Study of the microstructure of tetrahydrofuran-3,3 dimethyloxetane copolymers by 13C-NMR spectroscopy.

The microstructure of tetrahydrofuran (A)-3,3 dimethyloxetane (B) copolymers was studied by ¹³C-{¹H}-NMR spectroscopy. Only the methyl carbons corresponding to the 3,3 dimethyloxetane unit appear as a singlet, whereas the other carbons present a more complicated spectral pattern than it would be expected if ? effects were negligible. The assignment of the resonance signals allowed the determination of the values of the probabilities of the different triads, which were in good agreement with those obtained from the reactivity ratios.