硬軟嵌段共聚高分子之合成與製備蜂窩狀多孔性薄膜之探討

Abstract

硬軟嵌段共聚高分子之合成與製備蜂窩狀多孔性薄膜之探討 學生：董寶翔 指導教授：張豐志教授 國立交通大學應用化學研究所

中文摘要

長久一來，在製備高規則多孔性的高分子薄膜方面對各方學者而言，一直是很大的挑戰，本研究將利用硬段-軟段嵌段共聚高分子在具有濕氣的環境中製備出高規則、蜂窩狀多孔性高分子薄膜。 本研究首先分別利用原子轉移自由基聚合反應(atom transfer radical polymerization , ATRP)與縮合反應合成poly(phenylquinoline)- block - poly(methyl methacrylate) (PPQ -b-PMMA) 硬-軟鏈段共聚高分子；在實驗中首先合出起始劑N-(4-acetylphenyl)-2-Bromo-2- methyl propanamide後再以原子轉移自由基聚合以N,N,N,□,N’□,N’□- Pentamethyl diethylenetriamine (PMDETA)為配位基和亞銅鹽類形成錯合物催化反應進行軟鏈段的聚合，最終再以縮合反應完成此嵌段共聚高分子。並經由氫核磁共振光譜(1H-NMR)、傅立葉轉換紅外線光譜(FTIR)、微分掃描熱卡計(DSC)，熱重分析儀(TGA)分析此硬軟鏈段共聚高分子的性質。由DSC測得本實驗合出具有高玻璃轉移溫度(Tg)的PMMA，以FTIR分析軟鏈段PMMA，其波數在1730 cm-1則為PMMA軟鏈段的carbonyl group的吸收峰，而在1060與1271cm-1處皆具有syndiotactic configuration的特殊吸收峰，故得知本方法合出的軟鏈段PMMA較趨向於syndiotactic configuration比例的形態，另經縮合反應將硬鏈段PPQ接上後，也可以在FTIR光譜中觀察到quinoline ring在1548cm-1、1589 cm-1、1342 cm-1與1021 cm-1的特殊吸收峰，此共聚高分子PPQ-PMMA以TGA分析得知由於硬段PPQ的影響而使得PMMA的熱裂解溫度(Td)上升至350℃。 而後將合成出的硬段-軟段嵌段共聚高分子溶於適當的溶劑中，在具有水氣及風速一定的環境中製備出高規則蜂窩狀、六角柱的多孔性薄膜，並以偏光顯微鏡(OM)及掃描式電子顯微鏡(SEM)觀察此高分子薄膜。此外，探討共聚高分子在不同濃度與成膜條件下的型態學與孔洞大小、壁厚的趨勢，並成功的控制此高規則多孔性高分子薄膜的孔洞大小。

Synthesis of Rod-Coil Dibolck Copolymers Using ATRP and their Honeycomb Morphology Formed by the “Breath Figures” Method

Student：Pao-Hsiang Tung Advisor：Dr. Feng-Chih Chang

Institute of Applied Chemistry National Chiao Tung University

Abstract

A great challenge in the preparation of porous polymer membrane for technological applications is to control both the size distribution and the relative positions of the pores. We have found an easy way to prepare polymer films with monodisperse pore size. The films are produced by evaporating solutions of rod-coil copolymers in high vapor solvent under a flow of moist gas. This thesis was used atom transfer radical polymerization (ATRP) and condensation polymerization to synthesize poly (phenylquinoline)- block – poly (methyl methacrylate methacrylate) (PPQ-b-PMMA). Frist, the flexible segment PMMA was synthesized via ATRP. Then, the ketone metylene groups in PMMA serve as bridge to connect phenylquinoline (rigid segment) polymerization. The rod-coil dibolck copolymers were investigated by proton nuclear magnetic resonance spectrometry (1H-NMR), Fourier transfer infrared spectrophotometer (FTIR), differential scanning calorimeter (DSC), thermogravimeter analysis (TGA). The decomposition temperature of the rod-coil diblock copolymer is higher than the PMMA homopolymer. The presence of the PPQ block tends to retard the early decomposition of the PMMA chain.And the special functional group terminated PMMA has more syndiotactic ratio which was analyzed by 1H-NMR or FTIR spectrum. Finally, a regularly porous honeycomb structured film can be prepared from the dichloromethane solution of the rod-coil diblock copolymers under moisture air flow.The water droplets self-organize into a regular array and serve as a highly regular template for the precipitating polymer. We argue that the most important element in the formation of order structure may be determined on the polymer to precipitate at solution / water interface. The diameter of the spherical pores can be controlled ranging from 0.8 μm to 3 μm by the rod-coil copolymers relative molecular weight as well as by the casting conditions.