CN112851903B - Preparation method of organic silicon modified waterborne polyurethane and product thereof - Google Patents

Abstract

The invention discloses a preparation method of organic silicon modified waterborne polyurethane and a product thereof, wherein the preparation method comprises the following steps: (1) Eugenol and 1, 3-tetramethyl disiloxane are taken as raw materials, and eugenol diphenol is synthesized through hydrosilylation reaction; (2) Diisocyanate, polyester polyol, eugenol diphenol and polyhydroxy hydrophilic chain extender are used as raw materials, and after polymerization reaction, the raw materials are subjected to neutralization reaction with an alkaline neutralizer to obtain a waterborne polyurethane prepolymer; (3) And mixing the aqueous polyurethane prepolymer, water and a post-chain extender, and carrying out chain extension reaction to obtain the organic silicon modified aqueous polyurethane. The organic silicon modified waterborne polyurethane prepared by the method has excellent mechanical properties and water resistance, is good in storage stability, and has great application potential in the fields of food packaging, coatings, adhesives, particularly adhesives for textile fabrics and the like.

Description

Preparation method of organic silicon modified waterborne polyurethane and product thereof

Technical Field

The invention relates to the technical field of waterborne polyurethane, in particular to a preparation method of organic silicon modified waterborne polyurethane and a product thereof.

Background

The waterborne polyurethane is used as a green and environment-friendly material, and can be widely applied to various fields of adhesives, coatings, printing ink, biological medicine and the like. Since water is used as a solvent and a film forming mechanism is changed, the aqueous polyurethane often exhibits lower water resistance and mechanical properties than conventional polyurethanes, which somewhat limits the application range thereof.

In recent years, there are many reports on silicone-modified aqueous polyurethanes, and these are generally classified into physical blending and copolymerization modification. Physical blending typically incorporates various types of nanocomposites in the aqueous polyurethane to enhance performance, including silica, cellulose nanocrystals, graphene, polysilsesquioxanes, and the like. Although the modification mode is simple and feasible, the performance improvement of the prepared product is limited and the storage stability is relatively poor.

The copolymerization modification is usually carried out by modifying with a siloxane having a terminal hydroxyl group or a terminal amino group. For example, chinese patent publication No. CN 111995943A discloses an organosilicon modified aqueous polyurethane waterproof coating and a preparation method thereof. The raw materials comprise: 100 parts of polyalcohol and polyisocyanate, 4-6 parts of hydrophilic chain extender, 3-7 parts of post chain extender, 0.05-0.3 part of neutralizer, 1.5-2 parts of KH-550 coupling agent, 10-25 parts of auxiliary agent, 20-50 parts of filler and 25-40 parts of water. The preparation method comprises the steps of carrying out prepolymerization reaction on polyol, polyisocyanate and a catalyst to obtain a first prepolymer; sequentially adding a hydrophilic chain extender and a non-hydrophilic chain extender into the first prepolymer for chain extension reaction to obtain a second prepolymer, and performing neutralization reaction with a neutralizer to obtain a waterborne polyurethane prepolymer; and then mixing the waterborne polyurethane prepolymer with KH-550 for modification to obtain a waterborne polyurethane dispersion, finally performing an emulsification reaction to obtain a waterborne polyurethane emulsion, and mixing the waterborne polyurethane emulsion with an auxiliary agent to obtain the organic silicon modified waterborne polyurethane waterproof coating.

The technical scheme utilizes KH-550 coupling agent to modify waterborne polyurethane, and aims to improve the mechanical property, the dirt resistance and the hydrophobic property of the product organosilicon modified waterborne polyurethane waterproof coating. However, according to the data recorded, the mechanical properties and hydrophobic properties of the product are not ideal, and the application of the product has certain limitations.

Disclosure of Invention

Aiming at the problems in the prior art, the invention discloses a preparation method of organic silicon modified waterborne polyurethane, and the prepared organic silicon modified waterborne polyurethane has excellent mechanical property and water resistance, is good in storage stability, and has great application potential in the fields of food packaging, adhesives, coatings and the like.

