Preparation method and application of polydithiocarbamate material

Abstract

The invention discloses a preparation method and application of a polydithiocarbamate material. The preparation method comprises the following steps: adding a bifunctional amine compound, alkali and carbon disulfide into an organic solvent, and stirring for reaction; adding a bifunctional bromine compound into the reacted system, stirring for reaction, diluting, precipitating and drying to obtain polydithiocarbamate; and carrying out hot press molding on the polydithiocarbamate to obtain the polydithiocarbamate material. The polydithiocarbamate material prepared by the preparation method disclosed by the invention has a tensile induced enhancement property and excellent dynamic property, and also has excellent repair performance, repeated processing performance, shape memory function and plasticizing function. Through the synergistic effect of a dithiocarbamate group, a crystal region structure and a hydrogen bond network, the polydithiocarbamate material has the advantages of a thermosetting material and a thermoplastic material, and the temporary shape and the permanent shape of the polydithiocarbamate material can be remodeled and fixed.

Description

Technical Field

[0001] The present invention belongs to the field of high mechanical performance engineering materials and intelligent deformation materials, and particularly relates to a preparation method and application of a polydithiocarbamate material. Background Art

[0002] As a commonly used and mature polymer material, polyurethane is often prepared into rubber, plastic, and fiber materials and widely used in social fields such as chemical engineering, construction engineering, and aerospace. However, most polyurethane materials have a major defect that their dynamic performance and recycling performance are poor, which easily causes problems such as resource waste and environmental pollution. The dithiocarbamate group is based on the carbamate group, and all oxygen atoms are replaced by sulfur atoms (sulfur atoms have a large atomic radius and a low bond energy of the carbon-sulfur double bond), resulting in a great improvement in the dynamic properties of polydithiocarbamate compared with polyurethane, making it have excellent self-healing performance, reprocessing performance, shape memory function, and shape reshaping characteristics, overcoming the disadvantages of traditional polyurethane and polyurea materials such as poor dynamic properties, difficult recycling, and low continuous utilization rate. As is well known, thermosetting polymers and thermoplastic polymers are two very common materials. Thermosetting materials have good weather resistance and heat resistance, but they can often only be permanently formed and used once; thermoplastic materials have good processing performance and secondary forming ability, but their heat resistance is poor. How to combine the advantages of thermosetting materials and thermoplastic materials is a major problem. Therefore, it is extremely important to study and prepare a high-performance material that maximally combines the advantages of thermosetting materials and thermoplastic materials and can maintain high performance after self-healing and repeated processing under mild conditions. Preparing high-performance materials with excellent dynamic properties and deformation reshaping performance is also of great significance to the field of polymer materials. Summary of the Invention

[0003] In order to overcome the above-mentioned disadvantages and deficiencies of the prior art, the primary object of the present invention is to provide a preparation method of a high-performance polydithiocarbamate material.

[0004] Another object of the present invention is to provide a high-performance polydithiocarbamate material prepared by the above preparation method.

[0005] Another object of the present invention is to provide the application of the above high-performance polydithiocarbamate material as a high mechanical performance engineering material and an intelligent deformation material.

[0006] The object of the present invention is achieved by the following solutions:

[0007] A preparation method of a polydithiocarbamate material, comprising the following steps:

[0008] (1) Add a bifunctional amine compound, a base and carbon disulfide to an organic solvent, and stir for reaction;

[0009] (2) Add a bifunctional bromide compound to the reaction system after step (1), stir for reaction, dilute, precipitate, and dry to obtain polydithiocarbamate;

[0010] (3) Hot press the polydithiocarbamate to obtain a polydithiocarbamate material.

[0011] Preferably, the bifunctional amine compound is selected from one or two of the following:

[0012]

[0013] Preferably, the bifunctional bromide compound is selected from one of the following:

[0014]

[0015] Preferably, the molar ratio of the bifunctional amine compound, the bifunctional bromide compound, and carbon disulfide is 1:1 to 1.05:2.2 to 2.5.

[0016] More preferably, the molar ratio of the bifunctional amine compound, the bifunctional bromide compound, and carbon disulfide is 1:1:2.2.

