High performance blends and composites: Part (I) clay aerogel/polymer composites. Part (II) mechanistic investigation of color generation in PET/MXD6 barrier blends

High performance in polymer blends and composites can be achieved through the addition of a strong filler component into a polymer matrix. The overall physical and chemical properties of a composite are determined in large part by the interaction of this filler component with the matrix.; Low density polymer composites have been prepared using clay aerogels. The structure of clay aerogels can be modified by varying either the process conditions or by electrolyte addition during its preparation. By such process changes, the overall structure and density of the resulting composites can be controlled. Clay aerogel imparts thermal, mechanical and structural stability to the composites.; Enhanced oxygen barrier (∼3X) in blends was achieved by addition of kinked molecule of poly(m-xylylene adipamide) MXD6 into a poly(ethylene terephthalate), PET, matrix. The resulting blend is optimized for its optical and chemical properties. Transparency of these blends was improved by reducing the refractive index mismatch in the stretch direction through the addition of high refractive index co-polyamides. PET, when melt processed with MXD6, results in a chemical reaction which generates color; the structure of the resulting conjugated chromophore is mechanistically determined through the investigation of model compounds. Color is thus eliminated in the blends by reducing the conjugated chromophore.