Primary polyether as well as preparation method and application thereof

Abstract

The invention provides primary polyether as well as a preparation method and application thereof, and belongs to the technical field of water reducing agents. The preparation method comprises the following steps: carrying out catalytic esterification reaction on pentaerythritol and 2, 2-dimethylolpropionic acid, reacting with a polyether macromonomer and maleic anhydride to prepare a carboxyl-terminated polyether macromonomer, carrying out mixed esterification reaction, further reacting with sulfamic acid, reacting with graphene oxide, and mixing with intercalated montmorillonite to prepare primary polyether; the primary polyether prepared by the invention is large in three-dimensional structure volume, avoids cement particle flocculation, has both dispersity and mud resistance, can improve the mechanical property of a cement-based material, and realizes a slow release function, so that the release rate of a polyether monomer is controlled, the dispersion retention capability is improved, and the primary polyether has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of water-reducing agents, and particularly relates to a primary polyether and a preparation method and application thereof. BACKGROUND

[0002] Although the high-performance concrete technology is widely applied, with the service environment of the concrete becoming worse and worse, the performance defects of the concrete itself under extreme environmental conditions are gradually highlighted, and in particular, the durability of the concrete structure needs to be further researched. For example, how to improve the chloride ion penetration resistance of the marine engineering concrete which has the problems of cracking and steel bar corrosion will be the biggest problem of the marine engineering concrete.

[0003] The primary polyether, also known as a polyether macromonomer, is an important raw material for synthesizing polycarboxylic acid water-reducing agents, and the molecular structure of the primary polyether is a key factor influencing the performance of the polycarboxylic acid water-reducing agent. In recent years, the market of the polyether macromonomer has been continuously developed, and the product structure has obviously changed, and new polyether macromonomer products with functions emerge in an endless stream, fully reflecting the rapid development of the polycarboxylic acid water-reducing agent macromonomer industry chain and the continuous improvement of the product quality. The performance requirements for the polycarboxylic acid water-reducing agent in the market are getting higher and higher, and although the current polyether macromonomer can meet most of the requirements, there are still defects and deficiencies, such as poor clay resistance, so it is necessary to further improve the performance of the polycarboxylic acid water-reducing agent; and the research on the polyether macromonomer with a special molecular structure is less, and it is difficult to meet the demand, such as super high-performance concrete.

[0004] The cement-based material is a kind of multi-material and multi-scale composite, in which the hydration product calcium silicate gel has a nanoscale, and more than 90% of the gel pores are nanoscale in size, in combination with the four types of pore size classification method of Academician Wu Zhongwei, the appearance of the nanomaterial provides another way for the preparation of the high-performance cement-based material. Small-sized nanoparticles can fill part of the micropores in the cement stone, improve the microstructure of the concrete interface, and thus improve the strength and durability of the concrete. At present, the research on the nanomaterial in the concrete is still in the initial stage, and there are many problems in theory and practical application. SUMMARY

[0005] The primary polyether and the preparation method and application thereof provided by the application have a large three-dimensional structure volume, can avoid the flocculation of cement particles, have good dispersibility and clay resistance, can improve the mechanical properties of the cement-based material, realize the slow-release function, control the release rate of the polyether monomer, improve the dispersion and retention capacity, and have a wide application prospect.

[0006] The technical scheme of the application is implemented as follows:

[0007] The application provides a preparation method of a primary polyether, which comprises the following steps: performing catalytic esterification reaction on pentaerythritol and 2,2-dimethylol propionic acid, and then performing reaction on the obtained product with polyether macromonomer and maleic anhydride to obtain a carboxyl-terminated polyether macromonomer mixed esterification product, further performing reaction on the carboxyl-terminated polyether macromonomer mixed esterification product with sulfamic acid, and then performing reaction on the obtained product with graphene oxide, and finally mixing the obtained product with intercalated montmorillonite to obtain the primary polyether.

