Synthesis method of high-temperature-resistant organosilicone rubber compound structuring control agent

Abstract

The invention discloses a synthesis method of a high-temperature-resistant organosilicone rubber compound structuring control agent, and relates to the technical field of organosilicone rubber compounds. The preparation method comprises the following steps: sequentially adding octamethylcyclotetrasiloxane, a methylphenylcyclotetrasiloxane ring body and octaphenylcyclotetrasiloxane into a reaction kettle according to a preset molar ratio, and carrying out dehydration treatment under a vacuum condition to obtain a mixed ring body; respectively adding dimethyl dialkoxy silane and phenyl trialkoxy silane into the mixed ring body, and stirring until the materials are uniformly mixed, so as to obtain a siloxane ring body; heating the siloxane ring body to 90-170 DEG C, and adding a basic catalyst for reaction, so that the siloxane ring body is subjected to ring opening and alkoxy end capping; carrying out heat preservation reaction on the terminated siloxane ring body at 90-110 DEG C for 2-10 hours, and adding a neutralizer or inactivating the basic catalyst at high temperature to obtain a crude product; and adsorbing and filtering the crude product, and removing small molecules under the vacuum negative pressure condition of 140-200 DEG C to obtain the structured control agent.

Description

Technical Field

[0001] The present application relates to the technical field of organic silicon compound rubber, and in particular to a method for synthesizing a high temperature resistant organic silicon compound rubber structuring control agent. Background Art

[0002] In the preparation process of high-temperature silicone rubber compounds, structuring control agents play a vital role. The main function of structuring control agents is to optimize the processing performance of the rubber compound, ensure the uniform dispersion of fillers in the matrix, and improve the physical and chemical properties of the final product. Currently, hydroxy silicone oil has been widely used in the industry as a structuring control agent. Its advantage is that the terminal hydroxyl group can chemically react with the hydroxyl group on the surface of the filler in the rubber compound, thereby effectively enhancing the dispersion of the filler and the bonding force with the matrix.

[0003] As a polymer elastic material with both inorganic and organic properties, silicone rubber has attracted much attention due to its unique comprehensive properties. These properties include high and low temperature resistance, excellent electrical properties and chemical stability, as well as water resistance, ozone resistance and weathering resistance. High temperature vulcanized silicone rubber is an important type of silicone rubber. Its preparation process involves the mixing of high molecular weight polysiloxane (raw rubber) with reinforcing fillers, additives, vulcanizers and structural control agents, and subsequent high temperature vulcanization molding.

[0004] Although the hydroxy silicone oil reacts with the hydroxyl groups on the surface of the filler to improve the dispersion of the filler, it will also undergo condensation reaction and produce water during high-temperature mixing. Since water and silicone rubber have extremely poor compatibility, this water easily forms bubbles when it evaporates at high temperatures, thus affecting the quality and performance of the final product. Summary of the invention

[0005] The embodiment of the present application solves the technical problem in the prior art that hydroxy silicone oil will produce water at high temperature, thus affecting the quality and performance of the final product by providing a method for synthesizing a high temperature resistant silicone compound structure control agent.

[0006] The present application provides a method for synthesizing a high temperature resistant silicone rubber compound structure control agent, comprising:

[0007] S1: adding octamethylcyclotetrasiloxane, methylphenylcyclotetrasiloxane ring body and octaphenylcyclotetrasiloxane into a reaction kettle in sequence according to a preset molar ratio, and performing dehydration treatment under vacuum conditions to obtain a mixed ring body;

[0008] S2: adding dimethyldialkoxysilane and phenyltrialkoxysilane to the mixed ring body respectively, and stirring until the mixture is uniform, to obtain a siloxane ring body;

[0009] S3: heating the siloxane ring body to 90-170° C. and adding a basic catalyst to react, so as to open the siloxane ring body and cap the alkoxy groups;

[0010] S4: reacting the blocked siloxane ring at 90-110° C. for 2-10 hours, then adding a neutralizing agent or deactivating the alkaline catalyst at high temperature to obtain a crude product;

[0011] S5: After the crude product is adsorbed and filtered, small molecules are removed under vacuum negative pressure conditions of 140-200° C. to obtain a structured control agent.

