Detailed characterisation of polyalphaolefins and their branched structures using multi‐pulse NMR techniques

The present work describes some structural investigations carried out on commercial and laboratory synthesised polyalphaolefin (PAO) samples. A number of structures having different branched groups along the chain have been identified in the hydrogenated dimer product of 1‐decene, using multi‐pulse 13C‐NMR DEPT techniques. These branched structures have been further confirmed by correlating methyl and methine group resonance in the 13C‐NMR spectra, using a CALMOD computer program. An insight into the molecular mobility and dynamics of various structures has been obtained through spin lattice relaxation measurement. The study aims to provide a better understanding of the structure—performance relationships in PAOs. A probable mechanism of oligomerisation responsible for the formation of the identified structures is proposed.