Process for making an ultra stable cementitious construction material
View Patent ↗A process to make a cementitious material includes blending 29 wt % to 40 wt % of a magnesium oxide dry powder containing 80 wt % to 98 wt % of magnesium oxide based on a final total weight of the cementitious material with 14 wt % to 18 wt % of a magnesium chloride dissolved in water and reacting to form a liquid suspension, mixing from 2 to 10 minutes, adding a phosphorus-containing material, and allowing the liquid suspension to react into an amorphous phase cementitious material. A portion of the amorphous phase cementitious material grows a plurality of crystals. The plurality of crystals is encapsulated by the amorphous phase cementitious material forming a nano-molecular veneer.
1. A process of making a cementitious material comprising:
(i) blending
a) 29 wt. % to 40 wt. %, based on the final total weight of the cementitious material, of a magnesium oxide dry powder containing 80 wt. % to 98 wt. % of magnesium oxide, the magnesium oxide powder having a surface area of from 5 m 2 /g to 50 m 2 /g and an average particle size of from about 0.3 μm to about 90 μm, and wherein more than about 90 wt. % of the particles of the magnesium oxide powder have a particle size of less than or equal to about 40 μm, with
b) 14 wt. % to 18 wt. %, based on the final total weight of the cementitious material, of an aqueous solution of magnesium chloride, the aqueous solution of magnesium chloride comprising 20 wt. % to 30 wt. % of magnesium chloride,
and reacting the magnesium oxide and the magnesium chloride to form a liquid suspension;
(ii) mixing the liquid suspension for from 2 minutes to 10 minutes;
(iii) adding 0.1 wt. % to 10 wt. %, based on the final total weight of the cementitious material, of a stabilizing material to the mixed liquid suspension, wherein the stabilizing material is:
1) an aqueous solution comprising 55 wt. % to 65 wt. % of phosphorous acid (H 3 PO 3 ); or
2) an aqueous solution comprising 80 wt. % to 90 wt. % of phosphoric acid (H 3 PO 4 );
(iv) allowing the liquid suspension with the stabilizing material to react for from 1 minute to 4 minutes to form an amorphous phase cementitious material;
wherein a portion of the amorphous phase cementitious material grows a plurality of crystals, each crystal having a molecular weight of from 280 to 709 and being encapsulated by the amorphous phase cementitious material;
wherein a majority of the stabilizing material is consumed during curing into a nano-molecular veneer over the crystals while increasing the surface area of the plurality of crystals by 2% to 49%; and
wherein the nano-molecular veneer is insoluble in water and protects the plurality of crystals from degradation in water at temperatures of from 20° C. to 60° C. for from 24 hours to 56 days.
2. The process of claim 1 , further comprising blending 35 wt. % to 79.9 wt. %, based on the final total weight of the cementitious material, of the formed amorphous phase cementitious material with 0.1 wt. % to 30 wt. %, based on the final total weight of the cementitious material, of an aggregate comprising particles having a diameter from 1 nm to 10 nm, wherein the aggregate comprises at least one selected from the group consisting of wood, perlite, styrene-based foam beads, calcium carbonate powder, and glass particulates.
3. The process of claim 1 , further comprising pouring the amorphous phase cementitious material over 0.1 wt. % to 2 wt. %, based on the final total weight of the cementitious material, of a reinforcing material that cures into the cementitious material, the reinforcing material comprising a non-woven or woven silica-containing mat or a non-woven or woven hydrocarbon-containing mat.
4. The process of claim 1 , further comprising blending the amorphous phase cementitious material with 0.1 wt. % to 15 wt. %, based on the final total weight of the cementitious material, of biomass and mixing from 3 to 10 minutes.
5. The process of claim 4 , wherein the biomass is selected from the group consisting of rice husks, corn husks, and dung.
6. The process of claim 1 , further comprising adding to the amorphous phase cementitious material 0.1 wt. % to 10 wt. %, based on the final total weight of the cementitious material, of at least one surfactant that is effective to decrease the porosity of the aggregate and to prevent the amorphous phase cementitious material from entering pores of the aggregate.
7. The process of claim 6 , wherein the surfactant is a detergent.
8. The process of claim 2 , further comprising adding to the amorphous phase cementitious material 0.1 wt. % to 5 wt. %, based on the final total weight of the cementitious material, of a redispersible powder polymer and mixing from 3 to 10 minutes.
9. The process of claim 8 , wherein the redispersible powder polymer is selected from the group consisting of a silicone, a polyurethane, a polyurethane dispersion, a polymer of an alkyl carboxylic acid vinyl ester monomer, a polymer of a branched or unbranched alcohol ester of (meth)acrylic acid monomer, a polymer of a vinyl aromatic monomer, a polyolefin, a polydiene, a polyvinyl halide, and a copolymer of vinyl acetate and ethylene.
10. The process of claim 8 , further comprising adding to the amorphous phase cementitious material 0.1 wt. % to 5 wt. %, based on the final total weight of the cementitious material, of an acrylic or a styrene-butadiene rubber while the redispersible powder polymer is added.
11. The process of claim 1 , further comprising adding to the amorphous phase cementitious material 0.1 wt. % to 15 wt. %, based on the final total weight of the cementitious material, of at least one reinforcing material selected from the group consisting of chopped silica-containing fibers, hemp-containing fibers, nano-molecular carbon fiber strands, chopped carbon fibers, and chopped hydrocarbon fibers.