Mechanism and Kinetics of Stabilization Reactions of Polyacrylonitrile and Related Copolymers IV. Effects of Atmosphere on Isothermal DSC Thermograms and FT-IR Spectral Changes during Stabilization Reaction of Acrylonitrile/Methacrylic Acid Copolymer

Abstract

Structure formation during the stabilization reactions of the acrylonitrile/methacrylic acid (AN/MAA) copolymer under air, O2 and N2 was studied by an organized combination of isothermal DSC thermograms and FT-IR spectra. Under the oxidative atmosphere evolved heat was very large and the conjugated cyclic structure was formed as a stable structure. Particularly in pure O2 gas the stabilization reaction attained to the most advanced state. Under N2 the evolved heat was smallest and the resulted structure was thought to be a non-conjugated cyclic imine-enamine tautomerism structure.