Thermoplastic polyurethane elastomer based on bio-based conductive additive and preparation method thereof

Abstract

The invention belongs to the technical field of polyurethane elastomers, and particularly relates to a thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method. The thermoplastic polyurethane elastomer based on the bio-based conductive additive comprises the following components in percentage by mass: 50-75% of a thermoplastic polyurethane elastomer; 1-40% of a bio-based conductive auxiliary agent; 1-10% of a dispersant; and 1-10% of a compatilizer. As a sustainable carbon resource, the bio-based carbon material has the advantages of being simple to prepare, low in cost, environmentally friendly and the like, and compared with other carbon materials, the dispersity of the carbon material can be improved through rich heterogeneous elements of the bio-based carbon material, and the bio-based carbon material has good conductivity. Original bio-based derived carbon has the defects of low porosity, low specific surface area and the like, and the bio-based conductive carbon material which is porous, rich in functional groups, large in specific surface area and low in cost can be obtained through hydrothermal carbonization, high-temperature calcination and activation of an activating agent.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyurethane elastomers, and in particular relates to a thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof. Background Art

[0002] Thermoplastic polyurethane (TPU), a linear block polymer composed of hard and soft segments, is currently widely used in adhesives, coatings, biopharmaceuticals, and composite materials. However, due to the common properties of polymers, TPU materials have poor electrical conductivity, limiting their application in electronics and communications. Therefore, the development of conductive TPU is urgent.

[0003] Chinese patent application CN 108559050 A discloses an antistatic, conductive thermoplastic polyurethane elastomer and its preparation method. The thermoplastic polyurethane elastomer is made from the following raw materials by weight: 30-80 parts of a macromolecular diol, 3-15 parts of a small-molecule diol, 15-55 parts of a diisocyanate, and 0.01-2 parts of single-walled carbon nanotubes. While this invention improves conductivity, the single-walled carbon nanotubes used are mostly derived from graphite. The production of these single-walled carbon nanotubes consumes significant amounts of natural resources, hindering sustainable green development.

[0004] Common conductive carbon materials such as carbon black, graphene, and carbon nanotubes are mostly obtained through various processing techniques using graphite, hydrocarbons, petroleum coke, and asphalt as raw materials. Excessive consumption of fossil fuels can have irreversible impacts on the environment and ecology. Summary of the Invention

[0005] In view of the above deficiencies in the prior art, the object of the present invention is to provide a thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method.

[0006] In order to achieve the above objectives, the technical solutions adopted are: One of the objects of the present invention is to provide a thermoplastic polyurethane elastomer based on a bio-based conductive additive, which comprises the following components by mass percentage: Thermoplastic polyurethane elastomer 50-75%; Bio-based conductive additive 1-40%; Dispersant 1-10%; Compatibilizer 1-10%.

[0007] Preferably, the mass percentage of the thermoplastic polyurethane elastomer is 55-70%, more preferably 60-70%, the mass percentage of the bio-based conductive aid is 20-35%, more preferably 20-30%, more preferably, the thermoplastic polyurethane elastomer is 65%, the bio-based conductive aid is 25%, the dispersant is 5%, and the compatibilizer is 5%.

[0008] Preferably, the thermoplastic polyurethane elastomer is any one or more of polyester thermoplastic polyurethane elastomer, polyether thermoplastic polyurethane elastomer, polycarbonate thermoplastic polyurethane elastomer, polycaprolactone thermoplastic polyurethane elastomer, polyolefin thermoplastic polyurethane elastomer, and aliphatic thermoplastic polyurethane elastomer; the Shore hardness of the thermoplastic polyurethane elastomer is 50A-80D.

[0009] Preferably, the dispersant is a polymeric hyperdispersant, a nonionic wetting dispersant, a cationic wetting dispersant, or other types of dispersants.

[0010] Preferably, the compatibilizer is one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene, maleic anhydride grafted styrene block copolymer, maleic anhydride grafted ethylene-octene copolymer, maleic anhydride grafted ethylene-vinyl acetate copolymer, maleic anhydride grafted EPDM rubber, and amino-terminated styrene block copolymer, more preferably maleic anhydride grafted styrene block copolymer and / or maleic anhydride grafted ethylene-octene copolymer.