[0012] In a possible implementation, the molar ratio of the octamethylcyclotetrasiloxane, the methylphenylcyclotetrasiloxane ring body and the octaphenylcyclotetrasiloxane is (10-20): (3-5): (1-3);

[0013] The molar ratio of the dimethyldialkoxysilane to the phenyltrialkoxysilane is (1.5-2):1;

[0014] The total mass ratio of the dimethyldialkoxysilane and the phenyltrialkoxysilane to the total mass of the mixed ring body is (0.2-0.4):1.

[0015] In a possible implementation, in step S1, the dehydration treatment is performed under a vacuum degree of less than 5 mbar, the dehydration temperature is 90-100° C., and the dehydration time is 1-2 hours.

[0016] In a possible implementation, the dimethyldialkoxysilane is one of dimethyldimethoxysilane, dimethyldiethoxysilane and dimethyldiacetoxysilane;

[0017] The phenyltrialkoxysilane is one of phenyltrimethoxysilane, phenyltriethoxysilane and phenyltributylacetonatoximosilane.

[0018] In a possible implementation, the alkaline catalyst is one of potassium hydroxide alkali gel, tetramethylammonium hydroxide alkali gel, phosphazene chloride, potassium hydroxide and tetramethylammonium hydroxide.

[0019] In a possible implementation, the neutralizing agent is at least one of trimethylsilyl phosphate, triethylsilyl phosphate, bistrimethylsilyl hydrogen phosphate and trimethylsilyl dihydrogen phosphate.

[0020] In a possible implementation, in step S4, the alkaline catalyst is deactivated by treating at a high temperature of 135° C. to 140° C. for 1 to 2 hours to obtain a crude product.

[0021] In a possible implementation, the viscosity of the structuring control agent is 20-100 cp.

[0022] In a possible implementation, when removing small molecules under vacuum negative pressure conditions at 140-200° C., the vacuum degree is less than 50 mbar.

[0023] In a possible implementation, the amount of the alkaline catalyst used accounts for 10-1000 ppm of the amount of the siloxane ring body used;

[0024] And / or the amount of the neutralizing agent used accounts for 100-200 ppm of the amount of the siloxane ring after end-capping.

[0025] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects:

[0026] The present application provides a method for synthesizing a high temperature resistant organic silicon compound structured control agent. In the synthetic raw materials, the introduction of methylphenyl cyclotetrasiloxane ring body and octaphenyl cyclotetrasiloxane is a key step. The methylphenyl or diphenyl group in these two raw materials effectively increases the rigidity of the molecular chain, so that the structured control agent can still maintain a stable structure under high temperature environment, and is not prone to thermal decomposition or degradation. This increase in rigidity enables the structured control agent to maintain structural stability under high temperature environment, thereby providing excellent high temperature resistance. In addition, the addition of phenyltrialkoxysilane not only further improves the high temperature resistance of the structured control agent, but also constructs a more complex interaction between molecular chains by increasing the degree of branching. The presence of this branched structure not only significantly improves the hardness of the structured control agent, but also significantly enhances its mechanical properties and compression resistance. Therefore, the structured control agent can show higher hardness and stronger load-bearing capacity in application. In order to solve the problem of bubbles formed by evaporation of water vapor in the use of hydroxy silicone oil, dimethyldialkoxysilane and phenyltrialkoxysilane are also introduced in the synthesis process of the present application. The synergistic effect of dimethyldialkoxysilane and phenyltrialkoxysilane enhances the interaction between siloxane segments, making the combination between segments tighter, thereby effectively reducing the penetration of water vapor and the formation of bubbles. This improvement not only improves the stability of the structured control agent, but also makes it more reliable during use. Therefore, the synthesis method of the high temperature resistant organosilicon compound structured control agent provided by the present application, through carefully selected synthetic raw materials and their proportions, achieves a significant improvement in the high temperature resistance, stability and reliability of the structured control agent. At the same time, by introducing dimethyldialkoxysilane and phenyltrialkoxysilane, the bubble problem that may occur in hydroxy silicone oil during use is also solved, further improving the application effect of the structured control agent. Therefore, the method has a wide range of application prospects and important practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a flow chart of a method for synthesizing a high temperature resistant silicone compound structuring control agent provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. 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 this application.

[0030] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0031] The present application provides a method for synthesizing a high temperature resistant organic silicon compound structure control agent, such as Figure 1 As shown, the synthesis method includes the following steps S1-S5:

[0032] S1: adding octamethylcyclotetrasiloxane, methylphenylcyclotetrasiloxane ring body and octaphenylcyclotetrasiloxane into a reaction kettle in sequence according to a preset molar ratio, and performing dehydration treatment under vacuum conditions to obtain a mixed ring body.

