CN117659228A - A kind of amine oxime functionalized nitrile rubber and its preparation method and application - Google Patents

Abstract

The invention discloses an amidoxime functionalized nitrile rubber and its preparation method and application, and relates to the technical field of rubber. The functionalization degree of the amidoxime functionalized nitrile rubber is 2-15%. In the present invention, after the nitrile rubber is functionally modified with an oxime, a "covalent" cross-linked network formed by self-crosslinking, a hydrogen-bonded cross-linked network formed by intermolecular "hydrogen bonds", and a "covalent" cross-linked network formed by coordination interaction are used. "bit bond" cross-linked network to prepare rubber materials with self-cross-linking and self-reinforcement. Without the addition of cross-linking agents and reinforcing agents, this cross-linking system only utilizes the self-cross-linking effect of its own amine oxime bond, hydrogen bonding effect and coordination effect with metal ions. This cross-linking system is green and environmentally friendly, and the vulcanization process is No unpleasant pungent odor will be produced in the rubber. At the same time, the use of "hydrogen bonds" and "coordination bonds" will dissipate a large amount of energy during the rupture and reorganization process to achieve self-reinforcement and toughening of the rubber.

Description

A kind of amine oxime functionalized nitrile rubber and its preparation method and application

Technical field

The present invention relates to the technical field of rubber, and more specifically, to an amidoxime functionalized nitrile rubber and its preparation method and application.

Background technique

Nitrile rubber (NBR) is obtained by emulsion polymerization of butadiene and acrylonitrile. The nitrile group (-CN) has relatively large polarity, which makes NBR have good oil resistance and damping properties, so it is widely used in Various damping materials are being prepared. At present, NBR still widely uses sulfur and peroxide for vulcanization. The accelerator used will discharge high-concentration organic wastewater during the synthesis process and faces the problem of refractory degradation. At the same time, carcinogen nitrosamines will be generated during the high-temperature vulcanization process. , causing environmental pollution; some dust will inevitably be generated during the processing process, accompanied by the release of toxic volatile organic molecules (VOCs), which has an unpleasant odor, poses a threat to human life and health, and brings problems to users. Uncomfortable use experience.

When the service life of rubber products ends, the problem of black pollution caused by waste rubber becomes increasingly serious. Approximately 800 million tires are discarded every year, and this number is rising rapidly at a rate of 2% every year. Since most of the cross-linked structures formed by traditional vulcanization systems are -S-S-bonds, -C-S-bonds and -C-C-bonds, these irreversible cross-linked bonds will cause the vulcanized rubber cross-linked network to be "refractory and insoluble". At present, the main recycling methods for waste rubber are landfilling, incineration, heat energy utilization and making rubber powder. A small amount of rubber is prepared into reclaimed rubber using traditional desulfurization technology without selectivity, but this will inevitably destroy the rubber main chain structure, causing The molecular weight is seriously reduced, resulting in the performance of the reclaimed rubber being unable to meet subsequent processing requirements. At the same time, the production process of reclaimed rubber has shortcomings such as serious secondary pollution, high energy consumption, low efficiency, and long production process.

As the application scope of rubber continues to expand, people's requirements for its performance are gradually increasing. However, without reinforcing agents added to rubber, its strength and modulus are low, which does not meet the performance requirements of the application, seriously affecting the use value of rubber. Among them, carbon black (CB) and silica are the most commonly used reinforcing agents in the production process of rubber products. The reinforcing effects are obvious, but they have high production costs, over-reliance on petrochemical resources and serious environmental pollution caused during the production process. This is a shortcoming that traditional reinforcing agents cannot overcome.

Therefore, in order to fundamentally solve these problems, it is necessary to design a new cross-linking system that is different from sulfur vulcanization and peroxide vulcanization.