[0008] As a further improvement of the application, the following steps are included:

[0009] S1. performing catalytic esterification reaction on pentaerythritol and 2,2-dimethylol propionic acid to obtain a hydroxyl-terminated hyperbranched polyester;

[0010] S2. performing reaction on polyether macromonomer and maleic anhydride to obtain a carboxyl-terminated polyether macromonomer;

[0011] S3. performing catalytic esterification reaction on the carboxyl-terminated polyether macromonomer and the hydroxyl-terminated hyperbranched polyester to obtain a hyperbranched macromonomer;

[0012] S4. mixing the hyperbranched macromonomer with sulfamic acid, adding urea, and performing heating reaction under protection of inert gas, then dissolving the obtained product in ethanol, filtering, and removing the solvent from the filtrate under reduced pressure to obtain a sulfonate grafted hyperbranched macromonomer;

[0013] S5. dissolving octadecyl dimethyl benzyl ammonium chloride in water, adding sodium-based montmorillonite, and performing intercalation by heating and stirring to obtain intercalated montmorillonite;

[0014] S6. uniformly dispersing graphene oxide in water, adding 1-ethyl-3-(3-dimethylamino propyl) carbodiimide and N-hydroxysuccinimide, stirring and activating, adding the sulfonate grafted hyperbranched macromonomer, performing heating and stirring reaction, adding the intercalated montmorillonite, performing heating and stirring, filtering, washing, and drying to obtain the primary polyether.

[0015] As a further improvement of the application, the molar ratio of the pentaerythritol and the 2,2-dimethylol propionic acid in step S1 is 1:5-8, and a catalyst is further added, wherein the catalyst is p-toluenesulfonic acid, the addition amount of the catalyst is 3-5 wt% of the pentaerythritol, the reaction temperature is 120-140 DEG C, and the reaction time is 4-6 h.

[0016] As a further improvement of the application, the molar ratio of the polyether macromonomer and the maleic anhydride in step S2 is 1.5-2.5:1, and a catalyst is further added, wherein the catalyst is 4-dimethylamino pyridine, the reaction temperature is 80-90 DEG C, the reaction time is 5-7 h, and the polyether macromonomer is allyl polyoxyethylene ether, methyl allyl polyoxyethylene ether or isopentenyl polyoxyethylene ether.

[0017] As a further improvement of the present application, the mass ratio of the terminal carboxyl polyether macromonomer and the terminal hydroxyl hyperbranched polyester in step S3 is 7-10:5, and a catalyst is further added, the catalyst is p-toluenesulfonic acid or concentrated sulfuric acid, the addition amount of the catalyst is 3-5wt% of the terminal hydroxyl hyperbranched polyester, the reaction temperature is 110-130℃, and the reaction time is 5-7h.

[0018] As a further improvement of the present application, the mass ratio of the hyperbranched macromonomer and the amino sulfonic acid in step S4 is 10:0.5-1, and the reaction temperature is 135-145℃, and the reaction time is 4-6h.

[0019] As a further improvement of the present application, the mass ratio of the octadecyl dimethyl benzyl ammonium chloride and the sodium-based montmorillonite in step S5 is 2-3:10, and the temperature of the heating and stirring intercalation is 45-55℃, and the time is 1-3h.

[0020] As a further improvement of the present application, the mass ratio of the graphene oxide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, N-hydroxysuccinimide, sulfonate grafted hyperbranched macromonomer and intercalated montmorillonite in step S6 is 3-5:1-2:1-2:10-12:25-35, the temperature of the heating and stirring reaction is 45-55℃, the time is 2-4h, and the time of the heating and stirring is 0.5-1.5h.

[0021] The present application further protects a primary polyether prepared by the above preparation method.

[0022] The present application further protects the use of the above primary polyether in the preparation of a concrete water reducing agent.

[0023] The present application has the following beneficial effects:

[0024] The traditional polyether-based water reducing agent is mainly a comb structure, which is easily adsorbed between clay layers and has poor mud resistance, therefore, the primary polyether prepared by the present application first takes the terminal hydroxyl hyperbranched polyester as the core, and then reacts with the terminal carboxyl polyether macromonomer to prepare a hyperbranched macromonomer, and the molecular chain is changed to a hyperbranched structure, which has a large three-dimensional structure and remarkable mud resistance. At the same time, the hyperbranched structure can also enhance the steric hindrance, avoid the flocculation of cement particles, and balance the dispersibility and mud resistance.

