Method for preparing cellulose water-based solution by stalk

A technology of cellulose and crude cellulose, which is applied in the field of chemical separation, can solve the problems of single source of cellulose, achieve the effect of overcoming single raw material, reducing black liquor, and being conducive to the full utilization of resources

Inactive Publication Date: 2009-06-17
UNIV OF SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, at present, the cellulose used in the research of dissolving cellulose in alkaline water solvent system is cotton linters

Method used

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  • Method for preparing cellulose water-based solution by stalk
  • Method for preparing cellulose water-based solution by stalk
  • Method for preparing cellulose water-based solution by stalk

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] 9.79 g of dewaxed wheat straw powder was added into the reactor, and then 100 ml of aqueous hydrochloric acid solution with a concentration of 2 mol / L was added, and then reacted at 100° C. for three hours. After cooling, filter and wash the filter cake with deionized water. Then it was added into 100 ml of 3.0% aqueous sodium hydroxide solution, and reacted at 100° C. for three hours. Then filter and wash. The filter cake was added to a mixed aqueous solution of 3.0% hydrogen peroxide and 5.0% acetic acid, and reacted at 60° C. for one hour. The obtained residue was washed and dried to obtain cellulose powder.

[0033] figure 2 Shown is the FT-IR spectrum of the obtained cellulose, and the IR spectra of straw raw material, different processing stages and pure cellulose are also given on this figure for comparison. It can be seen that the characteristic vibration absorption of cellulose, hemicellulose and lignin exists in the infrared spectrum of straw raw material...

Embodiment 2

[0037] Take 20 grams of dewaxed and dried bagasse, add it into 20 milliliters of 2 mol / liter hydrochloric acid aqueous solution, and react at 100° C. for 3 hours. After cooling, filter and wash to obtain residue I. The residue was added to 200 ml of 3% aqueous sodium hydroxide solution and reacted at 100°C for 2 hours. After cooling, filtration and washing afforded residue II. The residue II was added to 30 ml of 3% aqueous hydrogen peroxide to react for 1 hour. After drying, pure cellulose was obtained with a molecular weight of 32×10 4 g / mol. Add dry cellulose to 1-3M hydrochloric acid aqueous solution, react at 20-50 degrees for 2-4 hours, then filter and wash to obtain pure cellulose with molecular weight adjustment, and its viscosity-average molecular weight ranges from 8×10 4 -20×10 4 Between g / mol.

[0038] Add the obtained cellulose to the lithium hydroxide / urea (or thiourea) complex aqueous solution, stir for 30 minutes, put it in a refrigerator at -20°C for 12 ...

Embodiment 3

[0040] Dried rice straw powder was extracted with toluene-ethanol (2:1, v / v) in a Soxhlet extractor for 6 hours for dewaxing. Afterwards, 10 grams of dried samples were added to 250 milliliters of 3% hydrochloric acid aqueous solution, and reacted at 100° C. for 5 hours. Filter, wash with deionized water and ethanol until neutral, and then dry at 50°C to obtain residue I. The resulting residue I was added to 5% aqueous sodium hydroxide solution and reacted at 100°C for 3 hours, filtered and washed with deionized water and ethanol to neutrality, and dried at 50°C to obtain residue II.

[0041] The obtained residue II was suspended in 2 mol / L dilute hydrochloric acid, and hydrolyzed at room temperature for 2 hours to obtain a degraded cellulose sample. Its viscosity average molecular weight ranges from 12×10 4 -38×10 4 Between g / mol.

[0042] Add the obtained cellulose to the lithium hydroxide / urea (or thiourea) complex aqueous solution, stir for 30 minutes, put it in a refr...

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Abstract

The invention relates to a method for preparing cellulose water-based solution by straws, which consists of three parts: 1) the separation of the cellulose in the straws; 2) cellulose purification and molecular weight adjustment; 3) the dissolution of purified cellulose in aqueous medium. The separation process of the cellulose adopts the method of separating hemicellulose first and then removing lignin; the cellulose purification respectively adopts the method of acid or alkali treatment, and the molecular weight adjustment is finished by hydrolysis; the obtained cellulose is dissolved in alkaline aqueous solution through a pre-cooling method; and uniform and transparent cellulose solution is finally obtained. The method of the invention can realize the process of directly preparing cellulose aqueous solution by straw biomass; the obtained cellulose solution can be widely applied to cellulosic spinning, and the preparation and chemical derivatization reaction of regeneration membrane and resin.

Description

technical field [0001] The invention relates to chemical separation technology, in particular to a new method for separating cellulose from straw and dissolving it with a water-based solvent to obtain an aqueous solution of cellulose. Background technique [0002] Biomass has been attracting much attention as an alternative resource, and its potential applications include synthesis of renewable energy and chemicals. Cellulose, the main component of biomass and the most abundant biopolymer in the biosphere, is also a valuable potential raw material for the preparation of different kinds of new polymers and materials. At present, the preparation of cellulose mainly starts from wood resources, usually involving pulping process (US Patent 0145351 A1, 2005). Agricultural waste, such as non-wood biomass, is rarely used as raw material to produce cellulose. [0003] Separation of cellulose from straw biomass is also generally similar to the pulping process, which mainly includes ...

Claims

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Application Information

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IPC IPC(8): C08J3/03C08L1/02C08B1/00D21C5/00
Inventor 闫立峰王媛媛
Owner UNIV OF SCI & TECH OF CHINA
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