Precision Synthesis of End-Functionalized Star Poly(vinyl alcohol)s by RAFT Polymerization and Post-polymerization Modification

Poly(vinyl alcohol) (PVA) has been widely used in industrial and consumer products. In this study, we aimed to address this challenge by synthesizing well-defined multiarm poly(vinyl acetate) (PVAc) through the use of nonhydrolyzable vinyl ether-type multifunctional RAFT agents. The control over molecular weights was achieved by the RAFT process to afford polymers with dominant head-to-head linkages at the terminal. Especially, quantitative end-functionalization of the synthesized PVAc was performed using Michael thiol–ene or disulfide exchange reactions. Consequently, saponification of the PVAc enabled the synthesis of end-functionalized multiarm PVA in an efficient manner. This straightforward approach afforded well-defined functional PVAs, which enable further chemical modification, thus widening the utility of PVA in a range of applications, such as precisely controlled network synthesis and bioconjugation.