Metallocene觸媒誘導之選擇性鏈轉移反應及其應用於合成立體規則性嵌段共聚合物

Preparations of Stereoregular Block Copolymers Via Metallocene-Catalyst-Mediated Selective Chain Transfer Reactions

蔡敬誠(Jing-Cherng Tsai) ； 王柏勳(Bo-Xun Wang)

《化學》 73卷2期 (2015/06) Pp. 95-103

https://doi.org/10.6623/chem.2015010

摘要

立體規則性嵌段共聚物，除了具備立體規則性之嵌段化學結構之外，不同高分子嵌段之間必須以化學鍵結相接連。此兩項化學結構特徵造成立體規則性嵌段共聚物合成之問題。理論上乙烯基類單體 (α-olefinmonomers) 聚合之立體規則性可藉由Zieglar-Natta 或Metallocene 觸媒來加以控制，但Zieglar-Natta 或Metallocene 等配位聚合之反應機理為非活性聚合 (Non-living polymerization)，因此無法提供直接銜接不同高分子嵌段之間化學鍵結的方法；相對的傳統之活性聚合 (如：活性陰離子聚合，活性自由基聚合) 雖提供不同高分子嵌段之間形成化學鍵結以生成嵌段共聚物之方法，但卻無法提供乙烯基類單體聚合之立體規則性控制。本報告則提供過去幾年來，我們針對立體立體規則性嵌段共聚物合成問題之相關研究。

關鍵字

鏈轉移反應 ； 末端官能化 ； 立體規則性嵌段共聚物

並列摘要

Structurally well-defined polyolefin-based diblock copolymers, which can be used in the self-assembly studies for displaying consistent nanomorphologies, are mostly prepared by living polymerization routes (e.g., living anionic, controlled-living free radical, controlled-living ring opening polymerizations) as these synthetic routes offer the direct linking methods for connecting different blocks and provide perfect controls in molecular chain length and molecular weight distribution. Unfortunately, these living synthetic routes typically fail to facilitate stereoregularity control during α-olefin polymerizations, and hence preparations of stereoregular block copolymers remain to be a synthetic challenge. This report summarizes our recent efforts in the utilization of stereoregular metallocene catalysts to mediate the simultaneous stereoregularity and endfunctionalization controls during polymerization of α-olefins, and this leads to the production of end-functionalized stereoregular polymers, which can be used as key precursors (macroinitiators) for the synthesis of stereoregular block copolymer through post-polymerization reactions.

並列關鍵字

Metallocene ； Stereoregular block copolymers ； Stereoregularity control ； Endfunctionalization ； Macroinitiator