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

Autor: Ya-Chin Huang, 黃雅琴
Rok vydání: 2018
Druh dokumentu: 學位論文 ; thesis
Popis: 106
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
Databáze: Networked Digital Library of Theses & Dissertations
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