High-stability non-silicon defoamer and preparation method thereof

Abstract

The application discloses a high-stability non-silicon defoamer and a preparation method thereof, and relates to the technical field of defoamers. The high-stability non-silicon defoamer comprises the following raw materials in parts by weight: 15-25 parts of hydrogenated castor oil, 8-15 parts of perfluoropolyether carboxylic acid, 5-10 parts of fatty alcohol, 10-18 parts of fatty acid ester, 3-8 parts of a stabilizer, 4-10 parts of an emulsifier and 60-70 parts of deionized water. The stabilizer is prepared by the following steps: 2-(4-aminobenzene azo) benzoic acid is reacted with polytetrahydrofuran diol to obtain an intermediate 1, the intermediate 1 is reacted with 3-mercaptopropionic acid to obtain an intermediate 2, and the intermediate 2 is reacted with polyethylene glycol monomethyl ether. The high-stability non-silicon defoamer prepared by the application has good stability, rapid bubble breaking and long-lasting bubble suppressing capacity.

Description

Technical Field

[0001] This invention relates to the field of defoamer technology, specifically to a highly stable non-silicone defoamer and its preparation method. Background Technology

[0002] Defoamers, as key additives for controlling foam in industrial production, are widely used in papermaking, printing and dyeing, fermentation, petrochemicals, and other fields. Traditional defoamers are mainly divided into two categories: silicone-based and non-silicone-based. Silicone-based defoamers (such as polydimethylsiloxane) have high defoaming efficiency, but they have drawbacks such as easy residue of silicone spots, which can affect subsequent processes (such as coating and film forming). Non-silicone-based defoamers (such as fatty acid esters and polyethers) have good compatibility, but they generally face problems such as poor stability (emulsions are prone to separation and demulsification at high temperatures) and insufficient defoaming persistence (active components are easily lost), making it difficult to meet the modern industrial demand for long-cycle, high-stability defoaming.

[0003] Chinese invention patent CN119303348A discloses a non-silicone defoamer, its synthesis method, and its application in scandium extraction. This defoamer is synthesized from three components (A, B, and C) through a two-step reaction. The specific synthesis steps are: 1) an amino acid A reacts with a fatty alcohol B via esterification to generate an amino ester D; 2) the amino ester D reacts with a triazine compound C via substitution to obtain the non-silicone defoamer. This defoamer has a wide range of applications, suitable for front-end scandium extraction in laterite nickel ore hydrometallurgy and open-circuit scandium impurity processes in MHP hydrometallurgy. It is added as an additive during extraction to reduce liquid surface tension, prevent the formation and accumulation of third-phase substances, reduce emulsification, and improve process stability and product quality, thus possessing significant industrial application value. However, its dynamic stability is still insufficient, making it difficult to achieve stable long-term defoaming. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a highly stable non-silicone defoamer and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A highly stable non-silicone defoamer comprises the following raw materials in parts by weight: 15-25 parts hydrogenated castor oil, 8-15 parts perfluoropolyether carboxylic acid, 5-10 parts fatty alcohol, 10-18 parts fatty acid ester, 3-8 parts stabilizer, 4-10 parts emulsifier, and 60-70 parts water.

[0007] The stabilizer is prepared by the following method:

[0008] S1: Under nitrogen protection, 2-(4-aminophenylazo)benzoic acid, triethylamine and anhydrous DMF are mixed and then slowly added to an anhydrous DMF solution of 9-fluorenyl chloroformate. The mixture is stirred, and then polytetrahydrofurandiol, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine are added to give intermediate 1.

[0009] S2: Under nitrogen protection, 3-mercaptopropionic acid is mixed with anhydrous DMF, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide are added for activation; then intermediate 1 and triethylamine are slowly added to the DMF solution to react and obtain intermediate 2.

[0010] S3: Under nitrogen protection, intermediate 2, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite and anhydrous DMF are mixed, and polyethylene glycol monomethyl ether and p-toluenesulfonic acid are added to react and obtain the stabilizer.

