Waterborne polyurethane with amide alkyl ester structural unit and preparation method thereof

Abstract

The invention belongs to the technical field of polymer materials, and particularly discloses waterborne polyurethane with an amide alkyl ester structural unit and a preparation method of the waterborne polyurethane. The main chain of the waterborne polyurethane is provided with an amide alkyl ester structural unit, and different from the traditional polyurethane obtained through polyamide polyol reaction, an ester bond with a longer alkyl carbon chain is closely connected with an amido bond in the main chain of the introduced polymer polyol with the amido bond; therefore, the prepared polyurethane not only has higher mechanical strength in the final performance, but also can obtain excellent flexibility, and is better in hydrolysis resistance. When the waterborne polyurethane is used as a glass fiber impregnating compound to be applied to glass fiber reinforced nylon plastics, the mechanical strength of resin can be greatly improved under the condition of keeping the original performance requirements, and meanwhile, the bonding strength of the glass fiber impregnating compound to a nylon matrix needing to be reinforced is improved; and the overall performance of the composite material is enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to a waterborne polyurethane having an amide alkyl ester structural unit and a preparation method thereof. Background Art

[0002] Polyurethane is a polymer material with excellent mechanical properties formed by polyols and polyisocyanates through condensation reaction. It has good physical and chemical properties and excellent flexibility. Waterborne polyurethane resin is a uniform emulsion formed by dispersing polyurethane in water. It has the advantages of non-flammability, low odor, no environmental pollution, energy saving, convenient operation and processing, and is widely used as an adhesive and coating. However, waterborne polyurethane resin generally has technical problems such as poor hydrolysis resistance under acid and alkali conditions, low mechanical strength and poor heat resistance. Polyamide is a thermoplastic resin containing repeated amide groups on the main chain of the molecule. It has excellent mechanical strength and heat resistance, but poor flexibility. Therefore, polyamide is often used in the prior art to modify waterborne polyurethane to improve the mechanical strength and water resistance and heat resistance of waterborne polyurethane.

[0003] At present, it is very difficult to improve the tensile strength of polyurethane while maintaining good flexibility when modifying waterborne polyurethane with polyamide. Most polyamide-modified polyurethane materials are still difficult to water-based and cannot have both flexibility and strength. In many application fields, especially in the field of waterborne polyurethane for reinforced glass fiber sizing, the sizing is required to play a certain role in promoting the reinforcement of composite materials. Therefore, the strength and toughness requirements of waterborne polyurethane are relatively high.

[0004] Therefore, there is an urgent need to develop a waterborne polyurethane that can simultaneously possess good mechanical strength, flexibility and hydrolysis resistance. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a waterborne polyurethane having an amide alkyl ester structural unit and a preparation method thereof, wherein the waterborne polyurethane has high mechanical strength, flexibility and hydrolysis resistance, and has a good reinforcing effect on glass fiber nylon plastic.

[0006] The inventive concept of the present invention is that the main chain of the waterborne polyurethane of the present invention has an amide alkyl ester structural unit, which is different from the polyurethane obtained by the traditional reaction of polyamide polyols. The main chain of the polymer polyol with an amide bond introduced in the present invention is closely connected to the amide bond by an ester bond with a longer alkyl carbon chain, so that the prepared polyurethane has both high mechanical strength and excellent flexibility in the final performance. And by adjusting the mass content of the amide group in the polymer polyol and the distribution uniformity on the main chain of the polymer polyol, the mechanical strength and flexibility of the polyurethane can be adjusted arbitrarily. At the same time, compared with traditional polyurethanes, the waterborne polyurethane of the present invention has better hydrolysis resistance, so that it has a wide range of application prospects in occasions with high performance requirements for hydrolysis resistance. The waterborne polyurethane of the present invention is used as a glass fiber sizing agent in glass fiber reinforced nylon plastics, which can greatly improve the mechanical strength of the resin while maintaining the original performance requirements (such as flexibility), and at the same time improve the bonding strength of the glass fiber sizing agent to the nylon matrix to be strengthened, so that the overall performance of the composite material is enhanced.

[0007] In order to solve the above technical problems, the first aspect of the present invention provides an aqueous polyurethane, wherein the aqueous polyurethane is obtained by reacting a polyol and an isocyanate compound, wherein the polyol comprises a first polyol and a second polyol, wherein the chemical structure of the first polyol is as shown in formula (1), and the second polyol is a hydrophilic polyol;

[0008]

[0009] Where: s is 2, 3 or 4, t is 2, 3 or 4, m>1, n>1;

[0010] R1 is selected from substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl, C2-C6 alkyl or polyether structure, and the substitution refers to substitution with alkyl.

[0011] Preferably, the R1 is selected from one of the following structural formulas:

[0012]

[0013] Preferably, the second polyol is at least one selected from polyethylene glycol, linear bifunctional polyethylene glycol monomethyl ether, dimethylol propionic acid, dimethylol butyric acid, and N-methyldiethanolamine.

[0014] Preferably, the linear bifunctional polyethylene glycol monomethyl ether is selected from Pasto Ymer TM N120, Pasto Ymer TM N90, Pasto Ymer TM At least one of N180.

[0015] Preferably, the molecular weight of the polyethylene glycol is 400-4000.

[0016] Preferably, the isocyanate compound is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate trimer.