The specific technical scheme is as follows:

a preparation method of organosilicon modified waterborne polyurethane comprises the following steps:

(1) Eugenol and 1, 3-tetramethyl disiloxane are taken as raw materials, and eugenol diphenol is synthesized by hydrosilylation reaction;

(2) Diisocyanate, polyester polyol, the eugenol diphenol prepared in the step (1) and a polyhydroxy hydrophilic chain extender are used as raw materials, and after polymerization reaction, the eugenol diphenol and the polyhydroxy hydrophilic chain extender are subjected to neutralization reaction with an alkaline neutralizer to obtain a waterborne polyurethane prepolymer;

(3) And mixing the aqueous polyurethane prepolymer, water and a post-chain extender, and carrying out chain extension reaction to obtain the organic silicon modified aqueous polyurethane.

The preparation method disclosed by the invention comprises the following steps of firstly, synthesizing eugenol diphenol simultaneously having a benzene ring rigid structure and a Si-O-Si flexible chain segment by using hydrosilylation reaction between eugenol and a hydrogen-containing double end socket; and then the prepolymer is introduced into a polyurethane system in the stage of synthesizing the polyurethane prepolymer, so that the prepared organic silicon modified waterborne polyurethane has excellent mechanical property and water resistance, and has great application potential in the fields of food packaging, coatings, adhesives, particularly adhesives for textile fabrics and the like.

In the step (1):

the chemical reaction formula of the hydrosilylation reaction is as follows:

the molar ratio of the eugenol to the 1, 3-tetramethyldisiloxane is 1: (50-100)%;

the temperature of the hydrosilylation reaction is 55-70 ℃, and the reaction time is 24-48 h.

The hydrosilylation reaction is carried out with a catalyst, which may be selected from the class of catalysts commonly used in the art, such as a Karster catalyst.

Preferably, the mass ratio of the eugenol to the kast catalyst is 1:2.38 percent.

In the step (2):

the diisocyanate is selected from one or more of 2, 4-toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate and 1, 6-hexamethylene diisocyanate.

Preferably, the polyester polyol is selected from the group consisting of polyethylene adipate 1, 4-butanediol glycol; the polyester polyol is prepared from adipic acid, ethylene glycol and 1, 4-butanediol serving as raw materials through esterification reaction.

The esterification reaction is carried out under the action of a catalyst, and a catalyst type commonly used in the field, such as tetraisopropyl titanate, can be selected.

Preferably:

the temperature of the esterification reaction is 135-200 ℃, and the time is 24-48 h;

the mass ratio of the 1, 6-adipic acid to the catalyst is 1:0.00714 percent.

The polyhydroxy hydrophilic chain extender is selected from 2, 2-dimethylolpropionic acid and/or 2, 2-dimethylolbutyric acid;

the mass ratio of diisocyanate to polyester polyol to eugenol diphenol to polyhydroxy hydrophilic chain extender is 1: (150 to 300)%: (1-28)%: (10-25)%.

Preferably:

the diisocyanate is selected from isophorone diisocyanate;

in the preparation of the polyester polyol, the mass ratio of adipic acid, glycol and 1, 4-butanediol is 1:24.9%:36.2 percent;

the mass ratio of diisocyanate, polyester polyol, eugenol diphenol to polyhydroxy hydrophilic chain extender is 1: (173.75-250)%: (3.75-23.75)%: (13.75-18)%;

the alkaline neutralizing agent is selected from one or more of triethylamine, ammonia water, sodium hydroxide and potassium hydroxide;

the molar ratio of the alkaline neutralizing agent to the polyhydroxy hydrophilic chain extender is 0.8-1.1: 1; more preferably 0.9:1.

under the proportion of the raw materials, the mass of the eugenol diphenol accounts for 1-8% of the total mass of the polyurethane prepolymer (including the total mass of diisocyanate, polyester polyol, eugenol diphenol, polyhydroxy hydrophilic chain extender and alkaline neutralizer).

Tests show that the product prepared under the preferable process conditions has better mechanical property and water resistance.

Preferably, the mass ratio of the polyhydroxy hydrophilic chain extender to the eugenol diphenol is 1: (20 to 175)%.

Tests show that when the using amount of the two is kept in the proper range, the prepared product has excellent room-temperature storage property and can still exist stably after being placed at room temperature for 6 months.

Further preferably:

the mass ratio of the polyhydroxy hydrophilic chain extender to the eugenol diphenol is 1: (55-65)%;

the polyhydroxy hydrophilic chain extender is selected from 2, 2-dimethylolpropionic acid.

