同位性聚2-乙烯基吡啶之合成和探討其誘導掌性效應及自組裝行為

Structurally well-define isotactic Poly(2-vinylpyridine)：Syntheses and use in the chiral dopant induced Circular Dichrorism and Self-Assembly studies

洪海峯(Hai-Fong Hong)

指導教授 ： 蔡敬誠

國立中正大學/工學院/化學工程學系/碩士(2014年)

摘要

具有立體規則性的高分子在物理性質上有許多特別之處，相同的高分子在不同立體規則性之下所表現出來的物理及化學性質皆有所差異。本研究針對同位性聚2-乙烯基吡啶(isotactic poly-2-vinylpyridine，iP2VP)作探討，因先前的研究中發現同位性聚2-乙烯基吡啶(iP2VP)在參雜酸性掌性誘導混摻物(chiral dopant) 使其自組裝形成類似生物體的螺旋性結構後進行圓極化雙色光譜儀(CD)之測定效果最佳。因此特別針對iP2VP以不同之格林納試劑反應，進而選擇較佳之觸媒進行合成，並將iP2VP高分子進行一系列末端官能化反應，合成雙嵌段共聚物(block-copolymer)已達研究目的，希望可以進一步達到開發具備新穎特殊物性材料之目的。
為達到合成雙嵌段共聚物之目的，希望合成末端帶有特殊官能基之iP2VP高分子，所以首先使用4-溴苯甲基溴與鎂粉合成出末端帶有雙鍵之格林納試劑，並與2VP單體合成帶有雙鍵之同位聚2-乙烯基吡啶(iP2VP- t-allyl)。
但由於新型格林那觸媒合成出之2VP高分子帶有部分對後續嵌段共聚物的不利因素，因此改由t-BuPhMgBr取代之，並利用末端活性點living的特性行一系列有機化學反應使iP2VP進行末端官能化，依序合成出末端帶有雙鍵(iP2VP-t-allyl)、氫氧基(iP2VP-t-hydroxyl)、溴酯基 (iP2VP-t-bromoester)等特殊官能基高分子起始劑(Macro-initiator)。
最後使用上述之Macro-initiator 與單體caprolactone行開環聚合(Ring Opening polymerization)與Styrene行ATRP聚合反應可分別成功的合成出iP2VP-b-PCL與iP2VP-b-aPS雙嵌段共聚高分子，另外再藉以GPC、NMR、SAX、TEM之儀器驗證結果確認此雙嵌段共聚高分子之成功合成。

關鍵字

掌性 ； 立體規則性 ； 自組裝

並列摘要

Stereoegular tactic Polymers have many unique physical and chemical properties and applications, and hence have drawn tremendous research attentions. In this report, stereoregualr isotactic poly-2-vinylpyridine (iP2VP) was synthesized and used to combine with various chiral dopants to examine if the combination of stereoregualr (tactic) polyolefins and chiral dopants can induced circular dichroism (ICD) driven by the formation of helical conformation along the iP2VP main chain.
In the syntheses of iP2VP, two kinds of Grignard reagents, including para-3-butenylphenylmagnesium bromide and 4-tertbutylphenylmagnesium bromide, were synthesized and used as initiators. Our results indicates that the polymerization of 2-vinylpyridine by using the 2-vinylpyridine as the initiator offers the production of iP2VP with exceptional high isotacticity control (mmmm > 90 %). We also demonstrated that the isospecific polymerization of 2-vinylpyridine initiated by 4-tertbutylphenylmagnesium bromide showed a living polymerization pathway. Accordingly, iP2VP-based block copolymers can be prepared through the living polymeriaztion,funtionalization,and then block copolymerization pathways.
The research focuses on two parts, first, syntheses and structural characterization of new Grignard reagent and second, preparations of iP2VP-based stereoregular diblock copolymers. The resulting iP2VP-based diblock copolymers can be used to combine with chiral dopant to examine the possibility of forming helical assembly via the molecular recognition processes。

並列關鍵字

Self- assembly ； Chiral ； Stereoregularity

參考文獻

[2] R. M. Ho, Y. W. Chiang, C. C. Tsai, C. C. Lin, B. T. Ko and B. H. Huang, J. Am. Chem. Soc., 126, 2704 2004

[4] M. N. Rosenbluth and A. W. Rosenbluth, J. Chen. Phys., 23, 356 1955

[5] N. Hadjichristidis and L. J. Fetters, Macromolecules, 13, 191 1980

[12] K. Matyjaszewski, S. Gaynor, J. S. Wang, Macromolecules 1995, 28, 2093-2095.

[15] A. M. de Oliveira, P. C. de Oliveira, A. M. dos Santos, M. H. A. Zanin, M. Ines R Brazilian Journal of Physics, vol. 39, no. 1A, April, 2009