Synthesis method of room-temperature vulcanized methyl phenyl silicone rubber

Abstract

The invention relates to a synthesis method of room-temperature vulcanized methyl phenyl silicone rubber, and belongs to the field of preparation of high polymer materials. The preparation method comprises the following steps: adding alpha, omega-dihydroxy polydimethyldiphenylsiloxane with high phenyl content and low polymerization degree, dimethyl cyclosiloxane and an alkaline resin catalyst into a reaction kettle, stirring, heating and reacting; after the reaction is finished, removing low-boiling-point substances in vacuum to obtain room-temperature vulcanized methyl phenyl silicone rubber; the preparation method comprises the following steps: preparing D201 ion exchange resin (quaternary ammonium salt type), 1-allyl cyclopropanesulfonyl chloride, zinc chloride, bis (1-vinyl imidazole-2-) ketone, mercaptoethyl guanidine dihydrobromide, triethylamine and dichloromethane, so as to obtain guanidine-doped D201 ion exchange resin; loading guanidine-doped D201 ion exchange resin into an ion exchange column for transformation to obtain an alkaline resin catalyst; the room-temperature vulcanized methyl phenyl silicone rubber prepared by the invention has excellent mechanical properties.

Description

Technical Field

[0001] The invention relates to the field of polymer material preparation, in particular to a method for synthesizing room temperature vulcanized methyl phenyl silicone rubber. Background Art

[0002] Silicone rubber is one of the most important products of polysiloxane. Room temperature vulcanized methyl phenyl silicone rubber has excellent weather resistance, high and low temperature resistance, damping, chemical resistance, etc., and is therefore widely used in aerospace, electronics, automotive and other fields.

[0003] Chinese patent CN101851334A: relates to the technical field of new materials and fine chemicals (special polymer materials), specifically a high temperature resistant dimethyl diphenyl room temperature vulcanized silicone rubber and its production process and use. The following four raw materials are used for synthesis, and the formula content ratio by weight is: (1) liquid dimethyl diphenyl mixed cyclosiloxane 20.0-34.0%, (2) dimethyl cyclosiloxane 65.58-79.89%, (3) water 0.10-0.40%, (4) tetramethyl ammonium hydroxide 0.008-0.015%.

[0004] Chinese patent CN111518132A: Provides a method for preparing a methylphenyl mixed ring body and a method for preparing a methylphenyl silicone rubber. The method for preparing the methylphenyl mixed ring body comprises: catalytic cracking and rearrangement of polymethylphenyl siloxane, and then gradually reducing pressure and fractionating. The method for preparing the methylphenyl silicone rubber comprises: 1) preparing a methylphenyl mixed ring body using the method for preparing a methylphenyl mixed ring body; 2) water-capping and polymerizing one or more methylphenyl mixed ring bodies obtained in step 1) with octamethylcyclosiloxane under the action of a catalyst.

[0005] Chinese patent CN111454453A: relates to a production process for preparing room temperature vulcanized phenyl silicone rubber, comprising: a polymerizing step of the reaction raw materials to polymerize the raw materials including diphenyldialkoxysilane and dimethyldialkoxysilane; a first vacuum treatment step to vacuum remove low-boiling components from the polymerized product; a second vacuum treatment step to further remove low-boiling components from the product of the first vacuum treatment, wherein the purity of the diphenyldialkoxysilane and dimethyldialkoxysilane is above 99.99%, the temperature of the first vacuum treatment is 170-190°C, the pressure is below 200Pa, and the temperature of the second vacuum treatment is below 200°C, the pressure is below 100Pa.

[0006] The mechanical properties of the room temperature vulcanized methyl phenyl silicone rubber prepared by the above patents and prior art need to be further improved. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a method for synthesizing room temperature vulcanized methyl phenyl silicone rubber, and the operation steps are as follows: S1: Add 80-100 parts by weight of α,ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization, 30-400 parts of dimethylcyclosiloxane, and 0.2-1 parts of a basic resin catalyst to a reaction kettle, and stir to heat the reaction; S2: After the reaction is completed, the low-boiling substances are removed in vacuo to obtain room temperature vulcanized methyl phenyl silicone rubber.

