CN-122013581-A - Application of supermolecule eutectic solvent in inhibiting lignin condensation color development

Abstract

The invention relates to the technical field of high-valued utilization of cellulose raw materials, in particular to application of an supermolecule eutectic solvent in inhibiting lignin condensation color development, wherein the supermolecule eutectic solvent comprises a hydrogen bond acceptor, a hydrogen bond donor and polyalcohol. Compared with the traditional fractionation system, the system can obviously inhibit the generation of the color development byproducts, and directly obtain the cellulose with the color from cream white to white. Meanwhile, the method has mild conditions, the solvent can be recycled, and subsequent chemical bleaching is not needed, so that the obtained white cellulose can be directly used as a natural functional filler of cosmetics (especially sun cream). In conclusion, the invention provides a green and efficient solution for obtaining the light-colored bio-based cellulose, and has wide application prospect and important popularization value in the fields of chemicals, biological materials and the like.

Inventors

• ZHANG JIAHENG
• CHEN JIAWEN
• LI JIANMIN
• LI YUANBIN
• LIU NANHUI

Assignees

• 深圳杉海创新技术有限公司

Dates

Publication Date

20260512

Application Date

20260206

Claims (10)

1. 1. Use of a supermolecular eutectic solvent for inhibiting lignin condensation color development, wherein the supermolecular eutectic solvent comprises a hydrogen bond acceptor, a hydrogen bond donor, and a polyol.
2. 2. The use of the supermolecule eutectic solvent according to claim 1, wherein the hydrogen bond acceptor comprises at least one of choline chloride, betaine hydrochloride, L-carnitine, acetyl carnitine, taurine, L-arginine, choline derivative, proline, alanine and glycine and derivatives thereof, the hydrogen bond donor comprises at least one of quaternary ammonium salt, polyalcohol, organic acid and sugar, and the polyalcohol comprises at least one of aliphatic polyalcohol or sugar alcohol containing C2-C6.
3. 3. Use of the supramolecular eutectic solvent according to claim 1, wherein the polyol comprises at least one of ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, glycerol, xylitol, sorbitol, mannitol, erythritol, maltitol.
4. 4. The use of the supermolecule eutectic solvent according to claim 1, wherein the mass ratio of hydrogen bond acceptor, hydrogen bond donor and polyalcohol is 1:9 (0-9) to 9:1 (0-9).
5. 5. The use of the supermolecule eutectic solvent according to claim 1, wherein the hydrogen bond acceptor is choline chloride or betaine and derivatives thereof, the hydrogen bond donor is citric acid or malic acid, the polyalcohol is sugar alcohol, and the mass ratio of the choline chloride or betaine and derivatives thereof, the citric acid or malic acid and the sugar alcohol is 1:3:1.
6. 6. The use of the supermolecule eutectic solvent for inhibiting lignin condensation color development according to claim 1, wherein the preparation method of the supermolecule eutectic solvent comprises the steps of mixing a hydrogen bond acceptor, a hydrogen bond donor and a polyol, heating and stirring to obtain the supermolecule eutectic solvent.
7. 7. Use of the supramolecular eutectic solvent according to claim 6, wherein the stirring temperature is 70-90 ℃ for 1-3 hours.
8. 8. A method for inhibiting lignin condensation color development using a supermolecular eutectic solvent, the method comprising the steps of: mixing a hydrogen bond acceptor, a hydrogen bond donor and a polyol, heating and stirring to obtain the supermolecule eutectic solvent; Mixing the supermolecule eutectic solvent with water to obtain a water-containing supermolecule eutectic solvent; Mixing the crushed and dried cellulose raw material with the aqueous supermolecule eutectic solvent, and stirring to complete the condensation color development of lignin in the cellulose extraction process of the cellulose biomass raw material.
9. 9. A cellulosic biomass feedstock treated by the method of claim 8.
10. 10. Use of the cellulosic biomass feedstock of claim 9 in the cosmetic field.