[0017] Preferably, in the first polyol, the mass content of amide groups is ≥2%; further preferably, the mass content of amide groups is 2-20%; further preferably, the mass content of amide groups is 4-19%.

[0018] Preferably, in the polyol, the mass proportion of the first polyol is ≥5%; further preferably, the mass proportion of the first polyol is 5-98%; further preferably, the mass proportion of the first polyol is 6-94%.

[0019] Preferably, in the polyol, the mass proportion of the second polyol is 2-40%.

[0020] Preferably, the molar ratio of the total molar number of hydroxyl groups in the polyol to the isocyanate groups in the isocyanate compound is 1:(1.1-2.5).

[0021] Preferably, the polyol further comprises a third polyol, the third polyol is selected from at least one of ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, ethyl butyl propane glycol, 1,4-cyclohexanedimethanol, trimethylolpropane, and a polyol, and the polyol is selected from at least one of polyester polyols, polyether polyols, polytetramethylene glycol, polycaprolactone polyols, and polycarbonate polyols.

[0022] Preferably, the molecular weight of the polyol is 300-3000.

[0023] Preferably, in the polyol, the mass of the third polyol accounts for 0-95%.

[0024] The second aspect of the present invention provides a method for preparing the above-mentioned waterborne polyurethane, comprising the following steps:

[0025] (1) under the action of a catalyst, adding a cyclic lactone dropwise to a polyamine containing a first solvent to carry out a ring-opening reaction to obtain a first polyol having an amide alkyl ester structural unit;

[0026] (2) adding the first polyol, the second polyol and the isocyanate compound into a second solvent to carry out a polycondensation reaction to obtain a prepolymer;

[0027] (3) After neutralizing the prepolymer, dispersing it in water, adding a chain extender to react, and obtaining the waterborne polyurethane.

[0028] Preferably, in step (1), the cyclic lactone is selected from at least one of butyrolactone, valerolactone and caprolactone.

[0029] Preferably, in step (1), the polyamine is selected from at least one of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, isophoronediamine, p-phenylenediamine, m-phenylenediamine and polyetheramine.

[0030] Preferably, in step (1), the catalyst is selected from at least one of n-butyltin oxide, dibutyltin oxide, stannous octoate, dibutyltin dilaurate, n-butyl titanate, and tetraisopropyl titanate.

[0031] Preferably, in step (1), the first solvent is selected from at least one of N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and N,N-dimethylpropionamide.

[0032] Preferably, in step (1), the molar ratio of the polyamine to the cyclic lactone is 1:(4-20).

[0033] Preferably, in step (1), the mass proportion of the first solvent in the reaction system of step (1) is 0-80%.

[0034] Preferably, in step (1), the ring-opening reaction is carried out at 40-120° C. for 2-7 hours.

[0035] Preferably, in step (1), the dripping time is 1-4 hours.

[0036] Preferably, in step (2), the second solvent is selected from at least one of N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, acetone and butanone.

[0037] Preferably, in step (2), the mass proportion of the second solvent in the reaction system of step (2) is 0-30%.

[0038] Preferably, in step (2), the polycondensation reaction is carried out at 60-100° C. for 2-12 hours.

[0039] Preferably, in step (3), the neutralization adopts an acid or a base, the acid is selected from at least one of formic acid, acetic acid, lactic acid, and methanesulfonic acid, and the base is selected from at least one of triethylamine and N,N-dimethylcyclohexylamine.

[0040] Preferably, in step (3), the chain extender is selected from at least one of hydrazine hydrate, ethylenediamine, 1,6-hexanediamine, isophoronediamine, p-phenylenediamine, m-phenylenediamine, aminosulfonate chain extender, silane coupling agent, and deionized water.

[0041] Preferably, the aminosulfonate chain extender is selected from Evonik VESTAMIN A95.

[0042] Preferably, the silane coupling agent is selected from KH550.

[0043] The third aspect of the present invention provides a wetting agent, which comprises the above-mentioned water-based polyurethane.

[0044] When the waterborne polyurethane of the present invention acts as a wetting agent on glass fiber reinforced nylon plastic, while maintaining the basic properties of the resin (such as flexibility), the mechanical strength and the bonding strength of the nylon matrix resin can be greatly improved, thereby enhancing the overall performance of the material.

[0045] Compared with the prior art, the above technical solution of the present invention has at least the following technical effects or advantages:

[0046] (1) The main chain of the waterborne polyurethane of the present invention has an amide alkyl ester structural unit. By introducing an ester bond with a longer alkyl carbon chain closely connected to the amide bond into the main chain of the polymer polyol having an amide bond, the prepared waterborne polyurethane has good mechanical strength and flexibility, achieving a tensile strength of 16.2-47.8 MPa and an elongation at break of 175-642%.

[0047] (2) Compared with traditional polyurethanes, the waterborne polyurethane with amidoalkyl ester structural units in the main chain of the present invention has better hydrolysis resistance, which can reach 57.3-86.3%, so that it has a wide application prospect in occasions with high performance requirements for hydrolysis resistance.

[0048] (3) The waterborne polyurethane of the present invention can adjust the mass content of the amide groups in the polymer polyol and the distribution uniformity of the amide groups on the main chain of the polymer polyol, thereby achieving arbitrary adjustment of the mechanical strength and flexibility of the waterborne polyurethane to meet different application requirements.

