The ring-opening polymerization behavior of five-membered lactones fused to a cyclohexane ring, T6L and C6L, was investigated under various conditions. The t-BuOK-initiated anionic polymerization of T6L produces polymers having Mn values of 5000. In remarkable contrast, C6L did not polymerize at all, implying the increase in ring strain of the lactone ring by trans-fused cyclohexane. The anionic polymerization of T6L was reversible, and the thermodynamic parameters characterizing the polymerization of T6L were estimated to be ΔHp°=−18 kJ·mol−1 and ΔSp°=–65 J·K−1mol−1.
- Osamu Haba
- Hiroki Itabashi
