Dynamics of supramolecular associative polymer networks at the interplay of chain entanglement, transient chain association, and chain‐sticker clustering

• Published in: Journal of polymer science. Part B, Polymer physics Polymer physics, 2019-09, Vol.57 (18), p.1209-1223
• Main Authors: Jangizehi, Amir, Ahmadi, Mostafa, Seiffert, Sebastian
• Format: Article
• Language: English
• Subjects: Chain entanglement; Clustering; Dynamic mechanical properties; Entanglement; Group theory; Mechanical properties; Networks; Organic chemistry; phase separation; Polymers; Rheological properties; Rheology; supramolecular structures; viscoelastic properties
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.24782

ABSTRACT The dynamic mechanical properties of supramolecular associative polymer networks depend on the average number of entanglements along the network‐forming chains, Ne, and on their content of associative groups, f. In addition, there may be further influence by aggregation of the associative groups into clusters, which, in turn, is influenced by the chemical structure of these groups, and again by Ne and f of the polymer. Therefore, the effects of these parameters are interdependent. To conceptually understand this interdependency, we study model networks in which (a) Ne, (b) f, and (c) the chemical structure of the associative groups are varied systematically. Each network is probed by rheology. The clustering of the associative groups is assessed by analyzing the rheological data at the end range of frequency covered and by comparison of the number of supramolecular network junctions with the maximum possible number of binary transient bonds. We find that if the total number of the network junctions, which can be formed either by interchain entanglement or by interchain transient associations, is greater than a threshold of 13, then the likelihood of cluster formation is high and the dynamics of supramolecular associative polymer networks is mainly controlled by this phenomenon. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1209–1223 Supramolecular associative polymer networks consist of (macro)molecular building blocks associated by physical transient bonds. To engineer such materials in a rational fashion, quantitative conceptual knowledge about the underlaying supramolecular‐associative polymer‐network dynamics and mechanics is crucial. In this article, the interplay of interchain entanglement, interchain transient association, and aggregation of the associative groups into clusters and their effects on the dynamic mechanics of a library of supramolecular associative polymer networks are studied. These three parameters are interdependent, and the latter is further influenced by the chemical structure of the associative groups.