Waterborne polyurethane and silica gel composite biomimetic material as well as preparation method and application thereof

Abstract

The invention discloses a waterborne polyurethane and silica gel composite biomimetic material and a preparation method and application thereof, and belongs to the technical field of biomimetic skin, the biomimetic material comprises a silica gel layer and a polyurethane layer, the silica gel layer is made of two-component silica gel, the polyurethane layer is made of double-bond end-capped waterborne polyurethane, and the two-component silica gel is made of polyurethane. The preparation method of the biomimetic material comprises the following steps: spraying double-bond end-capped waterborne polyurethane into a mold, heating and drying to obtain a polyurethane layer; spraying a platinum catalyst on the surface of the polyurethane layer, then uniformly mixing the component A and the component B of the two-component silica gel, pouring the mixture into a mold, oscillating, paving, curing and forming to obtain the waterborne polyurethane and silica gel composite biomimetic material. The biomimetic material has the characteristics of high peel strength, good environmental protection performance, good folding resistance, high wear resistance, good heat resistance and the like, particularly has a skin-friendly touch feeling like a baby, and has a wide application prospect in the aspects of artificial skin, soft robots, wearable equipment, artificial limb epidermis and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of bionic skin, and specifically relates to a waterborne polyurethane and silica gel composite bionic material and a preparation method and application thereof. Background Art

[0002] As the demand for smart wearable devices and soft robot skin increases, the market for developing materials with similar performance to human skin becomes more and more urgent. Since many wearable devices and soft robots currently use silicone as the soft material, the surface of this material has a poor touch, is easily contaminated, and is difficult to clean, it has obvious disadvantages in terms of application and human-machine experience.

[0003] At present, the post-treatment of silicone at home and abroad adopts solvent-based silicone feel agent and other treatment agents. Because this treatment agent contains strong solvents, it has poor environmental performance and poor bonding with silicone. It is easy to fall off and crack in the later application process. Therefore, the development of materials that can be firmly bonded with silicone and have good skin-friendly feeling is an important research field. Summary of the invention

[0004] The purpose of the present invention is to provide a waterborne polyurethane and silicone composite bionic material and a preparation method and application thereof, so as to solve the problem that the existing bionic skin material silicone has poor adhesion with skin-friendly materials.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a water-based polyurethane and silicone composite bionic material, which includes a silicone layer and a polyurethane layer. The material of the silicone layer includes two-component silicone, and the material of the polyurethane layer includes double-bond terminated water-based polyurethane, and the silicone layer and the polyurethane layer are bonded together through a chemical reaction under the action of a platinum catalyst.

[0006] Furthermore, the two-component silicone is addition-type AB two-component platinum silicone.

[0007] Furthermore, the raw materials of the double-bond terminated waterborne polyurethane include isocyanate, polyol, hydrophilic chain extender, small molecule chain extender, end-capping agent, neutralizing agent and post-chain extender.

[0008] Furthermore, the end-capping agent is a compound containing a hydroxyl group and a double bond. Preferably, the end-capping agent is an acrylate compound containing a monohydroxyl group.

[0009] Furthermore, the end-capping agent is at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate and hydroxyethyl acrylate.

[0010] Furthermore, the isocyanate is at least one of isophorone diisocyanate (IPDI), 4,4-dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), toluene-2,4-diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

[0011] Furthermore, the polyol is at least one of polyether polyol (PPG series), polytetramethylene glycol (PTMG series), polyester polyol and polycarbonate polyol.

[0012] Furthermore, the hydrophilic chain extender is at least one of dimethylol propionic acid, dimethylol butyric acid and sulfonate type hydrophilic chain extenders.

[0013] Furthermore, the sulfonate type hydrophilic chain extender is a sulfonate chain extender containing active hydrogen, especially a sulfonate type hydrophilic chain extender containing amino groups, specifically at least one of sodium ethylenediamineethanesulfonate, 1,3-diaminobenzene-4,6-disulfonic acid and diaminobenzenesulfonate.

[0014] Furthermore, the small molecule chain extender is at least one of 2-methyl-1,3-propanediol (MPO), 1,4-butanediol (BDO), cyclohexanedimethanol (CHDM) and trimethylolpropane (TMP).

[0015] Furthermore, the neutralizing agent is at least one of triethylamine, ammonia water and sodium hydroxide, preferably triethylamine.

[0016] Furthermore, the post-chain extender is at least one of ethylenediamine, hexamethylenediamine and isophoronediamine.