[0025] The present application reacts the residual hydroxyl groups on the hyperbranched macromonomer with amino sulfonic acid to introduce strong ionized sulfonic acid groups, giving the molecule a high negative charge density, introducing sulfonic acid groups, enhancing the main chain rigidity, reducing the molecular chain curling, and at the same time improving the overall charge density of the main chain, strengthening the binding capacity with the surface Ca 2+ of the cement particles, improving the selective adsorption of the cement, and reducing the probability of being adsorbed by clay.

[0026] The graphene oxide is activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, and is reacted with a sulfonate grafted hyperbranched macromonomer, the carboxyl functional groups on the surface of the graphene oxide are reacted with the hydration product calcium hydroxide, the graphene oxide is connected with each other in the cement hydration product to form a three-dimensional network structure to improve the mechanical properties of the cement-based material. Due to the thin grid effect and migration effect of the two-dimensional graphene material, the graphene can be enriched in the aggregate and cementitious material interface zone, more nucleation sites are provided, and a stronger bridging effect is realized; meanwhile, the graphene material can also adsorb interlayer water in the interface zone, reduce the water-cement ratio between the interfaces, and improve the interface microstructure. The graphene oxide has a template effect in the cement hydration process, and thick rod-shaped hydration crystals and flower-shaped crystals are formed on the surface of the graphene oxide by using the numerous nucleation sites on the template, when the columnar crystals grow at the holes, cracks or loose structures of the hydration product, they will freely grow to form flower-shaped crystals, which act as fillers and anti-cracking components in the pores and cracks to delay crack propagation. In addition, the graphene oxide can provide nucleation sites to promote the growth of calcium silicate hydrate, calcium hydroxide and ettringite.

[0027] Finally, the montmorillonite subjected to organic intercalation is mixed and stirred with the final product, the hyperbranched macromonomer is introduced into the interlayer by electrostatic interaction and hydrogen bonding to form a "sandwich" structure, the slow-release function is realized, the release rate of the polyether monomer is controlled, the dispersion retention capacity is improved, the montmorillonite modified by the quaternary ammonium salt can preferentially adsorb free clay ions, the consumption of the polyether by the clay is reduced, and the "failure" problem of the traditional water reducing agent in the machine-made sand is solved.

[0028] The primary polyether three-dimensional structure prepared in the application has a large volume, avoids the flocculation of cement particles, has good dispersibility and mud resistance, can improve the mechanical properties of the cement-based material, realizes the slow-release function, controls the release rate of the polyether monomer, improves the dispersion retention capacity, and has a wide application prospect. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the application will be clearly and completely described below, obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0030] Graphene oxide, flake diameter, 2-4 μm, thickness 0.8-1.2 nm.

[0031] Embodiment 1

[0032] The embodiment provides a preparation method of a primary polyether, which comprises the following steps:

[0033] S1. 0.1 mol pentaerythritol and 0.5 mol 2,2-dimethylol propionic acid were added into 200 mL dimethyl sulfoxide, stirred and mixed uniformly, 3 wt% of p-toluene sulfonic acid based on pentaerythritol was added under nitrogen protection, heated to 120℃, stirred and reacted for 4 h, recrystallized with toluene, filtered, washed and dried to obtain a hydroxyl-terminated hyperbranched polyester;

[0034] S2. 0.15 mol allyl polyoxyethylene ether and 0.1 mol maleic anhydride were mixed, 2 wt% of 4-dimethylamino pyridine based on the polyether macromonomer was added under nitrogen protection, heated to 80℃, stirred and reacted for 5 h, the product was dissolved in dichloromethane, washed with water, and the solvent was removed under reduced pressure to obtain a carboxyl-terminated polyether macromonomer;

[0035] S3. 7 g of the carboxyl-terminated polyether macromonomer and 5 g of the hydroxyl-terminated hyperbranched polyester were dissolved in 150 mL N,N-dimethylformamide, 3 wt% of p-toluene sulfonic acid based on the hydroxyl-terminated hyperbranched polyester was added under nitrogen protection, heated to 110℃, stirred and reacted for 5 h to obtain a hyperbranched macromonomer;

