Silane coupling agent modified chain extender, single-component polyurethane pouring sealant and preparation method of single-component polyurethane pouring sealant
By combining silane coupling agent-modified chain extender with polyurethane potting compound, the defects of polyurethane potting compound in terms of moisture and heat resistance and adhesive strength are solved, enabling wider application.
Patent Information
- Application Number
- CN202510949621.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-10
- Publication Date
- 2025-11-21
AI Technical Summary
Existing polyurethane potting compounds have shortcomings in terms of adhesive strength, resistance to damp heat, and long-term stability, which limit their application in harsh environments.
A chain extender modified with a silane coupling agent was prepared by combining an aminopropyl silane coupling agent, a diisocyanate, and a trifunctional chain extender. This modified chain extender was then combined with other components in a polyurethane potting compound to form a one-component polyurethane potting compound.
It improves the hygrothermal stability and compatibility with thermally conductive fillers of polyurethane potting compound, while enhancing the adhesion strength between the adhesive and the substrate, thus expanding its application range.
Smart Images
Figure CN120988232A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a modified chain extender and a one-component polyurethane potting compound and its preparation method, belonging to the field of polyurethane adhesive preparation technology. Background Technology
[0002] Polyurethane potting compounds are key encapsulation materials for electronic devices and power batteries in new energy vehicles, and their performance directly affects the safety and lifespan of electronic components or battery systems. Currently, the mainstream potting compounds on the market mainly include three categories: polyurethane, silicone, and epoxy resin. Among them, polyurethane potting compounds are widely used due to their combination of good adhesive strength and toughness. However, traditional polyurethane potting compounds have shortcomings in adhesive strength, resistance to damp heat, and long-term stability, severely limiting their reliability in harsh environments and their application areas.
[0003] To overcome these shortcomings, researchers have attempted various modification methods, but all have significant limitations: While directly adding silane coupling agents (such as 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane) to the polyurethane system can improve interfacial bonding, the effect is limited and prone to side effects. The active hydrogen in primary amino silanes reacts rapidly with isocyanates (-NCO), leading to increased prepolymer viscosity and even gelation. Using silane coupling agents without primary amine groups causes them to migrate to the surface, resulting in decreased bulk properties. Existing chain extenders (such as ethylene glycol, trimethylolpropane, and 2-amino-1,3-propanediol, etc., small molecule alcohols or amines) can modulate the microstructure of hard segments, but still have drawbacks. Traditional chain extenders only provide rigid segments and cannot simultaneously introduce moisture-curing groups and adhesion-promoting groups. Existing silane-modified polyurethane technologies mostly focus on single performance optimization and lack systematic solutions.
[0004] Therefore, developing a silane coupling agent modified chain extender that can improve the adhesion and durability of polyurethane potting compounds without affecting the application difficulty of the potting compounds has important application value and broad market prospects. Summary of the Invention
[0005] To address the problem that existing silane-modified polyurethane technologies often focus on optimizing single performance aspects and lack systematic solutions, this invention proposes a silane coupling agent-modified chain extender, a one-component polyurethane potting compound, and its preparation method.
[0006] The technical solution adopted by the present invention to solve the above problems is as follows: The silane coupling agent modified chain extender of the present invention is composed of aminopropyl silane coupling agent, diisocyanate, trifunctional chain extender and solvent; the mass fraction of aminopropyl silane coupling agent is 17.9~22.1 parts, the mass fraction of diisocyanate is 16.8~26.2 parts, the mass fraction of trifunctional chain extender is 9.1~13.4 parts, and the mass fraction of solvent is 219~302 parts.
[0007] Furthermore, the aminopropylsilane coupling agent is one or both of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.
[0008] Furthermore, the diisocyanate is composed of one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and phenyldimethyl diisocyanate.
[0009] Furthermore, the trifunctional chain extender is one or both of trimethylolpropane and 2-amino-1,3-propanediol.
[0010] Furthermore, the solvent is composed of one or more of ethyl acetate, acetone, dimethyl sulfoxide, and N,N-dimethylformamide.