[0049] (4) The aqueous polyurethane of the present invention is used as a sizing agent in glass fiber reinforced nylon plastics, which can improve the mechanical strength of the resin while maintaining the original performance requirements (such as flexibility), and at the same time improve the bonding strength of the glass fiber sizing agent to the nylon matrix to be reinforced, the peel strength can reach 0.466-2.617MPa, and the overall performance of the composite material is enhanced. The glass fiber reinforced nylon plastic is applied to the automotive field, which is conducive to achieving lightweight automobiles. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the infrared spectrum of the first polyol EDACL0104 prepared in Example 1. DETAILED DESCRIPTION

[0051] The present invention is described in detail below in conjunction with the examples, so that the technical personnel of the relevant technical field can understand the present invention. It is necessary to point out here that the examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. The non-essential improvements and adjustments made to the present invention by the skilled person in the relevant field according to the above invention content should still belong to the scope of protection of the present invention. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods that are not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0052] Example 1

[0053] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0054] 30 g of ethylenediamine, 60 g of N,N-dimethylacetamide, and 0.025 g of dibutyltin dilaurate were added to a 500 mL four-necked flask, and nitrogen was introduced. The flask was heated to 80° C. At this temperature, 230 g of caprolactone (Perstorp) was added dropwise (the reaction will automatically release heat, and the reaction temperature is maintained at <95° C.) for 1 hour. After the addition was completed, the flask was kept at 90° C. for 2 hours, and then the material was filtered at this temperature to obtain a first polyol having an amide alkyl ester structural unit, which was recorded as EDACL-0104.

[0055] Figure 1 This is the infrared spectrum of the first polyol EDACL0104 prepared in Example 1. From the spectrum, it can be clearly seen that the ester bond (1729 cm -1 ) and amide bonds (1635 cm -1 and 1557cm -1 )’s characteristic absorption peak.

[0056] Example 2

[0057] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0058] 15 g of ethylenediamine, 55 g of N,N-dimethylacetamide, and 0.025 g of dibutyltin dilaurate were added to a 500 mL four-necked flask, and nitrogen was introduced. The flask was heated to 80° C. At this temperature, 230 g of caprolactone (Perstorp) was added dropwise (the reaction would automatically release heat, and the reaction temperature was maintained at <95° C.) for 1 hour. After the addition was completed, the flask was kept at 90° C. for 2 hours, and then the material was filtered at this temperature to obtain a first polyol having an amide alkyl ester structural unit, which was recorded as EDACL-0108.

[0059] Example 3

[0060] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0061] 7.5 g of ethylenediamine, 50 g of N,N-dimethylacetamide, and 0.025 g of dibutyltin dilaurate were added to a 500 mL four-necked flask, and nitrogen was introduced. The flask was heated to 80° C. At this temperature, 230 g of caprolactone (Perstorp) was added dropwise (the reaction will automatically release heat, and the reaction temperature is maintained at <95° C.) for 1 hour. After the addition is completed, the flask is kept at 90° C. for 2 hours, and then the material is filtered at this temperature to obtain a first polyol having an amide alkyl ester structural unit, which is recorded as EDACL-0116.

[0062] Example 4

[0063] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0064] 15 g of ethylenediamine, 44 g of N,N-dimethylacetamide, and 0.025 g of dibutyltin dilaurate were added to a 500 mL four-necked flask, and nitrogen was introduced. The flask was heated to 80°C, and 173 g of butyrolactone (Maiqi Chemical) was added dropwise at this temperature (the reaction will automatically release heat, and the reaction temperature is maintained at <95°C). The reaction was continued for 1 hour. After the addition was completed, the flask was kept at 90°C for 2 hours, and then the material was filtered at this temperature to obtain the first polyol having an amide alkyl ester structural unit, which was recorded as EDABL-0108.

[0065] Example 5

[0066] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0067] 15 g of ethylenediamine, 44 g of N,N-dimethylacetamide, and 0.025 g of dibutyltin dilaurate were added to a 500 mL four-necked flask, and nitrogen was introduced. The flask was heated to 80°C, and 259 g of butyrolactone (Maiqi Chemical) was added dropwise at this temperature (the reaction will automatically release heat, and the reaction temperature is maintained at <95°C). The reaction was continued for 1 hour. After the addition was completed, the flask was kept at 90°C for 2 hours, and then the material was filtered at this temperature to obtain the first polyol having an amide alkyl ester structural unit, which was recorded as EDABL-0112.

[0068] Example 6

[0069] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0070] 58.2 g of 1,6-hexanediamine, 55 g of N,N-dimethylacetamide, and 0.025 g of dibutyltin dilaurate were added to a 500 mL four-necked flask, and nitrogen was introduced. The flask was heated to 80°C, and 173 g of butyrolactone (Maiqi Chemical) was added dropwise at this temperature (the reaction will automatically release heat, and the reaction temperature is maintained at <95°C). The addition was continued for 1 hour. After the addition was completed, the flask was kept at 90°C for 2 hours, and then the material was filtered at this temperature to obtain the first polyol having an amide alkyl ester structural unit, which was recorded as HDABL-0104.