[0011] In step S1, the mass ratio of polytetrahydrofuran diol to 2-(4-aminophenylazo)benzoic acid is 1:(0.5-0.55).

[0012] In step S2, the mass ratio of intermediate 1 to 3-mercaptopropionic acid is 1:(0.15-0.16).

[0013] In step S3, the mass ratio of intermediate 2 to polyethylene glycol monomethyl ether is 1:(2.5-2.7).

[0014] The reaction temperature in step S1 is 25-30℃, and the reaction time is 14-16h.

[0015] The reaction temperature in step S2 is 25-35℃, and the reaction time is 10-12h.

[0016] The reaction temperature in step S3 is 120-140℃, and the reaction time is 11-13h.

[0017] The hydrogenated castor oil is one of PEG-40 hydrogenated castor oil and PEG-60 hydrogenated castor oil.

[0018] The fatty alcohol is one of lauryl alcohol, cetyl alcohol, and stearyl alcohol; the fatty acid ester is one of glyceryl monooleate and sorbitan monostearate.

[0019] The emulsifier is epoxytriacetic acid ester.

[0020] A method for preparing a highly stable non-silicone defoamer includes the following steps:

[0021] (1) Weigh out the following by weight: 15-25 parts hydrogenated castor oil, 8-15 parts perfluoropolyether carboxylic acid, 5-10 parts fatty alcohol, 10-18 parts fatty acid ester, 3-8 parts stabilizer, 4-10 parts emulsifier, and 60-70 parts deionized water.

[0022] (2) Melt hydrogenated castor oil, add fatty alcohol and fatty acid ester, stir and mix well, add perfluoropolyether carboxylic acid, and shear at high speed to obtain oil phase; add emulsifier to water and sonicate to obtain aqueous phase; preheat aqueous phase, slowly drip oil phase into aqueous phase under high speed stirring, continue stirring after dripping, homogenize under high pressure 3 times, cool the homogenized emulsion, add stabilizer, stir and mix well, and defoam under vacuum to obtain high-stability non-silicone defoamer.

[0023] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0024] The stabilizer prepared in this invention comprises hydrophobic segments of polytetrahydrofuran glycol, azobenzene dynamic structures, and hydrophilic segments of polyethylene glycol monomethyl ether. It is an amphiphilic block stabilizer containing dynamic bonds, overcoming the limitations of static protection and achieving stable long-term defoaming, thus improving defoaming speed and foam suppression ability. The interfacial anchoring effect between the azobenzene dynamic bonds in its molecular structure and the block segments significantly enhances the stability, environmental tolerance, and defoaming and foam suppression capabilities of the defoamer. Detailed Implementation

[0025] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0026] Example 1: Preparation of stabilizer:

[0027] S1: Under nitrogen protection, 5g of 2-(4-aminophenylazo)benzoic acid and 3.4g of triethylamine were added to 100ml of anhydrous DMF and stirred until homogeneous. At 0℃, 30ml of anhydrous DMF solution containing 6.2g of fluorenyl chloroformate was slowly added dropwise (over 20min). The mixture was stirred at 25℃ for 12h. Then, 10g of polytetrahydrofuran glycol (number average molecular weight 1000), 2.6g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.02g of 4-dimethylaminopyridine were added. The mixture was stirred for 15min and reacted at 25℃ for 16h. The reaction solution was then poured into 300ml of an ice-water mixture (containing 15ml of 1M... In HCl, stir for 30 min to neutralize triethylamine; extract three times with ethyl acetate (150 ml each time), combine the organic phases and wash with 150 ml saturated brine, add 10 g anhydrous sodium sulfate and dry for 2 h, filter, concentrate under reduced pressure at 50 °C for 1 h to obtain a concentrate, add the concentrate to 50 ml of a mixed solution of DMF and piperidine (DMF to piperidine volume ratio of 4:1), stir at 25 °C for 35 min to deprotect, then add 400 ml of 0.5 M HCl solution at 0 °C, stir to precipitate, filter, wash successively with 100 ml cold water, 75 ml 5 wt% sodium bicarbonate solution, and 100 ml cold water, dry under vacuum at 40 °C for 12 h to obtain intermediate 1.

