Metathesis degradation of partially cyclopropanated 1,4-polybutadiene: Consideration of side reactions in the calculation of block size distribution

(Z)‐1,4‐Polybutadiene was partially cyclopropanated with bis(iodomethyl)zinc and the polymer was degraded with (E)‐4‐octene in the presence of WCl6/(CH3)4Sn as catalyst. The products were identified by gas chromatography/mass spectrometry and determined by gas chromatography. The block size distribution in the partially cyclopropanated polymer was calculated from these products. A method is described by which the decrease in yield of the modified degradation products, caused by side reactions during the olefin metathesis, can be taken into account in this calculation. It is concluded that under the given experimental conditions the block size distribution is random.