[0071] Example 7

[0072] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0073] 29.1 g of 1,6-hexanediamine, 47 g of N,N-dimethylacetamide, and 0.025 g of dibutyltin dilaurate were added to a 500 mL four-necked flask, and nitrogen was introduced. The flask was heated to 80°C, and 173 g of butyrolactone (Maiqi Chemical) was added dropwise at this temperature (the reaction will automatically release heat, and the reaction temperature is maintained at <95°C). The reaction was continued for 1 hour. After the addition was completed, the flask was kept at 90°C for 2 hours, and then the material was filtered at this temperature to obtain the first polyol having an amide alkyl ester structural unit, which was recorded as HDABL-0108.

[0074] Example 8

[0075] A preparation method of a first polyol having an amide alkyl ester structural unit comprises the following steps:

[0076] Will EC 301, 70g N,N-dimethylacetamide, and 0.025g dibutyltin dilaurate were added to a 500mL four-necked flask, and nitrogen was introduced. The flask was heated to 85°C, and 173g of butyrolactone (Maiqi Chemical) was added dropwise at this temperature (the reaction will automatically release heat, and the reaction temperature is maintained at <105°C). The addition was continued for 1 hour. After the addition was completed, the flask was kept at 95°C for 2 hours, and then the material was filtered at this temperature to obtain the first polyol having an amide alkyl ester structural unit, which was recorded as POABL-0104.

[0077] Example 9

[0078] A method for preparing waterborne polyurethane comprises the following steps:

[0079] 40.9g DP-3000M (Guodu, Mn=3000), 75.5g DP-1000M (Guodu, Mn=1000), 10.7g EDACL-0104 were added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 10.0g dimethylolpropionic acid (Perstorp), 10.0g N,N-dimethylpropionamide, and 81.4g isophorone diisocyanate (Wanhua) were added to the four-necked flask in turn, stirred evenly, reacted at 60°C for 30min, and then 0.03g of organic bismuth catalyst was added, heated to 90°C, reacted for 3h, tested NCO to near the theoretical value, lowered the temperature to 75°C, added 7.2g triethylamine, and stirred evenly. Add 364 g of deionized water, 3.8 g of Disponil A4070, and 1.6 g of Tego805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 8.1 g of hydrazine hydrate and 23.9 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 12.0 g of deionized water, stir well to obtain a semipermeable polyurethane (PUD) emulsion, recorded as PUD1.

[0080] Example 10

[0081] A method for preparing waterborne polyurethane comprises the following steps:

[0082] 39.6g DP-3000M (Guodu, Mn=3000), 73.1g DP-1000M (Guodu, Mn=1000), 20.7g EDACL-0104 were added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 9.7g dimethylolpropionic acid (Perstorp), 19.5g N,N-dimethylpropionamide, and 78.9g isophorone diisocyanate (Wanhua) were added to the four-necked flask in turn, stirred evenly, reacted at 60°C for 30min, added 0.03g of organic bismuth catalyst, heated to 90°C, reacted for 3h, tested NCO to near the theoretical value, lowered the temperature to 75°C, added 7.0g triethylamine, and stirred evenly. Add 353 g of deionized water, 3.7 g of Disponil A4070, and 1.5 g of Tego805N into a dispersion kettle, stir evenly and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 7.2 g of hydrazine hydrate and 23.2 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 11.8 g of deionized water, stir evenly to obtain a semipermeable PUD emulsion, recorded as PUD2.

[0083] Embodiment 11

[0084] A method for preparing waterborne polyurethane comprises the following steps:

[0085] 110.2g PE-9956 (Huafeng, Mn = 2000) and 20.8g EDACL-0104 were added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 9.8g dimethylolpropionic acid (Perstorp), 19.6g N,N-dimethylpropionamide, and 79.2g isophorone diisocyanate (Wanhua) were added to the four-necked flask in sequence, stirred evenly, reacted at 60°C for 30min, 0.03g of organic bismuth catalyst was added, heated to 90°C, reacted for 3h, NCO was tested to near the theoretical value, the temperature was lowered to 75°C, 7.0g triethylamine was added, and stirred evenly. Add 355 g of deionized water, 3.7 g of Disponil A4070, and 1.5 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 8.6 g of hydrazine hydrate and 23.2 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 11.8 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD3.

[0086] Example 12

[0087] A method for preparing waterborne polyurethane comprises the following steps:

[0088] 106.8g PE-9956 (Huafeng, Mn = 2000) and 40.3g EDACL-0108 were added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 9.5g dimethylolpropionic acid (Perstorp), 19.0g N,N-dimethylpropionamide, and 64.9g isophorone diisocyanate (Wanhua) were added to the four-necked flask in sequence, stirred evenly, reacted at 60°C for 30min, and then 0.03g of organic bismuth catalyst was added, heated to 90°C, reacted for 3h, tested NCO to near the theoretical value, lowered the temperature to 75°C, added 6.8g triethylamine, and stirred evenly. Add 356 g of deionized water, 3.6 g of Disponil A4070, and 1.5 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 6.0 g of hydrazine hydrate and 22.5 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 11.5 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD4.

[0089] Example 13

[0090] A method for preparing waterborne polyurethane comprises the following steps:

[0091] Add 179.1g EDACL-0116 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 9.8g dimethylolpropionic acid (Perstorp) and 59.3g isophorone diisocyanate (Wanhua) to the four-necked flask in sequence, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 75°C, add 7.1g triethylamine, and stir evenly. Add 345 g of deionized water, 3.7 g of Disponil A4070, and 1.6 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 5.5 g of hydrazine hydrate and 23.5 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 12.0 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD5.

