Damping and buffering durable rubber compound and preparation method thereof

Abstract

The invention provides a damping, buffering and durable rubber compound and a preparation method thereof, and the damping, buffering and durable rubber compound is prepared from the following components in parts by weight: 80-110 parts of polysiloxane rubber, 30-50 parts of reinforcing filler, 1-3 parts of titanate coupling agent, 1-2 parts of anti-aging agent and 5-10 parts of plasticizer. The damping and buffering durable rubber compound has good elasticity and durability, has good damping and buffering performance, can be used for manufacturing various damping and buffering materials such as damping pads, buffering blocks and springs, and can effectively reduce mechanical vibration and impact and protect safety of equipment and personnel.

Description

Technical Field

[0001] The invention relates to the technical field of rubber mixtures, and in particular to a shock-absorbing and buffering durable rubber mixture and a preparation method thereof. Background Art

[0002] As an important polymer material, rubber compound is widely used in many fields such as automobile, aerospace, electronics, and construction. Natural rubber has good elasticity, tensile strength, and wear resistance, but its aging resistance is poor; styrene-butadiene rubber has good comprehensive performance and low cost, but its elasticity and cold resistance are slightly inferior to natural rubber; butadiene rubber is known for its high elasticity, cold resistance, and wear resistance, but its tear resistance and processing performance are relatively weak. The properties of these rubber matrices lay the basic performance framework for rubber compound.

[0003] After being subjected to external forces, existing rubber compounds cannot quickly return to their original shape and show large permanent deformation. For example, in some shock-absorbing rubber products, after multiple compressions and rebounds, the rubber cannot fully recover, resulting in a gradual decrease in the shock-absorbing effect. Tensile strength and tear strength determine the resistance of rubber products when subjected to external forces; hardness affects the feel of rubber products and their coordination with other components; and elastic modulus is related to the elasticity and deformation characteristics of rubber. For example, tires require high tensile strength and tear strength to withstand the weight of the vehicle and various stresses during driving, while having appropriate hardness and elastic modulus to ensure comfort and handling. Good elasticity is an important characteristic of rubber compounds, which determines the ability of rubber products to return to their original shape after being subjected to external forces. Shock-absorbing and buffering performance is crucial for rubber products used in automotive shock absorbers, building seismic isolation pads, etc., and the rubber compounds are required to be able to effectively absorb and dissipate impact energy.

[0004] With the development of modern industry, various fields have put forward higher and higher requirements on the elasticity and shock absorption and buffering performance of rubber compounds. In the automotive industry, in order to improve the ride comfort and vehicle handling stability, high-performance shock-absorbing rubber parts are required; in the aerospace field, the demand for shock-absorbing and buffering materials that can withstand extreme environmental conditions is also increasing. However, there is still a certain gap in the existing technology in meeting these high-performance requirements, such as insufficient shock absorption performance in high-frequency vibration environments, insufficient stability of elasticity and shock absorption performance in a wide temperature range (from extremely low temperature to high temperature), etc., which has prompted further research and development of technologies to improve the elasticity and shock absorption and buffering performance of rubber compounds.

[0005] In summary, developing a rubber compound that has good elasticity, durability, and good shock-absorbing and cushioning properties is an urgent problem to be solved by the present invention. Summary of the invention

[0006] Purpose of the invention:

[0007] In view of the deficiencies in the prior art, the present invention provides a shock-absorbing and cushioning durable rubber mix and a preparation method thereof, so as to improve the elasticity, durability and shock-absorbing and cushioning performance of the rubber mix.

[0008] The technical solution of the present invention: The present invention provides a shock-absorbing and cushioning durable rubber compound, a shock-absorbing and cushioning durable rubber compound, and the components for preparing the shock-absorbing and cushioning durable rubber compound include, by weight: 80-110 parts of polysiloxane rubber, 30-50 parts of reinforcing filler, 1-3 parts of titanate coupling agent, 1-2 parts of antioxidant, and 5-10 parts of plasticizer.

