Synthesis of block-brush terpolymer via one-step RAFT-ROP and grafting to "click" chemistry methods

Abstract

In this contribution, well-defined poly(ɛ-caprolactone-b-4-vinylbenzyl-g-ethyleneglycol) [poly(ɛ-CL-b-VB-g-EG)] block-brush terpolymer was prepared via reversible addition/fragmentation chain transfer (RAFT), ring-opening polymerization (ROP) and grafting to “click” chemistry methods. For this purpose, in the first part, a RAFT agent was obtained by the reaction of 3-chloro-1-propanol and ethylxanthic acid potassium salt for the one-step RAFT-ROP polymerization. In the second part, the poly(ɛ-caprolactone-b-4-vinyl benzyl chloride) [poly(ɛ-CL-b-VBC)] block copolymer was prepared by RAFT polymerization of 4-vinyl benzyl chloride, and ROP of ɛ-caprolactone in the presence of RAFT agent in the one-step. In the third part, the poly(ɛ-caprolactone-b-4-vinyl benzyl-N₃) (azide-terminated) was obtained from reaction of the poly(ɛ-CL-b-VBC) block copolymer and NaN₃. Finally, the poly(ɛ-CL-b-VB-g-EG) block-brush terpolymer was prepared from the reaction PEG-propargyl, which obtained by the reaction of polyethylene glycol (PEG-3000) with propargyl chloride, and poly(ɛ-CL-b-VB-N₃) via the grafting to "click" chemistry method. The structure of the final products was characterized by methods such as GPC, ¹H-NMR, FT-IR, DSC, and SEM.