Preparation method of alkyl modified silicone oil single-phase immersed cooling liquid and application of alkyl modified silicone oil single-phase immersed cooling liquid in cooling of data center

Abstract

The invention discloses a preparation method of alkyl modified silicone oil single-phase immersed coolant and application of the alkyl modified silicone oil single-phase immersed coolant in data center cooling, and belongs to the technical field of coolants.The preparation method comprises the steps that firstly, long-chain alpha olefin is used for modifying tetramethylcyclotetrasiloxane to obtain long-chain alkyl tetramethylcyclotetrasiloxane; then, long-chain alkyl tetramethyl cyclotetrasiloxane and octamethyl cyclotetrasiloxane serve as monomers, modified double-long-chain alkyl tetramethyl disiloxane serves as an end-capping reagent, copolymerization is conducted, and the long-chain alkyl end-capped single-long-chain alkyl monomethyl siloxane / dimethyl siloxane copolymer is obtained. By adopting the method disclosed by the invention, a copolymer product with relatively low steric hindrance can be prepared, a side chain alkyl group and a polymer structure can be accurately regulated and controlled, silicon-hydrogen bonds and olefin are not remained in the obtained product, and the product can be used as a single-phase cooling liquid of an immersed liquid cooling system of a data center to be applied to immersed cooling of the data center and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling liquids, and in particular to a method for preparing an alkyl-modified silicone oil single-phase immersion cooling liquid and application of the same in cooling of a data center. Background Art

[0002] As the foundation of computing power infrastructure, servers and other equipment are facing increasingly prominent energy consumption and heat dissipation issues caused by the growth of computing power. Air cooling and liquid indirect cooling are no longer able to meet the heat dissipation requirements of high heat flux density. As greening and low carbonization become the development trend, it is crucial to switch from air cooling to liquid cooling to create energy-saving green computing power. Immersion liquid cooling allows the heat-generating components to directly contact the liquid coolant, which can greatly eliminate the influence of contact thermal resistance and conduction thermal resistance, significantly improve heat dissipation performance, and has attracted widespread attention.

[0003] Silicone oil is an ideal insulating heat-conducting fluid for direct cooling, but it is difficult to achieve a balance in performance parameters such as flash point and viscosity for conventional dimethyl silicone oil. Dimethyl silicone oil with a higher flash point usually has a higher viscosity and has obvious swelling properties for polymers such as plastics and rubber. At present, a common means of improving the performance of silicone oil is to introduce long-chain alkyl groups into the side chains of oligosiloxane segments. This method can increase the flash point and reduce the viscosity while improving its compatibility with polymers such as plastics and rubbers, reducing its swelling in plastics, rubbers, etc., so that it can be better applied to different usage scenarios.

[0004] However, the preparation of alkyl-modified silicone oil is mainly carried out by hydrosilylation of hydrogenated silicone oil on the market with long-chain α-olefins to introduce long-chain alkyl groups into the side chains to obtain silicone oil containing side chain alkyl. Then, under the catalysis of acid (for example: concentrated sulfuric acid, trifluoromethanesulfonic acid, etc.) or base (tetramethylammonium hydroxide, sodium hydroxide, etc.), hexamethyldisiloxane is used as a capping agent to copolymerize the silicone oil containing side chain alkyl with octamethylcyclotetrasiloxane to prepare modified silicone oil containing a certain amount of alkyl side chains. At the same time, many studies have shown that when hydrogenated silicone oil undergoes hydrosilylation, it is easy to undergo dehydrogenation self-coupling to form gels and elastomers, resulting in increased viscosity and even cross-linking and curing. This phenomenon is mainly due to the increase in the number of Si-H bonds in hydrogenated silicone oil, which is prone to explosion under the action of catalysts and temperature, making the originally linear molecular structure more complex and disordered. Moreover, due to the randomness of the structure of hydrogenated silicone oil in the market, the structure of the synthesized alkyl-modified silicone oil and the proportion of alkyl groups are relatively complex and inaccurate, and the regulation of the side chain alkyl ratio and polymer structure cannot be achieved during the experimental design period. In CN118772409 A, octene and decene are first added to tetramethylcyclotetrasiloxane, and the resulting addition product is used as a monomer, and hexamethyldisiloxane is used as a capping agent to carry out a synthesis reaction to obtain a homopolymer of polyoctyl (or decyl) methylsiloxane. The alkyl-modified silicone oil homopolymer prepared by this method improves the compatibility with silicone rubber, but the compatibility with other rubber materials such as EPDM is poor. In addition, the method introduces high-density long-chain alkyl groups in the side chain, which greatly increases the viscosity of the system and does not meet the data center cooling industry standards.

