Preparation method of cellulose ether with high suspension, strong rheology and bleeding prevention

Abstract

The invention belongs to the technical field of modified synthesis of cellulose ether, and particularly discloses a preparation method of high-suspension, strong-rheology and anti-bleeding cellulose ether. The method comprises the following steps: synthesizing and preparing cellulose ether by a universal process flow; during subsequent synthesis, adding a water-soluble rheological polymerization modification monomer with a proper concentration ratio; and carrying out substitution treatment under the conditions of a proper catalyst and a water bath temperature to finally obtain the modified cellulose ether. According to the invention, the cellulose ether has the advantages of high water-retaining property, low viscosity, high suspension, strong rheology, sedimentation resistance and the like, is used in self-leveling mortar, grouting materials, grouting agents, high-performance concrete and other mortars, can ensure high fluidity and pumpability, avoid the phenomena of sand setting, bleeding, layering, segregation and the like during construction, maintain the cohesive viscosity of pouring self-leveling, grouting materials and concrete and ensure the uniformity and the stability ofhardened mortar, and avoids the quality problem.

Description

technical field

[0001] The invention belongs to the technical field of modification and synthesis of cellulose ether, and in particular relates to a preparation method of cellulose ether with high suspension, strong rheology and anti-bleeding. Background technique

[0002] In mortar and concrete, cellulose ether, as an essential additive, is widely used in mortar and concrete due to its excellent water retention and thickening properties. In mortar and concrete, cellulose ether can not only play a role in water retention The thickening effect can also prevent the mortar from segregating, settling, and bleeding, and improve the construction and workability of the mortar. For products with relatively high fluidity requirements, such as self-leveling, grouting materials, grouting agents, and high-performance concrete, etc., Cellulose ether with low viscosity is used, but self-leveling, grouting material, grouting agent, and high-performance concrete products are often used duri...

Examples

Embodiment 1

[0014] A preparation method of high-suspension, strong rheology, anti-bleeding cellulose ether, comprising the following steps:

[0015] (1) Preparation of cellulose ether with a viscosity of 400-1000mpa.s: impregnate the refined cotton with a 40% NaOH solution for 1 hour, then carry out alkalization treatment at 30°C, then seal the reactor and vacuumize it, and add A certain amount of etherification agent, the etherification agent is one of methyl chloride, propylene oxide, methyl chloride, and ethylene oxide, wherein the mass ratio of cotton fiber to etherification agent is 1:1.5-2.0, and then slowly heat up to React at 40°C for 2 hours, continue to heat up and react at 70°C for 1.5 hours, the prepared cellulose ether is at least one of hydroxypropyl methylcellulose ether or hydroxyethyl methylcellulose ether, the initiator It is at least one of potassium persulfate or sodium persulfate;

[0016] (2) Carry out modification and substitution treatment on the cellulose ether p...

Embodiment 2

[0018] The difference between Example 2 and Example 1 is that: when performing rheology modification treatment, the ratio of each component is roughly 2:1 by mass ratio of cellulose ether to water-soluble rheological polymerization modification monomer, wherein The water-soluble rheological polymerization modified monomer is ethylene oxide monomer and acrylamide monomer mixed at a ratio of 1:1, and the prepared cellulose has a viscosity of 430mpa.s.

Embodiment 3

[0020] The difference between Example 3 and Example 1 is that: when performing rheology modification treatment, the ratio of each component is approximately 3:1 by mass ratio of cellulose ether to water-soluble rheological polymerization modification monomer, wherein The water-soluble rheological polymerization modified monomer is 1:1 mixed substitution of ethylene oxide monomer and acrylamide monomer, and the viscosity of the prepared cellulose is 450mpa.s.

technical field

[0001] The invention belongs to the technical field of modification and synthesis of cellulose ether, and in particular relates to a preparation method of cellulose ether with high suspension, strong rheology and anti-bleeding. Background technique

[0002] In mortar and concrete, cellulose ether, as an essential additive, is widely used in mortar and concrete due to its excellent water retention and thickening properties. In mortar and concrete, cellulose ether can not only play a role in water retention The thickening effect can also prevent the mortar from segregating, settling, and bleeding, and improve the construction and workability of the mortar. For products with relatively high fluidity requirements, such as self-leveling, grouting materials, grouting agents, and high-performance concrete, etc., Cellulose ether with low viscosity is used, but self-leveling, grouting material, grouting agent, and high-performance concrete products are often used duri...

Examples

Embodiment 1

[0014] A preparation method of high-suspension, strong rheology, anti-bleeding cellulose ether, comprising the following steps:

[0015] (1) Preparation of cellulose ether with a viscosity of 400-1000mpa.s: impregnate the refined cotton with a 40% NaOH solution for 1 hour, then carry out alkalization treatment at 30°C, then seal the reactor and vacuumize it, and add A certain amount of etherification agent, the etherification agent is one of methyl chloride, propylene oxide, methyl chloride, and ethylene oxide, wherein the mass ratio of cotton fiber to etherification agent is 1:1.5-2.0, and then slowly heat up to React at 40°C for 2 hours, continue to heat up and react at 70°C for 1.5 hours, the prepared cellulose ether is at least one of hydroxypropyl methylcellulose ether or hydroxyethyl methylcellulose ether, the initiator It is at least one of potassium persulfate or sodium persulfate;

[0016] (2) Carry out modification and substitution treatment on the cellulose ether p...

Embodiment 2

[0018] The difference between Example 2 and Example 1 is that: when performing rheology modification treatment, the ratio of each component is roughly 2:1 by mass ratio of cellulose ether to water-soluble rheological polymerization modification monomer, wherein The water-soluble rheological polymerization modified monomer is ethylene oxide monomer and acrylamide monomer mixed at a ratio of 1:1, and the prepared cellulose has a viscosity of 430mpa.s.

Embodiment 3

[0020] The difference between Example 3 and Example 1 is that: when performing rheology modification treatment, the ratio of each component is approximately 3:1 by mass ratio of cellulose ether to water-soluble rheological polymerization modification monomer, wherein The water-soluble rheological polymerization modified monomer is 1:1 mixed substitution of ethylene oxide monomer and acrylamide monomer, and the viscosity of the prepared cellulose is 450mpa.s.

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