[0011] The preparation method of the silane coupling agent modified chain extender of the present invention includes the following steps: Step 1: Weigh diisocyanate and part of the solvent into the reactor, set the reaction temperature and stirring speed to ensure that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh the aminopropylsilane coupling agent and solvent into a constant pressure dropping funnel, and slowly drop them into the reactor to carry out the first step of the reaction. The reaction time is 2.5~3 h to obtain the intermediate product. Step 3: Weigh the trifunctional chain extender and part of the solvent into the reactor, and slowly add the intermediate product obtained in step 2 into the reaction vessel. After all the product has been added, keep the temperature for 1.5 to 2 hours. Step 4: Distill the reaction product obtained in step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
[0012] Furthermore, the stirring rate was 150-200 r / min, the reaction temperature was 25-35 ℃, and the dropping rate was 60-80 drops / min.
[0013] The single-component polyurethane potting compound of the present invention is composed of poly(1,4-butanediol adipate), diphenylmethane diisocyanate, polyphenylmethylene polyisocyanate, alumina, silane coupling agent, chain extender, aldehyde imine latent curing agent, and organotin catalyst.
[0014] Furthermore, the mass fraction of poly(1,4-butanediol adipate) is 30-40 parts, the mass fraction of diphenylmethane diisocyanate is 10-15 parts, the mass fraction of polyphenylmethylene polyisocyanate is 8-13 parts, the mass fraction of alumina is 3-10 parts, the mass fraction of silane coupling agent modified chain extender is 1-5 parts, the mass fraction of aldehyde imine latent curing agent is 5-10 parts, and the mass fraction of organotin catalyst is 0-0.1 parts.
[0015] The preparation method of the one-component polyurethane potting compound of the present invention includes the following steps: Step 1: Weigh poly(1,4-butanediol adipate) and alumina into a reactor, disperse them by high-speed stirring, and heat to 120°C to remove water under vacuum for 2-3 hours; Step 2: Cool down to 70~80℃, turn on nitrogen gas, add diphenylmethane diisocyanate, polyphenylmethylene polyisocyanate and organotin catalyst, and keep the reaction at this temperature for 2~3 hours. Step 3: Add aldehyde-imide latent curing agent and silane coupling agent modified chain extender to the system, and continue to keep warm and stir for 0.5~1 h to obtain a one-component polyurethane potting compound.
[0016] The beneficial effects of this invention are as follows: This invention provides a method for preparing a silane coupling agent modified chain extender, which combines the silane coupling agent and the chain extender through a chemical reaction. Applying this silane coupling agent modified chain extender to a polyurethane potting compound system not only modulates the hard segment micro-regions to improve the potting compound's resistance to damp heat, but also enhances the compatibility between the polyurethane adhesive and the thermally conductive filler, while simultaneously improving the bond strength between the adhesive and the substrate. The application of the silane coupling agent modified chain extender enables polyurethane potting compounds to be used stably for extended periods in more complex environments, expanding their application range. Attached Figure Description
[0017] Figure 1 This is the infrared spectrum of the intermediate product of the silane coupling agent modified chain extender in Example 1; Figure 2 This is the infrared spectrum of the silane coupling agent modified chain extender in Example 1.
[0018] Example Example 1 Example 1 This embodiment provides a method for preparing a silane coupling agent-modified chain extender and using it in polyurethane potting compounds. The specific steps are as follows: Step 1: Weigh 22.2 parts of isophorone diisocyanate and 120 parts of ethyl acetate into the reactor, set the reaction temperature to 25℃ and the stirring speed to 160 r / min, so that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh 17.9 parts of 3-aminopropyltrimethoxysilane and 100 parts of ethyl acetate into a constant pressure dropping funnel, and slowly add them to the reactor at a dropping rate of 60-80 drops / minute to carry out the first step reaction. The reaction time is 2.5-3 hours to obtain the intermediate product. After the reaction is completed, the product is discharged for later use. Step 3: Weigh 9.1 parts of 2-amino-1,3-propanediol and 110 parts of ethyl acetate into the reactor. Add the intermediate product obtained in Step 2 into the reaction vessel at a dropping rate of 60-80 drops / minute. After all the product has been added, keep the reaction at the temperature for 1.5-2 hours. Step 4: Distill the reaction product obtained in Step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
[0019] Step 5: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2-3 hours; cool to 70-80℃, turn on nitrogen, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2-3 hours; add 5 parts of latent curing agent and 3 parts of the above-mentioned silane coupling agent modified chain extender to the system, and continue to keep the reaction at this temperature for 0.5-1 hours to obtain a one-component polyurethane potting compound.
