Preparation method for super absorbent resin

Abstract

The invention discloses a preparation method for super absorbent resin. In the method, acrylic acid is used as a raw material; an alkaline aqueous liquid is used as a neutralizer to neutralize the acrylic acid; then a cross-linking agent and an initiator are added for implementing polymerization; after the polymerization is finished, resin grains are obtained in sequence through pelleting, drying and crashing; surface treatment is implemented on the resin grains to obtain the super absorbent resin with the advantages of low monomer residue, high pressure resistance and absorbency, fast absorbent speed, excellent condensation resistance and good flowability. The preparation method has fast rate of polymerization and is very stable. The polymer gel grains obtained through reaction can be independently dispersed and can not be mutually stuck and caked. The preparation method has simple technology, high efficiency and high energy utilization.

Description

technical field [0001] The invention belongs to the field of macromolecular materials, and relates to a method for manufacturing a superabsorbent resin, in particular to a method for preparing a polyacrylic acid type superabsorbent resin. The product prepared by the invention has low residual monomer content, high pressurized water absorption rate, fast water absorption rate, anti-coagulation, good fluidity, and does not contain any pollutants, and is especially suitable for daily sanitary materials. Background technique [0002] Superabsorbent resin is a new type of functional polymer material with a three-dimensional network structure, which can absorb hundreds to thousands of times its own weight in deionized water, and can absorb tens to hundreds of times its own weight in 0.9% NaCl aqueous solution (physiological brine). Compared with general traditional water-absorbing materials, superabsorbent resin has a strong water-retaining capacity in addition to high water-abso...

AI Technical Summary

Problems solved by technology

[0004] The aqueous solution polymerization method to produce cross-linked polyacrylic acid superabsorbent resin does not use organic solvents, is safe and environmentally friendly, and is currently the method adopted by most manufacturers. However, this aqueous solution polymerization reaction system has a high viscosity, and the polymerization heat cannot be dissipated in time, making the system temperature It is difficult to control, and the temperature is too high, prone to implosion, which will reduce the product performance indicators (including water absorption, residual monomer, etc.)

When implosion occurs, the temperature at the center of the reaction system is too high, and molecular chains with a relatively uniform molecular weight distribution cannot be formed. The gel strength decreases, the colloid has strong adhesion, and the content of soluble matter increases, resulting in a decrease in the overall performance of the product. On the other hand, it will also affect Subsequent processing

The use of low-temperature initiation polymerization can effectively avoid the occurrence of implosion polymerization, and products with excellent performance can be obtained, but low-temperature initiation will cause the extension of reaction time, which is not conducive to improving industrial production efficiency, so there is a problem that it is difficult to balance quality and efficiency.

[0005] Ordinary water-absorbing resin (obtained by drying and granulating the hydrogel obtained from the polymerization reaction) is directly used in sanitary products. After absorbing liquid, the gel strength is low, and the low water absorption rate under pressure makes it easy to leak body fluids, and it is prone to coagulation after absorbing water. Glue blocking effect reduces water absorption rate

Generally, increasing the density of cross-linking points can increase the gel strength but the water absorption will decrease, thus affecting the application performance

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