Polyborosiloxane type damping additive for phenyl siloxane rubber as well as preparation method and application of polyborosiloxane type damping additive

Abstract

The invention belongs to the technical field of organic silicon damping materials, and particularly relates to a polyborosiloxane type damping additive for phenyl siloxane rubber as well as a preparation method and application of the polyborosiloxane type damping additive. The polyborosiloxane type damping additive for phenyl siloxane rubber is prepared from hydroxyl-terminated polysiloxane and a boron-containing aryl compound, and the hydroxyl ratio of the hydroxyl-terminated polysiloxane to the boron-containing aryl compound is 1: (0.2-3). From the perspective of molecular structure design, aryl groups are introduced into polyborosiloxane molecules, the obtained polyborosiloxane type damping additive has good compatibility with phenyl siloxane rubber, cannot be separated from the phenyl siloxane rubber, and can provide good damping performance for the phenyl siloxane rubber; the effective damping temperature range of the phenyl silicone rubber is greatly widened, and the requirement of the market for high-performance damping silicone rubber is met.

Description

Technical Field

[0001] The invention belongs to the technical field of organic silicon damping materials, and in particular relates to a polyborosiloxane damping additive for phenyl silicone rubber, and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not be necessarily regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] With the continuous advancement of science and technology, the operating speed of mechanical equipment is increasing, which leads to stronger vibrations in the working process of mechanical equipment. This vibration not only significantly reduces the accuracy, reliability and stability of the equipment, but also shortens the service life of the mechanical equipment. Therefore, controlling and eliminating vibration has become one of the important criteria for measuring the level of equipment manufacturing. Rubber damping materials can effectively reduce the vibration of mechanical equipment during operation due to their excellent vibration reduction performance, making the development of high-performance rubber damping materials an important research direction in the field of materials science.

[0004] Silicone rubber has a unique -Si-O-Si- main chain structure, which is significantly different from traditional carbon chain rubber in performance. The bond energy of Si-O-Si bond is as high as 460 kJ / mol, which is much higher than the 346 kJ / mol of CC bond. At the same time, the bond length and bond angle of Si-O-Si bond are relatively large. These structural characteristics give silicone rubber excellent resistance to high and low temperatures, radiation and UV rays. However, due to the high flexibility of silicone rubber molecular chain, its damping performance is relatively poor. In order to improve the damping performance of silicone rubber, researchers introduced large sterically hindered phenyl groups into silicone rubber, but even so, the damping performance of phenyl silicone rubber still cannot meet the application requirements of high damping. Therefore, in order to further improve the damping performance of phenyl silicone rubber, it is still necessary to modify it by adding damping additives.

[0005] Polyborosiloxane is an organosilicon polymer that introduces boron into the polysiloxane molecule. This organic-inorganic hybrid material has high bond energy BO bonds (537.6 kJ / mol) and Si-O bonds (422.5 kJ / mol), which give it excellent heat resistance and oxidation resistance, making it widely used in flame retardants, self-healing materials and impact-resistant materials. In existing patents, such as CN117467278A and CN109943076A, polyborosiloxane is added to room temperature vulcanized silicone rubber to obtain a silicone rubber composite material. However, since the matrix material is room temperature vulcanized silicone rubber, the tensile strength is less than 1MPa and the mechanical properties are poor. In addition, due to the poor compatibility of polyborosiloxane and silicone rubber, phase separation is prone to occur, resulting in the damping performance of the silicone rubber composite material being difficult to meet the needs. Summary of the invention

