Grape seed procyanidine / carboxy nitrile rubber and preparation method thereof

Abstract

The invention discloses grape seed procyanidine / carboxy nitrile rubber and a preparation method thereof, and belongs to the technical field of photothermal conversion elastomers. The raw materials comprise rubber, an anti-aging agent, a cross-linking agent and grape seed procyanidine; the rubber is selected from any one of carboxy nitrile rubber, carboxy styrene-butadiene rubber, nitrile rubber and epoxidized natural rubber; the cross-linking agent is selected from any one of zinc oxide, soluble zinc salt, soluble iron salt and soluble copper salt. The preparation method is applied to the aspect of the photothermal conversion elastomer, solves the problems of environmental pollution and complex preparation process of the existing preparation method of the photothermal conversion elastomer, and has the characteristics of high strength, aging resistance and repeatable processing performance.

Description

Technical Field

[0001] The invention belongs to the technical field of photothermal conversion elastomers, and in particular relates to grape seed proanthocyanidin / carboxyl nitrile rubber and a preparation method thereof. Background Art

[0002] Converting solar energy into heat, electricity, and kinetic energy is one of the most important aspects of solar energy collection, because it is both green and renewable. Therefore, the preparation of photothermal conversion elastomers has become the focus of current research in recent years. The current strategy for preparing photothermal conversion elastomers is mainly to introduce some photothermal conversion materials into elastomers, such as carbon nanotubes, graphene, MXene, and nanometals. However, the preparation of traditional photothermal fillers usually involves toxic solvents, complex synthesis processes, and the strength of the elastomer itself is difficult to meet the actual use requirements of photothermal elastomers.

[0003] At present, people have paid more and more attention to the relationship between greenhouse gas emissions and global warming, which has greatly increased people's research and development of new high-performance photothermal elastomer materials with sustainable development and environmental protection. People have made many contributions to the manufacture of recyclable green photothermal elastomer materials, such as introducing supramolecular interactions or non-covalent interactions, such as hydrogen bonds, ionic bonds, and metal ligand coordination, or reversible covalent bonds such as ester bonds, borate bonds, Diels-Alder bonds, and imine bonds, into thermosetting polymer networks to achieve recyclability. However, for commercial commodity rubber, in order to obtain photothermal conversion elastomers through chemical modification, expensive chemical reagents and complex synthesis procedures are required, which will greatly increase costs on the one hand and cause inevitable damage to the environment on the other hand. In addition, in order to obtain high-performance photothermal elastomers with practical use value, it is not enough to rely solely on modifying rubber. Some fillers need to be added to meet its actual use requirements, such as graphene, carbon nanotubes, carbon black, white carbon black, etc. However, these fillers are all dependent on fossil resources, and the mining of these fossil resources will inevitably cause great harm to the environment.

[0004] In summary, the existing preparation methods of photothermal conversion elastomers have the following problems: First, the preparation of traditional photothermal fillers involves disadvantages such as toxic solvents and complex synthesis processes; second, in order to obtain reproducible photothermal conversion elastomers, a large amount of solvents are required to modify the rubber molecular chains, which inevitably harms the environment; third, the photothermal conversion elastomer needs to be reinforced to meet its actual use requirements, and the traditional mining of fossil resources such as carbon black will cause damage to the environment. Summary of the invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is that the existing method for preparing photothermal conversion elastomers has the problems of environmental pollution and complex preparation process. A grape seed proanthocyanidin / carboxyl nitrile rubber with high strength, aging resistance and repeatable processing performance and a preparation method thereof are proposed.

[0006] In order to solve the technical problem, the technical solution adopted by the present invention is:

[0007] On one hand, the present invention provides a method for preparing grape seed proanthocyanidins / carboxylated nitrile rubber. The raw materials include: rubber, an antioxidant, a crosslinking agent, and grape seed proanthocyanidins; the rubber is selected from any one of carboxylated nitrile rubber, carboxylated styrene-butadiene rubber, nitrile rubber, and epoxidized natural rubber; and the crosslinking agent is selected from any one of zinc oxide, a soluble zinc salt, a soluble iron salt, and a soluble copper salt.