[0028]

[0029] S2: Under nitrogen protection, 1.5 g of 3-mercaptopropionic acid was mixed with 50 ml of anhydrous DMF. 3.8 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 2.3 g of N-hydroxysuccinimide were weighed and mixed, then added in two equal batches (5 min apart) to the 3-mercaptopropionic acid solution. The mixture was stirred and activated in an ice bath for 45 min. 10 g of intermediate 1 and 2 g of triethylamine were added to 50 ml of anhydrous DMF and stirred until homogeneous. The activated 3-mercaptopropionic acid solution was slowly added (dropwise over 20 min). The reaction was carried out at 25 °C for 12 h. The mixture was poured into 200 ml of ice water, filtered, and the filter cake was washed with deionized water (3 × 100 ml). The mixture was then subjected to silica gel column chromatography (eluent: dichloromethane / methanol). V / V The mixture (r=10:1) was purified and rotary evaporated at 65°C for 2 hours to obtain intermediate 2; the reaction equation is shown below:

[0030]

[0031] S3: Under nitrogen protection, 10 g of intermediate 2 and 0.2 g of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite were added to 150 ml of anhydrous DMF and stirred until homogeneous. Then, 25 g of polyethylene glycol monomethyl ether (number average molecular weight 2000) and 0.5 g of p-toluenesulfonic acid were added. The mixture was reacted at 120 °C for 13 h, cooled to room temperature, and 50 ml of saturated sodium bicarbonate solution was added and stirred for 30 min. After separation, the organic phase was retained and washed successively with 100 ml of deionized water and 100 ml of saturated brine. The mixture was dried over 10 g of anhydrous sodium sulfate for 2 h, filtered, and rotary evaporated at 60 °C for 3 h. The solution was dissolved in 100 ml of dichloromethane and subjected to silica gel column chromatography (eluent: petroleum ether / ethyl acetate). V / V The mixture of 5:1 (ratio) was purified and rotary evaporated at 50°C for 3 hours to obtain the stabilizer; the reaction equation is shown below:

[0032]

[0033] Example 2: Preparation of stabilizer:

[0034] S1: Under nitrogen protection, 5.3 g of 2-(4-aminophenylazo)benzoic acid and 3.4 g of triethylamine were added to 100 ml of anhydrous DMF and stirred until homogeneous. At 0 °C, 30 ml of anhydrous DMF solution containing 6.2 g of fluorenyl chloroformate was slowly added dropwise (over 20 min). The mixture was stirred at 25 °C for 12 h. Then, 10 g of polytetrahydrofuran glycol (number average molecular weight 1000), 2.6 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 0.02 g of 4-dimethylaminopyridine were added. The mixture was stirred for 15 min and reacted at 25 °C for 15 h. The reaction solution was then poured into 300 ml of an ice-water mixture (containing 15 ml of 1M... In HCl, stir for 30 min to neutralize triethylamine; extract three times with ethyl acetate (150 ml each time), combine the organic phases and wash with 150 ml saturated brine, add 10 g anhydrous sodium sulfate and dry for 2 h, filter, concentrate under reduced pressure at 50 °C for 1 h to obtain a concentrate, add the concentrate to 50 ml of a mixed solution of DMF and piperidine (DMF to piperidine volume ratio of 4:1), stir at 25 °C for 35 min to deprotect, then add 400 ml of 0.5 M HCl solution at 0 °C, stir to precipitate, filter, wash successively with 100 ml cold water, 75 ml 5 wt% sodium bicarbonate solution, and 100 ml cold water, dry under vacuum at 40 °C for 12 h to obtain intermediate 1.

