Rapid, Controlled Branching Polymerization of Cyanoacrylate via Pathway‐Enabled, Site‐Specific Branching Initiation

• Published in: Macromolecular rapid communications.
• Main Authors: Roxas, Alexander Perez, Yu, Han, Tamtaji, Mohsen, Yang, Zhenggen, Luo, Zhengtang
• Format: Journal Article
• Language: English
• Published: 08.11.2024
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.202400658

Abstract Controlled branched structures remain a key synthetic limitation for monomeric tissue adhesives because their on‐site polymerization that enables adhesion formation requires rapid kinetics, high conversion, and straightforward setup. In this context, site‐specific branching initiation by using evolmers is potentially effective for structural control; however, the efficiency and kinetics in current reaction setups persists to be a major challenge. In this paper, an evolmer induces a controlled branching polymerization of cyanoacrylate amid the high monomer reactivity useful in rapid adhesion. The contrasting reactivities between the vinyl and the initiating groups in the evolmer molecule generate a kinetic pathway that favors a control‐enabling branching mechanism. Through density functional theory calculations, the reaction pathway toward branching is shown to kinetically favor site‐specific initiation by six orders of magnitude than the route toward non‐specificity. Reaction monitoring confirms the branching polymerization after the polymerization with the evolmer forms a more compact structure than the linear counterpart. Control of branching density is demonstrated in rapid polymerizations within minutes and in polymerizations completed in an instant. These results provide a template for achieving site‐specific branching initiation during adhesion formation and, broadly, where conditions for kinetic control are necessary.