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

Abstract

Sequence control has attracted increasing attention for its ability of regulating polymer property and performance. Herein, the sequence‐controlled polymer containing acrylonitrile (AN) is achieved by using 2,5‐dimethylfuran/acrylonitrile adduct as a latent monomer. The temperature‐dependent retro Diels–Alder reaction is engaged in controlling the release of AN during RAFT polymerization, that is, regulating the instant AN concentration via a non‐invasive and in situ manner. Such control over the instant AN concentration and particularly the molar ratio of comonomer pair leads to the simultaneous change of monomer units in “living” polymeric chain, thus resulting in the sequence–controlled polymeric structures. By delicately manipulating the polymerization temperature, diverse sequence‐on‐demand structures of AN‐containing copolymers, such as poly(AN/methyl methacrylate), poly(AN/styrene), poly(AN/butyl acrylate), poly(AN/N,N‐dimethylacrylamide), and poly(AN/N‐isopropylacrylamide) are created. Meanwhile, this study presents an initial attempt in tuning the thermal responsivity of poly(AN/N‐isopropylacrylamide), which is closely correlated to the sequence of polymer structure. More importantly, the polymer with averagely distributed AN units results in the higher thermal sensitivity. Therefore, the synthetic strategy proposed in this work offers a promising platform for accessing the sequence‐controlled copolymers containing AN structures, thus expanding the investigation on the relationship between the polymer structures and correlated properties.

2,2‐Bistrifluoromethyl‐4,5‐difluoro‐1,3‐dioxole‐co‐tetrafluoroethylene copolymers with different compositions: Synthesis, chain and condensed matter structures and optical properties

“…The composition relationships for copolymers were derived by early workers as follows 36,37 where F 1 is the molar fraction of monomer 1 in copolymers, f 1 is the molar fraction of monomer 1 in the feed monomers, and r 1 and r 2 are the reactivity ratios of monomer 1 and monomer 2, respectively.…”

“…The copolymer chain stiffness depends on the chemical structure and the condensed matter structure of the copolymer determined by the monomer molecular structure and the monomer sequence distribution in the copolymer backbones. Precise modulating the sequence structure and exploring the relationship between condensed matter structure and properties were essential for perfluorinated copolymers 36,40,41 . The glass transition temperatures ( T g ) of PDD‐TFE copolymers with different compositions are shown in Figure 5.…”

“…Precise modulating the sequence structure and exploring the relationship between condensed matter structure and properties were essential for perfluorinated copolymers. 36,40,41 The glass transition temperatures (T g ) of PDD-TFE copolymers with different compositions are shown in Figure 5. It can be observed that the T g of the copolymers increased rapidly with the increase of F PDD , indicating that the stiffness of the copolymer chains increased significantly as more PDD was incorporated into the copolymer.…”