[0017] Preferably, the base in step (1) is potassium carbonate; the molar ratio of the bifunctional amine compound to the base is 1:1.1 to 1.5;

[0018] Preferably, the organic solvent in step (1) is N,N-dimethylformamide; the molar ratio of the bifunctional amine compound to the organic solvent is 1:110 to 150.

[0019] Preferably, the stirring reaction in step (1) is carried out under ice bath conditions; the temperature is 0 °C.

[0020] Preferably, the rotation speed of the stirring reaction in step (1) is 350 - 500 rpm;

[0021] Preferably, the time of the stirring reaction in step (1) is 1 - 3 h.

[0022] Preferably, the carbon disulfide in step (1) is gradually added dropwise to the reaction system under ice bath stirring conditions.

[0023] Preferably, the temperature of the stirring reaction in step (2) is 20 - 30 °C (room temperature);

[0024] Preferably, the rotation speed of the stirring reaction in step (2) is 350 - 500 rpm;

[0025] Preferably, the stirring reaction time in step (2) is 12 to 20 h.

[0026] Preferably, the dilution solvent used for dilution in step (2) is N,N-dimethylformamide;

[0027] Preferably, the precipitant used for precipitation in step (2) is a mixed solvent of n-hexane and absolute ethanol, the volume ratio of n-hexane to absolute ethanol is 4 to 6:1, the stirring speed during the precipitation process is 800 to 1000 rpm, and the stirring time is 1 to 3 h;

[0028] Preferably, the drying in step (2) is baking in a vacuum oven at 60 to 70 °C for 3 to 5 h, and then transferring to a forced-air oven for baking at 80 to 90 °C for 8 to 10 h.

[0029] Preferably, the hot pressing in step (3) includes hot pressing treatment (plate vulcanizer) and cold pressing treatment (cold press);

[0030] More preferably, the temperature of the hot pressing treatment is 90 - 110 °C, the pressure of the hot pressing treatment is 15 - 20 MPa, the time of the hot pressing treatment is 10 - 15 min, the temperature of the cold pressing treatment is room temperature, the pressure of the cold pressing treatment is 15 - 20 MPa, and the time of the cold pressing treatment is 10 - 15 min.

[0031] Preferably, the size of the mold for hot pressing in step (3) is length × width × thickness = 5 cm × 5 cm × 1 mm.

[0032] A polydithiocarbamate material prepared by the above preparation method.

[0033] Preferably, the structural formula of the polydithiocarbamate material is as follows:

[0034]

[0035] Among them, R 1 and R 2 are alkyl, alkoxy or benzyl, R 3 is alkyl or benzyl, m is an integer from 2 to 400, and n is an integer from 2 to 400.

[0036] The application of the above polydithiocarbamate material as a high mechanical property engineering material and a smart deformation material.

[0037] Preferably, the smart deformation material is a shape memory material.

[0038] The mechanism of the present invention is:

[0039] As an excellent new type of dynamic covalent bond, dithiocarbamate endows materials with excellent dynamics and sustainable utilization. Initially, through structural screening, we found that the presence of a benzene ring would cause the polydithiocarbamate material to be brittle, and the presence of an ether chain would cause the polydithiocarbamate material to be soft. Therefore, a series of even-numbered alkyl chain structures with different lengths were decided to be used as the main chain components of this material, and then their properties and applications were further explored. The pure alkyl chain structure as the main chain structure of polydithiocarbamate can improve the mobility and ductility of molecular chains while providing excellent crystallization properties for it. The energy loss generated by the high dynamics of dithiocarbamate and the segmental mobility provided by the alkyl chain structure endow the material with a high elongation at break. The strong crystallinity of the alkyl chain structure during the stretching process provides the material with a high tensile strength and heat resistance, and it is expected to be developed into a high-performance mechanical material. The presence of hydrogen bonds and dynamic covalent bonds greatly improves the dynamic properties of the material, endowing the material with excellent self-healing properties, repeat processing properties and adhesion properties. The reversibility of dithiocarbamate bonds and crystal regions provides the material with excellent deformation and remodeling capabilities, making it have excellent shape memory function and shape remodeling characteristics, and is expected to be developed into an intelligent deformation material.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] (1) The mechanical properties of the polydithiocarbamate material obtained in the present invention are comparable to those of polyurethane materials. The prepared polydithiocarbamate material has tensile-induced strengthening properties, and its tensile strength reaches 134±1.5 MPa after pre-stretching treatment. On the premise of comparable mechanical properties to polyurethane, the polydithiocarbamate material has better dynamic recycling performance and milder recycling conditions, has a self-healing performance with a repair efficiency as high as 90%, and the mechanical strength can still maintain more than 95% of the initial strength after being processed repeatedly three times. The material has good shape memory function and plasticization function, with a high shape fixation rate of 99% and a shape recovery rate of 93%, and belongs to an excellent shape memory material. It has good adhesion to stainless steel substrates, and at the same time has good water resistance and heat-oxygen aging resistance.

