Single-component fluorine-free high-hydrophobic polyurethane waterproof coating and preparation method thereof

Abstract

The application belongs to the technical field of polyurethane waterproof coating and specifically relates to a single-component fluorine-free high-hydrophobic polyurethane waterproof coating and a preparation method thereof, which is composed of the following raw materials in parts by weight: composite polyether polyol: 60-80 parts; silane modified polyether polyol: 20-40 parts; diisocyanate: 11-17 parts; chain extender: 2-5 parts; plasticizer: 50-70 parts; filler: 50-70 parts; catalyst: 0.15-0.2 parts; and auxiliary agent: 3-5 parts. The polyurethane waterproof coating is chemically modified to introduce polyoxyamylene ether chain segments, castor oil base structures and silane groups into the molecular structure of the waterproof coating, so that the intrinsic hydrophobicity and mechanical properties of the material are improved, and the migration defects caused by the addition of hydrophobic agents and silicone oil in the traditional preparation method are solved. The application also provides a preparation method.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polyurethane waterproof coating, and particularly relates to a single-component fluorine-free high-hydrophobic polyurethane waterproof coating and a preparation method thereof. BACKGROUND

[0002] Polyurethane waterproof coating is one of important directions of application of polyurethane synthetic materials. The polyurethane coating film has the following significant advantages: excellent elasticity and extensibility, strong adhesion and low volume shrinkage, no joint of the formed waterproof layer, strong adaptability to base layer crack expansion and deformation, and convenient construction and maintenance. According to the composition, the polyurethane waterproof coating can be divided into single-component polyurethane waterproof coating and double-component polyurethane waterproof coating. Compared with the double-component polyurethane waterproof coating, the single-component waterproof coating can be used on site, is convenient to construct, does not need to use large mixing equipment for operation, and has low requirement on the water content of the base surface, and can be constructed under the condition of high humidity.

[0003] CN116970339B discloses a single-component self-cleaning polyurethane waterproof coating and a preparation method thereof. A benzene ring and a fluorosilicon chain segment are introduced into the molecular structure to improve the hydrophobicity of the material. However, the fluorine element in the raw material may be released into the environment during use, causing environmental pollution. CN116875174A discloses a silane-modified polyurethane waterproof coating and a preparation method thereof. The tensile strength, adhesive strength and waterproof performance of the polyurethane waterproof coating are improved to some extent. However, the hardness is low, the friction resistance is poor, and the application effect is not good in some high-strength stress places such as parking lots and people's roofs. The waterproof layer is easily damaged in a short period of time, and cannot achieve long-lasting waterproof effect. CN119639319A discloses a silane-modified polyether waterproof coating and a preparation method for improving its hydrophobicity. The polyether molecular structure is capped with silane, and siloxane chain segments are introduced to improve the hydrophobicity of the material. However, in a long-term waterlogged or high-humidity environment, the alkoxy group will be converted to hydroxyl group, reducing the hydrophobicity of the polyether and affecting the use effect of the waterproof coating. CN111518255B discloses a transparent hydrophobic silicon-fluorine-containing polyurethane coating and a preparation method thereof. Silicon and fluorine elements are introduced into the polyurethane through free radical polymerization to improve the hydrophobicity of the coating film. However, the actual water contact angle of the obtained coating is only 103°, and the hydrophobic effect is not ideal. CN115651524A discloses a high-strength self-cleaning polyurethane waterproof coating and a preparation method thereof. The hydrophobicity of the material is achieved by introducing self-made polyfluorosiloxane and hydroxyl-containing nano filler. However, the combination of the material with other raw materials in the formula is not good, which may cause sedimentation. CN112940598A discloses an ultra-hydrophobic waterborne polyurethane waterproof coating, which is composed of water, pH adjuster, hydroxyethyl cellulose, polyurethane emulsion, preservative, wetting dispersant, defoamer, titanium white, modified barium sulfate, anti-freezing agent and thickening agent. By screening and dosage ratio research of polyurethane emulsion and additives, an ultra-hydrophobic waterborne polyurethane waterproof coating is developed, with a 30d water absorption rate of 3.4%, and the waterproof effect is poor. CN113603881A discloses a fluorinated polytetrahydrofuran diol, a preparation method thereof, a fluorine-containing polyurethane waterproof coating, a composition thereof, a preparation method and application thereof. The hydrophobicity of the material is improved by using fluorinated polytetrahydrofuran diol. However, liquid nitrogen and acetone, an organic solvent prone to be toxic and explosive, are used in the preparation process. The contact angle of the prepared waterproof coating is 110°, and the hydrophobicity needs to be improved. SUMMARY