[0005] In view of this, this application is filed. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing an alkyl-modified silicone oil single-phase immersion coolant and its application in data center cooling. The alkyl-modified silicone oil single-phase immersion coolant can achieve the technical indicators of a single-phase coolant for a data center immersion liquid cooling system, has good compatibility with a variety of rubbers such as silicone rubber and EPDM rubber, has a relatively low viscosity, can be used as a single-phase coolant for a data center immersion liquid cooling system in data center immersion cooling, and has broad application prospects.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for preparing an alkyl-modified silicone oil single-phase immersion coolant comprises the following steps:

[0009] (1) uniformly mixing tetramethylcyclotetrasiloxane and a first solvent, adding a mixed solution of a long-chain alpha olefin, a second solvent, and a catalyst, and reacting to obtain a long-chain alkylcyclotetrasiloxane;

[0010] (2) uniformly mixing tetramethyldisiloxane and a first solvent, adding a mixed solution of a long-chain alpha olefin, a second solvent, and a catalyst, and reacting to obtain a modified di-long-chain alkyltetramethyldisiloxane;

[0011] (3) mixing long-chain alkyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, and modified long-chain alkyl tetramethyldisiloxane uniformly, adding a catalyst, and reacting to obtain an alkyl-modified silicone oil single-phase immersion coolant;

[0012] The long chain alpha olefins include C6-C 14 Ene.

[0013] The invention first modifies tetramethylcyclotetrasiloxane with long-chain alpha olefin to obtain long-chain alkyltetramethylcyclotetrasiloxane, and then copolymerizes long-chain alkyltetramethylcyclotetrasiloxane and octamethylcyclotetrasiloxane as monomers and modified di-long-chain alkyltetramethyldisiloxane as an end-capping agent to obtain a long-chain alkyl-terminated single-long-chain alkyl monomethylsiloxane / dimethylsiloxane copolymer. The method of the invention can prepare a copolymer product with lower steric hindrance, and can accurately control the side chain alkyl and polymer structure. The obtained product will not have residual silicon-hydrogen bonds and olefins, will not have dehydrogenation self-coupling phenomenon, will not form gels and elastomers, and will not have implosion.

[0014] The present invention introduces long-chain alkyl groups and -Si(CH3)2-O- units into the main chain of silicone oil through molecular design, thereby avoiding entanglement of long side chains with adjacent molecules and reducing intermolecular forces to reduce viscosity; not only long-chain alkyl units but also -Si(CH3)2-O- units are introduced into the main chain of silicone oil, which not only ensures good compatibility with silicone rubber, but also has good compatibility with various rubbers such as EPDM rubber, and can be used as a single-phase coolant for data center immersion liquid cooling systems in data center immersion cooling, and has broad application prospects.

[0015] As a preferred embodiment of the present invention, the molar ratio of the tetramethylcyclotetrasiloxane to the long-chain alpha olefin is 1:(4-5).

[0016] As a preferred embodiment of the present invention, the usage ratio of the tetramethylcyclotetrasiloxane and the first solvent is 1 g: (2-10) mL; and / or

[0017] The usage ratio of the long-chain alpha olefin, the second solvent and the catalyst is 1 g: (0.5-10) mL: (0.5-5) μL.

[0018] As a preferred embodiment of the present invention, the reaction temperature in step (1) is 50 to 90° C., and the reaction time is 2 to 8 hours.

[0019] The method for preparing an alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that the molar ratio of the tetramethyldisiloxane to the long-chain alpha olefin is 1:(2-3).

[0020] The method for preparing an alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that the amount ratio of the tetramethyldisiloxane to the first solvent is 1g: (2-10)mL; and / or

[0021] The usage ratio of the long-chain alpha olefin, the second solvent and the catalyst is 1 g: (0.5-10) mL: (0.5-5) μL.

[0022] The method for preparing an alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that the reaction temperature in step (2) is 50 to 90° C. and the reaction time is 2 to 8 hours.

