Buback, Michael M.

[["dc.bibliographiccitation.firstpage","1484"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Australian Journal of Chemistry"],["dc.bibliographiccitation.lastpage","1487"],["dc.bibliographiccitation.volume","62"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Meiser, Wibke"],["dc.contributor.author","Vana, Philipp"],["dc.date.accessioned","2018-11-07T08:33:50Z"],["dc.date.available","2018-11-07T08:33:50Z"],["dc.date.issued","2009"],["dc.description.abstract","Reversible addition-fragmentation chain transfer (RAFT) polymerizations of methyl methacrylate (MMA) in bulk at 60 degrees C were performed at five pressures up to 200 MPa using 2-(2'-cyanopropyl)dithiobenzoate (CPDB) as RAFT agent at concentrations between 1.5 x 10(-3) and 2.0 x 10(-2) mol L(-1). Applying high pressure during polymerization increases the rate of polymerization, but no effect on polydispersity was observed. Molecular weight distributions and average molecular weights of the final polymer indicated the successful control of MMA polymerization even at low CPDB concentrations. The slight retardation observed is adequately described by the dependence the termination rate coefficient, k(t), on the chain-length."],["dc.identifier.doi","10.1071/CH09219"],["dc.identifier.isi","000271976400007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17683"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Csiro Publishing"],["dc.relation.issn","0004-9425"],["dc.title","Mechanism of CPDB-Mediated RAFT Polymerization of Methyl Methacrylate: Influence of Pressure and RAFT Agent Concentration"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","8088"],["dc.bibliographiccitation.issue","21"],["dc.bibliographiccitation.journal","Macromolecules"],["dc.bibliographiccitation.lastpage","8097"],["dc.bibliographiccitation.volume","49"],["dc.contributor.author","Smolne, Sebastian"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Demeshko, Serhiy"],["dc.contributor.author","Matyjaszewsk, Krzysztof"],["dc.contributor.author","Meyer, Franc"],["dc.contributor.author","Schroeder, Hendrik"],["dc.contributor.author","Simakova, Antonina"],["dc.date.accessioned","2018-11-07T10:05:51Z"],["dc.date.available","2018-11-07T10:05:51Z"],["dc.date.issued","2016"],["dc.description.abstract","A speciation analysis for Fe-mesohemin-(MPEG(500))(2)-mediated reversible-deactivation radical polymerization (RDRP) in aqueous solution was carried out by a combination of visible (vis) and Fe-57 Mossbauer spectroscopy. The results were used within kinetic studies of ATRP and OMRP reactions via highly time-resolved EPR spectroscopy. ATRP control was effective with the rate coefficient for deactivation clearly exceeding the one for formation of organometallic species. Deactivation rate coefficients increase by more than 1 order of magnitude in passing from polymerization in 30 to 90 wt % H2O. Media with water contents of and above 70 wt % are well suited for controlled ATRP. The Fe-mesohemin catalyst provides an exceptionally high ATRP equilibrium constant even at ambient temperature, which approaches the one of highly active Cu catalysts."],["dc.identifier.doi","10.1021/acs.macromol.6b01774"],["dc.identifier.isi","000387519200006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38983"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","1520-5835"],["dc.relation.issn","0024-9297"],["dc.title","Kinetics of Fe-Mesohemin-(MPEG(500))(2)-Mediated RDRP in Aqueous Solution"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","5590"],["dc.bibliographiccitation.issue","19"],["dc.bibliographiccitation.journal","Polymer"],["dc.bibliographiccitation.lastpage","5598"],["dc.bibliographiccitation.volume","48"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Frauendorf, Holm"],["dc.contributor.author","GUnzler, Fabian"],["dc.contributor.author","Vana, Philipp"],["dc.date.accessioned","2018-11-07T10:58:38Z"],["dc.date.available","2018-11-07T10:58:38Z"],["dc.date.issued","2007"],["dc.description.abstract","The type and number of end groups of poly(methyl methacrylates) from free-radical polymerization with six diacyl peroxides, R-(CO)O- O(CO)-R. acting as initiators have been analyzed via electrospray ionization mass spectrometry using an ion trap and additionally Fourier transform ion cyclotron resonance for mass detection. The polymerizations were carried out in benzene solution at high initiator concentration