Buback, Michael M.

[["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","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"]]

[["dc.bibliographiccitation.firstpage","1463"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Pure and Applied Chemistry"],["dc.bibliographiccitation.lastpage","1469"],["dc.bibliographiccitation.volume","79"],["dc.contributor.author","Beuermann, Sabine"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Kuchta, Frank-Dieter"],["dc.contributor.author","Lacik, Igor"],["dc.contributor.author","van Herk, Alex M."],["dc.date.accessioned","2018-11-07T11:00:27Z"],["dc.date.available","2018-11-07T11:00:27Z"],["dc.date.issued","2007"],["dc.description.abstract","Critically evaluated propagation rate coefficients, k(P), for free-radical polymerization of methacrylic acid, MAA, in aqueous solution are presented. The underlying k(P) values are from two independent sources, which both used the IUPAC-recommended technique of pulsed-laser-initiated polymerization (PLP) in conjunction with molar mass distribution (MMD) analysis of the resulting polymer by size-exclusion chromatography (SEC). Different methods of measuring the MMD of the poly(MAA) samples have, however, been used: (i) direct analysis via aqueous-phase SEC and (ii) standard SEC with tetrahydrofuran as the eluent carried out on poly(methyl methacrylate) samples obtained by methylation of the poly(MAA) samples from PLP. Benchmark k(P) values for aqueous solutions containing 15 mass % MAA are presented for temperatures between 18 and 89 degrees C. The Arrhenius pre-exponential and activation energy of k(P) at 15 mass % MAA are 1.54 x 10(6) L mol(-1) s(-1) and 15.0 kJ mol(-1), respectively. Also reported are critically evaluated k(P) values for 25 degrees C over the entire MAA concentration range from dilute aqueous solution to bulk polymerization."],["dc.identifier.doi","10.1351/pac200779081463"],["dc.identifier.isi","000248391900010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50919"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Int Union Pure Applied Chemistry"],["dc.relation.issn","0033-4545"],["dc.title","Critically evaluated rate coefficients for free-radical polymerization. Part 6: Propagation rate coefficient of methacrylic acid 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","8197"],["dc.bibliographiccitation.issue","21"],["dc.bibliographiccitation.journal","Industrial & Engineering Chemistry Research"],["dc.bibliographiccitation.lastpage","8204"],["dc.bibliographiccitation.volume","47"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Hutchinson, Robin A."],["dc.contributor.author","Kasak, Peter"],["dc.contributor.author","Lacik, Igor"],["dc.contributor.author","Stach, Marek"],["dc.contributor.author","Utz, Inga"],["dc.date.accessioned","2018-11-07T11:09:14Z"],["dc.date.available","2018-11-07T11:09:14Z"],["dc.date.issued","2008"],["dc.description.abstract","The batch free-radical polymerization of nonionized methacrylic acid (MAA) in aqueous solution has been investigated at 50 degrees C and initial monomer concentrations Lip to 30 wt % MAA. The rate of conversion increases as the initial weight fraction of MAA decreases, a result explained by the dependence of the propagation rate coefficient, k(p), on monomer concentration. The conversion profiles measured at different MAA and initiator levels are represented by a polymerization model with con version-dependent k(p) taken from literature, and the termination rate coefficient, k(1), represented by a function including terms for segmental diffusion, translational diffusion, and reaction diffusion. The model includes chain transfer to monomer and is capable of representing polymer molecular weight averages and distributions, with the better fit obtained assuming that the transfer rate coefficient also varies with monomer concentration."],["dc.identifier.doi","10.1021/ie800887v"],["dc.identifier.isi","000260534600031"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52961"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0888-5885"],["dc.title","Kinetics and Modeling of Free-Radical Batch Polymerization of Nonionized Methacrylic Acid 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","2049"],["dc.bibliographiccitation.issue","21"],["dc.bibliographiccitation.journal","Macromolecular Rapid Communications"],["dc.bibliographiccitation.lastpage","2054"],["dc.bibliographiccitation.volume","28"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Lacik, Igor"],["dc.date.accessioned","2018-11-07T10:57:14Z"],["dc.date.available","2018-11-07T10:57:14Z"],["dc.date.issued","2007"],["dc.description.abstract","In