[0023] As a preferred embodiment of the present invention, the molar ratio of the long-chain alkyl cyclotetrasiloxane, octamethylcyclotetrasiloxane and modified long-chain alkyl tetramethyldisiloxane is (1.5-3):(1.5-4.5):1.

[0024] As a preferred embodiment of the present invention, the amount of the catalyst in step (3) is 0.5-5% of the total mass of the long-chain alkyl cyclotetrasiloxane, octamethylcyclotetrasiloxane and modified long-chain alkyl tetramethyldisiloxane.

[0025] As a preferred embodiment of the present invention, the reaction temperature in step (3) is 50 to 120° C. and the reaction time is 10 to 14 hours.

[0026] As a preferred embodiment of the present invention, the first solvent and the second solvent independently include at least one of petroleum ether, n-hexane, ethyl acetate and toluene.

[0027] As a preferred embodiment of the present invention, the catalyst in steps (1) and (2) includes at least one of a Karstedt catalyst and a chloroplatinic acid catalyst.

[0028] As a preferred embodiment of the present invention, the catalyst in step (3) includes at least one of concentrated sulfuric acid, trifluoromethanesulfonic acid, and solid acid.

[0029] The present invention also provides an application of an alkyl-modified silicone oil single-phase immersion cooling liquid in immersion cooling of a data center.

[0030] The beneficial effect of the present invention is that the present invention firstly modifies tetramethylcyclotetrasiloxane with a long-chain alpha olefin to obtain a long-chain alkyltetramethylcyclotetrasiloxane, and then uses the long-chain alkyltetramethylcyclotetrasiloxane and octamethylcyclotetrasiloxane as monomers and the modified di-long-chain alkyltetramethyldisiloxane as a capping agent to carry out copolymerization to obtain a long-chain alkyl-capped mono-long-chain alkyl monomethylsiloxane / dimethylsiloxane copolymer. The method of the present invention can be used to prepare copolymer products with lower steric hindrance, and the side chain alkyl and polymer structure can be accurately regulated. The obtained product will not have residual silicon-hydrogen bonds and olefins, will not undergo self-coupling during dehydrogenation, will not form gels or elastomers, and will not undergo explosion polymerization. Long-chain alkyl groups and -Si(CH3)2-O- units are introduced into the main chain of silicone oil by molecular design to avoid entanglement of long side chains with adjacent molecules, thereby reducing intermolecular forces and reducing viscosity. Not only long-chain alkyl units are introduced into the main chain of silicone oil, but -Si(CH3)2-O- units are also introduced, which not only ensures good compatibility with silicone rubber, but also has good compatibility with various rubbers such as EPDM rubber, and can be used as a single-phase coolant for an immersion liquid cooling system in a data center for immersion cooling in a data center, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the H-NMR spectrum of the long-chain alkyl cyclotetrasiloxane prepared in Example 1.

[0032] Figure 2 This is the H-NMR spectrum of the long-chain alkyl cyclotetrasiloxane prepared in Example 2.

[0033] Figure 3 This is the H-NMR spectrum of the long-chain alkyl cyclotetrasiloxane prepared in Example 3.

[0034] Figure 4 This is the H-NMR spectrum of the long-chain alkyl cyclotetrasiloxane prepared in Example 4.

[0035] Figure 5 This is the H-NMR spectrum of the long-chain alkyl cyclotetrasiloxane prepared in Example 5.

[0036] Figure 6 This is the H-NMR spectrum of 1,3,5,7-tetramethyl-dihexyldisiloxane prepared in Example 6.

[0037] Figure 7 This is the nuclear magnetic hydrogen spectrum of the long-chain alkyl-terminated modified silicone oil single-phase immersion coolant prepared in Example 8.

[0038] Figure 8 This is the H-NMR spectrum of the alkyl-modified silicone oil prepared in Comparative Example 4.

[0039] Fig. 9 This is a compatibility test diagram of the alkyl-modified silicone oil and the silicone material in Example 7 and Comparative Example 5. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0041] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0042] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0043] In the present application, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0044] Unless otherwise specified, the components, raw materials or instruments used in the embodiments and comparative examples of the present invention are all commercially available raw materials or instruments, and the components and raw materials used in each parallel experiment are all of the same kind.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0046] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims.

