Calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection and preparation method thereof

Abstract

The invention discloses sandstone cultural relics protection calcium carbonate oligomer strengthening siloxane oligomer modified hyperbranched polyester polyol solution and preparation method, including: esterification is carried out after the trimethylolpropane and 2,2-dimethylolpropionic acid of melting are mixed, after question response is completed, reaction product is purified, and hyperbranched polyester polyol is obtained; The hyperbranched polyester polyol is dissolved in an organic solvent to obtain a hyperbranched polyester polyol solution, after the hyperbranched polyester polyol solution is mixed with a siloxane oligomer solution, stirring to solution clarity is obtained, and the hyperbranched polyester polyol solution modified by siloxane oligomer is obtained; After calcium carbonate oligomer solution is mixed with the hyperbranched polyester polyol solution modified by the siloxane oligomer, stirring to solution clarity is obtained, and calcium carbonate oligomer strengthening siloxane oligomer modified hyperbranched polyester polyol solution is obtained. The present invention improves the resistance to wet heat aging after bonding strength and sandstone bonding.

Description

Technical Field

[0001] The invention belongs to the technical field of bonding and reinforcing materials for sandstone cave cultural relics, and particularly relates to a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for protecting sandstone cultural relics and a preparation method thereof. Background Art

[0002] my country's sandstone grottoes and stone carvings are numerous, large-scale, and widely distributed, demonstrating the infinite charm of civilization. However, most sandstones are felsic sandstones, which are not inherently strong. Under the influence of natural environmental factors, most sandstone cultural relics have developed surface pits, surface powdering, lamellar exfoliation, and local hollowing, among other weathering phenomena. In response to natural factors such as water / salt migration, crystallized salt precipitation, and dry-wet cycles that cause lamellar exfoliation, surface sandification, warping, cracking, and hollowing in sandstone grottoes, the applicant, in previous research on the preparation and performance of bonding reinforcement materials, proposed a calcium carbonate oligomer-enhanced siloxane-modified polyvinyl alcohol solution for the protection of sandstone cultural relics. Although silicone has been used to modify polyvinyl alcohol and improve the environmental stability of interfacial bonding, polyvinyl alcohol has poor water resistance and heat resistance, and its bonding strength will drop significantly under hot and humid conditions. Therefore, it is urgent to find new materials to improve the resistance to hot and humid aging after bonding with sandstone. Summary of the Invention

[0003] In response to the problems existing in the prior art, the present invention provides a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection and a preparation method, which improves the bonding strength and the moisture-heat aging resistance of the sandstone after bonding.

[0004] In order to solve the above technical problems, the present invention is implemented through the following technical solutions:

[0005] A method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection, comprising:

[0006] Mixing molten trimethylolpropane and 2,2-dimethylolpropionic acid and performing an esterification reaction, and after the reaction is completed, purifying the reaction product to obtain a hyperbranched polyester polyol;

[0007] Dissolving the hyperbranched polyester polyol in an organic solvent to obtain a hyperbranched polyester polyol solution, mixing the hyperbranched polyester polyol solution with a siloxane oligomer solution and stirring until the solution is clear and transparent, to obtain a siloxane oligomer-modified hyperbranched polyester polyol solution;

[0008] The calcium carbonate oligomer solution is mixed with the siloxane oligomer modified hyperbranched polyester polyol solution and stirred until the solution becomes clear and transparent to obtain a calcium carbonate oligomer reinforced siloxane oligomer modified hyperbranched polyester polyol solution.

[0009] Furthermore, the molar ratio of the trimethylolpropane to the 2,2-dimethylolpropionic acid is 1:(6-9), and the temperature of the esterification reaction is 140° C. to 170° C.

[0010] Furthermore, the mass fraction of the hyperbranched polyester polyol is 5wt% to 20wt%, the mass fraction of the siloxane oligomer is 8wt% to 11wt%, and the mass fraction of the hyperbranched polyester polyol modified by the siloxane oligomer is 10.00wt% to 15.5wt%.

[0011] Furthermore, the mass fraction of the calcium carbonate oligomer is 0.11 wt% to 0.33 wt%, and the mass fraction of the calcium carbonate oligomer-reinforced silicone oligomer-modified hyperbranched polyester polyol is 6.70 wt% to 10.41 wt%.

[0012] Furthermore, the preparation method of the siloxane oligomer solution includes:

[0013] Tetramethyl orthosilicate and dimethyldimethoxysiloxane are dissolved in anhydrous ethanol and stirred to obtain the siloxane oligomer solution.

