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LUBRICATING OILS POUR POINT DEPRESSANTS BASED ON ALKYL METHACRYLATE AND STYRENE COPOLYMERS
Zvonimir Janović
Ante Jukić
Evira Vidović
Jakov Romano
Ankica Barišić
Meri Picek
Sažetak
Abstract
The paper describes low-temperature properties of mineral lubricating oils with polymeric additives based on terpolymers of styrene with dodecyl methacrylate and octadecyl-methacrylate (PAMA-S). The obtained results were compared with the efficiency of conventional additives based on long-chained methacrylates. The composition and structural properties of terpolymers were determined using the methods of NMR and size exclusion chromatography (SEC). By increasing styrene content in terpolymer, there occurs a gradual increase of the lubricating oil pour point values, from -33 °C for a 5 wt. % styrene content to -27 °C for a 15 wt. % styrene content, and then, for higher styrene values, up to the lubricating oil pour point value of -9 °C. The additive activity mechanism was established based on the pour point values of terpolymer oil solutions, as well as the specific thermal terpolymer values: glass transition temperature, melting point, melting enthalpy and crystal phase content – obtained by the method of differential scanning calorimetry. Confirmed was the mechanism of pour point reduction through the co-crystalization of long-chained n-alkyl groups of methacrylate polymers and n-paraffinic base oil hydrocarbons. Optimal low-temperature properties of PAMA-S are obtained by a proper composition and ratio of the long-chained alkylate groups, in compliance with the composition of base oil paraffinic hydrocarbons.
Ključne riječi
paraffine interaction with pour point depressant; polyalkylmetacryilate VI improver (PAMA); octadecilmetacrylate (ODMA); size exclusion chromatography (SEC); relation of crystal structure and properties; relation of amorfphous and crystalline state
Hrčak ID:
6583
URI
Datum izdavanja:
30.6.2006.
Posjeta: 2.141 *