[0047] Example 1

[0048] A method for preparing 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (long-chain alkylcyclotetrasiloxane), comprising the following steps:

[0049] 24g of tetramethylcyclotetrasiloxane and 50mL of n-hexane were mixed and added to a 250mL three-necked flask, and a mixed solution of 50mL of n-hexane, 40μL of Karstedt catalyst and 33.7g of 1-hexene was added in batches at a stirring speed of 300r / min, and the temperature was raised to 70°C for reaction for 12h. After the reaction was completed, the filtrate was filtered, and the solvent was removed by reduced pressure distillation to obtain 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane with a yield of 93%.

[0050] The H NMR spectrum of the prepared 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane is as follows: Figure 1 As shown: 1 H NMR (400MHz, Chloroform-d) δ1.38-1.22(m,32H),0.90-0.84(m,12H),0.55-0.47(m,8H),0.06-0.05(m,12H).

[0051] Example 2

[0052] A method for preparing 1,3,5,7-tetramethyl-1,3,5,7-tetraoctylcyclotetrasiloxane (long-chain alkylcyclotetrasiloxane), comprising the following steps:

[0053] 24g of tetramethylcyclotetrasiloxane and 50mL of n-hexane were mixed and added to a 250mL three-necked flask, and a mixed solution of 50mL of n-hexane, 40μL of Karstedt catalyst and 44.9g of 1-octene was added in batches at a stirring speed of 300r / min, and the temperature was raised to 70°C for reaction for 12h. After the reaction was completed, the filtrate was filtered, and the solvent was removed by reduced pressure distillation to obtain 1,3,5,7-tetramethyl-1,3,5,7-tetraoctylcyclotetrasiloxane with a yield of 92%.

[0054] The H NMR spectrum of the prepared 1,3,5,7-tetramethyl-1,3,5,7-tetraoctylcyclotetrasiloxane is as follows: Figure 2 As shown: 1 H NMR (400MHz, Chloroform-d) δ1.43-1.18(m,48H),0.88(t,J=6.7Hz,12H),0.53(q,J=8.5Hz,8H),0.13-0.00(m,12H).

[0055] Example 3

[0056] A method for preparing 1,3,5,7-tetramethyl-1,3,5,7-tetradecylcyclotetrasiloxane (long-chain alkylcyclotetrasiloxane), comprising the following steps:

[0057] 24g of tetramethylcyclotetrasiloxane and 50mL of n-hexane were mixed and added to a 250mL three-necked flask, and a mixed solution of 50mL of n-hexane, 40μL of Karstedt catalyst and 56.1g of 1-decene was added in batches at a stirring speed of 300r / min, and the temperature was raised to 70°C for reaction for 12h. After the reaction was completed, the filtrate was filtered, and the solvent was removed by reduced pressure distillation to obtain 1,3,5,7-tetramethyl-1,3,5,7-tetradecylcyclotetrasiloxane with a yield of 96%.

[0058] The H NMR spectrum of the prepared 1,3,5,7-tetramethyl-1,3,5,7-tetradecylcyclotetrasiloxane is as follows: Figure 3 As shown: 1 H NMR (400MHz, Chloroform-d) δ1.46-1.19 (m, 64H), 0.88 (t, J = 6.7Hz, 12H), 0.62-0.43 (m, 8H), 0.15-0.02 (m, 12H).

[0059] Example 4

[0060] A method for preparing 1,3,5,7-tetramethyl-1,3,5,7-tetradodecylcyclotetrasiloxane (long-chain alkylcyclotetrasiloxane), comprising the following steps:

[0061] 24g of tetramethylcyclotetrasiloxane and 50mL of n-hexane were mixed and added to a 250mL three-necked flask, and a mixed solution of 50mL of n-hexane, 40μL of Karstedt catalyst and 67.4g of 1-dodecene was added in batches at a stirring speed of 300r / min, and the temperature was raised to 70°C for reaction for 12h. After the reaction was completed, the filtrate was filtered, and the solvent was removed by reduced pressure distillation to obtain 1,3,5,7-tetramethyl-1,3,5,7-tetradodecylcyclotetrasiloxane with a yield of 96%.

