Superbase-enabled anionic polymerization of poly(alkyl cyanoacrylate)s:achieving well-defined structures and controlled molar masses

Poly(alkyl cyanoacrylate)s (PACAs) find extensive use as adhesives in engineering and medicine. However, their high reactivity often leads to wide molar mass dispersity and uncontrolled chain-end functionalities. Achieving precise polymer structures is crucial, particularly for medical applications to prevent oligomer toxicity. The conventional anionic polymerization of cyanoacrylates initiated by water results in high molar mass dispersities (Ð) and low end-group functionalities. Nonetheless, under specific conditions, anionic polymerization holds the potential for controlling the molar mass and Ð of PACAs. Here, we demonstrate the synthesis of well-defined PACAs by employing minute quantities (1%) of superbases to activate a functional thiophenol (PhSH) initiator. This strategy enables the attainment of adjustable molecular weights (Mn &gt; 20 kg mol−1) and moderate dispersities (Ð &lt; 1.4) for homopolymers and block copolymers. The selective initiation by thiophenol is confirmed through 1H DOSY NMR analysis. Furthermore, the controlled homo- and copolymerization of ACA derivatives highlights the remarkable performance of the superbase in conjunction with PhSH.</p