[0020] Example 2 This embodiment provides a method for preparing a silane coupling agent-modified chain extender and using it in polyurethane potting compounds. The specific steps are as follows: Step 1: Weigh 26.2 parts of dicyclohexylmethane-4,4'-diisocyanate and 125 parts of ethyl acetate into a reactor. Set the reaction temperature to 25℃ and the stirring speed to 160 r / min to ensure that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh 22.1 parts of 3-aminopropyltriethoxysilane and 110 parts of ethyl acetate into a constant pressure dropping funnel, and slowly add them to the reactor at a dropping rate of 60-80 drops / minute to carry out the first step reaction. The reaction time is 2.5-3 hours to obtain the intermediate product. After the reaction is completed, the product is discharged for later use. Step 3: Weigh 13.4 parts of trimethylolpropane and 160 parts of ethyl acetate into the reactor. Add the intermediate product obtained in Step 2 into the reaction vessel at a dropping rate of 60-80 drops / minute. After all the product has been added, keep the reaction at the temperature for 1.5-2 hours. Step 4: Distill the reaction product obtained in Step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
[0021] Step 5: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2-3 hours; cool to 70-80℃, turn on nitrogen, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2-3 hours; add 5 parts of latent curing agent and 3 parts of the above-mentioned silane coupling agent modified chain extender to the system, and continue to keep the reaction at this temperature for 0.5-1 hours to obtain a one-component polyurethane potting compound.
[0022] Example 3 This embodiment provides a method for preparing a silane coupling agent-modified chain extender and using it in polyurethane potting compounds. The specific steps are as follows: Step 1: Weigh 16.8 parts of hexamethylene diisocyanate and 120 parts of dimethyl sulfoxide into a reactor, set the reaction temperature to 25℃ and the stirring speed to 160 r / min, so that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh 17.9 parts of 3-aminopropyltrimethoxysilane and 100 parts of dimethyl sulfoxide into a constant pressure dropping funnel, and slowly add them to the reactor at a dropping rate of 60-80 drops / minute to carry out the first step reaction. The reaction time is 2.5-3 hours to obtain the intermediate product. After the reaction is completed, discharge the product for later use. Step 3: Weigh 9.1 parts of 2-amino-1,3-propanediol and 110 parts of dimethyl sulfoxide into the reactor. Add the intermediate product obtained in Step 2 into the reaction vessel at a dropping rate of 60-80 drops / minute. After all the product has been added, keep the reaction at the temperature for 1.5-2 hours. Step 4: Distill the reaction product obtained in Step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
[0023] Step 5: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen gas, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent and 1 part of the above-mentioned silane coupling agent modified chain extender to the system, and continue to keep the reaction at this temperature for 0.5 h to obtain a one-component polyurethane potting compound.
[0024] Example 4 This embodiment provides a method for preparing a silane coupling agent-modified chain extender and using it in polyurethane potting compounds. The specific steps are as follows: Step 1: Weigh 18.8 parts of m-phenylenedimethyl isocyanate and 110 parts of N,N-dimethylformamide into a reactor, set the reaction temperature to 25℃ and the stirring speed to 160 r / min, so that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh 17.9 parts of 3-aminopropyltrimethoxysilane and 100 parts of N,N-dimethylformamide into a constant pressure dropping funnel, and slowly add them to the reactor at a dropping rate of 60-80 drops / minute to carry out the first step reaction. The reaction time is 2.5-3 hours to obtain the intermediate product. After the reaction is completed, discharge the product for later use. Step 3: Weigh 9.1 parts of 2-amino-1,3-propanediol and 120 parts of N,N-dimethylformamide into a reactor. Add the intermediate product obtained in Step 2 into the reaction vessel at a dropping rate of 60-80 drops / minute. After all the product has been added, keep the reaction at the temperature for 1.5-2 hours. Step 4: Distill the reaction product obtained in Step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
[0025] Step 5: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent and 5 parts of the above-mentioned silane coupling agent modified chain extender to the system, and continue to keep the mixture at this temperature and stir for 0.5 h to obtain a one-component polyurethane potting compound.