[0062] The H NMR spectrum of the prepared 1,3,5,7-tetramethyl-1,3,5,7-tetradodecylcyclotetrasiloxane is as follows: Figure 4 As shown: 1 H NMR (400MHz, Chloroform-d) δ1.26 (s, 80H), 0.88 (t, J = 6.8Hz, 12H), 0.52 (t, J = 7.8Hz, 8H), 0.06 (s, 12H).

[0063] Example 5

[0064] A method for preparing 1,3,5,7-tetramethyl-1,3,5,7-tetratetradecylcyclotetrasiloxane (long-chain alkylcyclotetrasiloxane), comprising the following steps:

[0065] 24g of tetramethylcyclotetrasiloxane and 50mL of n-hexane were mixed and added to a 250mL three-necked flask, and a mixed solution of 50mL of n-hexane, 40μL of Karstedt catalyst and 78.5g of 1-tetradecene was added in batches at a stirring speed of 300r / min, and the temperature was raised to 70°C for reaction for 12h. After the reaction was completed, the filtrate was filtered, and the solvent was removed by reduced pressure distillation to obtain 1,3,5,7-tetramethyl-1,3,5,7-tetradecylcyclotetrasiloxane with a yield of 94%.

[0066] The H NMR spectrum of the prepared 1,3,5,7-tetramethyl-1,3,5,7-tetradecylcyclotetrasiloxane is as follows: Figure 5 As shown: 1 H NMR (400MHz, Chloroform-d) δ1.26 (s, 80H), 0.88 (t, J = 6.8Hz, 12H), 0.52 (t, J = 7.8Hz, 8H), 0.06 (s, 12H).

[0067] Example 6

[0068] A method for preparing 1,3,5,7-tetramethyl-dihexyldisiloxane comprises the following steps:

[0069] 26.8 g of tetramethyldisiloxane and 50 mL of n-hexane were mixed and added to a 250 mL three-necked flask, and a mixed solution of 50 mL of n-hexane, 40 μL of Karstedt catalyst and 50.4 g of 1-hexene was added in batches at a stirring speed of 300 r / min, and the temperature was raised to 70°C for reaction for 12 hours. After the reaction was completed, the filtrate was filtered, and the solvent was removed by reduced pressure distillation to obtain 1,3,5,7-tetramethyl-dihexyldisiloxane with a yield of 96%.

[0070] The H NMR spectrum of the prepared 1,3,5,7-tetramethyl-dihexyldisiloxane is as follows: Figure 6 As shown: 1 HNMR(400MHz,Chloroform-d)δ1.38-1.22(m,16H),0.90-0.84(m,6H),0.55-0.47(m,4H),0.06-0.05(m,12H).

[0071] Example 7

[0072] A method for preparing an alkyl-modified silicone oil single-phase immersion coolant comprises the following steps:

[0073] 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (0.1 mol) of Example 1, octamethylcyclotetrasiloxane (0.1 mol), 1,3,5,7-tetramethyl-dihexyldisiloxane (0.066 mol) of Example 6, and 0.98 g of concentrated sulfuric acid were sequentially added into a 250 mL round-bottom flask, and the temperature was raised to 100° C. to react for 12 h. After the reaction was completed, the product was filtered and distilled under reduced pressure, and the yield was 88%.

[0074] Example 8

[0075] A method for preparing an alkyl-modified silicone oil single-phase immersion coolant comprises the following steps:

[0076] 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (0.1 mol) of Example 1, octamethylcyclotetrasiloxane (0.2 mol), 1,3,5,7-tetramethyl-dihexyldisiloxane (0.066 mol) of Example 6, and 1.92 g of concentrated sulfuric acid were sequentially added into a 250 mL round-bottom flask, and the temperature was raised to 100° C. to react for 12 h. After the reaction was completed, the product was filtered and distilled under reduced pressure, and the yield was 86.2%.

[0077] The H NMR spectrum of the alkyl modified silicone oil single-phase immersion coolant prepared in this embodiment is as follows: Figure 7 As shown: 1 H NMR (400MHz, Chloroform-d) δ1.39-1.22(m,64H),0.88(td,J=7.0,1.7Hz,24H),0.56-0.44(m,16H),0.24--0.14(m,102H).

