New structures from the thermal rearrangement of polybutadiene revealed by 2D HSQC NMR

The thermal reactions of polybutadiene (PB) at 260 °C in inert atmosphere were followed by 1H and 13C NMR spectroscopy. Within 24 h of heating, the change in the intensities of some peaks and the appearance of new peaks of NMR spectra permits to follow the reactions occurring in polybutadiene. The sample, after heating for 6 h, was then characterized by a two dimensional HSQC NMR spectrum, showing the appearance of CH3CH moiety, and the migration of double bond in polybutadiene. From these results the new mechanism of intra/intermolecular reactions was proposed.