[0009] Furthermore, the polysiloxane rubber is prepared by reacting high molecular weight polysiloxane, methylphenyl chlorosilane, dimethylchlorosilane, vinyltrichlorosilane, metallic sodium and toluene; the mass ratio of the high molecular weight polysiloxane, methylphenyl chlorosilane, dimethylchlorosilane and vinyltrichlorosilane is 1:5-10:12-25:10-15.

[0010] Furthermore, the preparation method of the high molecular weight polysiloxane comprises the following steps:

[0011] S1: Put 1,1,3,3-tetrachloro-1,3-disiloxane into a reaction bottle with a heating stirrer, add an appropriate amount of solvent to dissolve, and stir evenly;

[0012] S2: Slowly add a small amount of deionized water in step S1, then add sodium hydroxide, raise the temperature to 45-50°C, and stir to react for 1-2 hours;

[0013] S3: After the reaction in step S2 is completed, the reactant is dried by rotary evaporation, and then dichloromethane and polybenzimidazole are added, stirred to make the reaction clear, and the temperature is increased to 110-150° C., and stirred for reaction for 8-12 hours;

[0014] S4: After the reaction in step S3 is completed, the reaction mixture is cooled, filtered, washed and dried to obtain a high molecular weight polysiloxane.

[0015] Furthermore, the preparation method of polysiloxane rubber comprises the following steps:

[0016] SS1: weigh high molecular weight polysiloxane, methylphenyl chlorosilane, dimethyl chlorosilane, vinyl trichlorosilane, metallic sodium, and toluene and set aside;

[0017] SS2: Under nitrogen protection, the sodium metal and toluene weighed in step SS1 are added into a reaction kettle, heated to reflux state, and then the mixed solution of high molecular weight polysiloxane, methylphenyl chlorosilane, dimethyl chlorosilane and vinyl trichlorosilane weighed in step SS1 is slowly added dropwise to react, and the reaction temperature is controlled and the reaction is carried out for a period of time;

[0018] SS3: After the reaction of step SS2 is completed, the reaction product is poured into water for hydrolysis, and then the pH value is adjusted with hydrochloric acid to precipitate the product. After filtering, washing and drying, a crude polysiloxane rubber product is obtained;

[0019] SS4: The crude polysiloxane rubber product obtained in step SS3 is subjected to heat treatment at high temperature, and after the heat treatment, the product is crushed and sieved to obtain the polysiloxane rubber.

[0020] Furthermore, the reinforcing filler is a mixture of one or more of carbon black, hollow glass microspheres, and wollastonite powder.

[0021] Furthermore, the titanate coupling agent is a mixture of one or more of titanate coupling agent LD-216 and titanate coupling agent GR-201.

[0022] Furthermore, the antioxidant is a mixture of one or more of antioxidant RD, antioxidant 4010 and antioxidant H.

[0023] Furthermore, the plasticizer is polyether polyol; the weight average molecular weight of the polyether polyol is 1250-3000Da.

[0024] The present application also provides a method for preparing a shock-absorbing and cushioning durable rubber compound, comprising the following steps:

[0025] Step 1, adding polysiloxane rubber into an internal mixer, heating, starting the internal mixer, and mixing for a period of time to obtain a mixed rubber material;

[0026] Step 2: slowly add the reinforcing filler into the mixed rubber material prepared in step 1, increase the temperature, and mix for a period of time to obtain a mixed rubber preform;

[0027] Step 3: Mix the titanate coupling agent, antioxidant and plasticizer and spray them evenly on the rubber mix preform in step 2 for mixing. After mixing, pour them into a mold and cool to room temperature to obtain a shock-absorbing and durable rubber mix.

[0028] Furthermore, in step 1, the temperature of the internal mixer is 40-60°C, the stirring speed of the internal mixer is 200-250 rpm, and the mixing time is 3-5 minutes; in step 2, the mixing temperature is 100-120°C, the mixing stirring speed is 300-450 rpm, and the mixing time is 10-25 minutes; in step 3, the mixing temperature is 100-120°C, the mixing stirring speed is 300-450 rpm, and the mixing time is 1-2 minutes.

