The Microstructure of Poly(Isobutylene-<i>co-p</i>-Methylstyrene) by NMR Spectroscopy

Lubnin, Alexander V.; Országh, I.; Kennedy, Joseph P.

doi:10.1080/10601329508009363

Cited by 11 publications

(8 citation statements)

References 18 publications

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“…It offers a number of advantages over both isobutylene homopolymers and other butyl rubber copolymers, such as higher resistance to degradation and enhanced functionalization ability [15]. IMS structure and composition has been previously reported by NMR, but these studies focused on either IMS made by living carbocationic polymerization [16,17], or on the NMR methodology itself [18]. If IMS oligomers could be sufficiently ionized, MALDI-MS could provide additional insight into the copolymerization reaction, and prove to be a valuable alternate characterization method.…”

mentioning

confidence: 99%

Compositional analysis of isobutylene/p-methylstyrene copolymers by matrix-assisted laser desorption/ionization mass spectrometry

Cox

Johnston

Qian

et al. 2004

J. Am. Soc. Mass Spectrom.

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A low molecular weight predominantly polyolefin copolymer of isobutylene and para methylstyrene (IMS) was studied using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. Average composition information derived from the spectra was skewed to higher para methylstyrene (pMS) content as compared to that obtained using multiple NMR techniques, and drifted towards lower pMS incorporation at higher oligomer lengths. Although both observations were initially attributed in total to an inability to ionize the isobutylene component, comparison with subsequent field desorption (FD) mass spectrometry results gave similar values to that obtained via MALDI, even though FD ionizes oligomers not detected by MALDI. Instead, the compositional drift observed with MALDI roughly mirrored the mass distribution, and was determined to arise from a mass bias effect in oligomer ionization and detection. Composition with respect to oligomer mass was found to be relatively constant, although similarly higher in pMS content. Comparison of experimental peaks with a Bernoullian statistical model revealed severe overrepresentation of higher pMS composition oligomers with regard to the calculated distribution. This discrepancy is attributed to preferential ionization of oligomers with greater pMS content, and likely results in the observed difference between MALDI and NMR compositions.

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mentioning

confidence: 99%

Compositional analysis of isobutylene/p-methylstyrene copolymers by matrix-assisted laser desorption/ionization mass spectrometry

Cox

Johnston

Qian

et al. 2004

J. Am. Soc. Mass Spectrom.

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“…The spatial coupling between the methylene dyads SS and MS with the phenylic protons was observed and it was assigned to SSrSS (7), SSrSM (8), and MSrSM (9) tetrads for the coupling with SS at ␦1.4/6.88, ␦1.45/7.1, and ␦1.58/7.15 ppm, respectively. The SMmSS (10), SMmSM (11), and MMmSM (12) tetrads for the spatial coupling of the MS dyad with styrene protons at ␦1.6/6.92, ␦1.85/7.2, and ␦1.9/6.8 ppm were assigned.…”

Section: D-nmr Studiesmentioning

confidence: 99%

Characterization of styrene/methacrylic acid copolymers by 2D‐NMR spectroscopy

Brar

Hekmatyar

2001

J of Applied Polymer Sci

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Styrene/methacrylic acid copolymers were prepared by free-radical photopolymerization using the uranyl nitrate ion as the initiator. The copolymer composition was determined from 1 H-NMR spectroscopy. The comonomer reactivity ratios determined using Kelen Tudos and nonlinear error in variable methods (EVM) are r m ϭ 0.61 Ϯ 0.05 and r s ϭ 0.14Ϯ 0.07. The broad and overlapping 1 H-NMR spectrum was assigned using the help of 2D TOCSY and NOESY experiments. These methods were used to ascertain the various geminal, vicinal, and spatial couplings between the protons. The methyl and methine protons also show configurational and compositional sensitivity.

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“…The NMR analysis of polyisobutylenes with end groups of various nature has been extensively described [16][17][18][19]. The NMR analysis of polyisobutylenes with end groups of various nature has been extensively described [16][17][18][19].…”

Section: Mn Mnmentioning

confidence: 99%

LIVING CARBOCATIONIC OLIGOMERIZATION OF ISOBUTYLENE BY TERTIARY ALCOHOL/BCl₃/1-METHYL- 2-PYRROLIDINONE INITIATING SYSTEMS. KINETIC STUDY

Rodrigues

Tessier

Maréchal

1999

Journal of Macromolecular Science, Part A

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Low molar mass (Mn Ñ < 4000 g.mol -1 ), narrow molar mass distribution (Mw Ñ /Mn Ñ =1.1-1.3) linear α-(tert-butyl) ω-(tert-chloro) and α-cumyl ω-(tert-chloro) oligoisobutylenes (PIBs) were synthesized using two initiating systems: 2,4,4-trimethyl-pentan-2ol (TMPOH)/BCl 3 /-40¡C and 2-phenylpropan-2-ol (CumOH)/-BCl 3 /-70¡C in the presence of an efficient electron-pair donor (ED), 1-methyl-2-pyrrolidinone (NMP) in methyl chloride. The kinetics of oligomerization were investigated. In these two systems, similar polymerization mechanisms were observed with, nevertheless, a slight difference of growing species behavior in the early polymerization steps. The initiation and propagation rate constants were determined; their values are low showing that the addition of NMP to these initiating systems leads to controlled carbocationic polymerizations. Moreover, the living character of the polymerization was demonstrated.

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The Microstructure of Poly(Isobutylene-co-p-Methylstyrene) by NMR Spectroscopy

Cited by 11 publications

References 18 publications

Compositional analysis of isobutylene/p-methylstyrene copolymers by matrix-assisted laser desorption/ionization mass spectrometry

Compositional analysis of isobutylene/p-methylstyrene copolymers by matrix-assisted laser desorption/ionization mass spectrometry

Characterization of styrene/methacrylic acid copolymers by 2D‐NMR spectroscopy

LIVING CARBOCATIONIC OLIGOMERIZATION OF ISOBUTYLENE BY TERTIARY ALCOHOL/BCl₃/1-METHYL- 2-PYRROLIDINONE INITIATING SYSTEMS. KINETIC STUDY

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The Microstructure of Poly(Isobutylene-co-p-Methylstyrene) by NMR Spectroscopy

Cited by 11 publications

References 18 publications

Compositional analysis of isobutylene/p-methylstyrene copolymers by matrix-assisted laser desorption/ionization mass spectrometry

Compositional analysis of isobutylene/p-methylstyrene copolymers by matrix-assisted laser desorption/ionization mass spectrometry

Characterization of styrene/methacrylic acid copolymers by 2D‐NMR spectroscopy

LIVING CARBOCATIONIC OLIGOMERIZATION OF ISOBUTYLENE BY TERTIARY ALCOHOL/BCl3/1-METHYL- 2-PYRROLIDINONE INITIATING SYSTEMS. KINETIC STUDY

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LIVING CARBOCATIONIC OLIGOMERIZATION OF ISOBUTYLENE BY TERTIARY ALCOHOL/BCl₃/1-METHYL- 2-PYRROLIDINONE INITIATING SYSTEMS. KINETIC STUDY