合成五碳環中間體應用於聚醯亞胺氣體分離薄膜

Synthesis of Cycloaliphatic Cardo-type Intermediates and polyimide with gas separation membranes

黃雅琴(Ya-Chin Huang)

指導教授 ： 鄭如忠

國立臺灣大學/工學院/高分子科學與工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201802351

摘要

本論文由石油烴高溫裂解製造乙烯過程中副産之五碳烯烴餾分-雙環戊二烯(dicyclopentadiene, DCPD)出發，成功開發出含cardo 結構之二胺單體，並聚合為高分子聚合物。由dicyclopentadiene降解後的中間產物cyclopentadiene (CPD)進行烷基化及觸媒異構化後可進一步形成具有單一反應位置之4-cyclopentenyl phenol (CPP)利用苯酚將其再次烷基化後可得到具有cardo結構之雙酚中間體(CPDP)，透過使用觸媒與烷基化等工業化學反應，改善過去以環戊酮為原料的路徑，反應條件相對較為溫和且可縮短反應時間。利用CPDP與對氟硝基苯或5-氟-2-硝基苯酚反應，並再進行進一步氫化後，可得到含cardo結構之二胺單體C1或同時含cardo結構及鄰位羥基之二胺單體C2，再將C1或C2分別搭配不同之二酸酐單體，合成一系列具cardo結構之聚醯胺酸(cardo polyamic acid, CPAA)，最後使用直接加熱法將CPAA醯亞胺化並製成聚醯亞胺薄膜(cardo polyimides, CPIs)，而由C2及4,4'-(Hexafluoroisopropylidene)diphthalic anhydride (6FDA)聚合而成的CPI-4，會因在醯亞胺基團的鄰位含有羥基，可進一步進行熱重排反應，轉變為聚苯噁唑(polybenzoxazole, PBO)。
本研究合成之含cardo結構CPIs具有優異熱性質，其玻璃轉移溫度(glass transition temperature, Tg)落於244-313℃間。此外，由TGA觀察到CPI-4之熱重排發生於315-360 ℃間，其餘CPIs之熱裂解溫度皆在450℃以上，展現極佳熱穩定性。具有五碳環狀cardo側鏈的CPIs，經由WAXD證實導入cardo側鏈結構可幫助減少高分子鏈段分子間堆疊，故相較於傳統之芳香族聚醯亞胺，CPIs具有較佳的有機溶劑溶解度。同時，也在氣體滲透率分析儀(GPA)觀察到由C1 及6FDA聚合而成的CPI-3擁有相較於市售聚醯亞胺更高的氣體滲透率，且CO2/CH4達46，更具應用於二氧化碳分離程序之發展潛力。

關鍵字

雙環戊二烯；聚醯亞胺；氣體分離

並列摘要

This study started from dicyclopentadiene (DCPD), one of by-products when producing ethylene by the distillation of petroleum hydrocarbons, to synthesize novel cyclopentyl cardo-structure containing diaime monomers and their corresponding cardo polyimides. A cardo-structure containing diol intermediate, CPDP, was prepared through alkylation of 4-cyclopentenyl phenol (CPP) possessing a single reaction site. CPP was synthesized from cyclopentadiene (CPD), through heat degradation of DCPD, and followed by alkylation and isomerization. This intermediate was obtained from alkylation or addition reactions. With the raw materials from commodity chemicals, this research obtained milder reaction conditions and shorter reaction time. The cardo-structure containing diamine monomer (C1) and the one with ortho-hydroxyl group (C2) or without (C1) were further synthesized from CPDP with 4-Fluoronitrobenzene or 5-Fluoro-2-nitrophenol and followed by hydrogenation. The corresponding cardo polyimides (CPIs) was prepared from C1 and C2 with commercial dianhydrides. Moreover, CPI-4, prepared from C2 and 6FDA will occur an imide-to-benzoxazole thermal rearrangement (TR) because of the present of ortho-positioned hydroxyl group on the carbonyl group of imide ring and accompanied by decarboxylation.
CPIs exhibited good thermal properties with glass transition temperature (Tg) of 244-313 ℃ and no weight loss below 450 ℃except for CPI-4. TGA showed that a decarboxylation (corresponding to TR) of CPI-4 was induced in the temperature range 315-360 ℃. In addition, comparing with conventional aromatic polyimide, CPIs exhibited higher solubility due to the inhibiting molecular packing by introducing cardo structure. This results were evidenced by the investigations of WAXD. In GPA, CPI-3, prepared from C1 and 6FDA, exhibited higher gas permeability than the commercially available polyimides with a CO2/CH4 selectivity of 46 that had more potential to be applied in CO2 capture

並列關鍵字

dicyclopentadiene；polyimide；gas separation

參考文獻

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