[0017] Furthermore, the preparation method of the double-bond terminated waterborne polyurethane comprises the following steps: Add polyol and isocyanate into a flask, stir and react at 85-95°C for 2-3h, then add hydrophilic chain extender, small molecule chain extender and diluent, stir and react at 70-85°C for 2-3h, then add catalyst and diluent, cool to 65-75°C and continue to react for 3-5h, add end-capping agent, keep warm and react for 1-2h to obtain prepolymer, cool the prepolymer to 40-50°C, add diluent and neutralizing agent, react for 3-5min, then cool to 10-15°C, add deionized water, stir and disperse, then add post-chain extender to carry out post-chain extension reaction, then remove diluent to obtain the double-bond terminated waterborne polyurethane.

[0018] Furthermore, in the above preparation process, the mass ratio of polyol, isocyanate, hydrophilic chain extender, small molecule chain extender, catalyst, neutralizer, deionized water and post-chain extender is 120-159.2: 22.2-33: 4.27-5.9: 0.74: 0.28-0.35: 3.22: 279-350: 0.92.

[0019] Furthermore, the ratio of the polyol to the isocyanate satisfies the isocyanate index (NCO / OH ratio) of 2-2.8. The polyurethane film obtained under this ratio has a relatively soft hardness and is easy to combine with the silicone layer.

[0020] Furthermore, the amount of the end-capping agent is 0.5-1.5% of the total mass of isocyanate, polyol, hydrophilic chain extender, small molecule chain extender, neutralizer and post-chain extender. If the end-capping agent content is too little, the obtained double-bond terminated waterborne polyurethane cannot fully react with the two-component silicone, resulting in poor bonding between the two. If the end-capping agent content is too much, the original two-component silicone functional group ratio will be unbalanced, thereby affecting the curing and molding of the silicone.

[0021] Furthermore, the catalyst is an organic bismuth catalyst, preferably at least one of BCAT-E28A and BCAT-E16.

[0022] Furthermore, the diluent is acetone and / or butanone.

[0023] The second aspect of the present invention provides a method for preparing a waterborne polyurethane and silicone composite bionic material, comprising the following steps: S1, spraying the double-bond terminated waterborne polyurethane into a polytetrafluoroethylene mold, heating and drying to obtain a polyurethane layer; S2, spraying a platinum catalyst onto the surface of the polyurethane layer, then evenly mixing component A and component B of the two-component silicone, pouring them into a polytetrafluoroethylene mold, oscillating and flattening them, and curing and molding them to obtain the waterborne polyurethane and silicone composite bionic material.

[0024] Furthermore, in step S1, the heating temperature is 80-120° C., the heating time is 3-10 min, and the thickness of the polyurethane layer is 0.1-0.3 mm.

[0025] Furthermore, the platinum catalyst is at least one of Speier's catalyst, Karstedt's catalyst and Ashby's catalyst. Preferably, the platinum catalyst is KP25 catalyst of Shanghai Neutron Star Chemical Technology Co., Ltd.

[0026] Furthermore, the spraying amount of platinum catalyst in step S2 is 12-20 g / m 2 , preferably 16g / m 2If the amount of catalyst used is too little, the polyurethane layer cannot be fully combined with the two-component silicone. If the amount of catalyst used is too much, the polyurethane layer and the two-component silicone react too violently, which can easily cause too much heat on the surface of the polyurethane layer and damage the film-forming resin.

[0027] Furthermore, the amount of two-component silica gel used in step S2 is 15-28 kg / m 2 , preferably 20kg / m 2 .

[0028] Furthermore, the curing molding temperature in step S2 is 20-30°C. If the temperature is too low, the polymerization speed may be too slow, thereby affecting the reaction molding of the polyurethane layer and the two-component silicone. If the temperature is too high, the two-component silicone body may react too quickly, resulting in poor bonding between the two-component silicone and the polyurethane layer.

[0029] The third aspect of the present invention provides the application of the above-mentioned water-based polyurethane and silicone composite bionic material in artificial skin, soft robots, wearable devices and prosthetic epidermis.