[0006] In order to solve the problem of poor compatibility between polyborosiloxane and phenyl silicone rubber in the prior art and easy phase separation, the present invention provides a polyborosiloxane type damping additive for phenyl silicone rubber and a preparation method and application thereof. From the perspective of molecular structure design, the present invention introduces an aromatic group into the polyborosiloxane molecule, and the obtained polyborosiloxane type damping additive has good compatibility with phenyl silicone rubber, will not phase separate from phenyl silicone rubber, and can provide phenyl silicone rubber with good damping performance, greatly broaden the effective damping temperature range of phenyl silicone rubber, and meet the market demand for high-performance damping silicone rubber.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions: In a first aspect, the present invention provides a polyborosiloxane damping additive for phenyl silicone rubber, wherein the polyborosiloxane damping additive has a number average molecular weight of 1000 to 12000 and has a structure as shown in Formula I, Formula II, Formula III or Formula IV: Formula I; Formula II; Formula III; Formula IV; In the formula, R3 is selected from one of phenyl, biphenyl and anthracene, a is selected from a positive integer from 1 to 5, b: a≤50%, and the structural formula of A is shown in V: Formula V; In the formula, R1 and R2 are independently selected from one or a combination of methyl, phenyl, vinyl and hydrogen atoms, m:n≤30%, m≤100.

[0008] Due to the introduction of boron atoms, p-π and d-π conjugation are formed in polyborosiloxane, and the dissociation and reassociation of boron oxygen dynamic bonds can effectively consume energy, and there is great potential in damping additives. However, polyborosiloxane has poor compatibility with silicone rubber and is prone to phase separation. In the present invention, boron-containing aromatic compounds containing aromatic rings are used as raw materials for constituting polyborosiloxane-type damping additives, and aromatic groups are introduced into polyborosiloxane by cross-linking boric acid with hydroxyl groups in polysiloxane. The obtained polyborosiloxane-type damping additive has good compatibility with phenyl silicone rubber, will not phase separate from phenyl silicone rubber, and can provide phenyl silicone rubber with good damping performance.

[0009] Preferably, the viscosity of the polyborosiloxane damping additive is 100-20000 mPa·s.

[0010] Preferably, the number average molecular weight of A is 1000-10000.

[0011] Preferably, R1 and R2 are both methyl.

[0012] Preferably, a is 1 or 2, and b is 1.

[0013] As the degree of polymerization of polyborosiloxane increases, the proportion of boron and aromatic groups decreases, resulting in a decrease in the performance of polyborosiloxane-type damping additives. In order to increase the boron content, the reaction temperature and time are controlled to avoid the appearance of high molecular weight polyborosiloxane.

[0014] In a second aspect, the present invention provides a method for preparing the polyborosiloxane damping additive as described in the first aspect, comprising the following steps: The terminal hydroxyl polysiloxane is mixed with an organic solvent, and then a boron-containing aromatic compound is added. After the mixture is evenly mixed, the mixture is heated for reaction to obtain a polyborosiloxane crude product. The polyborosiloxane type damping additive is obtained after rotary evaporation, dissolution, filtration, rotary evaporation and drying of the polyborosiloxane crude product.

[0015] Preferably, the hydroxyl ratio of the terminal hydroxyl polysiloxane to the boron-containing aromatic compound is 1:(0.2-3).

[0016] Preferably, the number average molecular weight of the terminal hydroxyl polysiloxane is 1000-10000, and the structural formula of the terminal hydroxyl polysiloxane is as shown in Formula VI: Formula VI.

[0017] Preferably, the boron-containing aromatic compound comprises at least one of phenylboronic acid, 1,4-phenyldiboronic acid, 1,3-phenyldiboronic acid, biphenyldiboronic acid and anthracene-9,10diboric acid.

[0018] Preferably, the reaction temperature of the heating reaction is 90° C. to 150° C., and the reaction time is 8 to 24 h.

[0019] Preferably, the organic solvent comprises at least one of toluene and xylene.

[0020] In a third aspect, the present invention provides use of the polyborosiloxane damping additive as described in the first aspect in the preparation of silicone rubber.

[0021] The beneficial effects achieved by one or more technical solutions of the present invention are as follows: (1) The polyborosiloxane type damping additive for phenyl silicone rubber prepared by the present invention has good compatibility with phenyl silicone rubber compared with other polyborosiloxanes and will not cause phase separation problems. When polyborosiloxane is introduced into phenyl silicone rubber, a boron-oxygen dynamic bond can be generated between the phenyl silicone rubber and the polyborosiloxane. In addition, the polyborosiloxane in the present invention contains aromatic groups, which can generate π-π interactions with the phenyl silicone rubber, significantly increasing the energy dissipation of the phenyl silicone rubber and improving the damping performance of the phenyl silicone rubber.

