Radiation-aging-resistant phenyl silicone rubber compound and preparation method therefor

Abstract

Provided in the present invention is a radiation-aging-resistant phenyl silicone rubber compound, which is prepared from the following components in parts by weight: 100 parts of a phenyl silicone rubber premix, 1-3 parts of a processing aid, 20-30 parts of a radiation-resistant additive, and 0.5-2 parts of a peroxide crosslinking agent. The preparation method specifically comprises the following steps: weighing the following components according to the following parts by weight: 100 parts of the phenyl silicone rubber premix, 1-3 parts of the processing aid, 20-30 parts of the radiation-resistant additive and 0.5-2 parts of the peroxide crosslinking agent; performing first mixing on the phenyl silicone rubber premix, the processing aid and the radiation-resistant additive by using an open mill, and carrying out first tight milling to obtain a masterbatch; performing second mixing on the masterbatch and the peroxide crosslinking agent by using the open mill, and performing second tight milling to obtain a final batch; and vulcanizing the final batch to obtain the radiation-aging-resistant phenyl silicone rubber compound. The present invention solves the problem of the reduction of mechanical properties of rubber undergone ray irradiation aging in the prior art.

Description

Radiation aging-resistant phenyl silicone rubber composite and preparation method thereof Technical Field

[0001] The invention belongs to the technical field of rubber material preparation methods, and particularly relates to a phenyl silicone rubber compound resistant to radiation aging, and also relates to a preparation method of the phenyl silicone rubber compound resistant to radiation aging. Background Art

[0002] With the rapid development of nuclear power plants and space technology, more and more rubber products are being used in nuclear reactors, aerospace equipment, medical radiation protection products, and protective clothing. The interaction between high-energy radiation particles and polymer materials causes ionization and activation of rubber materials, leading to changes in the mechanical properties of the rubber composite, which in turn can cause varying degrees of damage to the performance of rubber products. This places higher demands on the radiation resistance of rubber products.

[0003] Existing silicone rubber compounds for sealing have excellent high and low temperature resistance, but poor radiation aging resistance. In particular, after γ-ray irradiation aging, the mechanical properties (tensile strength and elongation at break) of the rubber compound drop significantly.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide a phenyl silicone rubber compound resistant to radiation aging, which solves the problem in the prior art that the mechanical properties of the rubber compound decrease after radiation aging.

[0006] Another object of the present invention is to provide a method for preparing a phenyl silicone rubber composite that is resistant to radiation aging.

[0007] The technical solution adopted by the present invention is a radiation-aging-resistant phenyl silicone rubber composite, which is composed of the following components in parts by weight: 100 parts of phenyl silicone rubber premix, 1 to 3 parts of a processing aid, 20 to 30 parts of a radiation-resistant additive, and 0.5 to 2 parts of a peroxide crosslinking agent; the phenyl silicone rubber premix is ​​RBB-2060-50 silicone rubber or SR3250UDP silicone rubber.

[0008] The processing aid is 201 methyl silicone oil or KF-96 silicone oil.

[0009] The radiation-resistant additive comprises lead oxide, bismuth trioxide and gadolinium oxide. The weight ratio of lead oxide to bismuth trioxide is (3-7): (1-4), and the weight ratio of bismuth trioxide to gadolinium oxide is (1-4): (0.5-2).

[0010] The peroxide crosslinking agent is any one of 2,5-dimethyl-2,5-di-tert-butylhexylperoxide, di-tert-butylcumene peroxide or dicumyl peroxide.

[0011] Another technical solution adopted by the present invention is a method for preparing a phenyl silicone rubber composite resistant to radiation aging, which is specifically implemented according to the following steps:

[0012] Step 1: Weigh the following components according to the following weight parts: 100 parts of phenyl silicone rubber premix, 1-3 parts of processing aid, 20-30 parts of radiation-resistant additive, and 0.5-2 parts of peroxide crosslinking agent;

[0013] Step 2: Mixing the phenyl silicone rubber premix, the processing aid, and the radiation-resistant additive on an open mill for the first time and then performing a first thin pass to obtain a masterbatch;

[0014] Step 3, mixing the masterbatch and the peroxide crosslinking agent for the second time using an open mill and then performing a second thin pass to obtain a final rubber mix;

[0015] Step 4: vulcanize the final rubber mixture to obtain a phenyl silicone rubber compound resistant to radiation aging.