[0008] The dimethylcyclosiloxane is a mixture of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, wherein the content of octamethylcyclotetrasiloxane is not less than 75%.

[0009] The reaction temperature of S1 is 105-115°C and the reaction time is 4-6h.

[0010] The vacuum degree of S2 is -0.09~-0.095MPa, and the temperature is 180-190℃.

[0011] The preparation method of the high phenyl content and low polymerization degree α, ω-dihydroxy polydimethyl diphenylsiloxane is as follows: A1: Add 120-148 parts of dimethyldimethoxysilane, 180-216 parts of diphenyldihydroxysilane, and 0.01-0.02 parts of hydrochloric acid into a reaction kettle, and react at 60-80°C for 3-5 hours; A2: After the reaction is completed, add 20-30 parts of water and hydrolyze for 2-4 hours; A3: After hydrolysis, sodium hydroxide is added to adjust the pH value to neutral, and then the by-product alcohol and excess water are distilled off to obtain α, ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization.

[0012] The preparation method of the alkaline resin catalyst comprises the following steps, all calculated by weight: K1: Add 100-140 parts of D201 ion exchange resin (quaternary ammonium salt type), 1000-1200 parts of 1-allylcyclopropanesulfonyl chloride (CAS No.: 923032-59-1), and 2-5 parts of zinc chloride into a stirred tank 1, and stir and react at 30-50°C for 3-6 hours; filter, wash with water, and dry to obtain D201 ion exchange resin containing allyl groups; K2: Add 0.03-0.3 parts of bis(1-vinylimidazole-2-)ketone (CAS No.: 168322-10-9), 10-15 parts of mercaptoethylguanidine dihydrobromide (CAS No.: 32665-11-5), 2-5 parts of triethylamine, and 1000-1200 parts of dichloromethane to a stirred tank 2, and stir to react at 60-70°C for 50-100 minutes; then add 100-200 parts of allyl-containing D201 ion exchange resin, and stir to react at 60-70°C for 100-150 minutes; filter and dry to obtain guanidine-doped D201 ion exchange resin (quaternary ammonium salt type); K3: Guanidine-doped D201 ion exchange resin and sodium hydroxide are loaded into an ion exchange column for transformation to obtain hydroxide-type guanidine-doped D201 ion exchange resin (quaternary ammonium salt type), i.e., alkaline resin catalyst.

[0013] The volume of the K3 resin accounts for 25-32% of the volume of the ion exchange column; the amount of sodium hydroxide added is 2-4 times the volume of the resin, and the mass concentration of sodium hydroxide is 5-10%; the contact time is 50-100 minutes; and the forward wash flow rate is 10-20 m / h.

[0014] Reaction mechanism Bis(1-vinyl imidazole-2-)ketone undergoes a thiol-vinyl addition reaction with mercaptoethylguanidine dihydrobromide, and then continues to undergo a thiol or amino-allyl addition reaction with an allyl-containing D201 ion exchange resin to obtain a guanidine- and imidazole-loaded D201 ion exchange resin, which is then transformed to obtain a hydroxyl-type resin.

[0015] D201 ion exchange resin loaded with guanidine and imidazole groups is used as a basic catalyst, and its catalytic mechanism involves the following aspects: Guanidine and imidazole groups have strong alkalinity and can accept protons to form stable intermediates. In the hydrolysis reaction, these basic sites can attract and stabilize the protons in water molecules, making water molecules more susceptible to nucleophilic attack, thereby promoting the hydrolysis of silicon-oxygen bonds.

[0016] D201 ion exchange resin has a large specific surface area and pore structure, which helps the reactant molecules to fully contact the catalyst surface and improve the reaction efficiency. At the same time, the loaded guanidine and imidazole groups may be located at specific positions of the resin, forming a spatial configuration that is conducive to the reaction.

[0017] Synergistic effects: Guanidinium and imidazole groups may enhance the activity of the catalyst through synergistic effects. For example, one basic site may stabilize a proton in a water molecule, while the other site assists in the subsequent proton transfer or electron transfer process.