[0030] The invention discloses a shock-absorbing and buffering durable rubber compound, wherein the bond energy of the siloxane bond (Si-O) in the polysiloxane rubber is relatively high, thereby endowing the polysiloxane rubber with good thermal stability and chemical stability. This structure enables the rubber compound to resist the erosion of factors such as heat, oxygen, and chemical substances during long-term use, thereby improving durability. The molecular chain of the polysiloxane rubber has high flexibility. The rotational freedom of the siloxane bond is relatively large, and the molecular chain can be deformed under a relatively small external force, and can quickly return to its original state after the external force is removed, thereby providing the rubber compound with excellent elasticity. This elasticity is an important basis for shock-absorbing and buffering performance. When the rubber compound is impacted, the elasticity of the polysiloxane rubber can effectively absorb and store energy, and then slowly release it, thereby reducing the impact of the impact on the surrounding environment. There is a synergistic effect between the polysiloxane rubber and other components such as reinforcing fillers and plasticizers. It can provide a good attachment site for the reinforcing filler, so that the filler is better dispersed in the matrix, thereby further improving the mechanical properties and shock-absorbing and buffering performance of the rubber compound. At the same time, in combination with plasticizers, the hardness and flexibility of the rubber compound can be better adjusted, optimizing its shock-absorbing and cushioning capabilities.

[0031] Beneficial effects:

[0032] The shock-absorbing and cushioning durable rubber compound of the present invention has excellent elasticity, durability and shock-absorbing and cushioning performance. There is a synergistic effect between the polysiloxane rubber and other components such as reinforcing fillers and plasticizers, which can further improve the mechanical properties and shock-absorbing and cushioning performance of the rubber compound. DETAILED DESCRIPTION

[0033] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0034] In the following preparation examples, embodiments and comparative examples, polybenzimidazole was purchased from Shanghai Hansi Chemical Co., Ltd., CAS No. 25928-81-8; the CAS No. of vinyltrichlorosilane was 75-94-5; the CAS No. of 1,1,3,3-tetrachloro-1,3-disiloxane was 148859-49-8; titanate coupling agent LD-216 was purchased from Shanghai Luanding Industrial Co., Ltd.; titanate coupling agent GR-201 was purchased from Nanjing Tengchuan Technology Co., Ltd.; anti-aging Agent RD, antioxidant 4010, and antioxidant H were purchased from Shijiazhuang Bojian Fine Chemical Co., Ltd.; silane coupling agent KH550 was purchased from Jinan Qishang Chemical Co., Ltd.; fluorosilicone rubber was purchased from Hebei Silicon Valley Chemical Co., Ltd., and polyether polyol (weight average molecular weight of 1250Da), polyether polyol (weight average molecular weight of 3000Da), polyether polyol (weight average molecular weight of 800Da), and polyether polyol (weight average molecular weight of 3500Da) were all purchased from BASF AG.

[0035] Preparation of high molecular weight polysiloxane:

[0036] S1: Place 10 g of 1,1,3,3-tetrachloro-1,3-disiloxane in a reaction bottle with a heating stirrer, add 500 mL of tetrahydrofuran to dissolve, and stir evenly;

[0037] S2: Slowly add 0.5 g of deionized water and 2 g of sodium hydroxide in step S1, raise the temperature to 50° C., and stir to react for 2 hours;

[0038] S3: After the reaction in step S2 is completed, the reactant is dried by rotary evaporation, and then 500 mL of dichloromethane and 1 g of polybenzimidazole are added, and the reaction is stirred to make it clear, and the temperature is increased to 120° C. and stirred for 8 hours;

[0039] S4: After the reaction is completed, the reaction mixture is cooled, filtered, washed and dried to obtain the high molecular weight polysiloxane.

