CN-122013510-A - Surface modified cellulose fiber and preparation method thereof

CN122013510ACN 122013510 ACN122013510 ACN 122013510ACN-122013510-A

Abstract

The invention provides a surface modified cellulose fiber and a preparation method thereof, wherein the surface modified cellulose fiber comprises the steps of immersing the cellulose fiber in an ionic solvent, placing the cellulose fiber in an activation temperature of 40-60 ℃ for activation treatment of 10-30 min to obtain an activated cellulose fiber, immersing the activated cellulose fiber in a vinyl ester modification reagent, placing the activated cellulose fiber in a reaction temperature of 40-60 ℃ for reaction of 1-3 h to obtain a grafted cellulose fiber, transferring the grafted cellulose fiber into an antisolvent for full washing and drying to obtain the surface modified cellulose fiber, wherein the surface modified cellulose fiber comprises a porous skin layer and a core layer from outside to inside, the inside of the porous skin layer forms a pore channel structure extending inwards from the surface, and hydroxyl grafting acetyl groups of cellulose molecular chains of the porous skin layer are used for retaining high strength mechanical properties and high-efficiency functional grafting properties.

Inventors

XU FENG
WANG YONGKUI
WANG XIAOYU
YANG XIAOGANG
ZHU KUNKUN
LI HAICHAO
Lin Runzhe
Wu Lizha

Assignees

浙江理工大学

Dates

Publication Date: 20260512
Application Date: 20260415

Claims (10)

1. A method for preparing a surface modified cellulosic fiber, comprising the steps of: Immersing cellulose fibers in an ionic solvent, and performing activation treatment at an activation temperature of 40-60 ℃ for 10-30 min to obtain activated cellulose fibers; immersing the activated cellulose fiber into a vinyl ester modifying reagent, and reacting at a reaction temperature of 40-60 ℃ for 1-3 h to obtain grafted cellulose fiber; Transferring the grafted cellulose fiber into an antisolvent, fully washing and drying to obtain the surface modified cellulose fiber.
2. The method of preparing surface modified cellulose fibers according to claim 1, wherein the ionic solvent comprises a proton type organic strong base ionic liquid and a hydrogen bond type eutectic solvent.
3. The method of preparing surface modified cellulose fibers according to claim 1, wherein the ionic solvent is one or more of 1, 8-diazabicyclo [5.4.0] undec-7-ene acetate, 1, 8-diazabicyclo [5.4.0] undec-7-ene methoxy acetate, 1, 5-diazabicyclo [4.3.0] non-5-ene succinate, 1, 5-diazabicyclo [4.3.0] non-5-ene ethoxy acetate, tetramethylguanidine-acetic acid, tetramethylguanidine-urea, or choline chloride-acetic acid.
4. The method of preparing surface modified cellulose fibers according to claim 1, wherein the vinyl ester modifying agent is selected from one or more of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl laurate, vinyl stearate, vinyl acrylate, vinyl methacrylate, vinyl bromoacetate, vinyl azidoacetate, vinyl adipate.
5. The method of preparing surface modified cellulose fibers according to claim 1, wherein the activation temperature is 50 ℃ and the activation time is 10 min.
6. The method for producing a surface-modified cellulose fiber according to claim 1, wherein the reaction temperature is 50 ℃ and the reaction time is 2 h.
7. The method of preparing surface modified cellulose fibers according to claim 1, wherein the cellulose fibers are nonionic NMMO system fibers or ionic solvent system fibers.
8. A surface modified cellulose fiber, characterized in that it is produced by the process according to any one of claims 1 to 7, comprising a porous skin layer from the outside to the inside and a core layer, wherein the inside of the porous skin layer forms a pore structure extending inward from the surface, and hydroxyl groups of cellulose molecular chains of the porous skin layer are grafted with acetyl groups.
9. The surface modified cellulosic fiber of claim 8, wherein the surface modified cellulosic fiber has a diameter of 35-45 μm.
10. The surface modified cellulose fiber according to claim 8, wherein the fiber is used in textile, filter, food processing and biomedical fields.

