||June 1, 2004
The Cabot Elastomer Composite process, a revolutionary mixing process proprietary to Cabot Corporation,is the first commercially successful process for latex-phase mixing of carbon black and natural rubber. It allows excellent dispersion of any carbon black type, at the microscopic and macroscopic level, with minimal reduction in the polymer molecular weight. In general, NR compounds mixed in the latex phase have result in better unaged and heat-aged performance over a range of compounds, compared to equivalent solid-phase mixed materials. This is due to differences in, molecular weight, and polymer-filler interaction achieved during the mixing process which results in a more thermally and mechanically stable compound. A formulation was prepared featuring 60 PHR N351 carbon black, using two different cure systems: conventional and reduced sulfur/accelerator. The samples were run through a battery of tests to compare physical and dynamic properties. The compounds prepared using the elastomer composite process gave improved aging properties, dynamic properties (including spring ratio) and improved flex life compared to the equivalent drymix compounds.