MACROMOLECULAR CHEMISTRY AND POLYMERIC MATERIALS Antiturbulent Powers of Higher Polyolefins and Olefin Terpolymers

Terpolymers of ethylene with propylene and higher -olefins with various compositions and molecular weights were synthesized, as well as copolymers with higher poly- -olefins with various molecular weights. The possibility of laboratory assessment of the antiturbulent power of polymers and turborheometric determination of the volumes and molecular weights of poly- -olefin macromolecules was examined. Introduction of polymer additives to a turbulent flow of a liquid increases its viscosity but decreases the hydrodynamic resistance coefficient and, thus, in- creases the average flow rate or decreases the friction loss of the pressure (Toms effect (1)). The mechanism of this somewhat unusual phe- nomenon remains the subject of heated discussions, but the ability of polymers to decrease the turbulent flow resistance has found wide application, in par- ticular, in oil and oil product transportation via pipe- lines (2, 3). By now, hydrodynamic properties of a large num- ber of polymer samples of different chemical nature have been studied. It was found that many of them exhibit the Toms effect (4) under laboratory condi- tions, but only a few proved to be suitable for and demanded by commercial oil and oil product pipe- lines. The divergence between the results of laboratory and field experiments can be explained in part as fol- lows. The Toms effect, %, is quantitatively described by the formula DR =( s p )/ s 100, (1)