[0004] To solve the above technical problems, the application provides a single-component fluorine-free high-hydrophobic polyurethane waterproof coating, which introduces polyoxyamylene ether chain segments, castor oil base structures and silane groups into the molecular structure of the waterproof coating by chemical modification, improves intrinsic hydrophobicity and mechanical properties of the material, and solves the migration defects caused by the addition of hydrophobic agents and silicone oil in the traditional preparation method.

[0005] The single-component fluorine-free high-hydrophobic polyurethane waterproof coating provided by the application is composed of the following raw materials in parts by weight:

[0006] The composite polyether polyol is 60-80 parts;

[0007] The silane-modified polyether polyol is 20-40 parts;

[0008] The diisocyanate is 11-17 parts;

[0009] The chain extender is 2-5 parts;

[0010] The plasticizer is 50-70 parts;

[0011] The filler is 50-70 parts;

[0012] The catalyst is 0.15-0.2 parts;

[0013] The auxiliary agent is 3-5 parts;

[0014] The composite polyether polyol is obtained by polymerizing propylene oxide and 1,2-epoxyhexane under the action of a DMC catalyst, with castor oil and pentaerythritol polyether polyol as starting agents, and 1,2-epoxyhexane accounts for 50%-70% of the total mass of the castor oil, the pentaerythritol polyether polyol, the propylene oxide and the 1,2-epoxyhexane, the number average molecular weight is 5000 g•mol -1 , and the functionality is 3; wherein the functionality of the castor oil is 2.7, and the hydroxyl value is 162 mgKOH / g; the pentaerythritol polyether polyol is obtained by polymerizing propylene oxide under the action of a KOH catalyst, with pentaerythritol as a starting agent, the number average molecular weight is 800 g•mol -1 , and the functionality is 4;

[0015] The preparation steps of the silane-modified polyether polyol are as follows: esterification reaction is performed on sorbitol polyether polyol and oleic acid, and then addition reaction is performed on alkyl hydrogen silane after the reaction is completed, and the silane-modified polyether polyol is obtained; wherein the sorbitol polyether polyol is obtained by polymerizing propylene oxide under the action of a KOH catalyst, with sorbitol as a starting agent, the number average molecular weight is 1500 g•mol -1 , and the functionality is 6; the alkyl hydrogen silane is one of diethylmethyl hydrogen silane and triethyl hydrogen silane.

[0016] Preferably, the preparation steps of the silane-modified polyether polyol are as follows: sorbitol polyether polyol, oleic acid and p-toluene sulfonic acid are added into a reaction kettle with a condenser, nitrogen is introduced to replace 3 times, the temperature is raised to 150-170 DEG C, and the reaction is stirred, the by-products are continuously separated and distilled off through the rectifying column during the reaction, the reaction is carried out for 6-8 hours, the temperature is lowered to 80-100 DEG C, alkylsilane and chloroplatinic acid catalyst are added, and the reaction is carried out for 4-6 hours; and after the carbon-carbon double bond peak disappears at 1640 cm -1 , the addition reaction is completed, and the silane-modified polyether polyol is prepared; the molar ratio of the sorbitol polyether polyol, the oleic acid and the alkylsilane is 1:4.08:4; and the amount of the chloroplatinic acid catalyst is 70-100 ppm of the total amount of the sorbitol polyether polyol, the oleic acid and the alkylsilane.

[0017] Preferably, the diisocyanate is one of hexamethylene diisocyanate and diphenylmethane diisocyanate.

[0018] Preferably, the filler is one or more of kaolin, fumed silica or calcium carbonate.

