Thermoresponsive poly(γ‐propyl‐l‐glutamate)‐graft‐(oligo ethylene glycol)s: Synthesis, characterization, and properties

Abstract

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(γ‐azidopropyl‐L‐glutamate)s (PAPLG) and propargyl terminated oligo ethylene glycols (Pr‐OEGs). Fourier transform infrared spectrometer analysis revealed that PAPLG10 adopted 39.4% β‐sheet, 47.4% α‐helix, and 13.2% random coil while PAPLG with longer main‐chain 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 α‐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. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41022.

Synthesis, Characterization, and thermoresponsive properties of Helical Polypeptides Derivatized from Poly(γ−4‐(3‐chloropropoxycarbonyl)benzyl‐L‐glutamate)

“…Deionized water (DI H 2 O) was obtained from Aquapro AR1–100L‐P11 water‐purification‐system (Ever Young Enterprises Development, P. R. China). L ‐Glutamic acid copper salt and propargyl terminated oligo‐ethylene‐glycols (Pr‐OEG m , m = 2 and 3) were synthesized by reported procedures …”

“…For example, high molecular weight polymethacrylamides used in long‐circulating delivery systems were not able to eliminate from the organisms (e.g., kidney), thus, they accumulated in the body and lead to toxic side effects . Recently, thermoresponsive polypeptides have gained significant attention due to their promising properties including biodegradability, biocompatibility and considerable chemical diversity with regard to the numerous amino acids (e.g., L ‐glutamic acid, L ‐lysine, and L ‐cysteine) . The covalent modification of polymers using poly(ethylene glycol) (PEG), namely peglation, has achieved interesting properties, such as nontoxicity and thermoresponsive property .…”

Water‐Soluble Thermoresponsive α‐Helical Polypeptide with an Upper Critical Solution Temperature: Synthesis, Characterization, and Thermoresponsive Phase Transition Behaviors

“…[20][21][22] While water-soluble thermoresponsive polypeptides with LCSTs have been developed by incorporation of oligo-ethylene-glycols in the side chains via directly ring-opening polymerization (ROP) of peglated amino acids-based N -carboxyanhyrides (NCAs) [23][24][25] or post-polymerization through click chemistry. [26][27][28] The molecular design of water-soluble thermoresponsive polypeptides with a UCST still remains unclear.…”

Thermoviscosifying polymers based on polyether prepared from inverse emulsion polymerization

“…Numerous methods were successively developed for preparing TVPs to endow polymer solutions with thermothickening ability, besides graft modification in organic solvent, free radical copolymerization in bulk monomers, or different media such as aqueous solution, dodecane dispersion, micellar solution were also developed. In addition, the living radical polymerization was also employed to synthesize TVPs.…”