplastic composites with improved thermal properties.

  • Grafting of an aminated poly(phenylene Sulphide) derivative to functionalized single-walled carbon nanotubes
    Carbon, 2012
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh
    Abstract:

    Abstract An aminated poly(phenylene Sulphide) derivative (PPS-NH 2 ) has been covalently anchored to the surface of epoxy and acid-functionalized single-walled carbon nanotubes (SWCNTs). The characterisation through Fourier transform infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis and Kaiser test corroborated the success of the grafting reactions, and allowed the identification and quantification of the covalent moieties. Scanning and transmission electron microscopy indicated an increase in the bundle diameter of the SWCNTs upon anchoring of the polymer chains. The results showed that the storage modulus, glass transition temperature and electrical conductivity of the polymer were exceptionally enhanced by the attachment to the SWCNTs. In contrast, the crystallization and melting temperature, degree of crystallinity and crystal size considerably decreased, as revealed by differential scanning calorimetry and X-ray diffraction experiments, due to the inactive nucleating role of these SWCNTs and the intense restrictions on chain mobility imposed by the SWCNT–polymer interactions. Acid-functionalized SWCNTs were more effective for reinforcing PPS-NH 2 than epoxy-functionalized SWCNTs, attributed to the formation of a larger number of covalent bonds, albeit led to a smaller increase in the electrical conductivity of the polymer. The results herein offer useful insights into the development of multifunctional CNT-reinforced thermoplastic composites for a wide variety of applications.

Alain Fradet - One of the best experts on this subject based on the ideXlab platform.

Gary Ellis - One of the best experts on this subject based on the ideXlab platform.

  • rheological and tribological properties of carbon nanotube thermoplastic nanocomposites incorporating inorganic fullerene like ws2 nanoparticles
    Journal of Physical Chemistry B, 2012
    Co-Authors: Ana M Diezpascual, Mohammed Naffakh, C Marco, Gary Ellis
    Abstract:

    The rheological and tribological properties of single-walled carbon nanotube (SWCNT)-reinforced poly(phenylene Sulphide) (PPS) and poly(ether ether ketone) (PEEK) nanocomposites prepared via melt-extrusion were investigated. The effectiveness of employing a dual-nanofiller strategy combining polyetherimide (PEI)-wrapped SWCNTs with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles for property enhancement of the resulting hybrid composites was evaluated. Viscoelastic measurements revealed that the complex viscosity η, storage modulus G′, and loss modulus G″ increased with SWCNT content. In the low-frequency region, G′ and G″ became almost independent of frequency at higher SWCNT loadings, suggesting a transition from liquid-like to solid-like behavior. The incorporation of increasing IF-WS2 contents led to a progressive drop in η and G′ due to a lubricant effect. PEEK nanocomposites showed lower percolation threshold than those based on PPS, ascribed to an improved SWCNT dispersion due to...

  • Rheological and tribological properties of carbon nanotube/thermoplastic nanocomposites incorporating inorganic fullerene-like WS2 nanoparticles.
    The journal of physical chemistry. B, 2012
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh, C Marco, Gary Ellis
    Abstract:

    The rheological and tribological properties of single-walled carbon nanotube (SWCNT)-reinforced poly(phenylene Sulphide) (PPS) and poly(ether ether ketone) (PEEK) nanocomposites prepared via melt-extrusion were investigated. The effectiveness of employing a dual-nanofiller strategy combining polyetherimide (PEI)-wrapped SWCNTs with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles for property enhancement of the resulting hybrid composites was evaluated. Viscoelastic measurements revealed that the complex viscosity η, storage modulus G′, and loss modulus G″ increased with SWCNT content. In the low-frequency region, G′ and G″ became almost independent of frequency at higher SWCNT loadings, suggesting a transition from liquid-like to solid-like behavior. The incorporation of increasing IF-WS2 contents led to a progressive drop in η and G′ due to a lubricant effect. PEEK nanocomposites showed lower percolation threshold than those based on PPS, ascribed to an improved SWCNT dispersion due to...

  • mechanical and electrical properties of carbon nanotube poly phenylene Sulphide composites incorporating polyetherimide and inorganic fullerene like nanoparticles
    Composites Part A-applied Science and Manufacturing, 2012
    Co-Authors: Ana M Diezpascual, Mohammed Naffakh, C Marco, Gary Ellis
    Abstract:

    The mechanical and electrical properties of single-walled carbon nanotube (SWCNT) reinforced poly(phenylene Sulphide) (PPS) composites prepared by melt-extrusion have been evaluated. The wrapping of SWCNTs in polyetherimide (PEI) and the addition of inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles provided an effective method for dispersing the SWCNTs, leading to enhanced properties of the resulting hybrid composites. Mechanical tests demonstrated significant enhancements in stiffness, strength and toughness by the addition of both nanofillers, and the Young’s modulus of the hybrid composites was fairly well predicted by two-phase modelling. The electrical conductivity of PPS improved dramatically at low SWCNT content (0.1–0.5 wt%). At higher concentrations, the replacement of part of the SWCNTs with IF-WS2 maintained the level of conductivity of the composites. Overall, the hybrids possess superior performance than composites reinforced solely with wrapped or non-wrapped SWCNTs, and their properties can be tailored by modifying the SWCNT/IF-WS2 ratio.

  • Mechanical and electrical properties of carbon nanotube/poly(phenylene Sulphide) composites incorporating polyetherimide and inorganic fullerene-like nanoparticles
    Composites Part A: Applied Science and Manufacturing, 2012
    Co-Authors: Ana M. Díez-pascual, Mohammed Naffakh, C Marco, Gary Ellis
    Abstract:

    Abstract The mechanical and electrical properties of single-walled carbon nanotube (SWCNT) reinforced poly(phenylene Sulphide) (PPS) composites prepared by melt-extrusion have been evaluated. The wrapping of SWCNTs in polyetherimide (PEI) and the addition of inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles provided an effective method for dispersing the SWCNTs, leading to enhanced properties of the resulting hybrid composites. Mechanical tests demonstrated significant enhancements in stiffness, strength and toughness by the addition of both nanofillers, and the Young’s modulus of the hybrid composites was fairly well predicted by two-phase modelling. The electrical conductivity of PPS improved dramatically at low SWCNT content (0.1–0.5 wt%). At higher concentrations, the replacement of part of the SWCNTs with IF-WS2 maintained the level of conductivity of the composites. Overall, the hybrids possess superior performance than composites reinforced solely with wrapped or non-wrapped SWCNTs, and their properties can be tailored by modifying the SWCNT/IF-WS2 ratio.

T.g. Gopakumar - One of the best experts on this subject based on the ideXlab platform.