Homogeneous chemical modification of hemicellulose of stalks

A technology of hemicellulose and chemical modification, applied in the new process field, can solve the problems of pre-activation treatment of hemicellulose, low yield of modification reaction, limited industrial application, etc., to improve hydrophobicity, reduce production cost, reduce The effect of pollution

Inactive Publication Date: 2003-06-18
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, most of the chemically modified hemicelluloses are currently carried out in heterogeneous media without pre-activation treatment of the hemicelluloses, so the yield of the modification reaction is low and the cost is high, which limits the industrial application.
So far, there is no technology to pre-activate hemicellulose and homogeneously chemically modify straw hemicellulose

Method used

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  • Homogeneous chemical modification of hemicellulose of stalks
  • Homogeneous chemical modification of hemicellulose of stalks
  • Homogeneous chemical modification of hemicellulose of stalks

Examples

Experimental program
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Effect test

Embodiment 1

[0019] In the first step, 50 grams of pulverized stalks are placed in a 3000ml glass reactor, and 950ml of 2% H 2 o 2 Aqueous solution, adjust the pH value of the solution with 20% NaOH aqueous solution to be 12.0, control the reaction temperature to be 40 ℃, react under stirring for 18 hours, filter and wash the residue with distilled water, combine the filtrate, then adjust the acidity to pH= 5.5, Concentrate the filtrate to 500ml under reduced pressure, add 3 times the volume of 95% ethanol to precipitate the soluble hemicellulose, after filtering, wash the obtained hemicellulose fully with 70% ethanol and air dry to obtain 10.8 grams of hemicellulose vegetarian products;

[0020] In the second step, 6.0 grams of purified hemicellulose (equivalent to 0.08 moles of xylose hydroxyl groups in hemicellulose composition) are placed in a 1000ml glass reactor, add 100ml of distilled water, and stir at 80°C for about 5 minutes until the hemicellulose completely dissolved;

[002...

Embodiment 2

[0025] In the first step, 50 grams of pulverized stalks are placed in a 3000ml glass reactor, and 950ml of 2% H 2 o 2 Aqueous solution, adjust the pH value of the solution with 20% NaOH aqueous solution to be 12.3, control the reaction temperature to be 50 ℃, react under stirring for 12 hours, filter and wash the residue with distilled water, combine the filtrate, then adjust the acidity to pH= with 6M HCl solution 5.5. Concentrate the filtrate to 600ml under reduced pressure, add 4 times the volume of 95% ethanol to precipitate the soluble hemicellulose, after filtering, wash the obtained hemicellulose fully with 70% ethanol and air-dry to obtain 14.1 grams of hemicellulose vegetarian products;

[0026] In the second step, 6.0 grams of purified hemicellulose (equivalent to 0.08 moles of xylose hydroxyl groups in hemicellulose composition) are placed in a 1000ml glass reactor, add 100ml of distilled water, and stir at 80°C for about 5 minutes until the hemicellulose complete...

Embodiment 3

[0031] In the first step, 50 grams of pulverized stalks are placed in a 3000ml glass reactor, and 950ml of 2% H 2 o 2 Aqueous solution, adjust the pH value of the solution with 20% NaOH aqueous solution to be 12.5, control the reaction temperature to be 60 ℃, react under stirring for 5 hours, filter and wash the residue with distilled water, combine the filtrate, then adjust the acidity to pH= 6.0, concentrate the filtrate to 800ml under reduced pressure, add 4 times the volume of 95% ethanol to precipitate the soluble hemicellulose, after filtration, fully wash the obtained hemicellulose with 70% ethanol and air dry to obtain 16.6 grams of hemicellulose vegetarian products;

[0032]In the second step, 6.0 grams of purified hemicellulose (equivalent to 0.08 moles of xylose hydroxyl groups in hemicellulose composition) are placed in a 1000ml glass reactor, add 100ml of distilled water, and stir at 70°C for about 10 minutes until the hemicellulose is completely dissolve;

[0...

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Abstract

A homogeneous process for chemically modifying the straw's hemicellulose includes such steps as extracting hemicellulose from straw by H2O2, activating by distilled water, adding acid chloride, reacting in homogeneous medium system (N, N-dimethylformamide / lithium chloride), adding the reacted mixture to alcohol, filtering, washing and baking. Its advantages are less environmental pollution, high speed and output and low cost.

Description

(1) Technical field [0001] The invention relates to the technical field of new technology, in particular to a novel method for homogeneously chemically modifying straw hemicellulose. (2) Background technology [0002] Scientists have studied wood hemicellulose relatively early, but in recent decades, they have mainly focused on the selection of extraction technology and structure determination. As early as 1959, Professor Aspinall of the University of Edinburgh and his research team determined the content and structure of hemicellulose in various woods, but in the following three decades, there was little research on hemicellulose. Until the past ten years, with the sharp reduction of the world's forest area and the increase of wood prices, for the first time, there has been an upsurge in the research and development of crop straws, especially the research on hemicellulose. In my country, straw has always been used as a raw material for papermaking. People have done a lot o...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08B37/14
Inventor 孙润仓孙晓锋
Owner SOUTH CHINA UNIV OF TECH
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