How does cross-linking affect the thermal stability of polyisoprene?

Polyisoprene can be cross-linked by an initial lithiation followed by react ion with both monochloro compounds and dichloro compounds. The monochloro c ompounds effect crosslinking through a lithium-chlorine exchange route whil e the use of dichloro compounds links the PIP chains with the spacer betwee n the two chlorine atoms. A significant amount of char is produced from com pounds which have been cross-linked with aromatic dihalides while aliphatic dihalides do not produce significant char. (C) 2000 Elsevier Science Ltd. All rights reserved.