Contents of the invention

In order to solve the problems existing in the prior art, the present invention provides an amidoxime functionalized nitrile rubber and its preparation method and application. In the present invention, after the nitrile rubber is functionally modified with an oxime, a "covalent" cross-linked network formed by self-crosslinking, a hydrogen-bonded cross-linked network formed by intermolecular "hydrogen bonds", and a "covalent" cross-linked network formed by coordination interaction are used. "bit bond" cross-linked network to prepare rubber materials with self-cross-linking and self-reinforcement. Without the addition of cross-linking agents and reinforcing agents, this cross-linking system only utilizes the self-cross-linking effect of its own amine oxime bond, hydrogen bonding effect and coordination effect with metal ions. This cross-linking system is green and environmentally friendly, and the vulcanization process is No unpleasant pungent odor will be produced in the rubber. At the same time, the use of "hydrogen bonds" and "coordination bonds" will dissipate a large amount of energy during the fracture and reorganization process to achieve self-reinforcement and toughening of the rubber.

One of the objects of the present invention is to provide an aminooxime functionalized nitrile rubber, the structural formula of the aminooxime functionalized nitrile rubber is:

Among them, x is 1-6000, y is 1-6000, and z is 20-6000; preferably, x is 100-5000, y is 100-5000, and z is 50-5000.

Preferably, the functionalization degree of the amidoxime functionalized nitrile rubber is 2-15%; preferably, the functionalization degree is 5-10%.

The second object of the present invention is to provide a preparation method of amidoxime functionalized nitrile rubber, which method includes:

Dissolve the nitrile rubber in the polar solvent, add the initial reaction hydroxylamine hydrochloride solution and alkali solution, stir the reaction, during the reaction process, add the same amount of hydroxylamine hydrochloride solution and alkali solution as the initial reaction in batches, the reaction is completed , after washing, flocculation and drying, the amidoxime functionalized nitrile rubber is obtained. The purpose of adding hydroxylamine hydrochloride and alkali in batches is to improve the reaction efficiency and improve the degree of amine oximation modification.

The reaction principle is shown in the following reaction equation:

Preferably, the solution concentration after the nitrile rubber is dissolved is 1-30g/100ml, preferably 4-15g/100ml;

The molar ratio of the initial reaction base and hydroxylamine hydrochloride is (0.1-4):1, preferably (1-2):1;

The concentration of alkali solution for the initial reaction is 40-70g/100ml;

The concentration of hydroxylamine hydrochloride solution in the initial reaction is 5-20g/100ml;

The molar ratio of acrylonitrile monomer and initial reacted hydroxylamine hydrochloride in nitrile rubber is 1: (0.4-0.8);

Add 1-4 additional batches of hydroxylamine subhydrochloride solution and alkali solution in the same amount as the initial reaction, and the interval between each batch is 6-8 hours;

The reaction temperature is 40-80°C, preferably 40-60°C; the reaction time is 6-72h, preferably 8-24h; the stirring speed is 100-1000r/min, preferably 150-1000r/min.

Specifically, the following solutions can be adopted:

The methods include:

(1) Dissolution of nitrile rubber: First, cut the nitrile rubber into particles with a diameter of about 1.5cm, dissolve it in a three-necked flask with a polar solvent, and start stirring until a uniform and transparent nitrile rubber solution is formed. The concentration of the nitrile rubber solution is controlled at 1-30g/100ml, preferably 4-15g/100ml;

(2) After complete dissolution, add hydroxylamine hydrochloride solution and alkali solution and mix for 10-15 minutes. After stirring evenly, adjust the water bath temperature to 40-60°C, place a spherical condenser tube, open the condensed water, start timing, and react for 6-72 hours , preferably 8-24h, add hydroxylamine hydrochloride solution and alkali solution every 6-8 hours of reaction (up to 4 times, too much solvent will cause the glue in the system to flocculate out);

(3) End the reaction and flocculate: After the reaction is completed, remove the water bath heating, use a separatory funnel to slowly pour the reaction system into 40°C deionized water, wash it until it is neutral, and wash away unreacted raw materials and impurities. The product is flocculated, 2 times the volume of flocculant is added to precipitate the rubber, and finally the rubber is dried in a 60°C vacuum oven to a constant weight to obtain the amidoxime functionalized nitrile rubber.