to yield low molecular weight polymer. With R being an alkyl group, only R moieties are observed as end groups. For each oligomer size, molecules with one or two such end groups are formed, depending on whether termination occurs via disproportionation or combination. With R being an aryl type, as in di-benzoyl and di-naphthoyl peroxides, both R and R-(CO)O moieties are detected as polymeric end groups. Because of aromatic delocalization. fractions of the arylic R-(CO)O-center dot radicals are sufficiently long living at 95 degrees C to add to a monomer molecule prior to undergo decarboxylation. (C) 2007 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.polymer.2007.07.041"],["dc.identifier.isi","000250161000018"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50507"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Sci Ltd"],["dc.relation.issn","0032-3861"],["dc.title","Electrospray ionization mass spectrometric end-group analysis of PMMA produced by radical polymerization using diacyl peroxide initiators"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1386"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Macromolecules"],["dc.bibliographiccitation.lastpage","1393"],["dc.bibliographiccitation.volume","50"],["dc.contributor.author","Kattner, Hendrik"],["dc.contributor.author","Drawe, Patrick"],["dc.contributor.author","Buback, Michael"],["dc.date.accessioned","2018-11-07T10:27:10Z"],["dc.date.available","2018-11-07T10:27:10Z"],["dc.date.issued","2017"],["dc.description.abstract","Via the single pulse-pulsed laser polymerization-electron paramagnetic resonance (SP-PLP-EPR) technique, the chain-length-dependent termination of 5 and 10 wt % sodium methacrylate (NaMAA) in aqueous solution was measured from 5 to 60 degrees C. The rate coefficients k(t)(i,i) for termination of two ionized radicals of identical size i were analyzed by the composite model. Three out of the four composite-model parameters behave similarly to nonionized monomers, whereas the fourth parameter, the rate coefficient for termination of two radicals of chain length unity, k(t)(1,1), exhibits a distinctly different behavior. The temperature dependence of k(t)(1,1) is significantly below the one of fluidity (inverse solution viscosity). Moreover, absolute k(t)(1,1) increases with NaMAA concentration, i.e., toward higher viscosity. Both observations indicate that the termination kinetics of ionized radicals largely differs from the Smoluchowski-type behavior."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft"],["dc.identifier.doi","10.1021/acs.macromol.6b02641"],["dc.identifier.isi","000395358500011"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43195"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","1520-5835"],["dc.relation.issn","0024-9297"],["dc.title","Chain-Length-Dependent Termination of Sodium Methacrylate Polymerization in Aqueous Solution Studied by SP-PLP-EPR"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","779"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Australian Journal of Chemistry"],["dc.bibliographiccitation.lastpage","787"],["dc.bibliographiccitation.volume","60"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Junkers, Thomas"],["dc.contributor.author","Theis, Thomas"],["dc.contributor.author","Vana, Philipp"],["dc.date.accessioned","2018-11-07T11:06:03Z"],["dc.date.available","2018-11-07T11:06:03Z"],["dc.date.issued","2007"],["dc.description.abstract","The chain-length dependence of the termination rate coefficient, k(t), in methyl acrylate ( MA) and dodecyl acrylate (DA) radical polymerization has been determined via the single pulse pulsed-laser polymerization near-infrared reversible addition-fragmentation chain transfer (SP-PLP-NIR-RAFT) technique. Polymerization is induced by a laser SP and the resulting decay in monomer concentration, c(M), is monitored via NIR spectroscopy with a time resolution of microseconds. A RAFT agent ensures the correlation of radical chain length and monomer-to-polymer conversion. The obtained rate coefficients for termination of two radicals of approximately the same chain length, i, are represented by power-law expressions, k(t)(i, i)alpha i(-alpha). For both monomers, composite model behaviour of k(t)(i, i) showing two distinct chain length regimes is observed. The exponent as referring to short chain lengths is close to unity, whereas the exponent alpha(1), which characterizes