[0042] (2) The present invention simultaneously introduces dynamic dithiocarbamate bonds and a pure alkyl chain backbone structure into the polydithiocarbamate system, enabling the material to possess excellent tensile-induced enhancement performance. Its mechanical properties are higher than those of all previously studied polydithiocarbamate materials. Novel and rich functional explorations and property analyses have also been conducted on this material. In addition, the mechanical properties of this polydithiocarbamate material exceed those of most commercial materials. Due to its advantages such as rich and adjustable structure, low preparation cost, commercially available monomers, and high preparation efficiency, it has great potential for commercial applications. Compared with other polymer materials of the same type, the polydithiocarbamate material prepared in this work has better comprehensive properties.

[0043] (3) Through the synergistic effect of dithiocarbamate groups, crystal region structures, and hydrogen bond networks, the polydithiocarbamate material of the present invention combines the advantages of thermosetting materials and thermoplastic materials, enabling the reshaping and fixation of both its temporary shape and permanent shape.

[0044] (4) This invention is a pioneering research in the field of polydithiocarbamates, exploring many functional applications that have never been studied in this material field, and achieving the best level in the comprehensive properties of the material field at the same time. Description of the Drawings

[0045] Figure 1 Schematic structure and stress-strain curves of the polydithiocarbamate materials prepared in Examples 1-4.

[0046] Figure 2 Schematic diagram of the tensile enhancement process of the polydithiocarbamate materials prepared in Examples 3-4.

[0047] Figure 3 Self-healing and reprocessing properties of the polydithiocarbamate materials prepared in Examples 2-4.

[0048] Figure 4 Shape memory curves of the polydithiocarbamate materials prepared in Examples 3-4.

[0049] Figure 5 Alternating combination curves of shape memory and plasticization of the polydithiocarbamate material prepared in Example 4. Detailed Description of the Embodiments

[0050] The present invention will be further described in detail below in conjunction with the embodiments and the drawings, but the embodiments of the present invention are not limited thereto. For those not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0051] The reagents used in the examples can be routinely purchased from the market without special instructions.

[0052] In the following examples and comparative examples, the parts are all molar parts. For example, "30 parts of 1,4-diaminobutane and 33 parts of potassium carbonate" means "the molar ratio of 1,4-diaminobutane to potassium carbonate is 30:33".

[0053] Example 1

[0054] A high-performance polydithiocarbamate material, the structural formula of which is shown in the following figure:

[0055]

[0056] A high-performance polydithiocarbamate material, and its synthesis steps are as follows:

[0057]

[0058] (1) Add 30 parts of 1,4-diaminobutane and 33 parts of potassium carbonate to 3300 parts of N,N-dimethylformamide, place it in an ice bath environment and stir, the rotation speed is 350 rpm, and gradually add 66 parts of carbon disulfide to the system. The ice bath stirring time is 1 h.

[0059] (2) Add 30 parts of 1,4-dibromobutane to the reaction system in step (1), and transfer the reaction to room temperature environment and continue to stir. The room temperature stirring time is 12 h.

[0060] (3) Add 1100 parts of N,N-dimethylformamide to the stock solution after the reaction is completed for dilution, and drop the diluted polydithiocarbamate solution into a mixed solvent of n-hexane and absolute ethanol (the volume ratio of n-hexane to absolute ethanol is 4:1) for stirring precipitation, and the rotation speed is 800 rpm.

