Abstract
A B-type Banbury mixer was operated to mix SBR (#1500) with carbon black (Vulcan-6, Sterling-L) in full capacity (1l) at a fixed rotational velocity (60rpm).
By analyzing the characteristic dependence of input on time, which would reflect the change in mixedness of the sample during the mixing, four typical stages of mixing process were found to exist. A qualitative discussion was given to the influence of the particle size of fillers on the lifetimes of those mixing stages.
The mixtures obtained at various lengths of mixing time were tested in a Mooney viscometer, and the data were then analyzed in terms of the method given in the previous report. The degradation in the molecular weight of SBR during the mixing was estimated from the values of ML∞ for those mixtures with the information on the molecular weight- and the filler content-dependences of ML∞ obtained previously.
