Copolymers as flow improvers for Mexican crude oils

A series of copolymers derived from styrene (S), n-butyl acrylate (BuA), and vinyl acetate (VA) monomers were prepared by emulsion polymerization to improve some physical properties of Mexican crude oils (MCOs). Once obtained, the copolymers were characterized by Fourier transform infrared (FTIR) spectroscopy, size-exclusion chromatography (SEC), and thermogravimetric analysis (TGA). Later, they were dissolved in toluene and were added to both light and heavy MCOs; the pour point temperature and apparent viscosity of these mixtures were carefully evaluated. Results indicate that styrene and vinyl acetate (SVA) copolymers show a good pour point depressant performance for both types of crude oils. The apparent viscosity dependence on temperature for light and heavy crude oils, mixed with copolymers, was also established. It was observed that, in general, the addition of copolymers decreases the apparent viscosity of both light and heavy crude oils above 35 °C.