Synthesis And Chiral Separation Of Poly (L - L - Glutamate)

There are many kinds of methods to get enantiomer. The separation technology of enantioselective membrane has been paid attention because of energy saving, low cost, continuous operation, easy large-scale and so on. The main works of the thesis are listed as follows:The significance and methods of enantioseparation were introduced. The chiral stationary phases in HPLC and the membrane technology were mentioned.After preparation, purification and characterization of the monomer N-carboxyanhydride of L-glutamic acid ethyl ester were performed, the polyamino acid was synthesized. The influence on the yield and viscosity of the polymer were studied by content of initiator and monomer, kinds of solvent, purity of monomer,reaction temperature, and polymerization time.Dissolving the poly(L-glutamic acid ethyl ester) in chloroform, a chiral stationary phase based on the poly(L-glutamic acid ethyl ester) coating onto silica gels were successfully prepared. The chiral column was used for the separations of four racemates and nine isomers with different ratios of hexane/isopropanol and hexane/ethanol as the mobile phase. The experimental results showed that poly(L-glutamic acid ethyl ester) possesses a good ability for separating enantiomers and isomers.The poly(L-glutamic acid ethyl ester) membranes were prepared. Besides, the influences of different parameters such as the molecular weight of membranes, the amount of acetonitrile, the concentration of feed solution, permeation time and temperature for eantioseparations of D,L-4-hydroxyphenylglycine were studied.Around 46.65% of enantiomeric excess(e.e.%) for D,L-4-hydroxyphenylglycine was obtained.