Influence of Delayed, Ionic Polymer Cross-Linking on Film Formation Kinetics of Waterborne Adhesives
The impact of ionic polymer cross-linking on the film formation kinetics of waterborne dispersions designed for use as acrylic pressure-sensitive adhesives (PSAs) was studied with Förster resonance energy transfer (FRET). Aluminum acetylacetonate (Al(acac)3) was added as an ionic cross-linker to a...
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Published in | Macromolecules Vol. 52; no. 1; pp. 271 - 280 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
American Chemical Society
08.01.2019
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Online Access | Get full text |
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Summary: | The impact of ionic polymer cross-linking on the film formation kinetics of waterborne dispersions designed for use as acrylic pressure-sensitive adhesives (PSAs) was studied with Förster resonance energy transfer (FRET). Aluminum acetylacetonate (Al(acac)3) was added as an ionic cross-linker to a latex with un-cross-linked chains. The polymer interdiffusion (studied with FRET) suggests that the degree of polymer cross-linking in the wet dispersion is small, as the interdiffusion kinetics is similar to that of a latex with un-cross-linked chains only. Cross-linking mainly takes place when the film dries, and it is slower than interdiffusion; thus, a homogeneous film can be formed. Ionic cross-linking in the final film through Al3+ was proven by a large gel content and an increased cohesion, the latter evaluated with tensile and tack tests. Further aspects studied include the influence of serum pH on interdiffusion and cross-linking reaction and how ionic cross-linking before film formation affects interdiffusion. |
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ISSN: | 0024-9297 1520-5835 |
DOI: | 10.1021/acs.macromol.8b01870 |