The behavior of polymers as viscosity index improvers

In the present work, six copolymers were prepared by reaction of 2-ethylhexyl methacrylate with vinyl acetate monomer by different molar ratio to produce copolymers (nu(1), nu(2), nu(3), nu(4), nu 5, and nu(6)). The composition of these copolymers were determined by molecular weight (using Gel Permeation Chromatography (GPC) Water 600 E.) and by (HNMR)-H-1 (by 300 MHz Spectrometer w-P-300, Bruker) which indicate that the copolymers are alternating copolymers with reactivity ratio of 2-ethyl hexyl methacrylate is 0.65 and vinyl acetate is 0.51. The efficiency of the prepared copolymers as viscosity index improvers for lube oil was studies. From the data obtained, it was found that the efficiency as viscosity index improvers increases by increasing the molecular weight of the prepared polymers and increasing the concentration of these copolymers. The data were discussed on light of the chemical structure and reactivity ratio of the prepared copolymers.