[0030] Beneficial effects of the present invention: 1. The present invention provides a waterborne polyurethane and silicone composite bionic material, which is formed by bonding double-bond-terminated waterborne polyurethane and two-component silicone through chemical reaction under the action of a platinum catalyst, and has a double-layer structure, including a silicone layer and a polyurethane layer, wherein the polyurethane layer exhibits the touch of baby skin, and the silicone layer provides a soft and elastic fleshy feel, which not only solves the problem that the silicone surface energy is low and difficult to bond, but also retains the soft feel of silicone after molding and has a skin-friendly touch like that of a baby's skin; in addition, the bionic material has a peel strength of up to 5N / 3cm (the tear strength of silicone is only 5N), a folding resistance of up to 100,000 times at room temperature, a folding resistance of up to 50,000 times at low temperature, and a Martindale wear resistance of up to 100,000 times, and has the characteristics of high peel strength, good environmental performance, good folding resistance, high wear resistance, good heat resistance, etc., and has broad application prospects in artificial skin, soft robots, wearable devices, prosthetic epidermis, etc.

[0031] 2. The present invention controls the ratio of polyol to isocyanate in the preparation process of double-bond terminated waterborne polyurethane to satisfy the isocyanate index (NCO / OH ratio) of 2-2.8. The hardness of the polyurethane film obtained under this ratio is relatively soft, which is conducive to its collision reaction with silica gel. The obtained polyurethane film layer is easy to combine with the silica gel layer. Otherwise, the isocyanate index is too high, the hardness of the polyurethane film layer is relatively high, and the bonding with silica gel is poor.

[0032] 3. The present invention strictly controls the amount of the end-capping agent in the preparation process of the double-bond terminated waterborne polyurethane. Otherwise, if the end-capping agent content is too little, the obtained double-bond terminated waterborne polyurethane cannot fully react with the two-component silica gel, resulting in poor binding between the two. If the end-capping agent content is too much, the original two-component silica gel functional group ratio will be unbalanced, thereby affecting the curing and molding of the silica gel.

[0033] 4. The present invention strictly controls the amount of platinum catalyst used in the preparation process of bionic materials. Otherwise, if the amount of platinum catalyst used is too little, the polyurethane layer cannot be fully combined with the two-component silicone, resulting in poor bonding between the two. If the amount of platinum catalyst used is too much, the polyurethane layer and the two-component silicone react too violently, which can easily cause too much heat to accumulate on the surface of the polyurethane layer and damage the film-forming resin.

[0034] 5. The present invention strictly controls the curing temperature of the bionic material. Otherwise, if the temperature is too low, the polymerization speed will be too slow, thereby affecting the reaction molding of the polyurethane layer and the two-component silicone. If the temperature is too high, the two-component silicone body will react too quickly, resulting in poor bonding between the two-component silicone and the polyurethane layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described below in conjunction with the accompanying drawings.

[0036] Figure 1 1 is a graph showing the peel strength test results of the waterborne polyurethane and silicone composite biomimetic materials obtained in Examples 1 and 4 of the present invention; Figure 2 1 is a graph showing the peel strength test results of the waterborne polyurethane and silicone composite biomimetic materials obtained in Examples 2 and 7 of the present invention; Figure 3 3 is a graph showing the peel strength test results of the waterborne polyurethane and silicone composite biomimetic materials obtained in Examples 3 and 5 of the present invention; Figure 4 1 is a graph showing the peel strength test results of the waterborne polyurethane and silicone composite biomimetic materials obtained in Examples 6 and 8 of the present invention; Figure 5 It is a graph showing the peeling strength test results of the waterborne polyurethane and silicone composite bionic materials obtained in Comparative Examples 1 to 8 of the present invention. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] In the present application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, a~b (i.e. a and b), a~c, b~c, or a~b~c, where a, b, c can be single or multiple, respectively.

[0039] The terms used in the embodiments of the present application are only for the purpose of describing specific implementation rules, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the implementation rules of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0040] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0041] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0042] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0043] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0044] The existing bionic skin material silicone has poor adhesion to skin-friendly materials. In order to solve the above problem to a certain extent, the first aspect of the present application provides a water-based polyurethane and silicone composite bionic material, which includes a silicone layer and a polyurethane layer. The material of the silicone layer includes two-component silicone, and the material of the polyurethane layer includes double-bond terminated water-based polyurethane, and the silicone layer and the polyurethane layer are bonded together through a chemical reaction under the action of a platinum catalyst.

[0045] In some embodiments, the two-component silicone is an addition-type AB two-component platinum silicone.

[0046] In some embodiments, the raw materials of the double-bond terminated waterborne polyurethane include isocyanate, polyol, hydrophilic chain extender, small molecule chain extender, end-capping agent, neutralizing agent and post-chain extender.

