Process for making a high viscosity base oil with an improved viscosity index

A process to make base oil, comprising oligomerizing one or more olefins having a boiling point less than 82° C. (180° F.) in a presence of an ionic liquid catalyst and a mixture of C8+ alpha olefins derived from waste plastic to produce a base oil having a kinematic viscosity at 40° C. greater than 1100 mm2/s and a viscosity index (VI) greater than 55;

• wherein the ionic liquid catalyst is an alkyl substituted pyridinium chloroaluminate or an alkyl substituted imidazolium chloroaluminate of the general formulas A and B, respectively:
• where R, R1, R2, and R3 are methyl, ethyl, propyl, butyl, pentyl or hexyl, and X is a chloroaluminate.

A base oil, comprising one or more oligomers of a mixture of olefins, wherein the mixture of olefins comprises propylene and one or more C5+ olefins derived from waste plastic;

• wherein the base oil has a kinematic viscosity at 40° C. greater than 1100 mm2/s, and a viscosity index (VI) of at least 70;
• and wherein the ionic liquid catalyst is an alkyl substituted pyridinium chloroaluminate or an alkyl substituted imidazolium chloroaluminate of the general formulas A and B, respectively:
• where R, R1, R2, and R3 are methyl, ethyl, propyl, butyl, pentyl, or hexyl and X is a chloroaluminate.