the chain-length dependency of large radicals, is slightly above the theoretical value for coiled chain-end radicals. The crossover chain length, i(c), which separates the two regions, decreases from MA(i(c) = 30) to DA(i(c) = 20). The results for MA and DA are consistent with earlier data reported for butyl acrylate. There appears to be a correlation of as and ic with chain flexibility."],["dc.identifier.doi","10.1071/CH07236"],["dc.identifier.isi","000250003800010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52214"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Csiro Publishing"],["dc.publisher.place","Clayton"],["dc.relation.conference","29th Australasian Polymer Symposium"],["dc.relation.eventlocation","Hobart, AUSTRALIA"],["dc.relation.issn","1445-0038"],["dc.relation.issn","0004-9425"],["dc.title","Chain-length-dependent termination in acrylate radical polymerization studied via pulsed-laser-initiated RAFT polymerization"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1299"],["dc.bibliographiccitation.issue","16"],["dc.bibliographiccitation.journal","Macromolecular Rapid Communications"],["dc.bibliographiccitation.lastpage","1305"],["dc.bibliographiccitation.volume","27"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Vana, Philipp"],["dc.date.accessioned","2018-11-07T09:25:01Z"],["dc.date.available","2018-11-07T09:25:01Z"],["dc.date.issued","2006"],["dc.description.abstract","The debate on the mechanism of dithiobenzoate-mediated RAFT polymerization may be resolved by including the reaction between a propagating radical and the star-shaped combination product from irreversible termination into the kinetic scheme. By this step, a highly reactive propagating radical and a not overly stable three-arm star species are transformed into the resonance-stabilized RAFT intermediate radical and a very stable polymer molecule. The time evolution of concentration is discussed for the main-equilibrium range of CDB-mediated methyl acrylate polymerization."],["dc.identifier.doi","10.1002/marc.200600317"],["dc.identifier.isi","000240426600001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29969"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1022-1336"],["dc.title","Mechanism of dithiobenzoate-mediated RAFT polymerization: A missing reaction step"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","604"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Macromolecular Rapid Communications"],["dc.bibliographiccitation.lastpage","609"],["dc.bibliographiccitation.volume","34"],["dc.contributor.author","Wang, Y. U."],["dc.contributor.author","Schroeder, Hendrik"],["dc.contributor.author","Morick, Joachim"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Matyjaszewski, Krzysztof"],["dc.date.accessioned","2018-11-07T09:26:02Z"],["dc.date.available","2018-11-07T09:26:02Z"],["dc.date.issued","2013"],["dc.description.abstract","High-pressure atom transfer radical polymerization (ATRP) of n-butyl acrylate (BA) is performed in acetonitrile (MeCN) with CuIBr/TPMA [TPMA: tris(2-pyridylmethyl)-amine] as the catalyst up to 5 kbar. Increasing either pressure or temperature significantly enhances the rate of polymerization, while retaining control over the polymerization. The polymerizations under high pressure could be efficiently performed with very low levels of Cu catalyst in the absence of any reducing agents. For example, 100 ppm Cu is sufficient to catalyze the polymerization of BA with targeted degree of polymerization (DPT) = 1000. The conversion reached 79% in 3.0 h at 80 degrees C providing PBA with Mn = 112 000, Mw/Mn = 1.12. Since the initial CuI-to-initiator molar ratio is 0.05:1, the molar percentage of terminated chains should remain <5%. For DPT = 10 000 using only 50 ppm Cu catalyst, a polymer with molecular weight Mn = 612 000 (DP = 4800) was obtained at 67% conversion."],["dc.identifier.doi","10.1002/marc.201200752"],["dc.identifier.isi","000317082600008"],["dc.identifier.pmid","23417957"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/30203"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1521-3927"],["dc.relation.issn","1022-1336"],["dc.title","High-Pressure Atom Transfer Radical Polymerization of n-Butyl Acrylate"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","128970"],["dc.bibliographiccitation.journal","Chemical Engineering