Star-shaped polyether organic silicon copolymer as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of polyether organic silicon copolymer preparation, and relates to a star-shaped polyether organic silicon copolymer as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out ring opening polymerization on dimethyl cyclosiloxane and octamethylcyclotetrasiloxane, crosslinking with 1, 5-hexadiene to prepare a hydrogen-containing polymethylsiloxane skeleton, carrying out ring opening polymerization on 2, 4, 7, 9-tetramethyl-5-decyne-4, 7-diol serving as a raw material and epoxypropane to obtain an alkyne glycol ether intermediate, carrying out ring opening polymerization on the alkyne glycol ether intermediate and the 1, 5-hexadiene to obtain a hydrogen-containing polymethylsiloxane skeleton, and carrying out hydrogen-containing polymethylsiloxane skeleton. And carrying out hydrosilylation on the polyether and hydrogen polymethylsiloxane to obtain the star-shaped polyether organic silicon copolymer which can be used as an active component of a defoaming agent. Compared with straight-chain polyether, the star-shaped branch structure enables Van der Waals force, hydrogen bonds and other acting forces to be diversified, the stability of a foam liquid film can be destroyed more quickly, and quick defoaming is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of polyether organosilicon copolymer preparation, in particular to a star-shaped polyether organosilicon copolymer and a preparation method and application thereof. Background Art

[0002] Linear polyether silicone copolymers are a class of high-performance materials created by combining polyether segments with a siloxane backbone. These combinations can create new materials that combine the advantages of both, such as self-emulsifying defoamers and high-efficiency foam levelers. These materials are widely used in the chemical industry, but their performance is limited by the linear molecular chain's mobility. The introduction of branched structures, such as star-shaped and comb-shaped ones, can enhance their functionality. Due to their unique topology, star-shaped structures exhibit significant advantages in reducing solution viscosity, increasing surface activity, and regulating phase behavior.

[0003] Chinese patent application publication number CN104448323A discloses a star-shaped, comb-like polyether organosilicon copolymer and its preparation method. In this copolymer, a diene and heptamethyltrisiloxane are connected via silicon-carbon bonds to form branching points. Polysiloxane side chains are introduced, connected to the branching points via Si-H-Si chains. The side chains are polyether chains, connected to the polysiloxane chains via silicon-carbon bonds. The Si-H bonds in this structure are susceptible to hydrolysis, dehydrogenation, condensation, or hydrosilylation side reactions at high temperatures or in the presence of Lewis acid or base catalysts. Alternatively, they can generate silanol groups in an oxidizing environment, causing segmental degradation or crosslinking, disrupting the copolymer's molecular structure and affecting its surface activity, defoaming properties, and mechanical properties. Summary of the Invention

[0004] The present invention provides a star-shaped polyether organosilicon copolymer, its preparation method, and application. This star-shaped polyether organosilicon copolymer is an active ingredient in water-based coating defoamers. The organosilicon backbone is grafted with polyether multi-arm segments, which dynamically stretch and simultaneously adsorb on multiple bubble surfaces, rapidly disrupting the elasticity of the liquid film and increasing defoaming speed. The star-shaped branched structure reduces chain entanglement and lowers system viscosity, making it easier to penetrate the foam interface, forming a durable barrier at the interface and inhibiting foam regeneration.

[0005] To achieve the above-mentioned purpose, the present invention provides a star-shaped polyether organosilicon copolymer, the structure of which is shown below:

[0006]

[0007] Wherein, the value of m is an integer between 5 and 10; α is 1, and the value of β is an integer between 2 and 5.

