Iron and aluminum phosphido complexes for the sterocontrolled synthesis of biodegradable polymer brushes and stars

用于生物可降解聚合物刷和星形立体控制合成的铁和铝磷配合物

• 批准号: 356015-2008
• 负责人: Shaver, Michael
• 金额: $ 2.33万
• 依托单位: University of Prince Edward Island
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=459696
• 关键词: Iron; aluminum; phosphido; complexes; sterocontrolled

Green chemistry is a set of chemical ideals that drive many chemists towards sustainable and environmentally friendly operations. These concepts include: (i) atom economy, where ideally 100% of the atoms you put into a reaction vessel end up in the product, (ii) reduced toxicity, where toxic reagents are exchanged for bioassimilable alternatives, (iii) renewable feedstocks, replacing depleting petroleum-based products with sustainable resources, and (iv) catalysis, where specialized transformations can be performed without the wasteful use of stoichiometric reagents. In particular, the use of petroleum-based non-renewable resources in the production of plastics and polymers and the environmental impact of the associated waste necessitates research into alternatives. Poly(lactic acid), or PLA, is a commercially relevant, non-toxic and biodegradable thermoplastic which is readily produced through the ring-opening polymerization of a chemical called lactide. This lactide monomer is also renewable, as the lactate from which it is ultimately produced is derived from the fermentation of agricultural by-products. Research into PLA has placed it at the forefront of biodegradable polymer research, however applications remain limited to the clothing and packaging industries. Expanding the use of PLA requires chemists to improve and tune the properties of the polymer. Just as our left and right hands cannot be overlain, many molecules also have a characteristic handedness. By controlling how these hands, or stereoisomers, fit together in a polymer chain, we can improve polymer properties: a random arrangement gives a sticky glass, an alternating arrangement gives a white solid, while the desired stereocomplex form of PLA offers enhanced thermal properties. This project designs new catalysts for the stereocontrolled polymerization of lactide. These catalysts will be based on inexpensive metals including iron and vanadium supported by novel phosphorus ligands. Stereocontrol will also be incorporated into larger polymer architectures, including shapes resembling brushes and stars to produce new value-added products. Production of these new materials will expand the applications of environmentally friendly biodegradable polymers to the benefit of society.

绿色化学是一系列化学理想，推动许多化学家走向可持续和环保的运营。这些概念包括：（i）原子经济性，理想情况下，100%的原子放入反应容器中最终成为产品，（ii）降低毒性，将有毒试剂换成可生物同化的替代品，（iii）可再生原料，用可持续资源取代消耗的石油基产品，以及（iv）催化，可以进行专门的转化，而不会浪费化学计量试剂。特别是，在塑料和聚合物生产中使用石油基不可再生资源以及相关废物对环境的影响，需要研究替代品。聚（乳酸）或PLA是一种商业上相关的、无毒的和可生物降解的热塑性塑料，其容易通过称为丙交酯的化学物质的开环聚合来生产。这种丙交酯单体也是可再生的，因为最终产生丙交酯单体的乳酸盐来源于农业副产品的发酵。对PLA的研究使其处于可生物降解聚合物研究的最前沿，但应用仍仅限于服装和包装行业。扩大PLA的使用需要化学家改进和调整聚合物的性能。就像我们的左手和右手不能重叠一样，许多分子也有一种特有的手性。通过控制这些手或立体异构体如何在聚合物链中结合在一起，我们可以改善聚合物的性质：随机排列产生粘性玻璃，交替排列产生白色固体，而所需的PLA立体复合物形式提供增强的热性能。本项目设计了丙交酯立体可控聚合的新型催化剂。这些催化剂将基于廉价的金属，包括铁和钒，由新型磷配体支撑。立体控制也将被纳入更大的聚合物结构，包括类似刷子和星星的形状，以生产新的增值产品。这些新材料的生产将扩大环境友好型生物降解聚合物的应用，造福社会。