ids are organic solvents that are widely used to accommodate the film formation of waterborne coatings. The influence of the volatility, hydrophilicity, and amount of coalescing aids on the properties of waterborne dispersions and the dynamics of film formation was investigated. The results show that coalescing aids increased the viscosity through particle swelling and solvation, with the effect being stronger with more hydrophilic solvents. The results obtained with electrochemical impedance spectroscopy (EIS) and indentation tests show that hydrophilic coalescing aids were more efficient because of the partitioning on the particle interfaces but they could temporarily decrease the water resistance. The ease of coalescence was countered by solvent retention, which complicated the dynamics of film formation. EIS was used to optimize a real-world coating formulation and identify the pitfalls arising from the complex dynamics of film formation. The best resistance to humidity was obtained with a combination of hydrophobic and hydrophilic coalescing aids.
© 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45142.