Calcium Carbonate Oligomer Synergistically Enhancing Zwitterionic Polymer Materials, Preparation Method Thereof and Application

Abstract

The present invention discloses a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material with APTS-POSS, its preparation method and application. Using methacryloyloxyethyl phosphorylcholine and 2-hydroxyethyl methacrylate as reaction monomers for free radical polymerization reaction, purifying and drying the reaction product and dissolving it in an organic solvent to obtain a zwitterionic polymer solution; dissolving γ-glycidoxypropyl trisiloxane and 3-aminopropyltriethoxysilane in an organic solvent and heating and reacting to obtain an APTS-POSS solution; blending the calcium carbonate oligomer solution, the zwitterionic polymer solution and the APTS-POSS solution to obtain a blended solution, and the blended solution is the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material with APTS-POSS. The present invention can enhance the structural strength of sandstone cultural relics and accelerate the outward migration rate of soluble salts in sandstone cultural relics, which is beneficial to improving the anti-salt weathering performance of sandstone cultural relics.

Description

Technical Field

[0001] The present invention belongs to the technical field of sandstone cultural relic protection, and specifically relates to a calcium carbonate oligomer synergistic APTS-POSS enhanced zwitterionic polymer material, a preparation method thereof, and an application thereof. Background Art

[0002] Sandstone cultural relics are important carriers witnessing the characteristics of Chinese culture and the history of Chinese and foreign cultural exchanges. However, they have relatively large porosity, expansion coefficient, and water absorption coefficient, and their own structural strength is not high. Under the long-term influence of natural environmental factors, a series of weathering phenomena that affect the safety and integrity of sandstone cultural relics, such as surface pulverization, layered exfoliation, and local hollowing, have occurred in most large-scale immovable sandstone cultural relics outdoors. Soluble salts are the main weathering factors causing diseases of outdoor sandstone cultural relics. As the environmental temperature decreases or the water in the pores volatilizes, these soluble salt components (especially Na2SO4) will crystallize at high supersaturation, thereby generating huge crystallization pressure and causing a decrease in the structural strength of sandstone cultural relics.

[0003] Implementing rescue bonding and reinforcement of fragile sandstone cultural relics through protective materials, while delaying or inhibiting the crystallization of Na2SO4, reducing its crystallization pressure, and promoting the migration of soluble salts to the surface of sandstone cultural relics with water for removal, is an effective way to scientifically solve salt crystallization weathering. However, the hydrophobic protective materials reported currently will block the water / salt migration path, resulting in the accumulation of soluble salts at the hydrophilic-hydrophobic interface and accelerating the deterioration of sandstone; the hydrophilic protective materials will reduce the functional aging effect because they are easily detached from the sandstone cultural relics body. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the present invention provides a calcium carbonate oligomer synergistic APTS-POSS enhanced zwitterionic polymer material, a preparation method thereof, and an application thereof, which can enhance the structural strength of sandstone cultural relics and accelerate the outward migration rate of soluble salts in sandstone cultural relics, and is beneficial to improving the anti-salt weathering performance of sandstone cultural relics.

[0005] In order to solve the above technical problems, the present invention is realized through the following technical solutions:

[0006] A preparation method of a calcium carbonate oligomer synergistic APTS-POSS enhanced zwitterionic polymer material, comprising:

[0007] Performing a free radical polymerization reaction with methacryloyloxyethyl phosphorylcholine and 2-hydroxyethyl methacrylate as reaction monomers, purifying and drying the reaction product, and dissolving it in an organic solvent to obtain a zwitterionic polymer solution;

[0008] Dissolving γ-glycidoxypropyl heptaisobutyl POSS and 3-aminopropyltriethoxysilane in an organic solvent, and heating and reacting to obtain an APTS-POSS solution;

[0009] Mix the calcium carbonate oligomer solution, the zwitterionic polymer solution, and the APTS-POSS solution to obtain a blended solution, which is the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material with APTS-POSS.

[0010] Further, the total mass fraction of the solutes in the blended solution is 1 wt% - 5 wt%. Among them, the calcium carbonate oligomer accounts for 5 wt% - 15 wt% of the mass of the zwitterionic polymer, and APTS-POSS accounts for 20 wt% - 80 wt% of the total mass of the solutes.

[0011] Further, the total mass concentration of methacryloyloxyethyl phosphorylcholine and 2-hydroxyethyl methacrylate is 1 wt% - 5 wt%, and the molar ratio of methacryloyloxyethyl phosphorylcholine to 2-hydroxyethyl methacrylate is 3:1 - 1:1.

[0012] Further, the temperature during the free radical polymerization reaction is 65 °C - 75 °C.

[0013] Further, the total mass concentration of γ-glycidoxypropyl octasilsesquioxane and 3-aminopropyltriethoxysilane is 1 wt% - 6 wt%, and the molar ratio of γ-glycidoxypropyl octasilsesquioxane to 3-aminopropyltriethoxysilane is 4:3.

[0014] Further, when preparing the APTS-POSS solution, the heating temperature is 46 °C - 50 °C.