[0036] S4. 10 g of the hyperbranched macromonomer and 0.5 g of sulfamic acid were mixed, 50 g of urea was added, heated to 135℃ under nitrogen protection, stirred and reacted for 4 h, cooled to room temperature, dissolved in ethanol, filtered, and the filtrate was dried under reduced pressure to obtain a sulfonate grafted hyperbranched macromonomer;

[0037] S5. 2 g of octadecyl dimethyl benzyl ammonium chloride was dissolved in 100 mL water, 10 g of sodium-based montmorillonite was added, heated to 45℃, intercalated for 1 h, filtered, washed and dried to obtain an intercalated montmorillonite;

[0038] S6. 3 g of graphene oxide was uniformly dispersed in 500 mL water, 1 g of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1 g of N-hydroxysuccinimide were added, stirred and activated for 30 min, 10 g of the sulfonate grafted hyperbranched macromonomer was added, heated to 45℃, stirred and reacted for 2 h, 25 g of the intercalated montmorillonite was added, heated and stirred for 0.5 h, filtered, washed and dried to obtain a primary polyether.

[0039] Through infrared spectrum analysis, there was a clear -N-H absorption peak at 3428 cm -1 , a strong and wide -OH characteristic absorption peak appeared near 3410 cm -1 , -CH2- stretching vibration peak was at 2868 cm -1 , there were clear -C=C- absorption peaks at 1657 cm -1 , and clear -C=O absorption peaks at 1480 cm -1 , and 1355 cm -1with an obvious -S=0 absorption peak, 1495 cm -1 with a -CN stretching vibration absorption peak, 1093 cm -1 , 1078 cm -1 and 1051 cm -1 with a -CH2-0-CH2- stretching vibration peak, 915-1100 cm -1 with a -SiO stretching vibration peak of the layered aluminosilicate, indicating that the compound is successfully synthesized.

[0040] Example 2

[0041] This embodiment provides a method for preparing a primary polyether, comprising the following steps:

[0042] S1. 0.1 mol of pentaerythritol and 0.8 mol of 2,2-dimethylol propionic acid are added to 200 mL of dimethyl sulfoxide, stirred and mixed uniformly, 5 wt% of p-toluenesulfonic acid based on pentaerythritol is added under nitrogen protection, heated to 140°C, stirred for 6 h, recrystallized with toluene, filtered, washed, and dried to obtain a hydroxyl-terminated hyperbranched polyester;

[0043] S2. 0.25 mol of methyl allyl polyoxyethylene ether and 0.1 mol of maleic anhydride are mixed, 4-dimethylaminopyridine is added under nitrogen protection, accounting for 3 wt% of the polyether macromonomer, heated to 90°C, stirred for 7 h, the product is dissolved in dichloromethane, washed with water, and the solvent is removed under reduced pressure to obtain a carboxyl-terminated polyether macromonomer;

[0044] S3. 10 g of the carboxyl-terminated polyether macromonomer and 5 g of the hydroxyl-terminated hyperbranched polyester are dissolved in 150 mL of N,N-dimethylformamide, concentrated sulfuric acid is added under nitrogen protection, accounting for 5 wt% of the hydroxyl-terminated hyperbranched polyester, heated to 130°C, stirred for 7 h to obtain a hyperbranched macromonomer;

[0045] S4. 10 g of the hyperbranched macromonomer and 1 g of sulfamic acid are mixed, 50 g of urea is added, heated to 145°C under nitrogen protection, stirred for 6 h, cooled to room temperature, dissolved in ethanol, filtered, and the filtrate is removed under reduced pressure to obtain a sulfonate grafted hyperbranched macromonomer;

[0046] S5. 3 g of octadecyl dimethyl benzyl ammonium chloride is dissolved in 100 mL of water, 10 g of sodium-based montmorillonite is added, heated to 55°C, stirred for 3 h, filtered, washed, and dried to obtain an intercalated montmorillonite;

[0047] S6. 5 g of graphene oxide was uniformly dispersed in 500 mL of water, 2 g of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 2 g of N-hydroxysuccinimide were added, stirred and activated for 30 min, 12 g of sulfonate grafted hyperbranched macromonomer was added, heated to 55°C, stirred and reacted for 4 h, 35 g of intercalated montmorillonite was added, heated and stirred for 1.5 h, filtered, washed, dried, and a primary polyether was prepared.