[0026] Example 5 This embodiment provides a method for preparing a silane coupling agent-modified chain extender and using it in polyurethane potting compounds. The specific steps are as follows: Step 1: Weigh 16.8 parts of hexamethylene diisocyanate and 120 parts of dimethyl sulfoxide into a reactor, set the reaction temperature to 25℃ and the stirring speed to 160 r / min, so that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh 17.9 parts of 3-aminopropyltrimethoxysilane and 100 parts of dimethyl sulfoxide into a constant pressure dropping funnel, and slowly add them to the reactor at a dropping rate of 60-80 drops / minute to carry out the first step reaction. The reaction time is 2.5-3 hours to obtain the intermediate product. After the reaction is completed, discharge the product for later use. Step 3: Weigh 13.4 parts of trimethylolpropane and 110 parts of dimethyl sulfoxide into the reactor. Add the intermediate product obtained in Step 2 into the reaction vessel at a dropping rate of 60-80 drops / minute. After all the product has been added, keep the reaction at the temperature for 1.5-2 hours. Step 4: Distill the reaction product obtained in Step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
[0027] Step 5: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen gas, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent and 1 part of the above-mentioned silane coupling agent modified chain extender to the system, and continue to keep the reaction at this temperature for 0.5 h to obtain a one-component polyurethane potting compound.
[0028] Example 6 This embodiment provides a method for preparing a silane coupling agent-modified chain extender and using it in polyurethane potting compounds. The specific steps are as follows: Step 1: Weigh 16.8 parts of hexamethylene diisocyanate and 120 parts of dimethyl sulfoxide into a reactor, set the reaction temperature to 25℃ and the stirring speed to 160 r / min, so that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh 17.9 parts of 3-aminopropyltrimethoxysilane and 100 parts of dimethyl sulfoxide into a constant pressure dropping funnel, and slowly add them to the reactor at a dropping rate of 60-80 drops / minute to carry out the first step reaction. The reaction time is 2.5-3 hours to obtain the intermediate product. After the reaction is completed, discharge the product for later use. Step 3: Weigh 13.4 parts of trimethylolpropane and 110 parts of dimethyl sulfoxide into the reactor. Add the intermediate product obtained in Step 2 into the reaction vessel at a dropping rate of 60-80 drops / minute. After all the product has been added, keep the reaction at the temperature for 1.5-2 hours. Step 4: Distill the reaction product obtained in Step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
[0029] Step 5: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent and 5 parts of the above-mentioned silane coupling agent modified chain extender to the system, and continue to keep the mixture at this temperature and stir for 0.5 h to obtain a one-component polyurethane potting compound.
[0030] Comparative Example 1 This comparative example provides a method for preparing polyurethane potting compound, the specific steps of which are as follows: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen gas, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent to the system, and continue to keep the mixture at this temperature and stir for 0.5 h to obtain a one-component polyurethane potting compound.
[0031] Comparative Example 2 This comparative example provides a method for preparing polyurethane potting compound, the specific steps of which are as follows: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse them by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen gas, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent and 3 parts of trimethylolpropane chain extender to the system, and continue to keep the mixture at this temperature and stir for 0.5 h to obtain a one-component polyurethane potting compound.
[0032] Comparative Example 3 This comparative example provides a method for preparing polyurethane potting compound, the specific steps of which are as follows: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent and 3 parts of 3-aminopropyltrimethoxysilane coupling agent to the system, and continue to keep the mixture at this temperature and stir for 0.5 h to obtain a one-component polyurethane potting compound.
