Heat treatment-induced multiple melting behavior of carbon black-filled polymer blends in relation to the conductive performance stabilization

Polymer blend-based electrical conductive composites are provided with more possibilities for tailoring the performance in comparison with single polymer systems. To find an optimum heat treatment temperature of the composites, which is critical to practical applications, detailed thermal analyses of the related materials were carried out as a function of different annealing conditions. Based on the discussion of the morphological variation during treatment in terms of multiple melting behavior, it was found that an annealing temperature of 75 degreesC is able to stabilize the resistivity of the composites within a reasonable period of time, as only solid-state crystallization of LDPE and uniformization of EVA crystalline size are involved. In contrast to treatment at a temperature higher than 75 degreesC, the ultimate equilibrium resistivity resulting from the above annealing procedure approaches the resistivity of the composites as-manufactured, (C) 2001 John Wiley & Sons, Inc.