[0015] Further, the mass fraction of the calcium carbonate oligomer solution is 0.10 wt% - 0.35 wt%.

[0016] A calcium carbonate oligomer synergistically enhanced zwitterionic polymer material is prepared by using the described preparation method.

[0017] An application of a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material is to suspend and infiltrate the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material into the sandstone cultural relics to be protected for protecting the sandstone cultural relics.

[0018] An application of a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material is to mix the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material with pulp to obtain desalinated pulp;

[0019] Apply the desalinated pulp to the surface of the sandstone cultural relics to be protected, and spray water on the desalinated pulp in the form of water mist every 6 h - 12 h to protect the sandstone cultural relics.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] In the present invention, the synthesized PMH is an amphoteric ion copolymer, and its side-chain phosphorylcholine contains immobile positive / negative electric groups, so it has an anti-polyelectrolyte effect. In a salt solution, it can perform electrostatic adsorption-desorption cycles with salt ions, and thus can promote the diffusion of salt ions from the high-concentration end to the low-concentration end under the drive of capillary action and concentration gradient. At the same time, the phosphorylcholine group has strong electrostatic and hydration abilities, which reduces the number of salt ions with crystallization activity in the solution, thereby increasing the saturation concentration of the salt solution, playing a role in inhibiting crystallization, and further reducing the salt crystallization stress. In the present invention, APTS-POSS grafted on the PMH side chain is a group with strong adhesion ability, and the siloxane on it can form chemical bonds with sandstone cultural relics. In addition, polar chemical bonds such as amino and hydroxyl groups in the material structure also have strong adhesion abilities, which can significantly increase the structural strength of stone cultural relics and weaken the damage caused by salt crystallization during the desalination process. A calcium carbonate oligomer in the present invention synergistically enhances an amphoteric ion polymer material with APTS-POSS to form a dynamic organic-inorganic hybrid composite network. After this organic-inorganic composite network penetrates into the interior of sandstone, the unreacted siloxane in the POSS side chain and the calcium carbonate oligomer can react with components such as silicate in the sandstone cultural relics, so that the material is tightly bonded to the sandstone, causing the water-soluble PMH to be connected to the sandstone, extending the action time of PMH during the desalination process, and avoiding the loss of the material due to natural rainfall or water erosion.

[0022] To make the above objects, features and advantages of the present invention more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for use in the description of the specific embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Schematic diagram showing the principle of protecting sandstone by a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS according to the drip infiltration method.

[0025] Figure 2 Schematic diagram showing the principle of promoting sandstone desalination by a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS according to the plastering method.

[0026] Figure 3Schematic diagram of the protection effect of a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS on sandstone by the drop infiltration method in Example 1. Among them, a is the desalination rate diagram of sandstone after the calcium carbonate oligomer synergistically enhancing the amphoteric ion polymer material with APTS-POSS protects the sandstone in the form of hanging drop infiltration, and b is the statistical chart of the sand content in the salt crystal shell collected after the calcium carbonate oligomer synergistically enhancing the amphoteric ion polymer material with APTS-POSS protects the sandstone in the form of hanging drop infiltration.

[0027] Figure 4 Effect diagram showing the desalination of pulp synergistically with pulp by a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS from Example 1 to Example 3. In the figure caption, 0.5wt%, 1.0wt%, and 2.0wt% represent the mass fraction of the material in the pulp. Detailed implementation manners

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] Example 1

[0030] A preparation method of a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS, comprising:

[0031] Step 1: Using methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) as reaction monomers, ethanol as a solvent, and azobisisobutyronitrile (AIBN) as an initiator. After mixing, carry out a free radical polymerization reaction by stirring at 70°C. Concentrate the reaction product by rotary evaporation and precipitate and purify it with petroleum ether. Dry the solid obtained after precipitation and purification to obtain an amphoteric ion polymer P(MPC-ran-HEMA), named PMH. Dissolve PMH in ethanol to obtain an amphoteric ion polymer solution;

[0032] Among them, the total mass concentration of methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) is 2wt%, and the molar ratio of methacryloyloxyethyl phosphorylcholine to 2-hydroxyethyl methacrylate is 3:1.

[0033] Step 2: Prepare an ethanol solution of calcium chloride. After adding the capping agent triethylamine (TEA), stir well to mix evenly. Then slowly introduce CO2 gas. After the reaction ends, introduce CO2 gas for a period of time to obtain a dispersion of calcium carbonate oligomers. Purify the dispersion of calcium carbonate oligomers by centrifugation to obtain a calcium carbonate oligomer solution.

[0034] Specifically, the concentration of calcium chloride is 2.7 g / L, the addition amount of TEA is 6.5 wt%, the ventilation time of carbon dioxide is 0.5 h. During this process, the solution will experience a process from clear to turbid and then gradually become clear again. After the clarity of the solution no longer changes, introduce carbon dioxide for another 0.5 h. The centrifugation rate is 5500 rad / min, and the time is 5 min. During the centrifugation and ultrasonic dispersion processes, the temperature should be maintained between 15°C and 25°C. The mass fraction of the calcium carbonate oligomer solution is 0.10 wt%, and it should be stored refrigerated.

