Aluminoxane-based Activator Chemistry

塑料是一种用途广泛的材料，用于大量的产品。聚烯烃是由烯烃单体(含C=C双键的简单分子)聚合形成长链碳氢化合物(以C-C单键为骨架)制成的一类塑料。在催化剂的帮助下，它们在世界各地大量生产。催化剂加速化学反应而本身不受影响，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协助所需的转化，而这一活化步骤的关键工业方法是使用大量的高活性化合物，称为甲基铝氧烷(MAO)。过量使用量如此之高(1000-10,000当量)，以至于MAO在催化系统的成本中占了相当大的比例。大量使用可能是因为MAO的激活成分(S)只作为整体的一小部分存在，但MAO的复杂性使得它在超过25年的时间里一直拒绝明确的定性。 我们计划使用电喷雾电离质谱仪(ESI-MS)，这是一种最常应用于生物大分子研究的工具，来解决MAO表征问题。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者，我们已经做好了充分准备，以证明其在工业相关环境中的相关性。有前景的化合物将被综合定位，我们将利用我们的支持组织Nova Chemals的经验和资源来探索我们发现的新材料的活性。 我们的最终目标是了解足够多的铝氧烷化学，以大大减少催化剂活化过程中这种材料所需的过剩，大幅降低形成聚烯烃材料的这一步骤的成本：这种化学将变得更清洁、更安全、更便宜，由于每年制备大量的聚烯烃，这样的发现的意义很大。

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.