Thermoresponsive Poly(γ-propyl-L-glutamate)-Graft-(oligo ethylene glycol)s: Synthesis, Characterization, and Properties

摘要

A series of thermoresponsive poly(γ-propyl-L-glutamate)-graft-(oligo ethylene glycol)s (PPLG-g-OEGs) with different main-chain and side-chain lengths have been synthesized via copper-mediated alkyne-azide 1,3-dipolar cycloaddition between poly(cazidopropyl- L-glutamate)s (PAPLG) and propargyl terminated oligo ethylene glycols (Pr-OEGs). Fourier transform infrared spectrometer analysis revealed that PAPLG_(10) adopted 39.4 β-sheet, 47.4 α-helix, and 13.2 random coil while PAPLG with longer mainchain length (DP=37 and 88) and PPLG-g-OEGs adopted exclusive α-helix in the solid state. Circular dichroism analysis revealed that PPLG-g-OEGs adopted a-helical conformations with helicities in the range of 50~100. The thermoresponsive behaviors of PPLG-g-OEGs in water have been studied by dynamic light scattering. The polymer concentration, main-/side-chain length, and helicity collectively affected their cloud point temperatures. VC 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41022.