[0011] Preferably, the method for preparing the bio-based conductive additive comprises the following steps: S1: The bio-based carbon source is repeatedly rinsed with pure water and ethanol and then loaded into a hydrothermal reactor. The reactor containing the carbon source is placed in a constant temperature blower at 170-190 ° C for 15-24 hours to complete the initial carbonization. The obtained sample is washed with deionized water several times until the wastewater is colorless, placed in a blower to dry, and then ground evenly to obtain a preliminary carbonized product; S2: Grind the preliminary carbonized product and the activator in a weight ratio of 1:(1-10) until the mixture is uniform, place the mixture in a tube furnace, and calcine at 700-900 °C in an inert atmosphere for 1-8 h to obtain an intermediate carbonized product; S3: The intermediate carbonization product is washed with dilute hydrochloric acid and deionized water until it becomes neutral, and then placed in an oven for drying to obtain a bio-based conductive additive.

[0012] Preferably, the bio-based carbon source in S1 is any one or more of grapefruit peel, fungus, shiitake mushroom, cabbage, kiwi, sterculia lychnophora, persimmon, mango peel, cotton, watermelon flesh, shrimp shell, crab shell, rice husk, wheat straw, corn stalk, cherry petal, tea, silk cocoon, fish scale, and loofah.

[0013] More preferably, it is any one or more of fungus, kiwi fruit, puffed sea, persimmon, grapefruit peel, cotton, rice husk, wheat straw, and corn straw.

[0014] The beneficial effect of adopting the above-mentioned preferred technical solution is that: the materials such as wood ear, kiwi fruit, puffed sea, persimmon, grapefruit peel, cotton, rice husk, wheat straw and corn stalk are preferred because compared with other materials, these materials are easier to prepare carbon materials with nano-scale morphology. Other materials can also be used to prepare conductive carbon materials, but the size will be larger, which will affect the conductive properties.

[0015] Preferably, the activator in S2 is any one or more of potassium hydroxide, sodium hydroxide, phosphoric acid, potassium carbonate, ferric chloride, calcium chloride, ferric ammonium citrate, potassium ferrate, potassium phosphate, zinc chloride, sodium bicarbonate, and potassium bicarbonate.

[0016] Preferably, the bio-based conductive additive has a morphology of nanosheets, nanotubes, nanofibers or nanospheres, wherein the diameter of the nanofibers is 50-500 nm and the thickness of the nanosheets is 10-100 nm.

[0017] A second object of the present invention is to provide a method for preparing a thermoplastic polyurethane elastomer based on a bio-based conductive additive, comprising the following steps: S1: Add thermoplastic polyurethane elastomer, bio-based conductive additive, dispersant, and compatibilizer according to mass percentage into a high-speed mixer and stir for 10-20 minutes at a stirring speed of 300-600 rpm to obtain a mixed material; S2: feeding the mixed material into the main feeding port of a twin-screw extruder, and performing shearing, melting, extrusion, and granulation to obtain the bio-based conductive additive-based thermoplastic polyurethane elastomer.

[0018] Compared with the prior art, the present invention offers the following advantages: the bio-based conductive additive is primarily composed of carbon material, which can be carbonized into carbon nanosheets, nanotubes, nanofibers, and nanospheres, depending on the precursor morphology. Different bio-based precursor materials contain varying heteroatoms (primarily N and O), which are retained in the bio-based carbon material after carbonization. Through the combined action of carbonization and an activator, the bio-based additive contains nitrogen in various forms (pyridinic, pyrrolic, and graphitic nitrogen), CO, C=O, and -COOH. The introduction of heteroatoms improves the conductivity and dispersibility of the material. Furthermore, compared to graphite and carbon nanotubes, the bio-based additive offers the advantages of resource conservation and reduced environmental pollution. The bio-based conductive additive has a large specific surface area, allowing a small amount to form a conductive network, thereby improving the conductivity of the polyurethane material.

