Three cyclic oxoester-thioester hybrid monomers were studied for anionic and cationic ring-opening polymerizations. Anionic polymerizations using thiol with 2,6-lutidine were successful for the chemoselective cleavage of the thioester with the thiol propagating end, exhibiting the living character to some extent. The polymerization in 2,6-lutidine without an initiator produced macrocyclic polymers. The cationic polymerizations occurred with the aid of CF3SO3H and benzyl alcohol but involved side reactions with low chemoselective ring cleavage. The thioester unit caused the polymers to exhibit a lower Tg with greater thermal and photo degradability.
- Mao Hirata
- Tomoki Yoshimatsu
- Masato Suzuki