TEMPO-Mediated n-Butyl Acrylate Polymerizations

Abstract

Polymerizations of n-butyl acrylate under stable free radical polymerization (SFRP) conditions, using TEMPO as the nitroxide mediator, are reported at reaction temperatures between 133 and 135 °C. The polymerizations proceed in a living manner under both bulk and miniemulsion conditions with polydispersities of around 1.3. Plots of number-average molecular weight vs conversion and ln([M]0/[M]) vs time are linear, indicating a controlled polymerization. It is argued that the ability of a particular nitroxide to control the polymerization of n-butyl acrylate is not only due to a favorable equilibrium constant (K) between the dormant and active polymeric species in the system but also due to the amount of excess nitroxide that is present. In these experiments excess TEMPO is controlled by the continuous addition of a dilute solution of ascorbic acid or an ascorbic acid derivative, leading to successful n-butyl acrylate polymerizations. Chain extension of a homopoly(n-butyl acrylate) prepared under miniemulsion conditions is demonstrated.

Recent advances in controlled/living radical polymerization in emulsion and dispersion

“…A number of persistent radicals have been examined as mediators in the SFRP process. They include 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), [103][104][105] other nitroxides including N-t-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl)nitroxide (called SG1) [106][107][108] and 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and its derivatives 109,110 as well as triazolinyl 111,112 and verdazyl 113,114 stable radicals, employed with free radical initiators to initiate polymerization (Fig. 3).…”

Chain extension and block copolymer synthesis using silane radical atom abstraction coupled with nitroxide mediated polymerization

“…Two monomers were chosen in this study: one predicted to behave similarly to St in chain 10 elongation phase ( p-methylstyrene, MSt), and one expected to behave in a substantially different manner (n-butyl acrylate, BA). n-Butyl acrylate (BA) has previously been used in NMP reactions mediated by TEMPO or TEMPO derivatives by others [18,28,29]. Reactions were run in an analogous manner to the chain extension trials discussed above, with PStBr again used as the precursor.…”

Synthesis of Poly(lauryl acrylate) by Single‐Electron Transfer/Degenerative Chain Transfer Living Radical Polymerization Catalyzed by Na2S2O4 in Water

“…Several techniques have been proposed to allow the control over molecular weight, molecular weight distribution, macromolecular architectures, and end-functional groups using at the same time a radical process. The most common strategies include reversible addition fragmentation chain transfer (RAFT), [7] nitroxide-mediated living radical polymerization (NMP), [8] and metal-catalyzed living radical polymerization. [9,10] With regard to LA, this is the only reference available in literature.…”