Physical Sciences and Mathematics Commons^™

Rheological Studies Of Fully-Formulated Coatings Thickened With Heur: Effects Of Surfactants, Brandon M. Bonilla

Master's Theses

Rheology modifiers such as hydrophobically-modified ethoxylated urethane (HEUR)thickeners are included in waterborne latex coatings to optimize shear-rate dependent viscosity and other rheological properties. While these HEUR polymers are commonly used in industry, the complex chemical interactions that contribute to rheological properties are still not completely understood. Prior work in this area has focused on understanding latex-HEUR and latex-surfactant-HEUR interactions that affect rheological properties. Additionally, studies have been previously conducted to understand the relaxation mechanisms of complex interactions present in HEUR-thickened waterborne latex coatings under various dynamic conditions. The objective of this work is to extend the experimental work to fully-formulated …

Rheological Investigations Of Latex-Surfactant-Associative Thickener Aqueous Systems, Bishop I. Hammack

Master's Theses

Surfactants and Thickeners are both additives used in fully-formulated waterborne coatings to provide colloidal stability, thickening, and other functionality. The behavior of each ingredient in a coating must be understood and controlled to maintain colloidal stability as well as balance other desired properties of the liquid coating and the dry paint film. In this work, quaternary systems of Water-Latex-Thickener-Surfactant were investigated to further the understanding of their behavior in coatings. The thickener used was a well characterized, hydrophobically-modified, ethoxylated urethane (HEUR) with two C18 terminal hydrophobes and 795 average repeat units of ethylene oxide as the hydrophilic spacer. Two latexes, …

Phase Behavior And Rheology Of Latex, Thickener, Surfactant Mixtures And Liquid Crystal Based Compositions For Printing High-Efficiency Flexible Electronics, Franceska Anna Santos

Master's Theses

This project consists of two parts. One area of focus in the first part is understanding the interactions between a non-ionic, block copolymer type dispersant and hydrophobically-modified, ethoxylated urethane (HEUR) associative thickeners in water. The dispersant was mixed at various concentrations (0-2% by weight) with HEUR thickeners at 1% by weight concentration in the aqueous medium. This study is an integral part of our attempts to determine mechanisms of viscosity drop when colorant dispersions are added to latex tint base formulations thickened with associative thickeners. One of the HEUR thickeners is a product that has been available for over three …

The Effects Of Color Concentrates On The Rheology Of Tint Bases, Doug James Herrick

Master's Theses

ABSTRACT

THE EFFECTS OF COLOR CONCENTRATES ON THE RHEOLOGY OF TINT BASES

Douglas James Herrick

Waterborne coatings are formulated with a number of different ingredients; water, latex polymers, pigments, surfactants, dispersants, defoamers, biocides, coalescing aids, and rheology modifiers or thickeners. Rheology modifiers are necessary in order to improve the physical properties of the coating before, during, and after application to a substrate. There are two kinds of rheology modifiers used in waterborne coatings; associative thickeners and non-associative thickeners. Coatings formulated with associative thickeners are quite sensitive to coating variations; the slightest change in the formulation has profound effects on the …