Influence of the association of hydrophobic end groups on the temperature insensitivity of HEUR-thickened latex/Fe2O3/Zn3(PO4)2</ sub>/BaSO4 suspensions

作者：Lin, Yating; Song, Chunmei^*; Xiao, Xiong; Wan, Bo

来源：Journal of Coatings Technology Research, 2023, 20(2): 587-601.

DOI：10.1007/s11998-022-00692-0

• Hydrophobically modified ethoxylated urethanes
• Temperature insensitivity
• Thixotropy
• Elastic fluid
• Association

Hydrophobically modified ethoxylated urethane (HEUR) with different structures was synthesized and confirmed by gel permeation chromatography, Fourier transform infrared spectroscopy and nuclear magnetic resonance (H-1 NMR). We propose the relationship between the temperature insensitivity model and the thickening mechanism of HEUR/latex/Fe2O3/Zn-3(PO4)(2)/BaSO4 suspensions. Meanwhile, the temperature insensitivity of HEUR/C suspensions is the result of two main associations: intermolecular interactions bridging the hydrophobic tails of HEURs and the hydrophobic groups tightly adsorbing onto the latex particle surfaces. A smaller ratio of viscosity (Rv) at 1 s(-1) from the steady state condition indicates the better temperature insensitivity of viscosity. The higher degree of crystallinity and rheological activation energy corresponds to a great extent with better temperature insensitivity due to stronger association. The temperature insensitivity is consistent with the longer hydrophobic chain, which was proven by hysteresis tests and oscillatory shear measurements. The storage stability was enhanced in the lockstep with a hydrophobic length of HEUR, which is consistent with the rougher surfaces of HEUR/C films As an appealing method, the results are meaningful and instructive for coating storage and application. @@@ [GRAPHICS] @@@ .