[0018] Technical Effects The present invention discloses a method for synthesizing room temperature vulcanized methyl phenyl silicone rubber. Compared with the prior art, the present invention has the following significant effects: Using D201 ion exchange resin loaded with guanidine and imidazole groups as a catalyst, efficient hydrolysis of α,ω-dihydroxy polydimethyldiphenylsiloxane and dimethylcyclosiloxane can be achieved. This catalyst not only has high catalytic activity, but also has good stability and reusability. In addition, since the catalyst is in solid form, it is easy to separate and recover from the reaction system, reducing production costs and environmental burden.

[0019] In summary, the D201 ion exchange resin loaded with guanidine and imidazole groups is used as an alkaline catalyst for the hydrolysis of α, ω-dihydroxypolydimethyldiphenylsiloxane and dimethylcyclosiloxane. This catalyst has the technical advantages of high efficiency, stability and reusability. DETAILED DESCRIPTION

[0020] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in combination with embodiments and comparative examples: Tensile strength and elongation at break: tested in accordance with GB / T528-2009. The test results are shown in Table 1.

[0021] Example 1 A method for synthesizing room temperature vulcanized methyl phenyl silicone rubber, the operating steps of which are: S1: Add 80g of α,ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization, 30g of dimethylcyclosiloxane, and 0.2g of a basic resin catalyst into a reaction kettle, and stir to heat the reaction; S2: After the reaction is completed, the low-boiling substances are removed in vacuo to obtain room temperature vulcanized methyl phenyl silicone rubber.

[0022] The dimethylcyclosiloxane is a mixture of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, wherein the content of octamethylcyclotetrasiloxane is not less than 75%.

[0023] The reaction temperature of S1 is 105°C and the reaction time is 4h.

[0024] The vacuum degree of S2 is -0.09MPa and the temperature is 180°C.

[0025] The preparation method of the high phenyl content and low polymerization degree α, ω-dihydroxy polydimethyl diphenylsiloxane is as follows: A1: Add 120g of dimethyldimethoxysilane, 180g of diphenyldihydroxysilane and 0.01g of hydrochloric acid into a reactor and react at 60°C for 3h; A2: After the reaction, add 20g of water and hydrolyze for 2h; A3: After hydrolysis, sodium hydroxide is added to adjust the pH value to neutral, and then the by-product alcohol and excess water are distilled off to obtain α, ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization.

[0026] The preparation method of the alkaline resin catalyst comprises the following steps, all calculated by weight: K1: adding 100g D201 ion exchange resin (quaternary ammonium salt type), 1000g 1-allylcyclopropanesulfonyl chloride CAS No.: 923032-59-1, and 2g zinc chloride into a stirring kettle 1, stirring and reacting at 30°C for 3 hours; filtering, washing with water, and drying to obtain D201 ion exchange resin containing allyl groups; K2: Add 0.03 g of bis(1-vinylimidazole-2-)ketone (CAS No.: 168322-10-9), 10 g of mercaptoethylguanidine dihydrobromide (CAS No.: 32665-11-5), 2 g of triethylamine, and 1000 g of dichloromethane to a stirred tank 2, and stir to react at 60° C. for 50 minutes; then add 100 g of allyl-containing D201 ion exchange resin, and stir to react at 60° C. for 100 minutes; filter and dry to obtain guanidine-doped D201 ion exchange resin (quaternary ammonium salt type); K3: Guanidine-doped D201 ion exchange resin and sodium hydroxide are loaded into an ion exchange column for transformation to obtain hydroxide-type guanidine-doped D201 ion exchange resin (quaternary ammonium salt type), i.e., alkaline resin catalyst.

[0027] The volume of the K3 resin accounts for 25% of the volume of the ion exchange column; the amount of sodium hydroxide added is twice the volume of the resin, and the mass concentration of sodium hydroxide is 5%; the contact time is 50 minutes; and the forward wash flow rate is 10 m / h.

[0028] Example 2 A method for synthesizing room temperature vulcanized methyl phenyl silicone rubber, the operating steps of which are: S1: Add 85g of α,ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization, 100g of dimethyl cyclosiloxane, and 0.4g of a basic resin catalyst into a reaction kettle, and stir to heat the reaction; S2: After the reaction is completed, the low-boiling substances are removed in vacuo to obtain room temperature vulcanized methyl phenyl silicone rubber.

[0029] The dimethylcyclosiloxane is a mixture of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, wherein the content of octamethylcyclotetrasiloxane is not less than 75%.