[0014] Furthermore, the mass fraction of the tetramethyl orthosilicate is 4.00 wt% to 6.00 wt%, and the mass fraction of the dimethyldimethoxysiloxane is 3.00 wt% to 5.00 wt%.

[0015] A calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection is prepared by adopting the preparation method.

[0016] The invention discloses an application of a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection, which is used as an adhesive or reinforcing agent in the bonding and reinforcement protection of sandstone cultural relics.

[0017] Furthermore, the calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution is infiltrated into the weathered surface of the sandstone cultural relic by a drop coating method to perform penetration reinforcement protection.

[0018] Furthermore, a grouting reinforcement method is used to mix the calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution with sandstone cultural relic powder to form a slurry mixture, and the slurry mixture is poured into the interlayer cracks and / or hollows of the sandstone cultural relic for bonding and reinforcement protection.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] The present invention provides a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection. The hyperbranched polyester polyol has a spherical molecular structure and contains more C═O and —OH functional groups. Compared with polyvinyl alcohol, the hyperbranched polyester polyol has weaker intramolecular hydrogen bonding and smaller cohesive force. Therefore, the hyperbranched polyester polyol can be better cross-linked with silane oligomers and calcium carbonate oligomers through hydrogen bonding and coordination bonding, significantly improving the bonding performance and thermal stability of the hybrid material and significantly improving the moisture-heat aging resistance of the interface-reinforced sandstone. Specifically, hyperbranched polyester polyols have fewer intramolecular interactions and stronger intermolecular interactions. Based on the unique structure of hyperbranched polyester polyols, they are used to replace polyvinyl alcohol and blended with silicone oligomers and calcium carbonate oligomers to prepare calcium carbonate oligomer-reinforced silicone oligomer-modified hyperbranched polyester polyol hybrid materials. The resulting new hybrid materials can protect sandstone caves in outdoor water / salt environments and under conditions of frequent changes in temperature and humidity, further reducing the penetration, erosion and destruction of water and salt, and avoiding flaking, surface sandification, warping and cracking, and hollowing diseases.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the specific embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Schematic diagram of the preparation process of calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol of the present invention;

[0024] Figure 2 Schematic diagram of the chemical reaction principle in the formation process of calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol of the present invention;

[0025] Figure 3 This is a comparison chart of the aging cycle and sandstone weight change rate after the three hybrid materials were used to reinforce Binxian sandstone. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] Example 1

[0028] The method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection comprises the following steps:

[0029] Step 1: 1.34g TMP monomer (trimethylolpropane) is added to a four-mouth round-bottomed reaction flask equipped with an agitator, reflux condenser, thermometer, and nitrogen inlet. After preheating until TMP is completely melted, 10.73g DMPA monomer (2,2-dimethylolpropionic acid) and 0.17g PTSA catalyst are added and the reaction is heated to 140°C for a sufficient reaction. During the reaction, stirring speed is accelerated, and the byproduct water generated is removed by increasing the flow rate of nitrogen and vacuuming. The pH value of the reactants is tracked to track the reaction degree of the carboxyl group. When the pH remains substantially unchanged, the reaction is terminated and the molten product is directly poured out from the round-bottomed reaction flask to obtain a pale yellow crude product. The pale yellow crude product is wrapped with qualitative filter paper, washed with n-hexane through a Soxhlet extractor until colorless, and then dissolved in acetone to obtain a hyperbranched polyester polyol solution.

[0030] Step 2: dissolving tetramethyl orthosilicate and dimethyldimethoxysiloxane in anhydrous ethanol solvent to obtain a siloxane oligomer solution; wherein the mass fraction of tetramethyl orthosilicate is 6.00 wt %, the mass fraction of dimethyldimethoxysiloxane is 3.00 wt %, and the mass fraction of the siloxane oligomer is 9.00 wt %.

[0031] Step 3: Mixing the hyperbranched polyester polyol solution of step 1 with the siloxane oligomer solution obtained in step 2 and stirring until the solution is clear and transparent to obtain a siloxane oligomer-modified hyperbranched polyester polyol solution, wherein the mass fraction of the hyperbranched polyester polyol is 5 wt %, and the mass fraction of the siloxane oligomer-modified hyperbranched polyester polyol is 12.5 wt %.

[0032] Step 4: Dissolve 0.11 g of anhydrous calcium chloride in anhydrous ethanol, add triethylamine as a capping agent, and introduce carbon dioxide gas. When the solution changes from turbid to translucent, an amorphous calcium carbonate solution is obtained. Then, stir and centrifuge to discard the supernatant, add ethanol, and sonicate to obtain a calcium carbonate oligomer solution.