[0019] Preferably, the chain extender is bisphenol A dihydroxypropyl ether, the molecular formula is C 21 H 28 O4, the CAS number is 116-37-0, and the benzene ring structure in the molecule can improve the hydrophobicity and adhesion of the material.

[0020] Preferably, the plasticizer is one of chlorinated paraffin, epoxy soybean oil and triethyl phosphate.

[0021] Preferably, the catalyst is dibutyltin dilaurate.

[0022] Preferably, the auxiliary agent is a silicone defoaming agent.

[0023] The preparation method of the one-component fluorine-free high-hydrophobic polyurethane waterproof coating disclosed by the application comprises the following steps:

[0024] S1, the composite polyether polyol, the silane-modified polyether polyol, the filler and the plasticizer are added into a reaction kettle, the temperature is raised to 100-110 DEG C, and vacuum dehydration is carried out until the water content is below 0.04%;

[0025] S2, the temperature is lowered to 60-70 DEG C, the diisocyanate is added, the reaction is carried out at 70-80 DEG C for 3-4 hours, and then the chain extender is added to continue the reaction for 2-3 hours;

[0026] S3, after the -NCO% reaches 0.93%-1.15%, the temperature is lowered to 20-40 DEG C, the catalyst and the auxiliary agent are added, and stirring is uniformly carried out, so that the one-component fluorine-free high-hydrophobic polyurethane waterproof coating is obtained.

[0027] Compared with the prior art, the application has the following beneficial effects:

[0028] 1、The composite polyether polyol of the present application can achieve intrinsic waterproof performance improvement by introducing castor oil base and epoxidized hexene ether segments into the polyether polyol structure, and can improve the mechanical properties of the waterproof coating by improving the crosslinking density of the system through the design of the functionality of the composite polyether polyol.

[0029] 2、The silane-modified polyether polyol of the present application introduces hydrophobic silicon-containing segments into the high-functionality polyether polyol structure through the bridging of oleic acid, and the high-functionality polyether polyol can introduce more oleic acid long chains and silicon-containing segments to construct a hydrophobic surface, effectively reduce the surface energy of the coating, further improve the intrinsic hydrophobicity of the material, and improve the stability and service life of the waterproof coating.

[0030] 3、The one-component fluorine-free high-hydrophobic polyurethane waterproof coating of the present application discards fluorine-containing compounds, eliminates the risk of fluoride emission from the source, and has the characteristics of environmental friendliness and health safety during use. DETAILED DESCRIPTION

[0031] The technical solutions of the present application will be described below in conjunction with the examples.

[0032] All the raw materials used in the examples are commercially available, except for special instructions.

[0033] Some of the raw materials used in the examples and comparative examples are described as follows:

[0034] INOVOLF330N (glyceryl polyether, functionality 3, number average molecular weight 5000 g•mol -1 ), Shandong Inovol New Material Co., Ltd.

[0035] INOVOLC230 (propylene glycol polyether, functionality 2, number average molecular weight 3000 g•mol -1 ), Shandong Inovol New Material Co., Ltd.

[0036] Silicone defoamer, model: TEGOFomaex800, purchased from Yingchuang Industrial Group.

[0037] The preparation method of the pentaerythritol polyether polyol is as follows: 272 g of pentaerythritol and 4.95 g of potassium hydroxide catalyst are added to a high-pressure reaction kettle, nitrogen is replaced for three times, and then the temperature is raised to 110℃, and dehydrated for 2 h. 1378 g of propylene oxide is continuously added to the reaction kettle, the reaction temperature is controlled at 110℃, the pressure in the kettle is ≤0.3 MPa, and after the reaction is completed, aging for 4 h, and monomer removal for 0.5 h, the pentaerythritol polyether polyol is prepared after acid water refining treatment, with a hydroxyl value of 280.5 mgKOH / g and a number average molecular weight of 800 g•mol -1 .

