Fluororubber / silicone rubber blend rubber and preparation method and application thereof

Abstract

The invention belongs to the technical field of materials, and particularly relates to fluororubber / silicone rubber blend rubber as well as a preparation method and application thereof. The fluororubber and the silicone rubber are blended to obtain the fluororubber / silicone rubber blended rubber, the tensile strength (greater than 15MPa) and low temperature resistance of the fluororubber and the silicone rubber are remarkably improved, advantage complementation of the fluororubber and the silicone rubber is realized, and the fluororubber / silicone rubber blended rubber has the advantages of simple preparation process, low temperature resistance, high strength and the like, and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of materials, and in particular relates to a fluororubber / silicone rubber blend and a preparation method and application thereof. Background Art

[0002] Fluororubber has the characteristics of high temperature resistance, oil resistance, and corrosion resistance. It is an indispensable sealing material for the aerospace, automotive, and shipbuilding industries. Fluororubber has a high glass transition temperature (Tg). It tends to become hard and brittle when used at low temperatures, and loses its sealing effect. In contrast, silicone rubber still maintains the elasticity and flexibility of its molecular chain even at extremely low temperatures of -90°C, and has a good low-temperature sealing effect. However, silicone rubber has poor mechanical properties. Even if it is developed for high strength, its tensile strength is usually less than 12MPa. With the development of society, it is difficult for a single fluororubber or silicone rubber to meet the diverse requirements of various applications, especially in terms of low temperature resistance and high strength. Therefore, the two rubbers are used together to prepare a fluororubber / silicone rubber blend that has the advantages of both fluororubber and silicone rubber, so that their performance is complementary, which is of great significance to further broaden the application field of rubber.

[0003] However, it is well known that the compatibility between fluororubber and silicone rubber is very poor. It is difficult to obtain a blended material with excellent performance and stability by simply blending fluororubber and silicone rubber. The commonly used method is to add nanoparticle solubilizers or use fluorinated siloxanes as modifiers to achieve the blending of fluorosilicone rubber, but the preparation process of this method is usually more complicated and the modification effect is not ideal. Patent application document CN 112646294 discloses a fluororubber / silicone rubber blend and a preparation method thereof, which improves the compatibility of fluororubber and silicone rubber. The prepared fluororubber / silicone rubber blend has the advantages of high and low temperature resistance, chemical medium resistance, and low friction coefficient; however, there are problems such as low tensile strength (about 13MPa) and a brittle temperature that can only reach -20°C. Summary of the invention

[0004] In view of the problems of the prior art, the present invention provides a fluororubber / silicone rubber blend and a preparation method and use thereof.

[0005] A fluororubber and silicone rubber blend is made from the following raw materials in parts by weight:

[0006] 1-2 parts of fluorinated diamine monomer,

[0007] 1.5-3 parts of fluorine-containing dianhydride monomer,

[0008] Silicone rubber 10-120 parts,

[0009] Reinforcing agent 10-50 parts,

[0010] Fluororubber 180-200 parts,

[0011] 6-10 parts of vulcanizing agent,

[0012] 8-16 parts of cross-linking agent.

[0013] Preferably, it is made of the following raw materials in parts by weight:

[0014] 1 part of fluorinated diamine monomer,

[0015] 1.5 parts of fluorine-containing dianhydride monomer,

[0016] 30 parts of silicone rubber,

[0017] 12 parts of reinforcing agent,

[0018] 200 parts of fluororubber,

[0019] 6 parts of vulcanizing agent,

[0020] 8 parts of crosslinking agent.

[0021] Preferably, the fluorine-containing diamine monomer is selected from 2,2-bis(trifluoromethyl)diaminobiphenyl;

[0022] And / or, the fluorine-containing dianhydride monomer is selected from 4,4-(hexafluoroisopropylene) diphthalic anhydride;

[0023] And / or, the silicone rubber raw rubber is selected from methyl vinyl silicone rubber;

[0024] and / or, the reinforcing agent is selected from fumed silica;

[0025] And / or, the fluororubber is selected from at least one of type 26 fluororubber and type 246 fluororubber;

[0026] And / or, the vulcanizing agent is selected from 2,5-di-tert-butylperoxy-2,5-dimethylhexane;

[0027] And / or, the cross-linking agent is selected from vinyl siloxane cross-linking agents.

