Unprecedented Sequence Control and Sequence‐Driven Properties in a Series of AB‐Alternating Copolymers Consisting Solely of Acrylamide Units

Abstract

Herein, we report a method to synthesize a series of alternating copolymers that consist exclusively of acrylamide units. Crucial to realizing this polymer synthesis is the design of a divinyl monomer that contains acrylate and acrylamide moieties connected by two activated ester bonds. This design, which is based on the reactivity ratio of the embedded vinyl groups, allows a “selective” cyclopolymerization, wherein the intramolecular and intermolecular propagation are repeated alternately under dilute conditions. The addition of an amine to the resulting cyclopolymers afforded two different acryl amide units, i.e., an amine‐substituted acryl amide and a 2‐hydroxy‐ethyl‐substituted acryl amide in alternating sequence. Using this method, we could furnish ten types of alternating copolymers; some of these exhibit unique properties in solution and in the bulk, which are different from those of the corresponding random copolymers, and we attributed the differences to the alternating sequence.

Alginate-g-PNIPAM-Based Thermo/Shear-Responsive Injectable Hydrogels: Tailoring the Rheological Properties by Adjusting the LCST of the Grafting Chains

“…This is likely due to the heterogeneity of the monomer composition in the copolymers, arisen from the conventional free radical polymerization method. The NtBAM content is an average value, and the sample is constituted of a mixture of statistical copolymers with NtBAM-richer and NIPAM-richer rather than the average value compositions [22,30]. The cloud point temperature (T cp ) was defined as the temperature where the optical density of the studied polymer solution increases promptly.…”

Unraveling Sequence Effect on Glass Transition Temperatures of Discrete Unconjugated Oligomers

“…that are far superior to the corresponding copolymers with random monomer sequences. [8,[14][15][16][17][18][19][20][21][22][23] It has been demonstrated that the copolymers of poly(lactide-co-glycolic acid) with unique sequences of lactide and glycolic acid possess specific hydrolysis patterns and degradation rates. [4,[24][25] Furthermore, precisely positioned reactive functional monomers in the polymer chain could allow generation of folded polymers to prepare diverse macromolecular origamis or polymer nanoparticles.…”

2,5‐Dimethylfuran/Acrylonitrile as Latent Monomer for Sequence‐Controlled Copolymer and Sequence‐Dependent Thermo‐Responsivity

“…[ 11–13 ] Comparing with the copolymer with random structure, the alternating copolymer showed more sensitivity in response to the thermal stimulation. [ 14,15 ] Though promising, the low selectivity of the comonomer addition during chain growth hindered the sequence control over the polymerization, especially for chain growth mechanism. [ 16–22 ]…”

“…[ 23,24 ] For example, Sawamoto et al. developed concurrent tandem catalysis‐based methodology, [ 25–28 ] template‐initiator, [ 29,30 ] template‐monomer strategies [ 14,15,31–34 ] for generating the sequence‐controlled polymers. Kamigaito et al.…”