[0061] (4) Place the solid product obtained by precipitation in a vacuum oven at 60 °C for baking for 3 - 5 h, and then transfer it to a forced-air oven at 80 °C for baking for 8 h.

[0062] (5) Carry out hot pressing and processing on the dried solid powder, and select a flat vulcanizer and a cold press for processing. The size of the hot pressing die is length × width × thickness = 5 cm × 5 cm × 1 mm. The hot pressing temperature of the flat vulcanizer is 110 °C, the hot pressing pressure is 15 MPa, the hot pressing time is 10 min, the cold pressing pressure of the cold press is 15 MPa, and the cold pressing time is 10 min. Finally, a high-performance polydithiocarbamate material is obtained.

[0063] Example 2

[0064] A high-performance polydithiocarbamate material, the structural formula of which is shown in the following figure:

[0065]

[0066] A high-performance polydithiocarbamate material, and its synthesis steps are as follows:

[0067]

[0068] (1) Add 30 parts of 1,6-hexanediamine and 33 parts of potassium carbonate to 3300 parts of N,N-dimethylformamide, place it in an ice bath environment and stir at a rotation speed of 350 rpm. Gradually add 66 parts of carbon disulfide to the system, and the ice bath stirring time is 1 h.

[0069] (2) Add 30 parts of 1,6-dibromohexane to the reaction system in step (1), move the reaction to room temperature environment and continue stirring, and the room temperature stirring time is 12 h.

[0070] (3) Add 1100 parts of N,N-dimethylformamide to the stock solution after the reaction is completed for dilution. Drop the diluted polydithiocarbamate solution into a mixed solvent of n-hexane and absolute ethanol (the volume ratio of n-hexane to absolute ethanol is 4:1) and stir for precipitation at a rotation speed of 800 rpm.

[0071] (4) Place the solid product obtained by precipitation in a vacuum oven at 60 °C for 3 - 5 h, and then transfer it to a forced-air oven at 80 °C for 8 h.

[0072] (5) Perform hot pressing on the dried solid powder to form a shape. Select a flat vulcanizer and a cold press to process it. The size of the hot pressing mold is length × width × thickness = 5 cm × 5 cm × 1 mm. The hot pressing temperature of the flat vulcanizer is 110 °C, the hot pressing pressure is 15 MPa, the hot pressing time is 10 min, the cold pressing pressure of the cold press is 15 MPa, and the cold pressing time is 10 min. Finally, a high-performance polydithiocarbamate material is obtained.

[0073] Example 3

[0074] A high-performance polydithiocarbamate material, and its structural formula is shown in the following figure:

[0075]

[0076] A high-performance polydithiocarbamate material, and its synthesis steps are as follows:

[0077]

[0078] (1) Add 30 parts of 1,8-octanediamine and 33 parts of potassium carbonate to 3300 parts of N,N-dimethylformamide. Place it in an ice bath environment and stir at a speed of 350 rpm. Gradually add 66 parts of carbon disulfide to the system, and stir in the ice bath for 1 h.

[0079] (2) Add 30 parts of 1,8-dibromooctane to the reaction system in step (1). Move the reaction to room temperature environment and continue to stir. The stirring time at room temperature is 12 h.

[0080] (3) Add 1100 parts of N,N-dimethylformamide to the stock solution after the reaction is completed for dilution. Drop the diluted polydithiocarbamate solution into a mixed solvent of n-hexane and absolute ethanol (the volume ratio of n-hexane to absolute ethanol is 4:1) and stir for precipitation at a speed of 800 rpm.

[0081] (4) Place the solid product obtained by precipitation in a vacuum oven at 60 °C for baking for 3 - 5 h, and then transfer it to a forced-air oven at 80 °C for baking for 8 h.

[0082] (5) Perform hot pressing and processing on the dried solid powder. Select a flat vulcanizer and a cold press for processing. The size of the hot pressing mold is length × width × thickness = 5 cm × 5 cm × 1 mm. The hot pressing temperature of the flat vulcanizer is 100 °C, the hot pressing pressure is 15 MPa, the hot pressing time is 10 min, the cold pressing pressure of the cold press is 15 MPa, and the cold pressing time is 10 min. Finally, a high-performance polydithiocarbamate material is obtained.

