Preparation method of sodium polyacrylate aqueous solution with high solid content and narrow molecular weight distribution

A technology of narrow molecular weight distribution and sodium polyacrylate, which is applied in the field of preparation of high solid content and narrow distribution sodium polyacrylate, can solve the problems of environmental protection, time-consuming and energy-consuming, etc., and achieves the effects of low production conditions, reduced pollution and simple operation.

Inactive Publication Date: 2013-01-09
四川花语精细化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Sodium tripolyphosphate is the most ideal detergent builder in synthetic detergents in terms of cost performance, but sodium tripolyphosphate will cause eutrophication of water, leading to environmental problems
[0006] In summary, in the preparation process of sodium polyacrylate solution, how to overcome the time-consuming and energy-consuming problems of producing sodium polyacrylate solution by common production methods, and obtain sodium polyacrylate solution with small molecular weight, uniform molecular weight distribution and high solid content , has become a technical problem that needs to be solved urgently but cannot be solved in this industry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Add 900g deionized water and 15.8g sodium hypophosphite into the reactor, stir to prepare sodium hypophosphite solution, heat to 85°C, then dropwise add 1440g acrylic acid monomer, 228.8g ammonium persulfate aqueous solution (from 28.8 g ammonium persulfate and 200g water), 263.4g sodium hypophosphite aqueous solution (composed of 63.4g sodium hypophosphite and 200g water), the dropping time is 0.5h. °C; then lower the temperature to below 50 °C, and slowly add 1500 g of NaOH aqueous solution with a mass concentration of 50% to neutralize;

[0030] The obtained sodium polyacrylate has a solid content of 46.1%, a weight average molecular weight of 6500, and a molecular weight distribution coefficient of 2.1.

Embodiment 2

[0032] Add 900g deionized water and 28.8g sodium hypophosphite to the reactor, stir to prepare sodium hypophosphite solution, heat to 85°C, then dropwise add 1440g acrylic acid monomer, 207.2g ammonium persulfate aqueous solution (from 7.2 g ammonium persulfate and 200g water), 315.2g sodium hypophosphite aqueous solution (composed of 115.2g sodium hypophosphite and 200g water), the dropwise addition time is 5h, after the dropwise addition, keep warm for 0.5h, and the temperature is controlled at 60°C; Then lower the temperature to below 50°C, slowly add 1500g of NaOH aqueous solution with a mass concentration of 50% to neutralize;

[0033] The obtained sodium polyacrylate has a solid content of 47.2%, a weight average molecular weight of 7300, and a molecular weight distribution coefficient of 2.4.

Embodiment 3

[0035]Add 900g of deionized water and 15.8g of sodium hypophosphite into the reactor, stir, and heat to 60°C, then dropwise add 1440g of acrylic acid monomer and 228.8g of ammonium persulfate aqueous solution (from 28.8g of ammonium persulfate and 200g of water), 263.4g sodium hypophosphite aqueous solution (composed of 63.4g sodium hypophosphite and 200g water), the dropwise addition time is 2h, after the dropwise addition, keep warm for 2h, the temperature is controlled at 84-86°C, and then cooled to 50°C Below ℃, slowly add 1500g of 50% NaOH aqueous solution to neutralize to neutral. The obtained sodium polyacrylate has a solid content of 45.6%, a weight average molecular weight of 7600, and a molecular weight distribution coefficient of 1.9.

[0036]

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Abstract

The invention discloses a preparation method of a sodium polyacrylate aqueous solution with high solid content and narrow molecular weight distribution. The method comprises the following steps: solution preparation: deionized water and sodium hypophosphite are added into a reactor and continuously stirred for dissolving to prepare a solution of sodium hypophosphite, and the solution is heated to 60-110 DEG C at the same time; polymerization: acrylic acid monomer, an initiator and sodium hypophosphite are sequentially dripped into the solution prepared in the step of the solution preparation for 0.5-5h, constant-temperature reaction is carried out for 0.5-5h after the dripping to obtain a mixture, an alkali is added to neutralize the mixture to neutrality after the reaction is completed. The method uses sodium hypophosphite as the chain transfer agent to prepare the aqueous solution of sodium polyacrylate, wherein the solid content of the aqueous solution is greater than or equal to 45.0%, the weight molecular weight of the aqueous solution is 1000-10000, and the molecular weight distribution of the aqueous solution is 1.7-2.5. The aqueous solution of sodium polyacrylate has higher chelating ability, dispersion force and antiredeposition ability, and can partly or completely replace sodium tripolyphosphate to be used in washing products to reduce pollutions of detergents to the environment.

Description

technical field [0001] The invention relates to a production process of sodium polyacrylate aqueous solution, in particular to a preparation method of sodium polyacrylate with high solid content and narrow distribution. Background technique [0002] Sodium polyacrylate is a water-soluble polymer. The solid product is white (or light yellow) block or powder, and the liquid product is colorless (or light yellow) viscous liquid. Dissolved in cold water, warm water, glycerin, propylene glycol and other media, it is stable to temperature changes, has the effect of fixing metal ions, and can prevent the negative effects of metal ions on products. It is a surfactant with many special properties. [0003] Sodium polyacrylate has been extensively studied in recent years. The molecular weight of sodium polyacrylate can range from hundreds to tens of millions, and sodium polyacrylates with different molecular weights have different uses. The low molecular weight is about 1000-10000, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F120/06C08F2/10C08F2/38
Inventor 张涌余照权
Owner 四川花语精细化工有限公司
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