Waterproof polyester polyol containing silicon-fluorine long-chain cross-linking body as well as preparation method and application of waterproof polyester polyol

Abstract

The invention belongs to the technical field of polyester polyol, and particularly relates to waterproof polyester polyol containing a silicon-fluorine long-chain cross-linking body as well as a preparation method and application of the waterproof polyester polyol. Comprising the following steps: (1) mixing adipic acid and pentaerythritol for esterification reaction to obtain basic polyester polyol; hydroxyl-terminated fluorine-containing polysiloxane is added into the basic polyester polyol for continuous reaction, and modified polyester polyol is prepared; (2) dispersing nano silicon dioxide in an alcohol solvent, then dispersing 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane in deionized water, and carrying out a mixed reaction so as to prepare modified nano silicon dioxide; and (3) adding the modified nano silicon dioxide into the modified polyester polyol, and reacting to obtain the waterproof polyester polyol containing the silicon-fluorine long-chain crosslinking body. The waterproof performance of the material is enhanced by introducing a silicon-fluorine long chain into a polyester polyol structure, and the roughness of the surface of the material is improved by introducing nano silicon dioxide, so that the hydrophobicity is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester polyols, and in particular relates to waterproof polyester polyols containing silicon-fluorine long-chain crosslinks and a preparation method and application thereof. Background Art

[0002] As a key raw material for synthesizing polymer materials such as polyurethane and polyurea, polyester polyols have always played an important role in the field of waterproof materials. However, traditional polyester polyols have certain limitations in waterproof performance, especially when used in extreme environmental conditions (such as strong acid, strong alkali, high temperature or high humidity environment), their waterproof effect and durability are often difficult to meet the expected requirements. In order to overcome this challenge, researchers are constantly exploring new modification methods to improve the waterproof performance of polyester polyols.

[0003] Silicon-fluorine segments, with their unique low surface energy, excellent hydrophobicity and outstanding chemical resistance, have shown wide application potential in the fields of waterproofing, oil resistance and antifouling. By introducing silicon-fluorine segments into polyester polyols and through specific chemical reactions, waterproof polyester polyols containing silicon-fluorine long-chain crosslinks can be prepared. This new material not only inherits the advantages of traditional polyester polyols, such as good processing performance and certain mechanical strength, but also significantly enhances its waterproof performance and weather resistance, bringing new breakthroughs in the field of waterproof materials.

[0004] However, although waterproof polyester polyols containing long-chain crosslinks of silicon and fluorine have many advantages, their preparation methods are still facing some technical difficulties. For example, precise control of reaction conditions is crucial to ensure the quality and performance of the product, but it is often difficult to achieve the ideal state in actual operation. In addition, although the introduction of nanomaterials provides a new way to improve the performance of polyester polyols, directly adding nano-silicon dioxide to polyester polyols often leads to agglomeration due to the strong interaction between nanoparticles, making the dispersion of nano-silicon dioxide in polyester polyols uneven, thereby affecting the improvement of waterproof effect. Therefore, it is of great significance to develop a new method for preparing polyester polyols to meet the growing demand for high-performance polyester polyols in the field of waterproof materials. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain cross-linked body. By precisely controlling the reaction conditions, the silicon-fluorine long chain is successfully introduced into the polyester polyol structure, thereby enhancing the waterproof performance of the material. The roughness of the material surface is increased by the introduction of nano-silicon dioxide, thereby further improving the hydrophobicity.

[0006] Another object of the present invention is to provide a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinker and its application.

