Efficient one-step melt-compounding of copolyetheramide/pristine clay nanocomposites using water-injection as intercalating/exfoliating aid

Abstract

Abstract. Polyether-block-amide (PEBA) /clay nanocomposites were prepared water-assisted by twin-screw extrusion. Both organomodified and pristine (i.e. purified but non-modified) montmorillonite clays were used. A high-pressure differential scanning calorimetry analysis carried out in the processing conditions demonstrated that PEBA/water blend exhibits some miscibility and that amide blocks and water behave as a single phase. In addition to a significant decrease of the melting temperature, water injected into the melt plays a key role among the filler dispersion and prevents the matrix from degradation during melt-extrusion. This process enables the compounding of pristine clay-based nanocomposites whose dispersion state is high enough for the resulting mechanical performances in tension to be at least equivalent to what is reached with organomodified clay. Effects of the nanofiller dispersion onto the macromolecules' mobility are detailed and fracture mechanisms are identified for the various structures.

Polyamide 12 (PA12)/clay nanocomposites fabricated by conventional extrusion and water‐assisted extrusion processes

“…This might either indicate that hydrolysis is not significant, or that it is compensated by a reduction of thermal degradation, as the hot points are eliminated by the injection of cold water. Overall, those results are consistent with previous studies involving PA6 5,7 or copolyetheramide, 14 which concluded that hydrolysis during water-assisted extrusion processes remained limited, essentially due to short contact times between polymer and water.…”

“…Their process was further applied by numerous authors to produce PA6, [5][6][7][8] polypropylene (PP) and [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] maleated polypropylene (PP-g-MA), [9][10][11][12] styrene-acrylonitrile (SAN), 13 and copolyetheramide 14 composites based on untreated montmorillonite or other inorganic nanoparticles (e.g., halloysite nanotubes). Delamination of untreated montmorillonite at the nanoscale was readily achieved in PA6.…”

Development of novel melt-compounded starch-grafted polypropylene/polypropylene-grafted maleic anhydride/organoclay ternary hybrids

“…Microscopy is widely used but provides local and qualitative assessment only. Alternatively, dynamic (oscillatory) rheology may provide a semi-quantitative evaluation of the dispersion degree of nanofillers such as carbon nanotubes or layered silicates (montmorillonite among others) in the bulk [8,18,[32][33][34][35]. Also, X-ray diffraction (XRD) analysis allows quantifying the intercalation in the bulk by measuring the clay platelets interlayer distance [35].…”

Response surface analysis of structural, mechanical, and permeability properties of polyethylene/Na+-montmorillonite composites, prepared by slurry-fed melt intercalation

“…But, it brings forth lower chance for nanoclay modification. As a result, this method is best used only for high surface energy polymers [15,16]. It should also be noted that the use of water in producing polymeric nanocomposites is not only limited to polymer/nanoclay composites; this method can be employed to produce polymeric composites from other particles as well [17].…”