[0028] Preferably, the crosslinking agent is selected from at least one of pentamethylpentavinylcyclopentasiloxane, tetramethyltetravinylcyclotetrasiloxane and 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane.

[0029] The present invention also provides a method for preparing the above-mentioned fluororubber and silicone rubber blend, comprising the following steps:

[0030] Step 1, dissolving a fluorine-containing dianhydride monomer and a fluorine-containing diamine monomer in a polar solvent for reaction to obtain a solution A;

[0031] Step 2, mixing solution A with raw silicone rubber, and subjecting the mixture to heat treatment to obtain silicone rubber B;

[0032] Step 3, mixing the silicone rubber B with the reinforcing agent to obtain pretreated silicone rubber powder;

[0033] Step 4, mixing the pretreated silicone rubber powder with fluororubber, a vulcanizing agent, and a crosslinking agent to obtain a fluororubber and silicone rubber blend.

[0034] Preferably, in step 1, the polar solvent is selected from N,N-dimethylformamide; the reaction time is 1-12 hours;

[0035] And / or, in step 2, the heat treatment temperature is 150-200° C., and the heat treatment time is 2-8 hours;

[0036] And / or, in step 3, the mixing time is 2-6 hours;

[0037] And / or, in step 4, the mixing temperature is 20-60° C. and the mixing time is 10-60 min.

[0038] The present invention also provides the application of the fluororubber and silicone rubber blend in the fields of automobile, aerospace, petrochemical, electronics, medical treatment and construction.

[0039] Preferably, the application is as a low-temperature resistant sealing material.

[0040] The present invention blends fluororubber and silicone rubber to obtain a fluororubber / silicone rubber blend, which significantly improves the tensile strength (greater than 15MPa) and low-temperature resistance of the fluororubber and silicone rubber, achieves complementary advantages between fluororubber and silicone rubber, has the advantages of simple preparation process, low-temperature resistance, high strength, etc., and broadens the application field of rubber.

[0041] Compared with patent application document CN 112646294, the fluororubber / silicone rubber blend prepared by the present invention has more excellent tensile strength (16.8MPa) and low brittle temperature (-62°C), and can be widely used in the fields of automobile, aerospace, petrochemical, machinery manufacturing, electronic and electrical, and medical.

[0042] Obviously, according to the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, other various forms of modification, replacement or change may be made.

[0043] The above contents of the present invention are further described in detail below through specific implementation methods in the form of embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies realized based on the above contents of the present invention belong to the scope of the present invention. DETAILED DESCRIPTION

[0044] In the following examples and experimental examples, reagents and raw materials not specifically described are all commercially available products.

[0045] Example 1 Preparation of fluororubber / silicone rubber blend

[0046] Take 1.0g of 2,2-bis(trifluoromethyl)diaminobiphenyl and 1.5g of 4,4-(hexafluoroisopropylene)diphthalic anhydride and dissolve them in 15mL of N,N-dimethylformamide (DMF) solution for 4h, blend them with 30g of methyl vinyl silicone rubber (110-2 type), place them in a 200℃ oven for 2h, take them out after cooling, and mix them with 12g of fumed silica in a kneader for 4h (due to the large size of the kneader, in order to mix better, it can be scaled up in proportion), and the pretreated silicone rubber powder can be obtained. Take all the pretreated silicone rubber powder obtained above and mix them with 200g 246 type fluororubber, 6g vulcanizing agent dipentadiene, and 8g tetramethyltetravinylcyclotetrasiloxane on an open mill for 10min, and the mixing temperature is 30℃ to prepare a fluororubber / silicone rubber blend.

