Abstract:
Butyl rubber–Ba(Zn1/3Ta2/3)O3 (BR–BZT)
composites and butyl rubber–silica (BRS) composites were
prepared by sigma mixing. The dielectric properties at
1 MHz and 5 GHz of BR–BZT and BRS composites were
investigated as a function of ceramic loading and were
found to be improved with filler loading. For a optimum
BZT loading of 0.26 vf, the BR–BZT composite have
er = 4.88, tand = 0.0022 (at 5 GHz), coefficient of thermal
expansion (CTE) = 112 ppm/ C, thermal conductivity
(TC) = 0.30 Wm-1 K-1 and water absorption = 0.047
vol%. The BRS composites attained er = 2.79, tand =
0.0039 (at 5 GHz), CTE = 102 ppm/ C, TC = 0.40
Wm-1 K-1 and water absorption = 0.078 vol% for the
same loading of silica. The stress–strain curves of both
composites showed good flexibility of the composite. The
measured relative permittivity and TC of both composites
were compared with different theoretical approaches.
