Well-defined polymethylene-based block co/terpolymers by combining anthracene/maleimide diels–alder reaction with polyhomologation

Abstract

ARTICLE This journal isA novel strategy towards well-defined polymethylene-based co/terpolymers, by combining anthracene/maleimide Diels-Alder reaction with polyhomologation, is presented. For the synthesis of diblock copolymers the following approach was applied: a) synthesis of α-anthracene-ω-hydroxypolymethylene by polyhomologation using tri (9-anthracene-methyl propyl ether) borane as initiator, b) synthesis of furan-protected-maleimide-terminated poly (ε-caprolactone) or polyethylene glycol and c). Diels-Alder reaction between the anthracene and maleimide-terminated polymers. In the case of triblock terpolymers the α-anthracene-ω-hydroxy-polymethylene was used as macroinitiator for the ringopening polymerization of D, L-lactide to afford an anthracene-terminated PM-b-PLA copolymer, followed by Diels-Alder reaction with furan-protected maleimide-terminated poly (ε-caprolactone) or polyethylene glycol to give the triblock terpolymers. All intermediate and final products were characterized by SEC, 1 H NMR, UV-VIS spectroscopy and DSC.

C1 polymerization: a unique tool towards polyethylene-based complex macromolecular architectures

“…A simple and effective method for the synthesis of PE-based diblock copolymers or triblock terpolymers was developed by our group through the Diels-Alder reaction. 49 The α-anthracene-PE-OH (diene 1), prepared by polyhomologation with tri(9-anthracenemethylpropyl ether)borane as initiator, reacted with furan-protectedmaleimide-terminated PCL-MI or PEG-MI (dienophile) to afford PE 100 -b-PCL 50 (M n,NMR = 6900 g mol -1 , Đ = 1.51) or PE 100 -b-PEG 100 (M n,NMR = 5600 g mol -1 , Đ = 1.14) diblock copolymers (Scheme 21). Interestingly, the terminal hydroxyl group of α-anthracene-PE-OH could be further transformed to diblock copolymer Ant-PE-b-PLA-OH (diene 2) though ROP using lactide as monomer in the presence of DBU as catalyst.…”

Click chemistry strategies for the accelerated synthesis of functional macromolecules

“…117 In contrast, maleimide-anthracene DA cycloaddition is often used for polymer modification with conjugation occurring at around 110 C, and remaining irreversible up to 250 C. This increased thermal stability is a driving force for applications of maleimide-anthracene click chemistry for the synthesis of graft polymers from anthracene-containing side-chains based on various types of polymer backbones, [118][119][120][121][122] in addition to the synthesis of BCPs from anthracene chain-end modified polymers and the corresponding masked maleimide block (typically as furan or thiol adducts). [123][124][125][126] In summary, classic DA reaction has been frequently used for crosslinking, network formation and selfmendable materials due to its dynamic nature. However, these systems are generally not applicable for the direct syntheses of high MW linear polymers due to relatively slow kinetics and potential reversibility.…”

“…667 Diels-Alder coupling between furan/anthrancene and maleimide building blocks has also been shown to be a strategy for the synthesis of various BCPs. 125,126 Recently, the emergence of RAFT-HDA provided a rapid and efficient route for BCP synthesis. Initial work relied on conjugating PS chains having dithioester end-groups (benzyl (diethoxyphosphoryl)dithioformate or benzyl pyridin-2-yldithioformate) with aliphatic dieneterminated polycaprolactone (PCL) at 50 C for 2-24 hr, 129 with a dramatic reaction rate improvement being achieved for cyclopentadienyl-functionalized polymers.…”

“…This increased thermal stability is a driving force for applications of maleimide‐anthracene click chemistry for the synthesis of graft polymers from anthracene‐containing side‐chains based on various types of polymer backbones, 118–122 in addition to the synthesis of BCPs from anthracene chain‐end modified polymers and the corresponding masked maleimide block (typically as furan or thiol adducts) 123–126 …”

Well-defined polyethylene-based graft terpolymers by combining nitroxide-mediated radical polymerization, polyhomologation and azide/alkyne “click” chemistry

“…The resulting star is subsequently oxidized/hydrolyzed to afford hydroxyl-end-capped linear PEs. [30][31][32][33] The hydroxylfunctionalized PE can be used directly as initiator for (ROP) [34][35] of cyclic ethers/esters or indirectly, after chemical modification, for (ATRP), [36][37][38][39] (RAFT) 40 and ring-opening metathesis polymerization (ROMP). [41][42][43] In this work, we report the synthesis of novel polyethylene-based graft terpolymers via the "grafting onto" strategy by combining NMP, polyhomologation and CuAAC "click" chemistry.…”