Extrusion Mixing
Extrusion can be used for mixing and compounding plastics. (RDC 1/14/2011)
Recent US Patents
10/11/2011
8,034,269
Process for the compounding of polymers
Schwemler et al of Bayer, Germany, included (i) melt blending in an extruder at least two polymeric resins to produce a mixture that includes at least one resin that dissociates to yield monomers and/or oligomers upon heating, said mixture containing less than 1 percent of volatile components, (ii) introducing into said extruder an inert entraining agent, and (iii) removing said entraining agent together with said volatile components from said extruder. The extruder includes at least one melting zone, at least two degassing zones and at least one mixing zone. The end product has a particularly low content of residual solvent and at the same time a low content of monomers or oligomers. (RDC 10/13/2011)
Recent Journal Articles
1/7/2011|
Influence of Screw Speed on Electrical and Rheological Percolation of Melt-Mixed High-Impact Polystyrene/MWCNT Nanocomposites
(59–69)Macromolecular Materials and Engineering 296 #1 (2011)
McClory, Pötschke and McNally showed by microscopic observation revealed optimum MWCNT dispersion was achieved at intermediate screw speeds. On addition of MWCNTs to HIPS, the electrical conductivity of HIPS increased by up to 12 orders of magnitude. At screw speeds up to 100 rpm an electrical percolation of 1–3 wt.-% was achieved. This increased to 3–5 wt.-% when the screw speed was increased to 150 rpm. The onset of a rheological percolation was detected for an MWCNT loading of 5 wt.-%, irrespective of screw speed employed. (RDC 1/15/2011)
12/3/2010
One-Step Melt Extrusion Process for Preparing Polyolefin/Clay Nanocomposites Using Natural Montmorillonite
(11896–11905) Industrial & Engineering Chemistry Research 49 #23 (2010)
Ports and Weiss fabricated polyolefin/clay nanocomposites by directly melt compounding poly(ethylene-co-ran-acrylic acid), PEAA, with sodium montmorillonite and a low molecular weight quaternary ammonium salt in a simple process where all the components were fed simultaneously to the extruder. The one-step method was effective at simultaneously dispersing and intercalating/exfoliating the natural montmorillonite and produced nanocomposites comparable to those prepared by melt compounding the PEAA with commercial organoclay. (RDC, 12/8/2010)