CN113121148B

CN113121148B - Foam stabilizer and preparation method and application thereof

Info

Publication number: CN113121148B
Application number: CN201911400332.8A
Authority: CN
Inventors: 单广程; 陈健; 吴井志; 高南箫; 乔敏; 朱伯淞; 冉千平; 洪锦祥
Original assignee: Sobute New Materials Co Ltd; Bote New Materials Taizhou Jiangyan Co Ltd
Current assignee: Sobute New Materials Co Ltd; Bote New Materials Taizhou Jiangyan Co Ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2022-06-14
Anticipated expiration: 2039-12-30
Also published as: CN113121148A

Abstract

The invention discloses a foam stabilizer based on a slow release technology, and a preparation method and application thereof. The foam stabilizer based on the slow release technology consists of an amphiphilic side chain connected with an ester bond and a cyclodextrin structure core; 18-24 amphiphilic side chains are arranged; the amphiphilic side chain consists of a hydrophobic chain segment and a hydrophilic unit, wherein the hydrophobic chain segment consists of an aromatic ring structure and 2-6 propylene oxide units, and the hydrophilic unit is 2-10 ethylene oxide units; and hydrolyzing the ester bond under an alkaline condition, and hydrolyzing the amphiphilic side chain into 18-24 air entraining agent molecules. The foam stabilizer based on the slow release technology is slowly hydrolyzed under an alkaline condition to release an air entraining agent; therefore, the defect of quick foam loss of the existing air entraining agent is overcome, the air entraining agent has excellent effect of stabilizing the air content of concrete, and meanwhile, the hardening strength of the concrete cannot be greatly influenced.

Description

Foam stabilizer and preparation method and application thereof

Technical Field

The invention belongs to the field of building materials, and particularly relates to a foam stabilizer and a preparation method thereof.

Background

The modern concrete has great changes in the aspects of raw material composition, performance, process and the like, and the modern concrete technology represented by improving the fineness of cement and introducing the fifth component of industrial waste residue and the sixth component of chemical admixture leads a slurry system to be more complicated and has more prominent durability problem.

The durability of the concrete is closely related to the quality of air holes, the structure of the air holes is determined by the concrete air entraining agent, but due to the influence of salt ions and adsorption, the air bubbles introduced by the air entraining agent have short survival time and are easy to break, and the freeze thawing resistance, the durability and the like of the concrete are influenced. Therefore, in practical engineering, a concrete foam stabilizer which does not affect the initial air content needs to be added on the basis of the original air entraining agent in some cases, so as to make up for the problem of air content reduction caused by air bubble destruction in the later period.

The foam stabilizer is a surfactant like the air entraining agent, and can be directionally arranged on a gas-liquid interface through hydrophobic association between hydrophobic chains, so that the surface tension of an aqueous solution is remarkably reduced, the strength of a surface film of a bubble is enhanced, and the stability of the foam cement slurry is improved.

The prior art mainly achieves better effects of air entraining and foam stabilizing by improving some traditional air entraining agent structures.

Patent document CN108250204A discloses a gemini surfactant containing 2 hydrophobic segments and 2 hydrophilic units, which has excellent air-entraining and foam-stabilizing properties and does not have a great influence on the hardening strength of concrete when used as an air-entraining agent for concrete.

Patent document CN106431052A reports that a foam stabilizer composition contains C6-C10 alkylamide alkyl amine oxide, C6-C20 alkylamide alkyl betaine and triterpenoid saponin compounds, and is used in the field of oil and gas well cementation engineering, can help to form foam cement slurry with higher foam stability, and has lower density, low permeability and high compressive strength.

The existing concrete foam stabilizer synthesis patents are all used for directly improving the structure of the air entraining agent, mainly focus on good initial air entraining performance, but the air content loss of the concrete after a period of time is large; while some compounding methods may damage the stability between the components in improving air-entraining and foam-stabilizing properties and may also affect the hardening strength of the concrete.