[0035] Step 3: Dissolve γ-glycidyletheroxysilylpropyl sesquisiloxane (EP-POSS) and 3-aminopropyltriethoxysilane (APTS) in ethanol and heat-react for 8 h to obtain an ethanol solution of APTS-POSS.

[0036] Among them, the total mass concentration of the γ-glycidyletheroxysilylpropyl sesquisiloxane and 3-aminopropyltriethoxysilane is 5 wt%, and the molar ratio of the γ-glycidyletheroxysilylpropyl sesquisiloxane to 3-aminopropyltriethoxysilane is 4:3; the reaction heating temperature is 48°C.

[0037] Step 4: Blend the ethanol solution of APTS-POSS, the zwitterionic polymer solution, and the calcium carbonate oligomer solution. The hydroxyl groups on the polymer side chain condense with the POSS-APTS siloxane, and the calcium carbonate oligomers replace TEA for capping agent replacement, thereby obtaining an ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material POSS-PMH / CaCO3.

[0038] Specifically, the total mass fraction of the solutes in the blended solution is 1.0 wt%. Among them, PMH accounts for about 33 wt% of the total solutes, the oligomeric calcium carbonate accounts for about 10 wt% of the mass of PMH, and APTS-POSS accounts for about 67 wt% of the total solutes.

[0039] Use the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example to protect sandstone cultural relics. There are two protection methods:

[0040] The first protection method is as follows:

[0041] The ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example was used to protect the sandstone cultural relics by the method of hanging-drop infiltration.

[0042] The second protection method is as follows:

[0043] First, the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example was mixed evenly with the pulp. After adding, the material content was about 0.5 wt% of the pulp mass. Subsequently, the solvent added in excess was evaporated to obtain desalted pulp.

[0044] Next, the obtained desalted pulp was applied to the upper surface of the sandstone cultural relic to be protected, and the thickness of the pulp application was about 1.5 cm.

[0045] Finally, water was sprayed onto the desalted pulp in the form of water mist every 6 h to 12 h to keep the pulp moist, so as to accelerate the desalination rate of the sandstone cultural relics.

[0046] After the protection was completed, the protection effect of this example was tested:

[0047] Wax sealing refers to a method of evenly brushing the heated and melted paraffin liquid onto the side surface of the stone body to block the migration of water and salt on this surface. For the sandstone protected by the first method, the wax sealing treatment should be carried out after the ethanol to be infiltrated into the sandstone cultural relics has completely volatilized; for the sandstone protected by the second method, the wax sealing treatment should be carried out before the pulp application. The wax-sealed sandstone cultural relics were inserted into a 0.5 mol / L sodium chloride solution to simulate the actual desalination process, and the desalination effect of the material was evaluated.

[0048] Figure 3Evaluation diagram of the anti-salt weathering effect of sandstone protected by a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material by the method of drop infiltration. Light gray represents unprotected sandstone, and black represents sandstone protected by the solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material with a mass fraction of 1.0 wt% prepared in this example. Among them, a is the desalination rate diagram of sandstone protected by a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material by the method of drop infiltration. It can be seen that the desalination masses at the 6th, 11th, 17th, and 22nd days are 0.070 g, 0.145 g, 0.167 g, and 0.185 g respectively, all higher than the desalination masses of unprotected sandstone, which are 0.045 g, 0.105 g, 0.172 g, and 0.145 g, proving that applying the material to drop infiltration has the effect of enhancing the desalination rate of sandstone cultural relics; b is the statistical chart of the sand content in the salt crystal crust collected after sandstone is protected by a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material by the method of drop infiltration. It can be seen that except for the 17th day, the sand contents at the 6th, 11th, and 22nd days are 0.0114 g, 0.0089 g, and 0.0057 g respectively, all lower than the sand contents of unprotected sandstone, which are 0.0341 g, 0.0111 g, and 0.0098 g, proving that applying the material to drop infiltration has the effect of strengthening sandstone cultural relics after. Figure 4 Desalination effect diagram of sandstone protected by a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material by the method of combining with pulp. In the figure, white represents the mass of soluble salts collected by the pulp after the pulp without mixed material is applied to the sandstone, and light gray represents the mass of soluble salts collected by the pulp after the pulp prepared in this example is applied to the sandstone. It can be seen that the masses of crystalline salts collected by the pulp prepared in this example at the 5th, 7th, 10th, and 13th days are 0.100 g, 0.162 g, 0.313 g, and 0.509 g respectively, all greater than the masses of crystalline salts collected by the pulp without mixed material, which are 0.040 g, 0.109 g, 0.208 g, and 0.285 g, proving that applying this material to desalination pulp also has the effect of enhancing the desalination rate of sandstone cultural relics.

