Thermal conductivity of ethylene vinyl acetate copolymer/nanofiller blends

To reduce weight and increase mobility, comfort, and performance of future spacesuits, flexible, thermally conductive fabrics and plastic tubes are needed for the Liquid Cooling and Ventilation Garment. As an approach to raise thermal conductivity (TC) of an ethylene vinyl acetate copolymer (Elvax™ 260), it was compounded with carbon based nanofillers: multi-walled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNFs), and expanded graphite (EG) as well as metallized CNFs, nickel nanostrands, boron nitride, and powdered aluminum. Ribbons and tubing of the nanocomposites, in which the nanofillers were aligned in the direction of flow, were extruded. Compression molding was used to fabricate nanocomposites in which the nanofillers were randomly oriented. TC of the samples was measured in the direction of, and perpendicular to, the alignment direction and significant improvement in TC (up to 24-fold) was observed when measurements were made in the direction of alignment.