Oxygen‐Tolerant Photochemically Induced Atom Transfer Radical Polymerization of the Renewable Monomer Tulipalin A

• Published in: ChemPhotoChem 2019-11, Vol.3 (11), p.1138-1145
• Main Authors: Zain, Gamal, Bondarev, Dmitrij, Doháňošová, Jana, Mosnáček, Jaroslav
• Format: Article
• Language: English
• Subjects: block copolymers; controlled radical polymerization; functional polymers; photopolymerization; sustainable chemistry
• ISSN: 2367-0932; 2367-0932
• DOI: 10.1002/cptc.201900151

Well defined homopolymers and block copolymers from renewable monomer α‐methylene‐γ‐butyrolactone (MBL) were prepared using photochemically induced atom transfer radical polymerization (photoATRP) in the presence of only 50–200 ppm of copper catalyst without the requirement of air removal from the polymerization mixture. The effect of solvent type and volume, ligand‐to‐copper ratio, catalyst concentration, ligand type, and the possible partial replacement of an expensive ligand with cheap simple amines, were investigated. The livingness of the oxygen‐tolerant photoATRP system was investigated by chain extension polymerization and the possibility to prepare block copolymers by chain extension of PMBL‐Br macroinitiator with methyl methacrylate (MMA) as well as by chain extension of PMMA‐Br macroinitiator with PMBL block was studied. It was shown that a concentration of catalyst as low as 50 ppm is sufficient to provide good control over the molecular characteristics and kinetics. Keep it clean: Functional well‐defined homopolymers and block copolymers were prepared from a renewable monomer using low concentrations of a copper‐based catalyst without the necessity to remove air from the polymerization mixture. By addition of a small amount of simple tertiary amines, the polymerization rate was increased and the induction period was shortened.