[0049] Example 2

[0050] A preparation method of a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material, including:

[0051] Step 1: Using 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) as reaction monomers, ethanol as the solvent, and azobisisobutyronitrile (AIBN) as the initiator, after mixing, stir at 70 °C for free radical polymerization reaction. Concentrate the reaction product by rotary evaporation and precipitate and purify it with petroleum ether. Dry the solid obtained after precipitation and purification to obtain the zwitterionic polymer P(MPC-ran-HEMA), which is named PMH. Dissolve PMH in ethanol to obtain a zwitterionic polymer solution;

[0052] Among them, the total mass concentration of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) is 3 wt%, and the molar ratio of 2-methacryloyloxyethyl phosphorylcholine to 2-hydroxyethyl methacrylate is 3:1.

[0053] Step 2: Prepare an ethanol solution of calcium chloride, add the capping agent triethylamine (TEA), and stir well to make it evenly mixed. Then slowly introduce CO2 gas. After the reaction is completed, introduce CO2 gas for a period of time to obtain a dispersion of calcium carbonate oligomers. Purify the dispersion of calcium carbonate oligomers by centrifugation to obtain a calcium carbonate oligomer solution;

[0054] Specifically, the concentration of calcium chloride is 3.3 g / L, the addition amount of TEA is 5.0 wt%, the ventilation time of carbon dioxide is 0.5 h. During this process, the solution will experience a process from clear to turbid and then gradually become clear. After the clarity of the solution no longer changes, introduce carbon dioxide for another 0.5 h; the centrifugation rate is 5000 rad / min, the time is 6.0 min, and during the centrifugation and ultrasonic dispersion processes, it should be maintained between 15 °C and 25 °C. The mass fraction of the calcium carbonate oligomer solution is 0.10 wt%, and it should be stored refrigerated.

[0055] Step 3: Dissolve γ-glycidoxypropyl heptaisobutyl polyhedral oligomeric silsesquioxane (EP-POSS) and 3-aminopropyltriethoxysilane (APTS) in ethanol, and heat and react for 8 h to obtain an ethanol solution of APTS-POSS.

[0056] Among them, the total mass concentration of the γ-glycidoxypropyl heptaisobutyl polyhedral oligomeric silsesquioxane and 3-aminopropyltriethoxysilane is 5 wt%, and the molar ratio of the γ-glycidoxypropyl heptaisobutyl polyhedral oligomeric silsesquioxane to 3-aminopropyltriethoxysilane is 4:3; the reaction heating temperature is 46 °C.

[0057] Step 4: Blend the ethanol solution of APTS-POSS, the zwitterionic polymer solution, and the calcium carbonate oligomer solution. The hydroxyl groups on the polymer side chains condense with the POSS-APTS siloxane, and the calcium carbonate oligomer replaces TEA as the capping agent for displacement, thereby obtaining an ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material POSS-PMH / CaCO3.

[0058] Specifically, the total mass fraction of the solutes in the blended solution is 2 wt%, among which PMH accounts for about 33 wt% of the total solutes, the oligomeric calcium carbonate accounts for about 10 wt% of the mass of PMH, and APTS-POSS accounts for about 67 wt% of the total solutes.

[0059] The calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example is used to protect sandstone cultural relics. There are two protection methods:

[0060] The first protection method is as follows:

[0061] Use the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example to protect the sandstone cultural relics by the method of dropwise infiltration.

[0062] The second protection method is as follows:

[0063] First, mix the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example with pulp. The content of the added material is about 1.0 wt% of the mass of the pulp. Then, evaporate the excess added solvent to obtain desalted pulp.

[0064] Next, apply the obtained desalted pulp to the upper surface of the sandstone cultural relic to be protected. The thickness of the pulp application is about 1.5 cm.

[0065] Finally, spray water on the desalted pulp in the form of water mist every 6 h - 12 h to keep the pulp moist, thereby accelerating the desalination rate of the sandstone cultural relic.

[0066] For the sandstone protected by the first method, the wax sealing treatment should be carried out after the ethanol that has penetrated into the sandstone cultural relic has completely volatilized; for the sandstone protected by the second method, the wax sealing treatment should be carried out before the pulp is applied. Insert the wax-sealed sandstone cultural relic into a 0.5 mol / L sodium chloride solution to simulate the actual desalination process and evaluate the desalination effect of the material.

[0067] After the protection is completed, the protection effect of this example is inspected:

