Hybrid Photoiniferter and Ring-Opening Polymerization Yields One-Pot Anisotropic Nanorods.

Polymerization-induced self-assembly (PISA) has emerged as a scalable one-pot technique to prepare block copolymer nanoparticles. Recently, we developed a PISA process that resulted in poly(L-lactide)-b-poly(ethylene glycol) block copolymer nanoparticles coined ring-opening polymerization-induced crystallization-driven self-assembly (ROPI-CDSA). The resulting nanorods demonstrated a strong propensity for aggregation, resulting in the formation of 2D sheets and 3D networks. Here, we report the synthesis of poly(N,N-dimethyl acrylamide)-b-poly(L)-lactide block copolymer nanoparticles by ROPI-CDSA utilizing a two-step, one-pot approach. A dual-functionalized photoiniferter was first used for controlled radical polymerization of the acrylamido-based monomer, and the resulting polymer served as a macroinitiator for organocatalyzed ring-opening polymerization to form the solvophobic polyester block. The resulting nanorods are highly stable and display anisotropy at higher molecular weights (>12k Da) and concentrations (>20% solids) than our previous report. This development expands the chemical scope of ROPI-CDSA block copolymers and provides readily accessible nanorods made with biocompatible materials. This article is protected by copyright. All rights reserved.