Preferably, the acrylonitrile content of the nitrile rubber is 2-60wt%, preferably 10-50wt%;

All nitrile-butadiene rubbers in the art with acrylonitrile content within this range can be used. Such as: solid nitrile rubber, liquid nitrile rubber;

The solid nitrile rubber may be preferably at least one of ordinary nitrile rubber, carboxyl nitrile rubber, and hydrogenated nitrile rubber; more preferably, ordinary nitrile rubber;

The ordinary nitrile rubber is a solid rubber with a main chain structure of butadiene and acrylonitrile and does not contain other functional groups;

The liquid nitrile rubber is preferably at least one of ordinary liquid nitrile rubber, hydroxyl-terminated liquid nitrile rubber, carboxyl-terminated liquid nitrile rubber, amino-terminated liquid nitrile rubber, and sulfur-terminated liquid nitrile rubber;

The ordinary liquid nitrile rubber is liquid nitrile rubber that does not contain other functional groups;

The polar solvent is at least one of tetrahydrofuran, toluene, xylene, cyclohexane, cyclopentane, n-hexane, n-heptane, dichloromethane, dichloroethane, chloroform, isopropanol, and acetonitrile. kind;

The alkali is at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, and anhydrous sodium carbonate;

The solvent of the hydroxylamine hydrochloride solution and the alkali solution is at least one of methanol, ethanol, and butanol;

The flocculant used in the flocculation process is at least one of methanol, ethanol, butanol, acetone, butanone, and water.

The third object of the present invention is to provide a self-crosslinking and self-reinforcing rubber prepared from amidoxime functionalized nitrile rubber. The self-crosslinking and self-reinforcing rubber is kneaded and vulcanized from raw materials including the following components: After making:

Aminoxime functionalized nitrile rubber and metal salts;

Each component is calculated in parts by weight:

Aminoxime functionalized nitrile rubber 100 parts by weight;

Metal salt 0.1-20 parts by weight, preferably 0.5-10 parts by weight.

Preferably, the metal salt is at least one of zinc acetate, zinc chloride, zinc oxide, ferric chloride, nickel chloride, and cobalt chloride.

The fourth object of the present invention is to provide a preparation method of self-crosslinking and self-reinforcing rubber, which method includes:

The self-crosslinking and self-reinforcing rubber is prepared by mixing and vulcanizing the components according to the weight.

Preferably, the vulcanization temperature is 90-300°C, preferably 120-200°C; the vulcanization time is 1min-24h, preferably 10-90min.

Specifically, the following solutions can be adopted:

The present invention can specifically adopt the following technical solutions:

Aminoxime functionalized nitrile rubber and metal salts are mixed to obtain a mixed rubber, which is then vulcanized under a certain temperature and pressure to obtain a self-crosslinked and self-reinforced rubber with multiple cross-linked networks.

In the present invention, nitrile rubber is functionally modified with amine oxime, and amine oxime bonds are introduced into the molecular chain of the rubber. The amine oxime bonds can undergo self-condensation at high temperatures to produce a "covalent" cross-linked network; at the same time, The nitrile rubber modified by the amidoxime functionalization is mixed and vulcanized with the metal salt. The metal ions in the metal salt can coordinate with the ligands on the rubber (i.e. the amidoxime bond) to obtain metal coordination bonds; and the amidoxime functional The "hydrogen bonds" between nitrile rubber molecules can form a hydrogen bond cross-linked network. As a result, the molecular chain of the self-crosslinking and self-reinforcing rubber of the present invention contains a hydrogen bond cross-linking network, a metal coordination bond cross-linking network and a covalent bond cross-linking network. Among them, hydrogen bonds and metal coordination bonds serve as physical cross-linking points and play a "sacrificial" role in the cross-linked network, because hydrogen bonds and metal coordination bonds dissipate a large amount of energy during the process of breakage and reorganization, which can realize rubber Self-reinforcement and self-toughening, thereby significantly improving the physical and mechanical properties of the material. Therefore, the present invention can prepare "self-reinforcing" rubber materials with multiple cross-linked networks without adding external cross-linking agents and reinforcing agents. This cross-linked system is green and environmentally friendly and will not produce unpleasant pungent odors during the vulcanization process.