[0078] Example 9

[0079] A method for preparing an alkyl-modified silicone oil single-phase immersion coolant comprises the following steps:

[0080] 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (0.2 mol) of Example 1, octamethylcyclotetrasiloxane (0.3 mol), 1,3,5,7-tetramethyl-dihexyldisiloxane (0.066 mol) of Example 6, and 2.43 g of concentrated sulfuric acid were sequentially added into a 250 mL round-bottom flask, and the temperature was raised to 100° C. to react for 12 h. After the reaction was completed, the product was filtered and distilled under reduced pressure, and the yield was 85.1%.

[0081] Comparative Example 1

[0082] A method for preparing an alkyl-modified silicone oil single-phase immersion coolant comprises the following steps:

[0083] 0.1 mol of high hydrogen silicone oil (hydrogen content 1.56%), 0.1 mol of octamethylcyclotetrasiloxane, 0.066 mol of 1,3,5,7-tetramethyl-dihexyldisiloxane, and 0.98 g of concentrated sulfuric acid were added to a round-bottom flask in sequence, and the temperature was raised to 100°C for reaction for 12 hours. After the reaction was completed, the intermediate 1 was filtered and distilled under reduced pressure to obtain the intermediate 1 with a yield of 92.2%. Subsequently, 0.1 mol of intermediate 1 was mixed with 100 mL of n-hexane and added to a round-bottom flask, and a mixed solution of 50 mL of n-hexane, 80 μL of Karstedt catalyst and 0.75 mol of 1-hexene was added in batches at a stirring speed of 300 r / min, and the temperature was raised to 70°C for reaction for 12 hours. After the reaction was completed, it was filtered, and the filtrate was distilled under reduced pressure to remove the solvent to obtain an alkyl-modified silicone oil single-phase immersion coolant with a yield of 81.3%.

[0084] Comparative Example 2

[0085] A method for preparing an alkyl-modified silicone oil single-phase immersion coolant comprises the following steps:

[0086] 0.1mol high hydrogen silicone oil (hydrogen content 1.56%), 0.2mol octamethyltetrasiloxane, 0.066mol 1,3,5,7-tetramethyl-dihexyldisiloxane, and 1.92g concentrated sulfuric acid were added to a round-bottom flask in sequence, and the temperature was raised to 100°C for reaction for 12h. After the reaction was completed, the intermediate 2 was filtered and distilled under reduced pressure, with a yield of 89.3%. Subsequently, 0.1mol of intermediate 2 was mixed with 100mL of n-hexane and added to a round-bottom flask, and a mixed solution of 50mL of n-hexane, 80μL of Karstedt catalyst and 0.75mol of 1-hexene was added in batches at a stirring speed of 300r / min, and the temperature was raised to 70°C for reaction for 12h. After the reaction was completed, it was filtered, and the filtrate was subjected to reduced pressure distillation to remove the solvent to obtain an alkyl-modified silicone oil single-phase immersion coolant with a yield of 79.2%.

[0087] Comparative Example 3

[0088] A method for preparing an alkyl-modified silicone oil single-phase immersion coolant comprises the following steps:

[0089] 0.2 mol of high hydrogen silicone oil (hydrogen content 1.56%), 0.3 mol of octamethyltetrasiloxane, 0.066 mol of 1,3,5,7-tetramethyl-dihexyldisiloxane, and 2.43 g of concentrated sulfuric acid were added to a round-bottom flask in sequence, and the temperature was raised to 100 ° C for reaction for 12 hours. After the reaction was completed, the intermediate 3 was obtained by filtration and vacuum distillation, with a yield of 87.3%. Subsequently, 0.05 mol of intermediate 3 was mixed with 100 mL of n-hexane and added to a round-bottom flask, and a mixed solution of 50 mL of n-hexane, 80 μL of Karstedt catalyst and 0.75 mol of 1-hexene was added in batches at a stirring speed of 300 r / min, and the temperature was raised to 70 ° C for reaction for 12 hours. After the reaction was completed, it was filtered, and the filtrate was subjected to vacuum distillation to remove the solvent to obtain an alkyl-modified silicone oil single-phase immersion coolant with a yield of 77.2%.

[0090] Comparative Example 4

[0091] A method for preparing an alkyl-modified silicone oil comprises the following steps:

[0092] 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (0.1 mol), octamethylcyclotetrasiloxane (0.1 mol), hexamethyldisiloxane (0.066 mol), and 0.78 g of concentrated sulfuric acid in Example 1 were added to a 250 mL round-bottom flask in sequence, and the temperature was raised to 100° C. to react for 12 h. After the reaction was completed, excess sodium bicarbonate was added, and the product was obtained by filtration and reduced pressure distillation with a yield of 93%.

