Dynamic mechanical properties of short carbon fiber-filled styrene–isoprene–styrene block copolymer

The mechanical and dynamic mechanical properties of short carbon fiber-filled styrene–isoprene–styrene (S–I–S) block thermoplastic elastomeric composite have been studied. Brabender mixing followed by milling of the fiber–rubber compositions caused about a 30-fold decrease in the fiber aspect ratio and random fiber orientation. Although low-strain moduli increased on fiber incorporation, tensile and tear properties dropped and anisotropy in mechanical properties was not observed. Tan δ values at the T_g region decreased on filler incorporation, but at room temperature, the tan δ values increased with filler loading. The variation of storage moduli and tan δ values with frequency followed a pattern similar to the variation of these properties with filler incorporation. © 1993 John Wiley & Sons, Inc.