Synthesis of Novel μ-Star Copolymers with Poly(N-Octyl Benzamide) and Poly(ε-Caprolactone) Miktoarms through Chain-Growth Condensation Polymerization, Styrenics-Assisted Atom Transfer Radical Coupling, and Ring-Opening Polymerization

Abstract

Star copolymers are known to phase separate on the nanoscale, providing useful self-assembled morphologies. In this study, the authors investigate synthesis and assembly behavior of miktoarm star (μ-star) copolymers. The authors employ a new strategy for the synthesis of unprecedented μ-star copolymers presenting poly(N-octyl benzamide) (PBA) and poly(ε-caprolactone) (PCL) arms: a combination of chain-growth condensation polymerization, styrenics-assisted atom transfer radical coupling, and ring-opening polymerization. Gel permeation chromatography, mass-analyzed laser desorption/ionization mass spectrometry, and ¹ H NMR spectroscopy reveal the successful synthesis of a well-defined (PBA₁₁ )₂ -(PCL₁₅ )₄ μ-star copolymer (M_n,NMR ≈ 12 620; Đ = 1.22). Preliminary examination of the PBA₂ PCL₄ μ-star copolymer reveals assembled nanofibers having a uniform diameter of ≈20 nm.

Keywords: chain-growth condensation polymerization; miktoarm star copolymer; poly(N-octyl benzamide); poly(ε-caprolactone); styrenices-assisted atom transfer radical coupling.