Membrane Recovery of Homogeneous Catalysts (TSE 99-D)

建议编号：CTS-9985552建议类型：响应NSF 99-108，NSF/EPA技术促进可持续环境规划主要研究人员：Mary Rezac和Haskell Beckham隶属：佐治亚理工学院膜回收均相催化剂均相催化剂因其反应速度快和选择性高而被用于化工生产。然而，回收和再循环这些催化剂是困难的，并产生大量浪费(1996年约为400万吨)。传统的技术不能很好地适应这种分离。这项研究项目考察了由交联二乙炔功能化聚合物开发的化学稳定的膜从水或非水反应混合物中选择性地回收均相催化剂的能力。如果成功，这项技术可以极大地扩大高选择性但往往昂贵的均相催化剂的使用，并极大地减少传统多相催化系统形成的不良副产物的体积。本研究的假设是，可以通过有机聚合物膜实现有机产品与金属配体催化剂的分离，有机聚合物膜基于两种化合物扩散速度的差异提供选择性。可以通过控制高分子链的分子运动来实现基于迁移率的选择性的定制。可以使用聚合物基质的选择性交联来获得这种控制。将对通过二乙炔官能团进行局部化学交联的聚合物进行研究，以探索该装置在不显著降低所需渗透剂的传输速率的情况下防止聚合物膨胀和同时丧失选择性的能力。样品的交联密度将被系统地改变，以评估所提出的假设。将测量每种渗透剂的溶解度和扩散系数。对膜回收均相催化剂的性能和回收催化剂的后续活性进行了评价。

AbstractProposal number: CTS-9985552Proposal type: Response to NSF 99-108, NSF/EPA Technology for a Sustainable Environment ProgramPrincipal investigators: Mary Rezac and Haskell BeckhamAffiliation: Georgia Institute of Technology Membrane Recovery of Homogeneous CatalystsHomogeneous catalysts are employed for chemical production because of their high reaction rates and selectivity. However, recovery and recycle of these catalysts is difficult and produces significant waste (approximately 4 million tons in 1996). Conventional techniques are not well suited to this separation. This research program examines the ability of chemically stable membranes developed from crosslinked diacetylene-functionalized polymers to selectively recover homogeneous catalysts from either aqueous or non-aqueous reaction mixtures. If successful, this technology could greatly expand the use of highly selective but often expensive homogeneous catalysts and dramatically reduce the volume of undesired by-products formed via conventional heterogeneous catalysis systems.The hypothesis of this study is that the separation of an organic product from a metal-ligand catalyst can be achieved with an organic polymer membrane that provides selectivity based on differences in the diffusion rates of the two compounds. Tailoring of mobility-based selectivity can be realized through control of the molecular motion of the polymer chains. Selective crosslinking of the polymer matrix can be used to gain this control. Polymers topochemically crosslinked via a diacetylene functionality will be investigated to probe the ability of this unit to prevent polymer swelling and the concurrent loss of selectivity without markedly reducing transport rates of desired penetrants. The crosslink density of the samples will be systematically varied to evaluate the posed hypothesis. Measurement of the solubility and diffusion coefficient for each penetrant will be made. The performance of the membrane in the recovery of homogeneous catalyst and the subsequent activity of the recovered catalyst are being evaluated.