Method for preparing dithiocarbamate-based modified porous starch

A technology of dithiocarbamic acid and porous starch, which is applied in the field of modified starch to achieve strong chelation, improved removal rate, and less dosage

Inactive Publication Date: 2010-06-30
TONGJI UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there are fewer reports on modifying porous starch, which are limited to esterified porous starch, such as the porous modified starch (seeing Chinese patent CN 101289684A) of Xu Zhong's phosphorus oxychloride as a cross-linking agent, and the porous starch is dithioated Urethane modification an

Method used

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  • Method for preparing dithiocarbamate-based modified porous starch
  • Method for preparing dithiocarbamate-based modified porous starch

Examples

Experimental program
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Effect test

Embodiment 1

[0033] First, 30 g of commercially available potato starch was used as a raw material and dissolved in 200 mL of a buffer solution with a pH of 5 to obtain a starch slurry with a concentration of 15% by mass. The buffer solution is obtained by measuring commercially available analytically pure citric acid: disodium hydrogen phosphate = 1:2 mass ratio, then adding water and stirring until uniform. Then add the compound enzyme that is made up of the glucoamylase of 0.15g and 0.75g alpha-amylase in the starch slurry, the addition of compound enzyme is 3.0% of starch weight, then react at constant temperature under 45 ℃ of water bath shaking conditions for 8h, then from water bath Take it out, add 5mL of sodium hydroxide solution with a mass percentage concentration of 4%, stop the enzymatic hydrolysis reaction, and then filter and separate the solid and supernatant, wash the solid with distilled water until the pH value is neutral, and finally at 45 ° C Dry under vacuum for 12 ho...

Embodiment 2

[0040] 30g potato starch was dissolved in the same 200mL pH as in Example 1 in the buffer solution of sodium citrate-disodium hydrogen phosphate of 5 to obtain a starch slurry with a concentration of 15% by mass. Add a compound enzyme consisting of 0.25 g of glucoamylase and 0.50 g of α-amylase to the starch slurry. The amount of the compound enzyme added is 2.5% of the weight of the starch, followed by a constant temperature reaction at 60 ° C and a water bath for 18 hours, then taken out and removed. Add 5mL of sodium hydroxide solution with a concentration of 4% by mass to terminate the enzymatic hydrolysis reaction, then filter and separate the solid and supernatant, wash the solid with distilled water until the pH value is neutral, and finally dry it in vacuum at 45°C After 12 hours, the white powder obtained is porous starch, and the water absorption rate of the porous starch is ≥1.80g / g.

[0041] Add 20mL of dilute lye and 2mL of epichlorohydrin to 5g of porous starch, ...

Embodiment 3

[0046] Cornstarch was used as raw material, diethylenetriamine was used as amination agent, and the rest of the formula was the same as in Example 1 to obtain dithiodiethylenetriamine formic acid-based modified porous cornstarch.

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Abstract

The invention relates to a method for preparing dithiocarbamate-based modified porous starch. The method comprises the steps that: using starch as the raw material; carrying out enzymolysis on the starch for 1 to 26 hours under the condition that the pH is between 4 and 6 and the temperature is between 30 and 60 DEG C by a complex enzyme consisting of a saccharifying enzyme and an alpha-amylase; drying the obtained product to prepare porous starch; and after carrying out crosslinking, etherification and aminating modification on the porous starch, grafting the product with carbon disulfide under the alkaling conndition to obtain the dithiocarbamate-based modified porous starch. Compared with the conventional porous starch, the dithiocarbamate-based modified porous starch of the invention has strong absorption characteristic and high adsorptive selectivity. When the adsorption effect is reduced, the dithiocarbamate-based modified porous starch is taken out and immersed in 2mol.L-1 of HNO3 solution to carry out desorption, the desorption ratio is over 90 percent, and the absorption effect is not reduced by repeated desorption. The invention has commendable economic and social benefits, and can be used for treatment of heavy metal ions in waste water in galvanization, battery and mining industries and the like.

Description

technical field [0001] The invention discloses a preparation method of dithiocarbamic acid-based modified porous starch, which relates to a preparation process of porous starch used for wastewater treatment. It belongs to the technical field of modified starch. technical background [0002] Porous starch, also known as microporous starch, refers to the enzyme with raw amylase activity acting on raw starch granules below the starch gelatinization temperature to form a porous honeycomb product. Porous starch is a new type of starch Modified starch, its research and application are gradually receiving people's attention. Compared with native starch, porous starch has the following characteristics: (1) larger specific pore volume; (2) larger specific surface area; (3) low bulk density and particle density; (4) good water and oil absorption capacity (5) Good mechanical strength in dry state; (6) Dispersed in water and other solvents can maintain obvious structural integrity; (7...

Claims

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Application Information

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IPC IPC(8): C08B31/00C08B31/12C02F1/28C02F1/62C02F101/20
Inventor 王作华相波江志平曲乐李义久李菁
Owner TONGJI UNIV
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