[0068] Figure 3It is an evaluation diagram of the anti-salt weathering effect of sandstone protected by a method of dripping penetration using a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS. Light gray represents unprotected sandstone, and black represents sandstone protected by a solution of a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with a mass fraction of 1.0 wt% prepared in this example. Among them, a is a desalination rate diagram of sandstone protected by a method of dripping penetration using a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS. It can be seen that the desalination masses at the 6th, 11th, 17th, and 22nd days are 0.088 g, 0.185 g, 0.223 g, and 0.253 g respectively, all higher than the desalination masses of unprotected sandstone, which are 0.045 g, 0.105 g, 0.172 g, and 0.145 g, proving that applying the material to dripping penetration has the effect of enhancing the desalination rate of sandstone cultural relics; b is a statistical chart of the sand content in the salt crystal crust collected after sandstone is protected by a method of dripping penetration using a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with APTS-POSS. It can be seen that except for the 17th day, the sand contents at the 6th, 11th, and 22nd days are 0.0154 g, 0.0090 g, 0.0057 g, and 0.0066 g respectively, all lower than the sand contents of unprotected sandstone, which are 0.0341 g, 0.0111 g, 0.0067 g, and 0.0098 g, proving that applying the material to dripping penetration has the effect of strengthening the sandstone cultural relics after. Figure 4 It is a desalination effect diagram of sandstone protected by a method of combining a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material with pulp. In the figure, white represents the mass of soluble salts collected by the pulp after the pulp without the mixed material is applied to the sandstone, and light gray represents the mass of soluble salts collected by the pulp after the pulp prepared in this example is applied to the sandstone. It can be seen that the masses of crystalline salts collected by the pulp prepared in this example at the 5th, 7th, 10th, and 13th days are 0.235 g, 0.320 g, 0.560 g, and 0.756 g respectively, all greater than the masses of crystalline salts collected by the pulp without the mixed material, which are 0.040 g, 0.109 g, 0.208 g, and 0.285 g, proving that applying this material to the desalination pulp also has the effect of enhancing the desalination rate of sandstone cultural relics. And compared with the mass of salt crystals collected by the pulp with a material mass ratio of 0.5 wt% in Example 1, the mass of salt crystals collected by the pulp with a material mass ratio of 1.0 wt% in this example has all increased, indicating that the higher the material mass ratio, the stronger the desalination ability.

[0069] Example 3

[0070] A preparation method of a calcium carbonate oligomer synergistically enhancing an amphoteric ion polymer material, comprising:

[0071] Step 1: Using 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) as reaction monomers, ethanol as the solvent, and azobisisobutyronitrile (AIBN) as the initiator, after mixing, stir at 70 °C for free radical polymerization reaction. Concentrate the reaction product by rotary evaporation and precipitate and purify it with petroleum ether. Dry the solid obtained after precipitation and purification to obtain the zwitterionic polymer P(MPC-ran-HEMA), which is named PMH. Dissolve PMH in ethanol to obtain a zwitterionic polymer solution;

[0072] Among them, the total mass concentration of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) is 5 wt%, and the molar ratio of 2-methacryloyloxyethyl phosphorylcholine to 2-hydroxyethyl methacrylate is 3:1.

[0073] Step 2: Prepare an ethanol solution of calcium chloride, add the capping agent triethylamine (TEA), and stir well to make it evenly mixed. Then slowly introduce CO2 gas. After the reaction ends, introduce CO2 gas for a period of time to obtain a dispersion of calcium carbonate oligomers. Purify the dispersion of calcium carbonate oligomers by centrifugation to obtain a calcium carbonate oligomer solution;

[0074] Specifically, the concentration of calcium chloride is 3.3 g / L, the addition amount of TEA is 5.5 wt%, the ventilation time of carbon dioxide is 0.5 h. During this process, the solution will experience a process from clear to turbid and then gradually become clear again. After the clarity of the solution no longer changes, introduce CO2 for another 0.5 h; the centrifugation rate is 6500 rad / min, and the time is 4.5 min. During the centrifugation and ultrasonic dispersion processes, the temperature should be maintained between 15 °C and 25 °C. The mass fraction of the calcium carbonate oligomer solution is 0.10 wt%, and it should be stored refrigerated.

[0075] Step 3: Dissolve γ-glycidoxypropyl heptaisobutyl polyhedral oligomeric silsesquioxane (EP-POSS) and 3-aminopropyltriethoxysilane (APTS) in ethanol, and heat and react for 8 h to obtain an ethanol solution of APTS-POSS.

[0076] Among them, the total mass concentration of the γ-glycidoxypropyl heptaisobutyl polyhedral oligomeric silsesquioxane and 3-aminopropyltriethoxysilane is 6 wt%, and the molar ratio of the γ-glycidoxypropyl heptaisobutyl polyhedral oligomeric silsesquioxane to 3-aminopropyltriethoxysilane is 4:3; the reaction heating temperature is 46 °C.

[0077] Step 4: Blend the ethanol solution of APTS-POSS, the zwitterionic polymer solution, and the calcium carbonate oligomer solution. The hydroxyl groups on the polymer side chains condense with the POSS-APTS siloxane, and the calcium carbonate oligomer replaces TEA as the capping agent for displacement, thereby obtaining an ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material POSS-PMH / CaCO3.

[0078] Specifically, the total mass fraction of the solutes in the blended solution is 2 wt%, among which PMH accounts for approximately 33 wt% of the total solutes, the oligomeric calcium carbonate accounts for approximately 10 wt% of the mass of PMH, and APTS-POSS accounts for approximately 67 wt% of the total solutes.

[0079] The calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example is used to protect sandstone cultural relics. There are two protection methods:

[0080] The first protection method is as follows:

[0081] Use the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example to protect the sandstone cultural relics by the method of dropwise infiltration.

[0082] The second protection method is as follows:

[0083] First, mix the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example with pulp. After adding, the material content is approximately 2.0 wt% of the mass of the pulp. Subsequently, evaporate the excess added solvent to obtain desalted pulp.