[0008] The present invention also provides a method for preparing a star-shaped polyether organosilicon copolymer, comprising:

[0009] Step S1, dispersing 2,4,7,9-tetramethyl-5-decyne-4,7-diol in a first solvent, adding propylene oxide and a first catalyst, adding acetic acid after the reaction is completed, filtering, and obtaining an acetylene glycol ether intermediate;

[0010] Step S2, dispersing dimethylcyclosiloxane and octamethylcyclotetrasiloxane in a second solvent, adding a second catalyst, carrying out a first reaction, adding 1,5-hexadiene, a third catalyst, and triethylamine, carrying out a second reaction, to obtain hydrogen-containing polymethylsiloxane;

[0011] Step S3: adding the acetylene glycol ether intermediate to hydrogen-containing polymethylsiloxane, adding a third catalyst, and reacting to obtain a star-shaped polyether organosilicon copolymer.

[0012] Preferably, in step S1, the first solvent is any one or more of tetrahydrofuran, toluene, and dioxane.

[0013] Preferably, in step S1, the first catalyst is any one or more of sodium hydroxide and potassium hydroxide.

[0014] Preferably, in step S1, the reaction temperature is 80-100° C., and the reaction time is 4-6 hours.

[0015] Preferably, in step S1, the mass ratio of the 2,4,7,9-tetramethyl-5-decyne-4,7-diol, the first solvent, propylene oxide, and the first catalyst is 1:(3-5):(2.5-5.5):(0.01-0.03).

[0016] Preferably, in step S2, the second solvent is any one or more of toluene and xylene.

[0017] Preferably, the second catalyst is concentrated sulfuric acid.

[0018] Preferably, in step S2, the temperature of the first reaction is 40-60° C., and the time of the first reaction is 6-8 hours.

[0019] Preferably, in step S2, the third catalyst is chloroplatinic acid.

[0020] Preferably, in step S2, the temperature of the second reaction is 60-80° C., and the time of the second reaction is 2-3 hours.

[0021] Preferably, in step S2, the mass ratio of the dimethylcyclosiloxane, octamethylcyclotetrasiloxane, the second solvent, the second catalyst, 1,5-hexadiene, the third catalyst and triethylamine is 1: (12.3-24.6): (30-50): (0.05-0.1): (5-12): (0.025-0.05): (0.1-0.15).

[0022] Preferably, in step S3, the reaction temperature is 60-80° C., and the reaction time is 4-6 hours.

[0023] Preferably, in step S3, the mass ratio of the hydrogen-containing polymethylsiloxane, the acetylene glycol ether intermediate and the third catalyst is 1: (1.25-2.55): (0.00025-0.00035).

[0024] The present invention also provides an application of a star-shaped polyether organosilicon copolymer in the preparation of a defoaming agent.

[0025] Compared with the prior art, the beneficial effects of the present invention are embodied in:

[0026] (1) The present invention adopts octamethylcyclotetrasiloxane and dimethylcyclosiloxane ring-opening polymerization, and uses 1,5-hexadienyl as a cross-linking agent to prepare a hydrogen-containing polymethylsiloxane skeleton cross-linked with siloxane and carbon chain. The low surface energy of siloxane is combined with the hydrophobicity of the carbon chain, so that the product has stronger defoaming ability and durability in the aqueous system. The presence of the carbon chain can reduce the intermolecular force and improve the fluidity of the lubricant; the acetylene glycol ether and siloxane are reacted by hydrosilylation to introduce polyether chain segments to obtain a star-shaped polyether silicone copolymer.

[0027] (2) The active ingredient of the star-shaped polyether organosilicon copolymer water-based paint defoamer prepared by the present invention has multiple branches in the star-shaped structure compared with the linear polyether, and the van der Waals force, hydrogen bond and other forces between molecules are diversified. When it comes into contact with foam, it can destroy the stability of the foam liquid film more quickly and achieve rapid defoaming. The multiple branches in the structure increase the flexibility and fluidity of the polymer molecules, which is conducive to its diffusion in the foam system. That is, when the defoamer molecules diffuse into the foam liquid film, they will change the local composition and properties of the liquid film, reduce the surface viscosity and elasticity of the liquid film, and thus make the foam easier to break. The structure of the linear polyether defoamer is poor in diffusion performance, and it takes longer to reach an effective concentration in the foam liquid film to achieve defoaming. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a synthetic route for acetylene glycol ether intermediates.

