Preparation of tailor-made functional polymers by anionic living polymerization.

Anionic living polymerization is the most excellent method to prepare homopolymers and block polymers with controlled molecular weights and very narrow molecular weight distributions. However, functional monomers are unable to be directly polymerized with anionic initiators to generate functional polymers of well-defined structures because initiators and propagating ends react with the functional groups. Recently, it was found that styrene derivatives bearing functional groups, such as hydroxyl, amino, formyl, and carboxyl groups, were polymerized with anionic initiators to afford living polymers at low temperature by masking the functional groups with trialkylsilyl groups and other suitable protective groups. Removal of the protective groups was quantitatively performed by acid treatment of the polymers produced. Thus, by means of protection method and anionic living polymerization, tailor-made functional homopolymers and block copolymers of these functional monomers with styrenes and dienes were synthesized. Various types of microphase separation of the functional block copolymers were observed by electron microscopic measurement.