[0033] S2: Add dimethyldialkoxysilane and phenyltrialkoxysilane to the mixed ring body respectively, and stir until the mixture is uniformly mixed to obtain a siloxane ring body.

[0034] S3: The siloxane ring body is heated to 90-170° C., and an alkaline catalyst is added to react to open the siloxane ring body and cap the alkoxy groups.

[0035] S4: The blocked siloxane ring is kept at 90-110° C. for reaction for 2-10 hours, and then a neutralizing agent is added or the alkaline catalyst is deactivated at high temperature to obtain a crude product.

[0036] S5: After the crude product is adsorbed and filtered, small molecules are removed under vacuum negative pressure conditions of 140-200°C to obtain a structured control agent.

[0037] It should be noted that, in the synthesis raw materials, the introduction of methylphenylcyclotetrasiloxane ring body and octaphenylcyclotetrasiloxane is a key step. The methylphenyl or diphenyl group in these two raw materials effectively increases the rigidity of the molecular chain, so that the structured control agent can still maintain a stable structure under high temperature environment, and is not prone to thermal decomposition or degradation. The increase of this rigidity enables the structured control agent to maintain structural stability under high temperature environment, thereby providing excellent high temperature resistance. In addition, the addition of phenyltrialkoxysilane not only further improves the high temperature resistance of the structured control agent, but also constructs a more complex interaction between molecular chains by increasing the degree of branching. The existence of this branched structure not only improves the hardness of the structured control agent, but also significantly enhances its mechanical properties and compression resistance. Therefore, the structured control agent can show higher hardness and stronger load-bearing capacity in application. In order to solve the bubble problem formed by water vapor evaporation in hydroxy silicone oil in use, the present application also introduces dimethyldialkoxysilane and phenyltrialkoxysilane in the synthesis process. The synergistic effect of dimethyldialkoxysilane and phenyltrialkoxysilane makes the interaction between siloxane segments closer, thereby effectively reducing the penetration of water vapor and the formation of bubbles. This improvement not only improves the stability of the structured control agent, but also makes it more reliable during use. Therefore, the synthesis method of the high temperature resistant silicone compound structured control agent provided by the present application, through carefully selected synthetic raw materials and their proportions, achieves a significant improvement in the high temperature resistance, stability and reliability of the structured control agent. At the same time, by introducing dimethyldialkoxysilane and phenyltrialkoxysilane, the bubble problem that may occur in hydroxy silicone oil during use is also solved, further improving the application effect of the structured control agent. Therefore, the method has a wide range of application prospects and important practical value.

[0038] In the embodiment of the present application, the molar ratio of octamethylcyclotetrasiloxane, methylphenylcyclotetrasiloxane ring body and octaphenylcyclotetrasiloxane is (10-20): (3-5): (1-3). This ratio range ensures the full reaction of each raw material during the reaction process, avoiding incomplete reaction or decreased product performance caused by excess or deficiency.

[0039] The introduction of methylphenylcyclotetrasiloxane ring body and octaphenylcyclotetrasiloxane, especially their ratio to octamethylcyclotetrasiloxane, effectively adjusts the high temperature resistance and stability of the product. The presence of phenyl groups increases the rigidity of the molecular chain, so that the product can maintain a stable structure in a high temperature environment and is not prone to thermal decomposition or degradation.

[0040] The molar ratio of dimethyldialkoxysilane to phenyltrialkoxysilane is (1.5-2):1, which ensures the effective introduction of dimethyldialkoxysilane and phenyltrialkoxysilane while balancing the hardness and flexibility of the product.

[0041] The total mass ratio of dimethyldialkoxysilane and phenyltrialkoxysilane to the total mass of the mixed ring body is (0.2-0.4):1, which ensures the appropriate introduction of dimethyldialkoxysilane and phenyltrialkoxysilane, and neither the product performance will be reduced due to excessive amount nor the expected effect will not be achieved due to insufficient amount.

