1,2-dinitrile polymers. III. Number-average molecular weight by pulsed NMR technique

In studies of various polymers in the solid state by pulsed and wide-line NMR, a relationship between the spin-lattice relaxation time and the fraction of mobile protons in the polymer sample was observed. This effect has been used to determine the degree of polymerization of a series of fumaronitrile homopolymers. The technique should have wide applicability in the direct determination of the number-average molecular weight M?_n, especially for polymers that may be insoluble and/or infusible though not crosslinked.