溶融中のポリオルフェンのロジウム触媒による地域特有の機能化
Yuichiro Kondo1, Domingo García-Cuadrado, John F Hartwig
1Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, USA.
Journal of the American Chemical Society
|February 14, 2002
まとめ
ロジウム触媒によるボリレーションは,ポリマー側鎖にボリル基を加えることでポリオレフィンを変更する. その後の酸化は,ヒドロキシル基を導入し,ガラスの移行温度のようなポリマーの性質を高めます.
科学分野:
- ポリマー化学のポリマー化学について
- 有機金属化学 有機金属化学
- マテリアルサイエンス 材料科学
背景:
- ポリオレフィンは多用途のポリマーですが,機能化は困難です.
- ポリマーサイドチェーンの選択的改変は,材料の特性を調整するために不可欠です.
- アルカンボリレーションは,ポリマー機能化のための潜在的な経路を提供します.
研究 の 目的:
- ポリエチレチレン (PEE) のロジウム触媒末端選択性ボリレーションを調査する.
- PEEをボリル基で機能化し,その後それらをヒドロキシル基に変換する.
- この改変が分子量やガラスの移行温度などのポリマー特性への影響を評価する.
主な方法:
- bis-pinacoldiboronと[Cp*RhCl2]2触媒を用いたPEEのロジウム触媒によるボリレーション.
- ボリル化PEEの酸化により,ヒドロキシル基を導入する.
- NMRスペクトロスコーピー,MALDI-MS,GPC,Tg測定を用いた特徴づけ
主要な成果:
- PEEのターミナル選択性ボリレーションが成功しました.
- ボリル化ポリマーの水酸化により,末端のヒドロキシル基を持つポリマーが得られました.
- ポリマーの分子量とポリ分散性はほとんど変わらなかった.
- ガラス化温度 (Tg) が最大50°C上昇することが観察されました.
結論:
- 均質な,触媒的,選択的なアルカンの機能化は,ポリオレフィンを変更するのに有効です.
- 末端ボリル化に続く酸化は,ヒドロキシル基をポリオレフィンに導入する有効な方法である.
- この改変戦略により,ポリマーの熱特性が大幅に改善できます.
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