[0007] The technical solution adopted by the present invention is as follows: The method for preparing the waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body comprises the following steps: (1) Add adipic acid and pentaerythritol to a pressure-resistant reactor, then add an esterification catalyst, control the oxygen content in the reactor to be less than 50 ppm, evacuate to -0.09~-0.093 MPa, raise the temperature to 190~210°C to start the esterification reaction, evaporate the generated water, and keep the temperature to react until the acid value is less than 30 mgKOH / g to obtain a basic polyester polyol; add terminal hydroxyl fluorinated polysiloxane to the basic polyester polyol, continue the reaction at 200~230°C until the acid value is less than 30 mgKOH / g to obtain a modified polyester polyol; (2) dispersing nano-silica in an alcohol solvent to obtain a nano-silica dispersion; then mixing 1H,1H,2H,2H-perfluorooctyltriethoxysilane with deionized water, adjusting the pH to 8-12 with ammonia water, and then adding the nano-silica dispersion, reacting at 50-70° C. for 25-30 hours, and after the reaction is completed, centrifuging, washing, and drying to obtain modified nano-silica; (3) Adding modified nano-silica to modified polyester polyol, reacting at 140-160°C for 3-4 hours, to obtain waterproof polyester polyol containing silicon-fluorine long-chain crosslinks.

[0008] In the step (1), the number average molecular weight of the base polyester polyol is 2000-3000; the viscosity of the terminal hydroxyl fluorinated polysiloxane is 1000 cps and the functionality is 2, which is purchased from Shanghai Silicon Mountain Polymer Materials Co., Ltd.

[0009] In the step (1), the molar ratio of adipic acid to pentaerythritol is (1-1.2):1; the amount of terminal hydroxyl fluorinated polysiloxane is 5-15 wt.% of the total amount of adipic acid, pentaerythritol and terminal hydroxyl fluorinated polysiloxane.

[0010] In the step (1), the esterification catalyst is tetrabutyl titanate, and the amount of the esterification catalyst used is 0.1 wt.% of the total amount of adipic acid and pentaerythritol.

[0011] In the step (2), the alcohol solvent is one of methanol, ethanol or isopropanol.

[0012] In the step (2), the mass ratio of nano-silicon dioxide to alcohol solvent is 1:(5-10); the mass ratio of 1H,1H,2H,2H-perfluorooctyltriethoxysilane to deionized water is 1:(3-5).

[0013] In the step (2), the amount of 1H,1H,2H,2H-perfluorooctyltriethoxysilane used is 10-15wt.% of the total amount of nano-silicon dioxide.

[0014] In the step (3), the amount of modified nano-silicon dioxide used is 5-20wt.% of the total amount of modified polyester polyol.

[0015] The waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body is prepared by the preparation method of the waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body.

[0016] The waterproof polyester polyol containing silicon-fluorine long-chain crosslinking body is used for preparing waterproof coating.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The preparation method of the waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body of the present invention significantly enhances the waterproof performance of the polyester polyol by introducing terminal hydroxyl fluorine-containing polysiloxane and modified nano-silicon dioxide. The modified nano-silicon dioxide not only increases the roughness of the material surface, further improves the hydrophobicity, but also avoids the agglomeration phenomenon. At the same time, the introduced -CF3 group with low surface free energy effectively enhances the waterproof effect. The prepared waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body has excellent waterproof performance and stability, and has broad application prospects in the field of waterproof materials. DETAILED DESCRIPTION

[0018] The present invention is further described below with reference to the embodiments, but they do not limit the implementation of the present invention.

[0019] The raw materials used in the examples and comparative examples are conventional commercially available raw materials unless otherwise specified, and the process methods used in the examples and comparative examples are conventional methods in the art unless otherwise specified.

[0020] Example 1 The preparation method of the waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body comprises the following steps: (1) Add 800g of adipic acid and 738g of pentaerythritol to a pressure-resistant reactor, and then add 1.54g of tetrabutyl titanate. Control the oxygen content in the reactor to 10ppm, evacuate to -0.09MPa, raise the temperature to 190°C to start the esterification reaction, maintain the reaction temperature, evaporate the generated water, and continue the reaction until the acid value is 20mgKOH / g to obtain a basic polyester polyol with a number average molecular weight of 2800g / mol. Add 82g of terminal hydroxyl fluorinated polysiloxane to the basic polyester polyol, and continue the reaction at 200°C until the acid value is 23mgKOH / g to obtain a modified polyester polyol; (2) Disperse 20g of nano-silica in 100g of methanol to obtain a nano-silica dispersion. Then mix 2g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane with 6g of deionized water, adjust the pH to 8 with ammonia water, then add the nano-silica dispersion, and react at 50°C for 30h. After the reaction is completed, centrifuge, wash, and dry to obtain modified nano-silica; (3) Add 15 g of modified nano-silica to 300 g of modified polyester polyol and react at 140 °C for 4 h to obtain a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinker.

