Rheology associative thickeners

Glass, J.E., ed. "The Influence of Associative Thickeners and Rheology on Coatings Performance," 1983, Fargo, N.D. North Dakota State University Press. 

Figure 5.18 Storage and loss moduli for a 7% w/v HEUR associative thickener M — 33,100 Mu) Mn 1.47) end-capped with hexadecanol at 25°C. The lines are a fit to a one-mode Maxwell model. (From Annable et al. 1993, with permission from the Journal of Rheology.)...

Associative thickeners, such as PEG-55 propylene glycol oleate and PEG-120 methyl glucose dioleate, have been employed in shampoos to not only thicken but also introduce advantageous rheological properties [65,66], These materials... 

For more complex shampoos, including emulsions, a variety of thickeners is available besides salt, including gums, associative thickeners, synthetic polymers, and long-chain alcohols (Section II.C.2). These materials are used to attain a desired viscosity, to stabilize a product, and to attain a desirable rheological profile. Since they affect product structure, they can also affect lather. Viscosity modifiers, therefore, should be chosen to give the best mix of lather and rheological properties. 

Modification of poly(2-vinylpyridine) with a long-chain K-dodecyl bromide was the first published example of a polysoap in the literature [192]. (The term polysoap arises from the fact that the resulting modified polyelectrolyte displays similar properties to that of an ordinary soap [192,193].) Dependent on the aqueous solution conditions and the nature of the hydrophobe, modified polyelectrolytes can associate either intramolecularly or intermolecularly [194], and this has created interest from a technological perspective potential applications include use as associative thickeners and rheology modifiers [195]. 

DSIL [Henkel/G)atii% Chem.] Urethane associative thicken rheology modifier, thickener for paints, adhesives, coatings. 

Recently, a new class of surface-active synthetic WSPs called synthetic associative thickeners was introduced to the latex coatings industry. These compounds have generated interest because of their unique rheological characteristics in aqueous systems (i). These synthetic macromolecules are composed of hydrophilic and hydrophobic components. 

A few years ago, Landoll (2-4) reported that grafting a small amount of long-chain alkyl hydrophobes onto a nonionic water-soluble polymer leads to associative thickening behavior (i.e., enhanced viscosity, surface activity, and unusual rheological properties). This chapter deals with the general methods of preparation and solution properties of hydrophobically modified nonionic WSPs. Particularly described are the solution properties of hydrophobically modified (hydroxyethyl)cellulose (HMHEC) in aqueous and surfactant systems. 

HMHEC polymers are improved rheological modifiers for latex paints. They retain the benefits of traditional cellulosic ethers (compatibility with a wide range of coatings ingredients, storage stability, better sag resistance, etc.) but overcome many deficiencies of synthetic associative thickeners (sensitivity to latex systems and pH of paint formulations, poor sag resistance, etc.). The combined advantages offered by HMHEC are best suited for interior and exterior flat paints (5). 

Hydrophobically modified, ethoxylated urethanes (HEURs) are the thickeners of choice in exterior coatings and in corrosion-resistant, high-gloss industrial latex finishes. This chapter presents an overview of our research efforts and discusses approaches to the synthesis of HEUR polymers with different molecular architectures, geometrical influences on solution properties, and viable mechanisms by which this class of associative thickener effects desirable coatings rheology and applied film properties. 

The studies just discussed do not address one of the significant contributions associative thickeners make to coatings rheology minimizing LSVs in small-particle latex formulations. 

Optimizing Latex Paint Rheology with Associative Thickeners... 

Anwari Schwab Latex Paint Rheology b- Associative Thickeners 529... 

Anwari Schwab Latex Paint Rheology 6- Associative Thickeners 531... 

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