[0022] (2) The polyborosiloxane damping additive for phenyl silicone rubber prepared by the present invention has good compatibility with phenyl silicone rubber, and the high-temperature damping performance of the prepared damping silicone rubber is significantly improved. The effective damping temperature range is increased by at least 14°C, and the temperature range of tanδ>0.2 is increased by at least 179°C, without affecting the glass transition temperature of silicone rubber. It has excellent mechanical properties, the highest tensile strength reaches 5.7MPa, good fatigue resistance, and long service life, which broadens the application range of damping silicone rubber. In addition, the preparation process of the damping additive is simple, the preparation cost is low, and it is easy to be marketed.

[0023] (3) At present, the research on polyborosiloxane is mainly applied to the fields of impact-resistant materials, self-healing materials, adhesive materials, etc. The present invention utilizes the energy dissipation during the dissociation and association of the boron-oxygen dynamic bonds in polyborosiloxane to develop its application as a damping additive, and introduces phenyl groups to increase its compatibility with phenyl silicone rubber, thereby preparing a polyborosiloxane-type damping additive for phenyl silicone rubber, solving the problem of poor compatibility between polyborosiloxane and phenyl silicone rubber and broadening the application range of polyborosiloxane. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 is the dynamic mechanical (DMA) curve of the damping silicone rubber in Examples 1 to 3; Figure 2 It is the dynamic mechanical curve of the damping silicone rubber in comparative examples 1 to 4. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in combination with specific embodiments and comparative examples.

[0027] Example 1 50 g of hydroxy-terminated dimethyl polysiloxane (0.01 mol, containing 0.02 mol of hydroxyl groups) with a number average molecular weight of 5000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring. 3.66 g (0.03 mol) of phenylboric acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out. The solvent toluene was then removed by rotary evaporation, and then the product was placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane damping additive. The polyborosiloxane damping additive had a number average molecular weight of 5719 and a viscosity of 2250 mPa·s.

[0028] The raw materials were weighed in the proportion of 100 parts by weight of phenyl silicone rubber (monophenyl silicone rubber with a phenyl molar content of 30%), 50 parts by weight of white carbon black TS530, 30 parts by weight of polyborosiloxane type damping additive, and 2 parts by weight of curing agent di-2,4. The phenyl silicone rubber raw rubber was first placed in a kneader, and white carbon black TS530 was added thereto in several times. After mixing evenly at 50°C, the rubber was taken out and left to stand at room temperature for 16 hours. Then, 2 phr of curing agent di-2,4 and polyborosiloxane type damping additive were added to the open mill and mixed evenly at 30°C. Then, a vacuum vulcanizer was used for one-stage vulcanization at a vulcanization temperature of 100°C, a vulcanization time of 10 min, and a vulcanization pressure of 10 MPa. Finally, a blast oven was used for two-stage vulcanization at a condition of 180°C × 4 h to obtain the 2 mm thick damping silicone rubber required for the test.

[0029] Example 2 50 g of hydroxy-terminated dimethyl polysiloxane (0.05 mol, containing 0.1 mol of hydroxyl group) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation. The product was then placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane damping additive. The polyborosiloxane damping additive had a number average molecular weight of 1154 and a viscosity of 130 mPa·s.

[0030] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0031] Example 3 50 g of hydroxy-terminated dimethyl polysiloxane (0.05 mol, containing 0.1 mol of hydroxyl group) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring, and 8.3 g (0.05 mol) of 1,4-phenylenediboronic acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted 1,4-phenylenediboronic acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then the product was placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane damping additive. The polyborosiloxane damping additive has a number average molecular weight of 5341 and a viscosity of 3420 mPa·s.

