Recent advances in alternating copolymers: The synthesis, modification, and applications of precision polymers

Abstract

Alternating copolymers represent a special class of copolymers, in which the two comonomers copolymerize in a regular alternating sequence along the chain. Their interesting physical and chemical properties, as well as the underlying mechanism, have attracted significant attention in both academia and industry. The electron-donor benzylidene monomers-styrene and stilbene, readily form alternating copolymers with the electron-acceptor monomersmaleic anhydride and N-substituted maleimides. The rich chemistry of the substitution groups on these monomers offers enormous combinations for the synthesis of alternating copolymers for different applications. In this paper, we aim to provide a general overview of recent publications on the specific field of these benzylidene-containing alternating copolymers, and the emphasis is placed on the synthetic progress, structure-property relationships, and the applications of these copolymers.

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

“…Figure 6B shows the 1 HNMR spectrum of the product after the treatment with n-BuNH 2 and corresponding random copolymer.T he spectrum is quite similar to that of the 1:1r andom copolymer, and an analysis of the peak integration ratios indicated a1 :1 ratio of the two units. Furthermore,F igure 5C shows the 13 CNMR spectrum of the obtained copolymer in comparison with the random copolymer, and the spectra exhibit almost identical shapes and peaksplitting patterns.P eculiar peaks specifically due to the alternating sequence were not observed, though 13 CNMR spectroscopy of the alternating copolymer was different from random ones,and it clarified the sequence in previous works of sequence control. [23,24,26,33] On the other hand, we recorded quite different MALDI-TOFm ass spectra [34] from the product after cleavage with nbutylamine to the random copolymer ( Figure 5D).…”

“…An alternating copolymer (left) that consists only of one type of repeatingunit (acryl amide) with different substituents in comparison with the corresponding random copolymer (right). al arge difference in electron density between the two monomers, [13][14][15][16][17][18][19] or by addition of aL ewis acid to an electron-poor comonomer in order to further deplete electron density. [20,21] It is thus easy to understand that achieving genuine sequence control in the copolymerization of one type of monomer with different pendants is very challenging.…”

Enhanced Fluorescence Properties of Stilbene‐Containing Alternating Copolymers

“…It is well known that electron‐deficient maleic anhydride and maleimide monomers can readily form alternating copolymers with electron‐rich monomers such as styrene, α‐methyl styrene, stilbene, vinyl acetate, etc . Of particular interest in our group are the stilbene‐maleic anhydride/maleimide alternating copolymers . First prepared by Wagner‐Jauregg in 1930, the stilbene‐maleic anhydride copolymer was regarded to be the earliest reported synthetic copolymer in literature .…”

Synthesis and Ozone Degradation of Alternating Copolymers ofN‐Substituted Maleimides with Diene Monomers

“…Electron‐accepting maleic anhydride (MAn) and N ‐substituted maleimides (RMIs) readily provide alternating copolymers by radical copolymerization with electron‐donating olefins, such as styrenes, vinyl ethers, isobutene, and other several olefins . The produced MAn copolymers are used as functional polymers, such as paints, industrial resins, sizing agents for paper, surface active agents, additives for food, anticancer drugs, and so on .…”