Effect of Heterogeneous Carbon Black Distribution on the Properties of Polymer Blends

Abstract

Abstract The results of this work support earlier findings regarding the transfer of carbon black in blends of BR with SBR, NR, and CIIR. Compared to conventionally-mixed compounds, in most cases vulcanizates with a heterogeneous carbon black distribution have superior hysteresis properties, presumably due to the presence of the unloaded layer mitigating the generally observed deleterious effects of carbon black upon these properties. The effect of unloaded SBR or BR layers on stress-strain values is quite small in SBR/BR blends where the zone size of the elastomer phases is small, but significant in SBR/NR and BR/NR where the zone size of the elastomer phases is larger. Superior cut growth resistance is seen for NR/BR and SBR/BR blends containing unloaded BR. The properties of SBR/BR and NR/BR blends in which most of the black is in the BR phase suggest that they may find utility in applications where superior hysteresis properties are required; e.g., in radial-tire sidewalls. Compounds with a heterogeneous carbon black distribution may also find utility in wire and cable applications, due to their superior insulating properties.