[0042] In the embodiment of the present application, in step S1, the dehydration treatment is carried out under the condition of a vacuum degree lower than 5mbar, the dehydration temperature is 90-100°C, and the dehydration time is 1-2 hours. The condition of a vacuum degree lower than 5mbar helps to accelerate the evaporation of water molecules, because as the vacuum degree decreases, the escape velocity of water molecules increases, thereby improving the dehydration efficiency. At the same time, the dehydration temperature of 90-100°C is selected moderately, which not only avoids the problem of raw material decomposition caused by excessively high temperature, but also ensures that the dehydration speed will not be affected by excessively low temperature. In addition, a long dehydration treatment (1-2 hours) can completely remove the moisture in the raw material, effectively reducing the bubble problem that may be caused by residual moisture during the subsequent reaction process.

[0043] In the embodiment of the present application, the dimethyldialkoxysilane is one of dimethyldimethoxysilane, dimethyldiethoxysilane and dimethyldiacetoxysilane.

[0044] In the embodiment of the present application, the phenyltrialkoxysilane is one of phenyltrimethoxysilane, phenyltriethoxysilane and phenyltributylidene oxime silane.

[0045] It should be noted that the addition of phenyltrialkoxysilane not only increases the branching degree of the product, but also significantly improves the hardness and mechanical properties of the product through the effective construction of the branched structure. Dimethyldialkoxysilane helps to improve the bubble problem formed by the evaporation of water vapor in the use of hydroxy silicone oil, and improves the stability and reliability of the product. The selection of dimethyldialkoxysilane and phenyltrialkoxysilane in the embodiment of the present application brings benefits such as chemical stability and reactivity, versatility, improved processing performance, excellent surface properties, improved product performance, a wide range of applications, and optimized formulations, reduced costs, and expanded application areas.

[0046] In the embodiment of the present application, the alkaline catalyst is one of potassium hydroxide alkali gel, tetramethylammonium hydroxide alkali gel, phosphazene chloride, potassium hydroxide and tetramethylammonium hydroxide.

[0047] In the embodiments of the present application, the neutralizing agent is at least one of trimethylsilyl phosphate, triethylsilyl phosphate, bistrimethylsilyl hydrogen phosphate and trimethylsilyl dihydrogen phosphate.

[0048] In the embodiment of the present application, in step S4, the alkaline catalyst is deactivated by treatment at a high temperature of 135° C. to 140° C. for 1 to 2 hours to obtain a crude product.

[0049] The presence of alkaline catalysts may trigger some undesirable side reactions, leading to the formation of impurities in the product. Through deactivation treatment, the occurrence of these side reactions can be reduced and the quality and stability of the product can be improved.

[0050] In the embodiment of the present application, the viscosity of the structure control agent is 20-100 cp. The structure control agent with a viscosity in the range of 20-100 cp has good fluidity and can more easily penetrate into the microstructure of silicone rubber or other materials, thereby more effectively exerting its structure control function.

[0051] In the embodiments of the present application, when small molecules are removed under vacuum negative pressure conditions at 140-200° C., the vacuum degree is lower than 50 mbar.

[0052] Under high temperature conditions, the thermal motion of small molecules intensifies and the diffusion rate accelerates, which helps small molecules escape from the material faster, thereby improving the removal efficiency.

[0053] In the embodiments of the present application, the amount of the alkaline catalyst used accounts for 10-1000ppm of the amount of the siloxane ring body. Within the range of 10-1000ppm, the alkaline catalyst can exert the best catalytic effect, promote the ring-opening polymerization reaction of the siloxane ring body, and avoid the side reactions caused by excessive alkaline catalyst.

[0054] The amount of the neutralizer and / or the neutralizer is 100-200 ppm of the amount of the blocked siloxane ring. Within the range of 100-200 ppm, the neutralizer can effectively adjust the pH value of the blocked siloxane ring to keep it within a suitable range, thereby ensuring the smooth progress of the subsequent reaction.

[0055] Embodiment 1:

[0056] 1 mol of octamethylcyclotetrasiloxane (296 g), 0.3 mol of methylphenylcyclotetrasiloxane ring body (163 g) and 0.1 mol of octaphenylcyclotetrasiloxane (79.3 g) were added to the reaction kettle in sequence, the temperature was raised to 90° C., and dehydrated for 1 hour under a vacuum of 5 mbar to obtain a mixed ring body.

[0057] 0.49 mol of dimethyldialkoxysilane (59 g) and 0.246 mol of phenyltrialkoxysilane (48.68 g) were added to the mixed ring body, and stirred until the mixture was uniformly mixed to obtain a siloxane ring body.