[0083] Example 4

[0084] A high-performance polydithiocarbamate material, whose structural formula is shown in the following figure:

[0085]

[0086] A high-performance polydithiocarbamate material, and its synthesis steps are as follows:

[0087]

[0088] (1) Add 30 parts of 1,10-decanediamine and 33 parts of potassium carbonate to 3300 parts of N,N-dimethylformamide. Place it in an ice bath environment and stir at a speed of 350 rpm. Gradually add 66 parts of carbon disulfide to the system, and stir in the ice bath for 1 h.

[0089] (2) Add 30 parts of 1,10-dibromodecane to the reaction system in step (1). Move the reaction to room temperature environment and continue to stir. The stirring time at room temperature is 12 h.

[0090] (3) Add 1100 parts of N,N-dimethylformamide to the stock solution after the reaction to dilute it, and drop the diluted polydithiocarbamate solution into a mixed solvent of n-hexane and absolute ethanol (the volume ratio of n-hexane to absolute ethanol is 4:1) for stirring precipitation at a rotation speed of 800 rpm.

[0091] (4) Place the solid product obtained by precipitation in a vacuum oven at 60 °C for baking for 3 - 5 h, and then transfer it to a forced-air oven at 80 °C for baking for 8 h.

[0092] (5) Perform hot pressing on the dried solid powder to form it, and select a flat vulcanizer and a cold press for processing. The size of the hot pressing mold is length × width × thickness = 5 cm × 5 cm × 1 mm. The hot pressing temperature of the flat vulcanizer is 100 °C, the hot pressing pressure is 15 MPa, the hot pressing time is 10 min, the cold pressing pressure of the cold press is 15 MPa, and the cold pressing time is 10 min. Finally, a high-performance polydithiocarbamate material is obtained.

[0093] Test the comprehensive performance of the materials in the above examples respectively, and the results are as Figures 1-5 shown in Table 1 and Table 2:

[0094] Table 1 Mechanical properties of each example

[0095]

[0096] Table 2 Self-healing, reprocessing, shape memory performance, and adhesion performance of each example

[0097]

[0098] Among them, the experimental parameters of the self-healing efficiency are as follows: the self-healing temperature is 100 °C, and the self-healing time is 1 h;

[0099] The experimental parameters of the reprocessing efficiency are as follows: the processing temperature is 100 °C, and the number of reprocessing times is 3 times.

[0100] Examples 1 - 4 are the high-performance polydithiocarbamate materials of the present invention. The main chain structure of Example 1 is a butyl chain, the main chain structure of Example 2 is a hexyl chain, the main chain structure of Example 3 is an octyl chain, and the main chain structure of Example 4 is a decyl chain. Figure 1It shows that when the number of carbon chains is 4, Example 1 is a pale yellow brittle material with an elongation at break of 18 ± 1.2 MPa and a fracture strength of only 29 ± 0.05%. At this time, the number of carbon chains is short, and the intramolecular hydrogen bond arrangement is relatively dense, making the material brittle. At the same time, the molecular chain is short, and it is difficult to dissipate energy through the crystallization orientation during the stretching process, resulting in a very low elongation at break. When the number of carbon chains is 6, the texture of Example 2 is significantly softer than that of the material in Example 1. However, due to the synergistic effect of weakened hydrogen bonds and crystallization dissipation, the strength of the material is 14 ± 1.9 MPa and the elongation at break is 50 ± 0.11%. When the number of carbon chains increases to 8, the material begins to show a yield point and an enhanced plastic hardening process after yielding. The fracture strength of Example 3 is as high as 36 ± 2.1 MPa, and the elongation at break is as high as 740 ± 0.16%. Since the main chain structure of the long alkyl chain provides a broad crystallization space for the material, sufficient energy dissipation can occur during the stretching process, and the formation of crystal regions also provides a relatively high fracture strength for the material. When the number of carbon chains increases to 10, the crystallization process of the material is further strengthened. The long alkyl chain structure can quickly arrange into regular crystal regions by virtue of its excellent chain movement ability, further enhancing the fracture strength of the material. However, due to the acceleration of the crystallization process, the energy dissipation process is also accelerated. The fracture strength of Example 4 is 42 ± 1.5 MPa, and the elongation at break is 620 ± 0.11%.

