双语化学辞典Chem Lexicon
化合物 · 高分子化学 · 配位聚合 Polymer chemistry · Coordination polymerisation

齐格勒-纳塔催化剂Ziegler–Natta catalyst

拼音Pinyin qí gé lè nà tǎ cuī huà jì　别名Also Z-N 催化剂； Ziegler catalyst

定义Definition

齐格勒-纳塔催化剂是由过渡金属化合物（如 TiCl₄、TiCl₃）与烷基铝助催化剂（如 Al(C₂H₅)₃）组成的催化体系，能在低压下使乙烯聚合成高密度聚乙烯，并使丙烯等 α-烯烃进行立构规整（等规）聚合。

A Ziegler–Natta catalyst combines a transition-metal compound (e.g. TiCl₄ or TiCl₃) with an alkylaluminium co-catalyst (e.g. Al(C₂H₅)₃). It polymerises ethylene at low pressure to high-density polyethylene and polymerises propylene and other α-olefins stereoregularly (isotactically).

机理Mechanism

烷基铝使钛中心烷基化并形成空配位点。按科西-阿尔曼机理，烯烃先与 Ti 配位，再插入 Ti–C 键（四元环过渡态），空位迁移后重复插入，链不断增长。催化剂表面的手性环境使每次插入都以相同的面进行，从而得到等规聚丙烯。

The alkylaluminium alkylates titanium and creates a vacant site. In the Cossee–Arlman mechanism the olefin coordinates to Ti and inserts into the Ti–C bond via a four-centre transition state; the vacancy migrates and insertion repeats. The chiral environment of the surface site makes each insertion use the same face, giving isotactic polypropylene.

由来Origin

1953 年德国的卡尔·齐格勒发现 TiCl₄/烷基铝能在常压下聚合乙烯；1954 年意大利的居利奥·纳塔用它制得等规聚丙烯并阐明立构规整性。二人共获 1963 年诺贝尔化学奖。

In 1953 Karl Ziegler in Germany found that TiCl₄/alkylaluminium polymerises ethylene at atmospheric pressure; in 1954 Giulio Natta in Italy made isotactic polypropylene and explained its stereoregularity. They shared the 1963 Nobel Prize in Chemistry.

发展Development

MgCl₂ 负载的高效催化剂（1960–70 年代）加入内、外给电子体，活性和等规度大幅提高，可省去脱灰步骤；后来的茂金属与后过渡金属单中心催化剂可精确控制分子量分布和立构。聚乙烯、聚丙烯是产量最大的塑料。

MgCl₂-supported high-activity catalysts with internal and external donors (1960s–70s) raised activity and isotacticity enough to skip de-ashing; later metallocene and late-metal single-site catalysts control molar-mass distribution and tacticity precisely. Polyethylene and polypropylene are the highest-volume plastics.

反应Reactions

n CH2=CHR TiCl4/AlEt3⟶ –[CH2–CHR]ₙ–等规n CH2=CHR TiCl4/AlEt3⟶ –[CH2–CHR]ₙ–

烃溶剂或气相，50–100 °C，低压

Hydrocarbon slurry or gas phase, 50–100 °C, low pressure

  1. 烷基铝使钛烷基化、生成活性中心和空位。

    Alkylaluminium alkylates Ti, creating an active site with a vacancy.

  2. 烯烃配位到空位。

    The olefin coordinates at the vacancy.

  3. 烯烃插入 Ti–C 键，链增长。

    The olefin inserts into Ti–C, extending the chain.

  4. β-H 消除或向 H₂、烷基铝链转移终止链。

    β-H elimination or chain transfer to H₂ or aluminium ends the chain.

n CH2=CH2 ⟶ HDPE高密度聚乙烯n CH2=CH2 ⟶ HDPE(Polyethylene)

低压法聚乙烯。

Low-pressure polyethylene.

年表Timeline

  • 1953

    齐格勒发现低压乙烯聚合

    Ziegler discovers low-pressure ethylene polymerisation

  • 1954

    纳塔合成等规聚丙烯

    Natta prepares isotactic polypropylene

  • 1963

    两人获诺贝尔化学奖

    They share the Nobel Prize in Chemistry

  • 1980

    卡明斯基发现茂金属/MAO 高效体系

    Kaminsky finds highly active metallocene/MAO catalysts