[0035] S2: Under nitrogen protection, 1.55 g of 3-mercaptopropionic acid was mixed with 50 ml of anhydrous DMF. 3.8 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 2.3 g of N-hydroxysuccinimide were weighed, mixed, and added in two equal portions (5 min apart) to the 3-mercaptopropionic acid solution. The mixture was stirred and activated in an ice bath for 45 min. At room temperature, 10 g of intermediate 1 and 2 g of triethylamine were added to 50 ml of anhydrous DMF and stirred until homogeneous. The activated 3-mercaptopropionic acid solution was slowly added (dropwise over 20 min). The reaction was carried out at 30 °C for 11 h. The mixture was poured into 200 ml of ice water, filtered, and the filter cake was washed with deionized water (3 × 100 ml). The mixture was then subjected to silica gel column chromatography (eluent: dichloromethane / methanol). V / V Purify the mixture (10:1), then rotary evaporate at 65°C for 2 hours to obtain intermediate 2.

[0036] S3: Under nitrogen protection, 10 g of intermediate 2 and 0.2 g of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite were added to 150 ml of anhydrous DMF and stirred until homogeneous. Then, 26 g of polyethylene glycol monomethyl ether (number average molecular weight 2000) and 0.5 g of p-toluenesulfonic acid were added. The mixture was reacted at 130 °C for 12 h, cooled to room temperature, and 50 ml of saturated sodium bicarbonate solution was added and stirred for 30 min. After separation, the organic phase was retained and washed successively with 100 ml of deionized water and 100 ml of saturated brine. The mixture was dried over 10 g of anhydrous sodium sulfate for 2 h, filtered, and rotary evaporated at 60 °C for 3 h. The solution was dissolved in 100 ml of dichloromethane and subjected to silica gel column chromatography (eluent: petroleum ether / ethyl acetate). V / V Purify the mixture (5:1 ratio), then rotary evaporate at 50°C for 3 hours to obtain the stabilizer.

[0037] Example 3: Preparation of stabilizer:

[0038] S1: Under nitrogen protection, 5.5 g of 2-(4-aminophenylazo)benzoic acid and 3.4 g of triethylamine were added to 100 ml of anhydrous DMF and stirred until homogeneous. At 0 °C, 30 ml of anhydrous DMF solution containing 6.2 g of fluorenyl chloroformate was slowly added dropwise (over 20 min). The mixture was stirred at 25 °C for 12 h. Then, 10 g of polytetrahydrofuran glycol (number average molecular weight 1000), 2.6 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.02 g of 4-dimethylaminopyridine were added. The mixture was stirred for 15 min and reacted at 30 °C for 14 h. The reaction solution was then poured into 300 ml of an ice-water mixture (containing 15 ml of 1M... In HCl, stir for 30 min to neutralize triethylamine; extract three times with ethyl acetate (150 ml each time), combine the organic phases and wash with 150 ml saturated brine, add 10 g anhydrous sodium sulfate and dry for 2 h, filter, concentrate under reduced pressure at 50 °C for 1 h to obtain a concentrate, add the concentrate to 50 ml of a mixed solution of DMF and piperidine (DMF to piperidine volume ratio of 4:1), stir at 25 °C for 35 min to deprotect, then add 400 ml of 0.5 M HCl solution at 0 °C, stir to precipitate, filter, wash successively with 100 ml cold water, 75 ml 5 wt% sodium bicarbonate solution, and 100 ml cold water, dry under vacuum at 40 °C for 12 h to obtain intermediate 1.

[0039] S2: Under nitrogen protection, 1.6 g of 3-mercaptopropionic acid was mixed with 50 ml of anhydrous DMF. 3.8 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 2.3 g of N-hydroxysuccinimide were weighed, mixed, and added in two equal portions (5 min apart) to the 3-mercaptopropionic acid solution. The mixture was stirred and activated in an ice bath for 45 min. At room temperature, 10 g of intermediate 1 and 2 g of triethylamine were added to 50 ml of anhydrous DMF and stirred until homogeneous. The activated 3-mercaptopropionic acid solution was slowly added (dropwise over 20 min). The reaction was carried out at 35 °C for 10 h. The mixture was poured into 200 ml of ice water, filtered, and the filter cake was washed with deionized water (3 × 100 ml). The mixture was then subjected to silica gel column chromatography (eluent: dichloromethane / methanol). V / V Purify the mixture (10:1), then rotary evaporate at 65°C for 5 hours to obtain intermediate 2.

