アクリルアミドからの極性モノマー挿入ポリメリゼーションに関する機械学的洞察
Tobias Friedberger1, Philipp Wucher, Stefan Mecking
1Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
Journal of the American Chemical Society
|January 5, 2012
まとめ
この研究では,極性添加物は,N-イソプロピルアクリルアミド (NIPAM) と関連するモノマーをエチレンでパラジアム触媒による共ポリメリゼーションを有意に阻害することを明らかにしています. 抑制の程度は,添加物の種類によって異なります.
科学分野:
- オーガノメタリック化学
- ポリマー化学 ポリマー化学
- カタリシス カタリシス カタリシス
背景:
- パラジウム複合体は,オレフィンポリメリゼーションとコポリメリゼーションの効果的な触媒である.
- アクリルアミドモノマーには,極性アミド群があるため,ポリメリゼーションにおいてユニークな課題があります.
- モノマー挿入機構と触媒阻害の理解は,ポリマーの性質を制御するために重要です.
研究 の 目的:
- N-イソプロピルアクリラミド (NIPAM),N,N-ジメチルアクリラミド (DMAA),および2-アセタミドエチルアクリラート (AcAMEA) のエチレンとの共ポリメリゼーションをパラジウム触媒を使用して調査する.
- ポリメリゼーションプロセスを阻害する極性添加物の役割を明らかにする.
- パラジアム-メチル結合に異なるアクリラミドモノメアの挿入地域選択性と運動性を決定する.
主な方法:
- 特定のパラジウム触媒前駆体, [(P^O) PdMe(DMSO) ] を使った共ポリマー化反応.
- 阻害効果を定量化するために,様々な非ポリメリ化性極性添加物を用いた阻害研究.
- モノマー挿入のための擬似第一順位の速度定数を決定することによって,運動分析.
- 電気スプレー・イオン化質量スペクトロメトリー (ESI-MS) と単結晶X線 difraktionを用いた反応製品の構造的特徴化.
主要な成果:
- 自由アミド群のパラジアム中心への可逆的なカッパ-O-調整は,ポリメリゼーションを大幅に遅らせます.
- ポリメリゼーションの阻害は,添加物の極性によって増加し,DMSOが最も顕著な遅延を引き起こします.
- モノメア挿入率は,DMAA < AcAMEA < NIPAM < メチルアクリラート の順に進みます.
- NIPAMの連続挿入製品とDMAAの2,1および1,2挿入製品の両方を特定し,構造的に特徴づけました.
結論:
- アクリルアミドとエチレンのパラジウム触媒共ポリメリゼーションは,極性機能群に敏感であり,触媒阻害につながります.
- アミド群のパラジウム中心への協調は,ポリメリゼーション運動を調節する上で重要な役割を果たします.
- これらの相互作用を理解することで,ポリメリゼーションプロセスをよりよく制御し,新しいポリマーアーキテクチャの設計が可能になります.
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