Description

Surface modified cellulose fiber and preparation method thereof Technical Field The invention relates to the technical field of cellulose fiber materials, in particular to a surface modified cellulose fiber and a preparation method thereof. Background Cellulose fibers such as Lyocell fibers (NMMO system), ionic solvent system fibers and the like are subjected to a dry-jet wet spinning process, and a supermolecular structure with high crystallinity and high orientation is formed through molecular chain non-covalent bond cooperative assembly, so that the composite material has excellent mechanical stability, can be completely degraded within 30-90 days in a natural composting or soil environment, and meets the requirement of green sustainable development. The primary cellulose fiber has three inherent defects, namely, the primary cellulose fiber is seriously limited to be applied to a large scale in a high-end scene, namely, the surface of the primary cellulose fiber is rich in hydroxyl groups and extremely strong in hydrophilicity, is easy to absorb moisture, soften and collapse when being used in a humid environment, for example, in a cigarette filter tip scene, moisture absorption can directly lead to out-of-control filter tip absorption resistance and greatly reduce filtration efficiency, and secondly, due to the lack of specific functional groups such as acetyl, ester groups and carbonyl groups, the primary cellulose fiber cannot form specific hydrogen bonds, pi-pi actions and hydrophobic actions with phenols and aldehydes harmful molecules in smoke, waste water, the selective adsorption capacity of the primary cellulose fiber on the harmful components is insufficient, and thirdly, the extremely low flexibility not only increases the difficulty of material forming processing, but also can cause adverse effects on performance regulation (such as filter tip absorption resistance control) of the primary cellulose fiber, and further cannot adapt to the application requirements of the primary cellulose fiber in the high-end scene such as textiles, filter equipment, food processing and biological medicine. At present, the cellulose fiber functional material is generally prepared by chemical modification (acetylation, etherification, graft copolymerization and the like) and physical modification (surface coating, blending compounding and the like) technologies in the industry, but the existing scheme still cannot break through the bottleneck of retaining mechanical properties and achieving high-efficiency functionalization. The traditional chemical modification process, such as a cellulose acetate preparation process, needs to use toxic reagents with strong corrosiveness, irritation and even potential carcinogenicity, such as acetic anhydride, concentrated sulfuric acid, methylene dichloride and the like, the reagents are difficult to fully recover, part of the reagents remain in the materials to endanger human health, limit high-end scene application, the emission can cause environmental pollution and increase environmental protection cost, and in an aqueous phase modification system, the modified reagents are easy to generate side reactions to generate impurities, so that the functional materials generate irritation peculiar smell and moisture absorption are accelerated, and meanwhile, the utilization rate of the modifier is low. In addition, due to the structural distribution characteristics of a cellulose crystallization area and a non-crystallization area, the modification reagent is difficult to realize uniform permeation and efficient grafting, so that the performance fluctuation of the prepared material is large, and excellent mechanical strength and target functional effects cannot be effectively considered. The physical modification adopts the modes of coating, blending and the like, has poor bonding fastness among components, is easy to fall off in the subsequent processing or actual use process, and further influences the stability of the material performance. In order to solve the problems, various cellulose modification optimization schemes are developed in industry successively, one scheme takes super-alkali ionic liquid as a solvent, cellulose is subjected to transesterification modification after being completely dissolved, the aim is to prepare cellulose ester derivative powder or film with high substitution degree, but the process can completely destroy hydrogen bond network among cellulose molecular chains, so that the fiber loses original high orientation and crystallization structure, the high strength chemical skeleton of original fiber is completely lost, the fiber cannot be used as structural fiber material for filtration, spinning and other scenes, the other scheme uses single aqueous solution as a reaction medium, vinyl ester reagent is adopted for carrying out surface esterification modification on cellulose, but the swelling capacity of water molecules on cellulose is extremely weak