[0016] Another technical solution of the present invention is characterized in that: the temperature of the first mixing in step 2 is 60° C. to 80° C., and the time is 30 min to 40 min.

[0017] The temperature of the second mixing in step 3 is 40° C. to 50° C., and the time is 15 min to 20 min.

[0018] Step 4 is implemented as follows:

[0019] Step 4.1, the final rubber mix is ​​subjected to a first vulcanization in a mold using a flat vulcanizer to obtain an intermediate, wherein the first vulcanization temperature is 175° C. to 185° C., the first vulcanization time is 5 min to 10 min, and the first vulcanization pressure is 8 MPa to 12 MPa;

[0020] Step 4.2: The intermediate is subjected to a second vulcanization in a high-temperature drying oven to obtain a phenyl silicone rubber composite resistant to radiation aging. The second vulcanization is carried out by keeping the temperature at 90°C to 110°C for 1 hour to 2 hours, heating the temperature to 140°C to 160°C for 1 hour to 2 hours, and heating the temperature to 170°C to 190°C for 3 hours to 6 hours.

[0021] The beneficial effects of the present invention are:

[0022] The present invention uses phenyl silicone rubber as a material matrix and uses lead oxide, bismuth trioxide, and gadolinium oxide as radiation-resistant additives. The phenyl silicone rubber premix, processing aid, radiation-resistant additive, and peroxide crosslinking agent are uniformly mixed and then vulcanized at high temperature. The performance indicators meet the following requirements: hardness of 60±5 Shore A, tensile strength ≥7MPa, elongation at break ≥200%, and brittle temperature ≤-75°C. After aging in hot air at 200°C for 72 hours, the performance retention rate of the tensile strength and elongation at break of the rubber composite is ≥90%. After the rubber composite is placed in a gamma source radiation field for radiation aging test, the performance retention rate of the tensile strength and elongation at break of the rubber composite is ≥85%.

[0023] The phenyl silicone rubber composite prepared by the present invention has excellent low-temperature resistance and can still maintain excellent mechanical properties after being aged by gamma ray radiation, indicating that it has excellent gamma ray radiation aging resistance. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to specific embodiments.

[0025] The radiation aging resistant phenyl silicone rubber composite of the present invention is composed of the following components in parts by weight: 100 parts by weight of phenyl silicone rubber premix, 1 to 3 parts of a processing aid, 20 to 30 parts of a radiation resistant additive, and 0.5 to 2 parts of a peroxide crosslinking agent.

[0026] The phenyl silicone rubber premix is ​​RBB-2060-50 silicone rubber or SR3250UDP silicone rubber; the processing aid is 201 methyl silicone oil or KF-96 silicone oil; the radiation-resistant additives include lead oxide, bismuth trioxide and gadolinium oxide, the weight ratio of lead oxide to bismuth trioxide is (3-7): (1-4), and the weight ratio of bismuth trioxide to gadolinium oxide is (1-4): (0.5-2); the peroxide crosslinking agent is any one of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane, di-tert-butyl peroxide isopropylbenzene or diisopropylbenzene peroxide.

[0027] The present invention also provides a method for preparing a radiation-aging-resistant phenyl silicone rubber composite, which is specifically implemented according to the following steps:

[0028] Step 1: Weigh the following components according to the following weight parts: 100 parts of phenyl silicone rubber premix, 1-3 parts of processing aid, 20-30 parts of radiation-resistant additive, and 0.5-2 parts of peroxide crosslinking agent;

[0029] Step 2: The phenyl silicone rubber premix, processing aid and radiation-resistant additive are mixed for the first time using an open mill and then thinned for the first time to obtain a masterbatch; the temperature of the first mixing is 60° C. to 80° C., and the time is 30 min to 40 min.

[0030] Step 3: The masterbatch and the peroxide crosslinking agent are mixed for the second time using an open mill and then thinned for the second time to obtain a final rubber mix; the temperature of the second mixing is 40° C. to 50° C., and the time is 15 min to 20 min.

[0031] Step 4: vulcanize the final rubber mixture to obtain a phenyl silicone rubber compound resistant to radiation aging.

