Aluminoxane-based Activator Chemistry

塑料是一种用途广泛的材料，用于各种各样的产品。聚烯烃是一类由烯烃单体（含有C=C双键的简单分子）聚合形成长链烃（具有C-C单键主链）制成的塑料。它们在催化剂的帮助下在世界范围内大量生产。催化剂加速化学反应而自身不受影响，并且在聚烯烃的制备中，使用含有过渡金属的催化剂。然而，催化剂需要活化才能够帮助所需的转化，并且该活化步骤的关键工业方法是使用大量过量的称为甲基铝氧烷（MAO）的高反应性化合物。使用的过量是如此之高（1000- 10，000当量），以至于MAO占催化体系成本的很大比例。过量使用可能是由于MAO的活化组分仅作为整体的一小部分存在，但MAO的复杂性使得其在超过25年的时间里一直拒绝明确表征。我们计划使用电喷雾离子化质谱（ESI-MS），一种最常用于生物大分子研究的工具，对微弧氧化表征的问题。我们的初步结果证明了我们方法的可行性，我们已经确定了MAO活性成分的可能候选物，并且我们已经准备好在工业相关环境中证明其相关性。我们将以合成为目标，利用我们的支持机构NOVA Chemicals的经验和资源，探索我们发现的新材料的活性。我们的目标是最终充分了解铝氧烷化学，以大大减少催化剂活化过程中所需的过量铝氧烷材料，从而大幅降低聚烯烃材料成型步骤的成本：这种化学方法将变得更清洁、更安全和更便宜，并且由于每年制备的大量聚烯烃，这种发现的重要性很高。

Plastics are versatile materials used in an enormous array of products. Polyolefins are one class of plastics made from polymerizing olefin monomers (simple molecules containing a C=C double bond) to form a long chain hydrocarbon (with a backbone of C-C single bonds). They are made in huge quantity worldwide with the help of catalysts. Catalysts speed chemical reactions without themselves being affected, and in the preparation of polyolefins, catalysts containing transition metals are used. However, the catalyst requires activation before it is able to assist the desired transformation, and the key industrial approach to this activation step is to use a large excess of a highly reactive compound called methylaluminoxane (MAO). The excess used is so high (1000-10,000 equivalents) that MAO represents a significant proportion of the cost of the catalytic system. The excess used is probably due to the fact that the activating component(s) of MAO are present only as a small fraction of the whole, but the complexity of MAO is such that it has resisted unambiguous characterization for over 25 years. We plan to use electrospray ionization mass spectrometry (ESI-MS), a tool most often applied to the study of biological macromolecules, to the problem of MAO characterization. Our preliminary results demonstrate the feasibility of our approach, we have identified a likely candidate for the active ingredient of MAO, and we are well set to demonstrate its relevance in an industrially relevant setting. Promising compounds will be targeted synthetically, and we will use the experience and resources of our supporting organization, NOVA Chemicals, to explore the activity of the new materials that we discover.Our goal is ultimately learn enough about aluminoxane chemistry to greatly reduce the required excess of this material in catalyst activation, substantially reducing the cost of this step in forming polyolefin materials: this chemistry will become cleaner, safer and less expensive, and the significance of such a discovery is high due to the vast quantities of polyolefins prepared every year.