Nitroxide mediated polymerization polystyrene

Since polystyrene is one of the oldest commercial polymers with over 9 million tonnes/yr of sales, there have been thousands of patents issued covering all aspects of its manufacture and property enhancement. The styrene monomer readily polymerizes to polystyrene either thermally or with free-radical initiators (see Chapter 6 on free-radical polymerization and Chapter 8 on nitroxide-mediated polymerization). Commercial processes for the manufacture of polystyrene are described in Chapter 3 while process modelling and optimization of styrene polymerization is examined in Chapter 5. Styrene also can be polymerized via anionic and Ziegler-Natta chemistries using organometallic initiators. Using free radical and anionic polymerization chemistries, the... 

BaUly B, Donnenwitth AC, Bartholome C, et td. (2006) Silica-polystyrene nanocomposite particles synthesized by nitroxide-mediated polymerization and their encapsulation through miniemulsion polymerization. J Nanomater 2006 1—10... 

Bartholome, C., Beyou, E., Bourgeat-Lami, E., Cassagnau, Ph., ChaumonL Ph., David, L., and Zydowicz, N., Viscoelastic properties and morphological characterization of sUica/polystyrene nanocomposites synthesized hy nitroxide-mediated polymerization. Polymer, 46,9965-9973 (2005). 

E. Kaul, V. Senkovskyy, R. Tkachov, V. Bocharova, H. Komber, M. Stamm, A. Kiriy, Synthesis of a Bifunctional Initiator for Controlled Kumada Catalyst- Transfer Polycondensation/Nitroxide-Mediated Polymerization and Preparation of Poly(3-Hexylthiophene)-Polystyrene Block Copolymer Therefrom. Macromolecules 2010,43,77-81. 

Solomon et al. [75] first used nitroxyl radicals and alkoxyamines in a radical polymerization, but their work was limited to production of low-molecular weight polymers. In 1993, Georges et al. [76] used a mixture of benzoyl peroxide (BPO) initiator and 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) to produce low-polydispersity and high molecular weight polystyrene. Since then many papers about SFRP (also known as nitroxide mediated polymerization or NMP), mainly focused on styrene polymerization in the presence of TEMPO, have been published. Other nitroxide mediators are being developed that are better suited to polymerization of more polar monomers such as meth(acrylates) [77]. 

RAFT polymerization or nitroxide-mediated polymerization (NMP) was used instead of ATRP for the synthesis of the block copolymer of polythiophene and polyisoprene or polystyrene, because ATRP generates materials containing traces of metals from the catalyst [146]. A block copolymer of P3HT and poly (perylene bisimide acrylate) was also synthesized by NMP from a polythiophene macroinitiator (Scheme 51) [147, 148]. This block copolymer is a crystalline-crystalline donor-acceptor block copolymer and shows microphase separation, implying efficient photovoltaic applications. A similar polythiophene macroinitiator for NMP was used for the synthesis of fullerene-grafted rod-coil block copolymers [149]. 

Zhou NC, Xu WJ, Zhang Y, Zhu J, Zhu XL. Preparation and characterization of optically active polystyrene via a chiral nitroxide-mediated polymerization. J Polym Set Part A Polym Chem. 2006 44 1522—1528. 

The first RDRP technique to receive widespread attention, nitroxide-mediated polymerization (NMP), " was developed in our laboratories in the mid 1980 s, though the method did not gain popularity until 1993, when Georges et al. demonstrated the application of NMP to synthesize narrow dispersity polystyrene. The process involves activation by unimolecular dissociation and deactivation by coupling as shown in Scheme 6.1. A variety of stable radical mediated polymerizations (SRMP) have now been reported. ... 

There are a number of other reactions that can be used cycloaddition of an azide group allowed binding of polystyrene [43], while a radical coupling was exploited to graft polymers prepared by a nitroxide-mediated radical polymerization [121]. Other end groups could be used it was shown above how amide bonds were utilized to attach water-soluble polymers amino or hydroxyl moieties are other conventional groups. 

Dynamic formation of graft polymers was synthesized by means of the radical crossover reaction of alkoxyamines by using the complementarity between nitroxide radical and styryl radical (Fig. 8.13) [40]. Copolymer 48 having alkoxyamine units on its side chain was synthesized via atom transfer radical polymerization (ATRP) of TEMPO-based alkoxyamine monomer 47 and MMA at 50°C (Scheme 8.9). The TEMPO-based alkoxyamine-terminated polystyrene 49 was prepared through the conventional nitroxide-mediated free radical polymerization (NMP) procedure [5,41], The mixture of copolymers 48 and 49 was heated in anisole... 

Lohmeijer BGG, Schubert US (2004) Expanding the supramolecular polymer LEGO system nitroxide mediated living free radical polymerization for metallo-supramolecular block copolymers with a polystyrene block. J Polym Sci Part A Polym Chem 42 4016-4027... 

Nitroxide mediated radical polymerization (NMRP) was pioneered by Riz-zardo and Solomon in the mid-1980s [1]. Their work went unnoticed for almost a decade until Georges et al. reported the preparation of narrow polydispersity (PD) (<1.2) polystyrene using NMRP [2]. This report initiated an explosion of research aimed at both understanding the mechanism of NMRP and also utilizing it to prepare block copolymers. This chapter describes the application and limitations of NMRP for making styrene-containing block copolymers. 

HU1 Hua, F., Jiang, X., and Zhao, B., Well-defined thermosensitive, water-soluble polyaciylates and polystyrenics with short pendant oligo(ethylene glycol) groups synthesized by nitroxide-mediated radical polymerization, J. Polym. Sci. Part A Polym. Chem., 44, 2454, 2006. 

Fig. 14 Colloidal characteristics of the polyAA-stabilized particles prepared by surfactant-free nitroxide-mediated emulsion polymerization of styrene (a) pH-dependence of the diameters ( ), (b) stability of the polystyrene particles with pH, and (c) influence of the initial polyAA-SGl concentration and of the target degree of polymerization, )Pn,th, on the particle diameter...

Matsuno R, Otsuka H, Takahara A (2006) Polystyrene-grafted titanium oxide nanoparticles prepared through surface-initiated nitroxide-mediated radical polymerization and their application to polymer hybrid thin films. Soft Matter 2(5) 415... 

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