Photoinduced Iron(III)-Mediated Atom Transfer Radical Polymerization with In Situ Generated Initiator: Mechanism and Kinetics Studies

Abstract

In this work, a photoinduced iron(III)-based atom transfer radical polymerization (ATRP) without any reducing agents and additional initiators was suggested. In addition, detailed kinetic studies, including the effects of ligand and catalyst concentrations on polymerization kinetics, and the polymerization behaviors using various solvents and monomer types were evaluated for this new polymerization technique. Results showed that photoinduced iron(III)-mediated ATRP using 5000 ppm catalyst loading with 1 equiv of ligand in N,N-dimethylformamide (DMF) produced poly(methyl methacrylate) with low molecular weight distribution (M w /M n < 1.45) and that the evolution of molecular weight (M n ) was linearly related to monomer conversion. 1 H NMR analysis confirmed that the resulting polymer prepared through photoinduced ATRP in the present work was initiated by methyl 2,3-dichloroisobutyrate. Facile temporal control and the successful chain extension highlighted the good chain-end functionality of the resulting polymers. In short, this work provided a study on additional alkyl halides initiator-free ATRP and its application in the synthesis of methacrylate polymers with narrow M w /M n .

Photoinduced Organocatalyzed Atom Transfer Radical Polymerization Using Continuous Flow

“…1–5 In the past two decades atom transfer radical polymerization (ATRP) has emerged as the most widely applied CRP. 6,7 The popularity of ATRP is largely due to use of readily available reagents, robust implementation, and functional group tolerance.…”

Electrochemical Atom Transfer Radical Polymerization in Miniemulsion with a Dual Catalytic System

“…43–49 Currently, however, several catalyst (re)-generation methods allow performing ATRP reactions with low ppm levels of catalysts; these techniques include activators regenerated by electron transfer (ARGET) ATRP, 50–58 initiators for continuous activator regeneration (ICAR) ATRP, 50,59–65 supplemental activator and reducing agent (SARA) ATRP, 66–73 photoinduced ATRP (photoATRP), 74–85 85 and electrochemically mediated ATRP ( e ATRP, the method used in this work). 86–97 …”

Reversible Deactivation Radical Polymerization: State-of-the-Art in 2017

“…Parallel to the reduction cycle for copper mediated photo-ATRP described above, polymerization only took place in the presence of irradiation and was completely suppressed in the absence of light. Similar oxidative cycles were also implemented for photo-ATRP of acrylates and methacrylates using transition metal photocatalysts such as fac-Ir(ppy) 3 (91-95) and iron halides (96)(97)(98)(99)(100)(101)(102)(103). For instance, iron mediated photo-ATRP for polymerization of methacrylates was demonstrated without the need for additional ligands, reducing agents, and radical initiators (96).…”