[0047] Example 2 Preparation of fluororubber / silicone rubber blend

[0048] Take 1.0g of 2,2-bis(trifluoromethyl)diaminobiphenyl and 1.5g of 4,4-(hexafluoroisopropylene)diphthalic anhydride and dissolve them in 15mL of DMF solution for 4h, mix them with 60g of methyl vinyl silicone rubber, place them in a 200℃ oven for 2h, take them out after cooling and mix them with 24g of fumed silica in a kneader for 4h (due to the large size of the kneader, in order to mix better, it can be scaled up in proportion) to obtain pretreated silicone rubber powder. Take all the pretreated silicone rubber powder obtained above and mix them with 200g246 type fluororubber, 6g of vulcanizing agent dipentadienyl, and 10g of pentamethyl pentavinyl cyclopentasiloxane on an open mill for 10min, and the mixing temperature is 30℃ to prepare a fluororubber / silicone rubber blend.

[0049] Example 3 Preparation of fluororubber / silicone rubber blend

[0050] Take 2.0g of 2,2-bis(trifluoromethyl)diaminobiphenyl and 3.0g of 4,4-(hexafluoroisopropylene)diphthalic anhydride and dissolve them in 20mL of DMF solution for 4h, blend them with 90g of methyl vinyl silicone rubber, place them in a 200℃ oven for 3h, take them out after cooling, and mix them with 36g of fumed silica in a kneader for 4h (due to the large size of the kneader, it can be scaled up in proportion for better mixing) to obtain pretreated silicone rubber powder. Take all the pretreated silicone rubber powder obtained above and mix them with 200g 246 type fluororubber, 8g vulcanizing agent dipentadiene, and 12g of 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane on an open mill for 20min, and the mixing temperature is 30℃ to prepare a fluororubber / silicone rubber blend.

[0051] Example 4 Preparation of Fluororubber / Silicone Rubber Blend

[0052] Take 1.5g of 2,2-bis(trifluoromethyl)diaminobiphenyl and 2.0g of 4,4-(hexafluoroisopropylene)diphthalic anhydride and dissolve them in 20mL of DMF solution for 4h, mix them with 120g of methyl vinyl silicone rubber, place them in a 200℃ oven for 4h, take them out after cooling, and mix them with 48g of fumed silica in a kneader for 4h (due to the large size of the kneader, it can be scaled up in proportion for better mixing) to obtain pretreated silicone rubber powder. Take all the pretreated silicone rubber powder obtained above and mix them with 200g 246 type fluororubber, 10g vulcanizing agent dipentadienyl, and 16g tetramethyltetravinylcyclotetrasiloxane on an open mill for 20min, and the mixing temperature is 30℃ to prepare a fluororubber / silicone rubber blend.

[0053] The differences in the formulations of the fluororubber / silicone rubber blends of Examples 1-4 are summarized as follows (Table 1).

[0054] Table 1

[0055]

[0056]

[0057] The following is the preparation method of the control sample.

[0058] Comparative Example 1

[0059] 30g of methyl vinyl silicone rubber, 12g of fumed silica, 200g of 246 type fluororubber, 6g of vulcanizing agent dipentadienyl, and 8g of tetramethyltetravinylcyclotetrasiloxane were mixed on an open mill for 10 minutes at a mixing temperature of 30°C to prepare a fluororubber / silicone rubber blend.

[0060] Comparative Example 2

[0061] 120g of methyl vinyl silicone rubber, 48g of fumed silica, 200g of 246 type fluororubber, 10g of vulcanizing agent dipentadienyl, and 16g of tetramethyltetravinylcyclotetrasiloxane were mixed on an open mill for 20 minutes at a mixing temperature of 30°C to obtain a fluororubber / silicone rubber blend, but it was found that the silicone rubber and fluororubber could not be mixed together.

[0062] The technical solution of the present invention is further illustrated by experiments below.

[0063] Experimental Example 1 Performance Test of Fluororubber / Silicone Rubber Blends

[0064] The samples in this experimental example were prepared according to the methods of Examples 1-4 and Comparative Examples 1-2.

[0065] 1. Experimental Methods

[0066] The fluororubber / silicone rubber blend prepared above was used to prepare corresponding samples on an open mixing mill, and the samples were placed in a flat vulcanizer to prepare test pieces, and their tensile strength and elongation at break were tested according to GB / T528-2009, their density was tested according to GB / T533-2008, and their low-temperature brittleness was tested according to GB / T15256-2014.