Tests show that when the polyhydroxy hydrophilic chain extender is selected from 2, 2-dimethylolpropionic acid, the polyhydroxy hydrophilic chain extender has a synergistic effect with eugenol diphenol; further, by limiting the mass ratio of the two components to the above preferable range, the mechanical properties and water resistance of the product can be further improved.

More preferably:

the mass ratio of diisocyanate, polyester polyol, eugenol diphenol to polyhydroxy hydrophilic chain extender is 1:10.5%:225%:16.25 percent;

the molar ratio of the alkaline neutralizing agent to the polyhydroxy hydrophilic chain extender is 0.9:1;

calculated, the mass of the eugenol diphenol accounts for 3 percent of the total mass of the polyurethane prepolymer.

Tests show that under the process conditions, the mechanical property and the water resistance of the prepared product are optimal.

In the step (2), the temperature of the polymerization reaction is 75-85 ℃, the temperature is reduced to 45-55 ℃ when the NCO content in the system reaches a theoretical value (3%), and an alkaline neutralizer is added for neutralization reaction.

The polymerization reaction is carried out under the action of a catalyst, and a catalyst which is common in the field, such as dibutyltin dilaurate and the like, can be selected.

Preferably, the mass ratio of the diisocyanate to the catalyst is 1: (0.01-0.1)%.

The time of the neutralization reaction is 20-40 min.

In the step (3):

the rear chain extender is selected from one or more of ethylenediamine, 1, 4-butanediamine and hydrazine hydrate;

the mass ratio of the diisocyanate to the rear chain extender is 1: (10-15)%;

the temperature of the post chain extension reaction is 5-15 ℃, and the time is 1-2 h.

The invention also discloses the organosilicon modified waterborne polyurethane prepared by the process.

Compared with the prior art, the invention has the following advantages:

the invention discloses a preparation method of organic silicon modified waterborne polyurethane, which comprises the steps of firstly, synthesizing eugenol diphenol simultaneously having a benzene ring rigid structure and a Si-O-Si flexible chain segment by hydrosilylation reaction between eugenol and a hydrogen-containing double seal head; then the prepolymer is introduced into a polyurethane system in the stage of synthesizing the polyurethane prepolymer. The preparation process has the advantages of green and environment-friendly raw materials, simple process and controllability.

The prepared organic silicon modified waterborne polyurethane has excellent mechanical property and water resistance, and has great application potential in the fields of food packaging, coatings, adhesives, particularly adhesives for textile fabrics and the like.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of eugenol (a) and eugenol diphenol (b) prepared in example 1;

FIG. 2 is a process flow for preparing silicone-modified waterborne polyurethane of example 1;

FIG. 3 is an IR spectrum of the final product prepared in example 1, and a comparison is made with the IR spectrum of the product prepared in comparative example 1.

Detailed Description

To further clarify the objects, technical solutions and advantages of the present invention, the following detailed description of the present invention is provided with reference to specific examples, which should not be construed as limiting the scope of the present invention.

In the following examples-NCO content was determined according to HG/T2409-1992 standard.

Example 1

Step 1: preparation of polyester polyols

2800g of adipic acid, 1014g of 1, 4-butanediol, 698g of ethylene glycol and 0.2g of tetraisopropyl titanate were put into a four-necked flask, heated to 135 ℃ and distilled water was collected. After the reaction is finished, the water is weighed, and the acid value and the hydroxyl value of the prepared polyester polyol are measured.

Tests show that the structural formula of the product poly (ethylene adipate-1, 4-butanediol ester diol) is shown as the following formula, wherein a is 2 or 4, n is 1-20, the number average molecular weight is 2085g/mol, the hydroxyl value is 53.4mgKOH/g, and the acid value is 0.4mgKOH/g; the yield thereof was found to be 85%.

Step 2: preparation of eugenol diphenol

0.39g of platinum catalyst and 16.42g (0.1 mol) of eugenol were charged into a magnetically stirred three-necked flask equipped with a reflux condenser, and 20mL of toluene was added, and after 30min of nitrogen gas had been introduced, the temperature was raised to 60 ℃ and 6.70g (0.05 mol) of tetramethyldisiloxane was slowly added dropwise to the reaction system. And (4) continuously carrying out nuclear magnetism on the product in the reaction process, and observing the reaction degree of the eugenol until the nuclear magnetism spectrogram does not show double bonds any more. 4.02g (0.03 mol) of tetramethyldisiloxane were additionally added. After the reaction was completed, the solvent was removed using a rotary evaporator to obtain a pale yellow viscous liquid. The yield was 95%.

