One‐step synthesis of block‐graft copolymers via simultaneous reversible‐addition fragmentation chain transfer and ring‐opening polymerization using a novel macroinitiator

Abstract

One‐step synthesis of block‐graft copolymers by reversible addition‐fragmentation chain transfer (RAFT) and ring‐opening polymerization (ROP) by using a novel initiator was reported. Block‐graft copolymers were synthesized in one‐step by simultaneous RAFT polymerization of n‐butylmethacrylate (nBMA) and ROP of ε‐caprolacton (CL) in the presence of a novel macroinitiator (RAFT‐ROP agent). For this purpose, first epichlorohydrin (EPCH) was polymerized by using H2SO4 via cationic ring‐opening mechanism. And then a novel RAFT‐ROP agent was synthesized by the reaction of potassium ethyl xanthogenate and polyepichlorohydrin (poly‐EPCH). By using the RAFT‐ROP agent, poly[CL‐b‐EPCH‐b‐CL‐(g‐nBMA)] block‐graft copolymers were synthesized. The principal parameters such as monomer concentration, initiator concentration, and polymerization time that affect the one‐step polymerization reaction were evaluated. The block lengths of the block‐graft copolymers were calculated by using 1H‐nuclear magnetic resonance (1H NMR) spectrum. The block length could be adjusted by varying the monomer and initiator concentrations. The characterization of the products was achieved using 1H NMR, Fourier‐transform infrared spectroscopy, gel‐permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, elemental analysis, and fractional precipitation (γ) techniques. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2651–2659

Synthesis and characterization of poly(vinyl chloride-graft-2-vinylpyridine) graft copolymers using a novel macroinitiator by reversible addition-fragmentation chain transfer polymerization

“…Hence, it may be expected that they have shorter poly(2-vinylpyridine) segments, which is confirmed by a decrease in the molecular weights of the graft copolymers, as shown in Table 1. The same situation was also observed in our previous articles (58)(59)(60). Increasing the amount of monomers also generally causes an increase in both the yield and the molecular weights of the copolymers as expected.…”

“…At higher amounts of monomer, a deviation from normal behavior was observed. This situation could be attributed to the increase in viscosity of the polymerization medium as shown in our previous articles (24,60). Dependence of 2-vinylpyridine concentration on M n for the copolymerization is shown in Figure 3.…”

“…Polymers of a well-defined structure and molecular weight can be synthesized by controlled radical-polymerization methods, such as nitroxide-mediated polymerization (37,38), atom-transfer radical polymerization (25,(39)(40)(41)(42)(43)(44), and reversible addition-fragmentation chain transfer (RAFT) polymerization (33,(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60). RAFT polymerization is one of the most recently developed controlled radical-polymerization methods and is an important technique for the synthesis of copolymers.…”

Design and synthesis study of the thermo‐sensitive copolymer carrier of penicillin G acylase

“…Meanwhile, the research on poly (N‐isopropylacrylamide) (PNIPAM) block copolymer is more systematic and in‐depth . However, due to its poor biocompatibility and low LCST, it has seriously affected its future application prospects. Recent studies have shown that the biocompatibility of poly ( N N ‐diethylacrylamide) (PDEA) is far superior to that of PNIPAM, and its LCST is also higher than that of PNIPAM.…”

Thermal Characterization of “Comb‐Like” Block Copolymers Based on PCL Obtained by Combining ROP and RAFT Polymerizations

“…In the last years, ROP have been combined with other polymerization processes in order to obtain polymers with specific properties. For example, RAFT and ROP have been employed in a one‐step route to synthesize well‐defined copolymers . The reaction is mediated by a bifunctional compound (i.e.…”