[0084] Then, apply the obtained desalted pulp to the upper surface of the sandstone cultural relic to be protected. The thickness of the pulp application is approximately 1.5 cm.

[0085] Finally, spray water on the desalted pulp in the form of a water mist every 6 h to 12 h to keep the pulp moist, thereby accelerating the desalination rate of the sandstone cultural relic.

[0086] For the sandstone protected by the first method, the wax sealing treatment should be carried out after the ethanol in the sandstone cultural relic to be infiltrated has completely volatilized; for the sandstone protected by the second method, the wax sealing treatment should be carried out before the pulp application. Insert the wax-sealed sandstone cultural relic into a 0.5 mol / L sodium chloride solution to simulate the actual desalination process and evaluate the desalination effect of the material.

[0087] After the protection is completed, the protection effect of this example is inspected:

[0088] The experimental results obtained by osmosis in this example are similar to those in Example 2. The desalination rate of the sandstone protected by this material is significantly higher than that of the unprotected sandstone, and the sand content in the salt crystallization crust is less than that of the unprotected sandstone, proving that the material has both the functions of strengthening the structure of stone cultural relics and enhancing the desalination rate. The experimental results of co-desalination with pulp are shown as Figure 4 shown, Figure 4 is the desalination effect diagram of sandstone protected by a method of combining a calcium carbonate oligomer and APTS-POSS enhanced zwitterionic polymer material with pulp. In the figure, white represents the mass of soluble salts collected by the pulp after the pulp without the mixed material is applied to the sandstone, and light gray represents the mass of soluble salts collected by the pulp after the pulp prepared in this example is applied to the sandstone. It can be seen that the masses of crystalline salts collected by the pulp prepared in this example on the 5th, 7th, 10th, and 13th days are 0.311 g, 0.381 g, 0.664 g, and 1.033 g respectively, all greater than the masses of crystalline salts collected by the pulp without the mixed material, which are 0.040 g, 0.109 g, 0.208 g, and 0.285 g. This proves that the application of this material to the desalination pulp also has the effect of enhancing the desalination rate of sandstone cultural relics. Moreover, compared with the mass of salt crystals collected by the pulp with a material mass ratio of 1.0 wt% in Example 1, the mass of salt crystals collected by the pulp with a material mass ratio of 2.0 wt% in this example has increased, indicating that the higher the material mass ratio, the stronger the desalination ability.

[0089] Example 4

[0090] A preparation method of a calcium carbonate oligomer and APTS-POSS enhanced zwitterionic polymer material, comprising:

[0091] Step 1, using methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) as reaction monomers, ethanol as a solvent, and azobisisobutyronitrile (AIBN) as an initiator. After mixing, stir at 65 °C for a free radical polymerization reaction. Concentrate the reaction product by rotary evaporation and precipitate and purify it with petroleum ether. Dry the solid after precipitation and purification to obtain a zwitterionic polymer P(MPC-ran-HEMA), which is named PMH. Dissolve PMH in ethanol to obtain a zwitterionic polymer solution;

[0092] Among them, the total mass concentration of methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) is 1 wt%, and the molar ratio of methacryloyloxyethyl phosphorylcholine to 2-hydroxyethyl methacrylate is 1:1.

[0093] Step 2: Prepare an ethanol solution of calcium chloride, add the capping agent triethylamine (TEA), and stir well to mix evenly. Then, slowly introduce CO2 gas. After the reaction ends, introduce CO2 gas for a period of time to obtain a dispersion of calcium carbonate oligomers. Purify the dispersion of calcium carbonate oligomers by centrifugation to obtain a calcium carbonate oligomer solution.

[0094] Specifically, the concentration of calcium chloride is 3.0 g / L, the addition amount of TEA is 4.5 wt%, and the ventilation time of carbon dioxide is 0.5 h. During this process, the solution will experience a process from clear to turbid and then gradually become clear again. After the clarity of the solution no longer changes, introduce carbon dioxide for another 0.5 h. The centrifugation rate is 5000 rad / min, and the time is 6.5 min. During the centrifugation and ultrasonic dispersion processes, the temperature should be maintained between 15°C and 25°C. The mass fraction of the calcium carbonate oligomer solution is 0.15 wt%, and it should be stored refrigerated.

[0095] Step 3: Dissolve γ-glycidoxypropylsilsesquioxane (EP-POSS) and 3-aminopropyltriethoxysilane (APTS) in ethanol and heat-react for 8 h to obtain an ethanol solution of APTS-POSS.

[0096] Among them, the total mass concentration of γ-glycidoxypropylsilsesquioxane and 3-aminopropyltriethoxysilane is 3 wt%, and the molar ratio of γ-glycidoxypropylsilsesquioxane to 3-aminopropyltriethoxysilane is 4:3; the reaction heating temperature is 49°C.

[0097] Step 4: Blend the ethanol solution of APTS-POSS, the zwitterionic polymer solution, and the calcium carbonate oligomer solution. The hydroxyl groups on the polymer side chain undergo condensation with POSS-APTS siloxane, and the calcium carbonate oligomer replaces TEA for capping agent replacement, thereby obtaining an ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material POSS-PMH / CaCO3.