Journal"],["dc.bibliographiccitation.volume","415"],["dc.contributor.author","Zapata-Gonzalez, Ivan"],["dc.contributor.author","Hutchinson, Robin A."],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Rivera-Magallanes, Axel"],["dc.date.accessioned","2021-06-01T09:41:13Z"],["dc.date.available","2021-06-01T09:41:13Z"],["dc.date.issued","2021"],["dc.identifier.doi","10.1016/j.cej.2021.128970"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/84850"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["dc.relation.issn","1385-8947"],["dc.title","Kinetic importance of the missing step in dithiobenzoate-mediated RAFT polymerizations of acrylates"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3111"],["dc.bibliographiccitation.issue","14"],["dc.bibliographiccitation.journal","Polymer"],["dc.bibliographiccitation.lastpage","3118"],["dc.bibliographiccitation.volume","50"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Junkers, Thomas"],["dc.contributor.author","Mueller, Matthias"],["dc.date.accessioned","2018-11-07T08:27:48Z"],["dc.date.available","2018-11-07T08:27:48Z"],["dc.date.issued","2009"],["dc.description.abstract","The propagation and termination rate coefficients for bulk polymerization of the butyl acrylate dimer (BA dimer) are determined by pulsed laser techniques. The rate coefficient for propagation, k(p), is deduced for temperatures from 20 to 90 C via the pulsed laser polymerization-size exclusion chromatography (PLP-SEC) method at pulse repetition rates between 1 and 10 Hz. The Arrhenius parameters were found to be: E(A)(k(p))=(34.2 +/- 1.0) kJ mol(-1) and A(k(p))/L mol(-1) s(-1) = (1.08 +/- 0.49) x 10(7) L mol(-1) s(-1). The termination rate coefficient, k(t), has been measured via SP-PLP-ESR, single pulse-pulsed laser polymerization in conjunction with time-resolved electron spin resonance detection of radical concentration. The resulting Arrhenius parameters as deduced from the temperature range -15 to +30 degrees C are: E(A)(< k(t)>)=(22.8 +/- 3.7) kJ mol(-1) and log(A/L mol(-1) s(-1)) = 10.6 +/- 1. The chain-length dependence of k(t) was studied at 30 degrees C. For short chains a significant dependence was found which may be represented by an exponent alpha=0.79 in the power-law expression k(t)(i)=k(t)(0)i(-alpha). (C) 2009 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.polymer.2009.04.036"],["dc.identifier.isi","000267859700008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16280"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Sci Ltd"],["dc.relation.issn","0032-3861"],["dc.title","Free-radical propagation and termination kinetics of the butyl acrylate dimer studied by pulsed laser polymerization techniques"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1400"],["dc.bibliographiccitation.issue","13"],["dc.bibliographiccitation.journal","Macromolecular Chemistry and Physics"],["dc.bibliographiccitation.lastpage","1409"],["dc.bibliographiccitation.volume","212"],["dc.contributor.author","Schrooten, Jens"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Hutchinson, Robin A."],["dc.contributor.author","Lacik, Igor"],["dc.date.accessioned","2018-11-07T08:54:42Z"],["dc.date.available","2018-11-07T08:54:42Z"],["dc.date.issued","2011"],["dc.description.abstract","Termination kinetics of 1-vinylpyrrolidin-2-one radical polymerization in aqueous solution has been studied at 40 degrees C between 20 and 100 wt.-% VP. The /k(p) values from laser single-pulse experiments with microsecond time-resolved NIR detection of monomer conversion, in conjunction with k(p) from literature, yield chain-length-averaged termination rate coefficients, . Because of better signal-to-noise quality, experiments were carried out at 2 000 bar, but also at 1 500, 1 000, and 500 bar, thus allowing for estimates of at ambient pressure. The dependence of on monomer conversion indicates initial control by segmental diffusion followed by translational diffusion and finally reaction diffusion control. To assist the kinetic studies, viscosities of VP-water mixtures at ambient pressure have been determined."],["dc.description.sponsorship","BASF SE"],["dc.identifier.doi","10.1002/macp.201100021"],["dc.identifier.isi","000292541600008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22734"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1022-1352"],["dc.title","Termination Kinetics of 1-Vinylpyrrolidin-2-one Radical Polymerization in Aqueous Solution"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]