acrylate polymerizations both SPRs and tertiary MCRs occur. Via pulsed laser polymerization, using a wide range of LPRRs, in conjunction with aqueous-phase size-exclusion chromatography the polymerization of 1.35 mol-L-1 acrylic acid in aqueous solution has been investigated at 6 degrees C. The sigmoidal decrease in the apparent propagation rate coefficient, k(p)(app), towards lower LPRRs is in line with recent predictions. At the highest LPRRs, k(p)(app) approaches the rate coefficient of SPR propagation, k(p)(SPR), whereas the limiting value of k(p)(app) at low LPRRs approaches the effective propagation rate coefficient, k(p)(eff), which allows for an estimate of the fraction of MCRs under polymerization conditions, x(MCR). {graphics}"],["dc.identifier.doi","10.1002/marc.200700396"],["dc.identifier.isi","000250902700001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50196"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1022-1336"],["dc.title","Propagation rate coefficient and fraction of mid-chain radicals for acrylic acid polymerization 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","481"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Macromolecules"],["dc.bibliographiccitation.lastpage","488"],["dc.bibliographiccitation.volume","42"],["dc.contributor.author","Barth, Johannes"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Sergeeva, Tatiana"],["dc.date.accessioned","2018-11-07T08:33:26Z"],["dc.date.available","2018-11-07T08:33:26Z"],["dc.date.issued","2009"],["dc.description.abstract","The chain-length dependence of the termination rate coefficient, k(t), of bulk homopolymerizations of n-butyl methacrylate (n-BMA) and tert-butyl methacrylate (t-BMA) at ambient pressure and temperatures between -30 and 60 degrees C has been studied via the single pulse-pulsed laser polymerization-electron spin resonance (SP-PLP-ESR) technique. The decay of radical concentration, c(R), after laser SP initiation is monitored with a high time resolution of microseconds by ESR spectroscopy. Radical chain length, i, increases linearly with time t after applying the laser pulse. The experimental k(t)(i,i) values refer to rate coefficients for termination of two radicals of identical chain length i. The variation of k(t)(i,i) with chain length is adequately represented via the composite model proposed by Smith et al., in which two power-law expressions, k(t)(i-i) proportional to i(-alpha), are contained with the exponents alpha(s) and alpha(l) referring to short-chain and long-chain radicals, respectively. The transition between the two regimes occurs at the crossover chain length, i(c). The rate coefficients extrapolated for termination of two radicals of chain length unity. k(t)(l,l), are almost identical for n-BMA and t-BMA with an activation energy of E-A(k(t)(l,l)) approximate to 10 kJ mol(-1). The alpha(s) values are close to each other 0.65 +/- 0.10 (n-BMA) and 0.56 +/- 0.10 (t-BMA). Both alpha(l) values are found to be 0.20 +/- 0.05, which is close to the theoretical value of alpha(l), = 0.16. The crossover chain lengths are i(c) approximate to 50 for n-BMA and i(c) approximate to 70 for t-BMA. The minor differences in composite-model parameter values of n-BMA and t-BMA are assigned to differences in chain mobility."],["dc.identifier.doi","10.1021/ma802078g"],["dc.identifier.isi","000262625200003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17576"],["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","Chain-Length-Dependent Termination in n-Butyl Methacrylate and tert-Butyl Methacrylate Bulk Homopolymerizations Studied via SP-PLP-ESR"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","8631"],["dc.bibliographiccitation.issue","24"],["dc.bibliographiccitation.journal","Macromolecules"],["dc.bibliographiccitation.lastpage","8641"],["dc.bibliographiccitation.volume","40"],["dc.contributor.author","Nikitin, Anatoly N."],["dc.contributor.author","Hutchinson, Robin A."],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.date.accessioned","2018-11-07T10:51:34Z"],["dc.date.available","2018-11-07T10:51:34Z"],["dc.date.issued","2007"],["dc.description.abstract","A novel method to extract individual free-radical polymerization rate coefficients for butyl acrylate intramolecular chain transfer (backbiting), k(bb), and for monomer addition to the resulting midchain radical, k(p)(t), is presented. The approach for measuring k(bb) does not require knowledge of any other rate coefficient. Only the dispersion parameter