Study of thermal decomposition of poly(vinyl chloride) type polymers with the use of model substances—II: Pyrolysis of Trans-1,3-dichloro-1- pentene, Trans-5-chloro-3-heptene, cis-4-chloro-2-pentene and of stereoisomers of 2,4-dichloropentane in the gas phase

✍ Scribed by V. Chytrý; B. Obereigner; D. Lim

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 539 KB
• Volume: 7
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(71)90143-1

✦ Synopsis

The decompositions of the following poly(vinyl chloride) models were investigated in the gas phase: trans-l,3-dichloro-l-pentene (in the range 310-380°), trans-5-chloro-3-heptene (296-357°), cis-4-chloro-2-pentene (295-340 °) and racem, and meso 2,4-dichloropentane at 351 and 370 °. The decomposition processes are homogeneous unimolecular first-order reactions with rate constants 5"76X lOtaexp(--48.5/RT)sec-l,l.41 × 10~3 exp (--43.9/RT)sec-t and 2,76 ~.: 10t2exp(--37-5/ RT) sec -t, respectively. The two 2,4-dichloropentane stereoisomers decompose at the same rate.

From the course of decomposition of models in the gas phase, possible conclusions about decomposition of polymer are drawn. The role of double bonds, their geometric isomerism and configuration of sequences in the macromolecular chains are discussed in connection with elimination of hydrogen chloride from poly(vinyl chloride).