[0033] Step 5: Mixing the calcium carbonate oligomer solution obtained in step 4 and the siloxane oligomer-modified hyperbranched polyester polyol solution obtained in step 3, and stirring until the solution becomes clear and transparent, to obtain a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution. The calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution comprises 0.11 wt % of calcium carbonate oligomer and 8.04 wt % of calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol.

[0034] Example 2

[0035] The method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection comprises the following steps:

[0036] Step 1: Add 1.34g of TMP monomer to a four-necked round-bottomed reaction flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen inlet. Preheat until the TMP is completely melted, then add 8.05g of DMPA monomer and 0.34g of PTSA catalyst. Raise the temperature to 130°C for complete reaction. During the reaction, increase the stirring speed, remove the generated water byproduct by increasing the nitrogen flow rate and vacuuming, and simultaneously monitor the pH of the reactants to track the extent of carboxyl group reaction. Terminate the reaction when the pH remains essentially unchanged, and pour the molten product directly from the round-bottomed reaction flask to obtain a pale yellow crude product. Wrap the pale yellow crude product with qualitative filter paper, wash with n-hexane using a Soxhlet extractor until colorless, and dissolve in acetone to obtain a hyperbranched polyester polyol solution.

[0037] Step 2: dissolving tetramethyl orthosilicate and dimethyldimethoxysiloxane in anhydrous ethanol solvent to obtain a siloxane oligomer solution; wherein the mass fraction of tetramethyl orthosilicate is 4.00 wt %, the mass fraction of dimethyldimethoxysiloxane is 4.00 wt %, and the mass fraction of the siloxane oligomer is 8.00 wt %.

[0038] Step 3: Mixing the hyperbranched polyester polyol solution of step 1 with the siloxane oligomer solution obtained in step 2 and stirring until the solution is clear and transparent to obtain a siloxane oligomer-modified hyperbranched polyester polyol solution, wherein the mass fraction of the hyperbranched polyester polyol is 15 wt %, and the mass fraction of the siloxane oligomer-modified hyperbranched polyester polyol is 11.5 wt %.

[0039] Step 4: Dissolve 0.33 g of anhydrous calcium chloride in anhydrous ethanol, add triethylamine as a capping agent, and introduce carbon dioxide gas. When the solution changes from turbid to translucent, an amorphous calcium carbonate solution is obtained. Then, stir and centrifuge to discard the supernatant, add ethanol, and sonicate to obtain a calcium carbonate oligomer solution.

[0040] Step 5: Mix the calcium carbonate oligomer solution obtained in step 4 and the siloxane oligomer-modified hyperbranched polyester polyol solution obtained in step 3 and stir until the solution becomes clear and transparent to obtain a calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol solution. The mass fraction of the calcium carbonate oligomer is 0.33 wt%, and the mass fraction of the calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol is 7.77 wt%.

[0041] Example 3

[0042] The method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection comprises the following steps:

[0043] Step 1: Add 1.34g of TMP monomer to a four-necked round-bottomed reaction flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen inlet. Preheat until the TMP is completely melted. Then, add 9.39g of DMPA monomer and 0.26g of PTSA catalyst. Heat to 170°C and allow to react thoroughly. During the reaction, increase the stirring speed. Remove the generated water byproduct by increasing the nitrogen flow rate and applying vacuum. Simultaneously, monitor the pH of the reactants to track the extent of carboxyl group reaction. Terminate the reaction when the pH remains essentially unchanged. Discard the molten product directly from the round-bottomed reaction flask to obtain a pale yellow crude product. Wrap the pale yellow crude product with qualitative filter paper, wash with n-hexane using a Soxhlet extractor until colorless, and dissolve in acetone to obtain a hyperbranched polyester polyol solution.

[0044] Step 2: dissolving tetramethyl orthosilicate and dimethyldimethoxysiloxane in anhydrous ethanol solvent to obtain a siloxane oligomer solution; wherein the mass fraction of tetramethyl orthosilicate is 5.00 wt %, the mass fraction of dimethyldimethoxysiloxane is 5.00 wt %, and the mass fraction of the siloxane oligomer is 10.00 wt %.