And step 3: preparation of organosilicon modified waterborne polyurethane

10.00g of polyester polyol, 0.70g of 2, 2-dimethylolpropionic acid and 0.15g of eugenol diphenol (accounting for 1 percent of the polyurethane prepolymer) are weighed and added into a 100mL four-neck flask provided with a mechanical stirring, reflux condenser and thermometer, the temperature is raised to 80 ℃, and the mixture is stirred for 30min at 200r/min under the nitrogen atmosphere. 4g of isophorone diisocyanate and 0.001g of dibutyltin dilaurate catalyst were weighed out and added into a four-necked flask together, and the reaction was continued until the NCO mass content of the system, determined by the di-n-butylamine method, reached the theoretical value (3%). The system was cooled to 50 ℃ and 0.48g triethylamine was added to neutralize the carboxyl groups. During the reaction, a small amount of acetone is added to reduce the viscosity of the system. Neutralizing for 30min, removing the oil bath pan, and cooling the reaction system to room temperature. Deionized water was added dropwise in an ice water bath and 0.44g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5h, the emulsion was transferred to a flask and the acetone was evaporated off on a rotary evaporator. And obtaining the waterborne polyurethane emulsion with the solid content of about 30 percent, which is marked as WPU1.

The test shows that the WPU1 is stable after being placed at room temperature for 6 months.

FIG. 1 is a nuclear magnetic hydrogen spectrum of eugenol (a) as a raw material and eugenol-based diphenol (b) prepared by hydrosilylation reaction, wherein a signal at 0.1ppm belongs to Si-CH ₃ The methyl hydrogen atom of (C) and the signal at 1.60ppm pertains to the methylene hydrogen atom (Si-CH) close to Si ₂ -CH ₂ ) And a double bond proton peak and a silicon-hydrogen bond peak do not appear, so that eugenol diphenol (marked as EUSi) is successfully synthesized.

FIG. 2 is a process flow for preparing the organosilicon modified waterborne polyurethane according to the embodiment; the final product has both soft segment and hard segment, the soft segment is mainly composed of polyester polyol segment, and the hard segment is composed of structure formed by reaction of polyisocyanate and small molecular chain extender.

Comparative example 1

Step 1 is the same as step 1 in example 1;

step 2: preparation of waterborne polyurethanes

10.6g of polyester polyol and 0.73g of 2, 2-dimethylolpropionic acid were weighed into a 100mL four-necked flask equipped with a mechanical stirring, reflux condenser and thermometer, and heated to 80 ℃ and stirred at 200r/min under nitrogen atmosphere for 30min. 4g of isophorone diisocyanate and 0.001g of dibutyltin dilaurate catalyst were weighed out and added into a four-neck flask together, and the reaction was continued until the NCO of the system reached the theoretical value as determined by the di-n-butylamine method. The system was cooled to 50 ℃ and 0.5g triethylamine was added to neutralize the carboxyl groups. During the reaction, a small amount of acetone is added to reduce the viscosity of the system. Neutralization for 30min, remove the oil bath and bring the reaction to room temperature. Deionized water was added dropwise in an ice water bath and 0.44g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5h, the emulsion was transferred to a flask and the acetone was evaporated off on a rotary evaporator. An aqueous polyurethane emulsion having a solids content of about 30% was obtained and is designated DB1.

FIG. 3 is an IR spectrum of the product of example 1, which shows 771cm in the IR spectrum ^-1 The stretching vibration peak of Si-O-Si appears, and the asymmetric stretching vibration peak of Si-O-Si appears at 1132cm ^-1 And 1032cm ^-1 To (3). There was no characteristic absorption peak of the C = C double bond in the FTIR spectrum, indicating that the eugenol reaction was complete and the results were consistent with the NMR results. The infrared spectrum of the product prepared in comparative example 1 is also given in FIG. 3 for comparison.