[0030] The reaction temperature of S1 is 110°C and the reaction time is 5h.

[0031] The vacuum degree of S2 is -0.09MPa and the temperature is 185°C.

[0032] The preparation method of the high phenyl content and low polymerization degree α, ω-dihydroxy polydimethyl diphenylsiloxane is as follows: A1: Add 130g of dimethyldimethoxysilane, 190g of diphenyldihydroxysilane and 0.015g of hydrochloric acid into a reactor and react at 65°C for 4h; A2: After the reaction, add 24g of water and hydrolyze for 3h; A3: After hydrolysis, sodium hydroxide is added to adjust the pH value to neutral, and then the by-product alcohol and excess water are distilled off to obtain α, ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization.

[0033] The preparation method of the alkaline resin catalyst comprises the following steps, all calculated by weight: K1: adding 110g D201 ion exchange resin (quaternary ammonium salt type), 1050g 1-allylcyclopropanesulfonyl chloride CAS No.: 923032-59-1, and 3g zinc chloride into a stirring kettle 1, stirring and reacting at 35°C for 4 hours; filtering, washing with water, and drying to obtain the allyl-containing D201 ion exchange resin; K2: Add 0.1 g of bis(1-vinylimidazole-2-)ketone (CAS No.: 168322-10-9), 12 g of mercaptoethylguanidine dihydrobromide (CAS No.: 32665-11-5), 3 g of triethylamine, and 1050 g of dichloromethane to a stirred tank 2, and stir to react at 65° C. for 60 minutes; then add 140 g of allyl-containing D201 ion exchange resin, and stir to react at 65° C. for 110 minutes; filter and dry to obtain guanidine-doped D201 ion exchange resin (quaternary ammonium salt type); K3: Guanidine-doped D201 ion exchange resin and sodium hydroxide are loaded into an ion exchange column for transformation to obtain hydroxide-type guanidine-doped D201 ion exchange resin (quaternary ammonium salt type), i.e., alkaline resin catalyst.

[0034] The resin volume of K3 accounts for 27% of the volume of the ion exchange column; the amount of sodium hydroxide added is 3 times the volume of the resin, and the mass concentration of sodium hydroxide is 6%; the contact time is 70 minutes; and the forward wash flow rate is 14m / h.

[0035] Example 3 A method for synthesizing room temperature vulcanized methyl phenyl silicone rubber, the operating steps of which are: S1: Add 95g of α,ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization, 300g of dimethyl cyclosiloxane, and 0.8g of a basic resin catalyst into a reaction kettle, and stir to heat the reaction; S2: After the reaction is completed, the low-boiling substances are removed in vacuo to obtain room temperature vulcanized methyl phenyl silicone rubber.

[0036] The dimethylcyclosiloxane is a mixture of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, wherein the content of octamethylcyclotetrasiloxane is not less than 75%.

[0037] The reaction temperature of S1 is 110°C and the reaction time is 5h.

[0038] The vacuum degree of S2 is -0.095MPa and the temperature is 185°C.

[0039] The preparation method of the high phenyl content and low polymerization degree α, ω-dihydroxy polydimethyl diphenylsiloxane is as follows: A1: Add 140g of dimethyldimethoxysilane, 200g of diphenyldihydroxysilane and 0.015g of hydrochloric acid into a reactor and react at 75°C for 4h; A2: After the reaction, add 28g of water and hydrolyze for 3h; A3: After hydrolysis, sodium hydroxide is added to adjust the pH value to neutral, and then the by-product alcohol and excess water are distilled off to obtain α, ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization.

[0040] The preparation method of the alkaline resin catalyst comprises the following steps, all calculated by weight: K1: adding 130g D201 ion exchange resin (quaternary ammonium salt type), 1150g 1-allylcyclopropanesulfonyl chloride CAS No.: 923032-59-1, and 4g zinc chloride into a stirring kettle 1, stirring and reacting at 45°C for 5 hours; filtering, washing with water, and drying to obtain the allyl-containing D201 ion exchange resin; K2: Add 0.2 g of bis(1-vinylimidazole-2-)ketone (CAS No.: 168322-10-9), 14 g of mercaptoethylguanidine dihydrobromide (CAS No.: 32665-11-5), 4 g of triethylamine and 1150 g of dichloromethane to stirring tank 2, and stir at 65°C for 90 minutes; then add 180 g of allyl-containing D201 ion exchange resin, and stir at 65°C for 140 minutes; filter and dry to obtain guanidine-doped D201 ion exchange resin (quaternary ammonium salt type); K3: Guanidine-doped D201 ion exchange resin and sodium hydroxide are loaded into an ion exchange column for transformation to obtain hydroxide-type guanidine-doped D201 ion exchange resin (quaternary ammonium salt type), i.e., alkaline resin catalyst.

