Method for synchronously preparing high water absorption rate polymer through integrated polymerization, pore formation and pelleting

Abstract

The invention discloses a method for synchronously preparing a high water absorption rate polymer through integrated polymerization, pore formation and pelleting. The method comprises the following steps: by taking olefine acid salts, olefine acid monomers and a grafting polymer as polymerization monomer mixtures, an initiation system as a water-soluble oxidant and a natural product reducing agent, carrying out compounding so as to obtain the polymer, and putting the polymer into a cooling device to reduce the temperature of the system, wherein the system has no chemical change at the moment;in preparation, putting a suspension medium and a dispersant into the reaction system, reducing the temperature of the reaction system to minus 15 DEG C to minus 20 DEG C to initialize completion of apolymerization reaction, carrying out a constant temperature reaction to complete polymerization, depositing generated spherical polymer granules to the bottom, separating so as to obtain polymer granules, melting at the normal temperature, finally, dehydrating and drying by using a dehydration agent, thereby obtaining a product. By adopting the method for synchronously preparing the high water absorption rate polymer through integrated polymerization, pore formation and pelleting, synchronous completion of polymerization reactions, pore forming and pelletizing, later pore formation and preprocessing can be avoided, and the liquid absorption rate of a liquid can be greatly increased because of uniform and continuous pores in the surface and inside the prepared super high water absorptionrate polymer.

Description

technical field [0001] The invention relates to the technical field of functional polymer materials, in particular to a method for synchronously preparing polymers with high water absorption rates through polymerization, pore formation and granulation. Background technique [0002] Superabsorbent polymer is a new type of polymer with strong hydrophilic groups with a three-dimensional network structure that has developed rapidly in recent years. It can quickly absorb a large amount of water and swell into a gel-like resin with high water absorption. and water retention. Superabsorbent polymers have been widely used in many fields such as medical and health care, industry, agriculture, forestry and daily life, among which medical and sanitary products such as urinary incontinence mattresses, infant diapers and women's sanitary napkins account for more than 70% of the total market . [0003] Traditional superabsorbent polymers are polymer gel blocks, and their microstructure ...

AI Technical Summary

Problems solved by technology

The preparation process of this method is long, and the pore-forming time exceeds 24 hours. The ice needs to be sublimated in a negative pressure environment for freezing, and the system pressure is under 5-20kPa for a long time. Pores are often formed on the surface first, and finally the interior of the gel forms pores, and the prepared porous water-absorbing polymer has uneven pores.

(2) Foam dispersion method: the necessary condition is that the system should have a foaming agent, or a polymerization system that generates a large amount of gas such as salt (such as sodium carbonate, sodium bicarbonate) and acid. The biggest bottleneck of this polymerization technology is the control of the reaction system. The liquid film in the foam gap generated instantaneously is used as the polymerization site, and the completed pores exist in the form of a gel in a dispersed state without continuity. In addition, there is a complicated relationship between the removal of the polymerization heat and the influence on the size of the foam. Therefore, the foam of the finished product The surface gel block also needs to remove the non-pore-forming area, and a large amount of solvent is needed to remove impurities such as foaming agent, and the subsequent treatment process is complicated

(3) Self-propagating wave polymerization technology: the key point is to use the reaction heat generated in the reaction area to trigger the unreacted area, and at the same time, the reaction heat in the newly reacted area promotes the vaporization of the solvent in the fully reacted gel to thermally form pores, so the polymerization Heat control is the difficulty of the whole polymerization. The overheating of the reaction will lead to uneven pores. The polymerization temperature is 80-110 ° C. If the temperature is too high, the phenomenon of implosion will occur; if the polymerization temperature is low, such as using persulfate as the initiation system When the temperature is lower than 60 °C, the phenomenon of "polymerization quenching" will suddenly appear. Therefore, this technology is only in the laboratory research stage at present, and it is difficult to quickly and effectively prepare porous water-absorbing polymers on a large scale.

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