Example 2

Steps 1 and 2 are the same as steps 1 and 2 in example 1;

and step 3: preparation of organosilicon modified waterborne polyurethane

9.00g of polyester polyol, 0.65g of 2, 2-dimethylolpropionic acid and 0.42g of eugenol diphenol (accounting for 3 percent of the content of the polyurethane prepolymer) are weighed into a 100mL four-neck flask provided with a mechanical stirring, reflux condenser and thermometer, heated to 80 ℃, and stirred for 30min at 200r/min under a nitrogen atmosphere. 4g of isophorone diisocyanate and 0.001g of dibutyltin dilaurate catalyst were weighed out and added into a four-neck flask together, and the reaction was continued until the NCO of the system reached the theoretical value as determined by the di-n-butylamine method. The system was cooled to 50 ℃ and 0.44g triethylamine was added to neutralize the carboxyl groups. During the reaction, a small amount of acetone is added to reduce the viscosity of the system. Neutralization for 30min, remove the oil bath and bring the reaction to room temperature. Deionized water was added dropwise in an ice water bath and 0.44g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5h, the emulsion was transferred to the flask and the acetone was distilled off on a rotary evaporator. An aqueous polyurethane emulsion having a solids content of about 30% was obtained and is designated WPU2.

The test shows that the WPU2 is stable after being placed at room temperature for 6 months.

Example 3

Steps 1 and 2 are the same as steps 1 and 2 in example 1;

and 3, step 3: preparation of organosilicon modified waterborne polyurethane

8.10g of polyester polyol, 0.61g of 2, 2-dimethylolpropionic acid and 0.66g of eugenol diphenol (5 percent of the content of the polyurethane prepolymer) are weighed and added into a 100mL four-neck flask provided with a mechanical stirring, reflux condenser and a thermometer, the temperature is raised to 80 ℃, and the mixture is stirred for 30min at 200r/min under the nitrogen atmosphere. 4g of isophorone diisocyanate and 0.001g of dibutyltin dilaurate catalyst are weighed and added into a four-neck flask together, and the reaction is continued until the NCO of the system reaches the theoretical value measured by a di-n-butylamine method. The system was cooled to 50 ℃ and 0.41g triethylamine was added to neutralize the carboxyl groups. During the reaction, a small amount of acetone is added to reduce the viscosity of the system. Neutralization for 30min, remove the oil bath and bring the reaction to room temperature. Deionized water was added dropwise in an ice water bath, and 0.43g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5h, the emulsion was transferred to the flask and the acetone was distilled off on a rotary evaporator. An aqueous polyurethane emulsion having a solids content of about 30% was obtained and is designated WPU3.

The test shows that the WPU3 is still stable after being placed at room temperature for 6 months.

Example 4

Steps 1 and 2 are the same as steps 1 and 2 in example 1;

and 3, step 3: preparation of organosilicon modified waterborne polyurethane

6.95g of polyester polyol, 0.55g of 2, 2-dimethylolpropionic acid and 0.95g (8% of the content of the polyurethane prepolymer) of eugenol diphenol are weighed into a 100mL four-neck flask equipped with a mechanical stirring, reflux condenser and thermometer, heated to 80 ℃ and stirred for 30min at 200r/min under a nitrogen atmosphere. 4g of isophorone diisocyanate and 0.001g of dibutyltin dilaurate catalyst were weighed out and added into a four-neck flask together, and the reaction was continued until the NCO of the system reached the theoretical value as determined by the di-n-butylamine method. The system was cooled to 50 ℃ and 0.37g triethylamine was added to neutralize the carboxyl groups. During the reaction, a small amount of acetone is added to reduce the viscosity of the system. Neutralization was carried out for 30min, the oil bath pan was removed, and the reaction was brought to room temperature. Deionized water was added dropwise in an ice water bath and 0.44g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5h, the emulsion was transferred to a flask and the acetone was evaporated off on a rotary evaporator. An aqueous polyurethane emulsion having a solids content of about 30% was obtained and is designated WPU4.

The test shows that the WPU4 is stable after being placed at room temperature for 6 months.