[0041] The resin volume of K3 accounts for 30% of the volume of the ion exchange column; the amount of sodium hydroxide added is 3 times the volume of the resin, and the mass concentration of sodium hydroxide is 8%; the contact time is 90 minutes; and the forward wash flow rate is 18 m / h.

[0042] Example 4 A method for synthesizing room temperature vulcanized methyl phenyl silicone rubber, the operating steps of which are: S1: Add 100g of α,ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization, 400g of dimethyl cyclosiloxane, and 1g of a basic resin catalyst into a reaction kettle, and stir to react at elevated temperature; S2: After the reaction is completed, the low-boiling substances are removed in vacuo to obtain room temperature vulcanized methyl phenyl silicone rubber.

[0043] The dimethylcyclosiloxane is a mixture of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, wherein the content of octamethylcyclotetrasiloxane is not less than 75%.

[0044] The reaction temperature of S1 is 115°C and the reaction time is 6 hours.

[0045] The vacuum degree of S2 is -0.095MPa and the temperature is 190°C.

[0046] The preparation method of the high phenyl content and low polymerization degree α, ω-dihydroxy polydimethyl diphenylsiloxane is as follows: A1: Add 148g of dimethyldimethoxysilane, 216g of diphenyldihydroxysilane and 0.02g of hydrochloric acid into a reactor and react at 80°C for 5h; A2: After the reaction, add 30g of water and hydrolyze for 4h; A3: After hydrolysis, sodium hydroxide is added to adjust the pH value to neutral, and then the by-product alcohol and excess water are distilled off to obtain α, ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization.

[0047] The preparation method of the alkaline resin catalyst comprises the following steps, all calculated by weight: K1: adding 140g D201 ion exchange resin (quaternary ammonium salt type), 1200g 1-allylcyclopropanesulfonyl chloride CAS No.: 923032-59-1, and 5g zinc chloride into a stirring kettle 1, stirring and reacting at 50°C for 6 hours; filtering, washing with water, and drying to obtain the allyl-containing D201 ion exchange resin; K2: Add 0.3 g of bis(1-vinylimidazole-2-)ketone (CAS No.: 168322-10-9), 15 g of mercaptoethylguanidine dihydrobromide (CAS No.: 32665-11-5), 5 g of triethylamine and 1200 g of dichloromethane to a stirred tank 2, and stir at 70°C for 100 minutes; then add 200 g of allyl-containing D201 ion exchange resin, and stir at 70°C for 150 minutes; filter and dry to obtain guanidine-doped D201 ion exchange resin (quaternary ammonium salt type); K3: Guanidine-doped D201 ion exchange resin and sodium hydroxide are loaded into an ion exchange column for transformation to obtain hydroxide-type guanidine-doped D201 ion exchange resin (quaternary ammonium salt type), i.e., alkaline resin catalyst.

[0048] The volume of the K3 resin accounts for 32% of the volume of the ion exchange column; the amount of sodium hydroxide added is 4 times the volume of the resin, and the mass concentration of sodium hydroxide is 10%; the contact time is 100 minutes; and the forward wash flow rate is 20 m / h.

[0049] Comparative Example 1 No alkaline resin catalyst was added, and D201 ion exchange resin (quaternary ammonium salt type) was added. Other steps were the same as in Example 1.

[0050] Comparative Example 2 The other steps were the same as in Example 1 except that bis(1-vinylimidazole-2-)ketone was not added.

[0051] Comparative Example 3 The other steps were the same as in Example 1 except that allylcyclopropanesulfonyl chloride was not added.