[0032] Step 4.1, the final rubber mix is ​​subjected to a first vulcanization in a mold using a flat vulcanizer to obtain an intermediate, wherein the first vulcanization temperature is 175° C. to 185° C., the first vulcanization time is 5 min to 10 min, and the first vulcanization pressure is 8 MPa to 12 MPa;

[0033] Step 4.2: The intermediate is subjected to a second vulcanization in a high-temperature drying oven to obtain a phenyl silicone rubber composite resistant to radiation aging. The second vulcanization is carried out by keeping the temperature at 90°C to 110°C for 1 hour to 2 hours, heating the temperature to 140°C to 160°C for 1 hour to 2 hours, and heating the temperature to 170°C to 190°C for 3 hours to 6 hours.

[0034] Example 1

[0035] The radiation aging resistant phenyl silicone rubber composite of this embodiment is composed of the following raw materials: 200 grams of RBB-2060-50 silicone rubber, 4 grams of 201 methyl silicone oil, 30 grams of lead oxide, 12 grams of bismuth trioxide, 6 grams of gadolinium oxide, and 2 grams of 2,5-dimethyl-2,5-di-tert-butyl peroxide.

[0036] The preparation method of the above embodiment comprises the following steps:

[0037] Step 1. Weigh the following raw materials according to the above materials: 200 g RBB-2060-50 silicone rubber, 4 g 201 methyl silicone oil, 30 g lead oxide, 12 g bismuth trioxide, 6 g gadolinium oxide, and 2 g 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane;

[0038] Step 2: RBB-2060-50 silicone rubber, 201 methyl silicone oil, lead oxide, bismuth trioxide, and gadolinium oxide were first mixed on an open mill and then thinned to obtain a masterbatch; the first mixing temperature was 60° C. and the mixing time was 35 min;

[0039] Step 3: Mix the masterbatch with 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane on an open mill for a second time and then perform a second thin pass to obtain a final rubber mix; the second mixing temperature is 40° C. and the time is 18 minutes;

[0040] Step 4: vulcanize the final rubber mixture to obtain a phenyl silicone rubber compound resistant to radiation aging.

[0041] Step 4.1, the final rubber mix is ​​subjected to a first vulcanization in a mold using a flat vulcanizer to obtain an intermediate, wherein the first vulcanization temperature is 180° C., the first vulcanization time is 6 min, and the first vulcanization pressure is 10 MPa;

[0042] Step 4.2: The intermediate is subjected to a second vulcanization in a high-temperature drying oven to obtain a phenyl silicone rubber composite resistant to radiation aging. The second vulcanization is carried out by keeping the temperature at 100°C for 1.5 hours, heating to 150°C for 1.5 hours, and heating to 180°C for 4 hours.

[0043] Example 2

[0044] The radiation-aging-resistant phenyl silicone rubber composite of this embodiment is composed of the following raw material components: 200 grams of RBB-2060-50 silicone rubber, 2 grams of 201 methyl silicone oil, 30 grams of lead oxide, 12 grams of bismuth trioxide, 6 grams of gadolinium oxide, and 1.6 grams of 2,5-dimethyl-2,5-di-tert-butyl peroxide.

[0045] The preparation method of the above embodiment comprises the following steps:

[0046] Step 1: According to the above raw materials, 200 g of RBB-2060-50 silicone rubber, 2 g of 201 methyl silicone oil, 30 g of lead oxide, 12 g of bismuth trioxide, 6 g of gadolinium oxide, and 1.6 g of 2,5-dimethyl-2,5-di-tert-butyl peroxide were weighed;

[0047] Step 2: RBB-2060-50 silicone rubber, 201 methyl silicone oil, lead oxide, bismuth trioxide, and gadolinium oxide were first mixed on an open mill and then thinned to obtain a masterbatch; the first mixing temperature was 60° C. and the mixing time was 35 min;

[0048] Step 3: Mix the masterbatch with 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane on an open mill for a second time and then perform a second thin pass to obtain a final rubber mix; the second mixing temperature is 40° C. and the time is 18 minutes;

[0049] Step 4: vulcanize the final rubber mixture to obtain a phenyl silicone rubber compound resistant to radiation aging.

[0050] Step 4.1, the final rubber mix is ​​subjected to a first vulcanization in a mold using a flat vulcanizer to obtain an intermediate, wherein the first vulcanization temperature is 182° C., the first vulcanization time is 8 min, and the first vulcanization pressure is 10 MPa;

[0051] Step 4.2: The intermediate is subjected to a second vulcanization in a high-temperature drying oven to obtain a phenyl silicone rubber composite resistant to radiation aging. The second vulcanization is carried out by keeping the temperature at 100°C for 1.5 hours, heating to 150°C for 1.5 hours, and heating to 180°C for 4 hours.