[0047] In some embodiments, the end-capping agent is a compound having a hydroxyl group and a double bond. Preferably, the end-capping agent is an acrylate compound having a monohydroxyl group.

[0048] In some embodiments, the end-capping agent is at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and hydroxyethyl acrylate.

[0049] In some embodiments, the isocyanate is at least one of isophorone diisocyanate (IPDI), 4,4-dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), toluene-2,4-diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

[0050] In some embodiments, the polyol is at least one of polyether polyol (PPG series), polytetramethylene glycol (PTMG series), polyester polyol and polycarbonate polyol.

[0051] In some embodiments, the hydrophilic chain extender is at least one of dimethylol propionic acid, dimethylol butyric acid, and a sulfonate type hydrophilic chain extender.

[0052] In some embodiments, the sulfonate type hydrophilic chain extender is a sulfonate chain extender containing active hydrogen, especially a sulfonate type hydrophilic chain extender containing amino groups, specifically at least one of sodium ethylenediamineethanesulfonate, 1,3-diaminobenzene-4,6-disulfonic acid and diaminobenzenesulfonate.

[0053] In some embodiments, the small molecule chain extender is at least one of 2-methyl-1,3-propanediol (MPO), 1,4-butanediol (BDO), cyclohexanedimethanol (CHDM) and trimethylolpropane (TMP).

[0054] In some embodiments, the neutralizing agent is at least one of triethylamine, aqueous ammonia and sodium hydroxide, preferably triethylamine.

[0055] In some embodiments, the post-chain extender is at least one of ethylenediamine, hexamethylenediamine, and isophoronediamine.

[0056] In some embodiments, the method for preparing the double-bond terminated waterborne polyurethane comprises the following steps: Add polyol and isocyanate into a flask, stir and react at 85-95°C for 2-3h, then add hydrophilic chain extender, small molecule chain extender and diluent, stir and react at 70-85°C for 2-3h, then add catalyst and diluent, cool to 65-75°C and continue to react for 3-5h, add end-capping agent, keep warm and react for 1-2h to obtain prepolymer, cool the prepolymer to 40-50°C, add diluent and neutralizing agent, react for 3-5min, then cool to 10-15°C, add deionized water, stir and disperse, then add post-chain extender to carry out post-chain extension reaction, then remove diluent to obtain the double-bond terminated waterborne polyurethane.

[0057] In some embodiments, in the above preparation process, the mass ratio of polyol, isocyanate, hydrophilic chain extender, small molecule chain extender, catalyst, neutralizer, deionized water and post-chain extender is 120-159.2: 22.2-33: 4.27-5.9: 0.74: 0.28-0.35: 3.22: 279-350: 0.92.

[0058] In some embodiments, the ratio of the polyol to the isocyanate satisfies an isocyanate index (NCO / OH ratio) of 2-2.8. In exemplary embodiments, the isocyanate index may be 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, or any range between the isocyanate indices. The polyurethane film obtained within the isocyanate index range has a soft hardness and is easily bonded to the silicone layer.

[0059] In some embodiments, the amount of the end-capping agent is 0.5-1.5% of the sum of the mass of isocyanate, polyol, hydrophilic chain extender, small molecule chain extender, neutralizer and post-chain extender. In exemplary embodiments, it can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.2%, 1.3%, 1.4%, 1.5%, etc., which are typical but non-limiting mass percentages, or a range between any two mass percentages. In this case, the obtained double-bond end-capped waterborne polyurethane can fully react with the two-component silicone without affecting the curing and molding of the silicone.

[0060] In some embodiments, the catalyst is an organobismuth catalyst, preferably at least one of BCAT-E28A and BCAT-E16.

[0061] In some embodiments, the diluent is acetone and / or butanone.

[0062] The second aspect of the present application provides a method for preparing a waterborne polyurethane and silicone composite bionic material, comprising the following steps: S1, spraying the double-bond terminated waterborne polyurethane into a polytetrafluoroethylene mold, heating and drying to obtain a polyurethane layer; S2, spraying a platinum catalyst onto the surface of the polyurethane layer, then evenly mixing component A and component B of the two-component silicone, pouring them into a polytetrafluoroethylene mold, oscillating and flattening them, and curing and molding them to obtain the waterborne polyurethane and silicone composite bionic material.