[0092] Embodiment 14

[0093] A method for preparing waterborne polyurethane comprises the following steps:

[0094] 91.0g PE-9956 (Huafeng, Mn = 2000) and 48.7g EDABL-0108 were added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 10.3g dimethylolpropionic acid (Perstorp), 10.4g N,N-dimethylpropionamide, and 73.4g isophorone diisocyanate (Wanhua) were added to the four-necked flask in sequence, stirred evenly, reacted at 60°C for 30min, and then 0.03g of organic bismuth catalyst was added, heated to 90°C, reacted for 3h, tested NCO to near the theoretical value, lowered the temperature to 75°C, added 7.5g triethylamine, and stirred evenly. Add 357 g of deionized water, 3.9 g of Disponil A4070 and 1.6 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle for high-speed dispersion within 15 minutes, after dispersion for 10 minutes, add 6.8 g of hydrazine hydrate and 24.7 g of deionized water within 2-3 minutes, reduce the speed after addition and continue stirring for 30 minutes, then add 0.6 g of preservative BIT-20 and 12.5 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD6.

[0095] Embodiment 15

[0096] A method for preparing waterborne polyurethane comprises the following steps:

[0097] Add 48.4g PE-9956 (Huafeng, Mn=2000) and 103.3g EDABL-0112 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 10.3g dimethylolpropionic acid (Perstorp) and 74.3g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 75°C, add 7.4g triethylamine, and stir evenly. Add 355 g of deionized water, 3.9 g of DisponilA4070, and 1.6 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 6.8 g of hydrazine hydrate and 24.5 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 12.5 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD7.

[0098] Example 16

[0099] A method for preparing waterborne polyurethane comprises the following steps:

[0100] 94.8g PE-9956 (Huafeng, Mn = 2000) and 37.3g HDABL-0104 were added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 10.8g dimethylolpropionic acid (Perstorp), 20.3g N,N-dimethylpropionamide, and 80.5g isophorone diisocyanate (Wanhua) were added to the four-necked flask in sequence, stirred evenly, reacted at 60°C for 30min, and then 0.03g of organic bismuth catalyst was added, heated to 90°C, reacted for 3h, tested NCO to near the theoretical value, lowered the temperature to 75°C, added 7.8g triethylamine, and stirred evenly. Add 345 g of deionized water, 4.0 g of Disponil A4070 and 1.7 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 7.4 g of hydrazine hydrate and 25.7 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 13.1 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD8.

[0101] Embodiment 17

[0102] A method for preparing waterborne polyurethane comprises the following steps:

[0103] Add 65.1g PE-9956 (Huafeng, Mn=2000) and 78.1g HDABL-0108 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 10.4g dimethylolpropionic acid (Perstorp), 13.0g N,N-dimethylpropionamide, and 79.4g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 75°C, add 7.5g triethylamine, and stir evenly. Add 345 g of deionized water, 3.9 g of Disponil A4070 and 1.6 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle for high-speed dispersion within 15 minutes. After dispersion for 10 minutes, add 7.4 g of hydrazine hydrate and 24.7 g of deionized water within 2-3 minutes. After the addition, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 12.6 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD9.

[0104] Embodiment 18

[0105] A method for preparing waterborne polyurethane comprises the following steps:

[0106] Add 65.1g PH200 (Ube, Mn = 2000) and 78.1g HDABL-0108 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 10.4g dimethylolpropionic acid (Perstorp), 13.0g N,N-dimethylpropionamide, and 79.4g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g of organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 75°C, add 7.5g triethylamine, and stir evenly. Add 345 g of deionized water, 3.9 g of Disponil A4070 and 1.6 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle for high-speed dispersion within 15 minutes, after dispersion for 10 minutes, add 7.4 g of hydrazine hydrate and 24.7 g of deionized water within 2-3 minutes, reduce the speed after addition and continue stirring for 30 minutes, then add 0.6 g of preservative BIT-20 and 12.6 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD10.

[0107] Embodiment 19

[0108] A method for preparing waterborne polyurethane comprises the following steps:

[0109] Add 60.3g PH100 ​​(Ube, Mn = 1000) and 72.4g HDABL-0108 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 10.2g dimethylolpropionic acid (Perstorp), 30.0g N,N-dimethylpropionamide, and 87.4g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 75°C, add 7.3g triethylamine, and stir evenly. Add 334 g of deionized water, 3.6 g of Disponil A4070, and 1.5 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 8.0 g of hydrazine hydrate and 23.0 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 11.6 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD11.

[0110] Embodiment 20

[0111] A method for preparing waterborne polyurethane comprises the following steps:

[0112] Add 63.9g PH100 ​​(Ube, Mn = 1000) and 76.6g HDABL-0108 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C and add 10.8g dimethylolpropionic acid (Perstorp), 31.9g N,N-dimethylpropionamide, and 79.8g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g of organic bismuth catalyst, heat to 90°C, react for 4h, test NCO to near the theoretical value, lower the temperature to 75°C, add 7.7g triethylamine, and stir evenly. Add 334 g of deionized water, 3.8 g of Disponil A4070 and 1.6 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle for high-speed dispersion within 15 minutes, after dispersion for 10 minutes, add 6.0 g of hydrazine hydrate and 24.2 g of deionized water within 2-3 minutes, reduce the speed after addition and continue stirring for 30 minutes, then add 0.6 g of preservative BIT-20 and 12.4 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD12.

