含對位性聚苯乙烯衍生物之立體規則性雙嵌段共聚高分子：合成方法與奈米結構自我組裝研究

Stereoregular Diblock Copolymers of Syndiotactic Polystyrene Derivatives:Syntheses and Self-Assembled Nanostructures

黃雅凰(Ya-Huang Huang)

指導教授 ： 蔡敬誠

國立中正大學/工學院/化學工程學系/碩士(2012年)

摘要

本研究中將苯乙烯對位位置帶有Halides官能基的單體(4-Bromostyrene，4-BrS)，使用鎳金屬觸媒系統，誘導4-溴苯乙烯(4-Bromostyrene，4-BrS)單體與異丁基格氏試劑 (Isobutylmagnesium bromide)在鎳金屬觸媒催化下進行Kumada交叉耦聯反應 (Kumada cross-coupling reaction)，合成出新型對位位置具備立體障礙大的苯乙烯衍生物單體((4-isobutyl)styrene， (4-iBu)S)。
所合成之單體(4-iBu)S可使用金屬茂觸媒系統Cp*Ti(OMe)3/MAO，進行對位性選擇聚合反應以合成對位異丁基苯乙烯聚合物(Syndiotactic poly(4-isobutyl)styrene，sP(4-iBu)S)，藉由加入二甲基苯基乙烯基矽烷(dimethylphenylvinylsilane)作為鏈轉移劑則可生成末端具備二甲基苯基乙烯機矽烷之sP(4-iBu)S聚合物，經由去矽基、末端雙鍵氫硼化-氧化反應可有效得到末端具有氫氧 基的對位性聚對異丁基苯乙烯(hydroxyl-capped sP(4-iBu)S，sP(4-iBu)S-OH)。
本研究中還利用AlEt3作為co-initiator將sP(4-iBu)S-OH末端轉換成sP(4-iBu)S-OAlEt2之macroinitiator以進行環酯類單L-lactide的開環聚合反應，以合成出sP(4-iBu)S-b-PLLA之嵌段共聚高分子。最後我們可有效控制具有立體規則性的嵌段共聚高分子的比例並確定其結構，並藉由核磁共振儀(NMR)、小角度X光散射儀(small angle X-ray scattering)及穿透式電子顯微鏡(TEM)的分析下，我們可以確定嵌段高分子的結構及觀察其微觀相分離行為。

並列摘要

In this study, the original styrene structure can also be transfered to the isobutyl compounds by coupling 4-bromostyrene with isobutyl- magnesium bromide via the Nickel-catalyst-mediated Kumada coupling reaction. After that, 4-isobutylstyrene can be used as the monomers to undergo the syndiospecific polymerization.
The hydroxyl-capped sP(4-iBu)S was prepared from the hydro- boration of ethenyl-capped sP(4-iBu)S. The ethenyl-capped sP(4-iBu)S was generated by the desilylation of dimethylphenylvinylsilane-capped sP(4-iBu)S prepared via a unique vinylsilane-inducing selective chain transfer reaction during the syndiospecific polymerization of 4-isobutylstyrene conducted in the presence of dimethylphenyl- vinylsilane using Cp*Ti(OMe)3/MAO as catalyst.
We also demonstrated that the hydroxyl end-group of the sP(4-iBu)S-OH can be used to undergo living ring opening polymerization of D,L-lactide; thus, novel stereoregular diblock copolymers, including sP(4-iBu)S-b-PLLA, can be successfully prepared with high yield. Our studies clearly demonstrated that using the sP(4-iBu)S-OH as the macroinitiator for conducting living postpolymerization can lead to the successful preparations of novel stereoregular diblock copolymers, which do not require the tedious fractionation processes for removing homopolymers.
The stereoregular diblock copolymers possess precise chemical architectures (defining chemical structures with narrow ranges of molecular weight distribution) and can be self-organize into consistent nanostructures which can be proved through by small angle X-ray scattering studies.

並列關鍵字

Stereoregular Diblock Copolymers ； Self-Assembled

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