Estudo experimental da redução de arrasto por poliisobutileno e os efeitos da pré-diluição em solventes e degradação mecânica em escoamento turbulento

Abstract

This experimental project is an integral part of REAPA research line and aims to study the effects of pre-dilution of polyisobutylene (PIB) in organic solvents for the preparation of oily solutions, to characterize the rheological behavior of these solutions and to evaluate them regarding their drag reduction effectiveness and their mechanical degradation that these materials suffer in turbulent flow. Rheometric techniques of permanent and oscillatory shear regimes were used to evaluate the rheological behavior of high molecular weight PIB mixtures at different concentrations and to verify the impact of solvent use on the prior dispersion of these polymers. An experimental closed loop flow apparatus was used for the evaluation of the drag reduction capability of PIB additivated oily solutions and for the verification of turbulence-induced mechanical degradation effects. It was observed that the use of solvents in the pre-dispersion of the PIB did not significantly affect the density and shear viscosity while improving the preparation procedure. In the experimental circuit, it was noted that the molar mass significantly influences the drag reduction efficiency, while the degradation promotes the loss of efficiency until reaching a residual asymptote.