A study on montmorillonite/polyethylene nanocomposite extrusion‐coated paperboard

Abstract

Extrusion coating was used to obtain montmorillonite/polyethylene-coated paperboard. The coating was prepared from a master batch containing maleated polyethylene, low-density polyethylene and 32 wt.% polyvinylpyrrolidonesurface-modified montmorillonite clay, which was blended with different amounts of low-density polyethylene to yield composites with 4 wt.% and 8.3 wt.% montmorillonite. X-ray diffraction revealed that the clay stacks in the coating were more extensively intercalated than in the original surface-modified clay. Transmission electron microscopy showed that the clay stacks were, to a large extent, separated by the high shear forces during extrusion into smaller evenly distributed entities. This was, unfortunately, achieved at the expense of the formation of a great many voids and pinholes, as revealed by transmission electron microscopy and dye staining. This had strong negative effects on the oxygen barrier properties but only a modest effect on the water vapour permeability. Tensile tests showed that the coating was always ductile and that the coating-paperboard adhesion decreased with increasing clay content. The creasability was good and unaffected by the presence of the filler in the coating. Thermogravimetry showed that the degradation temperature in air of the filled coatings were of the order of 10°C higher than that of unfilled polyethylene.

Rheological and dynamic mechanical properties of polymer-bonded magnets based on Sm2Co17 and polyamide-12

“…2). This is a common feature of filled polymers and has been suggested to be due to the formation of a ''gel'' at high filler loading with a possible yield point (yield stress) that needs to be overcome in order for a deformation to occur [12][13][14]. As expected, the viscosity increased monotonically with increasing filler content.…”

PFAS in Paper and Board for Food Contact

“…Sizing and coating chemicals which are compatible with the currently used neutral or alkaline pHs include various PFAS sizes and non-fluorinated alkyl ketene dimers (AKD), alkenyl succinic anhydride (ASA) (Roberts 1996), styrene-acrylic copolymers (Yeates et al 1996), talc-filled water-based polyacrylate (Rissa et al 2002), pigment-filled hydrophobic monomer dispersions (Vähä-Nissi et al 2000, 2006, polyvinyl alcohols and montmorillonite/polyethylene-coatings (Krook et al 2005), modified wheat protein, and silicones. Silicone treated paper, used for products like baking paper, is also water repellent but not fat-repellent, but the silicone will let the baked goods release from the paper.…”

Wetting kinetics of oil mixtures on fluorinated model cellulose surfaces

“…They include waxes and wax-metal emulsions [2], styreneacrylic copolymers [3], talc-filled water-based polyacrylate [4], pigment-filled poly(styrene-butadiene) dispersions [5], polyvinyl alcohols [6] and montmorillonite/polyethylene-coatings [7].…”