Abstract
Water vapor permeability (WVP) and CO2 permeability (CDP) are important properties of modern architectural coatings for the protection of building materials such as concrete. A cup method and a high vacuum method were employed to measure the WVP and the CDP, respectively, for three sets of acrylic latex films which were prepared by either single-stage or two-stage emulsion polymerization. For a set of model latex films comprising different combinations of main and auxiliary monomers, it was found that the monomer composition significantly affected the WVP and the CDP. The WVP and the CDP results were explained in terms of the stiffness of polymer chain segments, the crystallinity, and the polarity of the latex films. Compared with the model latex films of a simple core structure containing butylacrylate as a main monomer, the control film of core/shell structure of similar composition showed desirable permeability properties of higher WVP and lower CDP. There was a rough trend of trade-off between the WVP and the CDP of the latex films. Among the model latex films, those containing ethylacrylate monomer showed relatively better behaviors for both the WVP and the CDP. For the other two sets of hard and soft latex films, the WVP for both sets significantly increased with increasing content of hydrophilic microgel particles. As the amount of microgel increased, the CDP for soft latex films was reduced, whereas that for hard latex films slightly increased.
Original language | English |
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Pages (from-to) | 380-388 |
Number of pages | 9 |
Journal | Journal of Industrial and Engineering Chemistry |
Volume | 7 |
Issue number | 6 |
State | Published - 2001 |
Keywords
- Acrylic latex films
- CO permeability
- Protective coatings
- Water vapor permeability