Well-defined polymers derived from L-proline are synthesized using reversible addition–fragmentation chain transfer (RAFT) polymerization and the amino acid-based polymers exhibit thermosensitive phase separation at lower critical solution temperatures (LCST = 15–45 °C) in aqueous medium.

The eutectic effect of a Li-salt and an amide is caused by the interaction between Li⁺ and CO of the amide. The reduction resistance of the amide is improved by substituting N–H with N–CH₃.