Synthesis and Development of Novel Copolymer Additives for Enhancing Viscosity Index and Pour Point of Medium Viscosity Iraqi Lubricating Oil

Abstract

Four novel copolymers (HT, TT, OT, and DT) were synthesized through free radical polymerization by reacting various alkyl chain-length acrylate with 1-tetradecene. The structural characterization of these copolymers was achieved by determining their molecular weights using Gel Permeation Chromatography (GPC), analyzing their chemical structure with Fourier Transform Infrared spectroscopy (FTIR), and examining their composition through Proton Nuclear Magnetic Resonance (1H-NMR) spectroscopy. thermogravimetric analysis (TGA) was also employed to assess thermal stability. The copolymers were evaluated for their effectiveness as additives to enhance the viscosity index and pour point of medium viscosity Iraqi lubricating oil (base oils 60). The results indicated that the efficiency of new copolymers as viscosity index improvers increased by an increase in concentration and alkyl chain lengths in the acrylate components. All new copolymers achieved good results compared to free additives lubricating oil, but the copolymer (DT) achieved the best efficiency (VI= 170 ) at (5% wt.) concentration compared to free additives lubricating oil (VI = 98 ). On the other hand, the efficiency of copolymers as a pour point depressant increased by decreasing the concentration and alkyl chain length; the copolymer (HT) achieved the best efficiency (PPD = -20oC) compared to free additives lubricating oil (PPD = -5 oC).
Keywords: Viscosity index improvers; alkyl acrylate; pour point