[0093] The product obtained in this example was characterized by structure (see Figure 8 ). 1 H NMR (400MHz, Chloroform-d) δ1.39-1.22(m,64H),0.88(td,J=7.0,1.7Hz,24H),0.56-0.44(m,16H),0.24--0.14(m,114H).

[0094] Comparative Example 5

[0095] A method for preparing an alkyl-modified silicone oil comprises the following steps:

[0096] 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (0.1 mol), hexamethyldisiloxane (0.066 mol), and 0.78 g of concentrated sulfuric acid in Example 1 were added to a 250 mL round-bottom flask in sequence, and the temperature was raised to 100° C. to react for 12 h. After the reaction was completed, excess sodium bicarbonate was added, and the product was obtained by filtration and reduced pressure distillation with a yield of 88.6%.

[0097] Comparative Example 6

[0098] A method for preparing an alkyl-modified silicone oil comprises the following steps:

[0099] 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (0.4 mol) of Example 1, octamethylcyclotetrasiloxane (0.6 mol), 1,3,5,7-tetramethyl-dihexyldisiloxane (0.066 mol) of Example 6, and 4.91 g of concentrated sulfuric acid were sequentially added into a round-bottom flask, and the temperature was raised to 100° C. to react for 12 hours. After the reaction was completed, the product was filtered and distilled under reduced pressure, and the yield was 83.1%.

[0100] Comparative Example 7

[0101] A method for preparing an alkyl-modified silicone oil comprises the following steps:

[0102] 1,3,5,7-tetramethyl-1,3,5,7-tetrahexylcyclotetrasiloxane (0.066 mol) of Example 1, octamethylcyclotetrasiloxane (0.066 mol) of Example 6, 1,3,5,7-tetramethyl-dihexyldisiloxane (0.066 mol) and 0.81 g of concentrated sulfuric acid were sequentially added into a round-bottom flask, and the temperature was raised to 100° C. to react for 12 hours. After the reaction was completed, the product was filtered and distilled under reduced pressure, and the yield was 85.4%.

[0103] Test Example 1

[0104] With reference to the method in the "T / FSI 102-2023" standard, the -Si-H content of the alkyl-modified silicone oils obtained in the above Examples 6-9 and Comparative Examples 1-3 was tested. The results are shown in Table 1.

[0105] Table 1

[0106]

[0107] As can be seen from Table 1, the present invention first modifies tetramethylcyclotetrasiloxane with long-chain alpha olefins to obtain long-chain alkyltetramethylcyclotetrasiloxane, and then copolymerizes long-chain alkyltetramethylcyclotetrasiloxane and octamethylcyclotetrasiloxane as monomers and 1,3,5,7-tetramethyl-dihexyldisiloxane as an end-capping agent to obtain a long-chain alkyl-terminated mono-long-chain alkyl monomethylsiloxane / dimethylsiloxane copolymer. The method of the present invention can be used to prepare a copolymer product with low steric hindrance, and the side chain alkyl and polymer structure can be accurately regulated. The obtained product will not have residual silicon-hydrogen bonds and olefins, will not form gels and elastomers, and will not explode.

[0108] Test Example 2

[0109] Referring to the method in the standard “T / SHSIC 0202-2023 Technical Indicators and Test Methods for Single-Phase Cooling Liquid in Data Center Immersion Liquid Cooling System”, the viscosity of the alkyl-modified silicone oil in Example 8 and Comparative Example 4 was characterized, and the results are shown in Table 2.

[0110] Table 2

[0111]

[0112] As can be seen from Table 2, the present invention introduces long-chain alkyl groups into the silicone oil main chain for end-capping and introduces -Si(CH3)2-O- units through molecular design to avoid entanglement of long side chains with adjacent molecules, thereby reducing intermolecular forces and thus reducing viscosity.

[0113] Test Example 3

[0114] Referring to the method in the standard "T / SHSIC 0202-2023 Technical Indicators and Test Methods for Single-Phase Cooling Liquid in Data Center Immersed Liquid Cooling System", the material compatibility of the alkyl-modified silicone oil in Example 7 and Comparative Example 5 was characterized. The results are shown in Table 1. Fig. 9 .

