Well-Defined Poly(γ-benzyl-l-glutamate)-g-Polytetrahydrofuran: Synthesis, Characterization, and Properties

The synthesis of well-defined graft copolymers of poly(γ-benzyl-l-glutamate)-g- polytetrahydrofuran, PBLG-g-PTHF, has been achieved via controlled termination of living PTHF branch chains with −NH– functional groups along PBLG macromolecular backbone. The PBLG backbone with different molecular weights (Mn = 2000–45000 g·mol–1) were prepared by anionic ring-opening polymerization of γ-benzyl-l-glutamate N-carboxyanhydrade (BLG-NCA). Living PTHF chains with predictable chain length (Mn = 720–7000 g·mol–1) were prepared by living cationic ring-opening polymerization of THF with methyl triflate (MeOTf) as an initiator. The grafting efficiency (GE) of living PTHF chains onto PBLG backbone via controlled termination reached to near 100%. The grafting density (GD) along PBLG backbone and average number of PTHF branches (Nb,PTHF) in PBLG-g-PTHF graft copolymers could be mediated by changing the molar ratio of living PTHF chains to −NH– functional groups. Circular dichroism (CD) and FTIR spectra show that some of ...