[0008] Preferably, based on parts by mass, the amount of the rubber is selected from any value between 80 and 120 parts, the amount of the antioxidant is selected from any value between 1 and 3 parts, the amount of the cross-linking agent is selected from any value between 0.5 and 5 parts, and the amount of the grape seed proanthocyanidins is selected from any value between 15 and 60 parts.

[0009] Preferably, the raw materials consist of 100 parts of carboxylated nitrile rubber, 1.5 parts of antioxidant 4010NA, 1 part of zinc oxide, and 15-60 parts of grape seed proanthocyanidins.

[0010] Preferably, the preparation method is a mechanical blending method.

[0011] Preferably, the mechanical blending method comprises: mixing rubber, an antioxidant and a cross-linking agent in an internal mixer, then adding dried grape seed proanthocyanidins and continuing to mix and then draining the rubber, leaving the prepared blend at room temperature, and then vulcanizing to obtain the grape seed proanthocyanidins / carboxyl nitrile rubber.

[0012] Preferably, the dried grape seed proanthocyanidins are obtained by the following method: drying the grape seed proanthocyanidins at 40-70° C. for 6-48 hours.

[0013] Preferably, the rubber, antioxidant and cross-linking agent are mixed in an internal mixer at 150-180° C. and 50-80 r / min for 2-10 min, and then the dried grape seed proanthocyanidins are added and mixed for 5-15 min before the rubber is discharged.

[0014] Preferably, the prepared blend is left at room temperature for 24 hours and then vulcanized at 150-180° C. for 10-30 minutes to obtain the grape seed proanthocyanidins / carboxyl nitrile rubber.

[0015] Preferably, the mechanical blending method comprises: drying grape seed proanthocyanidins at 40-70°C for 12 hours; firstly mixing carboxylated nitrile rubber, antioxidant 4010NA and zinc oxide in an internal mixer at 180°C and 60r / min for 2 minutes, then adding grape seed proanthocyanidins and continuing to mix for 5 minutes before debinding, leaving the prepared blend at room temperature for 24 hours, and then vulcanizing at 160°C for 15 minutes.

[0016] Another aspect of the present invention provides a grape seed proanthocyanidin / carboxyl nitrile rubber.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention provides a method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber.

[0019] (1) Using biomass fillers to modify carboxylated nitrile rubber can greatly reduce the exploitation of fossil resources and protect the environment;

[0020] (2) Using grape seed proanthocyanidins as fillers, under the synergistic effect of zinc oxide, can greatly improve the compatibility and interaction between carboxylated nitrile rubber and grape seed proanthocyanidins, improve the dispersibility of grape seed proanthocyanidins in carboxylated nitrile rubber, and thus give carboxylated nitrile rubber better mechanical strength;

[0021] (3) For the blend, there are a large number of intermolecular hydrogen bonds and metal coordination bonds in its structure. These non-covalent bonds can give the blend good reproducibility and can greatly reduce costs;

[0022] (4) Grape seed proanthocyanidins contain a large amount of phenolic hydroxyl groups, which can improve the aging resistance of carboxylated nitrile rubber and reduce costs;

[0023] (5) The structure of the grape seed proanthocyanidins selected in the present invention contains a large number of aromatic rings and conjugated functional groups, which form strong conjugation and π-π molecular interactions in the grape seed proanthocyanidins, which endows the grape seed proanthocyanidins with the potential for photothermal conversion. Blending it with carboxylated nitrile rubber can give it better photothermal conversion performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The temperature rise curve of the materials provided in Example 2 and Comparative Example 1 of the present invention under 808nm infrared irradiation;

[0025] Figure 2 The mechanical property retention rate of the materials provided in Example 2 and Comparative Example 1 of the present invention after hot air aging for 24 hours;

[0026] Figure 3This is a schematic diagram of the microscopic morphology of the material provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0027] The technical scheme in the specific embodiment of the present invention is described in detail and completely below. Obviously, the described embodiment is only a part of the specific implementation of the overall technical scheme of the present invention, rather than all implementations. Based on the overall concept of the present invention, all other embodiments obtained by ordinary technicians in this field fall within the scope of protection of the present invention.

