Study of the influence of some polymeric additives as viscosity index improvers and pour point depressants – Synthesis and characterization

• Multifunctional acrylate based polymeric additives for lubricating oil.
• Branching in the acrylate chain showed better additive performance.
• Linear acrylates are thermally stable compared to branched acrylates.
• VI increased with the increase in additive concentration in lube oil.
• Polymer solvent interaction is more prominent in case of branched acrylate polymers.

Homopolymers of decyl acrylate and isooctyl acrylate and copolymers of each of them with 1-decene were synthesized and characterized by viscosity measurement, thermogravimetric and spectral analysis. Viscometric methods were used to determine the intrinsic viscosity of each of them. Pour point depressant (PPD) and viscosity index improver (VII) properties were tested with additive doped base oil in terms of pour point (PP) and viscosity index (VI), respectively. Although the decyl acrylate polymers were thermally more stable than the isooctyl acrylate polymers, the latter showed higher VI and pour point depression efficiency. VI and PP values of the additive doped base oils depend on the nature of mineral base oils as well as on the type and concentration of VI improvers.