[0038] The preparation method of the composite polyether polyol is: 715 g of castor oil, 188 g of pentaerythritol polyether polyol, and 0.2 g of DMC catalyst are added to a high-pressure reaction kettle, heated to 130°C, and 45 g of propylene oxide is added dropwise to initiate. After the pressure drops to -0.08 MPa, the remaining 570 g of propylene oxide and 3542 g of 1,2-epoxyhexane are gradually added dropwise into the reaction kettle, and the pressure in the reaction kettle is controlled to be ≤0.3 MPa. After the reaction is completed, the monomer is removed for 0.5 h to prepare the composite polyether polyol, the functionality is 3, the hydroxyl value is 33.66 mgKOH / g, and the number average molecular weight is 5000 g•mol -1 .

[0039] The preparation method of the sorbitol polyether polyol is: 182 g of sorbitol and 4.65 g of potassium hydroxide catalyst are added to a high-pressure reaction kettle, and after nitrogen replacement for three times, the temperature is raised to 110°C and dehydrated for 2 h. 1368 g of propylene oxide is continuously added into the reaction kettle, the reaction temperature is controlled at 110°C, and the pressure in the kettle is ≤0.3 MPa. After the reaction is completed, aging for 4 h, and monomer removal for 0.5 h, the sorbitol polyether polyol is prepared after acid water refining treatment, with a hydroxyl value of 112.2 mgKOH / g and a number average molecular weight of 1500 g•mol -1 .

[0040] Example 1

[0041] The preparation steps of the silane-modified polyether polyol in this example 1 are: 500 g of sorbitol polyether polyol, 383.52 g of oleic acid, and 8.84 g of p-toluenesulfonic acid are added to a reaction kettle with a condenser, nitrogen is introduced for replacement for three times, the temperature is raised to 160°C, and the reaction is stirred. During the reaction, the by-products are continuously separated and distilled off through the rectifying column, and the reaction is carried out for 8 h. The temperature is lowered to 80°C, 136 g of diethylmethylsilane and 0.08 g of chloroplatinic acid catalyst are added, and the reaction is carried out for 5 h. After the carbon-carbon double bond peak at 1640 cm -1 in the infrared test wave number disappears, the addition reaction is completed, and the silane-modified polyether polyol is prepared.

[0042] The single-component fluorine-free high-hydrophobic polyurethane waterproof coating comprises the following raw materials in parts by weight:

[0043] The composite polyether polyol is 70 parts;

[0044] The silane-modified polyether polyol (Mn is 3036 g•mol -1 ) is 30 parts;

[0045] The hexamethylene diisocyanate is 11 parts;

[0046] The bisphenol A dihydroxypropyl ether is 3 parts;

[0047] Kaolin: 40 parts;

[0048] Fumed silica: 30 parts;

[0049] Chlorinated paraffin: 50 parts;

[0050] Dibutyltin dilaurate: 0.15 parts;

[0051] Silicone defoamer TEGO Foma ex800: 5 parts.

[0052] The preparation method of the single-component fluorine-free high-hydrophobic polyurethane waterproof coating comprises the following steps:

[0053] S1, the composite polyether polyol, the silane modified polyether polyol, the filler kaolin, the fumed silica and the plasticizer chlorinated paraffin are added into a reaction kettle, the temperature is raised to 110 DEG C, and vacuum dehydration is carried out for 1.5 h to the moisture content below 0.04%;

[0054] S2: the temperature is lowered to 60 DEG C, hexamethylene diisocyanate is added, and reaction is carried out at 75 DEG C for 4 h, then bisphenol A dihydroxypropyl ether is added and reaction is continued for 3 h;

[0055] S3: after the -NCO% reaches 0.93%, the temperature is lowered to 30 DEG C, the catalyst dibutyltin dilaurate and the silicone defoamer TEGO Foma ex800 are added, and stirring is uniformly carried out, thereby obtaining the single-component fluorine-free high-hydrophobic polyurethane waterproof coating.