[0063] In some embodiments, the heating temperature in step S1 is 80-120° C., the heating time is 3-10 min, and the thickness of the polyurethane layer is 0.1-0.3 mm.

[0064] In some embodiments, the spraying amount of platinum catalyst in step S2 is 12-20 g / m 2 In the example, it can be 12g / m 2 , 13g / m 2 , 14g / m 2 , 15g / m 2 , 16g / m 2 , 17g / m 2 , 18g / m 2 , 19g / m 2 , 20g / m 2 Typical but non-limiting spray amounts such as or any range between spray amounts, in which case the polyurethane layer is fully bonded to the two-component silicone and the polyurethane layer is in good condition.

[0065] In some embodiments, the platinum catalyst is at least one of a Speier catalyst, a Karstedt's catalyst and an Ashby's catalyst. Preferably, the platinum catalyst is a KP25 catalyst of Shanghai Neutron Star Chemical Technology Co., Ltd.

[0066] In some embodiments, the amount of two-component silica gel used in step S2 is 15-18 kg / m 2 .

[0067] In some embodiments, the curing molding temperature in step S2 is 20-30°C. In the exemplary embodiment, it can be a typical but non-restrictive temperature such as 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, or a range between any two temperatures. Within this temperature range, the reaction rate between the polyurethane layer and the two-component silicone is moderate, and the quality of the obtained bionic material is better.

[0068] The third aspect of the present application provides the application of the above-mentioned water-based polyurethane and silicone composite bionic material in artificial skin, soft robots, wearable devices and prosthetic epidermis.

[0069] The technical solution of the present application is illustrated below through specific embodiments and comparative examples.

[0070] Example 1 A method for preparing a waterborne polyurethane and silica gel composite bionic material, wherein the isocyanate index of polyol and isocyanate in the double-bond terminated waterborne polyurethane preparation process is 2.5, and the method comprises the following steps: (1) 120 g of polytetrahydrofuran polyol (molecular weight 3000) and 22.2 g of isophorone diisocyanate were added to a flask, stirred and reacted at 90° C. for 2 h, then 4.27 g of dihydroxymethyl propionic acid, 0.74 g of 1,4-butanediol and 15 g of acetone were added, stirred and reacted at 80° C. for 2 h, then 0.28 g of organic bismuth catalyst BCAT-E28A and 10 g of acetone were added, the temperature was lowered to 70° C. and the reaction was continued for 3 h, 1.47 g of hydroxyethyl methacrylate was added, and the temperature was kept for reaction for 1 h to obtain a prepolymer, the prepolymer was cooled to 50° C., 110 g of acetone and 3.22 g of triethylamine were added, and the reaction was carried out for 5 min, then the temperature was lowered to 10° C., 279 g of deionized water was added, the speed was 2000 r / m, and the stirring and dispersion was carried out for 10 min, and then 0.92 g of ethylenediamine was added and stirred for reaction for 30 min, and the acetone was removed to obtain the double-bond terminated waterborne polyurethane; (2) spraying the double-bond terminated waterborne polyurethane into a polytetrafluoroethylene mold and heating it at 80°C for 10 min to obtain a polyurethane layer with a thickness of 0.1 mm; (3) Spray the KP25 catalyst produced by Shanghai Neutron Star Chemical Technology Co., Ltd. onto the surface of the polyurethane layer. The spraying amount of KP25 catalyst is 16g / m 2 Then mix the A and B components of the two-component silicone and pour them into the polytetrafluoroethylene mold, shake and flatten them. The amount of two-component silicone is 20kg / m 2 , and cured at 25° C. for 10 hours to obtain the waterborne polyurethane and silica gel composite bionic material.

[0071] The two-component silicone is an addition-type AB two-component platinum silicone with model number MCD800013A produced by Foshan Mingchen Silicone Co., Ltd., including component A and component B, and the mass ratio of component A to component B is 1:1.

