Polymethacrylates: Pour point depressants in diesel oil

A variety of techniques have been employed in order to reduce problems caused by the crystallization of paraffin during the production and/or transportation of paraffin oils and derivatives. Methacrylate copolymers are known as additives which reduce the pour point of these oils. This paper describes the synthesis, characterization and performance evaluation of these copolymers, having as an initial step the synthesis of the alkyl methacrylate monomers by transesterification of methyl methacrylate (MMA) with C₁₄, C₁₆ and C₁₈ fatty alcohols. The copolymerization of these monomers with MMA was then performed, with molar ratios of 30:70, 50:50 and 70:30 for alkyl methacrylate:methyl methacrylate. All products were characterized by FTIR, ¹H NMR and gel permeation chromatography (GPC). All the methacrylic copolymers lead to a large reduction in the pour point of samples of Brazilian diesel oil. Oil samples containing 50 ppm of the polymeric additive with ca. 70% octadecyl methacrylate units showed a 22 °C reduction in their pour points, thus establishing the large efficiency of the products synthesized in this work.