[0040] Preparation of polysiloxane rubber:

[0041] SS1: weigh 10 g high molecular weight polysiloxane, 80 g methylphenyl chlorosilane, 180 g dimethyl chlorosilane, 150 g vinyl chlorosilane, 500 g metallic sodium, and 2000 g toluene for later use;

[0042] SS2: Under nitrogen protection, the sodium metal and toluene weighed in step SS1 are added into the reaction kettle, heated to reflux state, and then the mixed solution of high molecular weight polysiloxane, methylphenyl chlorosilane, dimethyl chlorosilane and vinyl chlorosilane weighed in step SS1 is slowly added dropwise at a rate of 2 mL / min to react, the temperature is set to 100° C., and the reaction is carried out for 8 hours;

[0043] SS3: After the reaction of step SS2 is completed, the reaction product is poured into water for hydrolysis, and then the pH value is adjusted to 6.5 with 1 mol / L hydrochloric acid to precipitate the product, and after filtering, washing and drying, a crude polysiloxane rubber product is obtained;

[0044] SS4: The crude polysiloxane rubber product obtained in step SS3 is subjected to heat treatment at a high temperature of 180° C. for 4 hours. After the heat treatment, the product is crushed, sieved, and the like to obtain polysiloxane rubber.

[0045] The preparation method of the shock-absorbing and cushioning durable rubber compound comprises the following steps:

[0046] Step 1, adding polysiloxane rubber into an internal mixer, raising the temperature to 50° C., starting the internal mixer, stirring at a speed of 200 rpm, and internally mixing for 3 minutes to obtain a mixed rubber material;

[0047] Step 2: slowly add the reinforcing filler into the mixed rubber material prepared in step 1, raise the temperature to 100° C., stir at a speed of 400 rpm, and mix for 15 minutes to obtain a mixed rubber preform;

[0048] Step 3: Mix the titanate coupling agent, antioxidant and plasticizer and evenly spray them on the mixed rubber preform in step 2 for mixing. The mixing temperature is 100°C and the mixing stirring speed is 400 rpm. After mixing for 2 minutes, pour it into a mold and cool it to room temperature to obtain a shock-absorbing and durable mixed rubber.

[0049] Examples 1-5

[0050] According to the above-mentioned preparation method of the shock-absorbing and cushioning durable rubber compound, Table 1 is the ingredient list of the shock-absorbing and cushioning durable rubber compound of Examples 1-5 in parts by weight.

[0051] Table 1

[0052]

[0053]

[0054] Comparative Example 1

[0055] Comparative Example 1 was prepared according to the above-mentioned method for preparing the shock-absorbing and buffering durable rubber compound. The difference between this preparation and Example 2 is that the polysiloxane rubber in the internal mixer of step 1 was replaced by fluorosilicone rubber.

[0056] Comparative Example 2

[0057] Comparative Example 2 was prepared according to the above-mentioned method for preparing the shock-absorbing and cushioning durable rubber compound. The difference between this preparation and Example 2 is that the titanate coupling agent in step three is replaced by a silane coupling agent KH550.

[0058] Comparative Example 3

[0059] Comparative Example 3 was prepared according to the above-mentioned method for preparing the shock-absorbing and cushioning durable rubber compound. The difference between this preparation and Example 2 is that the polyether polyol in step 3 is replaced by tricresyl phosphate.

[0060] Performance Testing:

[0061] 1. Tensile strength: Tested according to GB / T528-2009 "Vulcanized rubber or thermoplastic rubber-Determination of tensile stress-strain properties".

[0062] 2. Elasticity test: Compression permanent deformation test: According to GB / T 7759.1-2015 "Determination of compression permanent deformation of vulcanized rubber or thermoplastic rubber Part 1: Under normal and high temperature conditions", the rubber sample is prepared into a cylindrical sample with a diameter of 5 cm and a height of 10 cm. Ensure that the surface of the sample is flat and smooth without obvious defects and impurities. The prepared sample is conditioned under standard laboratory environmental conditions at a temperature of 23°C and a relative humidity of 50% for 48 hours. The applied pressure compresses the height of the rubber sample to 75% of the original height. At a standard laboratory temperature of 23°C, the sample after the pressure is applied is placed for 48 hours, and then the compression is released. The sample is allowed to recover within 30 minutes, and the compression rate of the sample after recovery is measured to evaluate the elastic recovery performance of the rubber. Compression rate = (original height - height after recovery) / original height × 100%.