[0113] Embodiment 21

[0114] A method for preparing waterborne polyurethane comprises the following steps:

[0115] 59.7g PH100 ​​(Ube, Mn = 1000) and 71.7g HDABL-0108 were added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 10.1g dimethylolpropionic acid (Perstorp), 90.0g butanone, and 56.8g isophorone diisocyanate (Wanhua) were added to the four-necked flask in sequence, stirred evenly, reacted at 60°C for 30min, and then 0.03g of organic bismuth catalyst was added, heated to 75°C, reacted for 8h, tested NCO to near the theoretical value, lowered the temperature to 70°C, added 7.2g triethylamine, and stirred evenly. Add 307 g of deionized water, 3.6 g of Disponil A4070, and 1.5 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle for high-speed dispersion within 15 minutes, after dispersion for 10 minutes, add 2.5 g of ethylenediamine and 12 g of deionized water within 2-3 minutes, reduce the speed after addition and continue stirring for 30 minutes, then vacuum at 35-50°C to remove butanone, add 0.6 g of preservative BIT-20 and 22.6 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD13.

[0116] Embodiment 22

[0117] A method for preparing waterborne polyurethane comprises the following steps:

[0118] Add 136.5g HDABL-0108 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 10.5g dimethylolpropionic acid (Perstorp), 93.0g butanone, and 58.9g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 75°C, react for 8h, test NCO to near the theoretical value, lower the temperature to 70°C, add 7.5g triethylamine, and stir evenly. Add 295g of deionized water, 3.7g of Disponil A4070 and 1.6g of Tego805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle for high-speed dispersion within 15 minutes. After dispersion for 10 minutes, add 2.6g of ethylenediamine and 12g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then, vacuumize at 35-50°C to remove butanone, add 0.6g of preservative BIT-20 and 23.0g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD14.

[0119] Embodiment 23

[0120] A method for preparing waterborne polyurethane comprises the following steps:

[0121] Add 64.2g DP-1000M (Guodu, Mn=1000) and 57.0g POABL-0104 to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 11.4g dimethylolpropionic acid (Perstorp), 21.4g N,N-dimethylpropionamide, and 92.7g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 70°C, add 8.6g triethylamine, and stir evenly. Add 338g of deionized water, 4.3g of Disponil A4070 and 1.8g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 8.2g of hydrazine hydrate and 27.0g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6g of preservative BIT-20 and 13.8g of deionized water, stir well to obtain a semipermeable PUD emulsion, recorded as PUD15.

[0122] Comparative Example 1

[0123] A method for preparing waterborne polyurethane comprises the following steps:

[0124] Add 115.1g DP-1000M (Guodu, Mn=1000) to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 11.2g dimethylolpropionic acid (Perstorp), 23.0g N,N-dimethylpropionamide, 82.9g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 70°C, add 8.0g triethylamine, and stir evenly. Add 349 g of deionized water, 4.6 g of Disponil A4070, and 1.9 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 7.6 g of hydrazine hydrate and 29.0 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 14.8 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD16.

[0125] Comparative Example 2

[0126] A method for preparing waterborne polyurethane comprises the following steps:

[0127] Add 119.2g PH100 ​​(Ube, Mn = 1000) to a 500mL four-necked flask, heat to 105°C, dehydrate under vacuum for 1h, and then break the vacuum with dry nitrogen. Cool to below 70°C, add 11.2g dimethylolpropionic acid (Perstorp), 33.1g N,N-dimethylpropionamide, 85.4g isophorone diisocyanate (Wanhua) to the four-necked flask in turn, stir evenly, react at 60°C for 30min, add 0.03g organic bismuth catalyst, heat to 90°C, react for 3h, test NCO to near the theoretical value, lower the temperature to 75°C, add 8.0g triethylamine, and stir evenly. Add 340 g of deionized water, 4.0 g of Disponil A4070, and 1.6 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 7.9 g of hydrazine hydrate and 25.2 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 12.8 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD17.

[0128] Comparative Example 3

[0129] A method for preparing waterborne polyurethane comprises the following steps:

[0130] 117.4g PH100 ​​(Ube, Mn = 1000) was added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. Cooled to below 70°C, 11.0g dimethylolpropionic acid (Perstorp), 97.5g butanone, and 54.8g isophorone diisocyanate (Wanhua) were added to the four-necked flask in sequence, stirred evenly, reacted at 60°C for 30min, and then 0.03g of organic bismuth catalyst was added, heated to 75°C, reacted for 8h, tested NCO to near the theoretical value, lowered the temperature to 70°C, added 7.9g triethylamine, and stirred evenly. Add 310g of deionized water, 3.9g of DisponilA4070 and 1.6g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 2.5g of ethylenediamine and 12g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then, vacuumize at 35-50°C to remove butanone, add 0.6g of preservative BIT-20 and 23.0g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD18.

