Living Radical Polymerization by the RAFT Process—A First Update

Moad, Graeme; Rizzardo, Ezio; Thang, San H.

doi:10.1071/ch06250

Cited by 858 publications

(837 citation statements)

References 244 publications

Supporting

Mentioning

787

Contrasting

Unclassified

Order By: Relevance

“…(inside diameter) Â30 cm) using THF as an eluent at 401C at a flow rate of 1.0 ml min À1 employing refractive index (TOSOH RI-8020/21) and ultraviolet detectors (TOYO SODA UV-8II). The columns were calibrated with six standard polystyrene (PS) samples (1.05Â10 3 -5.48Â10 6 , M w / M n ¼1.01-1.15). Before gel permeation chromatography measurement, PMAA 30 -TeMe and PMAA 30 -b-PS-TeMe were modified by methylating the carboxyl group using trimethylsilyldiazomethane as follows.…”

Section: Characterizationmentioning

confidence: 99%

“…TERP includes thermal dissociation and degenerative chain transfer (DT) as control mechanisms, in which the main control mechanism is DT, and has a sufficiently high chain transfer constant (C ex ), which is important for good control/livingness in DT. In a reversible addition-fragmentation chain transfer polymerization, which is a well-known CLRP based on the same DT mechanism, an intermediate radical was formed, [4][5][6] resulting in fewer choices of macroinitiators for the preparation of block copolymers. Because organotellurium compounds operating as control agents in TERP do not form the intermediate radical and types of monomers such as methacrylate, acrylate, styrene, acrylamides, and even non-conjugated monomers can be polymerized by TERP, TERP has a high potential for the precision synthesis of functional polymers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of stirring rate on particle formation in emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene

Moribe

Kitayama

Suzuki

et al. 2011

Polym J

View full text Add to dashboard Cite

Particle formation during the initial stages of emulsifier-free organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene at 601C was investigated at two stirring rates (220 and 1000 r.p.m.), in which the styrene phase floated as a layer on an aqueous phase at 220 r.p.m. or became dispersed as droplets at 1000 r.p.m. A water-soluble TERP agent, poly(methacrylic acid) (PMAA)-methyltellanyl (PMAA 30 -TeMe) and a water-soluble thermal initiator, 4,4¢-azobis(4-cyanovaleric acid), at alkaline pH were used. The control/livingness was better at 1000 r.p.m. than at 220 r.p.m., and the particle size distribution was also affected by the stirring rate: both nanometer-sized and submicrometer-sized particles were observed at 220 r.p.m., and mainly nanometer-sized particles were observed at 1000 r.p.m. Because the percentage of PMAA 30 -TeMe consumed in the initial stage was much higher at 1000 r.p.m. than at 220 r.p.m., self-assembly nucleation preferentially occurred at 1000 r.p.m., resulting in nanometer-sized particles and good control/livingness. Stirring at 1000 r.p.m. only in the initial stage of the emulsion TERP followed by 220 r.p.m. induced good control/livingness and the formation of mainly nanometer-sized particles. It is concluded that a high stirring rate in the initial stage is important for the emulsion TERP of styrene to obtain good control/ livingness and to control the particle formation mechanism.

show abstract

Section: Characterizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of stirring rate on particle formation in emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene

Moribe

Kitayama

Suzuki

et al. 2011

Polym J

View full text Add to dashboard Cite

show abstract

“…The advent of CLRP 4,7 has brought about a renaissance in radical polymerization, and it is now possible to prepare a range of well-defined and complex polymer architectures by free radical means. The most widely used CLRP techniques are nitroxide-mediated polymerization (NMP), [8][9][10] atom transfer radical polymerization (ATRP), 11,12 and reversible addition fragmentation chain transfer (RAFT) polymerization, [13][14][15] but other techniques exist. 4,16 All CLRP systems developed to date operate on the same basic principle of propagating radicals alternating between active and dormant states.…”

Section: Controlled/living Radical Polymerizationmentioning

confidence: 99%

Controlled/living heterogeneous radical polymerization in supercritical carbon dioxide

