Metathesis Degradation of Partially Hydrogenated cis-l,4-Polybutadiene with Ethylene

Butadiene was polymerized with a catalyst system composed of NdCl₃ tetrahydrofuran complex and AlEt₃. The cis-1,4-polymer produced was partially hydrogenated with Wilkinson's catalyst (RhCl(PPh₃)₃/PPh₃). The hydrogenated polymers were then brought into contact with a large amount of ethylene in the presence of a WCl₆-based metathesis catalyst to obtain α,ω-divinyl polyethylene-like oligomers. Both the hydrogenated polybutadiene and final oligomers were analyzed in some detail by ¹H NMR, ¹³C NMR, DSC, and GPC. The mechanisms of partial hydrogenation and metathesis degradation were discussed on the basis of these analytical results.