[0098] Specifically, the total mass fraction of the solutes in the blended solution is 1 wt%. Among them, PMH accounts for about 20 wt% of the total amount of solutes, oligomeric calcium carbonate accounts for about 15 wt% of the mass of PMH, and APTS-POSS accounts for about 80 wt% of the total amount of solutes.

[0099] The calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained by this example is used to protect sandstone cultural relics. There are two protection methods:

[0100] The first protection method is as follows:

[0101] The ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example was used to protect the sandstone cultural relics by means of hanging-drop infiltration.

[0102] The second protection method is as follows:

[0103] First, the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example was mixed evenly with the pulp. After adding, the material content was about 0.5 wt% of the pulp mass. Subsequently, the solvent added in excess was evaporated to obtain desalted pulp.

[0104] Next, the obtained desalted pulp was applied to the upper surface of the sandstone cultural relic to be protected, and the thickness of the pulp application was about 1.5 cm.

[0105] Finally, water was sprayed onto the desalted pulp in the form of water mist every 6 h to 12 h to keep the pulp moist, thereby accelerating the desalination rate of the sandstone cultural relics.

[0106] Example 5

[0107] A preparation method of a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material includes:

[0108] Step 1: Using methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) as reaction monomers, ethanol as a solvent, and azobisisobutyronitrile (AIBN) as an initiator, after mixing, stirring was carried out at 75 °C for free radical polymerization reaction. The reaction product was concentrated by rotary evaporation and precipitated and purified using petroleum ether. The solid after precipitation and purification was dried to obtain a zwitterionic polymer P(MPC-ran-HEMA), which was named PMH. PMH was dissolved in ethanol to obtain a zwitterionic polymer solution;

[0109] Among them, the total mass concentration of methacryloyloxyethyl phosphorylcholine (MPC) and 2-hydroxyethyl methacrylate (HEMA) was 2 wt%, and the molar ratio of methacryloyloxyethyl phosphorylcholine to 2-hydroxyethyl methacrylate was 2:1.

[0110] Step 2: Prepare an ethanol solution of calcium chloride, add the capping agent triethylamine (TEA), and stir well to make it mix evenly. Then, slowly introduce CO2 gas. After the reaction ends, introduce CO2 gas for a period of time to obtain a dispersion of calcium carbonate oligomers. The dispersion of calcium carbonate oligomers was purified by centrifugation to obtain a calcium carbonate oligomer solution;

[0111] Specifically, the concentration of calcium chloride is 3.0 g / L, the addition amount of TEA is 5 wt%, the aeration time of carbon dioxide is 0.5 h. During this process, the solution will experience a process from clear to turbid and then gradually become clear again. After the clarity of the solution no longer changes, carbon dioxide is aerated for another 0.5 h; the centrifugation rate is 5500 rad / min, the time is 5 min, and the temperature should be maintained between 15°C and 25°C during centrifugation and ultrasonic dispersion. The mass fraction of the calcium carbonate oligomer solution is 0.05 wt%, and it should be stored refrigerated.

[0112] Step 3: Dissolve γ-glycidoxypropylsilsesquioxane (EP-POSS) and 3-aminopropyltriethoxysilane (APTS) in ethanol and heat react for 8 h to obtain an ethanol solution of APTS-POSS.

[0113] Among them, the total mass concentration of the γ-glycidoxypropylsilsesquioxane and 3-aminopropyltriethoxysilane is 1 wt%, and the molar ratio of the γ-glycidoxypropylsilsesquioxane to 3-aminopropyltriethoxysilane is 4:3;

[0114] Among them, the heating temperature of the reaction is 50°C.

[0115] Step 4: Blend the ethanol solution of APTS-POSS, the zwitterionic polymer solution and the calcium carbonate oligomer solution. The hydroxyl groups on the polymer side chain condense with the POSS-APTS siloxane, and the calcium carbonate oligomer replaces TEA for end-capping agent replacement, thereby obtaining an ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material POSS-PMH / CaCO3.

[0116] Specifically, the total mass fraction of the solutes in the blended solution is 5 wt%. Among them, PMH accounts for about 80 wt% of the total solutes, oligomeric calcium carbonate accounts for about 5 wt% of the mass of PMH, and APTS-POSS accounts for about 20 wt% of the total solutes.

[0117] The calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained by this example is used to protect sandstone cultural relics. There are two protection methods:

[0118] The first protection method is as follows:

[0119] Use the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained by this example to protect the sandstone cultural relics in the form of hanging drop penetration.

[0120] The second protection method is as follows:

[0121] First, mix the ethanol solution of the calcium carbonate oligomer synergistically enhanced zwitterionic polymer material obtained in this example with the pulp. After adding, the material content is about 1.0 wt% of the pulp mass. Subsequently, evaporate the excess added solvent to obtain desalted pulp.

[0122] Next, apply the obtained desalted pulp to the upper surface of the sandstone cultural relic to be protected. The thickness of the pulp application is about 1.5 cm.