[0058] The siloxane ring body was heated to 100° C., and 0.019 g of tetramethylammonium hydroxide was added to react, thereby opening the siloxane ring body and capping the alkoxy groups.

[0059] The blocked siloxane ring was kept at 100°C for 4 hours and then heated to 140°C for high temperature decomposition of tetramethylammonium hydroxide to obtain a crude product.

[0060] After the crude product is filtered by adsorption, the temperature is raised to 140°C and the vacuum negative pressure is maintained at 20 mbar to remove small molecules to obtain a structured control agent.

[0061] Embodiment 2:

[0062] 2 mol of octamethylcyclotetrasiloxane, 0.5 mol of methylphenylcyclotetrasiloxane ring body and 0.3 mol of octaphenylcyclotetrasiloxane were added into the reaction kettle in sequence, the temperature was raised to 90° C., and dehydration was performed under a vacuum of 5 mbar for 1 hour to obtain a mixed ring body.

[0063] 2 mol of dimethyldialkoxysilane and 1 mol of phenyltrialkoxysilane were added to the mixed ring body respectively, and stirred until the mixture was uniformly mixed to obtain a siloxane ring body.

[0064] The siloxane ring body was heated to 100° C., and 0.046 g of tetramethylammonium hydroxide was added to react, thereby opening the siloxane ring body and capping the alkoxy groups.

[0065] The blocked siloxane ring was kept at 100°C for 4 hours and then heated to 140°C for high temperature decomposition of tetramethylammonium hydroxide to obtain a crude product.

[0066] After the crude product is filtered by adsorption, the temperature is raised to 140°C and the vacuum negative pressure is maintained at 20 mbar to remove small molecules to obtain a structured control agent.

[0067] Embodiment 3:

[0068] 1.5 mol of octamethylcyclotetrasiloxane, 0.4 mol of methylphenylcyclotetrasiloxane ring body and 0.2 mol of octaphenylcyclotetrasiloxane were added into the reaction kettle in sequence, the temperature was raised to 90° C., and dehydration was performed under a vacuum of 5 mbar for 1 hour to obtain a mixed ring body.

[0069] 1.12 mol of dimethyldialkoxysilane and 0.56 mol of phenyltrialkoxysilane were added to the mixed ring body respectively, and stirred until the mixture was uniformly mixed to obtain a siloxane ring body.

[0070] The siloxane ring body was heated to 100° C., and 0.032 g of tetramethylammonium hydroxide was added to react, thereby opening the siloxane ring body and capping the alkoxy groups.

[0071] The blocked siloxane ring was kept at 100°C for 4 hours and then heated to 140°C for high temperature decomposition of tetramethylammonium hydroxide to obtain a crude product.

[0072] After the crude product is filtered by adsorption, the temperature is raised to 140°C and the vacuum negative pressure is maintained at 20 mbar to remove small molecules to obtain a structured control agent.

[0073] Embodiment 4:

[0074] 1 mol of octamethylcyclotetrasiloxane, 0.3 mol of methylphenylcyclotetrasiloxane ring body and 0.2 mol of octaphenylcyclotetrasiloxane were added into the reaction kettle in sequence, the temperature was raised to 90° C., and dehydration was performed under a vacuum of 5 mbar for 1 hour to obtain a mixed ring body.

[0075] 0.85 mol of dimethyldialkoxysilane and 0.42 mol of phenyltrialkoxysilane were added to the mixed ring body respectively, and stirred until the mixture was uniformly mixed to obtain a siloxane ring body.

[0076] The siloxane ring body was heated to 100° C., and 0.024 g of tetramethylammonium hydroxide was added to react, thereby opening the siloxane ring body and capping the alkoxy groups.

[0077] The blocked siloxane ring was kept at 100°C for 4 hours and then heated to 140°C for high temperature decomposition of tetramethylammonium hydroxide to obtain a crude product.

[0078] After the crude product is filtered by adsorption, the temperature is raised to 140°C and the vacuum negative pressure is maintained at 20 mbar to remove small molecules to obtain a structured control agent.

[0079] Comparative Example 1:

[0080] The methylphenylsiloxane and octaphenylcyclotetrasiloxane in Example 1 were removed, and the remaining steps remained unchanged.

[0081] Comparative Example 2:

[0082] A hydroxy silicone oil with a viscosity of 50 was selected as a comparative sample.