[0045] Step 3: Mixing the hyperbranched polyester polyol solution of step 1 with the siloxane oligomer solution obtained in step 2 and stirring until the solution is clear and transparent to obtain a siloxane oligomer-modified hyperbranched polyester polyol solution, wherein the mass fraction of the hyperbranched polyester polyol is 10 wt %, and the mass fraction of the siloxane oligomer-modified hyperbranched polyester polyol is 10 wt %.

[0046] Step 4: Dissolve 0.11 g of anhydrous calcium chloride in anhydrous ethanol, add triethylamine as a capping agent, and introduce carbon dioxide gas. When the solution changes from turbid to translucent, an amorphous calcium carbonate solution is obtained. Then, stir and centrifuge to discard the supernatant, add ethanol, and sonicate to obtain a calcium carbonate oligomer solution.

[0047] Step 5: Mix the calcium carbonate oligomer solution obtained in step 4 and the siloxane oligomer-modified hyperbranched polyester polyol solution obtained in step 3 and stir until the solution becomes clear and transparent to obtain a calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol solution. The mass fraction of the calcium carbonate oligomer is 0.11 wt%, and the mass fraction of the calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol is 6.70 wt%.

[0048] Example 4

[0049] The method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection comprises the following steps:

[0050] Step 1: Add 1.34g of TMP monomer to a four-necked round-bottomed reaction flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen inlet. Preheat until the TMP is completely melted. Then, add 12.07g of DMPA monomer and 0.52g of PTSA catalyst. Heat to 150°C and allow to react thoroughly. During the reaction, increase the stirring speed. Remove the generated water byproduct by increasing the nitrogen flow rate and applying vacuum. Simultaneously, monitor the pH of the reactants to track the extent of carboxyl group reaction. Terminate the reaction when the pH remains essentially unchanged. Discard the molten product directly from the round-bottomed reaction flask to obtain a pale yellow crude product. Wrap the pale yellow crude product with qualitative filter paper, wash with n-hexane using a Soxhlet extractor until colorless, and dissolve in acetone to obtain a hyperbranched polyester polyol solution.

[0051] Step 2: dissolving tetramethyl orthosilicate and dimethyldimethoxysiloxane in anhydrous ethanol solvent to obtain a siloxane oligomer solution; wherein the mass fraction of tetramethyl orthosilicate is 6.00 wt %, the mass fraction of dimethyldimethoxysiloxane is 5.00 wt %, and the mass fraction of the siloxane oligomer is 11.00 wt %.

[0052] Step 3: Mixing the hyperbranched polyester polyol solution of step 1 with the siloxane oligomer solution obtained in step 2 and stirring until the solution is clear and transparent to obtain a siloxane oligomer-modified hyperbranched polyester polyol solution, wherein the mass fraction of the hyperbranched polyester polyol is 20.00 wt % and the mass fraction of the siloxane oligomer-modified hyperbranched polyester polyol is 15.50 wt %.

[0053] Step 4: Dissolve 0.22 g of anhydrous calcium chloride in anhydrous ethanol, add triethylamine as a capping agent, and introduce carbon dioxide gas. When the solution changes from turbid to translucent, an amorphous calcium carbonate solution is obtained. Then, stir and centrifuge to discard the supernatant, add ethanol, and sonicate to obtain a calcium carbonate oligomer solution.

[0054] Step 5: Mixing the calcium carbonate oligomer solution obtained in step 4 and the siloxane oligomer-modified hyperbranched polyester polyol solution obtained in step 3, and stirring until the solution becomes clear and transparent, to obtain a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution. The calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution comprises 0.22 wt % of calcium carbonate oligomer and 10.41 wt % of calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol.

[0055] The calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution obtained in this example was used to bond and reinforce the Leshan Giant Buddha Temple Grottoes. The specific application method is as follows:

[0056] First, the dried and ready-to-use ancient sandstone sample of Leshan Giant Buddha Temple was crushed and ground into fine sand powder, and then the dispersions of three protective materials, namely, calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol, 3.53wt% calcium carbonate oligomer-reinforced siloxane oligomer-modified polyvinyl alcohol hybrid material, and 10wt% siloxane oligomer-modified polyvinyl alcohol, were mixed with fine sand. The resulting blended slurry was applied to the cross-section of the ancient sandstone sample, and then placed in a fume hood at room temperature to dry for 24 hours, and then placed in a drying oven at 55°C to dry to constant weight. Finally, it was taken out and placed in a desiccator for use. The protected sandstone and blank sandstone were dried and stored for use.