[0040] S3: Under nitrogen protection, 10 g of intermediate 2 and 0.2 g of bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite were added to 150 ml of anhydrous DMF and stirred until homogeneous. Then, 27 g of polyethylene glycol monomethyl ether (number average molecular weight 2000) and 0.5 g of p-toluenesulfonic acid were added. The mixture was reacted at 140 °C for 11 h, cooled to room temperature, and 50 ml of saturated sodium bicarbonate solution was added and stirred for 30 min. After separation, the organic phase was retained and washed successively with 100 ml of deionized water and 100 ml of saturated brine. The mixture was dried over 10 g of anhydrous sodium sulfate for 2 h, filtered, and rotary evaporated at 60 °C for 3 h. The solution was dissolved in 100 ml of dichloromethane and subjected to silica gel column chromatography (eluent: petroleum ether / ethyl acetate). V / V Purify the mixture (5:1 ratio), then rotary evaporate at 50°C for 3 hours to obtain the stabilizer.

[0041] Example 4: Preparation of a highly stable non-silicone defoamer:

[0042] (1) Weigh the following by weight: 15g of hydrogenated castor oil (PEG-40 hydrogenated castor oil), 8g of perfluoropolyether carboxylic acid, 5g of fatty alcohol (lauryl alcohol), 10g of fatty acid ester (glyceryl monooleate), 3g of stabilizer (prepared in Example 1), 4g of emulsifier (epoxytriacetate), and 60g of water.

[0043] (2) Hydrogenated castor oil was stirred in an oil bath at 85°C until it was clear. Fatty alcohol and fatty acid ester were added and stirred at 300 rpm for 30 min. Perfluoropolyether carboxylic acid was added and the temperature was raised to 90°C. The oil phase was obtained by high-speed shearing at 2000 rpm for 1 h. The emulsifier was added to water and ultrasonicated at 50 kHz for 20 min to obtain the aqueous phase. The aqueous phase was preheated to 85°C and the oil phase was slowly added dropwise to the aqueous phase under high-speed stirring at 1500 rpm for 1 h. After the addition was completed, stirring was continued for 30 min. The emulsion was homogenized three times (pressure 25 MPa) using an AH-BASIC 30 high-pressure homogenizer. The homogenized emulsion was cooled to 45°C and the stabilizer was added. The emulsion was stirred at 500 rpm for 1 h and vacuum defoamed (-0.09 MPa, 45°C) for 30 min. After cooling, a high-stability non-silicone defoamer was obtained.

[0044] Example 5: Preparation of a highly stable non-silicone defoamer:

[0045] (1) Weigh the following by weight: 20g of hydrogenated castor oil (PEG-60 hydrogenated castor oil), 12g of perfluoropolyether carboxylic acid, 8g of fatty alcohol (cetyl alcohol), 14g of fatty acid ester (sorbitan monostearate), 5g of stabilizer (prepared in Example 2), 7g of emulsifier (epoxytriacetate), and 65g of water.

[0046] (2) Hydrogenated castor oil was stirred in an oil bath at 85°C until it was clear. Fatty alcohol and fatty acid ester were added and stirred at 300 rpm for 30 min. Perfluoropolyether carboxylic acid was added and the temperature was raised to 90°C. The oil phase was obtained by high-speed shearing at 2000 rpm for 1 h. The emulsifier was added to water and ultrasonicated at 50 kHz for 20 min to obtain the aqueous phase. The aqueous phase was preheated to 85°C and the oil phase was slowly added dropwise to the aqueous phase under high-speed stirring at 1500 rpm for 1 h. After the addition was completed, stirring was continued for 30 min. The emulsion was homogenized three times (pressure 25 MPa) using an AH-BASIC 30 high-pressure homogenizer. The homogenized emulsion was cooled to 45°C and the stabilizer was added. The emulsion was stirred at 500 rpm for 1 h and vacuum defoamed (-0.09 MPa, 45°C) for 30 min. After cooling, a high-stability non-silicone defoamer was obtained.

