CN104140492A - Method for preparing superabsorbent polymer (SAP) from acrylamide (AM) and maleic acid (MA) - Google Patents

Abstract

The invention relates to a method for preparing a superabsorbent polymer (SAP) from acrylamide (AM) and maleic acid (MA) and discloses a method for preparing the SAP. The method is characterized by comprising the steps of dissolving and mixing AM, MA and a crosslinking agent, adding an initiator for polymerization and then carrying out dewatering and drying, thus preparing the product, namely the superabsorbent polymer. The method has the beneficial effects that the whole synthesis condition is simple; the cost is low; industrial production is safe and is easy to control; the product has stable quality and high water absorbency and is environment-friendly and pollution-free.

Description

Preparation method of acrylamide and maleic acid water-absorbing resin

technical field

The invention relates to a method for preparing water-absorbing resin, in particular to a method for preparing water-absorbing resin by using acrylamide (AM) and maleic acid (MA) as raw materials.

Background technique

Water-absorbent resin (SAP) has a high water absorption function of absorbing water hundreds to thousands of times heavier than itself, and has excellent water retention performance. Once it absorbs water and swells into a hydrogel, it is difficult to separate the water even if it is pressurized. Water-absorbent resin is a functional polymer material characterized by a large number of hydrophilic groups, and is a widely used industrial product. The existing superabsorbent resin method is mainly prepared from starch, carboxymethyl cellulose, acrylic acid, etc. by polymerization. The current preparation of water-absorbent resin has a single raw material and is relatively expensive. At the same time, although the existing water-absorbing resin has strong water-absorbing energy as a whole, it has poor salt resistance and temperature resistance; the absorption rate of physiological saline is only dozens of times, and the water-absorbing mechanism needs further breakthroughs.

Contents of the invention

The specific technical problem to be solved in the present invention is how to increase the application ratio of maleic acid in the preparation of acrylamide water-absorbent resins, and select a crosslinking agent corresponding to the water-absorbent resins, so as to greatly reduce the preparation cost and further increase the production cost. Its water absorption rate, its purpose is to provide a cheap and easy-to-obtain preparation method of water-absorbent resin, to be widely used in industrial and agricultural production.

The preparation method of acrylamide provided by the present invention, maleic acid water-absorbing resin:

(1) Prepare maleic acid solution with distilled water;

(2) Adjust the maleic acid solution with 25% NaOH solution to make the neutralization degree reach 80%;

(3) Mix acrylamide and maleic acid monomers at a mass ratio of 4:1, add 0.1% mass fraction of cross-linking agent N,N'-methylbisacrylamide solution, heat to 45~55°C, and then Stir at a speed less than or equal to 100rpm for 5 to 15 minutes to obtain a synthetic solution;

(4) The initiator ammonium persulfate-sodium bisulfite was added to the synthesis solution at a mass ratio of 0.2%, protected by nitrogen gas, reacted for 4~6 hours, and then cooled to room temperature to obtain a hydrogel;

(5) Dry the hydrogel to obtain a water-absorbent resin;

(6) Pulverize the water-absorbent resin to obtain a powdery water-absorbent resin.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a process flow chart of the preparation method of acrylamide and maleic acid water-absorbing resin.

The specific embodiment The present invention is further described and illustrated by specific embodiments below:

Weigh 2g of maleic acid, prepare a solution, add 25% NaOH solution to adjust the neutralization degree (N) of maleic acid to 80%; accurately weigh 8g of acrylamide and place it in a 250mL three-necked flask, add the above-mentioned maleic acid Add acid solution and stir well to make it evenly dispersed; add quantitative distilled water to make w(MA+AM)=20% (based on the mass of the system); then add 0.1% of crosslinking agent N,N'-methylbis Acrylamide solution, heated to 50 ° C, dropwise added 0.2% mass fraction of initiator ammonium persulfate-sodium bisulfite solution, continued to stir until uniformly mixed; nitrogen gas was introduced to maintain a constant temperature of 50 ° C for reaction. React for 5 hours to obtain a colorless and transparent colloid; place the colloid in a vacuum oven at 65°C to dry to constant weight, and pulverize the dried product to obtain a crude product of superabsorbent resin; soak the crude product in deionized water at 70°C, Stir and wash 3 times to remove uncrosslinked homopolymer and unreacted monomer, filter, dry and pulverize to obtain purified water-absorbent resin P (MA/AM). The water absorption rate in pure water is 220g/g.

Claims (3)

1. the preparation method of acrylamide, toxilic acid water-absorbing resin, is characterized in that: prepare maleic acid solution with distilled water; Maleic acid solution is regulated with 25% NaOH solution, and making its degree of neutralization is 80%; Acrylamide is joined in above-mentioned solution with certain mass ratio, and acrylamide and toxilic acid mass ratio are 4 ︰ 1; Dripping massfraction is 0.1% linking agent N again, N ＇-methyl bisacrylamide; Be heated to 45 ~ 55 DEG C, then after 5 ~ 15 minutes, obtain synthetic liquid with the speed stirring that is less than or equal to 100rpm; Initiator ammonium persulfate-sodium sulfite solution is joined in synthetic liquid with massfraction 0.2% ratio, and logical hydrogen shield, after reaction 4 ~ 6h, is then cooled to normal temperature, obtains hydrogel; After being dried, hydrogel obtains water-absorbing resin; Water-absorbing resin is pulverized, obtained Powdered water-absorbing resin.

2. preparation method as claimed in claim 1, is characterized in that, described in it, acrylamide and toxilic acid mass ratio are 4 ︰ 1.

3. preparation method as claimed in claim 1, is characterized in that, linking agent N described in it, and N ＇-methyl bisacrylamide massfraction is 0.1%.