Carbon-13 nuclear magnetic relaxations and chain local motions of poly(vinyl chloride) in dibutyl phthalate and tetrachloroethane solutions

Radiotis, T.; Brown, G. R.; Dais, Photis

doi:10.1021/ma00058a039

Cited by 21 publications

(16 citation statements)

References 9 publications

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“…Both T 1 s of the polymer backbone and end group carbons are independent of polymer concentration in the semi‐dilute regime, and decrease with further increased concentration. This concentration dependence is similar to that observed in a previous study on the solutions of poly(vinyl chloride) in tetrachloroethane,21 but opposite to that of the proton T 1 relaxation.…”

Section: Resultssupporting

confidence: 89%

Unexpected proton spin‐lattice relaxation in the solutions of polyolefin and tetrachloroethane

Qiu

Zhou

2010

Magnetic Reson in Chemistry

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'Unexpected' proton spin-lattice relaxation (T(1)) times are reported for the solutions of poly(ethylene-co-1-octene) and tetrachloroethane-d(2). For the residual protons of the deuterated solvent and the methyl and vinyl protons at the polymer chain ends, their T(1) relaxation times vary significantly with both the polymer concentration and molecular weight over a wide range. The T(1)s also decrease with increasing temperature at relative high temperatures. Such behaviors are in contrast to most reported polymer solutions in which the T(1) has nearly no concentration or molecular weight dependence in the dilute and semi-dilute regime, and normal dependence on temperature. Further investigation revealed that the paramagnetic oxygen effect did shorten the measured proton T(1)s, but cannot account for the unexpected T(1) dependences. Spin rotation is proposed to provide a reasonable explanation.

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Section: Resultssupporting

confidence: 89%

Unexpected proton spin‐lattice relaxation in the solutions of polyolefin and tetrachloroethane

Qiu

Zhou

2010

Magnetic Reson in Chemistry

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“…The detailed analysis of relaxation data determined in a number of polymer systems, 9,[15][16][17][18][19][20][21][22] either in solution or in bulk at temperatures well above the glass transition temperature, has shown that the local motions observed by 13 C spinlattice relaxation can be satisfyingly described in terms of damped diffusion of bond orientation along the chain sequence, which represents the segmental motions, and independent fast bond librations. 9 The corresponding orientation autocorrelation function is written as…”

Section: -mentioning

confidence: 99%

Local dynamics of isotactic and syndiotactic polypropylene in solution

Destrée

Lauprêtre

Lyulin

et al. 2000

The Journal of Chemical Physics

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The local dynamics of polypropylene ͑PP͒ in solution is studied by 13 C NMR relaxation and by molecular dynamics ͑MD͒ simulation via the orientational autocorrelation function ͑OACF͒ of C-H bonds. The interpretation protocol of this function proposed by Dejean de la Bâtie, Lauprêtre and Monnerie ͑DLM͒ ͓R. Dejean de la Bâtie, F. Lauprêtre, and L. Monnerie, Macromolecules 21, 2045͑1988͔͒ is applied and tested on new NMR measurements of the various microstructures of polypropylene. This interpretation scheme of the OACF is supported by a detailed study employing simulated PP trajectories in an atomistic heat bath. MD simulations indicate that, quite generally, the correlation time for segmental motions, 1 , extracted from the DLM motional model is closely linked with the mean time between conformational jumps. Both experiments and simulations suggest a slightly higher mobility of meso sequences by comparison with racemic sequences. Our analysis of the microscopic aspects of the segmental dynamics and its manifestation in motional models allows us to trace the microscopic origin of the larger mobility of meso sequences.

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“…Recently Radiotis et al reported NMR relaxation measurements on PVC in two solvents: dibutyl phthalate ( DBP ) and d2-lr 1,2,2-tetrachloroethane (TCE) . 65 Measurements at two Larmor frequencies were fit by the DLM3' model. Application of the high friction Kramers' theory [ eq.…”

Section: Dynamics Of Polyvinylchloride In Dilute Solutionmentioning

confidence: 99%

“…We have found that all the data reported in ref. 65 can be fit to eq. (5) using a single set of parameters: E, = 16.5 kJ/mol, (Y = 0.7.…”

Section: Dynamics Of Polyvinylchloride In Dilute Solutionmentioning

confidence: 99%

Carbon‐13 NMR measurments of polybutadiene local dynamics in dilute solution: Further evidence for non‐Kramers' behavior

Zhu¹,

Gisser²,

Ediger³

1994

J Polym Sci B Polym Phys

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The local segmental dynamics of cis‐polybutadiene in dilute solutions have been investigated using natural abundance 13C NMR spectroscopy. The time integral of the CH orientation autocorrelation function 〈σ〉 is extracted from T1 measurements in five solvents covering a viscosity range of two decades. The hydrodynamic Kramers' equation, which is generally assumed to be appropriate for local polymer dynamics in dilute solution, cannot describe these results. 〈σ〉 is found to depend upon the solvent viscosity η raised to the 0.33 power whether η is varied by changing the temperature or the solvent. This apparent power law behavior has been observed for other polymers in dilute solution and can be rationalized if the solvent is viewed as viscoelastic. This view is supported by experimental results which show that local polymer dynamics can occur as much as an order of magnitude faster than solvent reorientation. Trends for a mixed microstructure polybutadiene are similar to those of cis‐polybutadiene. © 1994 John Wiley & Sons, Inc.

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Carbon-13 nuclear magnetic relaxations and chain local motions of poly(vinyl chloride) in dibutyl phthalate and tetrachloroethane solutions

Cited by 21 publications

References 9 publications

Unexpected proton spin‐lattice relaxation in the solutions of polyolefin and tetrachloroethane

Unexpected proton spin‐lattice relaxation in the solutions of polyolefin and tetrachloroethane

Local dynamics of isotactic and syndiotactic polypropylene in solution

Carbon‐13 NMR measurments of polybutadiene local dynamics in dilute solution: Further evidence for non‐Kramers' behavior

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