Differences in emulsion polymerization fouling between acrylates and vinyl acetate studied in-situ with a quartz crystal microbalance (QCM)

• Published in: Heat and mass transfer Vol. 61; no. 9
• Main Authors: Hoffmann, K. M., Langhoff, A., Adams, J., Huellemeier, H. A., Augustin, W., Scholl, S., Johannsmann, D.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2025; Springer Nature B.V
• Subjects: Acrylates; Continuous flow; Emulsion polymerization; Engineering; Engineering Thermodynamics; Fouling; Heat and Mass Transfer; Heat transfer; Industrial Chemistry/Chemical Engineering; Microbalances; Monitoring; Pressure drop; Quartz crystals; Thermal resistance; Thermodynamics; Thickness; Vinyl acetate
• ISSN: 0947-7411; 1432-1181
• DOI: 10.1007/s00231-025-03597-x

Fouling is a severe problem in emulsion polymerization, which – among other consequences – currently prevents polymerization in continuous flow reactors. Measuring the early stages of fouling (< 10 μm) can be challenging due to the low sensitivity of traditional fouling detection methods (i.e., thermal resistance and pressure drop). In comparison, measurements conducted with a highly sensitive quartz crystal microbalance enable the in-situ monitoring of fouling and the detection of the initial layers fouling. In this study, a QCM-D (quartz crystal microbalance with dissipation monitoring) was configured to function as a heat transfer surface to compare the fouling of acrylates and vinyl acetate. For the acrylates, fouling is self-limiting such that the layer thickness is finite and within the range of the diameter of acrylate particles. Thus, for acrylates fouling can be described as the adsorption of a single layer of particles. For vinyl acetate, the fouling layers grow continuously and result in a thick coagulum. The mechanistic details associated with the difference between acrylates and vinyl acetate is the subject of ongoing investigations. Furthermore, this work also explores how QCM-D technology can contribute to the study of fouling in general.