Polymer compositions exhibiting a PTC property and methods of fabrication

A conductive polymer composition exhibiting a positive temperature coefficient (PTC) property, the composition comprising:

• a matrix comprising at least one polymer component;
• and
• a plurality of conductively clad glass microspheres dispersed within the at least one polymer component, each condictively clad glass microsphere comprising an electrically conductive cladding over a core portion, wherein a plurality of core portions has a mean thermal conductivity of less than about 5.0 W/m.-° K.

A conductive polymer composition exhibiting a PTC property, the composition comprising:

• a matrix comprising at least one polymer component comprising at least one of polyethylene, polyamide, polystyrene, polyacrylonitrile, polyethylene oxide, polyacetal, thermoplastic modified cellulose, polysulfone, thermoplastic polyester, poly(ethyl acrylate), poly(methyl methacrylate), nylon, polyvinylidene fluoride or ethylene tetrafluoroethylene;
• and
• a plurality of conductively clad elements dispersed within the at least one polymer component, the plurality of elements comprising at least about 20% by volume of the composition, each element comprising an electrically conductive cladding portion over a core portion, wherein the plurality of core portions has a bulk density of less than about 2.0 g/cm3 and the cladding portion comprises at least one of silver, gold, platinum, nickel, tin, copper, palladium, magnesium, aluminum, iron, molybdenum, tungsten, tantalum, zirconium, zinc, cobalt, chromium or carbon.