Thermal decomposition and kinetics studies on poly(BDFAO/THF), poly(DFAMO/THF), and poly(BDFAO/DFAMO/THF)

Poly(3,3-bis(difluoroaminomethyl)oxetane/tetrahydrofuran), poly(3-difluoroaminomethyl-3-methyloxetane/tetrahydrofuran), and poly(3,3-bis(difluoroaminomethyl)oxetane/3-difluoroaminomethyl-3-methyloxetane/tetrahydrofuran) were synthesized via cationic bulk polymerization using boron trifluoride etherate/polyol mixture as catalyst system. Thermal decomposition behaviors of these polymers were investigated by thermogravimetric analysis/differential scanning calorimetry. Kinetics of thermolysis was studied by a model-free method. All of these polymers exhibited a two-stage mass-loss process. The elimination of HF with the activation energy at 95-110 kJ mol(-1) dominated the first stage, while the second stage contained the thermolysis of the remaining polymer chain with monofluoroimino and cyano groups. Fourier transform infra red spectra of the degradation residues showed that the difluoroamino groups decomposed in a two-step HF loss at different temperatures. The existence of monofluoroimino groups was responsible for the two-stage thermolysis process.