| abstract |
Polymeric compositions including PTC composites (99) that exhibit highly non-linear PTC effects together with extremely rapid, repeatable switching within a predetermined temperature range. In one embodiment, the polymer composite includes a polymer base material (102) with dispersed conductive particles that have very low densities and very low thermal conductivity properties. The conductive particles component can include hollow glass microsphere to provide low mass and low thermal conductivity properties together with a nanoscale conductive gladding or silver or gold. The conductive clad microspheres have a core portion (105) with a bulk density of less than about 2.0g/cm3 and a thermal conductivity of less than about 5.0 W/m-oK. |