メタルロセンの触媒からのポリプロピレンにおける構造-特性相関:ステレオデフェクト,レギオレギュラー,イソタキシカルポリプロピレン
Claudio De Rosa1, Finizia Auriemma, Annunziata Di Capua
1Dipartimento di Chimica, Università di Napoli Federico II, Complesso Monte S. Angelo, Via Cintia, 80126 Naples, Italy.
Journal of the American Chemical Society
|December 23, 2004
まとめ
新しいメタロセノ触媒は,調節性特性を有するカスタマイズされたポリプロピレンを生み出します. イソタクティックポリプロピレンの地域エラー (rr欠陥) を制御することで,硬いプラスチックから柔軟な熱プラスチック,強固なエラストーマーまで,機械的動作の正確な調整が可能になります.
科学分野:
- ポリマー化学のポリマー化学について
- マテリアルサイエンス 材料科学
- カタリシス カタリシス カタリシス
背景:
- メタロセンの触媒は,ポリマーの微細構造を正確に制御することを可能にします.
- アイソタクティックポリプロピレンの特性には,ステレオレギュラー性や欠陥が影響する.
- レジオエラー (rr 欠陥) は,ポリプロピレンの多形性行動と機械特性に影響を与えます.
研究 の 目的:
- 新しいC(1) -対称性インデニル-アンサ-ディチエノcyclopentadienylベースのジルコノセンを使用して,異なるレベルのステレオレギュラリティを持つイソタクティックポリプロピレンを合成する.
- ポリプロピレン (polypropylene) のポリモルフィック行動と機械的特性に対する地域エラー (rr欠陥) の影響を調査する.
- 欠陥の濃度,多形形状,および材料の特性との関係を確立するために.
主な方法:
- MAO活性化C(1) -対称性インデニル-アンサ-ディチエノサイクロペンタディエニル基ジルコノセンの合成.
- プロピレンのポリメリゼーションにより,制御された分子量とステレオレギュラリティを持つ同質ポリプロピレンを生成します.
- ポリモルフィック行動 (ガンマと無秩序の形態の結晶化) と,rrrの欠陥濃度の関数としての機械的性質の分析.
主要な成果:
- rr欠陥の存在は,ガンマ形態の結晶化と中間の無秩序な修正を引き起こす.
- ガンマ形態の量とイソタクシーシーシーンの平均長さの間の線形関係が見つかりました.
- 3〜4%のrr欠陥を有するポリプロピレン試料は,高融点 (130〜160°C) を示し,硬質プラスチック材料として作用する.
- 4~6%のrr欠陥を有する試料は,より低い融点 (115~120°C) を示し,柔軟な熱塑性材料のように振る舞う.
- 7~11%のrr欠陥を有する試料は80~110°Cの融点を持ち,高強度熱塑性弾性体として機能する.
結論:
- メタルロセネ触媒の量身設計により,ポリプロピレン鎖の微細構造を微調整することができます.
- rr欠陥の制御は,性質のスペクトルを持つポリプロピレンの生産を可能にし,硬いプラスチックと弾性体を橋渡しします.
- このアプローチは,特定の用途のために望ましい中間特性を持つ新しいポリプロピレン材料の開発を容易にする.
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