[0032] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0033] Comparative Example 1 50 g of hydroxy-terminated dimethyl polysiloxane (0.06 mol, containing 0.12 mol of hydroxyl groups) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring. 3.1 g (0.05 mol) of boric acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, filtered to remove unreacted boric acid, and then the solvent toluene was removed by rotary evaporation. The product was then placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane product. The polyborosiloxane product was a gel-like solid with a number average molecular weight of 1198.

[0034] The polyborosiloxane product obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane product was used instead of the polyborosiloxane type damping additive.

[0035] Comparative Example 2 50 g of hydroxy-terminated dimethyl polysiloxane (0.05 mol, containing 0.1 mol of hydroxyl group) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring. 0.61 g (0.005 mol) of phenylboric acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation. The product was then placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane product. The number average molecular weight of the polyborosiloxane product was 1012 and the viscosity was 110 mPa·s.

[0036] The polyborosiloxane product obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane product was used instead of the polyborosiloxane type damping additive.

[0037] Comparative Example 3 The raw materials were weighed in the proportion of 100 parts by weight of phenyl silicone rubber (monophenyl silicone rubber with a phenyl molar content of 30%), 50 parts by weight of white carbon black TS530, and 2 parts by weight of curing agent di-2,4. The phenyl silicone rubber raw rubber was first placed in a kneader, and white carbon black TS530 was added to it in multiple times. After mixing evenly at 50°C, the rubber was taken out and left to stand at room temperature for 16 hours. Then 2 phr of curing agent di-2,4 was added to the open mill and mixed evenly at 30°C. Then, a vacuum vulcanizer was used for one-stage vulcanization. The vulcanization temperature was 100°C, the vulcanization time was 10 min, and the vulcanization pressure was 10 MPa. Finally, a blast oven was used for two-stage vulcanization. The two-stage vulcanization conditions were: 180°C×4 h, and the 2 mm thick damping silicone rubber required for the test was obtained.

[0038] Comparative Example 4 The raw materials were weighed in the proportion of 100 parts by weight of methyl silicone rubber, 50 parts by weight of white carbon black TS530, 30 parts by weight of the polyborosiloxane type damping additive of Example 1, and 2 parts by weight of the curing agent bis 2,4. First, the phenyl silicone rubber raw rubber was placed in a kneader, and white carbon black TS530 was added thereto in multiple times. After mixing evenly at 50°C, the rubber was taken out and left to stand at room temperature for 16 hours. Then, 2 phr of the curing agent bis 2,4 and the polyborosiloxane type damping additive were added to the open mill and mixed evenly at 30°C. Then, a vacuum vulcanizer was used for one-stage vulcanization, the vulcanization temperature was 100°C, the vulcanization time was 10 min, and the vulcanization pressure was 10 MPa. Finally, a blast oven was used for two-stage vulcanization, and the two-stage vulcanization conditions were: 180°C×4 h, and the 2 mm thick damping silicone rubber required for the test was obtained.

[0039] The mechanical properties and damping properties of the damping silicone rubber obtained in Examples 1 to 3 and Comparative Examples 1 to 5 were tested. The results are shown in Table 1, Table 2, Figure 1 and Figure 2 shown.

