Preparing cyclic polymers from long polymer chains is challenging first because the polymer chain ends have a low probability to contact one another, and second, because end cyclization has to compete with interchain coupling. To minimize interchain coupling, cyclic polymers are usually synthesized under high dilution thereby limiting the amount of macrocycles that is prepared per unit volume of solvent. Reported here is a new methodology for preparing high molecular weight macrocycles in high purity and high polymer concentration from linear precursors. To improve on the efficiency of end cyclization, we used an ABCBA pentablock copolymer with reactive A blocks rather than a pair of end reactive groups. Our method employs the �slow addition� of a micellar solution into a reactor containing a solvent under constant stirring and UV irradiation. The �slow addition� technique is also used to prepare globule-coil tadpole copolymers in high concentration and purity from diblock copolymers.

New methodology for preparing cyclic and globule-coil (tadpole) polymers

239th National Meeting (2010)

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