engleski

The Low Temperature Flow Improvers for Lubricating Oil Based on Styrene and Alkyl Methacrylate Copolymers

Mineral lubricating oils contains paraffin wax, which at lower temperatures, crystallizes, gels and prevents free flow of the oil, thereby giving high pour point values. Some polymers of particular structure act as pour point depressants preventing congealing of wax at lower temperatures and offer effective and economically attractive alternative to entirely removing wax from oils by dewaxing. This paper described low temperature behavior of lubricating mineral oil pour point depressants on the base on synthesized methyl/dodecyl/octadecyl-methacrylate terpolymers (PAMA), styrene/methacrylate terpolymers (PAMA-S) as well as their mixtures with mostly used viscosity index improver poly(ethylene-co-propylene) (OCP). The pour point temperatures were determined and the melting transitions and heats of fusion for the crystalline phase of terpolymer depressants were examined by differential scanning calorimetry to elucidate the mechanism of their action. It was proved that the best low temperature properties in investigated paraffinic base oil give a proper ratio of the long side chain n-alkyl methacrylate groups. As far as PAMA-S is concerned, it was established that increased styrene content causes pour point to rise, while this increase may be divided in two linearly dependent areas.

lubricants; low temperature flow improvers; copolymers

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