| Summary: | 碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 105 === A series of blocked isocyanate and polyurethane prepolymers, based on 3,5-dimethylpyrazole and using Sodium Bisulfite as blocked agent were prepared, Blocked-isophorone diisocyanate and polyurethane prepolymer including polyethylene glycol were synthesized and characterized by Fourier transform infrared spectroscopy , respectively. The deblocked temperature of the blocked isocyanate and prepolymer was investigated using thermo-gravimetric analysis. Using differential scanning calorimetry analysis and Kissinger Equation and Crane Equation , the thermal decomposition reaction kinetics were studied. Blocked-polyurethane prepolymer at different molecular weight polyethylene glycol were synthesized. It was found that the deblocked temperature were at 86.5℃ and 82.7℃, respectively. The calculated activation energy were 944.5 and 1830.7 kJ/mol, respectively. The reaction order were 0.83 and 0.88, respectively. With the increasing molecular weight of polyethylene glycol, deblocked temperature, activation energy and reaction order decreased. All of the blocked polyurethane prepolymer decomposing order was not an exact integer because of the presence of side reactions of isocyanate. The water soluble blocked polyurethane prepolymer present in the polymerization of polyaniline was used as the curing agent of epoxy resin.
|
|---|
