Alex Lubnin - Comprehensive Assignments of 1H and 13C NMR Signals of End-Functional Polyisobutylenes Using Spin-Lattice Relaxation Times and 2D 1H-13C HETCOR Spectroscopy

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      Publication Details (including relevant citation   information):

    Journal of Macromolecular Science - Pure and Applied Chemistry, Vol. A32, No. 2,   pp. 191-209 (1995)


      The 13C spin-lattice relaxation times (T1's) of polyisobutylenes   (PIBs) bearing tert-Bu, tert-chloride, exo-olefin, alc.,   aldehyde, and acetal end groups have been detd., and all the   signals in their 13C-NMR spectra were assigned according to the   gradient of T1 along the polymer chain with the min. in the   middle.  13C T1 anal. has also been used to obtain   assignments for internal polyisobutylene segments adjacent to   arom. initiator residues.  The method provides insight into   the interaction of hydroxyl end groups of alc.-capped PIBs, and   allows identification of the low mol. wt. impurities in the   polymers.  Assignments of all the 1H NMR signals of the   above polyisobutylenes were obtained by 2D 1H-13C HETCOR   spectroscopy.  For some polymers, 1H-NMR signals were also   assigned based on their 1H T1 values and the assignments agree   with those generated by HETCOR spectroscopy.

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