Expansive polymer grouting material for treating high-pressure large-flow-rate karst water inrush and preparation method thereof
A preparation method of an expansive polymer grouting material for treating high-pressure large-flow-rate karst water inrush includes: 1) adding a crosslinking agent to acrylic acid; then adding a polymer water-absorbent resin comonomer and performing a polymerization reaction to obtain a precursor; 2) adding an initiator to the precursor obtained in step 1), heating the mixture, performing a reaction to obtain a hydrogel, and grinding the hydrogel to obtain a primary polymer water-absorbent resin; 3) spraying a surface crosslinking agent onto a surface of the primary polymer water-absorbent resin obtained in step 2), and drying the product; and 4) preparing a suspension from an inorganic water conducting agent, spraying the suspension onto the product obtained in step 3), and performing drying to obtain the expansive polymer grouting material.
1. A preparation method of an expansive polymer grouting material for treating high-pressure large-flow-rate karst water inrush, comprising the following steps:
(1) adding a crosslinking agent to acrylic acid; then adding a polymer water-absorbent resin comonomer and performing a polymerization reaction to obtain a precursor;
(2) adding an initiator to the precursor of step (1), heating the mixture, performing a reaction to obtain a hydrogel, and grinding the hydrogel to obtain a primary polymer water-absorbent resin;
(3) spraying a surface crosslinking agent onto a surface of the primary polymer water-absorbent resin of step (2), and drying the obtained product for later use; and
(4) preparing a suspension from an inorganic water conducting agent, spraying the suspension onto the dried product of step (3), and performing drying to obtain the expansive polymer grouting material;
wherein the polymer water-absorbent resin comonomer comprises polyvinyl alcohol, acrylamide, methacrylamide or acrylonitrile;
the crosslinking agent comprises one or a combination of more of N,N-methylenebisacrylamide, dipentaerythritol hexaacrylate, pentaerythritol tetraester, pentaerythritol triallyl ether, pentaerythritol triacrylate, polyethylene glycol diglycidyl ether, ethoxylated glycerol triacrylate and ethylene glycol dimethacrylate;
the surface crosslinking agent comprises one or a combination of more of water, polylol, glycidyl ether, ethylene carbonate, propylene carbonate and a polyvalent metal compound; and
the inorganic water conducting agent comprises fumed silica, nano titania or activated alumina powder.
2. A preparation method of an expansive polymer grouting material for treating high-pressure large-flow-rate karst water inrush, wherein in the preparation method according to claim 1 , when a precursor is prepared in step (1), firstly, acrylic acid is incompletely neutralized with lye to obtain an incompletely neutralized solution containing acrylic acid, then the incompletely neutralized solution and a crosslinking agent are mixed and subjected to a polymerization reaction with a polymer water-absorbent resin comonomer to obtain the precursor, and the subsequent steps are the same as steps (2)-(4) in the preparation method according to claim 1 .
3. The preparation method according to claim 2 , wherein a degree of neutralization of the incompletely neutralized solution is maintained at 40%-90%.
4. The preparation method according to claim 2 , wherein the lye comprises sodium hydroxide, calcium hydroxide or a mixture of both.
5. The preparation method according to claim 2 , wherein a mass concentration of the lye is 20-50%.
6. The preparation method according to claim 1 , wherein in step (1), a mass concentration of the acrylic acid is 25-45%.
7. The preparation method according to claim 6 , wherein in step (1), the polymer water-absorbent resin comonomer is added in a proportion of 0.5-20% by mass of the acrylic acid in step (1).
8. The preparation method according to claim 6 , wherein in step (1), the crosslinking agent is added in a proportion of 0.5-2% by mass of the acrylic acid in step (1).
9. The preparation method according to claim 6 , wherein in step (2), the initiator is added in a proportion of 0.1-0.7% by mass of the acrylic acid in step (1).
10. The preparation method according to claim 6 , wherein in step (3), the surface crosslinking agent is added in a proportion of 3-6% by mass of the primary polymer water-absorbent resin in step (2).
11. The preparation method according to claim 6 , wherein in step (4), the inorganic water conducting agent is added in a proportion of 0.5-1.5% by mass of the primary polymer water-absorbent resin.
12. The preparation method according to claim 1 , wherein
in step (2), the initiator comprises: an inorganic peroxide initiator, an azo initiator and redox initiators.
13. The preparation method according to claim 12 , wherein the inorganic peroxide initiator comprises potassium persulfate, sodium persulfate and ammonium persulfate;
the azo initiator comprises azobisisobutyronitrile, azobisisoheptonitrile and dimethyl azobisisobutyrate; and
the redox initiators comprise ammonium persulfate/sodium bisulfite, hydrogen peroxide/ferrous sulfate, ammonium persulfate/ferrous sulfate and potassium persulfate/ferrous chloride; wherein the substance before “/” indicates an oxidation initiator, the substance after “/” indicates a reduction initiator, and each couple of redox initiators are used at the same time; and a mass ratio of the oxidation initiator to the reduction initiator is 1:3-8.
14. The preparation method according to claim 1 , wherein
the polylol comprises ethylene glycol, propylene glycol or glycerol; and the polyvalent metal compound comprises silver nitrate and cupric chloride.
15. The preparation method according to claim 1 , wherein in step (2), the heating means: gradually increasing a reaction temperature from 0 to 85° C., and the initiator is a combination of an inorganic peroxide initiator, an azo initiator and redox initiators.
16. The preparation method according to claim 15 , wherein a mass ratio of the inorganic peroxide initiator to the azo initiator to the redox initiators is 1-2:1-2:1-7.
17. The preparation method according to claim 1 , wherein in step (1), the time of the polymerization reaction is 1-1.5 h; and in steps (3) and (4), the drying conditions are: aeration-drying at 100-120° C. for 20-60 min.
18. An expansive polymer grouting material prepared by the method according to claim 1 , wherein the grouting material has a core-shell structure, wherein the primary polymer water-absorbent resin obtained in step (2) is a core, and the surface crosslinking agent and the water conducting agent respectively added in step (3) and step (4) are a shell.
19. An expansive polymer grouting material composition, wherein the composition is composed of an expansive polymer grouting material and a carrying fluid; and the expansive polymer grouting material is the expansive polymer grouting material obtained by the preparation method according to claim 1 .
20. The composition according to claim 19 , wherein the carrying fluid comprises one or both of glycerol and ethanol.
21. The composition according to claim 19 , wherein a mass ratio of the expansive polymer grouting material to the carrying fluid is 1-2:1-5.