[0029] Figure 2 This is a synthetic route for star-shaped polyether silicone copolymers.

[0030] Figure 3 This is a real picture of the star-shaped polyether silicone copolymer defoamer. DETAILED DESCRIPTION

[0031] The following examples are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0032] Unless otherwise specified, the reagents and equipment involved in the following examples were purchased from commercial channels.

[0033] Example 1

[0034] A star-shaped polyether organosilicon copolymer, the preparation method of which comprises:

[0035] Step S1: Disperse 10 g of 2,4,7,9-tetramethyl-5-decyne-4,7-diol in 30 g of dioxane, add 25 g of propylene oxide and 0.1 g of sodium hydroxide, react at 80 ° C for 6 h, add acetic acid to neutralize the excess sodium hydroxide, filter, and obtain an acetylene glycol ether intermediate, such as Figure 1 shown.

[0036] Step S2: Disperse 1 g of dimethylcyclosiloxane and 12.3 g of octamethylcyclotetrasiloxane in 30 g of toluene, add 0.05 g of concentrated sulfuric acid, react at 40° C. for 8 h, add 5 g of 1,5-hexadiene, 0.025 g of chloroplatinic acid, and 0.1 g of triethylamine, and react at 60° C. for 3 h to obtain hydrogenated polymethylsiloxane.

[0037] Step S3: add 10g of the acetylene glycol ether intermediate to 12.5g of hydrogen-containing polymethylsiloxane, add 0.0025g of chloroplatinic acid, and react to obtain a star-shaped polyether organosilicon copolymer, such as Figure 2 shown.

[0038] Example 2

[0039] A star-shaped polyether organosilicon copolymer, the preparation method of which comprises:

[0040] Step S1: Disperse 10 g of 2,4,7,9-tetramethyl-5-decyne-4,7-diol in 40 g of tetrahydrofuran, add 40 g of propylene oxide and 0.2 g of potassium hydroxide, react at 90 ° C for 5 h, add acetic acid to neutralize the excess potassium hydroxide, filter, and obtain an acetylene glycol ether intermediate, such as Figure 1 shown.

[0041] Step S2: Disperse 1 g of dimethylcyclosiloxane and 18.5 g of octamethylcyclotetrasiloxane in 40 g of xylene, add 0.1 g of concentrated sulfuric acid, react at 50° C. for 7 h, add 8 g of 1,5-hexadiene, 0.04 g of chloroplatinic acid, and 0.15 g of triethylamine, and react at 70° C. for 2.5 h to obtain hydrogenated polymethylsiloxane.

[0042] Step S3: add 10g of the acetylene glycol ether intermediate to 17.5g of hydrogenated polymethylsiloxane, add 0.003g of chloroplatinic acid, and react to obtain a star-shaped polyether organosilicon copolymer, such as Figure 2 shown.

[0043] Example 3

[0044] A star-shaped polyether organosilicon copolymer, the preparation method of which comprises:

[0045] Step S1: Disperse 10 g of 2,4,7,9-tetramethyl-5-decyne-4,7-diol in 50 g of toluene, add 55 g of propylene oxide and 0.3 g of sodium hydroxide, react at 100 ° C for 4 h, add acetic acid to neutralize the excess sodium hydroxide, filter, and obtain an acetylene glycol ether intermediate, such as Figure 1 shown.

[0046] Step S2: Disperse 1 g of dimethylcyclosiloxane and 24.6 g of octamethylcyclotetrasiloxane in 50 g of toluene, add 0.1 g of concentrated sulfuric acid, react at 60° C. for 6 h, add 12 g of 1,5-hexadiene, 0.05 g of chloroplatinic acid, and 0.15 g of triethylamine, and react at 80° C. for 2 h to obtain hydrogenated polymethylsiloxane.