[0083] Examples 1-4 and Comparative Examples 1-2 of the present application all use a basic high-temperature mixed rubber as the formula basis, and the specific formula is: 100 parts of raw rubber, 50 parts of precipitated silica, and 5 parts of a structured control agent. The high-temperature mixed rubber is prepared by stirring in a kneading internal mixer. Among them, the structured control agent is respectively the sample prepared in Examples 1-4 and Comparative Examples 1-2, and the test results are shown in Table 1.

[0084] Table 1 is the test results of Examples 1-4 and Comparative Examples 1-2

[0085]

[0086] As can be seen from the table, although the powder-eating time of Examples 1-4 is slightly longer than that of Comparative Example 2, it is basically the same as that of Comparative Example 1. This shows that at a lower temperature, the hydroxyl group has reacted with the surface of the powder, thereby increasing the compatibility of the powder. At the same time, although the powder-eating time of Examples 1-4 is slightly longer, the elongation at break, tensile strength and tear strength of the final product are significantly improved. This shows that in the high-temperature vulcanization stage, the hydroxyl group produced by the alkoxy group not only has a good combination with the powder, but is also more stable at high temperatures and has a better treatment effect. In addition, the final product has better transparency and a longer shelf life.

[0087] It should be noted that the powder absorbing time in this application refers to the time for absorbing the powder.

[0088] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0089] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for synthesizing a high temperature resistant silicone rubber compound structure control agent, characterized in that: include: S1: adding octamethylcyclotetrasiloxane, methylphenylcyclotetrasiloxane ring body and octaphenylcyclotetrasiloxane into a reaction kettle in sequence according to a preset molar ratio, and performing dehydration treatment under vacuum conditions to obtain a mixed ring body; S2: adding dimethyldialkoxysilane and phenyltrialkoxysilane to the mixed ring body respectively, and stirring until the mixture is uniform, to obtain a siloxane ring body; S3: heating the siloxane ring body to 90-170° C. and adding a basic catalyst to react, so as to open the siloxane ring body and cap the alkoxy groups; S4: reacting the blocked siloxane ring at 90-110° C. for 2-10 hours, then adding a neutralizing agent or deactivating the alkaline catalyst at high temperature to obtain a crude product; S5: After the crude product is adsorbed and filtered, small molecules are removed under vacuum negative pressure conditions of 140-200° C. to obtain a structured control agent.

2. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: The molar ratio of the octamethylcyclotetrasiloxane, the methylphenylcyclotetrasiloxane ring body and the octaphenylcyclotetrasiloxane is (10-20): (3-5): (1-3); The molar ratio of the dimethyldialkoxysilane to the phenyltrialkoxysilane is (1.5-2):1; The total mass ratio of the dimethyldialkoxysilane and the phenyltrialkoxysilane to the total mass of the mixed ring body is (0.2-0.4):

1.

3. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: In step S1, the dehydration treatment is carried out under the condition of a vacuum degree lower than 5 mbar, a dehydration temperature of 90-100° C., and a dehydration time of 1-2 hours.

4. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: The dimethyldialkoxysilane is one of dimethyldimethoxysilane, dimethyldiethoxysilane and dimethyldiacetoxysilane; The phenyltrialkoxysilane is one of phenyltrimethoxysilane, phenyltriethoxysilane and phenyltributylacetonatoximosilane.

5. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: The alkaline catalyst is one of potassium hydroxide alkali gel, tetramethylammonium hydroxide alkali gel, phosphazene chloride, potassium hydroxide and tetramethylammonium hydroxide.

6. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: The neutralizing agent is at least one of trimethylsilyl phosphate, triethylsilyl phosphate, bistrimethylsilyl hydrogen phosphate and trimethylsilyl dihydrogen phosphate.

7. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: In step S4, the base catalyst is deactivated by treating at a high temperature of 135° C. to 140° C. for 1 to 2 hours to obtain a crude product.

8. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: The viscosity of the structuring control agent is 20-100 cp.

9. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: When removing small molecules under vacuum negative pressure conditions at 140-200°C, the vacuum degree is less than 50mbar.

10. The method for synthesizing the high temperature resistant silicone rubber compound structure control agent according to claim 1, characterized in that: The amount of the alkaline catalyst used accounts for 10-1000ppm of the amount of the siloxane ring body used; And / or the amount of the neutralizing agent used accounts for 100-200 ppm of the amount of the siloxane ring after end-capping.

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