Compared with the existing technology, the beneficial technical benefits of the present invention are:

(1) In the present invention, alkali is added according to the molar ratio to neutralize hydroxylamine hydrochloride, which can make it easier for the hydroxylamine group to be grafted onto the nitrile rubber molecular chain; at the same time, the creative method of adding hydroxylamine hydrochloride and alkali every 6-8 hours is creative. It can maximize the functional modification degree of amine oxime.

(2) In the present invention, by controlling the concentration of nitrile rubber, the formulation of amidoxime functionalization, reaction stirring speed, reaction temperature, reaction time, type of solvent, etc., the conditions for functionalization of amidoxime are optimized to achieve the best technology. Effect; and the present invention is easier to control the reaction process, and the raw materials used in the reaction are low in price and green and environmentally friendly.

(3) In the present invention, the amine oxime bond can undergo self-condensation at high temperatures to produce a "covalent" cross-linked network. At the same time, hydrogen bonds and metal coordination bonds serve as physical cross-linking points and play a "covalent" cross-linked network. Therefore, it is possible to prepare "self-reinforcing" rubber materials with multiple cross-linked networks without adding external cross-linking agents and reinforcing agents.

Description of drawings

Figure 1 is the infrared spectrum before and after the amidoxime functionalized nitrile rubber of the present invention;

The degree of amine oximation modification is calculated based on the integral of the corresponding peak area of the NMR spectrum (that is, the molar ratio of the amine oxime bond to the monomer). In the figure, 0%, 2%, 5%, 8%, and 10% represent different amines respectively. Nitrile rubber modified by oxime functionalization, the peak at 2237cm ^-1 is the characteristic peak of -CN on the NBR molecular chain, and the peak value continues to decrease with the increase in the degree of modification; after oxime functional modification, nitrile rubber Three new peaks appeared in the FTIR spectrum, namely -OH vibration peak at 3490cm ^-1 , -NH ₂ vibration peak at 3376cm ^-1 and -C=N- vibration peak at 1658cm ^-1 . The intensity of these absorption peaks gradually increases with the increase in the degree of functional modification, indicating that more amine oxime bonds are grafted, which is beneficial to the construction of subsequent cross-linked networks.

Figure 2 is the nuclear magnetic spectrum before and after the amidoxime functionalized nitrile rubber of the present invention;

The degree of amine oximation modification is calculated based on the integral of the corresponding peak area of the NMR spectrum (that is, the molar ratio of the amine oxime bond to the monomer). In the figure, 0%, 2%, 5%, 8%, and 10% represent different amines respectively. For oxime functionalized modified nitrile rubber, the characteristic peaks of H atoms on -NH ₂ and -OH can be observed at 8.88-6.52ppm and 4.56-3.49ppm respectively, and as the degree of modification increases, its The peak intensity gradually increases, indicating that more amine oxime bonds are grafted, which is beneficial to the construction of subsequent cross-linked networks.

Figure 3 is a reaction principle diagram of the self-crosslinking and self-reinforcing rubber of the present invention.

In the figure, amine oxime bonds are introduced into the molecular chain of rubber. The amine oxime bonds can produce a "covalent" cross-linked network at high temperatures; at the same time, the nitrile rubber and metal salts functionalized and modified by amine oxime are mixed and vulcanized. The metal ions in the metal salt (the metal ions selected here are zinc ions) can coordinate with the amine oxime bonds on the rubber to obtain metal coordination bonds; and the "hydrogen bonds" between the molecules of the amine oxime functionalized nitrile rubber can be formed Hydrogen bonded cross-linked network. As a result, the molecular chain of the self-crosslinking and self-reinforcing rubber of the present invention contains a hydrogen bond cross-linking network, a metal coordination bond cross-linking network and a covalent bond cross-linking network.