[0040] Table 1 Mechanical properties of damping silicone rubber

[0041] Table 2 Damping properties of damping silicone rubber

[0042] Compared with the polyborosiloxane product prepared using boric acid as a raw material in Comparative Example 1, the polyborosiloxane damping additive obtained in Examples 1 to 3 using a boron-containing aromatic compound containing phenyl as a raw material is similar in structure to the phenyl silicone rubber, and will not undergo obvious phase separation, and will have excellent damping performance in a wider temperature range. Compared with Comparative Example 2, the boron content of the polyborosiloxane damping additive in Examples 1 to 3 is much higher, so the damping performance of the damping silicone rubber is more excellent. In Comparative Example 4, the polyborosiloxane damping additive is added to the methyl silicone rubber. Due to the poor damping performance of the methyl silicone rubber itself and the obvious phase separation, the damping capacity of the obtained damping silicone rubber is significantly reduced, indicating that the polyborosiloxane damping additive of the present invention is a special damping additive for phenyl silicone rubber. Compared with Comparative Example 3 in which no polyborosiloxane damping additive is added, the temperature range of tanδ>0.3 and tanδ>0.2 and the loss factor of 150°C of the damping silicone rubber obtained in the embodiment are significantly improved, and it has good mechanical properties. This is because polyborosiloxane can form boron-oxygen dynamic bonds with phenyl silicone rubber. The introduction of dynamic bonds will cause dissociation and association under the dynamic strain of the damping composite material, thereby increasing energy loss, significantly improving the damping performance of phenyl silicone rubber, and widening the effective damping temperature range. The phenyl-containing polyborosiloxane is more similar in structure to phenyl silicone rubber, will not phase separate, and has better mechanical properties.

[0043] Example 4 50 g of hydroxy-terminated dimethyl polysiloxane (0.05 mol, containing 0.1 mol of hydroxyl group) with a number average molecular weight of 10000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring, and 8.3 g (0.05 mol) of 1,4-phenylenediboronic acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted 1,4-phenylenediboronic acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then the product was placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane damping additive. The polyborosiloxane damping additive had a number average molecular weight of 11770 and a viscosity of 10420 mPa·s.

[0044] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0045] Example 5 50 g of 1000 molecular weight hydroxy-terminated dimethyl polysiloxane (0.05 mol, containing 0.1 mol of hydroxyl group) and 100 mL of toluene were mixed in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring. 8.3 g (0.05 mol) of 1,3-phenylenediboronic acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted 1,4-phenylenediboronic acid was filtered out, and then the solvent toluene was removed by rotary evaporation. The product was then placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane damping additive. The polyborosiloxane damping additive has a number average molecular weight of 5412 and a viscosity of 3535 mPa·s.

[0046] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0047] Example 6 50 g of 1000 molecular weight hydroxy-terminated dimethyl polysiloxane (0.05 mol, containing 0.1 mol of hydroxyl group) and 100 mL of toluene were mixed in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring. 12.1 g (0.05 mol) of biphenyl diboric acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted 1,4-phenyl diboric acid was filtered out. The solvent toluene was then removed by rotary evaporation, and then the product was placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane damping additive. The polyborosiloxane damping additive has a number average molecular weight of 5341 and a viscosity of 3420 mPa·s.

[0048] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0049] Example 7 50 g of 1000 molecular weight hydroxy-terminated dimethyl polysiloxane (0.05 mol, containing 0.1 mol of hydroxyl group) and 100 mL of toluene were mixed in a 250 mL three-necked flask with a condensation reflux device. The flask was placed in an oil bath pot with magnetic stirring. 13.3 g (0.05 mol) of anthracene-9,10-diboric acid was slowly added under stirring at room temperature. The mixture was stirred at room temperature for 30 min, then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted 1,4-phenylenediboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation. The product was then placed in a vacuum oven at 70°C and dried for 24 h to obtain a polyborosiloxane damping additive. The polyborosiloxane damping additive has a number average molecular weight of 5821 and a viscosity of 3780 mPa·s.