Disclosure of Invention

The loss of bubbles introduced by the existing air entraining agent is too fast, and the direct compound use of the existing foam stabilizer and the air entraining agent can cause the damage to the stability among components or the influence on the hardening strength of concrete; aiming at the problems, the invention provides a foam stabilizer based on a sustained-release technology, and a preparation method and application thereof.

The foam stabilizer based on the slow release technology is used for emitting an air entraining agent under the alkaline condition; therefore, the defect of quick loss of air bubbles of the existing air entraining agent is overcome, the air entraining agent has excellent effect of stabilizing the air content of concrete, and meanwhile, the hardening strength of the concrete cannot be greatly influenced.

The foam stabilizer based on the slow release technology consists of an amphiphilic side chain connected with an ester bond and a cyclodextrin structure core; 18-24 amphiphilic side chains are arranged; the amphiphilic side chain consists of a hydrophobic chain segment and a hydrophilic unit, wherein the hydrophobic chain segment consists of an aromatic ring structure and 2-6 propylene oxide units, and the hydrophilic unit is 2-10 ethylene oxide units; and hydrolyzing the ester bond under an alkaline condition, and hydrolyzing the amphiphilic side chain into 18-24 air entraining agent molecules.

The aromatic ring structure is selected from any one of naphthyl, phenanthryl, anthryl, pyrenyl and benzopyrenyl.

The hydrolyzed air entraining agent molecule contains an aromatic ring structure, 2-6 epoxypropane hydrophobic chain segments and 2-10 hydrophilic units of ethylene oxide and carboxylic acid groups; because the air-entraining agent molecules are slowly hydrolyzed, the concentration of the air-entraining agent is improved in the later stage of concrete mixing, and the performance index of efficiently stabilizing the air content of the concrete is achieved. And the large aromatic ring structure contained in the molecular structure of the air entraining agent generated by hydrolysis has strong pi-pi accumulation effect, so that the molecules are arranged more closely and orderly at a gas-liquid interface, thereby playing a foam stabilizing effect.

The concrete foam stabilizer based on the slow release technology is obtained by polymerizing hydroxy polycyclic aromatic hydrocarbon with propylene oxide and ethylene oxide and then reacting with cyclodextrin. The molar ratio of hydroxyl groups in the cyclodextrin to the hydroxy polycyclic aromatic hydrocarbon is (0.95-1.05): 1.

the hydroxy polycyclic aromatic hydrocarbon is any one of hydroxy naphthalene, hydroxy anthracene, hydroxy phenanthrene, hydroxy pyrene and hydroxy benzopyrene.

The cyclodextrin is one of alpha-cyclodextrin, beta-cyclodextrin and gamma-cyclodextrin.

The structural general formula of the high-efficiency foam stabilizer is shown as follows:

wherein m is an integer of 2 to 6, n is an integer of 1 to 9, and s is 6,7 or 8.

The preparation method of the concrete foam stabilizer based on the slow release technology comprises the steps of firstly polymerizing hydroxy polycyclic aromatic hydrocarbon and propylene oxide under the action of a catalyst I to generate an intermediate A, continuously polymerizing the intermediate A and ethylene oxide to generate an intermediate B, oxidizing the intermediate B by a strong oxidant to obtain an intermediate C, and reacting the intermediate C with cyclodextrin under the action of a catalyst II to generate a concrete foam stabilizer product D based on the slow release technology.

The catalyst I is one of sodium methoxide, sodium hydroxide, potassium hydroxide and sodium ethoxide, and the dosage of the catalyst I is 1.05-1.20 times of the molar weight of the hydroxy polycyclic aromatic hydrocarbon.

The catalyst I is preferably sodium methoxide.

The oxidant is one of potassium permanganate and sodium hypochlorite; the dosage of the intermediate B is 1.0-1.5 times of the molar weight of the intermediate B.