Detailed ways

The present invention will be described in detail below with reference to specific drawings and examples. It is necessary to point out here that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of the present invention. Those skilled in the art will refer to this SUMMARY OF THE INVENTION Some non-essential improvements and adjustments made to the present invention still fall within the protection scope of the present invention.

The raw materials used in the examples are all commercially available. The specific raw material information is as follows in Table 1:

Table 1

name abbreviation Product Description Ordinary nitrile rubber NBR220S Japan JSR Carboxylic nitrile rubber XNBR Lanxess Chemical of Germany Ordinary liquid nitrile rubber LNBR Lanxess Chemical of Germany Hydroxylamine hydrochloride NH ₂ OH·HCl 99%,TCI Potassium hydroxide KOH Analytical grade, Sigma-Aldrich anhydrous sodium carbonate Na ₂ CO ₃ Analytical grade, Beijing Chemical Factory sodium hydroxide NaOH Analytical grade, Beijing Chemical Factory Tetrahydrofuran THF Analytical grade, Beijing Chemical Factory xylene -- Analytical grade, Beijing Chemical Factory Chloroform CHCl ₃ Analytical grade, Beijing Chemical Factory Anhydrous ethanol -- Analytical grade, Sinopharm Reagents (Beijing) Co., Ltd. Anhydrous methanol -- Analytical grade, Sinopharm Reagents (Beijing) Co., Ltd. zinc acetate Zn(OAc) ₂ Analytically pure, Shanghai McLean Company zinc chloride ZnCl ₂ 99%,TCI ferric chloride FeCl ₃ 99%, Alfa-Aesar

Example 1

(1) Preparation of amidoxime functionalized nitrile rubber: In a 1000ml three-necked flask, add 30g of ordinary nitrile rubber (acrylonitrile content is 42wt%, acrylonitrile molar weight is 0.23) and 250ml THF, and start stirring until it forms Homogeneous and clear solution of nitrile rubber. After complete dissolution, dissolve 7g NH ₂ OH·HCl in 40g anhydrous methanol to form an anhydrous methanol solution of hydroxylamine hydrochloride with a concentration of 13g/100ml; dissolve 6.16g KOH in 10g anhydrous methanol to form a concentration of 50g /100ml of anhydrous methanol solution of potassium hydroxide, (KOH: NH ₂ OH·HCl molar ratio is 1:1); add it to the nitrile rubber solution at room temperature, mix for 15 minutes, wait until evenly stirred, and adjust the water bath temperature to 60 ℃, after the temperature is constant, place the spherical condenser tube, open the condensed water, stir the speed at 300r/min, and react for 18 hours. During the reaction, every 6 hours, add anhydrous methanol solution of hydroxylamine hydrochloride and hydroxide with the same concentration as above. Anhydrous methanol solution of potassium was added three times in total. After the reaction is completed, use a separatory funnel to slowly add the reaction system to 40°C deionized water, wash away unreacted raw materials and impurities, add 2 times the volume of absolute ethanol, flocculate and separate the rubber, and finally put the rubber into 60 Dry in a vacuum oven at ℃ until constant weight to obtain amidoxime functionalized nitrile rubber.

(2) Preparation of self-crosslinking and self-reinforcing rubber: Mix 100 parts by weight of amidoxime functionalized nitrile rubber and 2 parts by weight of zinc acetate on an open mill to obtain a mixed rubber, and then mix it at 160°C and 15MPa pressure Next, vulcanize for 30 minutes to obtain self-crosslinking and self-reinforcing rubber.

Example 2

The difference between Example 2 and Example 1 lies in: reaction temperature, reaction time, stirring speed and type of nitrile rubber. In Example 2, the reaction temperature is 40°C and the reaction time is 72h. During the reaction, the anhydrous methanol solution of hydroxylamine hydrochloride and the anhydrous methanol solution of potassium hydroxide with the same concentration as above are added every 6h, and 4 times, the stirring speed is 100 r/min, and the nitrile rubber is carboxyl nitrile rubber (acrylonitrile content is 33wt%, molar weight is 0.19). Other processes and dosages are the same as in Example 1.