[0021] Example 2 The preparation method of the waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body comprises the following steps: (1) Add 1130g of adipic acid and 886g of pentaerythritol to a pressure-resistant reactor, and then add 2g of tetrabutyl titanate. Control the oxygen content in the reactor to 45ppm, evacuate to -0.093MPa, raise the temperature to 210°C to start the esterification reaction, maintain the reaction temperature, evaporate the generated water, and continue the reaction until the acid value is 28mgKOH / g to obtain a basic polyester polyol with a number average molecular weight of 2000g / mol. Add 350g of terminal hydroxyl fluorinated polysiloxane to the basic polyester polyol, and continue the reaction at 230°C until the acid value is 27mgKOH / g to obtain a modified polyester polyol; (2) Disperse 13g of nano-silica in 130g of ethanol to obtain a nano-silica dispersion. Then mix 2g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane with 10g of deionized water, adjust the pH to 12 with ammonia water, then add the nano-silica dispersion, and react at 70°C for 25h. After the reaction is completed, centrifuge, wash, and dry to obtain modified nano-silica; (3) Add 10 g of modified nano-silica to 100 g of modified polyester polyol and react at 160 °C for 3 h to obtain a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinker.

[0022] Example 3 The preparation method of the waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body comprises the following steps: (1) Add 960g of adipic acid and 812g of pentaerythritol to a pressure-resistant reactor, then add 1.8g of tetrabutyl titanate, control the oxygen content in the reactor to 30ppm, evacuate to an intermediate value of -0.092MPa, raise the temperature to 205°C to start the esterification reaction, maintain the reaction temperature, evaporate the generated water, and continue the reaction until the acid value is 25mgKOH / g to obtain a basic polyester polyol with a number average molecular weight of 2250g / mol. Add 200g of terminal hydroxyl fluorinated polysiloxane to the basic polyester polyol, and continue the reaction at 215°C until the acid value is 26mgKOH / g to obtain a modified polyester polyol; (2) Disperse 15g of nano-silica in 120g of isopropanol to obtain a nano-silica dispersion. Then mix 2g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane with 8g of deionized water, adjust the pH to 10 with ammonia water, then add the nano-silica dispersion, and react at 65°C for 28h. After the reaction is completed, centrifuge, wash, and dry to obtain modified nano-silica. (3) Add 13 g of modified nano-silica to 80 g of modified polyester polyol and react at 150 °C for 3.5 h to obtain a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinker.

[0023] Comparative Example 1 The difference from Example 1 is that after the basic polyester polyol is prepared in step (1), modified nano-silicon dioxide is added to the basic polyester polyol in step (3) to prepare the waterproof polyester polyol. The rest is the same as Example 1.

[0024] Comparative Example 2 The difference from Example 1 is that in step (2), an equal amount of γ-methacryloxypropyltrimethoxysilane is used to replace 1H,1H,2H,2H-perfluorooctyltriethoxysilane, and the rest is the same as Example 1.

[0025] Comparative Example 3 The difference from Example 1 is that 2 g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane is mixed with 8 g of deionized water, added to 80 g of the modified polyester polyol prepared in step (1), and reacted at 200° C. for 3.5 h. The rest is the same as Example 1.

[0026] With reference to GB / T30693-2014, the contact angles (°) of the waterproof polyester polyols prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested.

[0027] The test results are shown in Table 1.