Description

Application of supermolecule eutectic solvent in inhibiting lignin condensation color development Technical Field The invention relates to the technical field of high-value utilization of cellulose raw materials, in particular to application of an supermolecule eutectic solvent in inhibiting lignin condensation color development. Background Traditional industrial pulping and biomass fractionation processes, such as the sulfate process and various strong acid pretreatment techniques, are typically performed under severe conditions of high temperature, high pressure, strong acid or strong base, with the aim of achieving efficient separation of lignin from cellulose. However, such processes have long faced a significant technical bottleneck in that the resulting cellulosic products are dark in color, often dark brown or tan. This color problem severely restricts the application of this type of cellulosic material in cosmetic additives, food grade packaging, high grade paper and other high end fields where visual appearance and whiteness are critical. Studies have shown that the colour depth of cellulose products does not originate from simple physical contamination, but rather is closely related to the deep chemical conversion of lignin that occurs during fractionation. Under the condition of acid catalysis, the hydroxyl (C alpha-OH) at the alpha position of the side chain of the lignin structural unit is easy to generate protonizing and dehydrating, so as to generate the benzyl carbocation intermediate with high reactivity. The intermediate, as a strong electrophile, attacks the electron-rich aromatic ring of the lignin molecule itself, and undergoes electrophilic aromatic substitution reaction, thereby forming a new c—c bond (i.e., cα -Caryl condensation bond) (see Li et al, nature 2024). Such disordered intermolecular condensation reactions result in lignin conversion to highly crosslinked, structurally complex macromolecular polymers accompanied by the formation of strong chromophore groups of quinoid structure and extended conjugated systems, which macroscopically appear as a sharp darkening of the material until it becomes black or dark brown. These dark condensed lignin byproducts, which are generated in situ during fractionation, are difficult to remove by conventional physical methods because they are tightly bound to the cellulose fiber surface as they are formed. To improve the color of the product, the industry currently generally relies on subsequent chemical bleaching processes, such as chlorine bleaching, hydrogen peroxide bleaching, and the like. However, the bleaching process itself has various disadvantages in that not only energy consumption is high, but also toxic wastewater containing chlorine-containing organic matters and the like may be generated to bring about environmental treatment pressure, and meanwhile, severe chemical treatment may damage cellulose molecular chains to reduce the polymerization degree, thereby affecting the mechanical strength and the functional characteristics of the final product. Therefore, developing a green and mild fractionation technology capable of avoiding or effectively inhibiting the generation of color development byproducts from the reaction source, so as to directly obtain high-quality cellulose with light color and luster, becomes a key technical problem to be broken through in the field. Disclosure of Invention In view of the shortcomings of the prior art, the invention provides application of an supermolecule eutectic solvent in inhibiting lignin condensation color development, so as to solve the problem that efficiency, environmental protection and product color are difficult to be compatible in the lignin fractionation process in the prior art. The technical scheme adopted by the invention for solving the technical problems is as follows: in a first aspect of the invention, there is provided the use of a supermolecular eutectic solvent comprising a hydrogen bond acceptor, a hydrogen bond donor and a polyol for inhibiting lignin condensation color development. Optionally, the hydrogen bond acceptor comprises at least one of choline chloride, betaine hydrochloride, L-carnitine, acetyl carnitine, taurine, L-arginine, choline derivatives, proline, alanine and glycine and derivatives thereof, the hydrogen bond donor comprises at least one of quaternary ammonium salts (urea), polyalcohols (glycerol, ethylene glycol), organic acids (lactic acid, citric acid), saccharides (glucose, fructose), and the polyalcohols comprise at least one of aliphatic polyols or sugar alcohols containing C2-C6. Optionally, the polyol comprises at least one of ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, glycerol, xylitol, sorbitol, mannitol, erythritol, and maltitol. Optionally, the mass ratio of the hydrogen bond acceptor, the hydrogen bond donor and the polyol is 1:9 (0-9) to 9:1 (0-9). Preferably, the hydrogen bond acceptor is choline chloride or betain