Example 5

Steps 1 and 2 are the same as steps 1 and 2 in example 1;

and 3, step 3: preparation of organosilicon modified waterborne polyurethane

9.00g of polyester polyol, 0.72g of 2, 2-dimethylolbutyric acid and 0.42g of eugenol diphenol (accounting for 3 percent of the content of the polyurethane prepolymer) are weighed and added into a 100mL four-neck flask provided with a mechanical stirring, reflux condenser tube and thermometer, the temperature is raised to 80 ℃, and the mixture is stirred for 30min at 200r/min under the nitrogen atmosphere. 4g of isophorone diisocyanate and 0.001g of dibutyltin dilaurate catalyst were weighed out and added into a four-neck flask together, and the reaction was continued until the NCO of the system reached the theoretical value as determined by the di-n-butylamine method. The system was cooled to 50 ℃ and 0.44g triethylamine was added to neutralize the carboxyl groups. During the reaction, a small amount of acetone is added to reduce the viscosity of the system. Neutralization for 30min, remove the oil bath and bring the reaction to room temperature. Deionized water was added dropwise in an ice water bath and 0.44g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5h, the emulsion was transferred to a flask and the acetone was evaporated off on a rotary evaporator. Obtaining the waterborne polyurethane emulsion with the solid content of about 30 percent, and marking as WPU5.

The WPU5 was tested to be stable after 6 months at room temperature.

Example 6

Steps 1 and 2 are the same as steps 1 and 2 in example 1;

and step 3: preparation of organosilicon modified waterborne polyurethane

5.00g of polyester polyol, 0.45g of 2, 2-dimethylolpropionic acid and 1.46g of eugenol diphenol (the mass ratio of the 2, 2-dimethylolpropionic acid to the eugenol diphenol is 1 to 324 percent in the content of the polyurethane prepolymer) are weighed and added into a 100mL four-neck flask provided with a mechanical stirring, reflux condenser and thermometer, the temperature is raised to 80 ℃, and the mixture is stirred for 30min at 200r/min under a nitrogen atmosphere. 4g of isophorone diisocyanate and 0.001g of dibutyltin dilaurate catalyst are weighed and added into a four-neck flask together, and the reaction is continued until the NCO of the system reaches the theoretical value measured by a di-n-butylamine method. The system was cooled to 50 ℃ and 0.31g triethylamine was added to neutralize the carboxyl groups. During the reaction, a small amount of acetone is added to reduce the viscosity of the system. Neutralization for 30min, remove the oil bath and bring the reaction to room temperature. Deionized water was added dropwise in an ice water bath, and 0.43g of ethylenediamine was added for post-chain extension. Stirring was continued for 1.5h, the emulsion was transferred to a flask and the acetone was evaporated off on a rotary evaporator. And obtaining the waterborne polyurethane emulsion with the solid content of about 30 percent, and marking the waterborne polyurethane emulsion as WPU6.

Through testing, the WPU6 is settled at the bottom after being placed for several days, the requirement of stable storage at room temperature is not met, and performance testing is not performed subsequently.

And (3) performance testing:

uniformly pouring the organic silicon modified waterborne polyurethane emulsion (or waterborne polyurethane emulsion) into a polytetrafluoroethylene mold, placing the mold at room temperature for 2 days, then placing the mold into an oven, drying the mold at the constant temperature of 40 ℃ for 48 hours, and placing the prepared latex film into a dryer for later use.

Detecting the performance of the silicon modified waterborne polyurethane film:

the tensile strength test standard is determined according to GB/T1040.3-2006 standard, the tensile strength of the membrane is tested by a universal material testing machine (model Zwick/Roell Zo 20) of Zwick Co., ltd, germany, and the average value is obtained by 5 times of tests at room temperature.

The contact angle test method is carried out according to the GB/T30447-2013 standard, the water contact angle is measured by a video optical contact angle measuring instrument (OCA 20) of Datophysics company of Germany, and the test result is the average value of five positions on a sample.

The products prepared in examples 1 to 5 and comparative example 1 were tested according to the above test methods, the results of the mechanical property test are set forth in table 1, and the water contact angle data are set forth in table 2 below.

TABLE 1

TABLE 2

From the maximum tensile strength and elongation at break of examples 1 to 5 and comparative example 1 in table 1, it can be found that the addition of eugenol-based diphenol can significantly improve the maximum tensile strength of the aqueous polyurethane film. The maximum tensile strength at the time of 3% addition can be increased to 22.4MPa, which is 3.6 times that of the non-added aqueous polyurethane film.