[0123] Finally, spray water on the desalted pulp in the form of water mist every 6 h to 12 h to keep the pulp moist, thereby accelerating the desalination rate of the sandstone cultural relic.

[0124] The phosphorylcholine groups on the PMH side chain can cap the calcium carbonate oligomer by hydrogen bonding and ion interaction to replace TEA. The ethoxysilane on the APTS-POSS chain can undergo a siloxane condensation reaction with the hydroxyl groups on the PMH side chain, and this reaction can be carried out at room temperature. These two effects enable a calcium carbonate oligomer synergistically enhanced zwitterionic polymer material to form a dynamic organic-inorganic hybrid composite network. After the organic-inorganic composite network penetrates into the interior of the sandstone, the unreacted siloxane on the POSS side chain and the calcium carbonate oligomer can react with components such as silicate in the sandstone cultural relic, so that the material is tightly bonded to the sandstone, causing the water-soluble PMH to be connected to the sandstone, extending the action time of PMH in the desalination process, and preventing the material from losing its function due to natural rainfall or water erosion.

[0125] Finally, it should be noted that the above-mentioned embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions recorded in the foregoing embodiments or easily conceive of changes, or make equivalent replacements for some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A preparation method of a zwitterionic polymer material enhanced by calcium carbonate oligomers and APTS-POSS, characterized in that, Comprising: Using methacryloyloxyethyl phosphorylcholine and 2-hydroxyethyl methacrylate as reaction monomers to carry out free radical polymerization reaction, purifying and drying the reaction product and dissolving it in an organic solvent to obtain an amphoteric ion polymer solution; Dissolving γ-glycidoxypropyl octasilsesquioxane and 3-aminopropyltriethoxysilane in an organic solvent, heating and reacting to obtain an APTS-POSS solution; Blending the calcium carbonate oligomer solution, the amphoteric ion polymer solution and the APTS-POSS solution to obtain a blended solution, and the blended solution is the calcium carbonate oligomer synergistic APTS-POSS enhanced amphoteric ion polymer material.

2. The preparation method of a zwitterionic polymer material enhanced by calcium carbonate oligomer and APTS-POSS according to claim 1, characterized in that, The total mass fraction of the solutes in the blended solution is 1 wt% to 5 wt%, wherein the calcium carbonate oligomer accounts for 5 wt% to 15 wt% of the mass of the amphoteric ion polymer, and APTS-POSS accounts for 20 wt% to 80 wt% of the total mass of the solutes.

3. The preparation method of a zwitterionic polymer material enhanced by calcium carbonate oligomer and APTS-POSS according to claim 1, characterized in that The total mass concentration of the methacryloyloxyethyl phosphorylcholine and the 2-hydroxyethyl methacrylate is 1 wt% to 5 wt%, and the molar ratio of the methacryloyloxyethyl phosphorylcholine to the 2-hydroxyethyl methacrylate is 3:1 to 1:

1.

4. The preparation method of a zwitterionic polymer material enhanced by calcium carbonate oligomer and APTS-POSS according to claim 1, wherein The temperature during the free radical polymerization reaction is 65°C to 75°C.

5. The preparation method of a zwitterionic polymer material enhanced by calcium carbonate oligomer and APTS-POSS according to claim 1, characterized in that, The total mass concentration of the γ-glycidoxypropyl octasilsesquioxane and the 3-aminopropyltriethoxysilane is 1 wt% to 6 wt%, and the molar ratio of the γ-glycidoxypropyl octasilsesquioxane to the 3-aminopropyltriethoxysilane is 4:

3.

6. The preparation method of a zwitterionic polymer material enhanced by calcium carbonate oligomer and APTS-POSS according to claim 1, characterized in that, When preparing the APTS-POSS solution, the heating temperature is 46°C to 50°C.

7. The preparation method of a zwitterionic polymer material enhanced by calcium carbonate oligomer and APTS-POSS according to claim 1, wherein, The mass fraction of the calcium carbonate oligomer solution is 0.10 wt% to 0.35 wt%.

8. A calcium carbonate oligomer synergistically enhances zwitterionic polymer materials with APTS-POSS, characterized in that, Prepared by the preparation method according to any one of claims 1 to 7.

9. The application of a calcium carbonate oligomer in synergistically enhancing an amphoteric ion polymer material with APTS-POSS as claimed in claim 8, wherein, Suspending and infiltrating the calcium carbonate oligomer synergistic APTS-POSS enhanced amphoteric ion polymer material into the sandstone cultural relics to be protected to protect the sandstone cultural relics.

10. The application of a calcium carbonate oligomer in synergistically enhancing zwitterionic polymer materials with APTS-POSS as claimed in claim 8, characterized in that, Mixing the calcium carbonate oligomer synergistic APTS-POSS enhanced amphoteric ion polymer material with pulp to obtain desalinated pulp; Applying the desalinated pulp to the surface of the sandstone cultural relics to be protected, and spraying water on the desalinated pulp in the form of water mist every 6 h to 12 h to protect the sandstone cultural relics.

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