Probing the molecular design of hyper-branched aryl polyesters towards lubricant applications

Journal Article · Tue Jan 05 00:00:00 EST 2016 · Scientific Reports

DOI:https://doi.org/10.1038/srep18624· OSTI ID:1330856

Robinson, Joshua W.; Zhou, Yan; Bhattacharya, Priyanka; Erck, Robert; Qu, Jun; Bays, J. Timothy; Cosimbescu, Lelia

We report novel polymeric materials that may be used as viscosity index improvers (VII) for lubricant applications. Our efforts included probing the comb-burst hyper-branched aryl polyester architecture for beneficial viscosity and friction behavior when utilized as an additive in a group I oil. The monomer was designed as to undergo polymerization via polycondensation within the architectural construct (AB2), typical of hyperbranched polymers. The monomer design was comprised of aliphatic arms (12 or 16 methylenes) to provide the necessary lipophilicity to achieve solubility in a non-polar medium. Once polymerized, via catalyst and heat, the surface alcohols were functionalized with fatty acids (lauric and palmitic). Controlling the aliphatic nature of the internal arms and peripheral end-groups provided four unique flexible polymer designs. Changing the reaction time and concentration provided opportunities to investigate the influence of molecular weight and branching density on oil-solubility, viscosity, and friction. Oil-solubility was found to decrease with fewer internal carbons, but the number of internal carbons appears to have little influence on the bulk solution viscosity. At concentrations of 2 wt % in a group I base oil, these polymer additives demonstrated an improved viscosity index and reduced friction coefficient, validating the basic approach.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE) - Office of FreedomCar and Vehicle Technologies; USDOE Office of Science - Office of Basic Energy Sciences - Scientific User Facilities Division
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1330856
• Journal Information: Scientific Reports, Vol. 6, Issue 1; ISSN 2045-2322
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English