Calcium carbonate treated with an interfacial agent such as stearic acid or a stearate is often used in place of untreated calcium carbonate to take advantage of improved lubricity and wetting characteristics. These characteristics typically lead to lower mixing viscosity, improved filler dispersion and better flow properties.
In this paper, the effect of fatty acid derivatives on polypropylene compounds highly filled with calcium carbonate, both treated and untreated, is discussed. The use of fatty acid derivatives can be effective for lowering extrusion pressure leading to throughput increases. The overall effect on filler addition, viscosity, mixing and processing properties will be shown for one class of fatty acid derivatives.