of SEC broadening has to be determined by fitting measured MWDs or should be available from separate experiments. The method is based upon analysis of the shift in the position of the inflection point of polymer molecular weight distributions produced by a series of pulsed-laser polymerization (PLP) experiments with varying laser pulse repetition rate. The coefficient k(bb) is determined from the onset of the sharp decrease of the apparent propagation rate coefficient (k(p)(app)) with decreasing repetition rate, an approach verified by simulation. With experiments performed between -10 and +30 degrees C, the estimated values are fitted well by an Arrhenius relation with pre-exponential factor A(k(bb)) = (4.84 +/- 0.29) x 10(7) s(-1) and activation energy E-a(k(bb)) = (31.7 +/- 2.5) kJ center dot mol(-1). At low pulse repetition rates, the experimental k(p)(app) values are related to an averaged propagation rate coefficient, k(p)(av), that is dependent on the relative population of chain-end and midchain radicals. Evaluated by comparing simulated and experimental molecular weight distributions, k(p)(av) provides an estimate for k(p)(t). The Arrhenius parameters are: A(k(p)(t)) = (1.52 +/- 0.14) x 10(6) L center dot mol(-1)center dot s(-1) and E-a(k(p)(t)) = (28.9 +/- 3.2) kJ center dot mol(-1)."],["dc.identifier.doi","10.1021/ma071413o"],["dc.identifier.isi","000251094500022"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48923"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0024-9297"],["dc.title","Determination of intramolecular chain transfer and midchain radical propagation rate coefficients for butyl acrylate by pulsed laser polymerization"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","23"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Macromolecular Chemistry and Physics"],["dc.bibliographiccitation.lastpage","37"],["dc.bibliographiccitation.volume","216"],["dc.contributor.author","Lacik, Igor"],["dc.contributor.author","Stach, Marek"],["dc.contributor.author","Kasak, Peter"],["dc.contributor.author","Semak, Vladislav"],["dc.contributor.author","Uhelska, Lucia"],["dc.contributor.author","Chovancova, Anna"],["dc.contributor.author","Reinhold, Guenter"],["dc.contributor.author","Kilz, Peter"],["dc.contributor.author","Delaittre, Guillaume"],["dc.contributor.author","Charleux, Bernadette"],["dc.contributor.author","Chaduc, Isabelle"],["dc.contributor.author","D'Agosto, Franck"],["dc.contributor.author","Lansalot, Muriel"],["dc.contributor.author","Gaborieau, Marianne"],["dc.contributor.author","Castignolles, Patrice"],["dc.contributor.author","Gilbert, Robert G."],["dc.contributor.author","Szablan, Zachary"],["dc.contributor.author","Barner-Kowollik, Christopher"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Buback, Michael"],["dc.date.accessioned","2018-11-07T10:04:04Z"],["dc.date.available","2018-11-07T10:04:04Z"],["dc.date.issued","2015"],["dc.description.abstract","The accurate characterization of molar-mass distributions of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) by size-exclusion chromatography (SEC) is addressed. Two methods are employed: direct aqueous-phase SEC on P(M)AA and THF-based SEC after esterification of P(M) AA to the associated methyl esters, P(M) MA. P(M) AA calibration standards, P(M) AA samples prepared by pulsed-laser polymerization (PLP), and PAA samples prepared by reversible addition-fragmentation chain transfer (RAFT) are characterized in a joint initiative of seven laboratories, with satisfactory agreement achieved between the institutions. Both SEC methods provide reliable results for PMAA. In the case of PAA, close agreement between the two SEC methods is only observed for samples prepared by RAFT polymerization with weight-average molar mass between 80 000 and 145 000 g mol(-1) and for standards with peak molar masses below 20 000 g mol(-1). For standards with higher molar masses and for PLP-prepared PAA, the values from THF-based SEC are as much as 40% below the molar masses determined by aqueous-phase SEC. This discrepancy may be due to branching or degradation of branched PAA during methylation. While both SEC methods can be recommended for PMAA, aqueous-phase SEC should be used for molar-mass analysis of PAA unless the sample is not branched."],["dc.identifier.doi","10.1002/macp.201400339"],["dc.identifier.isi","000347241500003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38613"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1521-3935"],["dc.relation.issn","1022-1352"],["dc.title","SEC Analysis of Poly(Acrylic