[0048] Example 3

[0049] The present example provides a method for preparing a primary polyether, comprising the following steps:

[0050] S1. 0.1 mol of pentaerythritol and 0.65 mol of 2,2-dimethylol propionic acid were added to 200 mL of dimethyl sulfoxide, stirred and mixed uniformly, 4 wt% of p-toluenesulfonic acid based on pentaerythritol was added under nitrogen protection, heated to 130°C, stirred and reacted for 5 h, recrystallized with toluene, filtered, washed, and dried to obtain a hydroxyl-terminated hyperbranched polyester;

[0051] S2. 0.2 mol of isopentenyl polyoxyethylene ether and 0.1 mol of maleic anhydride were mixed, 4-dimethylaminopyridine was added under nitrogen protection, 2.5 wt% based on the polyether macromonomer, heated to 85°C, stirred and reacted for 6 h, the product was dissolved in dichloromethane, washed with water, and the solvent was removed under reduced pressure to obtain a carboxyl-terminated polyether macromonomer;

[0052] S3. 8.5 g of carboxyl-terminated polyether macromonomer and 5 g of hydroxyl-terminated hyperbranched polyester were dissolved in 150 mL of N,N-dimethylformamide, 4 wt% of p-toluenesulfonic acid based on the hydroxyl-terminated hyperbranched polyester was added under nitrogen protection, heated to 120°C, stirred and reacted for 6 h to obtain a hyperbranched macromonomer;

[0053] S4. 10 g of hyperbranched macromonomer and 0.7 g of sulfamic acid were mixed, 50 g of urea was added, heated to 140°C under nitrogen protection, stirred and reacted for 5 h, cooled to room temperature, dissolved in ethanol, filtered, and the filtrate was dried under reduced pressure to obtain a sulfonate grafted hyperbranched macromonomer;

[0054] S5. 2.5 g of octadecyl dimethyl benzyl ammonium chloride was dissolved in 100 mL of water, 10 g of sodium-based montmorillonite was added, heated to 50°C, intercalated and stirred for 2 h, filtered, washed, and dried to obtain an intercalated montmorillonite;

[0055] S6. 4 g of graphene oxide was uniformly dispersed in 500 mL of water, 1.5 g of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1.5 g of N-hydroxysuccinimide were added, stirred and activated for 30 min, 11 g of sulfonate grafted hyperbranched macromonomer was added, heated to 50°C, stirred and reacted for 3 h, 30 g of intercalated montmorillonite was added, heated and stirred for 1 h, filtered, washed, dried, and a primary polyether was prepared.

[0056] Comparative Example 1

[0057] Compared with Example 3, the difference lies in that steps S1, S3 and S4 are not performed.

[0058] The following steps are included:

[0059] S1. 0.2 mol of isopentenyl polyoxyethylene ether and 0.1 mol of maleic anhydride were mixed, 4-dimethylaminopyridine accounting for 2.5 wt% of the polyether macromonomer was added under nitrogen protection, heated to 85°C, stirred and reacted for 6 h, the product was dissolved in dichloromethane, washed with water, and the solvent was removed under reduced pressure to prepare a carboxyl-terminated polyether macromonomer;

[0060] S2. 2.5 g of octadecyl dimethyl benzyl ammonium chloride was dissolved in 100 mL of water, 10 g of sodium-based montmorillonite was added, heated to 50°C, intercalated and stirred for 2 h, filtered, washed, dried, and an intercalated montmorillonite was prepared.

[0061] S3. 11 g of carboxyl-terminated polyether macromonomer was uniformly dispersed in 500 mL of water, 1.5 g of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1.5 g of N-hydroxysuccinimide were added, stirred and activated for 30 min, 4 g of graphene oxide was added, heated to 50°C, stirred and reacted for 3 h, 30 g of intercalated montmorillonite was added, heated and stirred for 1 h, filtered, washed, dried, and a primary polyether was prepared.

[0062] Comparative Example 2

[0063] Compared with Example 3, the difference lies in that step S4 is not performed.