[0052] Example 3

[0053] The radiation-aging-resistant phenyl silicone rubber composite of this embodiment is composed of the following raw material components: 400 grams of RBB-2060-50 silicone rubber, 6 grams of 201 methyl silicone oil, 60 grams of lead oxide, 24 grams of bismuth trioxide, 12 grams of gadolinium oxide, and 3 grams of 2,5-dimethyl-2,5-di-tert-butyl peroxide.

[0054] The preparation method of the above embodiment comprises the following steps:

[0055] Step 1. Weigh the following raw materials according to the above: 400 g of RBB-2060-50 silicone rubber, 6 g of 201 methyl silicone oil, 60 g of lead oxide, 24 g of bismuth trioxide, 12 g of gadolinium oxide, and 3 g of 2,5-dimethyl-2,5-di-tert-butylperoxyhexane;

[0056] Step 2: RBB-2060-50 silicone rubber, 201 methyl silicone oil, lead oxide, bismuth trioxide, and gadolinium oxide were first mixed on an open mill and then thinned to obtain a masterbatch; the first mixing temperature was 60° C. and the mixing time was 35 min;

[0057] Step 3: Mix the masterbatch with 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane on an open mill for a second time and then perform a second thin pass to obtain a final rubber mix; the second mixing temperature is 40° C. and the time is 18 minutes;

[0058] Step 4: vulcanize the final rubber mixture to obtain a phenyl silicone rubber compound resistant to radiation aging.

[0059] Step 4.1, the final rubber mix is ​​subjected to a first vulcanization in a mold using a flat vulcanizer to obtain an intermediate, wherein the first vulcanization temperature is 180° C., the first vulcanization time is 6 min, and the first vulcanization pressure is 10 MPa;

[0060] Step 4.2: The intermediate is subjected to a second vulcanization in a high-temperature drying oven to obtain a phenyl silicone rubber composite resistant to radiation aging. The second vulcanization is carried out by keeping the temperature at 105°C for 1.2 hours, heating to 155°C for 1.4 hours, and heating to 175°C for 5 hours.

[0061] Comparative Example 1

[0062] Based on Example 1, the difference is that in the raw material composition, 200 grams of NE-151 silicone rubber is used, and RBB-2060-50 silicone rubber or SR3250UDP silicone rubber is not used.

[0063] Comparative Example 2

[0064] Based on Example 1, the difference is that: no radiation-resistant additives are added to the raw material components, and the content of lead oxide, bismuth trioxide and gadolinium oxide is 0.

[0065] The radiation aging resistant phenyl silicone rubber composites prepared in Examples 1 to 3 and Comparative Examples 1 to 2 were subjected to performance tests according to the corresponding national standards. The performance after the tests is shown in Table 1.

[0066] Table 1

[0067] The phenyl silicone rubber composites prepared in Examples 1 to 3 have performance indicators that meet the requirements of hardness 60±5 Shore A, tensile strength ≥7 MPa, elongation at break ≥200%, and brittle temperature ≤-75°C. After aging in hot air at 200°C for 72 hours, the performance retention rate of the tensile strength and elongation at break of the rubber composite is ≥90%. After the rubber composite is placed in a γ source radiation field for an irradiation aging test (unit time dose rate 0.5 Gy / s, cumulative irradiation dose 100 kGy), the performance retention rate of the tensile strength and elongation at break of the rubber composite is ≥85%.

[0068] A comparison of Example 1 and Comparative Example 1 in Table 1 reveals that, in the components of the radiation-aging-resistant phenyl silicone rubber composite, if 200 g of NE-151 silicone rubber is used without RBB-2060-50 silicone rubber or SR3250UDP silicone rubber, the composite fails the -75°C brittle temperature test, indicating that the resulting rubber composite has poor low-temperature resistance and poor radiation-aging resistance. Furthermore, after gamma-ray irradiation aging, the mechanical properties of the rubber composite significantly deteriorate.

