Study on the Tunable LCST Properties of Phenylalaninate Derivative with Branching Oligoethyleneoxy Chains

Thermosensitive amino acid derivative with oligoethyleneoxy chains with tunable lower critical solution temperature (LCST) were prepared from L-methyl phenylalaninate and 3,5-diaminobenzoic acid derivative with oligoethyleneoxy chains. The solution properties and the effects of salt ion species on LCST of phenylalaninate derivative 11 were investigated by UV-vis. The results indicate that the LCST value of 11 could be controlled by adjusting the salt concentration with different cationic species.