“Graft to” Modification of Lignin by the Combination of Enzyme-Initiated Reversible Addition–Fragmentation Chain Transfer and Grafting

Abstract

Reversible addition–fragmentation chain-transfer (RAFT) polymerization demonstrates promise for preparing polymers with well-controlled weights and architectures. In this study, “one enzyme double catalysis” method applied in RAFT polymerization and grafting for lignin modification was reported. Acetylacetone (ACAC) radicals were generated by horseradish peroxidase (HRP) and hydrogen peroxide (H2O2), efficiently initiating well-controlled RAFT polymerization in the presence of chain-transfer agents. In this study, two vinyl monomers were polymerized, affording polymers with a controlled molecular weight and a low-molecular-weight distribution. In addition, this new “graft to” RAFT polymerization method catalyzed by the HRP/H2O2/ACAC system was carried out on lignin to prepare biocomposites. The difference between the grafted biocomposites and raw lignin was examined by Fourier transform infrared spectroscopy, and other analysis tests. The successful combination of HRP-initiated RAFT polymerization and enzyme-catalyzed graft modification will open a new avenue for the potential green polymerization of different monomers and green preparation of functional materials.

High‐efficient surface tailoring via reverse atom transfer radical polymerization and reversible addition‐fragmentation chain‐transfer polymerization in an aqueous system initiated by a monocenter redox pair

“…Accordingly, the grafted PBMA prepared via SI-reverse ATRP showed the narrower GPC curves than those of PNIPAM in Figure 4B, the Ɖ ranging from 1.19 to 1.32 confirmed the better controllability. The grafted PNIPAM and PBMA were also analyzed by 1 H NMR spectroscopy in Figure 4C, D. In the spectroscopy of PNIPAM (Figure 4C), the chemical shift at 5.99-6.78 ppm can be assigned to the protons of N-H, the signals at 3.99 and 1.13 ppm represented the methyne and methyl protons on isopropyl groups, and the protons on the carbon chain skeleton was founded at 1.51-2.45 ppm. In Figure 4D, the chemical shifts at 0.71-1.05 ppm corresponded to the protons on the side methyl groups of PBMA, the signals at 1.34 and 1.55 ppm were attributed to the protons on the methylene groups of the n-butyl moieties, those signals at 1.68-2.02 ppm corresponded to the protons on the methylene groups of the main chain, and the chemical shift at 3.87 ppm was the protons on the methylene groups neighboring the oxygen atom in the n-butyl moieties.…”

“…Tailoring the physicochemical properties of the material surface by tethering polymer chains has become a powerful approach and has given rise to significant advances in interface engineering of heterogeneous materials. [1][2][3][4][5] Remarkably, this ubiquitous technique makes it possible to prepare various well-defined organic-inorganic hybrid particles containing segments those are incompatible at the molecular level. 6,7 Polymer chains can be prepared by "grafting to" as well as "grafting from" methods.…”

Antibacterial thyme oil-loaded zwitterionic emulsion hydrogels

“…Currently, enzyme-mediated polymerization has attracted increasing attention in the preparation of biomedical materials due to its biocompatibility, mild reaction conditions, and environmental-friendliness. 12 Horseradish peroxidase (HRP) is an enzyme extracted from the root of horseradish, which primarily consists of heme, a compound of protoporphyrin and Fe( iii ). 13 The enzyme initiation system, which is comprised of HRP, the oxidant H 2 O 2 and the polymerization mediator acetylacetone (ACAC) has been well investigated and utilized to initiate the polymerization of vinyl monomers to construct hydrogels.…”

Reaction Mechanism of Phenolic Lignin and High Concentration Chlorine Dioxide and Its Application

“…Lignin is an abundant natural resource, and significant attention has been paid to its separation, 1 , 2 modification, 3 and applications. 4 Lignin has a complex chemical structure and diverse composition and is always associated with cellulose and hemicellulose.…”

“…Lignin is an abundant natural resource, and significant attention has been paid to its separation, , modification, and applications . Lignin has a complex chemical structure and diverse composition and is always associated with cellulose and hemicellulose. , Therefore, it is helpful to understand the chemical changes and reaction mechanism of lignin at the molecular level.…”