Polyisoprene is a collective name for polymers that are produced by polymerization of isoprene. In principle, four different isomers can form. Cis-1,4-polyisoprene, which is also called isoprene rubber, is a major ingredient of natural rubber. Trans-1,4-polyisoprene is a major ingredient of gutta-percha. Annual worldwide production of polyisoprene was 13,000 kilotonne in 2007.
This section may be too technical for most readers to understand. Please help improve it to make it understandable to non-experts, without removing the technical details. (October 2018) (Learn how and when to remove this template message)
The percentage of repeating units of polyisoprene comprising each type of polymer bond is dependent on the reaction mechanism.
Coordinative chain polymerization: With Ziegler–Natta catalyst TiCl4/Al(i-C4H9)3, more pure Cis-1,4-polyisoprene is formed. Natural rubber is more pure cis-1,4-polyisoprene. With Ziegler–Natta catalyst VCl3/Al(i-C4H9)3, trans-dominant polyisoprene is formed.
1,2 and 3,4 dominant polyisoprene is produced MoO2Cl2 catalyst supported by phosphorus ligand and Al(OPhCH3)(i-Bu)2 co-catalyst.
- Sebastian Koltzenburg, Michael Maskos, Oskar Nuyken, Polymere: Synthese, Eigenschaften und Anwendungen, Springer, Berlin, 2012, S. 424.
- Jürgen Falbe, Manfred Regitz (Hrsg.): CD Römpp Chemie Lexikon, Thieme, Stuttgart, 1995.
- Bernd Tieke, Makromolekulare Chemie, 3. Auflage, Wiley-VCH, Weinheim, 2014, S. 149.
- 1,2- and 3,4-rich polyisoprene synthesized by Mo(VI)-based catalyst with phosphorus ligand Polymer Science Series B September 2016, Volume 58, Issue 5, pp 495–502