Example 3

The difference between Example 3 and Example 1 lies in: reaction temperature, reaction time, stirring speed and type of nitrile rubber. In Example 3, the reaction temperature is 80°C and the reaction time is 7h. During the reaction, the anhydrous methanol solution of hydroxylamine hydrochloride and the anhydrous methanol solution of potassium hydroxide with the same concentration as above are added every 6h, and 1 times, the stirring speed is 1000r/min, and the nitrile rubber is ordinary liquid nitrile rubber (acrylonitrile content is 47wt%, molar weight is 0.26). Other processes and dosages are the same as in Example 1.

Example 4

The difference between Example 4 and Example 1 lies in the concentration of the rubber solution, the amount of hydroxylamine hydrochloride, the amount of alkali, and the amount of solvent. In Example 4, the addition amount of ordinary nitrile rubber is 10g, 2.33g of NH ₂ OH·HCl is dissolved in 13.33g of anhydrous methanol, and 2.05g of KOH is dissolved in 3.33g of anhydrous methanol. Other processes are as follows: The dosage is the same as in Example 1.

Example 5

The difference between Example 5 and Example 1 lies in: the concentration of the rubber solution, the amount of hydroxylamine hydrochloride, the amount of alkali, and the amount of solvent. In Example 5, the addition amount of ordinary nitrile rubber is 60g, 14g NH ₂ OH·HCl is dissolved in 80g anhydrous methanol, 12.32g KOH is dissolved in 20g anhydrous methanol, and other processes and dosages are the same as those in Example 1 same.

Example 6

The difference between Example 6 and Example 1 lies in the amount of base used, the amount of solvent used, and the type of polar solvent. In Example 6, the molar ratio of alkali to hydroxylamine hydrochloride is 0.1:1, 0.616g KOH is dissolved in 1g anhydrous methanol, and the polar solvent for dissolving nitrile rubber is xylene. Other processes and dosages are the same as in Example 1.

Example 7

The difference between Example 7 and Example 1 lies in the amount of base used, the amount of solvent used, and the type of polar solvent. In Example 7, the molar ratio of alkali to hydroxylamine hydrochloride is 4:1, 24.64g of KOH is dissolved in 40g of anhydrous methanol, and the polar solvent for dissolving nitrile rubber is chloroform. Other processes and dosages are the same as in Example 1.

Example 8

The difference between Example 8 and Example 1 lies in the type of alkali and the type of flocculant. In Example 8, the base is anhydrous sodium carbonate, and the flocculant is methanol. Other processes and dosages are the same as in Example 1.

Example 9

The difference between Example 9 and Example 1 lies in the type of alkali and the type of flocculant. In Example 9, the alkali is sodium hydroxide and the flocculant is methanol. Other processes and dosages are the same as in Example 1.

Example 10

The difference between Example 10 and Example 1 lies in the type and amount of metal salt, vulcanization temperature and vulcanization time. In Example 10, the metal salt is FeCl ₃ , the dosage is 0.5 parts by weight, the vulcanization temperature is 200°C, and the vulcanization time is 1 minute. Other processes and dosages are the same as in Example 1.

Example 11

The difference between Example 11 and Example 1 lies in the type and amount of cross-linking agent, vulcanization temperature and vulcanization time. In Example 11, the metal salt is ZnCl ₂ , the dosage is 15 parts by weight, the vulcanization temperature is 120°C, and the vulcanization time is 24 hours. Other processes and dosages are the same as in Example 1.

Comparative example 1

The difference between Comparative Example 1 and Example 1 lies in the amount of alkali used. In Comparative Example 1, no base was added. Other processes and dosages are the same as in Example 1.

