Polymer nanocomposite foams
The present invention is in the field of polymer foams. Specifically, the present invention relates to polymer nanocomposite foams. Nano-sized particles such as nano-clays can be mixed with polymers through either melt compounding or in-situ polymerization. By modifying the particle surface with var...
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Main Authors | , , , , |
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Format | Patent |
Language | English |
Published |
06.07.2004
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Online Access | Get full text |
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Summary: | The present invention is in the field of polymer foams. Specifically, the present invention relates to polymer nanocomposite foams.
Nano-sized particles such as nano-clays can be mixed with polymers through either melt compounding or in-situ polymerization. By modifying the particle surface with various surfactants and controlling processing conditions, we are able to achieve either intercalated (partial dispersion) or exfoliated (full dispersion) nano-clay distribution in polymers with the clay content up to 35% by weight. When a blowing agent is injected into the nanocomposite in an extruder (a continuous mixer) or a batch mixer, polymeric foam can be produced. Supercritical carbon dioxide, an environmentally friendly, low-cost, non-flammable, chemically benign gas is used as the blowing agent. This process forms a microcellular foam with very high cell density (>10cells/cc) and small cell size (<5 microns) can be achieved by controlling the COcontent, melt and die temperature, and pressure drop rate. |
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