The degradation and stabilization of polyacrylonitrile. I. Evidence for β‐ketonitrile defect structures as initiators of degradation

Abstract

SynopsisThe theory that j3-ketonitrile structures initiate discoloration reactions in polyacrylonitrile has been tested by a number of methods. Using radiochemical techniques the numbers of carbonyl groups in various polymers have been measured as have the amounts of combined water. A model j3-keto compound, 1,3,7,-tricyanoheptan-4-one was synthesized and its reactions studied. None of these experiments supported the idea that j3-ketonitrile structures are of primary importance in initiating the degradation of polyacrylonitrile.

Effects of Various Transition Metals on the Thermal Oxidative Stabilization of Polyacrylonitrile Nanofibers

“…[14,[16][17][18] Unfortunately, it also decreased the cyclization rate, generating many beta-amino groups and conjugated nitrile groups, which caused point defects in the carbon fiber. [19,20] Moskowitz et. reported GIA contained copolymers showed a significant reduction in heat flow and cyclization peak temperature as compare to IA copolymers.…”