[0056] Example 2

[0057] The preparation steps of the silane modified polyether polyol in this example 2 are as follows: 500 g sorbitol polyether polyol, 383.52 g oleic acid and 7.07 g p-toluenesulfonic acid are added into a reaction kettle with a condenser, nitrogen is introduced to replace 3 times, the temperature is raised to 150 DEG C, stirring reaction is carried out, byproduct is continuously separated and evaporated through the rectifying column during the reaction, reaction is carried out for 7 h; the temperature is lowered to 90 DEG C, 136 g diethylmethylsilane and 0.071 g chloroplatinic acid catalyst are added, reaction is carried out for 6 h, and the carbon-carbon double bond peak disappears at the infrared test wave number of 1640 cm -1 -1, thereby completing the addition reaction and preparing the silane modified polyether polyol.

[0058] The single-component fluorine-free high-hydrophobic polyurethane waterproof coating is composed of the following raw materials in parts by weight:

[0059] Composite polyether polyol: 60 parts;

[0060] Silane modified polyether polyol (Mn is 3036 g•mol -1 ): 40 parts;

[0061] Diphenylmethane diisocyanate: 17 parts;

[0062] Bisphenol A dihydroxypropyl ether: 2 parts;

[0063] Fumed silica: 20 parts;

[0064] Calcium carbonate: 30 parts;

[0065] Epoxidized soybean oil: 70 parts;

[0066] Dibutyltin dilaurate: 0.2 parts;

[0067] Silicone defoamer TEGO Fomaex 800: 4 parts.

[0068] The preparation method of the single-component fluorine-free high-hydrophobic polyurethane waterproof coating comprises the following steps:

[0069] S1, the composite polyether polyol, the silane modified polyether polyol, the filler fumed silica, the calcium carbonate and the plasticizer epoxidized soybean oil are added into a reaction kettle, the temperature is raised to 100℃, and vacuum dehydration is carried out for 2.5h to make the moisture content below 0.04%;

[0070] S2: the temperature is lowered to 70℃, diphenylmethane diisocyanate is added, and reaction is carried out at 70℃ for 4h, then bisphenol A dihydroxypropyl ether is added and reaction is continued for 2h;

[0071] S3: after the -NCO% reaches 1.1%, the temperature is lowered to 20℃, the catalyst dibutyltin dilaurate and the silicone defoamer TEGO Fomaex 800 are added, and stirring is uniformly carried out, so that the single-component fluorine-free high-hydrophobic polyurethane waterproof coating is obtained.

[0072] Example 3

[0073] The preparation steps of the silane modified polyether polyol in this example 3 are as follows: 500g sorbitol polyether polyol, 383.52g oleic acid and 13.25g p-toluenesulfonic acid are added into a reaction kettle with a condenser, nitrogen is introduced to replace 3 times, the temperature is raised to 170℃, stirring reaction is carried out, byproduct is continuously separated and evaporated through the rectifying column during the reaction, reaction is carried out for 6h; the temperature is lowered to 100℃, 154.67g triethylsilane and 0.10g chloroplatinic acid catalyst are added, reaction is carried out for 4h, and the carbon-carbon double bond peak disappears at the infrared test wave number of 1640cm -1 -1, so that the addition reaction is completed, and the silane modified polyether polyol is prepared.

[0074] The single-component fluorine-free high-hydrophobic polyurethane waterproof coating is composed of the following raw materials in parts by weight:

[0075] Composite polyether polyol: 80 parts;

[0076] Silane modified polyether polyol (Mn is 3092g•mol -1 ): 20 parts;

[0077] Hexamethylene diisocyanate: 13 parts;

[0078] Bisphenol A dihydroxypropyl ether: 5 parts;

[0079] Kaolin: 25 parts;

[0080] Calcium carbonate: 35 parts;

[0081] Triethyl phosphate: 60 parts;

[0082] Dibutyltin dilaurate: 0.18 parts;

[0083] TEGOFomaex 800 silicone defoamer: 3 parts.

[0084] The preparation method of the single-component fluorine-free highly hydrophobic polyurethane waterproof coating comprises the following steps:

[0085] S1. Add the composite polyether polyol, silane-modified polyether polyol, filler kaolin, calcium carbonate and plasticizer triethyl phosphate into the reactor, heat to 110°C, and dehydrate under vacuum for 1.5 hours until the moisture content is below 0.04%.