[0047] Step S3: add 10g of the acetylene glycol ether intermediate to 25.5g of hydrogenated polymethylsiloxane, add 0.0035g of chloroplatinic acid, and react to obtain a star-shaped polyether organosilicon copolymer, such as Figure 2 shown.

[0048] Example 4

[0049] A defoaming agent, the preparation method of which comprises:

[0050] The star-shaped polyether organosilicon copolymer prepared in Example 1 was dispersed in propylene glycol, Span-80 and deionized water were added, and homogenized to obtain an aqueous defoamer emulsion, polyvinyl alcohol, sodium benzoate, and attapulgite were added, and stirred to obtain a star-shaped polyether organosilicon copolymer defoamer. Figure 3 shown.

[0051] Example 5

[0052] A defoaming agent, the preparation method of which comprises:

[0053] The star-shaped polyether organosilicon copolymer prepared in Example 2 was dispersed in propylene glycol, Span-80 and deionized water were added, and homogenized to obtain an aqueous defoamer emulsion, polyvinyl alcohol, sodium benzoate, and attapulgite were added, and stirred to obtain a star-shaped polyether organosilicon copolymer defoamer. Figure 3 shown.

[0054] Example 6

[0055] A defoaming agent, the preparation method of which comprises:

[0056] The star-shaped polyether organosilicon copolymer prepared in Example 3 was dispersed in propylene glycol, Span-80 and deionized water were added, and homogenized to obtain an aqueous defoamer emulsion, polyvinyl alcohol, sodium benzoate, and attapulgite were added, and stirred to obtain a star-shaped polyether organosilicon copolymer defoamer. Figure 3 shown.

[0057] Comparative Example 1

[0058] A commercially available silicone defoamer, model TEGO-902W (BASF).

[0059] Comparative Example 2

[0060] A commercially available organosilicon defoamer, model BYK-022 (BYK, Germany).

[0061] Performance testing:

[0062] (1) Defoaming efficiency test: Use a measuring cylinder to measure 50 mL of foaming liquid into a 100 mL measuring cylinder with a stopper. Use a pipette to draw 1 mL of defoaming agent into the measuring cylinder with a stopper. Shake vigorously 30 times at room temperature, let it stand, and start a stopwatch at the same time to record the time required for the foam volume to be less than 5 mL.

[0063] (2) Thermal stability test:

[0064] Static thermal stability test: The defoamers prepared in Examples 4 to 6 were placed in a high-temperature aging box and allowed to stand at 150°C for 24 hours. Their appearance was observed and their defoaming efficiency was tested using the method in (1).

[0065] Dynamic high-temperature defoaming test: Add the foaming liquid into the autoclave and continue blowing at 150°C and 5 MPa. Record the time required for the foam height to be less than 5 mL.

[0066] (3) Coating defect evaluation: The defoaming agents of Examples 4 to 6 and Comparative Examples 1 and 2 were mixed with water-based acrylic paint, water-based polyurethane paint, and water-based epoxy resin paint, respectively, and applied on a glass substrate. The mixture was dried at 50 to 60° C. for 1 to 2 h, and the coating surface was observed for peeling, pinholes, cracks, and shrinkage cavities.

[0067] Table 1 Defoaming efficiency test data

[0068]

[0069] As shown in Table 1, the defoamers prepared in Examples 4 to 6 all reduced the foam height from 50 mL to less than 5 mL within 15 seconds, while the defoamer in Comparative Example 1 reduced the foam from 50 mL to less than 5 mL in 31 seconds, and the defoamer in Comparative Example 2 reduced the foam from 50 mL to less than 5 mL in 28 seconds. The experiments demonstrated that the defoamers prepared in Examples 4 to 6 had good defoaming performance.

