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Updated: Aug 29, 2026

The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry
Published on: August 25, 2016
NMR relaxation dispersion of vulcanized natural rubber
Sobiroh Kariyo1, Siegfried Stapf
1Lehrstuhl für Makromolekulare Chemie and Magnetic Resonance Center MARC, ITMC, RWTH Aachen, Worringerweg 1, D-52074 Aachen, Germany.
Abstract:
The dependence of the 1H spin-lattice relaxation time on the magnetic field strength has been determined for linear and cross-linked polyisoprene for Larmor frequencies between 5 kHz and 20 MHz. Universal power-law relations are found for all temperatures and cross-link densities under investigation and are compared to published results of rotating-frame experiments on similar natural rubber samples. The shape of the individual dispersion functions can be superposed into a master curve using appropriate shift factors. While addition of filler particles even at large weight fractions has only a minor effect on the relaxation times, uniaxial deformation and swelling are demonstrated to alter the molecular dynamics significantly.
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