Comparative example 2

The difference between Comparative Example 2 and Example 1 lies in the addition of raw materials during the reaction process. In Comparative Example 2, at the beginning of the reaction, 7g NH2OH·HCl was dissolved in 40g anhydrous methanol, and 6.16g KOH was dissolved in 10g anhydrous methanol and added to the system. No alkali and hydroxylamine hydrochloride were added during the reaction. Other processes and dosages are the same as in Example 1.

Comparative example 3

The difference between Comparative Example 3 and Example 1 lies in the vulcanization temperature. In Comparative Example 3, the vulcanization temperature was 80°C. Other processes and dosages are the same as in Example 1.

Comparative example 4

The difference between Comparative Example 4 and Example 1 lies in the amount of metal salt used. In Comparative Example 4, no metal salt was added to the open mill. Other processes and dosages are the same as in Example 1.

Conduct infrared and nuclear magnetic tests on the amidoxime functionalized nitrile rubber samples prepared in the Examples and Comparative Examples; conduct tensile and vulcanization characteristic tests on the self-crosslinking and self-reinforcing rubber samples prepared in the Examples and Comparative Examples. The test method is as follows:

1. Infrared test: Use the Tensor 27 infrared spectrometer from Bruker Company of Germany to test, and the wave number is set to 400 to 4000cm ^-1 . First, the sample to be tested was dissolved in THF with a concentration of 2.5wt%. After the sample was completely dissolved, the sample solution was dropped onto the pre-pressed KBr flakes and dried in an infrared oven before testing.

2. NMR test: Use Bruker's AV600 600MHz NMR for 1H-NMR characterization. Weigh about 12-15mg of sample and dissolve it in CDCl3 for testing.

3. Tensile test: conducted using the CMT4104 universal material experimental testing machine of Shenzhen Sansi (SANS) Company. The preparation of specimens, test methods and test result processing in the rubber standard tensile test are carried out in accordance with the requirements of the GB/T 528-2009 test standard.

4. Vulcanization characteristics test: The MR·C3 rotorless vulcanizer of Beijing Ruida Yuchen Instrument Co., Ltd. was used to characterize the vulcanization characteristics of the rubber.

The specific test results are as follows in Table 2:

Table 2

Among them, the degree of amine oximation modification is calculated based on the integral of the corresponding peak area of the nuclear magnetic spectrum (that is, the molar ratio of the amine oxime bond to the monomer).

It can be seen from the test results of Examples 1 and 3 that as the reaction time prolongs, the degree of functionalization of amidoxime increases, and 10% of functionalization of amidoxime can be reached after 18 hours. It can be seen from the test results of Example 1 and Comparative Example 1 that if alkali is not added to the system to neutralize hydrochloric acid, it will be difficult for the hydroxylamine group to be grafted onto the rubber molecular chain, resulting in a low degree of functionalization. It can be seen from the test results of Example 1 and Comparative Example 2 that during the reaction process, if hydroxylamine hydrochloride and alkali solution are not added, the number of hydroxylamine groups grafted to the molecular chain will be very small, resulting in a low degree of functionalization. lower. It can be seen from the test results of Example 1 and Comparative Example 3 that the vulcanization temperature is relatively low at 80°C, and the amine oxime bond cannot produce a "covalent" cross-linked network at this temperature, resulting in a decrease in the tensile strength of the system. It can be seen from the test results of Example 1, Example 10, Example 11 and Comparative Example 4 that as the amount of metal salt increases, the tensile properties of the vulcanized sample are significantly improved; in Comparative Example 4, it is not on the open mill. After adding metal salt for kneading, the tensile strength of the sample after vulcanization was reduced by 8 MPa compared with Example 1, and the self-reinforcing effect of the rubber could not be achieved.

Claims (10)

1. An amine oxime functionalized nitrile rubber characterized in that: the structural formula of the amine oxime functionalized nitrile rubber is as follows:

wherein x is 1-6000, y is 1-6000, and z is 20-6000; preferably, x is 100 to 5000, y is 100 to 5000, and z is 50 to 5000.