[0069] A comparison of Example 1 and Comparative Example 2 in Table 1 reveals that, in radiation-aging-resistant phenyl silicone rubber composites, if RBB-2060-50 silicone rubber or SR3250UDP silicone rubber is used without a radiation-resistant additive, the resulting rubber composite exhibits poor radiation-aging resistance. After γ-ray irradiation aging, the mechanical properties (tensile strength and elongation at break) of the rubber composite decrease significantly. This is because the radiation-resistant additive shields and absorbs γ-rays. When the radiation enters the rubber matrix, it collides with and reacts with the radiation-resistant additive, attenuating the radiation to a certain extent. This reduces damage to the rubber's molecular structure and ultimately improves the radiation-aging resistance of the rubber composite.

[0070] The phenyl silicone rubber composite with excellent radiation aging resistance prepared by the present invention uses phenyl silicone rubber as the material matrix and uses lead oxide, bismuth trioxide, and gadolinium oxide as radiation-resistant additives. The composite is prepared by uniformly mixing a phenyl silicone rubber premix, a processing aid, a radiation-resistant additive, and a peroxide crosslinker, followed by high-temperature vulcanization. The composite exhibits excellent low-temperature resistance and maintains excellent mechanical properties after gamma-ray aging, demonstrating excellent gamma-ray aging resistance. This phenyl silicone rubber composite with excellent radiation aging resistance has broad application prospects in gamma-ray radiation environments.

Claims

1. The radiation aging resistant phenyl silicone rubber compound is composed of the following components in parts by weight: 100 parts of phenyl silicone rubber premix, 1 to 3 parts of processing aid, 20 to 30 parts of radiation-resistant additive, and 0.5 to 2 parts of peroxide crosslinking agent; the phenyl silicone rubber premix is ​​RBB-2060-50 silicone rubber or SR3250UDP silicone rubber.

2. The radiation aging resistant phenyl silicone rubber composite according to claim 1, characterized in that: The processing aid is 201 methyl silicone oil or KF-96 silicone oil.

3. The radiation aging resistant phenyl silicone rubber composite according to claim 1, characterized in that: The radiation-resistant additive comprises lead oxide, bismuth trioxide and gadolinium oxide, wherein the weight ratio of the lead oxide to the bismuth trioxide is (3-7): (1-4), and the weight ratio of the bismuth trioxide to the gadolinium oxide is (1-4): (0.5-2).

4. The radiation aging resistant phenyl silicone rubber composite according to claim 1, characterized in that: The peroxide crosslinking agent is any one of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane, di-tert-butyl peroxide isopropylbenzene or diisopropylbenzene peroxide.

5. A method for preparing a phenyl silicone rubber composite resistant to radiation aging, characterized in that: Follow the steps below to implement it: Step 1, weigh the following components according to the following weight parts: 100 parts of phenyl silicone rubber premix, 1-3 parts of processing aid, 20-30 parts of radiation-resistant additive, and 0.5-2 parts of peroxide crosslinking agent; Step 2, mixing the phenyl silicone rubber premix, processing aid and radiation-resistant additive on an open mill for the first time and then performing a first thin pass to obtain a masterbatch; Step 3, mixing the masterbatch and the peroxide crosslinking agent for a second time using an open mill, and then performing a second thin pass to obtain a final rubber mix; Step 4: vulcanizing the final rubber mixture to obtain a phenyl silicone rubber composite resistant to radiation aging.

6. The method for preparing the radiation aging resistant phenyl silicone rubber composite according to claim 5, characterized in that: In step 2, the first mixing temperature is 60° C. to 80° C., and the mixing time is 30 min to 40 min.

7. The method for preparing the radiation aging resistant phenyl silicone rubber composite according to claim 5, characterized in that: In step 3, the temperature of the second mixing is 40° C. to 50° C., and the time is 15 min to 20 min.

8. The method for preparing the radiation aging resistant phenyl silicone rubber composite according to claim 5, characterized in that: Step 4 is implemented according to the following steps: Step 4.1, subjecting the final rubber mix to a first vulcanization in a mold using a flat vulcanizer to obtain an intermediate, wherein the first vulcanization temperature is 175° C. to 185° C., the first vulcanization time is 5 min to 10 min, and the first vulcanization pressure is 8 MPa to 12 MPa; Step 4.2, subjecting the intermediate to a second vulcanization in a high-temperature drying oven to obtain a phenyl silicone rubber composite resistant to radiation aging, wherein the second vulcanization is carried out by keeping the temperature at 90°C to 110°C for 1h to 2h, heating the temperature to 140°C to 160°C for 1h to 2h, and heating the temperature to 170°C to 190°C for 3h to 6h.

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