THE INFLUENCE OF MECHANICAL EFFECTS ON DEGRADATION OF POLYISOBUTYLENES AS DRAG REDUCING AGENTS

The mechanical degradation of high molecular weight polyisobutylene polymers (Oppanol B) wasstudied by exposing there dilute solutions to high speed mechanical stirring. Three Oppanol B,150, 200 and 250 types of molecular weight, 2.5, 4.1 and 5.9million g/mole were considered inpresent work. The shear viscosity of Oppanol B stock solutions of concentrations, 0.5, 1.0 and1.4w/v% was measured as function of exposure time.It was observed, that the degradation efficiency of higher molecular weight is larger than that oflower molecular weight in a whole polymer concentrations. The time dependence drag reductiondata was compared with the observation of shear degradation by stirring behavior. The decreaseof drag reduction with time is in evident to the mechanical degradation observed by shear stirringand viscosity decline of polymeric additives.