[0063] 3. Drop hammer impact test: The mixed rubber samples prepared in the embodiments and comparative examples are made into circular shock-absorbing pad samples with a diameter of 100 mm and a thickness of 20 mm. The surface of the samples should be flat and smooth, without bubbles or cracks. Three identical samples are prepared for each group of tests to ensure the reliability and repeatability of the test results. A drop hammer with a mass of 10 kg and a drop height of 2 m is selected. The drop hammer impact tester is started to allow the drop hammer to fall freely from a set height and impact the sample. During the impact, the data acquisition system collects force sensor signals and measures the induced impact force, i.e., the impact force when the sample is added. The shock-absorbing effect = (impact force when no sample is added - impact force when the sample is added) / impact force when no sample is added × 100%, wherein the impact force when no sample is added is 6260 N.

[0064] The shock-absorbing and cushioning durability mixed rubbers prepared in the embodiments and comparative examples were tested according to the above test method. The test results are shown in Table 2.

[0065] Table 2

[0066] Experimental example Tensile strength(MPa) Compression rate / % Shock absorption effect / % Example 1 30.5 4.4 82 Example 2 31.4 4.6 84 Example 3 30.8 4.3 82 Example 4 22.8 7.8 72 Example 5 26.2 8.4 70 Comparative Example 1 17.8 15.5 60 Comparative Example 2 25.4 8.7 68 Comparative Example 3 24.5 10.6 65

[0067] It can be seen from Table 1 that the shock-absorbing and cushioning durable rubber mixes prepared in Examples 1-4 have excellent tensile strength, elasticity, and shock-absorbing and cushioning properties; from the comparison between Examples 4-5 and Example 2, it can be seen that when preparing the shock-absorbing and cushioning durable rubber mix, adding a polyether polyol plasticizer with an unreasonable weight-average molecular weight will cause the tensile strength, elasticity, and shock-absorbing and cushioning properties of the prepared rubber mix to be weakened; from the comparison between Comparative Example 1 and Example 2, it can be seen that replacing the polysiloxane rubber with fluorosilicone rubber will cause the tensile strength, elasticity, and shock-absorbing and cushioning properties of the prepared rubber mix to be weakened, and the expected effect cannot be achieved; from the comparison between Comparative Example 2 and Example 2, it can be seen that replacing the titanate coupling agent with the silane coupling agent KH550 will cause the tensile strength, elasticity, and shock-absorbing and cushioning properties of the prepared rubber mix to be weakened, and the effect is not good; from the comparison between Comparative Example 3 and Example 2, it can be seen that when the polyether polyol is replaced with tricresyl phosphate, the tensile strength, elasticity, and shock-absorbing and cushioning properties of the prepared rubber mix will be weakened, and the expected effect cannot be achieved.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A shock-absorbing and durable rubber compound, characterized in that: The components for preparing the shock-absorbing and buffering durable rubber compound include, by weight: 80-110 parts of polysiloxane rubber, 30-50 parts of reinforcing filler, 1-3 parts of titanate coupling agent, 1-2 parts of antioxidant, and 5-10 parts of plasticizer.

2. A shock-absorbing and durable rubber compound according to claim 1, characterized in that: The polysiloxane rubber is prepared by reacting high molecular weight polysiloxane, methylphenyl chlorosilane, dimethylchlorosilane, vinyl trichlorosilane, metallic sodium and toluene; the mass ratio of the high molecular weight polysiloxane, methylphenyl chlorosilane, dimethylchlorosilane and vinyl trichlorosilane is 1:5-10:12-25:10-15.

