Hydrophobically Modified Alkali Soluble Emulsion Polymers: Literature Review

Abstract

In recent years, interest in the class of water‐soluble polymers—hydrophobically modified alkali soluble emulsion (HASE)—has increased on a surprising scale. With respect to other associative polymers, they have several advantages in terms of cost and ease of handling and utilization. In addition, unlike the solvent‐based formulations, these water‐soluble systems do not contain volatile solvents and hence do not contribute to environmental problems. In solutions, HASE polymers form a transient network through molecular associations between the hydrophobic groups. Due to these hydrophobic interactions, they have been increasingly used as rheology modifiers for various applications, such as paints, cosmetics, and personal care and paper coating products. These associative polymers have an architectural richness that allows the fine tuning of several physicochemical properties, and their optimal use requires controlling polymer concentration, molecular weight, size of the hydrophobic groups, and characteristics of the polymeric backbone. We give an overview of several studies on HASE polymers reported in the literature, focusing on the molecular structure, the synthetic methodologies, and—more specifically—on the factors that affect the rheology of their aqueous mixtures. As a general rule for the optimal HASE design and formulative exploitation, we highlight that the hydrophobic hanging groups are responsible for the rheological changes in the liquid phase, while the steric hindrance of the polymeric backbone and of the hydrophobic groups causes the stiffness.

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

“…10 The hydrophobic groups can be randomly attached to the hydrophilic backbone, leading to comb-like polymers such as hydrophobically modified hydroxyethyl cellulose (HMHEC) 11 and hydrophobically modified alkali soluble emulsion (HASE). 3 The latter are composed of a negative polyelectrolyte backbone therefore, they are sensitive to pH and to the ions present in the solution. Despite their excellent flow properties, their use is limited to alkaline media.…”

“…Rheology control is a key point for many applications such as construction, cosmetics, coatings, and paints. − Its control over the entire life cycle of the product is essential to guarantee an optimal final application. To achieve this objective, rheology additives are used, representing a constantly growing market of $4.94 billion in 2015, which would reach $6.83 billion by 2024 .…”

“…Associative polymers are among the major rheology additives used in waterborne paints. − Their amphiphilic structure allows their solubility in water and the formation of a transient network thanks to interactions of their hydrophobic groups, either with emulsion particles or between themselves . The hydrophobic groups can be randomly attached to the hydrophilic backbone, leading to comblike polymers such as hydrophobically modified hydroxyethyl cellulose (HMHEC) and hydrophobically modified alkali soluble emulsion (HASE) . The latter are composed of a negative polyelectrolyte backbone; therefore, they are sensitive to pH and to the ions present in the solution.…”

Synthesis of new defoamer agents and characterization of cementitious formulations

“…Antifoams developed in recent years contain numerous components to satisfy different requirements. The active components can be classified based on their composition, in particular non-polar or polar components such as oil-based, silicon-based antifoams, and surfactants [ [16] , [17] , [18] ]. Antifoam agents act by replacing or modifying the active stabilizers on the surface; therefore, they must be more active on the surface.…”

In Situ Emulsion Polymerization to Multifunctional Polymer Nanocomposites: A Review

“…The nanoparticles were adapted under the CC BY license. [ 10 ] Coypright 2015,The Authors, published by MDPI.…”