Kinetics Study on Polyether Bulk End-cross-linking CuAAC Reaction

In order to study the kinetic characters of bulk end-cross-linking CuAAC click reaction, in situ FTIR method was employed to investigate the kinetics of PTPEG/GAP bulk end-cross-linking CuAAC click reaction based on the spectral character of PTPEG and GAP. The kinetics curves of PTPEG/GAP bulk end-cross-linking CuAAC click reaction were obtained on the basis of the relationship of the absorbance ratio at 2100 cm^-1and 1086 cm^-1changing with time. The results of fitting curves indicated that during the whole reaction, two obvious stages were observed. At 30 ℃, 40 ℃, 50 ℃ and 60 ℃, the first stage ended at 535 min, 305 min, 295 min and 115 min, respectively. Shear viscosity (η) results showed that the curves of changed along with reaction time showed an L-like shape. At 30 ℃, 40 ℃, 50 ℃ and 60 ℃, the inflection point of η-t curves appeared at 540 min, 320 min,305 min and 118 min, respectively. The inflection point time of η-t curves was consistent with the end time of first stage of the PTPEG/GAP. Arrhenius equation fitting results indicated that the activation energy of the first stage corresponding to the reaction before gelation of PTPEG/GAP was (45.57±2.77)kJ/mol while that of the second stage corresponding to the reaction after gelation was (59.50±4.01)kJ/mol.