Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5185104 | Polymer | 2010 | 8 Pages |
Exfoliated layered-silicate in the polystyrene (PS) block copolymer with different molecular weights was employed as a model material to investigate the PS nanocomposite microcellular foams expanded by supercritical carbon dioxide. Using a well-controlled foaming procedure, we investigated the influence of molecular weight of PS, dispersion and loading of layered-silicate and pressure drop rate of a blowing agent on the cell size and cell density. Our experimental results indicate that only exfoliated layered-silicate can inhibit the cell expansion and has high nucleation efficiency during foaming. The average cell diameter can be reduced from 6 μm to 1.4 μm and the cell density can be increased from 7.6 Ã 109 cells/cm3 to 5.0 Ã 1011 cells/cm3. On the contrary, aggregated layered-silicate in PS did not show any effect on the cell morphology of PS foam.
Graphical abstractDownload full-size image