Design and Synthesis of a Cyclic Double-Grafted Polymer Using Active Ester Chemistry and Click Chemistry via A “Grafting onto” Method

Abstract

Combing active ester chemistry and click chemistry, a cyclic double-grafted polymer was successfully demonstrated via a “grafting onto” method. Using active ester chemistry as post-functionalized modification approach, cyclic backbone (c-P2) was synthesized by reacting propargyl amine with cyclic precursor (poly(pentafluorophenyl 4-vinylbenzoate), c-PPF4VB6.5k). Hydroxyl-containing polymer double-chain (l-PS-PhOH) was prepared by reacting azide-functionalized polystyrene (l-PSN3) with 3,5-bis(propynyloxy)phenyl methanol, and further modified by azide group to generate azide-containing polymer double-chain (l-PS-PhN3). The cyclic backbone (c-P2) was then coupled with azide-containing polymer double-chain (l-PS-PhN3) via CuAAC reaction to construct a novel cyclic double-grafted polymer (c-P2-g-Ph-PS). This research realized diversity and complexity of side chains on cyclic-grafted polymers, and this cyclic double-grafted polymer (c-P2-g-Ph-PS) still exhibited narrow molecular weight distribution (Mw/Mn < 1.10).

Direct observation of the formation of a cyclic poly(alkyl sorbate) via chain‐growth polymerization by an N‐heterocyclic carbene initiator and ring‐closing without extreme dilution

“…[15] These results prompted us to perform a microscopic observation of the cyclic structures directly in order to prove the reliability of this new synthetic strategy, even though recent progress of ringclosure under diluted condition using click chemistry is still active. [25,26] In this study, we thus prepared graft-like cyclic polymers with thick chain width to prove the generation of cyclic polymers in our synthetic strategy by transmittance electron microscopy (TEM) observation. The Nheterocyclic carbene NHCtBu was used to initiate the anionic polymerization of MS in toluene (−20 C) with an addition of the bulky MAD to afford cyclic poly(MS)s having an M n of 20.5 × 10 3 -48.7 × 10 3 and narrow molecular dispersity index (M w /M n = 1.0 8 -1.4 3 ).…”

“…[ 15 ] These results prompted us to perform a microscopic observation of the cyclic structures directly in order to prove the reliability of this new synthetic strategy, even though recent progress of ring‐closure under diluted condition using click chemistry is still active. [ 25,26 ]…”

Constructing a Library of Doubly Grafted Polymers by a One-Shot Cu-Catalyzed Multicomponent Grafting Strategy

“…However, this route has never been utilized to synthesize doubly grafted polymers because it is just too difficult to incorporate two different bulky macromonomers to the precursor polymer backbone with high grafting density. Therefore, Zhang’s group suggested a smart alternating method where macromonomers containing a symmetric bis-poly­(styrene) (PS) moiety and an azide group (in the middle of the whole PS backbone) underwent the graft-to click reaction to the cyclic precursor polymer having alkynes (Figure c) . Again, multiple postmodifications on the polymer were necessary to synthesize doubly grafted polymers.…”

“…Therefore, Zhang's group suggested a smart alternating method where macromonomers containing a symmetric bis-poly(styrene) (PS) moiety and an azide group (in the middle of the whole PS backbone) underwent the graft-to click reaction to the cyclic precursor polymer having alkynes (Figure 2c). 36 Again, multiple postmodifications on the polymer were necessary to synthesize doubly grafted polymers. Overall, to broaden the utility and application of these new classes of complex polymers, a more general, diverse, efficient, versatile, and selective grafting method in a one-shot fashion with high fidelity is desirable.…”

Preparation, Characterization of Propargyl Terminal Polybutadiene and Its Crosslinked Elastomers Properties

“…The findings revealed some fundamental features of polytriazole crosslinking elastomer prepared by CuAAC reaction.Polymers 2020, 12, 748 2 of 11 complex of CuBr and PMDETA (n,n,n ,n ,n -pentamethyldiethylenetriamine) as a catalyst. Under a nitrogen atmosphere, the mixture solution was stirred at ambient temperature for 1.5 h, achieving a hydroxyl-containing double-chain polymer [10]. Similarly, Shingu first dissolved CuBr and PMDETA in DMF (dimethylformamide) solvent, and then a solution of triazido-triethynyl-containing polymer in DMF was added into the solution, using a syringe pump, at an extremely slow rate, at 100 • C, under a nitrogen atmosphere.…”