[0131] Comparative Example 4

[0132] A method for preparing waterborne polyurethane comprises the following steps:

[0133] 94.8g PE-9956 (Huafeng, Mn = 2000), 37.2g Capa TM2054 (Perstorp, polycaprolactone polyol, Mn = 550) was added to a 500mL four-necked flask, heated to 105°C, dehydrated under vacuum for 1h, and then the vacuum was broken with dry nitrogen. The temperature was lowered to below 70°C, and 10.8g of dimethylol propionic acid (Perstorp), 20.3g of N,N-dimethylpropionamide, and 80.5g of isophorone diisocyanate (Wanhua) were added to the four-necked flask in sequence. After stirring evenly, the mixture was reacted at 60°C for 30min, and 0.03g of an organic bismuth catalyst was added. The mixture was heated to 90°C and reacted for 3h. NCO was tested to near the theoretical value, the temperature was lowered to 75°C, and 7.8g of triethylamine was added and stirred evenly. Add 345 g of deionized water, 4.0 g of Disponil A4070 and 1.7 g of Tego 805N into a dispersion kettle, stir well and cool to 10°C, then quickly add the mixture in the four-necked flask into the dispersion kettle within 15 minutes and disperse at high speed. After dispersing for 10 minutes, add 7.4 g of hydrazine hydrate and 25.7 g of deionized water within 2-3 minutes. After adding, reduce the speed and continue stirring for 30 minutes. Then add 0.6 g of preservative BIT-20 and 13.1 g of deionized water, stir well to obtain a semi-permeable PUD emulsion, recorded as PUD19.

[0134] Performance Testing

[0135] 1. Structural characteristics

[0136] The mass proportion of the amide group in the first polyol having an amide alkyl ester structural unit prepared in Example 1-8 is shown in Table 1.

[0137] Table 1:

[0138]

[0139]

[0140] The structural characteristics of the waterborne polyurethanes synthesized in Examples 9-23 and Comparative Examples 1-4 are shown in Table 2, wherein: PPO refers to polypropylene glycol ether diol, with a molecular weight of about 1000, and the one used in the present invention is Guodu DP-1000M; PC refers to polycarbonate diol, with a molecular weight of about 1000, and the one used in the present invention is Ube PH100; PHA refers to polyhexamethylene adipate diol, with a molecular weight of about 2000, and the one used in the present invention is Huafeng PE-9956; the average distribution density of amide groups on the prepolymer molecular chain is defined as the ratio of the number of moles of amide groups in the prepolymer to the average number of moles of the prepolymer polymer; NA indicates that the test result does not exist.

[0141] Table 2:

[0142]

[0143]

[0144] 2. Physical properties

[0145] The tensile strength, elongation at break and hydrolysis resistance of the waterborne polyurethanes prepared in Examples 9-23 and Comparative Examples 1-4 were tested, and the waterborne polyurethanes were coated on the surface of a nylon plastic sheet. After complete drying, the peel strength between the waterborne polyurethane coating and the nylon plastic sheet was tested. The results are shown in Table 3.

[0146] The specific testing process is as follows:

[0147] (1) Tensile strength at break and elongation at break

[0148] A certain mass of waterborne polyurethane samples were weighed respectively, diluted with water to 20% solid content, poured into a polytetrafluoroethylene mold, and placed horizontally for 72 hours at room temperature (20-25°C) and humidity below 70%. When the paint film became transparent and free of bubbles, the entire polytetrafluoroethylene mold was placed horizontally in an 80°C oven and baked at a constant temperature for 12 hours. Six test specimens with the same width (5mm width of the narrow part), length of 100mm, and thickness in the range of 0.4-0.6mm were cut out with a standard cutter. Three of them were taken out for tensile testing according to the national standard GB / T 528-2009. The testing instrument was Hongtuo HT-140SC-020.

[0149] (2) Hydrolysis resistance

[0150] A portion of the waterborne polyurethane standard specimens prepared by the present invention are placed in a 300 mL glass bottle filled with 20% NaOH aqueous solution, sealed, and then placed in an oven at 70°C for 24 hours, then the glass bottle is taken out of the oven, cooled to room temperature, the sample piece is taken out, rinsed with tap water for 2-3 minutes, then the sample piece is placed in deionized water and soaked for 2 hours, then taken out and dried, and then placed in a 50°C oven for constant temperature baking for 48 hours. The dried sample piece is then subjected to a tensile test according to the national standard GB / T 528-2009, and the testing instrument is Hongtuo HT-140SC-020. The average value of the tensile strength of the three sample pieces tested is calculated and divided by the average value of the tensile strength before hydrolysis to obtain the percentage value of the hydrolysis resistance.

[0151] (3) Peel strength with nylon plastic sheet

[0152] A PA6 nylon sheet (Dongguan Yuancheng Plastic Material Co., Ltd., 1 mm thick, 300 mm × 300 mm) was taken, and a 100 μm portion of the aqueous polyurethane resin emulsion prepared by the present invention (pre-diluted to 20% solid content) was scraped on one side, first dried at room temperature for 1 hour, then placed in a 100°C oven for constant temperature baking for 48 hours, and then taken out, and after cooling in an environment of 23°C and 50% humidity, the coated area was cut into 30 mm × 30 mm test samples for a total of 6 pieces, and the adhesion test was carried out according to the national standard GB / T 5210-2006. The testing instrument was Hongtuo HT-140SC-020, and the adhesive used was purchased from a commercially available 502 type adhesive. The curing time was 10 minutes, and the peel strength results corresponding to the damage area ≥ 20% were selected to calculate the average value.

