Advisor ： Professor Guey-Sheng Liou Reporter ： Huan-Shen Liu 2015 / 01 / 09Special Topics on Polymers Synthesis Report Hirao, A.; Uematsu, M.; Kurokawa, R.; Ishizone,T. Macromolecules 2011, 44,

Outline  Introduction  Result and Discussion  Conclusions 2

3 Introduction

Definitions-What is Graft Polymers? 4  Graft polymers are segmented copolymers with a linear backbone of one composite and randomly distributed branches of another composite. backbone (A) graft chain (B)

Three Parameters 5  The structure of a graft (co)polymer can be defined by the following three parameters: Molecular weight of the backbone chain Molecular weight of the graft chain Distance (or molecular weight) between the graft chains Paraskeva, S.; Hadjichristidis, N. J. Polym. Sci., Part A: Polym. Chem. 2000, 38,931

Three General Methods 6  A variety of graft (co)polymers have been usually synthesized by three general methods: (1)Grafting onto (2)Grafting through (3)Grafting from J. H. Hu, X.Y. Huang, Chem. Soc. Rev., 2011,40,

Synthesis of Exact Graft Copolymer 7 Paraskeva, S.; Hadjichristidis, N. J. Polym. Sci., Part A: Polym. Chem. 2000, 38,931 第一個 PILi 接上去後所帶的 anionic 會穩 定整體結構，造成另一個雙鍵的反應性 下降

Synthesis of Exact Graft PSs Having Up to Five Graft Chains 8 Hirao, A.; Watanabe, T.; Kurokawa, R. Macromolecules 2009, 42, 3973 The addition reaction step,which requires an exact 1:1 stoichiometry between the reagents, could be avoided in this methodology. SN2SN2

Motivation 9  Although the developed methodology is thus effective for the synthesis of exact graft (co)polymers, the synthesis requires laborious multistep reactions. Five PS graft chains 10 linking reaction steps Process waste Improve the synthesis of exact graft (co)polymers, with which a diverse range of exact (co)polymers including a double-tailed exact graft PS are synthesized by fewer numbers of reaction steps.

10 Result and discussion Preparation of In-Chain-(DPE) 6 -Functionalized (PS) 7 Used as a Backbone Polymer ‚Synthesis of Exact Comb PS and Exact Graft Copolymers ƒSynthesis of Double-Tailed Exact Graft PS

Preparation of In-Chain-(DPE) 6 -Functionalized (PS) 7 Used as a Backbone Polymer 11 Figure 1. 1 H NMR spectra of in-chain-DPE-functionalized PS α-terminal-functionalized with (a) 3-(tert- butyldimethylsilyloxy)propyl group, (b) 3-hydroxypropyl group, and (c) 3-bromopropyl group. Method1

12 Figure 2. Preparation of in-chain-(DPE)6- functionalized (PS)7 before (a) and after SEC fractionation (b). Preparation of In-Chain-(DPE) 6 -Functionalized (PS) 7 Used as a Backbone Polymer Method2 Li–Br exchange reaction

13 Preparation of In-Chain-(DPE) 6 -Functionalized (PS) 7 Used as a Backbone Polymer  In this synthesis, the number of reaction steps has been greatly reduced by employing the coupling reaction at the final stage. Method1 Method2 at least six coupling reactionsthree coupling reactions

Synthesis of Exact Comb PS and Exact Graft Copolymers 14 Synthesis of Exact Graft Comb PS Figure 3. SEC profiles of the reaction mixture (a) and exact graft comb PS having six PS graft chains obtained by fractional precipitation (b). Deactivated PSLi 2.2-fold excess

15 PILi was much less reactive than PSLi toward the DPE function in the PS chain.(same method as PSLi) Synthesis of Exact Comb PS and Exact Graft Copolymers Synthesis of Exact Graft Comb PI Improve PILi was end-capped with a few styrene units and then in situreacted with the backbone PS in order to complete the addition reaction. 在單體 isoprene 和 styrene 的活性是差不 多的，所以就活性來說， PILi 和 PSLi 應 該是差不多，可能原因就是對 DPE function 的活性不同

16 Synthesis of Exact Comb PS and Exact Graft Copolymers Synthesis of Exact Graft Comb PMMA The chain-end enolate anion of living PMMA cannot react with the DPE reaction site at all under normal conditions. Improve An α-phenyl acrylate (PA) function seems to be appropriate because of the quantitative linking reaction of the PA function with living PMMA. replace the DPE function by a more reactive reaction site

17 Synthesis of Exact Comb PS and Exact Graft Copolymers Synthesis of Exact Graft Comb PMMA Figure 4. 1 H NMR spectra of PS in-chain- multifunctionalized with (a) 3-tert- butyldimethylsilyloxy group, (b) hydroxyl group, and (c) α-phenyl acrylate group. 在 PMMA 接上去後所產生的立體障礙以及拉電子的穩定性將造成其無 法攻打另一個 PA 產生交聯 MMA 的單體活性較 styrene 大，所以 PMMA 的反應性較 PS 的反應性小

18 Synthesis of Exact Comb PS and Exact Graft Copolymers

Synthesis of Double-Tailed Exact Graft PS 19 PS-D6 PS-(PS) 6 PS-(PS 2 ) 6 Figure 5. SEC profiles of in-chain-(DPE) 6 - functionalized (PS) 7 (a), exact graft comb PS (b), and double-tailed exact graft PS (c).

20  Successfully synthesized a diverse range of new exact graft (co)polymers (PS backbone chain) having six PS, six PI, and six PMMA graft chains and double-tailed exact graft PS. Conclusion

21  The use of the coupling reaction enables the number of reaction steps to be significantly reduced.  Only the same chains in molecular weight and chemical structure can be introduced to the backbone polymer in the present methodology. The relationship of possible distance between branching points along the main chain and length of graft chains Next target Conclusion

Thank you for your attention. 22

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Mitsunobu reaction 24