[0050] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0051] Example 8 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and methylphenylsiloxane segments, with a ratio of 30% between dimethylsiloxane segments and methylphenylsiloxane segments) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0052] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0053] Example 9 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and methylvinylsiloxane segments, with a ratio of dimethylsiloxane segments to methylvinylsiloxane segments of 25%) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, then heated to 120°C, and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0054] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0055] Example 10 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and methylsiloxane segments, with a ratio of dimethylsiloxane segments to methylsiloxane segments of 20%) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0056] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0057] Embodiment 11 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and divinylsiloxane segments, with a ratio of 30% between dimethylsiloxane segments and divinylsiloxane segments) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0058] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0059] Example 12 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and vinylphenylsiloxane segments, with a ratio of 30% between dimethylsiloxane segments and vinylphenylsiloxane segments) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0060] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0061] Example 13 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and vinylsiloxane segments, with a ratio of 30% between dimethylsiloxane segments and vinylsiloxane segments) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0062] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0063] Embodiment 14 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and diphenylsiloxane segments, with a ratio of 30% between dimethylsiloxane segments and diphenylsiloxane segments) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0064] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0065] Embodiment 15 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and phenylsiloxane segments, with a ratio of 30% between dimethylsiloxane segments and phenylsiloxane segments) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring. 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C and stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0066] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0067] Example 16 50 g of hydroxy-terminated polysiloxane (composed of dimethylsiloxane segments and siloxane segments, with a ratio of 30% between dimethylsiloxane segments and siloxane segments) with a number average molecular weight of 1000 was mixed with 100 mL of toluene in a 250 mL three-necked flask with a condensation reflux device, and the flask was placed in an oil bath pot with magnetic stirring, and 1.22 g (0.01 mol) of phenylboric acid was slowly added under stirring at room temperature, stirred at room temperature for 30 min, and then heated to 120°C, stirred at 120°C for 10 h to obtain a crude product with toluene solvent. The crude product with toluene solvent was cooled to room temperature, and the unreacted phenylboric acid was filtered out, and then the solvent toluene was removed by rotary evaporation, and then placed in a vacuum oven at 70°C for 24 h to obtain a polyborosiloxane damping additive.

[0068] The polyborosiloxane damping additive obtained in this example was used to prepare the 2 mm thick damping silicone rubber required for the test. The raw material ratio and reaction conditions were the same as in Example 1 except that the polyborosiloxane damping additive was different.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A polyborosiloxane type damping additive for phenyl silicone rubber, characterized in that: The polyborosiloxane damping additive has a number average molecular weight of 1000 to 12000 and has a structure as shown in Formula I, Formula II, Formula III or Formula IV: Formula I; Formula II; Formula III; Formula IV; In the formula, R3 is selected from one of phenyl, biphenyl and anthracene, a is selected from a positive integer from 1 to 5, b: a≤50%, and the structural formula of A is shown in V: Formula V; In the formula, R1 and R2 are independently selected from one or a combination of methyl, phenyl, vinyl and hydrogen atoms, m:n≤30%, m≤100.

2. The polyborosiloxane type damping additive according to claim 1, characterized in that: The viscosity of the polyborosiloxane damping additive is 100-20000 mPa·s.

3. The polyborosiloxane type damping additive according to claim 1, characterized in that: The number average molecular weight of A is 1000~10000.

4. A method for preparing a polyborosiloxane damping additive according to any one of claims 1 to 3, characterized in that: The following steps are involved: The terminal hydroxyl polysiloxane is mixed with an organic solvent, and then a boron-containing aromatic compound is added. After the mixture is evenly mixed, the mixture is heated for reaction to obtain a polyborosiloxane crude product. The polyborosiloxane type damping additive is obtained after rotary evaporation, dissolution, filtration, rotary evaporation and drying of the polyborosiloxane crude product.

5. The preparation method according to claim 4, characterized in that: The hydroxyl ratio of the terminal hydroxyl polysiloxane to the boron-containing aromatic compound is 1:(0.2-3).

6. The preparation method according to claim 4, characterized in that: The number average molecular weight of the terminal hydroxyl polysiloxane is 1000-10000, and the structural formula of the terminal hydroxyl polysiloxane is shown in Formula IV: Formula VI.

7. The preparation method according to claim 4, characterized in that: The boron-containing aromatic compound includes at least one of phenylboric acid, 1,4-phenyldiboric acid, 1,3-phenyldiboric acid, biphenyldiboric acid and anthracene-9,10diboric acid.

8. The preparation method according to claim 4, characterized in that: The reaction temperature of the heating reaction is 90°C~150°C, and the reaction time is 8~24 h.

9. The preparation method according to claim 4, characterized in that: The organic solvent includes at least one of toluene and xylene.

10. Use of the polyborosiloxane damping additive according to any one of claims 1 to 3 in the preparation of silicone rubber.

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