[0064] The following steps are included:

[0065] S1. 0.1 mol of pentaerythritol and 0.65 mol of 2,2-dimethylol propionic acid were added to 200 mL of dimethyl sulfoxide, stirred and mixed uniformly, p-toluenesulfonic acid accounting for 4 wt% of the pentaerythritol was added under nitrogen protection, heated to 130°C, stirred and reacted for 5 h, recrystallized with toluene, filtered, washed, and dried to prepare a hydroxyl-terminated hyperbranched polyester;

[0066] S2. 0.2 mol of isopentenyl polyoxyethylene ether and 0.1 mol of maleic anhydride were mixed, 4-dimethylaminopyridine accounting for 2.5 wt% of the polyether macromonomer was added under nitrogen protection, heated to 85°C, stirred for 6 h, the product was dissolved in dichloromethane, washed with water, and the solvent was removed under reduced pressure to obtain a carboxyl-terminated polyether macromonomer;

[0067] S3. 8.5 g of the carboxyl-terminated polyether macromonomer and 5 g of the hydroxyl-terminated hyperbranched polyester were dissolved in 150 mL of N,N-dimethylformamide, p-toluenesulfonic acid accounting for 4 wt% of the hydroxyl-terminated hyperbranched polyester was added under nitrogen protection, heated to 120°C, and stirred for 6 h to obtain a hyperbranched macromonomer;

[0068] S4. 2.5 g of octadecyl dimethyl benzyl ammonium chloride was dissolved in 100 mL of water, 10 g of sodium-based montmorillonite was added, heated to 50°C, and intercalated for 2 h, then filtered, washed, and dried to obtain intercalated montmorillonite;

[0069] S5. 4 g of graphene oxide was uniformly dispersed in 500 mL of water, 1.5 g of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1.5 g of N-hydroxysuccinimide were added, stirred for 30 min for activation, 11 g of the hyperbranched macromonomer was added, heated to 50°C, and stirred for 3 h, then 30 g of the intercalated montmorillonite was added, heated and stirred for 1 h, filtered, washed, and dried to obtain a primary polyether.

[0070] Comparative Example 3

[0071] Compared with Example 3, the difference is that no graphene oxide is added in step S6.

[0072] The following steps are included:

[0073] S1. 0.1 mol of pentaerythritol and 0.65 mol of 2,2-dimethylol propionic acid were added to 200 mL of dimethyl sulfoxide, stirred and mixed uniformly, 4-toluenesulfonic acid accounting for 4 wt% of the pentaerythritol was added under nitrogen protection, heated to 130°C, and stirred for 5 h, then recrystallized from toluene, filtered, washed, and dried to obtain a hydroxyl-terminated hyperbranched polyester;

[0074] S2. 0.2 mol of isopentenyl polyoxyethylene ether and 0.1 mol of maleic anhydride were mixed, 4-dimethylaminopyridine accounting for 2.5 wt% of the polyether macromonomer was added under nitrogen protection, heated to 85°C, stirred for 6 h, the product was dissolved in dichloromethane, washed with water, and the solvent was removed under reduced pressure to obtain a carboxyl-terminated polyether macromonomer;

[0075] S3. 8.5 g of carboxyl-terminated polyether macromonomer and 5 g of hydroxyl-terminated hyperbranched polyester were dissolved in 150 mL of N,N-dimethylformamide, 4 wt% of p-toluenesulfonic acid based on the hydroxyl-terminated hyperbranched polyester was added under nitrogen protection, heated to 120°C, and stirred for 6 h to prepare a hyperbranched macromonomer;

[0076] S4. 10 g of the hyperbranched macromonomer and 0.7 g of sulfamic acid were mixed, 50 g of urea was added, heated to 140°C under nitrogen protection, stirred for 5 h, cooled to room temperature, dissolved in ethanol, filtered, and the filtrate was concentrated under reduced pressure to prepare a sulfonate grafted hyperbranched macromonomer;

[0077] S5. 2.5 g of octadecyl dimethyl benzyl ammonium chloride was dissolved in 100 mL of water, 10 g of sodium-based montmorillonite was added, heated to 50°C, and intercalated for 2 h, filtered, washed, and dried to prepare an intercalated montmorillonite;

[0078] S6. 1.5 g of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1.5 g of N-hydroxysuccinimide were added to 500 mL of water, stirred for 30 min, 11 g of the sulfonate grafted hyperbranched macromonomer was added, heated to 50°C, and stirred for 3 h, 30 g of the intercalated montmorillonite was added, heated and stirred for 1 h, filtered, washed, and dried to prepare a primary polyether.