[0072] Example 2 A method for preparing a waterborne polyurethane and silica gel composite bionic material, wherein the isocyanate index of polyol and isocyanate in the double-bond terminated waterborne polyurethane preparation process is 2.0, and the method comprises the following steps: (1) 150 g of polytetrahydrofuran polyol (molecular weight 3000) and 22.2 g of isophorone diisocyanate were added to a flask, stirred and reacted at 85° C. for 2 h, then 4.84 g of dihydroxymethyl propionic acid, 0.74 g of 1,4-butanediol and 15 g of acetone were added, stirred and reacted at 70° C. for 3 h, then 0.30 g of organic bismuth catalyst BCAT-E28A and 10 g of acetone were added, the temperature was lowered to 65° C. and the reaction was continued for 5 h, 1.47 g of hydroxyethyl methacrylate was added, and the temperature was kept for reaction for 1 h to obtain a prepolymer, the prepolymer was cooled to 40° C., 110 g of acetone and 3.22 g of triethylamine were added, and the reaction was carried out for 3 min, then the temperature was lowered to 10° C., 279 g of deionized water was added, the speed was 3000 r / m, and the stirring and dispersion was carried out for 15 min, and then 0.92 g of ethylenediamine was added and stirred for reaction for 30 min, and the acetone was removed to obtain the double-bond terminated waterborne polyurethane; (2) spraying the double-bond terminated waterborne polyurethane into a polytetrafluoroethylene mold and heating it at 100°C for 5 minutes to obtain a polyurethane layer with a thickness of 0.2 mm; (3) Spray the KP25 catalyst produced by Shanghai Neutron Star Chemical Technology Co., Ltd. onto the surface of the polyurethane layer. The spraying amount of KP25 catalyst is 16g / m 2 Then mix the A and B components of the two-component silicone and pour them into the polytetrafluoroethylene mold, shake and flatten them. The amount of two-component silicone is 20kg / m 2 , and cured at 25° C. for 10 hours to obtain the waterborne polyurethane and silica gel composite bionic material.

[0073] The composition of the two-component silica gel is the same as that of Example 1.

[0074] Example 3 A method for preparing a waterborne polyurethane and silica gel composite bionic material, wherein the isocyanate index of polyol and isocyanate in the double-bond terminated waterborne polyurethane preparation process is 2.8, and the method comprises the following steps: (1) 159.2 g of polytetrahydrofuran polyol (molecular weight 3000) and 33 g of isophorone diisocyanate were added to a flask, stirred and reacted at 95° C. for 3 h, then 5.9 g of dihydroxymethyl propionic acid, 0.74 g of 1,4-butanediol and 15 g of acetone were added, stirred and reacted at 85° C. for 2 h, then 3.5 g of organic bismuth catalyst BCAT-E28A and 10 g of acetone were added, the temperature was lowered to 75° C. and the reaction was continued for 3 h, 1.47 g of hydroxyethyl methacrylate was added, and the temperature was kept for reaction for 1 h to obtain a prepolymer, the prepolymer was cooled to 50° C., 110 g of acetone and 3.22 g of triethylamine were added, and the reaction was carried out for 5 min, then the temperature was lowered to 15° C., 350 g of deionized water was added, the speed was 3500 r / m, and the mixture was stirred and dispersed for 20 min, and then 0.92 g of ethylenediamine was added and stirred for reaction for 30 min, and acetone was removed to obtain the double-bond terminated waterborne polyurethane; (2) spraying the double-bond terminated waterborne polyurethane into a polytetrafluoroethylene mold and heating it at 120°C for 3 minutes to obtain a polyurethane layer with a thickness of 0.3 mm; (3) Spray the KP25 catalyst produced by Shanghai Neutron Star Chemical Technology Co., Ltd. onto the surface of the polyurethane layer. The spraying amount of KP25 catalyst is 16g / m 2 Then mix the A and B components of the two-component silicone and pour them into the polytetrafluoroethylene mold, shake and flatten them. The amount of two-component silicone is 20kg / m 2 , and cured at 20° C. for 10 h to obtain the waterborne polyurethane and silica gel composite bionic material.

[0075] The composition of the two-component silica gel is the same as that of Example 1.

[0076] Example 4 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 1, the only difference is that the amount of hydroxyethyl methacrylate in Example 1 is adjusted from "1.47g" to "0.76g".

[0077] Example 5 A method for preparing a waterborne polyurethane and silicone composite biomimetic material, compared with Example 1, the only difference is that the amount of hydroxyethyl methacrylate in Example 1 is adjusted from "1.47g" to "2.27g".

[0078] Example 6 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 1, the only difference is that the amount of platinum catalyst in Example 1 is changed from "the amount of platinum catalyst sprayed is 16g / m 2 "Adjusted to" Platinum catalyst spraying amount is 12g / m 2 ”.

[0079] Example 7 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 1, the only difference is that the amount of platinum catalyst in Example 1 is changed from "the amount of platinum catalyst sprayed is 16g / m 2 "Adjusted to" Platinum catalyst spraying amount is 20g / m 2 ”.

