Synthesis of heterotelechelic polymers by free radical addition-fragmentation chain transfer

Abstract

Telechelic polymers are polymers, generally of moderate molar masses, carrying functional groups at both chain ends. A telechelic polymer is therefore characterized by the nature and the length of the polymer chain and the nature of the functional groups. Classical telechelic polymers are linear macromolecules carrying two identical functional end‐groups. When the polymer contains two different functional groups, it is called “heterotelechelic”. During the past decade, a large number of new synthetic methods for the preparation of telechelic polymers have been proposed in the literature. Free radical addition‐fragmentation reaction has not only been reported to be a new method allowing chain‐length control, because of schematic analogy with chain transfer reaction, but has also been identified as an effective means for generating functional polymers. This review describes new developments in the radical synthesis of heterotelechelic poly(vinyl monomer)s through the use of addition‐fragmentation chain transfer agents.

Quenching of metal-catalyzed living radical polymerization with silyl enol ethers

“…36 As shown in eq 2, the propagating radical species added to the CAC double bond of 3 and was followed by fragmentation, resulting in the benzyl radical, which could initiate polymerization along with the formation of a dead chain end with a CAS double bond: 36 As shown in eq 2, the propagating radical species added to the CAC double bond of 3 and was followed by fragmentation, resulting in the benzyl radical, which could initiate polymerization along with the formation of a dead chain end with a CAS double bond:…”

Chain Transfer by the Addition-Fragmentation Mechanism. 6. Radical Polymerization toward the Synthesis of End-Functional Telomers, Macroinitiators, and Block Copolymers

“…1 H NMR (CDCl3): δ 7.50-7.20 (m, 10H, C 6H5), 5.6-5.3 (m, 3H, CH2dC and CH), 3.53 (s, 3H, OCH3), 1.60 and 1.58 (2s, 6H, C(CH 3)2). 13 3-(Cumylperoxy)-3-ethoxy-2-phenyl-1-propene (CPE-PP). To a mixture of 3,3′-diethoxy-2-phenyl-1-propene 17 (6.18 g, 30 mmol) and PTSA (10 mg, 0.06 mmol) was added dropwise, at room temperature, cumyl hydroperoxide (87%, 5.59 g, 32 mmol).…”

“…A number of chain transfer agents able to generate an additon-fragmentation process have been developed so far, and Colombani and Chaumont submitted recently a review dealing with the wide area of addition-fragmentation processes in the free radical polymerization. 13 However, the industrial valorization is still limited because of problems related mostly to the synthetic availability of these compounds at a reasonable cost. Such materials could be conveniently used for the preparation of building blocks for large structures, including block and graft copolymers, by condensation reactions.…”

“…13 C NMR (63 MHz) spectrum of polystyrene (Mn ) 2500) prepared using CPMPP as a chain transfer agent.…”

Synthesis and reactions of cysteine-based telechelic polymers

“…Telechelic polymers with functional groups are useful as reactive polymers,1 which can be used for coupling reactions to afford block copolymers and network polymers 2. Heterotelechelic polymers with two different functional groups at the polymer ends were synthesized by the free‐radical addition fragmentation chain transfer reaction 3. We reported the synthesis and radical polyaddition of N ‐4‐vinylbenzoyl‐ L ‐cysteine methyl ester (VCM) 4.…”