Plastic deformation behaviour of thermoplastic/clay nanocomposites

Thermoplastic Nanocomposites and Their Processing Techniques

“…TEM images confirmed the predicted morphologies (Figure 4a, b,d,e). The enhanced thermal stability for these systems was attributed partially to barrier properties (Gloaguen & Lefebvre, 2001). Fig.…”

“…Based on the interaction of silicates with polymer, polymer/layered silicate nanocomposites are classified into( Figure 2); (a) intercalated nanocomposites (inserted polymer chains in the layered silicate structure in a crystallographically regular fashion, irrespective of the polymer to clay ratio with a repeat distance of few nm), (b) flocculated nanocomposites, (intercalated and stacked silicate layers flocculated to some extent due to the hydroxylated edge-edge interactions of the silicate layers), and (c) exfoliated nanocomposites (separated individual silicate layers in the polymer matrix; the distance depends on the clay loading) (Ray & Okamoto, 2003) . The strong interactions of polymer with layered silicate in polymer/silicates nanocomposites lead to the dispersion of organic and inorganic phases at the nm level, resulting in improved tensile properties ), high moduli (Vaia et al, 1999), increased strength and heat resistance, (Pattanayak et al, 2005), thermal stability (Xu et al, 2004),decreased gas permeability , and flammability (Gilman et al, 2000), and increased biodegradability (Gloaguen et al, 2001), not shown by their conventionally filled microcounterparts (Ray & Okamoto 2003). (Vaia et al, 1994).…”

“…In case of nylon6, it was clear that the usual shear banding plastic deformation mode was altered in its initiation step. Localised interfacial damage promoted extensive polymer matrix brillation and fracture occurred predominantly in areas where delamination of the clay platelets was not fully achieved (Gloaguen & Lefebvre, 2001). …”

Volume Variation Process of High-Density Polyethylene During Tensile and Creep Tests

“…Concerning the ultimate dilatation phenomenon, it has been documented in details by many authors [10,12,16], who ascribed it both to the destruction of crystalline order and to the development of voids. Since we found that the progressive loss of crystallinity on stretching is of the order of 30% (see Fig.…”

“…Although the above techniques are still applied by some researchers, the computerized video techniques developed during the last decade brought a decisive contribution to the assessment of volume strain in polymers. Originally, they were limited to the pre-necking deformation stage [12,[14][15][16][17]. However, the novel video-controlled testing system that was recently developed in this laboratory has several interesting features [18]: -it provides in real time the true stress/strain behavior locally within a representative volume element (RVE) situated at the center of the neck; -it gives access to the volume strain in the same RVE; -it allows the user to regulate dynamically either true strain rate (for tensile tests) or true stress (for creep tests).…”