[0028] On one hand, the present invention provides a method for preparing grape seed proanthocyanidin / carboxylated nitrile rubber, wherein the raw materials include: rubber, an antioxidant, a crosslinking agent, and grape seed proanthocyanidin; the rubber is selected from any one of carboxylated nitrile rubber, carboxylated styrene-butadiene rubber, nitrile rubber, and epoxidized natural rubber; the crosslinking agent is selected from any one of zinc oxide, soluble zinc salt, soluble iron salt, and soluble copper salt. The film made from the grape seed proanthocyanidin / carboxylated nitrile rubber as a raw material has the characteristics of high strength, aging resistance, repeatable processing, and good light-to-heat conversion performance.

[0029] The above technical scheme limits the use of grape seed proanthocyanidins as raw materials, wherein anthocyanidins and proanthocyanidins are two natural products widely present in the plant kingdom, both of which have the effects of anti-oxidation and elimination of free radicals, but the effect of proanthocyanidins is stronger, because proanthocyanidins belong to polyphenolic compounds, while anthocyanidins belong to flavonoid compounds. Proanthocyanidins contain a large number of phenolic hydroxyl groups, which will produce intermolecular hydrogen bond interactions with the carboxyl groups in carboxylated nitrile rubber, and the added zinc oxide will also form metal coordination bonds with proanthocyanidins / carboxylated nitrile rubber, further enhancing the interaction between rubber and proanthocyanidins, and improving the strength of rubber. In addition, proanthocyanidins contain a large number of conjugated structures, which can give rubber better light-heat conversion performance. Further, proanthocyanidins are widely present in the plant kingdom, mainly from the skin, shell, seeds and other parts of plants. Common plants rich in proanthocyanidins include grape seeds, pine bark, etc. This technical solution limits the use of grape seed proanthocyanidins because grape seeds contain high concentrations of polyphenols and have the highest content of proanthocyanidins and a rich variety.

[0030] It is understandable that zinc oxide is used because the zinc ions generated by zinc oxide can generate metal coordination bonds with carboxylated nitrile rubber and grape seed proanthocyanidins, which can improve the compatibility and dispersibility of grape seed proanthocyanidins in carboxylated nitrile rubber. At the same time, soluble zinc salts, iron salts, and copper salts can all generate metal coordination bonds between carboxylated nitrile rubber and proanthocyanidins, so their use effects can be satisfied. Carboxylated nitrile rubber, carboxylated styrene butadiene rubber, nitrile rubber, and epoxidized natural rubber all have groups that can generate metal coordination bonds with zinc ions, and can all achieve the same technical effects as carboxylated nitrile rubber.

[0031] The above preparation method: (1) using biomass filler to modify carboxylated nitrile rubber can greatly reduce the exploitation of fossil resources and protect the environment; (2) using grape seed proanthocyanidins as fillers, under the synergistic effect of zinc oxide, can greatly improve the compatibility and interaction between carboxylated nitrile rubber and grape seed proanthocyanidins, improve the dispersibility of grape seed proanthocyanidins in carboxylated nitrile rubber, and then give carboxylated nitrile rubber better mechanical strength; (3) for the blend, there are a large number of intermolecular hydrogen bonds and metal coordination bonds in its structure, which The non-covalent bond can give the blend good reprocessability and can greatly reduce the cost; (4) Grape seed proanthocyanidins contain a large number of phenolic hydroxyl groups, which can improve the aging resistance of carboxylated nitrile rubber and reduce the cost; (5) The grape seed proanthocyanidins selected in the present invention contain a large number of aromatic rings and conjugated functional groups inside the structure, so that strong conjugation and π-π molecular interactions are formed in the grape seed proanthocyanidins, which gives the grape seed proanthocyanidins the potential for photothermal conversion. Blending it with carboxylated nitrile rubber can give it good photothermal conversion performance.