Comparing the data of example 2 and example 5, it can be seen that silicone waterborne polyurethanes having better water resistance and mechanical properties are obtained using 2, 2-dimethylolpropionic acid as the hydrophilic chain extender than using 2, 2-dimethylolbutyric acid.

Example 6 illustrates that the storage stability of emulsions prepared when the mass ratio of 2, 2-dimethylolpropionic acid to eugenol-diphenol is not properly selected is greatly reduced.

As can be seen from a comparison of the data in Table 2, the water resistance of the product prepared by adding eugenol-based diphenol is better than that of the non-aqueous polyurethane prepared in comparative example 1. The above data demonstrate that the silicone modified waterborne polyurethane prepared by the method disclosed herein has better tensile strength and water resistance.

Claims (8)

1. A preparation method of organosilicon modified waterborne polyurethane is characterized by comprising the following steps:

(1) Eugenol and 1, 3-tetramethyl disiloxane are taken as raw materials, and eugenol diphenol is synthesized by hydrosilylation reaction;

(2) Diisocyanate, polyester polyol, the eugenol diphenol prepared in the step (1) and a polyhydroxy hydrophilic chain extender are used as raw materials, and after polymerization reaction, the raw materials and an alkaline neutralizing agent are subjected to neutralization reaction to obtain a waterborne polyurethane prepolymer;

the polyhydroxy hydrophilic chain extender is selected from 2, 2-dimethylolpropionic acid;

the mass ratio of diisocyanate, polyester polyol, eugenol diphenol to polyhydroxy hydrophilic chain extender is 1: (173.75-250)%: (3.75-23.75)%: (13.75-18)%;

the mass ratio of the polyhydroxy hydrophilic chain extender to the eugenol diphenol is 1:

(55～65)％；

the mass of the eugenol diphenol accounts for 3 percent of the total mass of the diisocyanate, the polyester polyol, the eugenol diphenol, the polyhydroxy hydrophilic chain extender and the alkaline neutralizer;

(3) And mixing the aqueous polyurethane prepolymer, water and a post-chain extender, and carrying out chain extension reaction to obtain the organic silicon modified aqueous polyurethane.

2. The method for preparing the silicone-modified aqueous polyurethane according to claim 1, wherein in step (1):

the molar ratio of the eugenol to the 1, 3-tetramethyldisiloxane is 1: (50-100)%;

the temperature of the hydrosilylation reaction is 55-70 ℃, and the reaction time is 24-48 h.

3. The method for preparing the silicone-modified aqueous polyurethane according to claim 1, wherein in step (2):

the diisocyanate is selected from one or more of 2, 4-toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate and 1, 6-hexamethylene diisocyanate;

the polyester polyol is selected from polyethylene adipate-1, 4-butanediol glycol.

4. The method for preparing the organosilicon-modified waterborne polyurethane according to claim 3, wherein:

the polyester polyol is prepared by taking adipic acid, ethylene glycol and 1, 4-butanediol as raw materials through esterification reaction;

the mass ratio of adipic acid, ethylene glycol and 1, 4-butanediol is 1:24.9%:36.2 percent.

5. The method for preparing organosilicon modified waterborne polyurethane according to claim 1, wherein in the step (2), the polymerization reaction temperature is 75-85 ℃ and the reaction time is 2-3 h.

6. The method for preparing the silicone-modified aqueous polyurethane according to claim 1, wherein in step (2):

the alkaline neutralizing agent is selected from one or more of triethylamine, ammonia water, sodium hydroxide and potassium hydroxide;

the molar ratio of the alkaline neutralizing agent to the polyhydroxy hydrophilic chain extender is 0.8-1.1: 1;

the temperature of the neutralization reaction is 45-55 ℃, and the time is 20-40 min.

7. The method for preparing the silicone-modified aqueous polyurethane according to claim 1, wherein in step (3):

the post chain extender is one or more selected from ethylenediamine, 1, 4-butanediamine and hydrazine hydrate;

the mass ratio of the diisocyanate to the rear chain extender is 1: (10-15)%;

the temperature of the post chain extension reaction is 5-15 ℃, and the time is 1-2 h.

8. An organosilicon modified waterborne polyurethane prepared by the method of any one of claims 1 to 7.

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