Organocatalytic cationic degenerate chain transfer polymerization of vinyl ethers with excellent temporal control

Abstract

An organocatalytic cationic degenerate chain transfer (DCT) polymerization of vinyl ethers with temporal control under visible light is reported. By using a bisphosphonium salt (BPS) as the photocatalyst and easily prepared thioacetal as the chain transfer agent, well-defined and colorless poly(vinyl ether)s with good molecular weight control and narrow molecular weight distributions can be obtained. The resulting polymers exhibited high chain-end fidelity, allowing further in situ chain extension and chain-end functionalization to synthesize block copolymers and end-functionalized polymers. Notably, the excellent stability and efficiency of BPS enables a strict temporal control over polymer chain growth at high monomer conversion for a long dark period.