Efficient synthesis and self-assembly of hetero‑grafted amphiphilic polypepide bottlebrushes

Luo, Chunhui; Chen, Chongyi; Li, Zhibo

doi:10.1351/PAC-CON-12-02-07

Pure Appl. Chem., 2012, Vol. 84, No. 12, pp. 2569-2578

http://dx.doi.org/10.1351/PAC-CON-12-02-07

Published online 2012-07-26

Efficient synthesis and self-assembly of hetero‑grafted amphiphilic polypepide bottlebrushes

Chunhui Luo, Chongyi Chen and Zhibo Li*

Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China

Abstract: A new type of hetero-grafted molecular bottlebrush with polypeptide as backbone was synthesized using graft-onto strategy. Poly(γ-propargyl-L-glutamate) (PPLG) as backbone was firstly synthesized via ring-opening polymerization (ROP) of γ-propargyl-L-glutamate (PLG) N-carboxyanhydride (NCA). Next, polystyrene-N₃ (PS-N₃) and monomethoxy poly(ethylene glycol)-N₃ (mPEG-N₃) as side chains were grafted onto the PPLG backbone using copper-catalyzed click reaction, which afforded good grafting density and efficiency. Two polypeptide bottlebrushes with PS-to-mPEG molar ratio at 70/30 and 30/70 were prepared. The self-assembly behaviors of these two polypeptide bottlebrushes were investigated using the cosolvent method, and their supramolecular structures were characterized using light scattering (LS) and electron microscopy.