Effects of Blend Composition and Nanoclay on Cell Structure of Microcellular-Foamed Polypropylene/Polystyrene Blends

摘要

The supercritical carbon dioxide foaming behaviors of polypropylene/polystyrene (PP/PS) blends and their nanocomposites with 3 wt% nanoclay using a pressure vessel were investigated. The cell size increased and the cell density decreased with the increase of PS content. Dispersed PS phase with more uniform distribution was favorable to produce much more uniform cellular structure. The addition of a small amount of nanoclay, which acts as a nucleation agent, reduced the cell size and increased the cell density of PP/PS blends further. Microcellular foams with mean cell diameters of 0.80–7.13 μm and cell densities of 2.50×10~9–3.96×10~(11) cells/cm~3 were produced from blends and their nanocomposites.