[0019] As a sustainable carbon resource, bio-based carbon materials offer advantages such as simple preparation, low cost, easy availability, environmental friendliness, and sustainable development. Compared to other carbon materials, the rich heterogeneous elements inherent in bio-based materials can improve their dispersibility. Furthermore, bio-based carbon materials also possess good electrical conductivity. Raw bio-based derived carbon has disadvantages such as low porosity and low specific surface area. Through hydrothermal carbonization, high-temperature calcination, and activation with an activator, porous, functional group-rich, large specific surface area, and low-cost bio-based conductive carbon materials can be obtained. DETAILED DESCRIPTION

[0020] The present invention is described below with reference to examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.

[0021] Preparation Example 1 This preparation example provides a bio-based conductive carbon material, which is obtained by the following preparation method: 1 g of dried wood ear mushroom was soaked in distilled water for 2 hours. The soaked wood ear mushroom and distilled water were transferred to a 50 mL hydrothermal reactor. The reactor containing the carbon source was kept at 190°C in a constant temperature blower for 24 hours to complete the initial carbonization. The resulting sample was washed multiple times with deionized water until the wastewater was colorless. The sample was then dried in a blower and ground uniformly to obtain a preliminary carbonized product. The preliminary carbonized product was then mixed with the activator KOH in a 1:3 mass ratio and calcined at 800°C in an inert atmosphere for 2 hours to obtain an intermediate carbonized product. The intermediate carbonized product was washed with dilute hydrochloric acid and deionized water until neutral, dried in an oven, and ground to obtain the final bio-based conductive additive.

[0022] Preparation Example 2 This preparation example provides a bio-based conductive carbon material, which is obtained by the following preparation method: Sterculia lychnophora was soaked in distilled water for 2 hours. The core and peel were removed. The soaked Sterculia lychnophora and distilled water were transferred to a 50 mL hydrothermal reactor. The reactor containing the carbon source was kept at 180°C in a constant temperature blower for 15 hours to complete the initial carbonization. The resulting sample was washed several times with deionized water until the wastewater was colorless. The sample was then dried in a blower and ground uniformly to obtain a preliminary carbonized product. The preliminary carbonized product was then mixed with the activator ammonium ferric citrate in a mass ratio of 1:5. After mixing, the mixture was calcined at 800°C in an inert atmosphere for 2 hours to obtain an intermediate carbonized product. The intermediate carbonized product was washed with dilute hydrochloric acid and deionized water until neutral, dried in an oven, and ground to obtain the final bio-based conductive additive.

[0023] Preparation Example 3 This preparation example provides a bio-based conductive carbon material, which is obtained by the following preparation method: Kiwifruit was peeled, cut into pieces, and transferred with distilled water to a 50 mL hydrothermal reactor. The reactor, containing the carbon source, was kept at 180°C in a constant-temperature blower for 15 hours to complete initial carbonization. The resulting sample was washed multiple times with deionized water until the wastewater was colorless, dried in a blower, and then ground uniformly to obtain a preliminary carbonized product. The preliminary carbonized product was then mixed with the activator potassium ferrate in a 1:1 mass ratio and calcined at 800°C in an inert atmosphere for 2 hours to obtain an intermediate carbonized product. The intermediate carbonized product was washed with dilute hydrochloric acid and deionized water until neutral and then dried in an oven to obtain the final bio-based conductive additive.

[0024] Preparation Example 4 This preparation example provides a bio-based conductive carbon material. The only difference from Preparation Example 1 is that the soaked wood ear mushroom is replaced with cotton and the activator is replaced with ferric chloride. The remaining preparation methods are the same as those in Preparation Example 1, ultimately yielding a bio-based conductive additive.

[0025] Preparation Example 5 This preparation example provides a bio-based conductive carbon material. The only differences from Preparation Example 1 are that the soaked wood ear mushroom is replaced with grapefruit peel and the activator is replaced with zinc chloride. The remaining preparation methods are the same as those in Preparation Example 1, ultimately yielding a bio-based conductive additive.

