正子湮滅光譜與Bondi理論評估高分子摻合薄膜自由體積之研究

Study on free volume estimation of blend polymeric membranes by Bondi method and positron annihilation spectroscopy

陳群傑(Chun-Chieh Chen)

指導教授 ： ARRAY(0xa3f1864)

中原大學/工學院/化學工程研究所/碩士(2010年)

https://doi.org/10.6840/cycu201000248

摘要

本研究製備相容(Polystyrene/Poly(2,6-dimethyl-p- phenylene oxide))(PS/PPO)和不相容(Poly(bisphenol A-co-4-nitriphthalic anhydride-co-1,3- phenylenediamine)/Polysulfone)(PEI/PSf)摻合薄膜，使用不同之理論與實測方法，探討摻合薄膜之自由體積與氣體分離的相關性，評估Bondi理論估算摻合薄膜自由體積之正確性，同時推導出可正確估算摻合薄膜自由體積之經驗方程式。
SEM和DSC的結果顯示PEI/PSf為不相容摻合薄膜，並且EDX證明在PSf含量為40、50及60wt%時，PEI為非連續相。氣體透過係數隨著PSf的含量增加而提升，Bondi估算所得之自由體積變化與氣體透過不符。但由PALS所計算之自由體積分率變動趨勢與氣體透過係數變化相同，由此可知Bondi理論並不適用於估算不相容摻合薄膜之自由體積。
SEM結果發現PS/PPO摻合薄膜的截面為均相，且DSC結果呈現單一玻璃轉移溫度(Tg)，證明PS/PPO摻合薄膜為相容摻合。相容摻合薄膜密度隨著PPO添加而增加，在PPO含量50wt%時有最大的密度。由Bondi估算和PALS計算的自由體積分率隨著PPO的添加均有先下降後上升的趨勢，自由體積變化趨勢與氣體分離行為有顯著差異，此一現象歸因於自由體積尺寸隨著PPO的添加增加而增加，但自由體積數量隨著PPO的添加有先下降後上升的趨勢。

關鍵字

高分子摻和 ； 正子湮滅光譜 ； 氣體透過 ； 自由體積

並列摘要

In this study, we prepared miscible polystyrene/ poly(2,6-dimethyl-p- phenylene oxide (PS/PPO) and immiscible poly(bisphenol A-co-4-nitriphthalic anhydride-co-1,3- phenylenediamine)/polysulfone (PEI/PSf) blend membranes and used various theories and methods of measurements to investigate the correlation between free volume in blend membranes and gas separation and to evaluate Bondi theory of estimating free volume in blend membranes, at the same time derive a correct equation for free volume in blend membranes.
SEM and DSC results showed PEI/PSf as immiscible blend membranes, and EDX confirmed PEI as a non-continuous phase at PSf contents of 40, 50, and 60 wt%. Gas permeability increased with the PSf content, and Bondi estimate of change in free volume and gas permeability were inconsistent. However, trends in the resulting changes in fractional free volume calculated from PALS and the changes in gas permeability coefficient were identical. From this information, Bondi theory is not applicable for estimating free volume in immiscible blend membranes.
SEM results show PS/PPO blend membrane cross-section as homogeneous, and DSC results present single glass transition temperature (Tg), verifying PS/PPO blend membrane as miscible. Miscible blend membrane density increased with PPO, and there was a maximum density at PPO content of 50 wt%. From Bondi estimation and PALS calculation, fractional free volume first decreased and then increased with increase in PPO, and free volume change tendency and gas separation behavior were significantly different, and this phenomenon is attributed to increase in the free volume-size with PPO addition; however, the free-volume intensity had the tendency to decrease first and to increase afterward.

並列關鍵字

free volume ； gas permeabilty ； polymer blend ； positron annihilation spectroscopy

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