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Updated: Aug 16, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Solid-state NMR and the thermal polymerization of 2,4-hexadiyne-1,6-diol bis-(p-toluenesulfonate)
Jeffrey M Njus1, Daniel J Sandman
1Center for Advanced Materials, Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854-5046, USA. jeffreynjus@yahoo.com
Abstract:
The solid-state thermal polymerization of crystalline 2,4-hexadiyne-1,6-diol bis-(p-toluenesulfonate) (PTS) was investigated by solid-state 13C NMR, the first application of this technique to such a process. The kinetics of the thermal process was examined at temperatures of 40.5, 51.0, and 59.5 degrees C, with a magic angle spinning (MAS) rate of 5 kHz. The first-order rate constants associated with the induction (k0) and autocatalytic (k max) periods were calculated by monitoring signal intensities (conversion) throughout the course of the thermal polymerization. While estimations of the activation energy (E(a) approximately 20 kcal/mol) from the NMR experiments are similar to values obtained by other analytical techniques, estimations of the autocatalytic effect (k max/k0 approximately 22) were significantly lower. Likely causes for the unusually small autocatalytic effect are discussed.
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