The catalyst II is one of sodium p-toluenesulfonate, 4-dimethylaminopyridine/N, N' -dicyclohexylcarbodiimide (DMAP/DCC) and 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS); the dosage is 1.05 to 1.5 times of the molar weight of the intermediate C.

The invention relates to a preparation method of a concrete foam stabilizer based on a slow release technology, which specifically comprises the following steps:

(1) putting hydroxyl polycyclic aromatic hydrocarbon into a reaction kettle, adding a catalyst I under the action of a protective atmosphere, heating to 100-160 ℃, slowly introducing propylene oxide, reacting for 1-3 hours to obtain an intermediate A, continuously introducing ethylene oxide slowly, reacting for 1-3 hours, cooling to below 100 ℃, neutralizing, filtering and purifying to obtain an intermediate B.

(2) And putting the intermediate B into a reactor, adding an oxidant, stirring and heating, heating to 110-130 ℃, and reacting for 1-2 hours to obtain an intermediate C.

(3) Dissolving the intermediate C in an organic solvent, putting the organic solvent into a reaction kettle with a reflux water separator, adding a catalyst II, heating to 140-180 ℃, slowly adding cyclodextrin, heating for refluxing, reacting for 3-5 hours, stopping heating for refluxing, cooling to 50 ℃, distilling to remove the solvent, filtering a crude product, washing with ethanol, and drying to obtain the concrete foam stabilizer product D based on the slow release technology.

The neutralization and purification steps in the step (1) are as follows: adjusting the pH value of the solution to 6-7, extracting with dichloromethane, drying with anhydrous sodium sulfate, filtering and distilling to obtain an intermediate B;

the organic solvent in the step (3) is N, N-Dimethylformamide (DMF), and the mass percentage concentration of the intermediate C after being dissolved in the organic solvent is 5-50%;

the preparation method of the concrete foam stabilizer based on the slow release technology comprises the following synthetic route:

the concrete foam stabilizer based on the slow release technology can be used in combination with various additives such as a concrete water reducing agent, an air entraining agent, a retarder, an antifreezing agent, a shrinkage reducing agent and the like, and has good compatibility.

The recommended folding and fixing mixing amount of the novel concrete foam stabilizer is 0.01-0.04 ten-thousandth of the using amount of cement in concrete. The foam stabilizing effect is not good when the amount of the additive is less than the required amount, and unnecessary waste is caused when the amount of the additive is more than the required amount.

Drawings

FIG. 1 is a graph showing the loss of gas content in concrete according to examples and comparative examples.

Detailed Description

The following examples, which are set forth in more detail to describe the preparation of concrete foam stabilizers based on the slow release technique according to the method of the present invention and are given by way of illustration only, are intended to enable one skilled in the art to understand the contents of the present invention and to practice it accordingly, and are not intended to limit the scope of the present invention in any way. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

In the application embodiment of the invention, all reactors are provided with a thermometer, a stirrer and an inert gas inlet, and are cleaned and dried for standby before use.

Synthesis example 1

Putting 1.0mol of hydroxypyrene into a reaction kettle, adding 1.1mol of sodium methoxide under the action of protective atmosphere, heating to 130 ℃, slowly introducing 4.0mol of propylene oxide, stirring for reaction for 2 hours, continuously and slowly introducing 8.0mol of ethylene oxide, continuously reacting for 2 hours, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by using hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And putting 1.0mol of dried intermediate B into a reactor, adding 1.2mol of potassium permanganate, stirring and heating, heating to 120 ℃, and reacting for 2 hours to obtain an intermediate C.

Dissolving 1.0mol of the intermediate C in 50ml of DMF, putting into a reaction kettle with a reflux water separator, adding 1.3mol of p-toluenesulfonic acid, heating to 160 ℃, slowly adding 0.14mol of beta-cyclodextrin, heating for reflux, taking out water generated by the reaction from the water separator, reacting for 4 hours, stopping heating for reflux, cooling to 50 ℃, distilling to remove the solvent, obtaining a crude product, filtering, washing with ethanol, and drying to obtain a final product.

