Unlock instant, AI-driven research and patent intelligence for your innovation.

A kind of carboxylated cnf and preparation method thereof

A carboxylated and permanganate technology, applied in the field of carboxylated CNF and its preparation, can solve the problems of unfriendly environment, long enzymatic hydrolysis time, poor dispersibility, etc., to reduce production cost, enhance mechanical properties, and improve dispersion. sexual effect

Active Publication Date: 2022-06-28
SHAANXI UNIV OF SCI & TECH
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] CNF is mainly obtained through mechanical treatment of raw cellulose fibers, but the pure mechanical method consumes a lot of energy, and has low fiber separation efficiency and serious damage to the cellulose structure, and the prepared CNF has a small particle size. Uniform, low crystallinity, poor dispersion
To this end, scientific researchers have developed a series of biological or chemical pretreatment methods, including enzymatic hydrolysis, TEMPO catalytic oxidation, carboxymethylation, cationization, etc., but there are still the following problems: the enzyme is expensive and expensive in the enzymatic hydrolysis pretreatment process. The enzymatic hydrolysis takes a long time, the catalyst used in TEMPO catalysis is expensive and not easy to recycle, and a large amount of organic reagents are needed in the process of carboxymethylation and cationization, which is not friendly to the environment

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of carboxylated cnf and preparation method thereof
  • A kind of carboxylated cnf and preparation method thereof
  • A kind of carboxylated cnf and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0028] The preparation method of a kind of carboxylated CNF of the present invention specifically comprises the steps:

[0029] Step 1, the sulfate-bleached softwood pulp board is stirred in a hydraulic pulper for 30 minutes to disperse uniformly, and then the mass fraction of the solution is adjusted to 30% with water.

[0030] Step 2, configure 1wt% dilute sulfuric acid in a 1000mL container, add a certain amount of permanganate and pulp under stirring, the permanganate is potassium permanganate or sodium permanganate, and prepare the mass fraction of the slurry 0.8% to 1.0%, the added mass of permanganate is 0.2% to 0.5% of sulfuric acid, and the reaction is carried out at 50 to 70 DEG C for 3 to 4 hours to complete the carboxylation process of cellulose. The reaction was quenched with hydrogen peroxide to obtain a white cellulose suspension.

[0031] In step 3, the above suspension is vacuum filtered and washed with water for 3 to 5 times until the filtrate is neutral. T...

Embodiment 1

[0035] The preparation method of a kind of carboxylated CNF of the present invention specifically comprises the steps:

[0036] Step 1) The sulfate-bleached softwood pulp board is stirred in a hydraulic pulper for 30 minutes to disperse, and then the mass fraction of the pulp is adjusted to 30% with water.

[0037] Step 2) Configure 1wt% dilute sulfuric acid in a 1000mL container, add a certain amount of potassium permanganate and pulp under stirring, the mass fraction concentration of the prepared slurry is 0.8%, and the added mass of potassium permanganate is 10% of sulfuric acid. 0.2%, react at 70℃ for 3h to complete the carboxylation of cellulose. The reaction was quenched with hydrogen peroxide to obtain a white cellulose suspension.

[0038] Step 3) Filter and wash the above suspension three times until the filtrate is neutral. The upper white paste-like solid oxidation product was collected.

[0039] Step 4), taking the above product and dispersing it in deionized wa...

Embodiment 2

[0043] The preparation method of a kind of carboxylated CNF of the present invention specifically comprises the steps:

[0044] Step 1) The sulfate-bleached softwood pulp board is stirred in a hydraulic pulper for 30 minutes to disperse, and then the mass fraction of the pulp is adjusted to 30% with water.

[0045] Step 2) Configure 1wt% dilute sulfuric acid in a 1000mL container, add a certain amount of sodium permanganate and pulp under stirring, the mass fraction of the prepared slurry is 1.0%, and the amount of sodium permanganate added is 0.5% of dilute sulfuric acid. %, react at 50°C for 4h to complete the carboxylation of cellulose. The reaction was quenched with hydrogen peroxide to obtain a white cellulose suspension.

[0046] Step 3) Filter and wash the above suspension for 4 times until the filtrate is neutral. The upper white paste-like solid oxidation product was collected.

[0047] Step 4), taking the above product and dispersing it in deionized water for ultr...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
lengthaaaaaaaaaa
aspect ratioaaaaaaaaaa
diameteraaaaaaaaaa
Login to View More

Abstract

The invention relates to a carboxylated CNF and a preparation method thereof, and relates to the field of biopolymer materials. The method comprises the following steps: adding permanganate and sulfuric acid to the aqueous solution formed from pulp, and the mass of permanganate and sulfuric acid is The ratio is (0.2-0.5): 100 to obtain a slurry; react the slurry at 50-70°C to obtain a cellulose suspension; separate the product in the cellulose suspension and prepare a dispersion with water, and then Homogenized at 12-18°C to obtain carboxylated CNF, the yield can be as high as 97.6%, which can not only improve the dispersion of cellulose nanofibrils, but also enhance its mechanical properties, especially with rich carboxyl groups on the surface, can Widely used in biomedical materials, cosmetics and food and other fields.

Description

technical field [0001] The invention relates to the field of biopolymer materials, in particular to a carboxylated CNF and a preparation method thereof. Background technique [0002] In recent decades, the widespread use of non-renewable and non-degradable petroleum-derived-based materials has caused prominent environmental pollution problems, and the shortage of fossil energy has led to an urgent need to develop renewable and degradable sustainable materials to alleviate the current environmental and energy crisis. . Cellulose is the most abundant natural polymer in nature, and it is a green and environmentally friendly renewable resource. Cellulose is widely used in materials, chemicals, food, medicine, environment and other fields because of its abundant sources, low price, renewable, biodegradability and biocompatibility. [0003] Cellulose nanofibrils (English name cellulose nanofibril, abbreviated as CNF) obtained by physical or chemical treatment of cellulose are na...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C08B15/04
CPCC08B15/04
Inventor 张素风刘亚丽唐蕊华林瑞李磊魏宁
Owner SHAANXI UNIV OF SCI & TECH