[0026] Preparation Example 6 This preparation example provides a bio-based conductive carbon material, which differs from Preparation Example 1 only in that the expanded wood ear replaces the corn stalks. The remaining preparation methods are the same as those in Preparation Example 1, ultimately yielding a bio-based conductive additive.

[0027] Comparative Preparation Example 1 This comparative preparation example provides a bio-based conductive carbon material, which differs from Preparation Example 1 only in that no KOH activator is added. The other preparation methods are the same as Preparation Example 1, and finally a comparative bio-based conductive additive 1 is obtained.

[0028] Comparative Preparation Example 2 This comparative preparation example provides a bio-based conductive carbon material, which differs from Preparation Example 1 only in that the calcination temperature is changed to 600°C. The other preparation methods are the same as Preparation Example 1, and finally a comparative bio-based conductive additive 2 is obtained.

[0029] Comparative Preparation Example 3 This comparative preparation example provides a bio-based conductive carbon material, which differs from Preparation Example 1 only in that the calcination temperature is changed to 1000°C. The other preparation methods are the same as Preparation Example 1, and the comparative bio-based conductive additive 3 is finally obtained.

[0030] Comparative Preparation Example 4 This comparative preparation example provides a bio-based conductive carbon material, which is obtained by the following preparation method: Dried wood ear mushrooms were mixed with the activator KOH in a 1:3 mass ratio and calcined at 800°C for 2 h in an inert atmosphere to produce a carbonized product. The carbonized product was then washed with dilute hydrochloric acid and deionized water until neutral, oven-dried, and ground to obtain comparative bio-based conductive agent 4.

[0031] Comparative Preparation Example 5 This comparative preparation example provides a bio-based conductive carbon material, which is obtained by the following preparation method: Soak 1 g of dried wood ear mushroom in distilled water for 2 hours. The soaked wood ear mushroom, KOH, and distilled water were transferred to a 50 mL hydrothermal reactor. The reactor, containing the carbon source, was incubated at 190°C in a constant-temperature blower for 24 hours to complete carbonization. The resulting sample was washed multiple times with deionized water until the wastewater was colorless, dried in a blower, and then ground uniformly to obtain comparative bio-based conductive additive 5.

[0032] Example 1 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 65% Fungus conductive additive 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The method for preparing a thermoplastic polyurethane elastomer based on a bio-based conductive additive is as follows: The four materials were placed in a high-speed mixer and stirred at 400 rpm for 15 minutes to obtain a mixture. The mixture was then fed into the main feed port of a twin-screw extruder and subjected to shearing, melting, extrusion, and granulation to obtain a thermoplastic polyurethane elastomer containing a bio-based conductive additive. The bio-based conductive additive was the carbon material obtained in Preparation Example 1, and the polyester TPU used had a hardness of 95A.

[0033] Example 2 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyether TPU 65% Sterculia lychnophora conductive additive 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Preparation Example 2, the hardness of the polyether TPU is 50A, and the contents of other components and the preparation method are the same as in Example 1.

[0034] Example 3 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polycarbonate TPU 65% Kiwi conductive additive 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Preparation Example 3, the hardness of the polycarbonate TPU is 70D, and the contents of other components and the preparation method are the same as in Example 1.

[0035] Example 4 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polycaprolactone TPU 65% Cotton conductive additive 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Preparation Example 4, the hardness of the polycaprolactone TPU is 80A, and the contents of other components and the preparation method are the same as in Example 1.

[0036] Example 5 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyolefin TPU 65% Grapefruit peel conductive additive 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Preparation Example 5, the hardness of the polyolefin-type TPU is 65A, and the contents of other components and the preparation method are the same as in Example 1.

[0037] Example 6 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Aliphatic TPU 65% Corn stalk conductive additive 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Preparation Example 6, the hardness of the aliphatic TPU is 60A, and the contents of other components and the preparation method are the same as in Example 1.