[0079] Comparative Example 4

[0080] Compared with Example 3, the difference is that no intercalated montmorillonite was added in step S6.

[0081] Comprising the following steps:

[0082] S1. 0.1 mol of pentaerythritol and 0.65 mol of 2,2-dimethylol propionic acid were added to 200 mL of dimethyl sulfoxide, stirred and mixed uniformly, 4 wt% of p-toluenesulfonic acid based on the pentaerythritol was added under nitrogen protection, heated to 130°C, and stirred for 5 h to prepare a hydroxyl-terminated hyperbranched polyester;

[0083] S2. 0.2 mol of isopentenyl polyoxyethylene ether and 0.1 mol of maleic anhydride were mixed, 4-dimethylaminopyridine was added under nitrogen protection, 2.5 wt% based on the polyether macromonomer, heated to 85°C, and stirred for 6 h, the product was dissolved in dichloromethane, washed with water, and concentrated under reduced pressure to prepare a carboxyl-terminated polyether macromonomer;

[0084] S3. 8.5 g of carboxyl-terminated polyether macromonomer and 5 g of hydroxyl-terminated hyperbranched polyester were dissolved in 150 mL of N,N-dimethylformamide, 4 wt% of p-toluenesulfonic acid based on the hydroxyl-terminated hyperbranched polyester was added under nitrogen protection, heated to 120°C, and stirred for 6 h to obtain a hyperbranched macromonomer;

[0085] S4. 10 g of the hyperbranched macromonomer and 0.7 g of sulfamic acid were mixed, 50 g of urea was added, heated to 140°C under nitrogen protection, stirred for 5 h, cooled to room temperature, dissolved in ethanol, filtered, and the filtrate was concentrated under reduced pressure to obtain a sulfonate grafted hyperbranched macromonomer;

[0086] S5. 4 g of graphene oxide was uniformly dispersed in 500 mL of water, 1.5 g of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1.5 g of N-hydroxysuccinimide were added, stirred for 30 min, 11 g of the sulfonate grafted hyperbranched macromonomer was added, heated to 50°C, stirred for 3 h, filtered, washed, and dried to obtain a primary polyether.

[0087] Test Example 1

[0088] The primary polyethers prepared in Examples 1-3 and Comparative Examples 1-4 were diluted with water to a solid content of 60%, 300 parts were taken, then 3 parts of 30 wt% hydrogen peroxide was added to obtain solution A; 28 parts of acrylic acid and 1.5 parts of mercaptopropionic acid were mixed with 50 parts of water to obtain solution B; 0.8 parts of reducing agent E51 was weighed and dissolved in 60 parts of water to obtain solution C; solution B was added dropwise to solution A for 2 h, and solution C was added dropwise for 3 h; the temperature was allowed to rise naturally during the dropwise addition, and the temperature was maintained for 1 h after the dropwise addition was completed; 20% liquid alkali was used for neutralization until the pH was 6 to obtain a polycarboxylic acid water reducer product, and performance tests were conducted.

[0089] The cement used was ordinary Portland cement (P.O 42.5), and the dispersion performance and dispersion retention performance of the prepared water reducer were compared. The cement paste fluidity test was conducted according to the GB8077-2023 standard, 300 g of cement was added with 87 g of water, stirred for 4 min, and then the cement paste fluidity was measured on a flat glass plate, and the paste fluidity at different times was tested. The results are shown in Table 1.

[0090] Table 1

[0091]

[0092] As can be seen from the above table, the water reducer prepared from the primary polyether prepared in Examples 1-3 improves the water reducing and dispersing effect, improves the slump retention performance, and improves the anti-mud performance.

[0093] The compressive strength of hardened concrete was determined according to the relevant test method in GB 8076-2008 standard. The results are shown in Table 2.