[0047] Example 6: Preparation of a highly stable non-silicone defoamer:

[0048] (1) Weigh the following by weight: 25g of hydrogenated castor oil (PEG-40 hydrogenated castor oil), 15g of perfluoropolyether carboxylic acid, 10g of fatty alcohol (stearyl alcohol), 18g of fatty acid ester (glyceryl monooleate), 8g of stabilizer (prepared in Example 3), 10g of emulsifier (epoxytriacetate), and 70g of water.

[0049] (2) Hydrogenated castor oil was stirred in an oil bath at 85°C until it was clear. Fatty alcohol and fatty acid ester were added and stirred at 300 rpm for 30 min. Perfluoropolyether carboxylic acid was added and the temperature was raised to 90°C. The oil phase was obtained by high-speed shearing at 2000 rpm for 1 h. The emulsifier was added to water and ultrasonicated at 50 kHz for 20 min to obtain the aqueous phase. The aqueous phase was preheated to 85°C and the oil phase was slowly added dropwise to the aqueous phase under high-speed stirring at 1500 rpm for 1 h. After the addition was completed, stirring was continued for 30 min. The emulsion was homogenized three times (pressure 25 MPa) using an AH-BASIC 30 high-pressure homogenizer. The homogenized emulsion was cooled to 45°C and the stabilizer was added. The emulsion was stirred at 500 rpm for 1 h and vacuum defoamed (-0.09 MPa, 45°C) for 30 min. After cooling, a high-stability non-silicone defoamer was obtained.

[0050] Comparative Example 1

[0051] The raw material composition and preparation method of the highly stable non-silicone defoamer are basically the same as those in Example 5, except that no stabilizer is added to the components.

[0052] Comparative Example 2

[0053] The raw material composition and preparation method of the highly stable non-silicone defoamer are basically the same as those in Example 5, except that the stabilizer is replaced with an equal weight of stabilizer prepared by the following method:

[0054] The preparation method of the stabilizer is basically the same as that in Example 2, except that 2-(4-aminophenylazo)benzoic acid in step S1 is replaced with an equal weight of 4'-amino-2-biphenylcarboxylic acid.

[0055] Comparative Example 3

[0056] The raw material composition and preparation method of the highly stable non-silicone defoamer are basically the same as those in Example 5, except that the stabilizer is replaced with an equal weight of stabilizer prepared by the following method:

[0057] The preparation method of the stabilizer is basically the same as that in Example 2, except that the polytetrahydrofuran diol (number average molecular weight of 1000 Da) in step S1 is replaced with 2.5 g of polytetrahydrofuran diol with a number average molecular weight of 250 Da.

[0058] Comparative Example 4

[0059] The raw material composition and preparation method of the highly stable non-silicone defoamer are basically the same as those in Example 5, except that the stabilizer is replaced with an equal weight of stabilizer prepared by the following method:

[0060] The preparation method of the stabilizer is basically the same as that in Example 2, except that the polytetrahydrofuran diol (number average molecular weight of 1000 Da) in step S1 is replaced with an equal weight of polyethylene glycol (PEG1000).

[0061] Comparative Example 5

[0062] The raw material composition and preparation method of the highly stable non-silicone defoamer are basically the same as those in Example 5, except that the stabilizer is replaced with an equal weight of stabilizer prepared by the following method:

[0063] The preparation method of the stabilizer is basically the same as that in Example 2, except that the polyethylene glycol monomethyl ether (number average molecular weight of 2000 Da) in step S3 is replaced with 9.8 g of polyethylene glycol monomethyl ether with a number average molecular weight of 750 Da.

[0064] The PEG-40 hydrogenated castor oil used in the embodiments and comparative examples of this application is model RH-40, produced by BASF GmbH, Germany; the PEG-60 hydrogenated castor oil is model RH-60, produced by BASF GmbH, Germany; the perfluoropolyether carboxylic acid is grade PFPE-CA-1000, produced by Suzhou Cangmu New Materials Co., Ltd. The CAS number of 2-(4-aminophenylazo)benzoic acid is 85328-89-8.

[0065] The high-stability non-silicone defoamers prepared in Examples 4-6 and Comparative Examples 1-5 were tested for storage stability, high-temperature aging stability, defoaming time, and foam suppression time. The test results are shown in Table 1.