[0028] Table 1 Performance test results

[0029] As can be seen from Table 1, in Examples 1 to 3, by adding terminal hydroxyl fluorinated polysiloxane during the preparation of polyester polyol, silicon and fluorine elements were successfully introduced into the molecular chain of polyester polyol, effectively reducing the surface energy of the material and improving its hydrophobicity. At the same time, the introduction of perfluorooctyl triethoxysilane formed a low surface energy -CF3 structure on the surface of the material, further enhancing the hydrophobicity. In addition, the addition of modified nano-silica can increase the roughness of the material surface, further enhancing the hydrophobic effect of the material.

[0030] Compared with Example 1, since the terminal hydroxyl fluorinated polysiloxane is not introduced into the main chain of the molecule in Comparative Example 1, the silicon and fluorine contents of the finally prepared waterproof polyester polyol are relatively low, and the hydrophobicity is reduced.

[0031] Compared with Example 1, in Comparative Example 2, since the low surface energy -CF3 structure is not introduced into the molecular structure, the hydrophobicity of the obtained waterproof polyester polyol is significantly reduced.

[0032] Compared with Example 1, since nano-silicon dioxide is not added in Comparative Example 3, the surface roughness of the prepared waterproof polyester polyol is lower, which leads to a decrease in the hydrophobicity of the prepared waterproof polyester polyol.

Claims

1. A method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body, characterized in that: The following steps are involved: (1) Adipic acid and pentaerythritol are mixed and subjected to an esterification reaction under the action of an esterification catalyst to obtain a basic polyester polyol; terminal hydroxyl-containing fluorinated polysiloxane is added to the basic polyester polyol to continue the reaction to obtain a modified polyester polyol; (2) dispersing nano-silica in an alcohol solvent to obtain a nano-silica dispersion; then mixing 1H,1H,2H,2H-perfluorooctyltriethoxysilane with deionized water, adjusting the pH to 8-12, and then adding the nano-silica dispersion to react to obtain modified nano-silica; (3) Adding modified nano-silica to modified polyester polyol for reaction to obtain waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body; wherein the amount of modified nano-silica is 5-20wt.% of the total amount of modified polyester polyol.

2. The method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body according to claim 1, characterized in that: In the step (1), the number average molecular weight of the base polyester polyol is 2000-3000; and the viscosity of the terminal hydroxyl fluorinated polysiloxane is 1000 cps.

3. The method for preparing the waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body according to claim 1, characterized in that: In the step (1), the molar ratio of adipic acid to pentaerythritol is (1-1.2):1; the amount of terminal hydroxyl fluorinated polysiloxane is 5-15 wt.% of the total amount of adipic acid, pentaerythritol and terminal hydroxyl fluorinated polysiloxane.

4. The method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body according to claim 1, characterized in that: In the step (1), the esterification catalyst is tetrabutyl titanate; the temperature of the esterification reaction is 190-210°C; and the temperature of the reaction after adding the terminal hydroxyl fluorinated polysiloxane is 200-230°C.

5. The method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body according to claim 1, characterized in that: In the step (2), the alcohol solvent is one of methanol, ethanol or isopropanol.

6. The method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body according to claim 1, characterized in that: In the step (2), the mass ratio of nano-silicon dioxide to alcohol solvent is 1:(5-10); the mass ratio of 1H,1H,2H,2H-perfluorooctyltriethoxysilane to deionized water is 1:(3-5).

7. The method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body according to claim 1, characterized in that: In the step (2), the amount of 1H,1H,2H,2H-perfluorooctyltriethoxysilane is 10-15wt.% of the total amount of nano-silicon dioxide; and the reaction temperature is 50-70°C.

8. The method for preparing a waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body according to claim 1, characterized in that: In the step (3), the reaction temperature is 140-160°C.

9. A waterproof polyester polyol containing a silicon-fluorine long-chain crosslinked body, characterized in that: The waterproof polyester polyol is prepared by the preparation method of the silicon-fluorine-containing long-chain cross-linked body according to any one of claims 1 to 8.

10. The use of the waterproof polyester polyol containing silicon-fluorine long-chain crosslinked body according to claim 9, characterized in that: Used to prepare waterproof coatings.

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