Intercalated Polymer Nanocomposites Prepared in Supercritical Carbon Dioxide

摘要

An alternative route to prepare polymer-clay nanocomposites using supercritical carbon dioxide (scCCy is described. The presence of clay nanoparticles significantly influences the morphology, foaming process and crystallization of a polymer when processed in scCO_2. Intercalated structures are successfully produced in the presence of scCO_2 even when favorable interactions between the polymer and the clay are not present. The effect of scCO_2 on the intercalation process is analyzed for a variety of polymer systems both with modified and unmodified clays. By controlling the hydrophilicity of the polymer and clay systems, specific understanding of the effect of scCO_2 on the structure and morphology of the nanocomposites is obtained. Experimental results show significant increases in the clays d-spacings for scCO_2-treated samples. This behavior is consistent regardless of the nature of the polymer, showing significant amounts of intercalation even in purely hydrophobic polymers.