[0080] Example 8 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 1, the only difference is that the amount of platinum catalyst in step (3) of Example 1 is adjusted from "curing at 25°C for 10 hours" to "curing at 30°C for 10 hours".

[0081] Comparative Example 1 A method for preparing a waterborne polyurethane and silicone composite biomimetic material, compared with Example 1, the only difference is that the hydroxyethyl methacrylate in step (1) of Example 1 and the KP25 catalyst in step (3) are removed.

[0082] Comparative Example 2 A method for preparing a waterborne polyurethane and silicone composite biomimetic material, compared with Example 1, the only difference is that the hydroxyethyl methacrylate in step (1) of Example 1 is removed.

[0083] Comparative Example 3 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 1, the only difference is that the KP25 catalyst in step (3) of Example 1 is removed.

[0084] Comparative Example 4 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 1, the only difference is that the isocyanate index of the polyol and isocyanate in the preparation process of the double-bond terminated waterborne polyurethane is 3.5, that is, the amount of isophorone diisocyanate in Example 1 is adjusted from "22.2g" to "31.08g".

[0085] Comparative Example 5 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 6, the only difference is that the amount of platinum catalyst in Example 6 is changed from "the amount of platinum catalyst sprayed is 12g / m 2 "Adjusted to" Platinum catalyst spraying amount is 10g / m 2 ”.

[0086] Comparative Example 6 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 7, the only difference is that the amount of platinum catalyst in Example 7 is changed from "the amount of platinum catalyst sprayed is 20g / m 2 "Adjusted to" Platinum catalyst spraying amount is 22g / m 2 ”.

[0087] Comparative Example 7 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 3, the only difference is that the amount of platinum catalyst in step (3) of Example 3 is adjusted from "curing at 20°C for 10 hours" to "curing at 15°C for 10 hours".

[0088] Comparative Example 8 A method for preparing a waterborne polyurethane and silicone composite bionic material, compared with Example 8, the only difference is that the amount of platinum catalyst in step (3) of Example 8 is adjusted from "curing at 30°C for 10 hours" to "curing at 35°C for 10 hours".

[0089] The peel strength test of the waterborne polyurethane and silicone composite bionic materials obtained in Examples 1 to 8 and Comparative Examples 1 to 8 was carried out according to the test reference standard GB / T8808-1988 "Peeling test method for soft composite plastic materials". The test results are shown in Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown in Table 1; Table 1

[0090] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As can be seen from the test results in Table 1, compared with Comparative Examples 1 to 8, the waterborne polyurethane and silicone composite biomimetic materials prepared in Examples 1 to 8 have higher peel strengths, and the specific analysis is as follows: Comparative Examples 1 and 2 show that conventional waterborne polyurethane (without end-capping treatment) has almost no bonding with silicone, that is, whether the conventional waterborne polyurethane is sprayed with platinum catalyst or not, it can hardly bond with silicone; Comparative Example 3 is a bonding test of end-capped double-bond waterborne polyurethane with silicone, and the results show that when the platinum catalyst is not sprayed, the bonding performance of the end-capped double-bond waterborne polyurethane with silicone is also poor; It can be seen from the test results of Example 1 and Comparative Example 4 that, due to the hardness of the waterborne polyurethane design, its bonding performance with silica gel is average even under the catalytic action of an equal amount of platinum catalyst on the surface; It can be seen from the test results of Example 6 and Comparative Example 5 that the waterborne polyurethane cannot be combined with the silica gel because the amount of platinum catalyst used in Comparative Example 5 is too small; It can be seen from the test results of Example 7 and Comparative Example 6 that in Comparative Example 6, the amount of platinum catalyst used was too much, and the water-based polyurethane reacted too violently with the silica gel, resulting in too much heat accumulation on the surface of the polyurethane and damage to the film-forming resin. Not only was the surface of the molded skin damaged by excessive heat accumulation, resulting in black damage, but also its peel strength was reduced; It can be seen from the test results of Example 3 and Comparative Example 7 that the curing temperature of the silicone in Comparative Example 7 is 15°C. Too low a temperature can easily lead to too slow a polymerization rate, thereby affecting the reaction molding of the double-bond polyurethane and the silicone, resulting in low peel strength of the two combinations; It can be seen from the test results of Example 8 and Comparative Example 8 that the curing temperature of the silicone in Comparative Example 8 is 35°C. If the temperature is too high, the silicone body will react too quickly, and the silicone and double-bond polyurethane will not react easily, resulting in low peel strength of the two combinations. Since Examples 1 to 8 are tests for the combination of end-capped double-bond waterborne polyurethane and silicone, the waterborne polyurethane is designed to be soft, and the platinum catalyst on the film-forming surface promotes the reaction between the double-bond waterborne polyurethane and silicone, so its peeling strength is high, and its peeling is the peeling strength that destroys the substrate, because the tear strength of silicone is only 5N, so the data can only be tested to reach 5N / 3cm, because the bottom silicone has been torn, so the chain segment is relatively soft. Waterborne polyurethane and platinum catalyst sprayed on the film-forming surface are two key technologies for firmly compounding end-capped double-bond waterborne polyurethane and silicone. Since a thin layer of waterborne polyurethane coating is compounded on the surface of silicone, it not only changes the shortcomings of silicone that it is easy to penetrate oil and has a poor touch, but also can be high on the surface of waterborne polyurethane, and its surface can be subjected to many surface treatments, so that a variety of silicone composite materials with different hand feelings and functions can be obtained, and in addition, the material has a touch that is very close to the skin.

