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

• DOI: 10.1038/srep18624
• Publication Date: 2016-01-05T10:28:05Z
• Authors: Joshua W. Robinson; Yan Zhou; Priyanka Bhattach...; Robert Erck; Jun Qu; J. Timothy Bays; Lelia Cosimbescu
• Keywords: Viscosity index; Branching (polymer chemistry); Hildebrand solubility parameter; Polymer architecture

Abstract 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 beneficial and friction behavior when utilized an additive in a group I oil. The monomer was designed to undergo polymerization via polycondensation within architectural construct (AB 2 ), typical of hyperbranched polymers. design comprised aliphatic arms (12 or 16 methylenes) provide necessary lipophilicity achieve solubility non-polar medium. Once polymerized, catalyst heat, surface alcohols were functionalized with fatty acids (lauric palmitic). Controlling nature internal peripheral end-groups provided four unique flexible polymer designs. Changing reaction time concentration opportunities investigate influence molecular weight branching density on oil-solubility, friction. Oil-solubility found decrease fewer carbons, but number carbons appears have little bulk solution viscosity. At concentrations wt % base oil, these additives demonstrated improved reduced coefficient, validating basic approach.