Summary: | 碩士 === 國立成功大學 === 化學工程學系 === 89 === Abstract
Miscibility and morphology of Poly(2-dimethyl-p-phenylene oxide)/Poly(-methylstyrene)(PPO/PMS)、Poly(26-dimethyl-p-phenylene oxide)/Poly(4-methylstyrene)(PPO/P4MS)and Poly(26-dimethyl-p-phenylene oxide) /Poly(4-methylstyrene)/ Polystyrene(PPO/P4MS/PS)blends were investigated by using differential scanning calorimeter (DSC), polarized-light microscopy (POM), and scanning electron microscopy (SEM) in this study.
The PPO/PMS blend is a miscible system at ambient temperature, which, however, turns into an immiscible phase at higher temperatures. Lower critical solution temperature (LCST) behavior is found in PPO/PMS blend system. Complexity of phase behavior in the PPO/P4MS system has caused puzzling analyses in the past years. This study re-investigated and clarified past mis-interpretations related to this interesting blend system. Upper critical solution temperature (UCST) behavior was found in the blend comprising PPO/P4MS. This study concluded that the PPO/P4MS blend is an immiscible system at ambient temperature, which, however, turns into a miscible phase with UCST behavior at higher temperatures. Upper critical solution temperature (UCST) behavior in a ternary blend of PPO/P4MS/PS is also reported. The as-cast ternary blend is immiscible as ambient, which however, turns into a miscible system above the “clarity point” ranging from 160~290oC for different ternary compositions. The maximum clarity point is labeled as the UCST for the ternary system, which is about 287oC.
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