Thermal Decomposition of Azo Groups of Polyamide 6 Radical Initiator

• Published in: KOBUNSHI RONBUNSHU 1999/09/25, Vol.56(9), pp.557-564
• Main Authors: HIRANO, Tetsuji, FUJII, Takamasa, AMANO, Ryotaro, ONIMURA, Kenjiro, TSUTSUMI, Hiromori, OISHI, Tsutomu
• Format: Article
• Language: Japanese
• Subjects: Azo Group; Differential Scanning Calorimetry; Polyamide 6; Radical Initiator; Thermal Decomposition; Ultraviolet Measurement
• ISSN: 0386-2186; 1881-5685
• DOI: 10.1295/koron.56.557

Thermal decomposition of azo groups of polyamide 6 radical initiators (PA6ini) with molecular weights (Mn) of 5×103 (PA6ini-1) and 13×103 (PA6ini-2), which were obtained from a polyamide 6 prepolymer and 4, 4′-azobis (4-cyanopentanoyl chloride), was measured by differential scanning calorimetry (DSC) and ultraviolet (UV) absorption in solid state and in solution (formic acid and 2, 2, 2-trifluoroethanol), respectively. Thermal decomposition of PA6ini in solid state initiated at a lower temperature than that of 4, 4′-azobis (4-cyanopentanonic acid) (ACPA), and the peak top temperature of PA6ini decreased with increasing molecular weight. Activation energies of azo group decomposition of PA6ini-1 and PA6ini-2 in solid state were 102.3 kJ mol-1 and 88.9 kJ mol-1, respectively. The rate constants of azo group decomposition of ACPA and PA6ini were affected by solvents. The rate constant of azo group decomposition of PA6ini-2 in 2, 2, 2-trifluoroethanol was significantly influenced by concentrations of PA6ini. Activation energies of azo group decomposition of PA6ini were independent of solvents, and were similar to those in solid state.