Pyrolysis of polyacrylonitrile and related polymers—V. Thermal analysis of α-substituted acrylonitrile polymers

✍ Scribed by N. Grassie; R. McGuchan

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 597 KB
• Volume: 8
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(72)90031-6

✦ Synopsis

Comparison of the thermal behaviour of polyacrylonitrile with that of a-substituted polymers (polymethacrylonitrile, poly(a-phenyl acrylonitrile), poly(a-chloroacrylonitril¢) and poly(vinylidene cyanide)) shows that there is much less tendency for oligomerization of the nitrile groups in the substituted polymers. The preferred degradation process in the methyl, phenyl, and cyanosubstituted polymers is depolymerization to monomer but some nitrile rearrangement can be induced by using suitable initiators. In the chlorinated analogue, dehydrochlorination tends to obscure the reactions of the nitrile substituents but a limited amount of nitrile reaction is suggested by the exothermic DTA characteristics. The observed behaviours are consistent with the concept that the a-hydrogen atom in polyacrylonitrile plays an important part in the chain process involved in the oligomerization of nitrile groups.