The Preparation And Application Of A Proline Catalyst Immobilized Polyacrylonitrile Fiber

This dissertation contains two parts.The first part: Preparation of proline functionalized polyacrylonitrile fibercatalystProline is a simple natural product. It has been applied to catalyze asymmetricreactions such as Aldol reaction, Michael addition and Mannich reaction. Proline iscommercially available, conveniently manufactured, and environmentally friendly. Butorganic solvents are often required for the catalytic reaction and the catalysts arenon-recoverable.In this research, a new method for the preparation of proline functionalizedpolyacrylonitrile fiber has been developed. Commercially available polyacryonitrilefiber was refluxed in an ethylenediamine aqueous solution to produce the aminated fiber.Then the aminated fiber was alkylated with4-bromo-L-proline resulting in a prolinecovalently immobilized fiber catalyst. The best reaction conditions were found byoptimizing the amounts of reactants, reaction time, reaction temperature and thesolvents. The produced fiber catalyst maintained more than50%of its original breakingstrength. The fiber catalyst was characterized by mechanical properties, elementalanalysis, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) andFourier-transfer infrared spectroscopy (FTIR). The proline immobilization was wellsupported by the data of characterization.The second part: The application of proline functionlized polyacrylonitrile fibercatalystThe proline functionlized polyacrylonitrile fiber catalyst was applied to catalyzeAldol reactions. The best reaction conditions were found by optimizing the catalystloading, reaction time, reaction temperature and the solvents. Aldol reactions couldproceed completely with catalyst loading (2-10mol%) in water within48h. This fibercatalyst was applicable for different substrates. This catalytic system has the advantagesof low catalyst loading, short reaction time, high activity and using environmentalfriendly solvent. All the synthesized intermediates and target compounds were characterized by1HNMR.