NMR (Nuclear Magnetic Resonance) and Macromolecular Migration in a Melt or in Concentrated Solutions,

Abstract

The purpose of this paper is to analyse the migration process of long polymer molecules in a melt or in concentrated solutions as it may be observed from the dynamics of the transverse magnetization of nuclear spins linked to these chains. The low frequency viscoelastic relaxation of polymer systems is known to be mainly controlled by the mechanism of dissociation of topological constraints excited on chains and which are called entanglements. This mechanism exhibits a strong dependence upon the chain molecular weight. These topological constraints also govern the diffusion process of polymer chains. So, the accurate description of the diffusion motion of a chain may be a convenient way to characterize disentanglement processes necessarily involved in any model proposed to explain viscoelastic effects.

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1983
Accession Number
ADP003908

Entities

People

  • J. P. C. Addad

Tags

DTIC Thesaurus Topics

  • Diffusion
  • Frequency
  • Magnetic Resonance
  • Migration
  • Molecular Weight
  • Nuclear Magnetic Resonance
  • Nuclear Spins
  • Quantum Properties
  • Radio Frequency
  • Resonance
  • Resonant Frequency

Fields of Study

  • Physics

Readers

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  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.
  • Theoretical Analysis.