[0094] Table 2

[0095]

[0096] From the above table, it can be seen that the water reducing agent prepared from the primary polyether prepared in Examples 1-3 can obviously improve the mechanical properties of concrete.

[0097] The above description is merely preferred embodiments of the present application, but not to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the preparation of a primary polyether, characterized in that, The primary polyether is prepared by the following steps:

2. The production method according to claim 1, characterized by, S1. The pentaerythritol and 2,2-dimethylol propionic acid are subjected to catalytic esterification reaction to prepare a hydroxyl-terminated hyperbranched polyester; S2. The polyether macromonomer and maleic anhydride are reacted to prepare a carboxyl-terminated polyether macromonomer; S3. The carboxyl-terminated polyether macromonomer and the hydroxyl-terminated hyperbranched polyester are subjected to catalytic esterification reaction to prepare a hyperbranched macromonomer; S4. The hyperbranched macromonomer and amino sulfonic acid are mixed, urea is added, and the mixture is heated under inert gas protection to react, ethanol is added for dissolution, filtration is performed, and the filtrate is subjected to solvent removal under reduced pressure to prepare a sulfonate grafted hyperbranched macromonomer; S5. The octadecyl dimethyl benzyl ammonium chloride is dissolved in water, sodium-based montmorillonite is added, and the mixture is subjected to heating and stirring intercalation to prepare an intercalated montmorillonite; S6. The graphene oxide is uniformly dispersed in water, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide are added, stirring is performed for activation, the sulfonate grafted hyperbranched macromonomer is added, heating and stirring are performed for reaction, the intercalated montmorillonite is added, heating and stirring are performed, filtration is performed, washing is performed, and drying is performed to prepare the primary polyether. In step S1, the molar ratio of the pentaerythritol and 2,2-dimethylol propionic acid is 1:5-8, a catalyst is added, the catalyst is p-toluenesulfonic acid, the catalyst is added in an amount of 3-5 wt% of the pentaerythritol, the reaction temperature is 120-140°C, and the reaction time is 4-6h.

3. The preparation method according to claim 2, characterized in that, In step S2, the molar ratio of the polyether macromonomer and maleic anhydride is 1.5-2.5:1, a catalyst is added, the catalyst is 4-dimethylaminopyridine, the reaction temperature is 80-90°C, the reaction time is 5-7h, and the polyether macromonomer is allyl polyoxyethylene ether, methyl allyl polyoxyethylene ether, or isopentenyl polyoxyethylene ether.

4. The production method according to claim 2, characterized by, In step S3, the mass ratio of the carboxyl-terminated polyether macromonomer and the hydroxyl-terminated hyperbranched polyester is 7-10:5, a catalyst is added, the catalyst is p-toluenesulfonic acid or concentrated sulfuric acid, the catalyst is added in an amount of 3-5 wt% of the hydroxyl-terminated hyperbranched polyester, the reaction temperature is 110-130°C, and the reaction time is 5-7h.

5. The preparation method according to claim 2, characterized in that, In step S4, the mass ratio of the hyperbranched macromonomer and amino sulfonic acid is 10:0.5-1, the reaction temperature is 135-145°C, and the reaction time is 4-6h.

6. The preparation method according to claim 2, characterized in that, In step S5, the mass ratio of the octadecyl dimethyl benzyl ammonium chloride and sodium-based montmorillonite is 2-3:10, the temperature for heating and stirring intercalation is 45-55°C, and the time for heating and stirring intercalation is 1-3h.

7. The preparation method according to claim 2, characterized in that, ​ 8. The preparation method according to claim 2, characterized in that, The mass ratio of the graphene oxide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, N-hydroxysuccinimide, sulfonate grafted hyperbranched macromonomer, intercalated montmorillonite in step S6 is 3-5:1-2:1-2:10-12:25-35, the temperature of the heating and stirring reaction is 45-55℃, the time is 2-4h, and the time of the heating and stirring is 0.5-1.5h.

9. A primary polyether prepared according to the process of any one of claims 1 to 8.

10. Use of a primary polyether according to claim 9 for the preparation of a concrete water reducer.

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