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Detailed characterisation of isomers present in polyalphaolefin dimer and the effect of isomeric distribution on bulk properties
Author(s) -
Scheuermann Sebastian S.,
Eibl Sebastian,
Bartl Peter
Publication year - 2011
Publication title -
lubrication science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.632
H-Index - 36
eISSN - 1557-6833
pISSN - 0954-0075
DOI - 10.1002/ls.151
Subject(s) - dimer , branching (polymer chemistry) , chemistry , homologous series , viscosity , vicinal , structural isomer , computational chemistry , organic chemistry , thermodynamics , physics
This study has been conducted with the aim to gain detailed insight into the chemical nature of polyalphaolefin dimer (PAO dimer, C 20 H 42 ). By using gas chromatography/mass spectrometry, a large number of isomers the complex mixture consists of has been identified; the variety of structural motifs ranges from a homologous series of almost linear vicinal dimethyloctadecanes to highly branched isomers such as 6,7‐dibutyldodecane. However, the mixture is characterised by the presence of isomers, which exhibit an intermediate degree of branching. Furthermore, a generally applicable protocol has been established to determine the relative content of these isomers. This protocol has then been applied to analyse samples from different PAO dimer batches, and a correlation between isomeric distribution and bulk properties, namely the viscosity–temperature behaviour, has been found. It turns out that the viscosity of PAO dimer depends less on temperature if the amount of weakly branched and almost linear isomers increases. Copyright © 2011 John Wiley & Sons, Ltd.