Synthesis example 2

Putting 1.0mol of hydroxynaphthalene into a reaction kettle, adding 1.05mol of sodium hydroxide under the action of protective atmosphere, heating to 110 ℃, slowly introducing 2.0mol of propylene oxide, stirring for reaction for 1.5h, continuously and slowly introducing 4.0mol of ethylene oxide, continuously reacting for 1.5h, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by using hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And then putting 1.0mol of dried intermediate B into a reactor, adding 1.1mol of sodium hypochlorite, stirring and heating, heating to 110 ℃, and reacting for 1.5h to obtain intermediate C.

Dissolving 1.0mol of the intermediate C in 40ml of DMF, putting into a reaction kettle with a reflux splitter, adding 1.1mol of p-toluenesulfonic acid, heating to 140 ℃, slowly adding 0.167mol of alpha-cyclodextrin, heating for reflux, taking out water generated in the reaction from the water splitter, reacting for 3 hours, stopping heating for reflux, cooling to 50 ℃, distilling to remove the solvent, filtering, washing with ethanol, and drying to obtain the final product.

Synthesis example 3

Putting 1.0mol of hydroxyl phenanthrene into a reaction kettle, adding 1.2mol of potassium hydroxide under the action of protective atmosphere, heating to 120 ℃, slowly introducing 3.0mol of propylene oxide, stirring for reaction for 1.0h, continuously and slowly introducing 6.0mol of ethylene oxide, continuously reacting for 1.0h, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by using hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And then putting 1.0mol of dried intermediate B into a reactor, adding 1.3mol of sodium hypochlorite, stirring and heating, heating to 130 ℃, and reacting for 1.0h to obtain intermediate C.

Dissolving 1.0mol of the intermediate C in 60ml of DMF, putting into a reaction kettle with a reflux water separator, adding 1.05mol of p-toluenesulfonic acid, heating to 150 ℃, slowly adding 0.13mol of gamma-cyclodextrin, heating for reflux, taking out water generated by the reaction from the water separator, reacting for 5 hours, stopping heating for reflux, cooling to 50 ℃, distilling to remove the solvent, obtaining a crude product, filtering, washing with ethanol, and drying to obtain a final product.

Synthesis example 4

Putting 1.0mol of hydroxyanthracene into a reaction kettle, adding 1.15mol of sodium ethoxide under the action of protective atmosphere, heating to 160 ℃, slowly introducing 5.0mol of epoxypropane, stirring for reaction for 2.5h, continuously and slowly introducing 5.0mol of ethylene oxide, continuously reacting for 2.5h, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by using hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And putting 1.0mol of dried intermediate B into a reactor, adding 1.5mol of potassium permanganate, stirring and heating, heating to 125 ℃, and reacting for 2.0h to obtain intermediate C.

Dissolving 1.0mol of the intermediate C in 40ml of DMF, putting into a reaction kettle with a reflux water separator, adding 1.2mol of DMAP and 1.3mol of DCC, heating to 170 ℃, slowly adding 0.158mol of alpha-cyclodextrin, heating and refluxing, taking out water generated in the reaction from the water separator, reacting for 4.5 hours, stopping heating and refluxing, cooling to 50 ℃, distilling to remove the solvent, filtering, washing with ethanol, and drying to obtain a final product.

Synthesis example 5

Putting 1.0mol of hydroxybenzpyrene into a reaction kettle, adding 1.2mol of sodium methoxide under the action of protective atmosphere, heating to 150 ℃, slowly introducing 6.0mol of propylene oxide, stirring for reaction for 3 hours, continuously and slowly introducing 10.0mol of ethylene oxide, continuously reacting for 3.0 hours, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And then putting 1.0mol of dried intermediate B into a reactor, adding 1.0mol of sodium hypochlorite, stirring and heating, heating to 115 ℃, and reacting for 1.5h to obtain an intermediate C.