[0101] According to the change of Young's modulus, we can also find that with the increase of the alkyl chain in the main chain structure, the Young's modulus of the material gradually decreases. As the alkyl chain becomes longer, the density of the hydrogen bond network decreases. The hydrogen bond network points acting as the hard phase inside the material structure support the stiffness of the entire system. The Young's modulus of this series of linear polydithiocarbamate materials is between 218 MPa and 330 MPa, and with the extension of the alkyl chain in the main chain structure, the Young's modulus of the material gradually decreases. The Young's modulus of Example 1 is 330 MPa, the Young's modulus of Example 2 is 270 MPa, the Young's modulus of Example 3 is 227 MPa, and the Young's modulus of Example 4 is 217 MPa.

[0102] Figure 2Exhibits the tensile enhancement properties of Examples 3-4. Materials such as polyimide and polyglycolic acid can significantly improve their mechanical properties through the method of uniaxial tensile-induced crystallization, and this induced enhancement process is called the step-by-step loading process. We found that after the material undergoes the step-by-step loading process, its mechanical properties have been greatly improved. The step-by-step loading process is briefly introduced as follows: When the material is in an elastic state, a large strain gradient (50%) is used as the deformation termination section of the material. After stretching the material from the initial state to 50%, its stress is unloaded to 0, then the material is stretched to 100%, and its stress is unloaded to 0, then the material is stretched to 150%, and its stress is unloaded to 0, and so on in a cyclic increase until it is stretched to 500%, and then its stress is unloaded to 0. The above process is called the first-step step-cycle tensile enhancement. At this time, the material has changed from the elastic stage to the plastic stage, and a large degree of orientation has occurred inside the material. When the material enters the plastic state, a smaller strain gradient (10%) is used as the deformation termination section of the material. After stretching the plasticized material from the initial state to 10%, its stress is unloaded to 0, then the material is stretched to 20%, and its stress is unloaded to 0, and so on in a cyclic increase until the material is stretched to 70%, and then its stress is unloaded to 0. The above process is called the second-step step-cycle tensile enhancement. When the material undergoes two consecutive steps of step-cycle tensile enhancement, it is transformed from a tough thermoplastic elastomer material into a strong and hard engineering plastic. After Example 3 undergoes the step-by-step loading process, its fracture strength is increased from 36 MPa to 125 ± 0.8 MPa, and its elongation at break is decreased from 736 ± 0.16% to 70 ± 0.62%; after Example 4 undergoes the step-by-step loading process, its fracture strength is increased from 42 MPa to 134 ± 1.5 MPa, and its elongation at break is decreased from 610 ± 0.11% to 114 ± 1.24%.

[0103] Figure 3The cyclic processing performance of the material is demonstrated. First, for the self-healing performance test of Examples 2-4, we selected 100 °C as the self-healing temperature and 1 h, 4 h, and 8 h as the self-healing times of the material respectively to determine its self-healing effect. We found that when the self-healing time was only 1 h, the healing effect of the material was poor, and the exchange process of dynamic bonds was still in the initial stage. When the self-healing time was extended to 4 h, the healing effect of the material was greatly improved. When the self-healing time was finally extended to 8 h, the self-healing efficiency of the material was over 90%, proving that the material is an excellent self-healing material. We respectively explored the repeat processing performance of polydithiocarbamate in Examples 2, 3, and 4. After the failed specimens were cut into pieces with scissors, the fragments of the polydithiocarbamate material were hot-pressed. After hot-pressing at 100 °C, the tensile properties of the newly hot-pressed material were tested. We respectively carried out the repeat processing treatment of "reprocessing into a film after destruction" three times in a row on this series of polydithiocarbamate materials and found that the retention rate of their tensile properties was above 95% after repeat processing. We can find that the mobility of the chain segments greatly affects the repeat processing ability of the material. The main chain structure of Example 2 is a hexyl chain, and the mobility of the chain segments is poor. It can also be seen from the comparison of the stress-strain curves that its repeat processing performance retention is poor. The main chain structure of Example 3 is an octyl chain, and its chain segment mobility is good, so its repeat processing performance retention is also good. The main chain structure of Example 4 is a decyl chain, and its chain segment mobility is the best, and its repeat processing performance retention is also the best.