Zetterlund

Aldabbagh

Okubo

2009

J. Polym. Sci. A Polym. Chem.

105

View full text Add to dashboard Cite

Supercritical carbon dioxide (scCO 2 ) is an inexpensive and environmentally friendly medium for radical polymerizations. ScCO 2 is suited for heterogeneous controlled/living radical polymerizations (CLRPs), since the monomer, initiator, and control reagents (nitroxide, etc.) are soluble, but the polymer formed is insoluble beyond a critical degree of polymerization (J crit ). The precipitated polymer can continue growing in (only) the particle phase giving living polymer of controlled well-defined microstructure. The addition of a colloidal stabilizer gives a dispersion polymerization with well-defined colloidal particles being formed. In recent years, nitroxide-mediated polymerization (NMP), atom transfer radical polymerization (ATRP), and reversible addition fragmentation chain transfer (RAFT) polymerization have all been conducted as heterogeneous polymerizations in scCO 2 . This Highlight reviews this recent body of work, and describes the unique characteristics of scCO 2 that allows composite particle formation of unique morphology to be achieved.

show abstract

“…Reversible addition-fragmentation chain transfer (RAFT) radical polymerization [32][33][34][35] is a powerful synthetic tool mediated by thiocarbonylthio compounds that is simple to perform, highly functional group tolerant, applicable to a wide range of monomeric substrates and experimental conditions, facilitates the synthesis of (co)polymers with narrow molecular weight distributions, predetermined molecular weights, and advanced architectures. [36][37][38][39][40][41][42][43][44][45][46] As a consequence of the degenerative chain transfer mechanism, (co)polymers prepared by RAFT bear very specific end-groups, the chemical nature of which is dependent on the structure of the chain transfer agent (CTA) and, to a lesser extent, the CTA/initiator pair.…”

Section: Introductionmentioning

confidence: 99%

Sequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions as a route to well‐defined mono and bis end‐functionalized poly(N‐isopropylacrylamide)

Chan

Hoyle

et al. 2009

J. Polym. Sci. A Polym. Chem.

208

191

View full text Add to dashboard Cite

Sequential thiol-ene/thiol-ene and thiol-ene/thiol-yne reactions have been used as a facile and quantitative method for modifying end-groups on an N-isopropylacrylamide (NIPAm) homopolymer. A well-defined precursor of polyNIPAm (PNIPAm) was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization in DMF at 70 C using the 1-cyano-1-methylethyl dithiobenzoate/2,2 0 -azobis(2-methylpropionitrile) chain transfer agent/initiator combination yielding a homopolymer with an absolute molecular weight of 5880 and polydispersity index of 1.18. The dithiobenzoate end-groups were modified in a one-pot process via primary amine cleavage followed by phosphine-mediated nucleophilic thiol-ene click reactions with either allyl methacrylate or propargyl acrylate yielding ene and yne terminal PNIPAm homopolymers quantitatively. The ene and yne groups were then modified, quantitatively as determined by 1 H NMR spectroscopy, via radical thiol-ene and radical thiol-yne reactions with three representative commercially available thiols yielding the mono and bis end functional NIPAm homopolymers. This is the first time such sequential thiol-ene/thiol-ene and thiol-ene/thiol-yne reactions have been used in polymer synthesis/end-group modification. The lower critical solution temperatures (LCST) were then determined for all PNIPAm homopolymers using a combination of optical measurements and dynamic light scattering. It is shown that the LCST varies depending on the chemical nature of the end-groups with measured values lying in the range 26-35 C.

show abstract

Living Radical Polymerization by the RAFT Process—A First Update

Cited by 858 publications

References 244 publications

Effect of stirring rate on particle formation in emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene

Effect of stirring rate on particle formation in emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene

Controlled/living heterogeneous radical polymerization in supercritical carbon dioxide

Sequential thiol‐ene/thiol‐ene and thiol‐ene/thiol‐yne reactions as a route to well‐defined mono and bis end‐functionalized poly(N‐isopropylacrylamide)

Contact Info

Product

Resources

About