A-B-A三嵌段聚(9,9-雙辛基茀)共聚合體 之合成與性質研究

Studies on the synthesis and properties of Poly(9,9-dioctylfluorene) A-B-A triblock copolymer

林佳生(Chia-Sheng Lin)

指導教授 ： 廖建勛

元智大學/工程學院/化學工程與材料科學學系/碩士(2006年)

摘要

本研究以Yamamoto偶合2,7-二溴-9,9-二辛烷基茀單體並加入烷氧胺衍生物為末端封端劑合成聚(9,9-雙辛基茀) (PFO)起始劑，進行聚(9,9-雙辛基茀)末端之苯乙烯活性自由基聚合，所製備之共軛棒桿-線團結構形態之A-B-A三嵌段共聚體，以NMR、FT-IR光譜儀作結構鑑定，GPC測定分子量n，TGA、DSC作熱性質分析，UV-Vis、PL光譜分析光吸收與放射、Raman光譜儀分析不同形態異構物，並經由SEM、AFM的形態學分析，探討嵌段共聚合體的表面形態。隨著PS嵌段比例增大，嵌段共聚體的熱穩定性下降，而分子鏈內規則性增加。PFO均聚體及其嵌段共聚體之介穩態(β相)可經由物理化學處理獲得，其熱消散溫度在82~90℃、光吸收波長範圍在426~432nm、光放射波長範圍在436nm、460~463nm、494~496nm。而Raman散射的波數位移在 1307cm-1，當溫度改變時，Raman散射波數增加，證明β相轉變為α或γ相的形態異構物。SEM與AFM的表面形態分析，觀察到自組裝超分子之結構中結構的微相分離形態。

關鍵字

活性自由基聚合 ； 三嵌段共聚體 ； 超分子結構中結構

並列摘要

Poly(9,9-dioctylfluorene) (PFO) macroinitiator was prepared by Yamamoto coupling of 2,7-dibromo-9,9-dioctylfluorene with end-capped alkoxyamine derivative. The polystyrene segments grew from chain ends of PFO to form conjugated rod-coil triblock (A-B-A) copolymers by living free radical polymerization. The NMR and FT-IR spectra were used for the structure characterization and the molecular weight was measured by GPC analysis. In addition, the thermal analysis by TGA and DSC, optical properties measurement by UV-vis and PL spectra, different conformational isomer identified by Raman spectra and surface morphology analysis by SEM and AFM were performed for both PFO homopolymer and triblock copolymers. The thermal stability of block copolymers decreased as increasing PS segment length. However, the intrachain ordered structure was enhanced for the increase of PS block length. The metastable state (β phase) of PFO homopolymer or triblock copolymers was formed by physical chemistry method. The characteristic electronic absorption at 426~432nm was assigned for the β phase of PFO segment, which emitted at 436nm, 460~463nm, and 494~496nm. The β phase dissipated at the temperature range between 82~90 ?aC. The β phase transfered to α phase or γ phase in different temperature range led to an increase of Raman shift from 1307 cm-1. The microphase-separated morphology was observed as supramolecular structure-within-structure by SEM and AFM.

並列關鍵字

living free radical polymerization ； triblock copolymer ； supramolecular structure-within-structure

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