Dissolving 1.0mol of the intermediate C in 50ml of DMF, putting into a reaction kettle with a reflux splitter, adding 1.5mol of EDC and 1.4mol of NHS, heating to 180 ℃, slowly adding 0.146mol of beta-cyclodextrin, heating and refluxing, taking out water generated by the reaction from the water separator, reacting for 3.5h, stopping heating and refluxing, cooling to 50 ℃, distilling to remove the solvent, filtering, washing with ethanol, and drying to obtain a final product.

Synthesis comparative example 1

Putting 1.0mol of hydroxypyrene into a reaction kettle, adding 1.1mol of sodium methoxide under the action of protective atmosphere, heating to 130 ℃, slowly introducing 8.0mol of ethylene oxide, continuously reacting for 2h, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by using hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And putting 1.0mol of dried intermediate B into a reactor, adding 1.2mol of potassium permanganate, stirring and heating, heating to 120 ℃, and reacting for 2 hours to obtain an intermediate C.

Dissolving 1.0mol of the intermediate C in 50ml of DMF, putting into a reaction kettle with a reflux splitter, adding 1.3mol of p-toluenesulfonic acid, heating to 160 ℃, slowly adding 0.14mol of beta-cyclodextrin, heating for reflux, taking out water generated by the reaction from the water splitter, reacting for 4 hours, stopping heating for reflux, cooling to 50 ℃, distilling to remove the solvent, filtering, washing with ethanol, and drying to obtain the final product.

Synthesis comparative example 2

Putting 1.0mol of hydroxypyrene into a reaction kettle, adding 1.1mol of sodium methoxide under the action of protective atmosphere, heating to 130 ℃, slowly introducing 4.0mol of propylene oxide, stirring for reacting for 2 hours, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by using hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And putting 1.0mol of dried intermediate B into a reactor, adding 1.2mol of potassium permanganate, stirring and heating, heating to 120 ℃, and reacting for 2 hours to obtain an intermediate C.

Synthesis comparative example 3

Putting 1.0mol of hydroxypyrene into a reaction kettle, adding 1.2mol of potassium permanganate, stirring and heating, heating to 120 ℃, and reacting for 2 hours to obtain an intermediate C.

Synthesis comparative example 4

Putting 1.0mol of hydroxypyrene into a reaction kettle, adding 1.1mol of sodium methoxide under the action of protective atmosphere, heating to 130 ℃, slowly introducing 4.0mol of propylene oxide, stirring for reaction for 2 hours, continuously and slowly introducing 8.0mol of ethylene oxide, continuously reacting for 2 hours, cooling to below 100 ℃, adjusting the pH of the solution to 6-7 by using hydrochloric acid, extracting by using 50mL of dichloromethane, drying by using anhydrous sodium sulfate, filtering, and distilling to obtain a long-chain alcohol intermediate B. And putting the dried 1.0mol of intermediate B into a reactor, adding 1.2mol of potassium permanganate, stirring and heating, heating to 120 ℃, reacting for 2 hours to obtain a crude product, filtering, washing with ethanol, and drying to obtain a final product.

Application examples

The concrete test piece is subjected to concrete gas content and strength test by the foam stabilizer obtained in the synthesis embodiment according to the relevant regulations of national standard GB8076-2008 concrete admixture, and a hardened pore structure analyzer is used for measuring the bubble structure and parameters of the corresponding concrete test piece. The concrete mix proportions used are shown in table 1:

TABLE 1 concrete mix proportion

Cement	Sand	Large stone	Small stone	Water (W)	Polycarboxylate water reducing agent/rubber material
						3.30kg	7.29kg	7.14kg	4.76kg	1.25kg	0.15wt％

The cement used is 52.5 R.P.II cement in small open field, the sand is medium sand with fineness modulus Mx of 2.6, and the pebbles are continuous graded broken stones with the grain size of 5-25 mm. The used polycarboxylic acid water reducing agent is provided by Jiangsu Subo new materials Co.Ltd, and the SDS air entraining agent is provided by the national pharmaceutical group chemical reagent Co.Ltd.

