PolyPB, PolyNB and PolyPnB synthesized by a radical initiator have no 1,2-units, as evidenced by the absence of the absorptions at 990 and 910$cm^{-1}$ in the IR spectra. PolyPB showed about 33% of 3,4-unit estimated from the intensities of the olefin protons' resonance of 3,4-unit(6.15 and 5.85ppm) and 1,4-unit(5.40 and 5.22ppm). PolyNB showed a little content of 3,4-uni and PolyPnB showed almost nO 3,4-unit. The ratios of cis-1,4-units and trans-1,4-units of PolyPB, PolyNB and PolyPnB calculated from the intensities of the methine protons' resonances were 0.13, 0.90 and 0.36 respectively.
Cis-trans isomerization reaction caused to decrease the contents of 3,4-units of PolyPB and PolyNB and by this reaction the content of cis-1,4-unit of PolyPB increased slightly but that of PolyNB and PolyPnB showed slight increases which were originated by the high contents of cis-units of those polymers, or by the effect of bulky pendant groups.
H-PolyPB had slight syndiotacticity, but both of H-PolyNB and H-PolyPnB were slightly isotactic with respect to the splitting patterns of the aromatic C1 carbons at 146.34, 142.15 and 140.68ppm respectively in $^{13}C-NMR$ spectra.
