Document Type
Article
Publication Date
4-1-2000
Source Publication
Polymer Degradation and Stability
Source ISSN
0141-3910
Abstract
Polyisoprene and polychloroprene have been cross-linked either in solution or in solid state using free radical initiators. In the comparable experimental conditions higher cross-linking density was observed in the solid state process. Independent of the cross-linking method, polychloroprene tended to give a higher gel content and cross-link density than does polyisoprene. Infrared characterization of the cross-linked materials showed cis-trans isomerization occurred in the polyisoprene initiated by benzoyl peroxide, whereas no isomerization was found in the samples initiated by dicumyl peroxide. Polyisoprene does not cross-link by heating in a thermal analyzer, whereas polychloroprene easily undergoes cross-linking in such conditions. Infrared spectroscopy showed that in the case of polyisoprene, rearrangements occur upon heating which lead to the formation of terminal double bonds, while polychloroprene loses hydrogen chlorine which leads to a conjugated structure. There is apparently some enhancement of the thermal and thermal oxidative stability of polyisoprene because of the cross-linking. Cross-linked polychloroprene is less thermally stable than the virgin polymer. Cross-linking promotes polymers charring in the main step of weight loss in air, which leads to enhanced transitory char.
Recommended Citation
Jiang, David D.; Levchik, Galina F.; Levchik, Sergei V.; Dick, Caroline; Liggat, John J.; Snape, C.E.; and Wilkie, Charles A., "Thermal degradation of Cross-Linked Polyisoprene and Polychloroprene" (2000). Chemistry Faculty Research and Publications. 161.
https://epublications.marquette.edu/chem_fac/161
Comments
Accepted version. Polymer Degradation and Stability, Vol. 68, No. 1 (April 1, 2000): 75-82. DOI. © 2000 Elsevier B.V. Used with permission.