[0086] S2: Cool to 70℃, add hexamethylene diisocyanate, react at 80℃ for 3 hours, then add bisphenol A dihydroxypropyl ether and continue the reaction for 2 hours;

[0087] After S3: -NCO% reaches 1.15%, the temperature is lowered to 40℃, and the catalyst dibutyltin dilaurate and the organosilicon defoamer TEGOFomaex800 are added and stirred evenly to obtain a single-component fluorine-free, highly hydrophobic polyurethane waterproof coating.

[0088] Comparative Example 1

[0089] The difference between Comparative Example 1 and Example 1 is that INOVOLF330N of equal mass is used instead of the composite polyether polyol.

[0090] Comparative Example 2

[0091] The difference between Comparative Example 2 and Example 1 is that INOVOLC230 of equal mass is used instead of silane-modified polyether polyol.

[0092] Comparative Example 3

[0093] The difference between Comparative Example 3 and Example 1 is that INOVOLF330N was used in place of the composite polyether polyol by mass; and INOVOLC230 was used in place of the silane-modified polyether polyol by mass.

[0094] Comparative Example 4

[0095] The difference between the present comparative example 4 and example 1 is that propylene glycol-based polyoxypropylene ether diol (Mn is 344 g·mol -1 ) is used instead of bisphenol A dihydroxypropyl ether.

[0096] Comparative example 5

[0097] The difference between the present comparative example 5 and example 1 is that castor oil-based polyether polyol (polymerized by catalyzing propylene oxide and 1,2-epoxyhexane with DMC catalyst, using castor oil as a starting agent, wherein 60% of the total mass of 1,2-epoxyhexane castor oil, propylene oxide and 1,2-epoxyhexane) is used instead of composite polyether polyol. -1

[0098] The polyurethane waterproof coating obtained from the examples and comparative examples is tested according to the test standards in GB / T 19250-2013 and GB / T 30693-2014, and the test results are shown in Table 1.

[0099] Table 1 Performance test results of examples and comparative examples

[0100]

[0101] As can be seen from the data in Table 1, the one-component fluorine-free high-hydrophobic waterproof coating of examples 1-3 can have good mechanical properties and excellent high-hydrophobicity. The composite polyether polyol synthesized by copolymerizing propylene oxide and epoxyhexane with a composite starting agent is used to prepare a waterproof coating, and the water absorption is significantly lower than that of a waterproof coating prepared by a conventional polyether, which is because the long carbon chain in the castor oil molecule and the side chain of 1,2-epoxyhexane can be arranged in the direction on the surface of the coating, forming a hydrophobic layer, and by designing the functionality of the composite polyether polyol, more crosslinking points can be formed in the reaction, improving the mechanical properties of the waterproof coating; the esterification of high-functionality polyether polyol with oleic acid introduces a silicon-containing segment, and the ester bond can greatly improve the adhesion of the coating film to the substrate, and the long carbon chain in the silicon-containing segment and the oleic acid structure can form a low-surface-energy silane network structure on the surface of the coating, significantly reducing the affinity of the coating to water, increasing the water contact angle, and reducing water penetration; in addition, the benzene ring structure in the chain extender can further improve the hydrophobicity of the material. The improvement of the above-mentioned properties can greatly improve the application scenarios of polyurethane waterproof coating in outdoor or harsh environmental conditions. Compared with example 1, the replacement of the composite polyether polyol with castor oil polyether polyol using only castor oil as a starting agent reduces the functionality, which increases the elongation at break, and the hydrophobic effect is slightly better due to the more hydrophobic castor oil, but the mechanical strength such as tensile and tear is significantly reduced, therefore, the present application can balance the mechanical strength and hydrophobicity.​