[0038] Example 7 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 50% Fungus conductive additive 40% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The four materials were placed in a high-speed mixer and stirred at 400 rpm for 15 minutes to obtain a mixture. The mixture was then fed into the main feed port of a twin-screw extruder and subjected to shearing, melting, extrusion, and granulation to obtain a thermoplastic polyurethane elastomer containing a bio-based conductive additive. The bio-based conductive additive was the carbon material obtained in Preparation Example 1, and the polyester TPU used had a hardness of 95A.

[0039] Example 8 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 75% Fungus conductive additive 15% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 7 is that the ratio of polyester TPU to bio-based conductive additive is adjusted. The other component contents and preparation methods are the same as those in Example 7.

[0040] Example 9 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 55% Fungus conductive additive 35% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 7 is that the ratio of polyester TPU to bio-based conductive additive is adjusted. The other component contents and preparation methods are the same as those in Example 7.

[0041] Example 10 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 60% Fungus conductive additive 30% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 7 is that the ratio of polyester TPU to bio-based conductive additive is adjusted. The other component contents and preparation methods are the same as those in Example 7.

[0042] Example 11 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 70% Fungus conductive additive 20% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 7 is that the ratio of polyester TPU to bio-based conductive additive is adjusted. The other component contents and preparation methods are the same as those in Example 7.

[0043] Comparative Example 1 A thermoplastic polyurethane elastomer based on a carbon black conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 65% Carbon black 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The preparation method of the thermoplastic polyurethane elastomer based on the conductive additive is as follows: The four materials were placed in a high-speed mixer and stirred at 400 rpm for 15 minutes to obtain a mixture. The mixture was then fed into the main feed port of a twin-screw extruder. After shearing, melting, extrusion, and pelletization, a thermoplastic polyurethane elastomer containing a carbon black conductive additive was obtained. The polyester TPU had a hardness of 95A.

[0044] Comparative Example 2 This comparative example provides a thermoplastic polyurethane elastomer based on a single-walled carbon nanotube conductive agent. The only difference from Comparative Example 1 is that the conductive agent is replaced by single-walled carbon nanotubes, and the other component contents and preparation methods are the same as those of Comparative Example 1.

[0045] Comparative Example 3 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 65% Comparison of bio-based conductive additive 1 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Comparative Preparation Example 1, and the other component contents and preparation methods are the same as in Example 1.

[0046] Comparative Example 4 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 65% Comparison of bio-based conductive additive 2 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Comparative Preparation Example 2, and the other component contents and preparation methods are the same as in Example 1.

[0047] Comparative Example 5 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 65% Comparison of bio-based conductive additives 3 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Comparative Preparation Example 3, and the other component contents and preparation methods are the same as in Example 1.

[0048] Comparative Example 6 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 65% Comparison of bio-based conductive additives 4 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Comparative Preparation Example 4, and the other component contents and preparation methods are the same as in Example 1.

[0049] Comparative Example 7 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 65% Comparison of bio-based conductive additives 5 25% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 1 is that the bio-based conductive agent is replaced by the carbon material obtained in Comparative Preparation Example 5, and the other component contents and preparation methods are the same as in Example 1.

[0050] Comparative Example 8 A thermoplastic polyurethane elastomer based on a bio-based conductive additive and a preparation method thereof, comprising the following components by mass percentage: Polyester TPU 85% Fungus conductive additive 5% Dispersant: Polyvinylpyrrolidone 5% Compatibilizer: Maleic anhydride grafted polypropylene 5% The only difference from Example 7 is that the ratio of polyester TPU to bio-based conductive additive is adjusted. The other component contents and preparation methods are the same as those in Example 7.

[0051] Table 1. Raw material composition of each example (unit: mass percentage)

[0052] Table 2. Raw material composition of each comparative example (unit: mass percentage)

[0053] Table 3. Test results of various embodiments and comparative examples

[0054] From the data in Table 3, it can be seen that the surface resistance of the thermoplastic polyurethane elastomer prepared by the solution of the present invention can be as low as 2.2×10 4 Ω, meeting the requirements of downstream customers for conductive properties.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermoplastic polyurethane elastomer based on a bio-based conductive additive, characterized in that: Calculated by mass percentage, it includes the following components: Thermoplastic polyurethane elastomer 50-75%; Bio-based conductive additive 1-40%; Dispersant 1-10%; Compatibilizer 1-10%.

2. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 1, characterized in that: The mass percentage of the thermoplastic polyurethane elastomer is 55-70%, and the mass percentage of the bio-based conductive additive is 20-35%.

3. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 1 or 2, characterized in that: The thermoplastic polyurethane elastomer is any one or more of polyester thermoplastic polyurethane elastomer, polyether thermoplastic polyurethane elastomer, polycarbonate thermoplastic polyurethane elastomer, polycaprolactone thermoplastic polyurethane elastomer, polyolefin thermoplastic polyurethane elastomer, and aliphatic thermoplastic polyurethane elastomer; the Shore hardness of the thermoplastic polyurethane elastomer is 50A-80D.

4. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 1, characterized in that: The dispersant is one of a polymeric superdispersant, a nonionic wetting dispersant, and a cationic wetting dispersant; the compatibilizer is one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene, maleic anhydride grafted styrene block copolymer, maleic anhydride grafted ethylene-octene copolymer, maleic anhydride grafted ethylene-vinyl acetate copolymer, maleic anhydride grafted ethylene propylene diene monomer rubber, and amino-terminated styrene block copolymer.

5. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 1, characterized in that: The preparation method of the bio-based conductive additive comprises the following steps: S1: After washing the bio-based carbon source, place it in a hydrothermal reactor, place it in a constant temperature blower at 170-190 ° C for 15-24 hours to complete the initial carbonization, wash it with deionized water until the wastewater is colorless, place it in a blower to dry it, and grind it evenly to obtain the initial carbonization product; S2: Grind the preliminary carbonized product and the activator in a weight ratio of 1:(1-10) until the mixture is uniform, place the mixture in a tube furnace, and calcine at 700-900 °C in an inert atmosphere for 1-8 h to obtain an intermediate carbonized product; S3: washing the intermediate carbonization product with dilute hydrochloric acid and deionized water until it is neutral, and drying it in an oven to obtain the bio-based conductive additive.

6. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 5, characterized in that: The bio-based carbon source in S1 is any one or more of grapefruit peel, fungus, shiitake mushroom, cabbage, kiwi fruit, sterculia lychnophora, persimmon, mango peel, cotton, watermelon flesh, shrimp shell, crab shell, rice husk, wheat straw, corn straw, cherry petals, tea leaves, silk cocoons, fish scales, and loofah pulp.

7. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 6, characterized in that: The bio-based carbon source in S1 is any one or more of fungus, kiwi fruit, puffed sea, persimmon, grapefruit peel, cotton, rice husk, wheat straw, and corn straw.

8. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 5, characterized in that: The activator in S2 is any one or more of potassium hydroxide, sodium hydroxide, phosphoric acid, potassium carbonate, ferric chloride, calcium chloride, ferric ammonium citrate, potassium ferrate, potassium phosphate, zinc chloride, sodium bicarbonate, and potassium bicarbonate.

9. The bio-based conductive additive-based thermoplastic polyurethane elastomer according to claim 5, characterized in that: The bio-based conductive additive has a morphology of nanosheets, nanotubes, nanofibers or nanospheres, wherein the diameter of the nanofibers is 50-500 nm and the thickness of the nanosheets is 10-100 nm.

10. The method for preparing a thermoplastic polyurethane elastomer containing a bio-based conductive additive according to any one of claims 1 to 9, wherein: The following steps are involved: S1: Stirring the thermoplastic polyurethane elastomer, bio-based conductive additive, dispersant, and compatibilizer according to the mass percentage at a stirring speed of 300-600 rpm for 10-20 minutes to obtain a mixture; S2: The mixed material is extruded and granulated through a twin-screw extruder to obtain the bio-based conductive additive-based thermoplastic polyurethane elastomer.

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