[0115] from Fig. 9 It can be seen that the present invention not only introduces long-chain alkyl units but also -Si(CH3)2-O- units into the main chain of silicone oil through molecular design, which not only ensures good compatibility with silicone rubber, but also has good compatibility with various rubbers such as EPDM rubber.

[0116] Test Example 4

[0117] Referring to the method in the standard "T / SHSIC 0202-2023 Technical Indicators and Test Methods for Single-Phase Cooling Liquid in Data Center Immersion Liquid Cooling System", the performance of the alkyl-modified silicone oil in Examples 7-9 was characterized, and the results are shown in Table 3:

[0118] Table 3

[0119]

[0120] It can be seen from Table 3 that the alkyl-modified silicone oil single-phase immersion coolant (the molar ratio of long-chain alkyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, and modified long-chain alkyl tetramethyldisiloxane is (1.5-3): (1.5-4.5): 1) can meet the technical indicators of the single-phase coolant of the data center immersion liquid cooling system, and can be used as the single-phase coolant of the data center immersion liquid cooling system for immersion cooling of the data center.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing an alkyl-modified silicone oil single-phase immersion coolant, characterized in that: The following steps are involved: (1) uniformly mixing tetramethylcyclotetrasiloxane and a first solvent, adding a mixed solution of a long-chain alpha olefin, a second solvent, and a catalyst, and reacting to obtain a long-chain alkylcyclotetrasiloxane; (2) uniformly mixing tetramethyldisiloxane and a first solvent, adding a mixed solution of a long-chain alpha olefin, a second solvent, and a catalyst, and reacting to obtain a modified di-long-chain alkyltetramethyldisiloxane; (3) mixing long-chain alkyl cyclotetrasiloxane, octamethylcyclotetrasiloxane, and modified long-chain alkyl tetramethyldisiloxane uniformly, adding a catalyst, and reacting to obtain an alkyl-modified silicone oil single-phase immersion coolant; The long chain alpha olefins include C6-C 14 Ene.

2. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The molar ratio of tetramethylcyclotetrasiloxane to long-chain alpha olefin in step (1) is 1:(4-5); and / or The molar ratio of tetramethyldisiloxane to long-chain alpha olefin in step (1) is 1:(2-3).

3. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The tetramethylcyclotetrasiloxane and the first solvent are used in a ratio of 1 g to (2 to 10) mL; and / or The usage ratio of the long-chain alpha olefin, the second solvent and the catalyst is 1 g: (0.5-10) mL: (0.5-5) μL.

4. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The reaction temperature in step (1) is 50-90° C. and the reaction time is 2-8 hours; and / or The reaction temperature in step (2) is 50-90° C. and the reaction time is 2-8 hours; and / or The reaction temperature in step (3) is 50-120°C and the reaction time is 10-14 hours.

5. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The tetramethyldisiloxane and the first solvent are used in a ratio of 1 g to (2-10) mL; and / or The usage ratio of the long-chain alpha olefin, the second solvent and the catalyst is 1 g: (0.5-10) mL: (0.5-5) μL.

6. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The molar ratio of the long-chain alkyl cyclotetrasiloxane, octamethyl cyclotetrasiloxane and modified long-chain alkyl tetramethyl disiloxane is (1.5-3): (1.5-4.5):

1.

7. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The amount of the catalyst used in step (3) is 0.5 to 5% of the total mass of the long-chain alkyl cyclotetrasiloxane, octamethylcyclotetrasiloxane and modified long-chain alkyl tetramethyldisiloxane.

8. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The first solvent and the second solvent independently include at least one of petroleum ether, n-hexane, ethyl acetate and toluene.

9. The method for preparing the alkyl-modified silicone oil single-phase immersion coolant according to claim 1, characterized in that: The catalyst in step (1) and step (2) comprises at least one of a Karstedt catalyst and a chloroplatinic acid catalyst; and / or The catalyst in step (3) includes at least one of concentrated sulfuric acid, trifluoromethanesulfonic acid, and solid acid.

10. Use of the alkyl-modified silicone oil single-phase immersion cooling liquid according to any one of claims 1 to 9 in immersion cooling of a data center.

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