[0052] Table 1 Tensile strength / Mpa Elongation at break / % Example 1 4.69 663 Example 2 4.73 671 Example 3 4.78 679 Example 4 4.85 687 Comparative Example 1 3.04 412 Comparative Example 2 4.09 584 Comparative Example 3 4.23 596 Through the data analysis of the above embodiments and comparative examples, the room temperature vulcanized methyl phenyl silicone rubber prepared by the present invention has excellent mechanical properties.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for synthesizing room temperature vulcanized methyl phenyl silicone rubber, the operating steps of which are: S1: Add 80-100 parts by weight of α,ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization, 30-400 parts of dimethylcyclosiloxane, and 0.2-1 parts of a basic resin catalyst to a reaction kettle, and stir to heat the reaction; S2: After the reaction is completed, the low-boiling substances are removed in vacuo to obtain room temperature vulcanized methyl phenyl silicone rubber; The alkaline resin is prepared by reacting and transforming D201 ion exchange resin containing allyl group, bis(1-vinyl imidazole-2-)ketone and mercaptoethylguanidine dihydrobromide.

2. The method for synthesizing room temperature vulcanized methyl phenyl silicone rubber according to claim 1, characterized in that: The dimethylcyclosiloxane is a mixture of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, wherein the content of octamethylcyclotetrasiloxane is not less than 75%.

3. The method for synthesizing room temperature vulcanized methyl phenyl silicone rubber according to claim 1, characterized in that: The reaction temperature of S1 is 105-115°C and the reaction time is 4-6h.

4. The method for synthesizing room temperature vulcanized methyl phenyl silicone rubber according to claim 1, characterized in that: The vacuum degree of S2 is -0.09~-0.095MPa, and the temperature is 180-190℃.

5. The method for synthesizing room temperature vulcanized methyl phenyl silicone rubber according to claim 1, characterized in that: The preparation method of the high phenyl content and low polymerization degree α, ω-dihydroxy polydimethyl diphenylsiloxane is as follows: A1: Add 120-148 parts of dimethyldimethoxysilane, 180-216 parts of diphenyldihydroxysilane, and 0.01-0.02 parts of hydrochloric acid into a reaction kettle, and react at 60-80°C for 3-5 hours; A2: After the reaction is completed, add 20-30 parts of water and hydrolyze for 2-4 hours; A3: After hydrolysis, sodium hydroxide is added to adjust the pH value to neutral, and then the by-product alcohol and excess water are distilled off to obtain α, ω-dihydroxy polydimethyl diphenylsiloxane with a high phenyl content and a low degree of polymerization.

6. The method for synthesizing room temperature vulcanized methyl phenyl silicone rubber according to claim 1, characterized in that: The preparation method of the basic resin catalyst, The method comprises the following steps: all calculated by weight: K1: Add 100-140 parts of D201 ion exchange resin, 1000-1200 parts of 1-allylcyclopropanesulfonyl chloride and 2-5 parts of zinc chloride into a stirred tank 1, and stir and react at 30-50° C. for 3-6 hours; filter, wash with water, and dry to obtain D201 ion exchange resin containing allyl groups; K2: Add 0.03-0.3 parts of bis(1-vinylimidazole-2-)ketone, 10-15 parts of mercaptoethylguanidine dihydrobromide, 2-5 parts of triethylamine, and 1000-1200 parts of dichloromethane to a stirred tank 2, and stir to react at 60-70° C. for 50-100 minutes; then add 100-200 parts of allyl-containing D201 ion exchange resin, and stir to react at 60-70° C. for 100-150 minutes; filter and dry to obtain guanidine-doped D201 ion exchange resin; K3: Guanidine-doped D201 ion exchange resin and sodium hydroxide are placed into an ion exchange column for transformation to obtain hydroxide-type guanidine-doped D201 ion exchange resin, i.e., alkaline resin catalyst.

7. The method for synthesizing room temperature vulcanized methyl phenyl silicone rubber according to claim 6, characterized in that: The volume of the K3 resin accounts for 25-32% of the volume of the ion exchange column; the amount of sodium hydroxide added is 2-4 times the volume of the resin, and the mass concentration of sodium hydroxide is 5-10%; the contact time is 50-100 minutes; and the forward wash flow rate is 10-20 m / h.