[0066] Storage stability test: The defoamers prepared in Examples 4-6 and Comparative Examples 1-5 were placed at room temperature and stored for 1 month to observe whether they showed stratification.

[0067] High-temperature aging stability test: The defoamers prepared in Examples 4-6 and Comparative Examples 1-5 were placed in an 80℃ electric heating drying oven for 120 hours and then observed to see if stratification occurred.

[0068] Defoaming time test: First, prepare 100 ml of a 1% sodium dodecylbenzenesulfonate aqueous solution, then pour it into a 500 ml graduated cylinder and purge with nitrogen gas to the 500 mark. At this point, add 1 ml of defoamer and record the time required for the bubbles to completely disappear. Repeat the test three times for each sample, and take the average value as the final defoaming time.

[0069] Defoaming time test: First, prepare 100 ml of a 1% sodium dodecylbenzenesulfonate aqueous solution, then pour it into a 500 ml graduated cylinder and add 1 ml of defoamer. Next, purge with nitrogen gas at a flow rate of 2 L / min and record the time it takes for the bubbles to reach the 500 mark. Repeat the test three times for each sample, and take the average value as the final defoaming time.

[0070] Table 1

[0071]

[0072] As can be seen from Table 1, the highly stable non-silicone defoamers prepared in Examples 4-6 of this application have excellent storage stability, high temperature stability, rapid defoaming ability, and foam suppression ability.

[0073] The non-silicone defoamers prepared in Examples 4-6 exhibit excellent stability, rapid defoaming ability, and foam suppression ability because the stabilizers prepared in Examples 4-6 possess hydrophilic and hydrophobic long-chain structures. The hydrophilic segments of polyethylene glycol monomethyl ether extend in the aqueous phase to form a hydration layer, preventing Brownian motion and collisions of defoamer molecules through volume repulsion. The hydrophobic segments of polytetrahydrofuran glycol form molecular anchors through van der Waals forces, preventing the stabilizer from detaching from the interface, thereby significantly improving the storage stability of the non-silicone defoamers. The stabilizers prepared in the examples possess azobenzene dynamic structures; the cis-trans isomerism balance of azobenzene can dynamically regulate interfacial tension and inhibit Ostwald curing of the defoamer. Furthermore, the hydrophobic long-chain segments of polytetrahydrofuran glycol and the hydrophilic long-chain segments of polyethylene glycol monomethyl ether also possess high thermal stability, synergistically improving the high-temperature stability of the non-silicone defoamers. When the defoamer comes into contact with the foam system, environmental stimuli trigger the reversible bond breakage of the stabilizer, rapidly releasing the defoaming active component. After foam breakage, the remaining molecular chains of the stabilizer that are not completely hydrolyzed form a dynamic protective film on the surface of the foam liquid film, which can reduce the surface elasticity of the liquid film and prevent the formation of new foam. In addition, the high water solubility of the hydrophilic segments of polyethylene glycol monomethyl ether enables the defoamer to diffuse rapidly in the aqueous phase, shortening the time to reach the foam interface. At the same time, its steric hindrance effect prevents the aggregation of active components, thereby increasing the foam breakage rate. The hydrophobic effect of polytetrahydrofuran glycol increases the adsorption energy of the active component at the foam interface, inhibiting the loss of active components with the drainage of the foam liquid film, thereby enhancing the foam suppression persistence. Therefore, the defoaming and foam suppression capabilities are improved through the synergistic effect of the hydrophobic segments of polytetrahydrofuran glycol, the dynamic structure of azobenzene, and the hydrophilic segments of polyethylene glycol monomethyl ether. In contrast, Comparative Example 1 did not contain any stabilizer, the stabilizer prepared in Comparative Example 2 lacked the dynamic structure of azobenzene, the stabilizer prepared in Comparative Example 3 had a shorter hydrophobic segment of polytetrahydrofuran diol, the stabilizer prepared in Comparative Example 4 lacked the hydrophobic segment of polytetrahydrofuran diol, and the stabilizer prepared in Comparative Example 5 had a shorter hydrophilic segment of polyethylene glycol monomethyl ether. Therefore, the stabilizers prepared in the comparative examples were less effective than those in the examples, resulting in relatively poor performance of the prepared non-silicone defoamers.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A highly stable non-silicone defoamer, characterized in that, The raw materials include the following parts by weight: 15-25 parts hydrogenated castor oil, 8-15 parts perfluoropolyether carboxylic acid, 5-10 parts fatty alcohol, 10-18 parts fatty acid ester, 3-8 parts stabilizer, 4-10 parts emulsifier, and 60-70 parts deionized water. The stabilizer is prepared by the following method: S1: Under nitrogen protection, 2-(4-aminophenylazo)benzoic acid, triethylamine and anhydrous DMF are mixed and then slowly added to an anhydrous DMF solution of 9-fluorenyl chloroformate. The mixture is stirred, and then polytetrahydrofurandiol, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine are added to give intermediate 1. S2: Under nitrogen protection, 3-mercaptopropionic acid is mixed with anhydrous DMF, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide are added for activation; then intermediate 1 and triethylamine are slowly added to the DMF solution to react and obtain intermediate 2. S3: Under nitrogen protection, intermediate 2, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite and anhydrous DMF are mixed, and polyethylene glycol monomethyl ether and p-toluenesulfonic acid are added to react and obtain the stabilizer.

