Nitroxide mediated and atom transfer radical graft polymerization of atactic polymers onto syndiotactic polystyrene

Abstract

-'Living' radical graft polymerization was employed to prepare graft copolymers with nitroxidemediated arylated syndiotactic polystyrene as the backbone and polystyrene (PS), poly(p-methylstyrene) (PMS) and poly(methylmethacrylate) (PMMA) as branches. A two-stage process has been developed to synthesize the macroinitiator. First, syndiotactic polystyrene (sPS) was modified by the Friedel-Crafts reaction to introduce chlorine; second, the chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH). The resulting macroinitiator (sPS-TEMPO) for 'living' free radical polymerization was then heated in the presence of styrene and pmethylstyrene to form graft and block copolymers. We used the obtained copolymer and N-bromosuccinimide as brominating agent to achieve polymers with bromine groups. This brominated copolymer was used as a macroinitiator for polymerizing methyl methacrylate in the presence of the CuBr/bpy catalyst system. The formation of the graft and block copolymers was confirmed by DSC, 1 H NMR and FTIR spectroscopy. This approach using macroinitiators is an effective method for the preparation of new materials.

Polymericaly modified clays to preparation of polystyrene nanocomposite by nitroxide mediated radical polymerization and solution blending methods

“…TEMPO iniferter were prepared by the method reported by our research group previously . Styrene monomer (St) was obtained from Tabriz Polynar Company (Tabriz, Iran) and p ‐Chloromethyl styrene (CMSt) as a comonomer, from Fluka Chemical (Seelze, Germany) were distilled under a reduced pressure before use.…”

Synthesis of Cellulose-graft-Polychloromethylstyrene-graft-Polyacrylonitrile Terpolymer/Organoclay Bionanocomposite by Metal Catalyzed Living Radical Polymerization and Solvent Blending Method

“…Therefore, there is a lack of control over molecular weight and polydispersity of the graft chains [18]. These problems can be circumvented through applying of living radical polymerization methods such as: atom transfer radical polymerizations (ATRP) [19][20][21], nitroxide-mediated polymerizations (NMP) [22][23][24] and reversible addition-fragmentation chain transfer polymerization (RAFT) [25][26][27]. Metalcatalyzed living-radical polymerization, generally called atom-transfer radical polymerization (ATRP), is one of the most widely used methods for controllable radical polymerization and is based on the reversible reaction of low oxidation-state metal complexes with an alkyl halide, generating radicals and the corresponding high-oxidation state metal complexes with a coordinated halide ligand (Scheme 1) [28].…”

Synthesis of conductive PSt-g-PANi/TiO2 nanocomposites by metal catalyzed and chemical oxidative polymerization

“…These composites are attractive because they can combine with the properties of other compounds, and the composites of PANI with graphite, [7,8] carbon nanotubes [9] and carbon black (CB) have been accepted to effectively improve the electric conductivity. As well as, encapsulation of metal nanoparticles into CPs results in hybrid organicinorganic nanocomposites that exhibit enhanced thermal stability, electrochemical, catalytic, magnetic, mechanical, Downloaded by [RMIT University Library] at 08: 48 25 June 2016 polymerization, using stable nitroxide radicals such as TEMPO, [36][37][38][39][40][41][42][43][44] and atom transfer radical polymerization (ATRP). [45][46][47][48][49][50][51][52][53] Because ATRP allows better control over the molecular weight and distribution of the target polymer, much attention has been paid to the use of this polymerization method in the synthesis of polymer brushes from a surface.…”