Preparation Of Hydrophobically Modified Ethoxylate Urethane Thickener And Its Application In Latex Paint

Latex paint thickener is a kind of rheological additive which plays an important role in storage and construction of paints. Its development experienced from the early inorganic thickener to synthesized organic thickener, and from cellulose to alkali soluble acrylic thickener(ASE) then to polyurethane associative thickener. Hydrophobically modified ethoxylate urethane thickener(HEUR), for its surfactant-like performance in aqueous solution and unique thickening property, is distinguished from other types of thickeners with high viscosity under high shear rate. Therefore, it is more likely to be used in high-grade coatings which require higher level of the levelling performance. Nowadays, people's requirement for―low-carbon‖life stimulates the development of latex coatings as well as the thickeners.This paper mainly includes synthesizing series of polyurethane associative thickeners, and exploring the differences by applying different hydrophobic and hydrophilic segments or different molecular weight. The most efficient match was proposed based on above research.In order to simplify the preparation process and improve productivity, synthesis of HEUR thickener was performed in a kind of water-soluble and low-toxic solvent. The thickening effects proved to be no difference with samples prepared by traditional process.Synthesizing a kind of star-like structure HEUR, and study of it was operated in latex paint by comparing it with linear-chain HEUR.Applications of different kinds of thickeners were also discussed in this study. Properties like changes of grain diameters,―water-separation‖phenomenon,―post-thickening‖phenomenon were studied in latex systems with CMC ASE HEUR added separately. And with these comparison, their advantages and disadvantages were displayed clearly and effectively.