Joule heating treatments of conductive butyl rubber/ceramic superconductorcomposites: a new way for improving the stability and reproducibility?

The present paper describes the effect of superconductors on the sintering process, apparent cross-linking density, sintering factor, hardness and vol ume fraction of butyl rubber (IIR) composites. Electrical conductivity and I-V characteristics at various processing conditions of IIR with different concentrations of superconductor were measured. The stability and reproduci bility of IIR composites were tested. Also, the conduction mechanism of ele ctrical conductivity is discussed. Specific heat and the amount of heat tra nsferred by radiation and convection were calculated via the proposed model and calorimetry as a function of superconductor content. It was found that superconductor accelerates the driving force during the sintering process and the characteristic time constant during sintering decreases while the s intering factor, the apparent cross-linking density, hardness and volume fr action of rubber increases as the content of superconductor increases. In a ddition, it was proved that the superconductor and Joule heating effect imp roves the electrical and thermal properties of IIR. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.