We compare the foam stabilizer of the present invention with a surfactant used in the foam stabilizer used in the examples and on the market. As the foam stabilizer does not bleed air initially, in order to investigate the high-efficiency foam stabilizing effect of the foam stabilizer, the foam stabilizer is used together with an SDS (sodium dodecyl sulfate) air-entraining agent with poor bubble stability, and under the condition of the same mixing amount of the air-entraining agent and the foam stabilizer, the retention amount of the air content after initial time and 1 hour is compared to further characterize the foam stabilizing effect of the foam stabilizer. The experimental results are shown in table 2, wherein blanks 1 and 2 refer to the comparative examples where only the water reducing agent and only the air entraining agent are added, respectively, and the following examples and comparative examples and the coconut oil diethanolamide sample are all mixed samples with the SDS air entraining agent.

TABLE 2 comparison of concrete Properties of the examples and comparative examples

As can be seen from table 2: the mixing amount of the foam stabilizer synthesized in all the examples and the comparative examples is controlled to be consistent, and the air content of the initial sample is basically the same, which indicates that the novel foam stabilizer does not bleed air initially; in terms of the air content loss after 1 hour, the blank 2 group is that the air content loss of the SDS air entraining agent is 2.9% greatly, but after the foam stabilizer product disclosed by the invention is doped, the air content loss after 1 hour is obviously reduced and is only 0.2-0.9%.

As can be seen from table 2, the average cell diameter and the cell pitch coefficient in the examples are also small, which is advantageous for the stabilization of the cells. In addition, compared with concrete strength data, the concrete foam stabilizer test block based on the slow release technology has the advantage that the 28-day strength of the test block is obviously higher than that of the test blocks of other four comparative samples and is obviously higher than that of a blank sample only added with the air entraining agent. The concrete foam stabilizer based on the slow release technology has high-efficiency foam stabilizing performance and has little influence on the strength of concrete.

FIG. 1 shows the loss of gas content in concrete for 1 hour in synthetic examples and comparative examples, and it can be seen from the figure that the gas content loss is in the order of example 1 < example 4 < example 3 < example 5 < example 2 < comparative example 1 < comparative example 2 < comparative example 3 < comparative example 4, and the gas content loss in comparative examples is larger than that in examples, because comparative examples 1,2 and 3 lack a propylene oxide unit, an ethylene oxide unit, a propylene oxide unit and an ethylene oxide unit respectively, so that only polyarylate and carboxyl are obtained after the ester bond hydrolysis of the foam stabilizer, and the obtained foam stabilizer is a common air-entraining structure, therefore, the foam stabilizer effect is weaker, and the gas content loss is 1.0-2.0%; comparative example 4 is not structurally esterified with cyclodextrin relative to the examples, and thus the structure itself is a highly efficient air entraining agent structure having pyrenyl and 4 hydrophobic segments of propylene oxide, 8 hydrophilic groups of ethylene oxide and carboxylic acid groups, and this comparative example is initially air entraining, and thus when used in combination with an SDS air entraining agent, it is equivalent to increasing the concentration of the air entraining agent to make the air content of the concrete greater, affecting the working performance of the concrete. The commercial sample was cocodiethanolamide with a greater loss of 2.7% gas content than in this example. Therefore, the novel foam stabilizer has the effect of stabilizing the air content of concrete more efficiently than the prior foam stabilizer under the condition of the same mixing amount.

