POLYMER-BOUND CHIRAL POLYMERS FOR USE IN ENANTIOMER SEPARATIONS

A new kind of chiral stationary phase was prepared by immobilization of the synthetic chiral polymer poly(N-acryloyl-S-phenylalanine ethyl ester) in macroporous polymer particles. Immobilization greatly improved the chromatographic performance of the chiral polymer almost without loss of selectivity. Rigid, macroporous particles were prepared by suspension polymerization of trimethylolpropane trimethacrylate. The chiral polymer was introduced into these particles by polymerizing the chiral monomer in their pore system. Immobilization was obtained by copolymerization with unreacted double bonds present in the matrix particles. Composite particles were prepared with up to 40% (w/w) of chiral polymers. The new materials, and materials prepared using alternative immobilization techniques, were evaluated for their use in chromatography with racemic compounds. The results suggest that enantioselectivity is dependent on the conformational freedom or flexibility of the chiral polymer.