Redispersible polymer viscose powder for cement blending and production technique thereof

Abstract

The invention belongs to a modifying additive of a cement material, particularly relates to a redispersible polymer viscose powder for cement blending and a production technique thereof. The viscose powder is prepared by carrying out polymerization reaction on the following raw materials in percentage by weight: 10-35% of vinyl acetate, 10-40% of styrene, 20-50% of methyl acrylate, 0.5-3% of sodium hydroxide, 5-10% of polyvinyl alcohol, 0.2-1% of potassium sulfate and 8-15% of talcum powder. The viscose powder provided by the invention enhances the redispersibility after adding water, can ensure the water resistance and adhesive strength after film formation, and still has the properties of the originally synthesized polymer.

Description

technical field

[0001] The invention belongs to a modified additive for cement materials, and in particular relates to a redispersible polymer viscose powder for mixing with cement and a production process. Background technique

[0002] The application of polymer latex to cement materials not only significantly improves the flexural strength of cement materials, but also significantly improves the fluidity and post-hardening properties of freshly mixed cement materials due to the plasticization and air-entraining effects of emulsifiers in polymer latex. The freeze-thaw resistance of cement materials, polymer latex forms a network structure with cement hydrate after film formation, inhibits the pore structure of cement materials, and significantly reduces the permeability and air permeability of cement materials.

[0003] Redispersible polymer powder refers to the polymer latex obtained by emulsion polymerization, the polymer powder obtained by drying or other means, when mix...

Examples

Embodiment 1

[0016] 1) Mix 15% vinyl acetate, 25% styrene, and 40% methyl acrylate to obtain a mixed monomer;

[0017] 2) Dissolve 7% polyvinyl alcohol and 2.5% sodium hydroxide in water to make an aqueous solution, raise the temperature to 80°C, add mixed monomers and 0.5% potassium sulfate into it, continue to raise the temperature to 95°C, react for 1 hour, and obtain after cooling polymer emulsion;

[0018] 3) Dry the emulsion obtained in step 2) by spraying method, and add 10% talcum powder when spraying to obtain viscose powder.

[0019] When used, the amount of polymer viscose powder accounts for 2% of the quality of cement mortar.

Embodiment 2

[0021] 1) Mix 35% vinyl acetate, 11.9% styrene, and 30% methyl acrylate to obtain a mixed monomer;

[0022] 2) Dissolve 9% polyvinyl alcohol and 0.8% sodium hydroxide in water to make an aqueous solution, heat up to 90°C, add mixed monomer and potassium sulfate 0.3% into it, continue to heat up to 100°C, react for 1.5h, and cool Obtain polymer emulsion;

[0023] 3) Dry the emulsion obtained in step 2) by spraying method, and add 14% talcum powder when spraying to obtain viscose powder.

[0024] When used, the amount of polymer viscose powder accounts for 3% of the quality of cement mortar.

Embodiment 3

[0026] 1) Mix 25% vinyl acetate, 39.7% styrene, and 20% methyl acrylate to obtain mixed monomers;

[0027] 2) Dissolve 5% polyvinyl alcohol and 1.5% sodium hydroxide in water to make an aqueous solution, raise the temperature to 70°C, add mixed monomers and 0.8% potassium sulfate to it, continue to heat up to 90°C, react for 2 hours, and obtain after cooling polymer emulsion;

[0028] 3) Dry the emulsion obtained in step 2) by spraying, and add 8% talcum powder when spraying to obtain viscose powder.

[0029] When used, the amount of polymer viscose powder accounts for 1.5% of the mass of cement mortar.

technical field

[0001] The invention belongs to a modified additive for cement materials, and in particular relates to a redispersible polymer viscose powder for mixing with cement and a production process. Background technique

[0002] The application of polymer latex to cement materials not only significantly improves the flexural strength of cement materials, but also significantly improves the fluidity and post-hardening properties of freshly mixed cement materials due to the plasticization and air-entraining effects of emulsifiers in polymer latex. The freeze-thaw resistance of cement materials, polymer latex forms a network structure with cement hydrate after film formation, inhibits the pore structure of cement materials, and significantly reduces the permeability and air permeability of cement materials.

[0003] Redispersible polymer powder refers to the polymer latex obtained by emulsion polymerization, the polymer powder obtained by drying or other means, when mix...

Examples

Embodiment 1

[0016] 1) Mix 15% vinyl acetate, 25% styrene, and 40% methyl acrylate to obtain a mixed monomer;

[0017] 2) Dissolve 7% polyvinyl alcohol and 2.5% sodium hydroxide in water to make an aqueous solution, raise the temperature to 80°C, add mixed monomers and 0.5% potassium sulfate into it, continue to raise the temperature to 95°C, react for 1 hour, and obtain after cooling polymer emulsion;

[0018] 3) Dry the emulsion obtained in step 2) by spraying method, and add 10% talcum powder when spraying to obtain viscose powder.

[0019] When used, the amount of polymer viscose powder accounts for 2% of the quality of cement mortar.

Embodiment 2

[0021] 1) Mix 35% vinyl acetate, 11.9% styrene, and 30% methyl acrylate to obtain a mixed monomer;

[0022] 2) Dissolve 9% polyvinyl alcohol and 0.8% sodium hydroxide in water to make an aqueous solution, heat up to 90°C, add mixed monomer and potassium sulfate 0.3% into it, continue to heat up to 100°C, react for 1.5h, and cool Obtain polymer emulsion;

[0023] 3) Dry the emulsion obtained in step 2) by spraying method, and add 14% talcum powder when spraying to obtain viscose powder.

[0024] When used, the amount of polymer viscose powder accounts for 3% of the quality of cement mortar.

Embodiment 3

[0026] 1) Mix 25% vinyl acetate, 39.7% styrene, and 20% methyl acrylate to obtain mixed monomers;

[0027] 2) Dissolve 5% polyvinyl alcohol and 1.5% sodium hydroxide in water to make an aqueous solution, raise the temperature to 70°C, add mixed monomers and 0.8% potassium sulfate to it, continue to heat up to 90°C, react for 2 hours, and obtain after cooling polymer emulsion;

[0028] 3) Dry the emulsion obtained in step 2) by spraying, and add 8% talcum powder when spraying to obtain viscose powder.

[0029] When used, the amount of polymer viscose powder accounts for 1.5% of the mass of cement mortar.