From Architectures to Cutting-Edge Properties, the Blooming World of Hydrophobically Modified Ethoxylated Urethanes (HEURs)

Abstract

Hydrophobically modified ethoxylated urethanes (HEURs) are associative polymers that, compare to others, are far less sensitive to solution parameters, especially pH and ionic strength. Therefore, they are widely used as rheology modifiers in many different waterborne systems such as inks, coatings, emulsions, etc. In solutions, HEURs form transient networks through molecular associations between their hydrophobic groups. The transient network formation and its characteristics are responsible for the rheological properties and depend on the HEUR chains architecture. Many parameters such as molecular weight, size and nature of hydrophobic groups, polymer concentration, etc must be controlled to tune the several physicochemical properties of HEUR solutions. This article aims to give an overview of the HEUR studies reported in the literature in order to highlight the structure/rheological properties relationship. The article also draws attention to new trends in HEURs with innovative architectures and stimuli-responsive properties.

Brownian Dynamics Simulations of Telechelic Polymers Transitioning between Hydrophobic Surfaces

“…Telechelic rheology-modifying polymers have widespread applications in waterborne coatings (i.e., latex paints), pharmaceuticals, and personal care products. 1,2 The addition of rheology-modifying polymers to these formulations allows for tuning of their rheological profiles, such as controlling the zeroshear viscosity or increasing the control on the high-shear viscosity to make the coating easier to apply. 1 A common class of rheology-modifying polymers is hydrophobically modified ethoxylated urethanes, or HEURs, which consist of a hydrophilic polyethylene oxide (PEO) backbone and hydrophobic groups along the PEO backbone and/or end-capping the polymers.…”

Nonlinear Rheology of Telechelic Ionomers Based on Sodium Sulfonate and Carboxylate

“…Individual ionomer chains do not serve as independent network strands, as discussed for Figure . This result suggests that the transient network of the ionomers is similar to that in aqueous solutions of HEUR examined extensively. − ,− This HEUR network is schematically illustrated in Figure a for a case of all aggregates having similar size, and in Figure b for a more general case of the aggregates having a size distribution. Further detail of this structure is discussed in Section S5.3 in the Supporting Information.…”

Modeling of Branched Thickening Polymers under Poiseuille Flow Gives Clues as to How to Increase a Solvent’s Viscosity

“…The variables studied are the length of the polymers' branches, the strength of the bonds between monomers, the intensity of the angular interaction between neighboring bonds (which determine the flexibility of the polymers), and the polymer concentration. Our aim is to provide clues for the design and synthesis of optimal thickening molecules that can increase the viscosity of fluids such as CO2 for non-hydraulic fracturing [5], and aqueous complex fluids, such as paints [1]. This article is divided into four sections.…”

“…Research related to the design of new thickening additives that can increase the viscosity of fluids efficiently at a low concentration that are environmentally friendly and inexpensive is a topic of considerable current interest. These additives are used, for example, to increase the viscosity of different solvents such as water, to fine-tune the rheology of water-based paints, 1 or for supercritical CO 2 , which can be used as a water substitute in fracking and for enhanced oil recovery (EOR). 2−4 Thickening agents are typically polymers added to a fluid to increase its viscosity without changing the rest of its properties significantly.…”

“…Our aim is to provide clues for the design and synthesis of optimal thickening molecules that can increase the viscosity of fluids, such as CO 2 for nonhydraulic fracturing, 5 and aqueous complex fluids, such as paints. 1 This article is divided into four sections. After this Introduction, the DPD model, the simulation protocol, and its details are presented in the Models, Methods, and Simulation Details section, where the structure of the modeled polymers and their bonding and nonbonding interactions are also described.…”