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The effects of three molecular parameters on drag reduction were studied under turbulent-flow conditions. Drag reduction capability of linear polymers is altered by branching. Many short side chains decrease efficiency, while fewer but long branches increase it. The drag reduction of polyelectrolytes can be reversibly destroyed or enhanced by changes in configuration resulting from changes in pH or ionic strength or by complexing with counter-ion polyelectrolytes. Cross-linking can enhance or destroy the drag-reducing capability of a linear molecule, depending on the degree of cross-linking. Polymer degradation in turbulent flow is somewhat less in branched and cross-linked molecules than in linear ones.

Common methods of compounding elastomers involves the addition of solid ingredients to the elastomer on a mill or mixing all ingredients together in a Banbury mixer. Such methods are not appropriate when the ingredients are sensitive to heat and when the polymer will not band on a mill. Another method common to the art of compounding polymers is to dissolve the polymer in a solvent and add the other ingredients to form a suspension. The suspension is then mixed with a liquid in which neither the polymer nor the compounding ingredients are soluble. The present method, according to the patent, provides a means for compounding polymers which have reliable composition and homogeneity in the overall formulation.