Precise Synthesis and Characterization of Tadpole-Shaped Polystyrenes with High Purity

Tadpole-shaped polystyrenes (PS) were successfully synthesized anionically by coupling reaction between ring polystyrene with two functional groups and living linear polystyrenes. Crude coupling product was confirmed to include unreacted linear tail polymer and tadpole polymer having one tail (single-tail tadpole polymer) and two tails (twin-tail tadpole polymer) by SEC analysis. In order to isolate the tadpole polymers, interaction chromatography (IC) was conducted to remove the linear polymer from the crude product; subsequently, two kinds of tadpole polymers were carefully separated by SEC fractionation. It has been found by SEC-MALS that the absolute molecular weights of the two fractionated products agree well with the sums of the component ring and linear chains, which prove two tadpole polymers, i.e., single-tail and twin-tail, were obtained as designed. It was confirmed that the two tadpole polymers have high molecular weight (58k for ring and 67k for a tail), narrow molecular weight distribution (Mw/Mn = 1.01), and high purity over 99% by rigorous HPLC analyses.