Claims

1. The foam stabilizer is characterized by consisting of an amphipathic side chain connected by an ester bond and a cyclodextrin structure core; 18-24 amphiphilic side chains are arranged; the amphiphilic side chain consists of a hydrophobic chain segment and a hydrophilic unit, wherein the hydrophobic chain segment consists of an aromatic ring structure and 2-6 propylene oxide units, and the hydrophilic unit is 2-10 ethylene oxide units; hydrolyzing an ester bond under an alkaline condition, and hydrolyzing an amphiphilic side chain into 18-24 air entraining agent molecules;

the aromatic ring structure is selected from any one of naphthyl, phenanthryl, anthryl, pyrenyl and benzopyrenyl;

the structural general formula of the foam stabilizer is shown as follows:

2. The foam stabilizer according to claim 1, wherein the foam stabilizer is obtained by polymerizing hydroxy polycyclic aromatic hydrocarbon with propylene oxide and ethylene oxide, and then reacting with cyclodextrin; the molar ratio of hydroxyl groups in the cyclodextrin to the hydroxy polycyclic aromatic hydrocarbon is (0.95-1.05): 1.

3. the foam stabilizer according to claim 2, wherein the hydroxy polycyclic aromatic hydrocarbon is any one of hydroxy naphthalene, hydroxy anthracene, hydroxy phenanthrene, hydroxy pyrene and hydroxy benzopyrene.

4. The foam stabilizer of claim 2, wherein the cyclodextrin is one of α -cyclodextrin, β -cyclodextrin, and γ -cyclodextrin.

5. The preparation method of the foam stabilizer according to any one of claims 1 to 4, characterized in that firstly, hydroxy polycyclic aromatic hydrocarbon and propylene oxide are polymerized under the action of a catalyst I to generate an intermediate A, the intermediate A and ethylene oxide are continuously polymerized to generate an intermediate B, the intermediate B is oxidized by an oxidant to obtain an intermediate C, and the intermediate C is reacted with cyclodextrin under the action of a catalyst II to generate a foam stabilizer product D;

the catalyst I is one of sodium methoxide, sodium hydroxide, potassium hydroxide and sodium ethoxide, and the dosage of the catalyst I is 1.05-1.20 times of the molar weight of the hydroxy polycyclic aromatic hydrocarbon;

the oxidant is one of potassium permanganate and sodium hypochlorite; the dosage of the intermediate B is 1.0-1.5 times of the molar weight of the intermediate B;

6. The preparation method of the foam stabilizer according to claim 5, wherein the catalyst I is sodium methoxide.

7. The preparation method of the foam stabilizer according to claim 5 or 6, which is characterized by comprising the following steps:

(1) putting hydroxyl polycyclic aromatic hydrocarbon into a reaction kettle, adding a catalyst I under the action of a protective atmosphere, heating to 100-160 ℃, slowly introducing propylene oxide, reacting for 1-3 hours to obtain an intermediate A, continuously and slowly introducing ethylene oxide, reacting for 1-3 hours, cooling to below 100 ℃, neutralizing, filtering and purifying to obtain an intermediate B;

(2) putting the intermediate B into a reactor, adding an oxidant, stirring and heating, heating to 110-130 ℃, and reacting for 1-2 hours to obtain an intermediate C;

(3) dissolving the intermediate C in an organic solvent, putting the organic solvent into a reaction kettle with a reflux water separator, adding a catalyst II, heating to 140-180 ℃, slowly adding cyclodextrin, heating for refluxing, reacting for 3-5 hours, stopping heating for refluxing, cooling to 50 ℃, distilling to remove the solvent, filtering a crude product, washing with ethanol, and drying to obtain a foam stabilizer product D.

8. The preparation method of the foam stabilizer according to claim 7, wherein the neutralization, filtration and purification steps in the step (1) are as follows: and adjusting the pH value of the solution to 6-7, extracting with dichloromethane, drying with anhydrous sodium sulfate, filtering and distilling to obtain an intermediate B.

9. The preparation method of the foam stabilizer according to claim 7, wherein the organic solvent in the step (3) is N, N-Dimethylformamide (DMF), and the mass percentage concentration of the intermediate C after being dissolved in the organic solvent is 5-50%.