Polymer reactions—X thermal pyrolysis of poly(isoprene)

✍ Scribed by J.C.W. Chien; J.K.Y. Kiang

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 457 KB
• Volume: 15
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(79)90146-0

✦ Synopsis

Poly0soprene) (97Vo cis-l,4 and 3Vo 3,4) has been pyrolysed in a carrier stream of helium from 315 to 384 ° . The products were online identified and quantitatively analysed by an interfaced pyrolysis GC peak identification system. The first order rate constant for pyrolysis is 1.1 x 10 -2 sec-t at 384 ° with an overall activation energy of 41 kcal mol-t. The main products are isoprene and l-methyl-4-isopropenyl cyclohexene. The dominant initiation process has been shown to be ~ chain scission leading to two allylic radicals. The former product is derived from an unzipping reaction, the latter together with 1,5-dimethyl-5-vinylcyclohexene are the main Cto products from the allylic radicals. All the other minor products can be account for by simple chain propagation reactions with or without intramolecular hydrogen transfers.