Acid) and Poly(Methacrylic Acid)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3513"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Macromolecules"],["dc.bibliographiccitation.lastpage","3520"],["dc.bibliographiccitation.volume","41"],["dc.contributor.author","Beuermann, Sabine"],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Hutchinson, Robin A."],["dc.contributor.author","Kukucova, Silvia"],["dc.contributor.author","Lacik, Igor"],["dc.date.accessioned","2018-11-07T11:15:00Z"],["dc.date.available","2018-11-07T11:15:00Z"],["dc.date.issued","2008"],["dc.description.abstract","The termination kinetics of free-radical polymerization of nonionized methacrylic acid (MAA) in aqueous solution has been investigated at two MAA concentrations, 30 and 60 wt %, by single-pulse pulsed-laser initiated polymerization carried out in conjunction with mu s time-resolved in-line monitoring of monomer conversion via near-infrared spectroscopy (SP-PLP-NIR). From measured values of k(t)/k(p) for 2000 bar, with the conversion-dependent propagation rate coefficient, k(p), being inferred from literature data, the chain-length-averaged termination rate coefficient, < k(t)>, is deduced as a function of monomer conversion, x. As with methyl methacrylate polymerization, the < k(t)> vs x dependence may be modeled under the assumption that, toward higher degrees of monomer conversion, < k(t)> is successively controlled by segmental diffusion, translational diffusion, and reaction diffusion. For 50 degrees C, 2000 bar, and initial monomer concentrations in water of 30 and 60 wt %, chemically initiated polymerizations have also been carried out. The resulting < k(t)> values are in good agreement with the data from SP-PLP-NIR."],["dc.identifier.doi","10.1021/ma7028902"],["dc.identifier.isi","000256058000020"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54273"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0024-9297"],["dc.title","Termination kinetics of the free-radical polymerization of nonionized methacrylic acid 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","5174"],["dc.bibliographiccitation.issue","14"],["dc.bibliographiccitation.journal","Macromolecules"],["dc.bibliographiccitation.lastpage","5185"],["dc.bibliographiccitation.volume","41"],["dc.contributor.author","Stach, Marek"],["dc.contributor.author","Lacik, Igor"],["dc.contributor.author","Chorvat, Dusan, Jr."],["dc.contributor.author","Buback, Michael"],["dc.contributor.author","Hesse, Pascal"],["dc.contributor.author","Hutchinson, Robin A."],["dc.contributor.author","Tang, Lina"],["dc.date.accessioned","2018-11-07T11:12:54Z"],["dc.date.available","2018-11-07T11:12:54Z"],["dc.date.issued","2008"],["dc.description.abstract","Propagation rate coefficients, k(p), of N-vinyl pyrrolidone (NVP) radical polymerization in aqueous solution have been measured via the pulsed-laser polymerization - size exclusion chromatography method (PLP-SEC) over an extended concentration range from 1.8 to 100 wt % NVP at temperatures between 2 and 60 degrees C. The SEC analyses have been carried out by a modified procedure using dimethyl acetamide as the eluent. An about 20-fold increase of k(p) is observed in passing from NVP bulk polymerization to reaction in dilute aqueous solution. As with nonionized methacrylic acid (MAA), for which a similarly strong change in k(p) has recently been reported, the large solvent effect in NVP polymerization is assigned to intermolecular interactions resulting in a significant hindrance of internal rotational motion in the transition state structure for propagation. Some contribution from a minor change in activation energy may however not be ruled out. PLP-SEC studies carried out on aqueous NVP solutions to which either polyNVP or N-ethyl-2-pyrrolidone (NEP), the saturated analogue of NVP, have been added, demonstrate that k(p) depends on the molecular environment at the reactive site, which is affected by NVP (or NEP) content, but not by the polyNVP content. The lowering of monomer concentration during NVP polymerization to higher degrees of monomer conversion results in an increase of k(p). Variation of pH in the range 3 to 10 does not affect k(p)."],["dc.identifier.doi","10.1021/ma800354h"],["dc.identifier.isi","000257665900014"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53769"],["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","Propagation rate coefficient for radical polymerization of N-vinyl pyrrolidone in aqueous solution obtained by PLP-SEC"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]