Analysis of pulsed-laser-generated molecular weight distributions for the determination of propagation rate coefficients

Hutchinson, Robin A.; Aronson, M. T.; Richards, J. R.

doi:10.1021/ma00076a017

Cited by 165 publications

(161 citation statements)

References 3 publications

(5 reference statements)

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“…In a series of papers [1][2][3][4], it has been established that the so-called PLP-SEC technique, first introduced by Olaj and coworkers [5,6], provides reliable rate coefficients for the propagation reaction if the data fulfill certain consistency criteria [2,7]. A typical experiment involves the irradiation of a mixture consisting of monomer and photoinitiator by an evenly spaced sequence of laser pulses.…”

Section: Introductionmentioning

confidence: 99%

Critically evaluated propagation rate coefficients in free-radical polymerizations: Part III. Methacrylates with cyclic ester groups (IUPAC Technical Report)

Beuermann

2003

Pure and Applied Chemistry

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Republication or reproduction of this report or its storage and/or dissemination by electronic means isAbstract: Propagation rate coefficients, k p , as a function of temperature, are reported for bulk free-radical homopolymerizations of oxiranylmethyl, cyclohexyl, and benzyl methacrylate at ambient pressure and low conversion. The data were obtained from experiments combining pulsed-laser initiated polymerization and size-exclusion chromatography. The data determined from experiments carried out in independent laboratories obey the consistency criteria established for this technique. The rate coefficients for the three monomers are well represented by a single Arrhenius relation.

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Section: Introductionmentioning

confidence: 99%

Critically evaluated propagation rate coefficients in free-radical polymerizations: Part III. Methacrylates with cyclic ester groups (IUPAC Technical Report)

Beuermann

2003

Pure and Applied Chemistry

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“…The time window for radical detection is generally limited by the decay of spin polarization, not by the decay of radical concentration. On the other hand, steadystate ESR has the opportunity to study free radicals without the need for spin polarization, but on a time scale determined by the radical lifetimes (several hundred µs to ms 34 ). The combination of TR-CW ESR and SS-CW ESR, which provides a means of tracking radicals over the time scale from hundreds of nanoseconds to milliseconds, was therefore employed in this investigation.…”

Section: Introductionmentioning

confidence: 99%

Electron Spin Resonance and Laser Flash Photolysis Study of Radical Addition to Vinyl Acrylate and Related Alkenes

2001

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Addition of two radicals (diphenyl phosphinoyl and 2-hydroxy-2-propyl) to the bifunctional alkene, vinyl acrylate, was studied by both time-resolved (TR) and steady-state (SS) ESR and laser flash photolysis (LFP). The adduct radicals are predominately a result of tail addition (addition to the unsubstituted carbon atom) of the acrylate double bond. Chemical structures of the adducts were established by comparison of the observed ESR spectra with those of adducts of the same reactive radicals to structurally related alkenes, tert-butyl acrylate and vinyl pivalate, which have only one type of double bond. Adducts of bulky phosphinoyl radicals to the acrylates demonstrate hindered rotation and a cis-trans isomerization at room temperature. The structure of the adduct radicals and the reactivity of the two radicals are discussed. Absolute rate constants for the addition of the phosphinoyl radical to the alkenes were measured by LFP in ethyl acetate at 296 K. A rate constant of k add ) (33 ( 1) × 10 6 M -1 s -1 was found for vinyl acrylate. The latter value is ∼1.5 times higher than that for tert-butyl acrylate (k add ) (22 ( 1) × 10 6 M -1 s -1 ) and ∼17 times higher than that for vinyl pivalate (k add ) (2.0 ( 0.1) × 10 6 M -1 s -1 ). These rate constants are consistent with conclusions derived from the ESR data. The results provide some insights into free radical polymerization of vinyl acrylate and vinyl ethers.

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“…This results in poor control due to slow deactivation. In the kinetic aspect, the velocity of a typical ATRP reaction increased with the monomer and radical concentration, as predicted by equations (1)- (4) [39]. Furthermore, in equation (4) (5)) [39], the k p of MMA can be calculated, and the concentration of propagating radicals [M · ] can be obtained (Table 2):…”

Section: Resultsmentioning

confidence: 94%

AGET ATRP of Methyl Methacrylate by Silica-Gel-Supported Copper(II) Chloride/2-(8-Heptadecenyl)-4,5-Dihydro-1H-Imidazole-1-Ethylamine

et al. 2010

Designed Monomers and Polymers

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Copper-mediated activators generated by electron transfer for atom transfer radical polymerization (AGET ATRP) of methyl methacrylate (MMA) were studied in the presence of 2-(8-heptadecenyl)-4,5-dihydro-1H-imidazole-1-ethylamine (OLC) as ligands that served not only as ligands but also as reducing agents. Wellcontrolled poly(methyl methacrylate) (PMMA) with narrow molecular weight distribution (M w /M n = 1.29) was prepared in the presence of Cu(II)Cl 2 /OLC ligand via AGET ATRP. Chain extension of PMMA with MMA was successful and demonstrated well-maintained end-group functionality. Well-controlled PMMA with narrow molecular weight distribution was also prepared via AGET ATRP in the presence of Cu(II) and OLC without any additional reducing agent. A chemically modified silica gel with OLC immobilized on its surface coordinated with CuCl 2 was successfully used as a catalyst system for AGET ATRP of methyl methacrylate using ethyl 2-bromopropanoate as initiator. Also well-controlled poly(methyl methacrylate) (PMMA) with narrow molecular weight distribution (M w /M n = 1.46) was prepared in the presence of SiO 2 -OLC-Cu(II)Cl 2 complexes catalyst via AGET ATRP.

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Analysis of pulsed-laser-generated molecular weight distributions for the determination of propagation rate coefficients

Cited by 165 publications

References 3 publications

Critically evaluated propagation rate coefficients in free-radical polymerizations: Part III. Methacrylates with cyclic ester groups (IUPAC Technical Report)

Critically evaluated propagation rate coefficients in free-radical polymerizations: Part III. Methacrylates with cyclic ester groups (IUPAC Technical Report)

Electron Spin Resonance and Laser Flash Photolysis Study of Radical Addition to Vinyl Acrylate and Related Alkenes

AGET ATRP of Methyl Methacrylate by Silica-Gel-Supported Copper(II) Chloride/2-(8-Heptadecenyl)-4,5-Dihydro-1H-Imidazole-1-Ethylamine

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