Detailed characterisation of heavy alkylated benzene fluids by multipulse one- and two-dimensional NMR spectroscopy

Abstract

In this paper, the results of a characterisation of heavy alkylated benzenes (HAB) using multipulse NMR spectroscopy are presented. Four commercial samples of heavy alkylated benzene have been characterised in detail in terms of various structural parameters, such as percentage aromatic carbon (Ca), degree of aromatic substitution, average alkyl chain length, type of alkyl chain and their proportions. Three of the HAB samples were very similar in structure, whereas, in the fourth, the structures present were entirely different. The latter had an abundance of 2-phenyl alkane-type structures, and did not contain methyl substituted tetralin or naphthalene type molecules. The influence of the structures on lubricating oil properties, including viscosity index, pour point, and viscosity, as well as FreonTM floc point, are also discussed.