Polyisoprene

Both synthetic polyisoprene and natural rubber are highly elastic and consequently used to make tires and a variety of other applications.

[citation needed] Anionic chain polymerization, which is initiated by n-Butyllithium, produces cis-1,4-polyisoprene dominant polyisoprene.

[3] Coordinative chain polymerization: With Ziegler–Natta catalyst TiCl4/Al(i-C4H9)3, a more pure cis-1,4-polyisoprene similar to natural rubber is formed.

[4] 1,2 and 3,4 dominant polyisoprene is produced MoO2Cl2 catalyst supported by phosphorus ligand and Al(OPhCH3)(i-Bu)2 co-catalyst.

[6] In 1962, Goodyear succeeded in making a 98.5% cis polymer using a Ziegler-Natta catalyst, and this went on to commercial success.