Synthesis of vinyl‐terminated isotactic poly(propylene)

Isotactic poly(propylene)s with 60–80% vinyl chain‐end selectivity were synthesized with metallocene catalysts. Some of these vinyl‐terminated poly(propylene)s are highly stereoregular (mmmm pentads up to 95%) and have high crystalline melting points in the range of 140–150°C. Chain‐end analysis using ¹³C NMR indicates the vinyl chain‐ends in the polymer are most likely formed through β‐methyl elimination in the chain termination step.