2. The amine oxime-functionalized nitrile rubber according to claim 1, characterized in that: the amine oxime functionalized nitrile rubber has a functionalization degree of 2-15%; preferably, the degree of functionalization is from 5 to 10%.

3. A process for the preparation of an amine oxime-functionalized nitrile rubber according to claim 1 or 2, characterized in that it comprises:

dissolving nitrile rubber in a polar solvent, adding an initial reaction hydroxylamine hydrochloride solution and an alkali solution, stirring for reaction, adding the same amount of the initial reaction hydroxylamine hydrochloride solution and the same amount of the initial reaction alkali solution in batches in the reaction process, and washing, flocculating and drying to obtain the amine oxime functionalized nitrile rubber after the reaction is finished.

4. A process for the preparation of an amine oxime functionalized nitrile rubber according to claim 3, characterized in that:

the concentration of the solution obtained after the nitrile rubber is dissolved is 1-30g/100ml, preferably 4-15g/100ml;

the molar ratio of the base to hydroxylamine hydrochloride initially reacted is (0.1-4): 1, preferably (1-2): 1, a step of;

the concentration of the alkali solution for initial reaction is 40-70g/100ml;

the concentration of the hydroxylamine hydrochloride solution in the initial reaction is 5-20g/100ml;

the molar ratio of acrylonitrile monomer to initially reacted hydroxylamine hydrochloride in the nitrile rubber was 1: (0.4-0.8);

adding 1-4 batches of hydroxylamine hydrochloride solution and alkali solution which are equal to the initial reaction, wherein the interval time of each batch is 6-8 hours;

the reaction temperature is 40-80 ℃, preferably 40-60 ℃; the reaction time is 6-72h, preferably 8-24h; the stirring speed is 100-1000r/min, preferably 150-1000r/min.

5. The process for the preparation of an amine oxime functionalized nitrile rubber according to claim 4, characterized in that:

the acrylonitrile-butadiene rubber has an acrylonitrile content of 2 to 60wt%, preferably 10 to 50wt%;

the polar solvent is at least one of tetrahydrofuran, toluene, xylene, cyclohexane, cyclopentane, n-hexane, n-heptane, dichloromethane, dichloroethane, chloroform, isopropanol and acetonitrile;

the alkali is at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide and anhydrous sodium carbonate;

the solvent of the hydroxylamine hydrochloride solution and the alkali solution is at least one of methanol, ethanol and butanol.

6. The process for the preparation of an amine oxime functionalized nitrile rubber according to claim 4, characterized in that: the nitrile rubber is at least one of common nitrile rubber, carboxyl nitrile rubber, hydrogenated nitrile rubber, common liquid nitrile rubber, hydroxyl-terminated liquid nitrile rubber, carboxyl-terminated liquid nitrile rubber, amino-terminated liquid nitrile rubber and sulfur-terminated liquid nitrile rubber.

7. Self-crosslinking and self-reinforcing rubber prepared from the amine oxime-functionalized nitrile rubber according to claim 1 or 2, characterized in that it is prepared from the following raw materials by mixing and vulcanizing:

amine oxime functionalized nitrile rubber and metal salts;

the components are calculated according to parts by weight:

100 parts by weight of an amine oxime functionalized nitrile rubber;

the metal salt is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight.

8. The self-crosslinking and self-reinforcing rubber of claim 7, wherein: the metal salt is at least one of zinc acetate, zinc chloride, zinc oxide, ferric chloride, nickel chloride and cobalt chloride.

9. A process for the preparation of self-crosslinking and self-reinforcing rubbers according to claim 7 or 8, characterized in that the process comprises:

the self-crosslinking and self-reinforcing rubber is prepared by mixing and vulcanizing the components according to the weight.

10. The method for producing a self-crosslinking and self-reinforcing rubber according to claim 9, wherein: the vulcanization temperature is 90-300 ℃, preferably 120-200 ℃; the vulcanization time is 1min-24h, preferably 10-90min.