[0032] In a preferred embodiment, the amount of the rubber is selected from any value of 80-120 parts by mass, the amount of the antioxidant is selected from any value of 1-3 parts, the amount of the cross-linking agent is selected from any value of 0.5-5 parts, and the amount of the grape seed proanthocyanidin is selected from any value of 15-60 parts. The technical solution specifically defines the amount of each component. It can be understood that the amount of the rubber can also be 90 parts, 100 parts, 110 parts and any value within the range, the amount of the antioxidant can also be 1.5 parts, 2 parts, 2.5 parts and any value within the range, the amount of the cross-linking agent can also be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts and any value within the range, and the amount of the grape seed proanthocyanidin can also be 20 parts, 30 parts, 40 parts, 50 parts and any value within the range.

[0033] In a preferred embodiment, the raw materials are composed of 100 parts of carboxylated nitrile rubber, 1.5 parts of antioxidant 4010NA, 1 part of zinc oxide, and 15-60 parts of grape seed proanthocyanidins. Among the above components, zinc oxide, as a cross-linking agent, can generate metal coordination bonds with grape seed proanthocyanidins and carboxylated nitrile rubber to form a cross-linked network structure, 4010NA is an antioxidant, and grape seed proanthocyanidins can be used as a reinforcing agent, antioxidant, and photothermal conversion agent. Specifically, zinc oxide is used as a "bridging agent", which can form metal coordination bonds between carboxy nitrile rubber and grape seed proanthocyanidins, respectively, to improve the interaction and compatibility between the two, so that the grape seed proanthocyanidins can be more evenly dispersed in the carboxy nitrile rubber matrix; in the carboxy nitrile rubber / grape seed proanthocyanidins composite material, there is also an intermolecular hydrogen bond interaction between the rubber and the grape seed proanthocyanidins, which makes the composite material have good mechanical strength, and the metal coordination bond formed between zinc oxide and grape seed proanthocyanidins can reduce the electronic transition energy band gap of grape seed proanthocyanidins during photothermal conversion, thereby enhancing the photothermal conversion performance of grape seed proanthocyanidins; the good interface interaction between the rubber matrix and the grape seed proanthocyanidins can effectively promote heat transfer, thereby improving the photothermal conversion performance of the composite material.

[0034] In a preferred embodiment, the preparation method is a mechanical blending method. Specifically, the mechanical blending method includes: mixing rubber, antioxidant and cross-linking agent in an internal mixer, then adding dried grape seed proanthocyanidin and continuing to mix and drain the glue, leaving the prepared blend at room temperature, and then vulcanizing to obtain the grape seed proanthocyanidin / carboxyl nitrile rubber. This technical solution stipulates that the rubber, antioxidant and cross-linking agent are first mixed in an internal mixer and then the dried grape seed proanthocyanidin is added and continued to mix, instead of adding the dried grape seed proanthocyanidin together with the rubber, antioxidant and cross-linking agent for mixing, which ensures that the grape seed proanthocyanidin plays a better role.

[0035] In a preferred embodiment, the dried grape seed proanthocyanidins are obtained by the following method: drying the grape seed proanthocyanidins at 40-70° C. for 6-48 hours. The technical solution specifically limits the temperature and time for drying the grape seed proanthocyanidins because grape seed proanthocyanidins contain a large number of polar groups and are easy to absorb water, and it is necessary to ensure that the water is effectively removed.

[0036] In a preferred embodiment, the rubber, antioxidant and cross-linking agent are mixed in an internal mixer at 150-180°C and 50-80r / min for 2-10 minutes, and then the dried grape seed proanthocyanidins are added and mixed for 5-15 minutes before rubber removal. The technical solution specifically limits the mixing temperature and time because, under certain temperature conditions, the mixing time can be controlled to ensure that the components can be fully mixed evenly.

[0037] In a preferred embodiment, the prepared blend is left at room temperature for 24 hours, and then vulcanized at 150-180°C for 10-30 minutes to obtain the grape seed proanthocyanidins / carboxylated nitrile rubber. The technical solution specifically defines the vulcanization temperature and time, because it ensures that the zinc ions are uniformly dispersed in the carboxylated nitrile rubber / grape seed proanthocyanidins composite material and forms a metal coordination bond network structure with the zinc ions as the cross-linking center.