[0057] The three types of protected sandstone treated in the experiment were subjected to salt-heat aging cycle test. Figure 3 As shown, the standard for the mass change of the protected sandstone is 50%, with a mass change exceeding 50% indicating material failure. The results show that after thirteen cycles of hydrothermal aging, the mass change of the siloxane-modified polyvinyl alcohol exceeds 50%, indicating material failure. At this point, the mass loss rates of the calcium carbonate oligomer-siloxane-modified polyvinyl alcohol and the calcium carbonate oligomer-siloxane-modified hyperbranched polyester polyol are 25% and 15%, respectively, indicating that both hybrid materials still exhibit good hydrothermal aging resistance and interfacial adhesion. After sixteen cycles of hydrothermal aging, the mass loss of the calcium carbonate oligomer-siloxane-modified polyvinyl alcohol reaches 50%, indicating material failure, while the mass loss of the calcium carbonate oligomer-siloxane-modified hyperbranched polyester polyol is 18%. Therefore, it can be shown that the hydrothermal cycling resistance of sandstone protected by the calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol material is significantly improved.

[0058] The present invention uses calcium carbonate oligomers to enhance siloxane-modified hyperbranched polyester polyols. To address the hollowing, cracking and falling phenomena of sandstone, a grouting bonding method is used to bond the damaged interface of the sandstone to achieve the purpose of protection. For the weathered sandstone layer, a titration penetration method is used to infiltrate the protective material into the weathered sandstone layer for reinforcement, thereby further improving the bonding strength and the moisture-heat aging resistance of the sandstone after bonding.

[0059] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relic protection, characterized in that: include: Mixing molten trimethylolpropane and 2,2-dimethylolpropionic acid and performing an esterification reaction, and after the reaction is completed, purifying the reaction product to obtain a hyperbranched polyester polyol; Dissolving the hyperbranched polyester polyol in an organic solvent to obtain a hyperbranched polyester polyol solution, mixing the hyperbranched polyester polyol solution with a siloxane oligomer solution and stirring until the solution is clear and transparent, to obtain a siloxane oligomer-modified hyperbranched polyester polyol solution; The calcium carbonate oligomer solution is mixed with the siloxane oligomer modified hyperbranched polyester polyol solution and stirred until the solution becomes clear and transparent to obtain a calcium carbonate oligomer reinforced siloxane oligomer modified hyperbranched polyester polyol solution.

2. The method for preparing a calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 1, characterized in that: The molar ratio of the trimethylolpropane to the 2,2-dimethylolpropionic acid is 1:(6-9), and the temperature of the esterification reaction is 140° C. to 170° C.

3. The method for preparing a calcium carbonate oligomer-enhanced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 1, characterized in that: The mass fraction of the hyperbranched polyester polyol is 5 wt % to 20 wt %, the mass fraction of the siloxane oligomer is 8 wt % to 11 wt %, and the mass fraction of the hyperbranched polyester polyol modified by the siloxane oligomer is 10.00 wt % to 15.5 wt %.

4. The method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 3, characterized in that: The mass fraction of the calcium carbonate oligomer is 0.11 wt% to 0.33 wt%, and the mass fraction of the calcium carbonate oligomer-reinforced silicone oligomer-modified hyperbranched polyester polyol is 6.70 wt% to 10.41 wt%.

5. The method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 1, characterized in that: The preparation method of the siloxane oligomer solution comprises: Tetramethyl orthosilicate and dimethyldimethoxysiloxane are dissolved in anhydrous ethanol and stirred to obtain the siloxane oligomer solution.

6. The method for preparing a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 5, characterized in that: The mass fraction of the tetramethyl orthosilicate is 4.00 wt% to 6.00 wt%, and the mass fraction of the dimethyldimethoxysiloxane is 3.00 wt% to 5.00 wt%.

7. A calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection, characterized in that: The method is prepared according to any one of claims 1 to 6.

8. The use of a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 7, characterized in that: It is used as an adhesive or reinforcing agent in the bonding, reinforcement and protection of sandstone cultural relics.

9. The use of a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 8, characterized in that: The calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution is infiltrated into the weathered surface of the sandstone cultural relic by a drop coating method to perform penetration reinforcement protection.

10. The use of a calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution for sandstone cultural relics protection according to claim 8, characterized in that: The calcium carbonate oligomer-reinforced siloxane oligomer-modified hyperbranched polyester polyol solution is mixed with sandstone cultural relic powder by a grouting reinforcement method to form a slurry mixture, which is then poured into interlayer cracks and / or hollows of the sandstone cultural relic for bonding, reinforcement and protection.

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