[0104] Figure 4 The shape memory properties of Examples 3-4 are demonstrated. Through the shape memory single cycle diagrams of Examples 3-4, the deformation recovery rates (R r ) are 99% (Example 3) and 96% (Example 4) respectively, and their deformation retention rates (R f ) are 93% (Example 3) and 92% (Example 4) respectively. In addition, to verify the stability of its deformation function, we carried out the shape memory single cycle process three times in a row on Examples 3-4, proving that the shape memory function of Examples 3-4 has repeatability and stability.

[0105] Figure 5 The combined performance of shape memory / plasticization of Example 4 is demonstrated. After completing the first combination process of shape memory and plastic properties, we continued to carry out one shape memory and one stress relaxation on this basis to complete two consecutive combination processes of shape memory and plastic properties. It is proved that both the temporary shape and the permanent shape of the polydithiocarbamate material can be changed, and it is also proved that we can combine the plastic properties brought by the dynamic exchange of polydithiocarbamate with the shape memory properties based on the elastic deformation of traditional thermosetting materials.

[0106] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A preparation method of a polydithiocarbamate material, characterized in that, It includes the following steps: (1) Add a bifunctional amine compound, a base, and carbon disulfide into an organic solvent, and stir for reaction; (2) Add a bifunctional bromide compound into the system after the reaction in step (1), stir for reaction, dilute, precipitate, and dry to obtain a polydithiocarbamate; (3) Hot press the polydithiocarbamate to obtain a polydithiocarbamate material.

2. The preparation method according to claim 1, wherein The bifunctional amine compound is selected from one or two of the following: The bifunctional bromide compound is selected from one of the following:

3. The preparation method according to claim 1, wherein The molar ratio of the bifunctional amine compound, the bifunctional bromide compound, and carbon disulfide is 1:1 - 1.05:2.2 - 2.

5.

4. The preparation method according to claim 1, wherein The base in step (1) is potassium carbonate; the molar ratio of the bifunctional amine compound to the base is 1:1.1 - 1.5; The organic solvent in step (1) is N,N-dimethylformamide; the molar ratio of the bifunctional amine compound to the organic solvent is 1:110 - 150.

5. The preparation method according to claim 1, wherein, The stirring reaction in step (1) is carried out under ice bath conditions, the rotation speed of the stirring reaction is 350 - 500 rpm, and the time of the stirring reaction is 1 - 3 h.

6. The preparation method according to claim 1, characterized in that, The temperature of the stirring reaction in step (2) is 20 - 30 °C, the rotation speed of the stirring reaction is 350 - 500 rpm, and the time of the stirring reaction is 12 - 20 h.

7. According to the preparation method described in claim 1, it is characterized in that The dilution solvent used for dilution in step (2) is N,N-dimethylformamide; The precipitant used for precipitation in step (2) is a mixed solvent of n-hexane and absolute ethanol, the volume ratio of n-hexane to absolute ethanol is 4 - 6:1, the stirring speed during the precipitation process is 800 - 1000 rpm, and the stirring time is 1 - 3 h; The drying in step (2) is carried out by baking in a vacuum oven at 60 - 70 °C for 3 - 5 h, and then transferred to a forced-air oven for baking at 80 - 90 °C for 8 - 10 h.

8. The preparation method according to claim 1, wherein The hot pressing in step (3) includes hot pressing treatment and cold pressing treatment; The temperature of the hot pressing treatment is 90 - 110 °C, the pressure of the hot pressing treatment is 15 - 20 MPa, the time of the hot pressing treatment is 10 - 15 min, the temperature of the cold pressing treatment is room temperature, the pressure of the cold pressing treatment is 15 - 20 MPa, and the time of the cold pressing treatment is 10 - 15 min.

9. A polydithiocarbamate material prepared by the preparation method according to any one of claims 1 to 8, characterized in that, The structural formula is as follows: Among them, R 1 and R 2 are alkyl, alkoxy or benzyl, R 3 is alkyl or benzyl, m is an integer from 2 to 400, and n is an integer from 2 to 400.

10. Application of the polydithiocarbamate material according to claim 9 as a high mechanical property engineering material and a smart deformation material.

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