Élaboration et caractérisation de nanocomposites polyéthylène/montmorillonite

Revue de littérature -- Objectifs et organisation générale du document -- Travaux préliminaires, partie 1 : élaboration de montmorillonites organophiles à haute stabilité thermique -- Travaux préliminaires, partie II : nanocomposites polyéthylène/montmorillonite : sélection des matériaux -- Article 1 : Thermal decomposition of various alkyl onium organoclays : effect on polyethylene terephtalate nanocomposites properties -- Article 2 : effect of intercalating agents on clay dispersion on the properties of LLDPE/LLDPE-G-MAH/Montmorillonite nanocomposites -- Discussion générale

High refractive index composite materials for THz waveguides: trade-off between index contrast and absorption loss

Polymer compounds from titania-doped polyethylene are fabricated and their linear optical properties characterized by THz-TDS. We show that high concentration of dopants not only enhances the refractive index of the composite material, but also can dramatically raise its absorption coefficient. We demonstrate that the design of Bragg reflectors based on lossy composite polymers depends on finding a compromise between index contrast and corresponding losses. A small absorption value is also shown to be favorable, compared to an ideal lossless reflector, as it enables to smooth the transmission passbands. Transmission measurements of a fabricated hollowcore Bragg fiber confirm simulation results

Use of Thermal Black as Eco-Filler in Thermoplastic Composites and Hybrids for Injection Molding and 3D Printing Applications

Thermal black (TB) is one of the purest and cleanest forms of carbon black (CB) commercially available. TB is manufactured by the decomposition of natural gas in the absence of oxygen while the common furnace CB is derived from the burning of organic oil. TB has a larger particle size, a lower surface area, and lower level of particle aggregation, while being the most eco-friendly grade among the CB family. This study is the first-time evaluation of TB as filler in composites and hybrids based on thermoplastics such as polypropylene (PP), polyamide 6 (PA6), polyphenylene sulfide (PPS), and acrylonitrile butadiene styrene (ABS). TB loadings in composites were varied from 1 up to 40 wt. % and, in hybrids, the TB was used in combination with carbon fibers (CFs) at total contents up to 20 wt. %. TB-containing composites and hybrids based on PA6 and ABS were also extruded in filaments, used in 3D printing, and the obtained 3D printed parts were characterized. TB provided a very high loadability in thermoplastics while preserving their viscosity and performance. TB can replace a fraction of expensive CFs in composites without important changes in the composites’ performance. The composites and hybrids exhibited electrical resistivity and good mechanical and thermal properties when compared to commercial compounds, while enabling significant cost savings. TB also showed to be an excellent coloring agent. TB proved to be an outstanding eco-filler for compounds to be used in injection molding and 3D printing technologies

Greener polypropylene compounds for automotive interiors

NRC publication: Ye

All-polymeric photonic bandgap polystyrene/polymethylmethacrylate Bragg fibers

Peer reviewed: YesNRC publication: Ye

Deformation and fracture mechanisms in polyethylene / clay nanocomposites

Polyethylene/montmorillonite nanocomposites based on LDPE, HDPE and LLDPE of similar rheological properties were prepared and mechanically tested in tension mode. It was shown that nanocomposites based on LLDPE exhibit a very peculiar behaviour, with a significant improvement in toughness (elongation at break). The mircorstructural features of the various nanocomposites were investigated through scanning and/or transmission electron microscopy. Based on those observations, an explanation for the deformation and fracture mechanisms in LLDPE/montmorillonite nanocomposites was proposed.Peer reviewed: YesNRC publication: Ye