[0067] 2. Experimental Results

[0068] The experimental results are shown in Table 2. The fluororubber / silicone rubber blend prepared in Comparative Example 2 could not be mixed together, and there was no way to perform performance testing. Compared with Comparative Example 1, the tensile strength of the fluororubber / silicone rubber blends prepared in Examples 1-4 was significantly improved, and the brittle temperature was significantly reduced, which could reach below -60°C. Among them, the tensile strength of Example 1 was the highest, which was 15.8 MPa, indicating that the fluororubber / silicone rubber blend prepared in the present invention has the advantages of low temperature resistance and high strength.

[0069] Table 2

[0070]

[0071] In summary, the present invention blends fluororubber and silicone rubber to obtain a fluororubber / silicone rubber blend, which significantly improves the tensile strength and low-temperature resistance of fluororubber and silicone rubber, achieves complementary advantages of fluororubber and silicone rubber, has the advantages of simple preparation process, low-temperature resistance, high strength, etc., and broadens the application field of rubber.

Claims

1. A fluororubber and silicone rubber blend, characterized in that: It is made of the following raw materials in parts by weight: 1-2 parts of fluorinated diamine monomer, 1.5-3 parts of fluorine-containing dianhydride monomer, Silicone rubber 10-120 parts, Reinforcing agent 10-50 parts, Fluororubber 180-200 parts, 6-10 parts of vulcanizing agent, 8-16 parts of cross-linking agent.

2. The fluororubber and silicone rubber blend according to claim 1, characterized in that: It is made of the following raw materials in parts by weight: 1 part of fluorinated diamine monomer, 1.5 parts of fluorine-containing dianhydride monomer, 30 parts of silicone rubber, 12 parts of reinforcing agent, 200 parts of fluororubber, 6 parts of vulcanizing agent, 8 parts of crosslinking agent.

3. The fluororubber and silicone rubber blend according to claim 1 or 2, characterized in that: The fluorine-containing diamine monomer is selected from 2,2-bis(trifluoromethyl)diaminobiphenyl; And / or, the fluorine-containing dianhydride monomer is selected from 4,4-(hexafluoroisopropylene) diphthalic anhydride; And / or, the silicone rubber raw rubber is selected from methyl vinyl silicone rubber; and / or, the reinforcing agent is selected from fumed silica; And / or, the fluororubber is selected from at least one of type 26 fluororubber and type 246 fluororubber; And / or, the vulcanizing agent is selected from 2,5-di-tert-butylperoxy-2,5-dimethylhexane; And / or, the cross-linking agent is selected from vinyl siloxane cross-linking agents.

4. The fluororubber and silicone rubber blend according to claim 3, characterized in that: The crosslinking agent is selected from at least one of pentamethylpentavinylcyclopentasiloxane, tetramethyltetravinylcyclotetrasiloxane and 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane.

5. The method for preparing the fluororubber and silicone rubber blend according to any one of claims 1 to 4, characterized in that: The steps include: Step 1, dissolving a fluorine-containing dianhydride monomer and a fluorine-containing diamine monomer in a polar solvent for reaction to obtain a solution A; Step 2, mixing solution A with raw silicone rubber, and subjecting the mixture to heat treatment to obtain silicone rubber B; Step 3, mixing the silicone rubber B with the reinforcing agent to obtain pretreated silicone rubber powder; Step 4, mixing the pretreated silicone rubber powder with fluororubber, a vulcanizing agent, and a crosslinking agent to obtain a fluororubber and silicone rubber blend.

6. The method for preparing a fluororubber and silicone rubber blend according to claim 5, characterized in that: In step 1, the polar solvent is selected from N,N-dimethylformamide; the reaction time is 1-12 hours; And / or, in step 2, the heat treatment temperature is 150-200° C., and the heat treatment time is 2-8 hours; And / or, in step 3, the mixing time is 2-6 hours; And / or, in step 4, the mixing temperature is 20-60° C. and the mixing time is 10-60 min.

7. Application of the fluororubber and silicone rubber blend according to any one of claims 1 to 4 in the fields of automobile, aerospace, petrochemical, electronics, medical treatment and construction.

8. The use according to claim 7, characterized in that The application is as a low temperature resistant sealing material.

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