Claims

1. A single-component fluorine-free high-hydrophobic polyurethane waterproof coating, characterized by, The single-component fluorine-free high-hydrophobic polyurethane waterproof coating is prepared from the following raw materials by weight: The composite polyether polyol is 60-80 parts. The silane-modified polyether polyol is 20-40 parts. The diisocyanate is 11-17 parts. The chain extender is 2-5 parts. The plasticizer is 50-70 parts. The filler is 50-70 parts. The catalyst is 0.15-0.2 parts. The auxiliary agent is 3-5 parts. The composite polyether polyol is prepared by polymerizing propylene oxide and 1,2-epoxyhexane under the action of DMC catalyst, with castor oil and pentaerythritol polyether polyol as starting agents, and the mass percentage of 1,2-epoxyhexane in the total mass of castor oil, pentaerythritol polyether polyol, propylene oxide and 1,2-epoxyhexane is 50%-70%, the number average molecular weight is 5000 g•mol -1 , and the functionality is 3; wherein the pentaerythritol polyether polyol is prepared by polymerizing propylene oxide under the action of KOH catalyst, with pentaerythritol as a starting agent, the number average molecular weight is 800 g•mol -1 , and the functionality is 4; The preparation steps of the silane-modified polyether polyol are: esterification reaction of sorbitol polyether polyol and oleic acid, and then addition reaction of alkyl hydrogen silane after the reaction is completed, and the silane-modified polyether polyol is obtained; wherein the sorbitol polyether polyol is obtained by polymerization of propylene oxide under the action of KOH catalyst with sorbitol as a starter, and the number average molecular weight is 1500 g•mol -1 , and the functionality is 6; and the alkyl hydrogen silane is one of diethylmethyl hydrogen silane and triethyl hydrogen silane.

2. The one-component fluorine-free high-hydrophobic polyurethane waterproof coating according to claim 1, characterized by, The preparation steps of the silane-modified polyether polyol are: adding sorbitol polyether polyol, oleic acid and p-toluenesulfonic acid into a reaction kettle with a condenser, replacing three times by nitrogen, heating to 150-170 DEG C, stirring and reacting, continuously separating and evaporating by-products through a rectifying column during the reaction, reacting for 6-8 h; cooling to 80-100 DEG C, adding alkylsilane and chloroplatinic acid catalyst, reacting for 4-6 h, and the carbon-carbon double bond peak disappears at an infrared test wave number of 1640 cm -1 After the addition reaction is completed, the silane-modified polyether polyol is prepared; the molar ratio of sorbitol polyether polyol, oleic acid and alkylsilane is 1:4.08:4; the amount of chloroplatinic acid catalyst is 70-100 ppm of the total amount of sorbitol polyether polyol, oleic acid and alkylsilane. 3.The single-component fluorine-free high-hydrophobic polyurethane waterproof coating of claim 1, characterized in that, The diisocyanate is one of hexamethylene diisocyanate and diphenyl methane diisocyanate.

4. The one-component fluorine-free high-hydrophobic polyurethane waterproof coating according to claim 1, characterized by, The filler is one or more of kaolin, fumed silica or calcium carbonate. 5.The single-component fluorine-free high-hydrophobic polyurethane waterproof coating of claim 1, characterized in that, The chain extender is bisphenol A dihydroxypropyl ether. 6.The single-component fluorine-free high-hydrophobic polyurethane waterproof coating of claim 1, characterized in that, The plasticizer is one of chlorinated paraffin, epoxy soybean oil or triethyl phosphate. 7.The one-component fluorine-free high-hydrophobic polyurethane waterproof coating of claim 1, characterized in that, The catalyst is dibutyl tin dilaurate. 8.The single-component fluorine-free high-hydrophobic polyurethane waterproof coating of claim 1, characterized in that, The auxiliary agent is a silicone defoaming agent.

9. A process for the preparation of one-component fluorine-free highly hydrophobic polyurethane water repellent coating as claimed in any one of claims 1 to 8, characterized in that, The steps are as follows: S1. The composite polyether polyol, the silane-modified polyether polyol, the filler, the plasticizer are added into a reaction kettle, heated to 100-110℃, vacuum dewatered to a moisture content of less than 0.04%; S2. The temperature is lowered to 60-70℃, the diisocyanate is added, reacted at 70-80℃ for 3-4h, then the chain extender is added and reacted for 2-3h; S3. After the -NCO% reaches 0.93%-1.15%, the temperature is lowered to 20-40℃, the catalyst and the auxiliary agent are added, stirred uniformly, and the single-component fluorine-free high-hydrophobic polyurethane waterproof coating is obtained.

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