[0153] Table 3:

[0154]

[0155] As shown in Table 3, Examples 9-23 of the present invention synthesize waterborne polyurethanes having amidoalkyl ester structural units by introducing polymer polyols having amidoalkyl ester structural units, which can greatly improve the tensile strength of polyurethanes while keeping the flexibility of polyurethanes not greatly reduced, and greatly improve the hydrolysis resistance of polyurethanes, and improve the bonding strength between the sizing agent and the nylon matrix in the application of waterborne polyurethanes as reinforced glass fiber sizing agents. However, the waterborne polyurethanes prepared in Comparative Examples 1-4, due to the lack of amidoalkyl ester structural units, cannot have both good mechanical strength and flexibility, and the water resistance and bonding strength with the nylon matrix are also significantly reduced relative to Examples 9-23.

[0156] For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, without having to go through creative labor. Therefore, simple improvements made to the present invention by those skilled in the art based on the disclosure of the present invention should be within the protection scope of the present invention. The above embodiments are preferred embodiments of the present invention, and all processes similar to the present invention and equivalent changes made should belong to the protection scope of the present invention.

Claims

1. A waterborne polyurethane, characterized in that: The waterborne polyurethane is obtained by reacting a polyol and an isocyanate compound, wherein the polyol comprises a first polyol and a second polyol, wherein the chemical structure of the first polyol is as shown in formula (1), and the second polyol is a hydrophilic polyol; Where: s is 2, 3 or 4, t is 2, 3 or 4, m>1, n>1; R1 is selected from substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl, C2-C6 alkyl or polyether structure, and the substitution refers to substitution with alkyl.

2. The aqueous polyurethane according to claim 1, characterized in that The R1 is selected from one of the following chemical structures:

3. The aqueous polyurethane according to claim 1, characterized in that The second polyol is selected from at least one of polyethylene glycol, linear bifunctional polyethylene glycol monomethyl ether, dimethylol propionic acid, dimethylol butyric acid, and N-methyldiethanolamine; And / or, the isocyanate compound is at least one selected from toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate trimer.

4. The waterborne polyurethane according to claim 1, characterized in that In the first polyol, the mass content of amide groups is ≥ 2%; and / or, in the polyol, the mass proportion of the first polyol is ≥5%; and / or, in the polyol, the mass proportion of the second polyol is 2-40%; And / or, the molar ratio of the total molar number of hydroxyl groups in the polyol to the isocyanate groups in the isocyanate compound is 1:(1.1-2.5).

5. The waterborne polyurethane according to claim 1, characterized in that The polyol further comprises a third polyol, the third polyol is selected from at least one of ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, ethyl butyl propylene glycol, 1,4-cyclohexanedimethanol, trimethylolpropane, and a polyol, and the polyol is selected from at least one of polyester polyol, polyether polyol, polytetramethylene glycol, polycaprolactone polyol, and polycarbonate polyol; And / or, in the polyol, the mass of the third polyol accounts for 0-95%.

6. A method for preparing an aqueous polyurethane according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) under the action of a catalyst, adding a cyclic lactone dropwise to a polyamine containing a first solvent to carry out a ring-opening reaction to obtain a first polyol having an amide alkyl ester structural unit; (2) adding the first polyol, the second polyol and the isocyanate compound into a second solvent to carry out a polycondensation reaction to obtain a prepolymer; (3) After neutralizing the prepolymer, dispersing it in water, adding a chain extender to react, and obtaining the waterborne polyurethane.

7. The method for preparing waterborne polyurethane according to claim 6, characterized in that: In step (1), the cyclic lactone is selected from at least one of butyrolactone, valerolactone and caprolactone; And / or, the polyamine is at least one selected from ethylenediamine, propylenediamine, butylenediamine, pentanediamine, hexamethylenediamine, isophoronediamine, p-xylylenediamine, m-xylylenediamine, and polyetheramine; And / or, the catalyst is selected from at least one of n-butyltin oxide, dibutyltin oxide, stannous octoate, dibutyltin dilaurate, n-butyl titanate, and tetraisopropyl titanate; and / or, the first solvent is selected from at least one of N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-dimethylpropionamide; and / or, the molar ratio of the polyamine to the cyclic lactone is 1:(4-20); And / or, the ring-opening reaction is carried out at 40-120° C. for 2-7 hours.

8. The method for preparing waterborne polyurethane according to claim 6, characterized in that: In step (2), the second solvent is selected from at least one of N-methylpyrrolidone, N-ethylpyrrolidone, N-butylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, acetone, and butanone; And / or, the polycondensation reaction is carried out at 60-100° C. for 2-12 hours.

9. The method for preparing waterborne polyurethane according to claim 6, characterized in that: In step (3), the neutralization adopts an acid or a base, the acid is selected from at least one of formic acid, acetic acid, lactic acid, and methanesulfonic acid, and the base is selected from at least one of triethylamine and N,N-dimethylcyclohexylamine; And / or, the chain extender is selected from at least one of hydrazine hydrate, ethylenediamine, 1,6-hexanediamine, isophoronediamine, p-phenylenediamine, m-phenylenediamine, aminosulfonate chain extender, silane coupling agent, and deionized water.

10. A wetting agent, characterized in that The wetting agent comprises the waterborne polyurethane according to any one of claims 1 to 5.

Images