New and improved routes to alkoxyamine initiators for controlled radical polymerisation

Abstract

Abstract-O-substituted hydroxylamines were synthesized in almost quantitative yields using ultrasound and Mn(OAc) 3 (in substance or regenerated in situ by an oxidizing agent) as electron-transfer agent. Two novel synthetic methods for the synthesis of alkoxyamines from organic halides and stable nitroxide radicals are introduced. One of them utilises cyancobalamine (vitamine B 12 ), the other SmI 2 as catalyst and magnesium metal as reductive agent. The yields are good for the first method and excellent for the second. The initiators were tested in controlled radical polymerisation of styrene, methylmethacrylate and 4-vinylpyridine.

NMRP and ATRP Double Initiators for the Formation of Binary Polymer Brushes via Grafting-From Methods

“…Following our previous studies on the synthesis of NMRP starters [18,19] we prepared compound 7 according to Scheme 2, which bears a SiCl 3 group for grafting on Si wafers via reaction of the SiCl 3 group with -OH groups on the wafer surface.…”

The enhanced adsorption properties of molecular imprinted polymer material prepared using nitroxide-mediated Radical Deactivation Reversible Polymerization

“…The molecular imprinted polymers (MIPs) and non-imprinted polymers (NIPs) were prepared using nitroxide-mediated controlled radical polymerization (NMRP) and by conventional free radical polymerization (FRP) of methacrylic acid. Imprinted polymer MIP-NMRP and nonimprinted polymer NIP-NMRP were synthesized using N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)]nitroxide (Styryl/DEPN) as initiator, which was prepared as reported in the literature [29,30]. SiO2-MPTS (1 g) was dispersed in 1,4-dioxane (15 mL) in a Schlenk flask.…”

New Alkoxyamines for Controlled Radical Polymerisations

“…However, there are some limitations of nitroxide-mediated procedures: their incompatibility with many vinyl monomer families [18], laborious synthesis of starting alkoxyamines [19] and high temperatures required for polymerisation [3][4][5][6]. The first problem was solved by the development of the phosphonate derivative DEPN (diethylphosphonic acid esther nitroxide, Scheme 1) by Gnanou and Tordo [20] and the work of Hawker and others [7][8][9][10][11][12][13][14][15][16][17] based on the extensive variation of the structure 2.…”

“…We tried to solve the remaining problems in our previous work [19] and also this one. We have explored a range of different nitroxides and their associated alkoxyamines in an effort to develop a new system suitable for the polymerization at lower temperatures.…”