2. The highly stable non-silicone defoamer according to claim 1, characterized in that, In step S1, the mass ratio of polytetrahydrofuran diol to 2-(4-aminophenylazo)benzoic acid is 1:(0.5-0.55).

3. The highly stable non-silicone defoamer according to claim 1, characterized in that, In step S2, the mass ratio of intermediate 1 to 3-mercaptopropionic acid is 1:(0.15-0.16).

4. The highly stable non-silicone defoamer according to claim 1, characterized in that, In step S3, the mass ratio of intermediate 2 to polyethylene glycol monomethyl ether is 1:(2.5-2.7).

5. The highly stable non-silicone defoamer according to claim 1, characterized in that, The reaction temperature in step S1 is 25-30℃, and the reaction time is 14-16h.

6. The highly stable non-silicone defoamer according to claim 1, characterized in that, The reaction temperature in step S2 is 25-35℃, and the reaction time is 10-12h.

7. The highly stable non-silicone defoamer according to claim 1, characterized in that, The reaction temperature in step S3 is 120-140℃, and the reaction time is 11-13h.

8. The highly stable non-silicone defoamer according to claim 1, characterized in that, The hydrogenated castor oil is one of PEG-40 hydrogenated castor oil and PEG-60 hydrogenated castor oil.

9. The highly stable non-silicone defoamer according to claim 1, characterized in that, The fatty alcohol is one of lauryl alcohol, cetyl alcohol, and stearyl alcohol.

10. A highly stable non-silicone defoamer according to claim 1, characterized in that, The fatty acid ester is one of glyceryl monooleate and sorbitan monostearate.

11. The highly stable non-silicone defoamer according to claim 1, characterized in that, The emulsifier is epoxytriacetic acid ester.

12. A method for preparing a highly stable non-silicone defoamer according to any one of claims 1-11, characterized in that, Includes the following steps: (1) Weigh out by weight; Hydrogenated castor oil 15-25 parts, perfluoropolyether carboxylic acid 8-15 parts, fatty alcohol 5-10 parts, fatty acid ester 10-18 parts, stabilizer 3-8 parts, emulsifier 4-10 parts, deionized water 60-70 parts. (2) Heat hydrogenated castor oil, add fatty alcohol and fatty acid ester, stir and mix well, add perfluoropolyether carboxylic acid, and shear at high speed to obtain oil phase; add emulsifier to water and sonicate to obtain aqueous phase; preheat aqueous phase, slowly drip oil phase into aqueous phase under high speed stirring, continue stirring after dripping, homogenize under high pressure 3 times, cool the homogenized emulsion, add stabilizer, stir and mix well, and defoam under vacuum to obtain high-stability non-silicone defoamer.

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