[0038] In a preferred embodiment, the mechanical blending method includes: drying grape seed proanthocyanidins at 40-70°C for 12 hours; first mixing carboxylated nitrile rubber, antioxidant 4010NA and zinc oxide in an internal mixer at 180°C and 60r / min for 2 minutes, then adding grape seed proanthocyanidins and continuing to mix for 5 minutes before debinding, leaving the prepared blend at room temperature for 24 hours, and then vulcanizing at 160°C for 15 minutes.

[0039] Another aspect of the present invention provides a grape seed proanthocyanidin / carboxylated nitrile rubber. A film made from the grape seed proanthocyanidin / carboxylated nitrile rubber as a raw material has good high strength, high elongation at break, aging resistance, repeatability and excellent light-to-heat conversion performance.

[0040] The above technical solution effectively solves the problem of environmental pollution through simple mechanical blending without using toxic solvents that pollute the environment. The prepared photothermal conversion elastomer can be repeatedly processed and reused and is resistant to aging, which can greatly reduce costs. The use of grape seed proanthocyanidins to study the preparation of materials with photothermal conversion function in rubber has good guiding significance for the future preparation of photothermal conversion materials.

[0041] In order to more clearly and in detail introduce the grape seed proanthocyanidins / carboxyl nitrile rubber and the preparation method thereof provided by the embodiments of the present invention, they will be described below in conjunction with specific embodiments.

[0042] Example 1

[0043] (1) Formula composition: 100 parts of carboxylated nitrile rubber, 1.5 parts of antioxidant 4010NA, 1 part of zinc oxide, and 15 parts of grape seed proanthocyanidins;

[0044] (2) Preparation steps:

[0045] Before use, use an oven (40-70°C) to dry the grape seed proanthocyanidins for 12 hours;

[0046] First, carboxyl nitrile rubber, antioxidant 4010NA and zinc oxide were mixed in an internal mixer (180°C, 60r / min) for 2 minutes, and then grape seed proanthocyanidins were added and mixed for 5 minutes before the rubber was discharged;

[0047] The prepared blend was left at room temperature for 24 h and then vulcanized at 160 °C for 15 min.

[0048] Example 2

[0049] (1) Formula composition: 100 parts of carboxylated nitrile rubber, 1.5 parts of antioxidant 4010NA, 1 part of zinc oxide, and 30 parts of grape seed proanthocyanidins;

[0050] (2) Preparation steps:

[0051] Before use, use an oven (40-70°C) to dry the grape seed proanthocyanidins for 12 hours;

[0052] First, carboxyl nitrile rubber, antioxidant 4010NA and zinc oxide were mixed in an internal mixer (180°C, 60r / min) for 2 minutes, and then grape seed proanthocyanidins were added and mixed for 5 minutes before the rubber was discharged;

[0053] The prepared blend was placed at room temperature for 24 h and then vulcanized at 160 °C for 15 min. The microstructure of the obtained material is as follows: Figure 3 Show.

[0054] Example 3

[0055] (1) Formula composition: 100 parts of carboxylated nitrile rubber, 1.5 parts of antioxidant 4010NA, 1 part of zinc oxide, and 45 parts of grape seed proanthocyanidins;

[0056] (2) Preparation steps:

[0057] Before use, use an oven (40-70°C) to dry the grape seed proanthocyanidins for 12 hours;

[0058] First, carboxyl nitrile rubber, antioxidant 4010NA and zinc oxide were mixed in an internal mixer (180°C, 60r / min) for 2 minutes, and then grape seed proanthocyanidins were added and mixed for 5 minutes before the rubber was discharged;

[0059] The prepared blend was left at room temperature for 24 h and then vulcanized at 160 °C for 15 min.

