Relation of free volume and barrier properties in the miscible blends of poly(vinyl alcohol) and nylon 6-clay nanocomposites film

A series of nylon 6-clay nanocomposite (NYC)/poly(vinyl alcohol) (PVA) blends films were prepared via melt compounding and pressing. The good compatibility between NYC and PVA was approved by DMA and FT-IR measurements. The macroscopic barrier properties of NYC/PVA blends films were inspected in detail, based on a microscopic free volume view of point. The gasoline permeation properties and the characterized parameters of free volume were adjusted through varying the PVA content. A similarity was found between barrier properties vs. PVA content and free volume parameters vs. PVA content. The relation between free volume fraction and permeability coefficient could be described exactly as an exponent function, implied that microscopic free volume plays an important role on determining macroscopic barrier properties.