| Summary: | 碩士 === 國立臺北科技大學 === 化學工程系碩士班 === 91 === First, we use differential scanning calorimeter (DSC) to analyze the crystalline phase transition temperature of syndiotactic polystyrene (sPS), and then use wide angle x-ray diffraction (WAXD) to study the morphology of sPS.
We use Hoffman-Weeks equation to analyze the datas that obtained from DSC, when the heating rate is 10℃/min, theα-form shows an endothermic absorption peak at 196℃, while the endothermic absorption peak temperature ofβ-form is 273℃. When heating rate keeps at 20℃/min, the endothermic absorption peak temperatures ofα-form is 199.1℃ andβ-form is 275.2℃. Those values are depondent on the heating rate in the experiment process. It is not a constant.
Results from thermogravimetric analysis under air and nitrogen flow indicate that sPS is more stable than PS and degrades at a higher temperature than PS. Activation energies of thermal degradation of PS and sPS are calculated from Ozawa and Kissinger methods. Activation energy of thermal degradation of sPS, under nitrogen and air atmosphere, is slight higher than that of PS.
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