[0091] The waterborne polyurethane and silicone composite bionic materials obtained in Examples 1 to 8 were subjected to room temperature folding resistance, low temperature folding resistance, odor test and Martindale abrasion resistance test according to relevant standards, and the results are shown in Table 2: Table 2

[0092] As can be seen from Table 2, the waterborne polyurethane and silicone composite bionic materials obtained in Examples 1 to 8 have room temperature folding resistance, low temperature folding resistance and Martindale abrasion resistance test results, indicating that they fully meet the qualified standards for use. Therefore, they have broad application prospects in artificial skin, soft robots, wearable devices and prosthetic epidermis.

[0093] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0094] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waterborne polyurethane and silicone composite bionic material, characterized in that: It comprises a silicone layer and a polyurethane layer, wherein the material of the silicone layer comprises two-component silicone, the material of the polyurethane layer comprises double-bond terminated waterborne polyurethane, and the silicone layer and the polyurethane layer are bonded together through chemical reaction under the action of a platinum catalyst.

2. The waterborne polyurethane and silicone composite bionic material according to claim 1, characterized in that: The raw materials of the double-bond terminated waterborne polyurethane include isocyanate, polyol, hydrophilic chain extender, small molecule chain extender, end-capping agent, neutralizing agent and post-chain extender.

3. The waterborne polyurethane and silicone composite bionic material according to claim 1, characterized in that: The two-component silicone is an addition-type AB two-component platinum silicone.

4. The waterborne polyurethane and silicone composite bionic material according to claim 2, characterized in that: The end-capping agent is at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate and hydroxyethyl acrylate.

5. The waterborne polyurethane and silicone composite bionic material according to claim 2, characterized in that: The ratio of the polyol to the isocyanate satisfies an isocyanate index of 2-2.

8.

6. The waterborne polyurethane and silicone composite bionic material according to claim 2, characterized in that: The amount of the end-capping agent is 0.5-1.5% of the total mass of the isocyanate, the polyol, the hydrophilic chain extender, the small molecule chain extender, the neutralizer and the post-chain extender.

7. The method for preparing a waterborne polyurethane and silicone composite bionic material according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, spraying the double-bond terminated waterborne polyurethane into the mold, heating and drying to obtain a polyurethane layer; S2, spraying a platinum catalyst onto the surface of the polyurethane layer, then evenly mixing component A and component B of the two-component silicone, pouring them into a mold, oscillating and flattening them, and curing and forming them to obtain the waterborne polyurethane and silicone composite bionic material.

8. The method for preparing a waterborne polyurethane and silicone composite bionic material according to claim 7, characterized in that: The spraying amount of platinum catalyst in step S2 is 12-20g / m 2 , the platinum catalyst is at least one of a Speier catalyst, a Karstedt's catalyst and an Ashby's catalyst.

9. The method for preparing a waterborne polyurethane and silicone composite bionic material according to claim 7, characterized in that: The curing temperature in step S2 is 20-30°C.

10. Use of a waterborne polyurethane and silicone composite bionic material according to any one of claims 1 to 6, characterized in that: The waterborne polyurethane and silicone composite bionic material is used in artificial skin, soft robots, wearable devices and prosthetic epidermis.

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