3. A shock-absorbing and durable rubber compound according to claim 2, characterized in that: The preparation method of the polymer polysiloxane comprises the following steps: S1: Put 1,1,3,3-tetrachloro-1,3-disiloxane into a reaction bottle with a heating stirrer, add an appropriate amount of solvent to dissolve, and stir evenly; S2: Slowly add a small amount of deionized water in step S1, then add sodium hydroxide, raise the temperature to 45-50°C, and stir to react for 1-2 hours; S3: After the reaction in step S2 is completed, the reactant is dried by rotary evaporation, and then dichloromethane and polybenzimidazole are added, stirred to make the reaction clear, and the temperature is increased to 110-150° C., and stirred for reaction for 8-12 hours; S4: After the reaction in step S3 is completed, the reaction mixture is cooled, filtered, washed and dried to obtain a high molecular weight polysiloxane.

4. A shock-absorbing and durable rubber compound according to claim 1 or 2, characterized in that: The preparation method of the polysiloxane rubber comprises the following steps: SS1: weigh high molecular weight polysiloxane, methylphenylchlorosilane, dimethylchlorosilane, vinyltrichlorosilane, metallic sodium, and toluene and set aside; SS2: Under nitrogen protection, the sodium metal and toluene weighed in step SS1 are added into a reaction kettle, heated to reflux state, and then the mixed solution of high molecular weight polysiloxane, methylphenyl chlorosilane, dimethyl chlorosilane and vinyl trichlorosilane weighed in step SS1 is slowly added dropwise to react, and the reaction temperature is controlled and the reaction is carried out for a period of time; SS3: After the reaction of step SS2 is completed, the reaction product is poured into water for hydrolysis, and then the pH value is adjusted with hydrochloric acid to precipitate the product. After filtering, washing and drying, a crude polysiloxane rubber product is obtained; SS4: The crude polysiloxane rubber product obtained in step SS3 is subjected to heat treatment at high temperature, and after the heat treatment, the product is crushed and sieved to obtain the polysiloxane rubber.

5. The shock-absorbing and cushioning durable rubber compound according to claim 1, characterized in that: The reinforcing filler is a mixture of one or more of carbon black, hollow glass microspheres and wollastonite powder.

6. The shock-absorbing and cushioning durable rubber compound according to claim 1, characterized in that: The titanate coupling agent is a mixture of one or more of titanate coupling agent LD-216 and titanate coupling agent GR-201.

7. The shock-absorbing and cushioning durable rubber compound according to claim 1, characterized in that: The antioxidant is a mixture of one or more of antioxidant RD, antioxidant 4010 and antioxidant H.

8. The shock-absorbing and cushioning durable rubber compound according to claim 1, characterized in that: The plasticizer is polyether polyol; the weight average molecular weight of the polyether polyol is 1250-3000Da.

9. A method for preparing the shock-absorbing and cushioning durable rubber compound according to any one of claims 1 to 8, comprising the following steps: Step 1, adding polysiloxane rubber into an internal mixer, heating, starting the internal mixer, and mixing for a period of time to obtain a mixed rubber material; Step 2: slowly add the reinforcing filler into the mixed rubber material prepared in step 1, increase the temperature, and mix for a period of time to obtain a mixed rubber preform; Step 3: Mix the titanate coupling agent, antioxidant and plasticizer and spray them evenly on the rubber mix preform in step 2 for mixing. After mixing, pour them into a mold and cool to room temperature to obtain a shock-absorbing and durable rubber mix.

10. The method for preparing a shock-absorbing and durable rubber compound according to claim 9, characterized in that: In the first step, the temperature of the internal mixer is 40-60°C, the stirring speed of the internal mixer is 200-250 rpm, and the mixing time is 3-5 minutes; in the second step, the mixing temperature is 100-120°C, the mixing stirring speed is 300-450 rpm, and the mixing time is 10-25 minutes; in the third step, the mixing temperature is 100-120°C, the mixing stirring speed is 300-450 rpm, and the mixing time is 1-2 minutes.

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