Izvorni znanstveni članak
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: 2.781 *