[0060] Comparative Example 1

[0061] (1) Formula composition: 100 parts of carboxylated nitrile rubber, 1.5 parts of antioxidant 4010NA, and 1 part of zinc oxide;

[0062] (2) Preparation steps: carboxyl nitrile rubber, antioxidant 4010NA and zinc oxide were mixed in an internal mixer (180°C, 60 r / min) for 2 min; the prepared blend was left at room temperature for 24 h and then vulcanized at 160°C for 15 min.

[0063] Performance Testing

[0064] The performance of the materials prepared in the above Examples 1-3 and Comparative Example 1 was tested, and the test results are shown in Table 1.

[0065] Table 1 Performance test results of materials prepared in Examples 1-3 and Comparative Example 1

[0066]

[0067] The material obtained in Example 2 was subjected to repeated processing performance tests, and the test results are shown in Table 2.

[0068] Table 2 Repeatability test results of materials obtained in Example 2

[0069] Original sample Samples were processed repeatedly Samples were processed twice Tensile strength, MPa 10.3 8.8 8.3 Elongation at break, % 1004 934 912

[0070] Combination Figure 1 , 2 It can be found that the addition of grape seed proanthocyanidins can significantly improve the mechanical properties of the carboxylated nitrile rubber / grape seed proanthocyanidins composite material, and the composite material can be repeatedly processed, and its mechanical properties can be maintained well before and after two repeated processing.

Claims

1. A method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber, characterized in that: The raw materials include: rubber, antioxidant, crosslinking agent, and grape seed proanthocyanidin; the rubber is selected from any one of carboxylated nitrile rubber, carboxylated styrene-butadiene rubber, nitrile rubber and epoxidized natural rubber; the crosslinking agent is selected from any one of zinc oxide, soluble zinc salt, soluble iron salt and soluble copper salt.

2. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 1, characterized in that: In parts by mass, the amount of the rubber is selected from any value between 80 and 120 parts, the amount of the antioxidant is selected from any value between 1 and 3 parts, the amount of the cross-linking agent is selected from any value between 0.5 and 5 parts, and the amount of the grape seed proanthocyanidins is selected from any value between 15 and 60 parts.

3. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 1, characterized in that: The raw materials consist of 100 parts of carboxyl nitrile rubber, 1.5 parts of antioxidant 4010NA, 1 part of zinc oxide and 15-60 parts of grape seed proanthocyanidins.

4. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 1, characterized in that: The preparation method is mechanical blending.

5. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 4, characterized in that: The mechanical blending method comprises: mixing rubber, an antioxidant and a cross-linking agent in an internal mixer, then adding dried grape seed proanthocyanidins and continuing to mix and discharge the rubber, leaving the prepared blend at room temperature, and then vulcanizing to obtain the grape seed proanthocyanidins / carboxyl nitrile rubber.

6. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 5, characterized in that: The dried grape seed proanthocyanidins are obtained by the following method: drying the grape seed proanthocyanidins at 40-70° C. for 6-48 hours.

7. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 5, characterized in that: Rubber, antioxidant and cross-linking agent are mixed in an internal mixer at 150-180°C and 50-80r / min for 2-10min, and then dried grape seed proanthocyanidins are added and mixed for 5-15min and then the rubber is discharged.

8. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 5, characterized in that: The prepared blend was allowed to stand at room temperature for 24 hours, and then vulcanized at 150-180° C. for 10-30 minutes to obtain the grape seed proanthocyanidins / carboxyl nitrile rubber.

9. The method for preparing grape seed proanthocyanidins / carboxyl nitrile rubber according to claim 5, characterized in that: The mechanical blending method comprises: drying grape seed proanthocyanidins at 40-70° C. for 12 hours; firstly mixing carboxylated nitrile rubber, antioxidant 4010NA and zinc oxide in an internal mixer at 180° C. and 60 r / min for 2 minutes, then adding grape seed proanthocyanidins and continuing to mix for 5 minutes, and then draining the mixture, leaving the prepared blend at room temperature for 24 hours, and then vulcanizing at 160° C. for 15 minutes.

10. The grape seed proanthocyanidins / carboxyl nitrile rubber according to any one of claims 1 to 9.

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