[0070] Table 2 Thermal stability test data

[0071]

[0072]

[0073] As shown in Table 2, after adding the defoaming agents of Examples 4 to 6 and Comparative Examples 1 to 2 and placing at high temperature for 24 hours, the morphology and appearance did not change, and no stratification or thickening occurred. In addition, the foam was reduced from 50 mL to less than 5 mL within 15 seconds. Under the conditions of 150° C. and 5 MPa, continuous aeration was performed to a foam height of 50 mL. The defoaming agents prepared in Examples 4 to 6 reduced the foam from 50 mL to less than 5 mL within 20 seconds, while Comparative Example 1 required 47 seconds and Comparative Example 2 required 49 seconds.

[0074] Table 3 Coating defect evaluation test results

[0075]

[0076] As shown in Table 3, the three coatings added with Examples 4 to 6 did not show any shedding or cracking, and the coatings had no pinholes or shrinkage holes and were smooth and flat; the coatings added with the defoaming agents of Comparative Examples 1 and 2 did not show any shedding, but pinholes and shrinkage holes existed on the surface of some coatings. Experiments have shown that the defoaming agents of Examples 4 to 6 have good compatibility and dispersibility with the coatings, and when added to the coatings, they can effectively exert a defoaming effect without affecting the curing of the coating, the appearance and performance of the coating.

[0077] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A star-shaped polyether silicone copolymer, characterized in that: The structure of the star-shaped polyether silicone copolymer is shown below: Wherein, m is an integer between 5 and 10, α is 1, and β is an integer between 2 and 5.

2. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 1, wherein: include: Step S1, dispersing 2,4,7,9-tetramethyl-5-decyne-4,7-diol in a first solvent, adding propylene oxide and a first catalyst, adding acetic acid after the reaction is completed, filtering, and obtaining an acetylene glycol ether intermediate; Step S2, dispersing dimethylcyclosiloxane and octamethylcyclotetrasiloxane in a second solvent, adding a second catalyst, carrying out a first reaction, adding 1,5-hexadiene, a third catalyst, and triethylamine, carrying out a second reaction, to obtain hydrogen-containing polymethylsiloxane; Step S3: adding the acetylene glycol ether intermediate to hydrogen-containing polymethylsiloxane, adding a third catalyst, and reacting to obtain a star-shaped polyether organosilicon copolymer.

3. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 2, wherein: In step S1, the first solvent is any one or more of tetrahydrofuran, toluene, and dioxane; the first catalyst is any one or more of sodium hydroxide and potassium hydroxide; the reaction temperature is 80-100° C., and the reaction time is 4-6 hours.

4. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 2, wherein: In the step S1, the mass ratio of the 2,4,7,9-tetramethyl-5-decyne-4,7-diol, the first solvent, propylene oxide, and the first catalyst is 1:(3-5):(2.5-5.5):(0.01-0.03).

5. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 2, wherein: In step S2, the second solvent is any one or more of toluene and xylene; and the second catalyst is concentrated sulfuric acid.

6. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 2, characterized in that: In step S2, the temperature of the first reaction is 40-60° C., and the time of the first reaction is 6-8 hours; the third catalyst is chloroplatinic acid; the temperature of the second reaction is 60-80° C., and the time of the second reaction is 2-3 hours.

7. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 2, characterized in that: In step S2, the mass ratio of the dimethylcyclosiloxane, octamethylcyclotetrasiloxane, the second solvent, the second catalyst, 1,5-hexadiene, the third catalyst and triethylamine is 1: (12.3-24.6): (30-50): (0.05-0.1): (5-12): (0.025-0.05): (0.1-0.15).

8. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 2, characterized in that: In step S3, the reaction temperature is 60-80° C., and the reaction time is 4-6 hours.

9. The method for preparing a star-shaped polyether organosilicon copolymer according to claim 2, characterized in that: In the step S3, the mass ratio of the hydrogen-containing polymethylsiloxane, the acetylene glycol ether intermediate and the third catalyst is 1: (1.25-2.55): (0.00025-0.00035).

10. Use of the star-shaped polyether organosilicon copolymer according to claim 1 in the preparation of a defoaming agent.

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