[0033] Comparative Example 4 This comparative example provides a method for preparing polyurethane potting compound, the specific steps of which are as follows: Weigh 40 parts of poly(1,4-butanediol adipate) and 10 parts of alumina into a reactor, disperse by high-speed stirring, heat to 120℃ and remove water under vacuum for 2.5 h; cool to 70~80℃, turn on nitrogen, add 15 parts of diphenylmethane diisocyanate, 8 parts of polyphenylmethylene polyisocyanate and 0.01 parts of catalyst, and keep the reaction at this temperature for 2 h; add 5 parts of latent curing agent, 1.5 parts of 3-aminopropyltrimethoxysilane coupling agent and 1.5 parts of 2-amino-1,3-propylene glycol to the system, and continue to keep the reaction at this temperature for 0.5 h to obtain a one-component polyurethane potting compound.
[0034] Shear tests were performed on Al-Al and PET-PET bonding samples 1-6 and 1-4 after complete curing, respectively. The results are shown in the table below:
[0035] After curing at room temperature for 7 days, the shear strength was tested according to GB / T7124-2008.
[0036] The table above shows that the addition of silane coupling agent modified chain extender significantly improves the adhesion strength of the one-component polyurethane potting compound to the substrate.
[0037] After undergoing acid and alkali resistance aging and double 85 aging for 1000 hours, Examples 1-6 and Comparative Examples 1-4 were subjected to Al-Al bond shear strength tests. The results are shown in the table below:
[0038] After curing at room temperature for 7 days, acid and alkali resistance tests were performed, and after aging at double 85 for 1000 hours, shear strength tests were performed according to GB / T7124-2008.
[0039] The test results above show that the prepared silane coupling agent modified chain extender has a significant effect on improving the adhesion, acid and alkali resistance, and damp heat aging resistance of one-component polyurethane potting compounds. This invention is the first to prepare a novel silane coupling agent modified chain extender and apply it to a one-component polyurethane potting compound system, resulting in a potting compound that can meet the requirements of complex environments.
[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.
Claims
1. A silane coupling agent modified chain extender, characterized in that, The silane coupling agent modified chain extender is composed of an aminopropyl silane coupling agent, a diisocyanate, a trifunctional chain extender, and a solvent; the mass fraction of the aminopropyl silane coupling agent is 17.9~22.1 parts, the mass fraction of the diisocyanate is 16.8~26.2 parts, the mass fraction of the trifunctional chain extender is 9.1~13.4 parts, and the mass fraction of the solvent is 219~302 parts.
2. The silane coupling agent modified chain extender according to claim 1, characterized in that, The aminopropylsilane coupling agent is one or both of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.
3. The silane coupling agent modified chain extender according to claim 1, characterized in that, Diisocyanates are composed of one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and phenyldimethyl diisocyanate.
4. The silane coupling agent modified chain extender according to claim 1, characterized in that, The trifunctional chain extender is one or both of trimethylolpropane and 2-amino-1,3-propanediol.
5. The silane coupling agent modified chain extender according to claim 1, characterized in that, The solvent is composed of one or more of ethyl acetate, acetone, dimethyl sulfoxide, and N,N-dimethylformamide.
6. A method for preparing a silane coupling agent modified chain extender, characterized in that, The specific steps include: Step 1: Weigh diisocyanate and part of the solvent into the reactor, set the reaction temperature and stirring speed to ensure that the diisocyanate is evenly dispersed in the solvent and the temperature is kept constant. Step 2: Weigh the aminopropylsilane coupling agent and solvent into a constant pressure dropping funnel, and slowly drop them into the reactor to carry out the first step of the reaction. The reaction time is 2.5~3 h to obtain the intermediate product. Step 3: Weigh the trifunctional chain extender and part of the solvent into the reactor, and slowly add the intermediate product obtained in step 2 into the reaction vessel. After all the product has been added, keep the temperature for 1.5 to 2 hours. Step 4: Distill the reaction product obtained in step 3 under reduced pressure to recover the organic solvent and obtain the silane coupling agent modified chain extender.
7. The method for preparing a silane coupling agent modified chain extender according to claim 6, characterized in that, The stirring rate was 150-200 r / min, the reaction temperature was 25-35 ℃, and the dropping rate was 60-80 drops / min.
8. A one-component polyurethane potting compound, characterized in that, The single-component polyurethane potting compound is composed of poly(1,4-butanediol adipate), diphenylmethane diisocyanate, polyphenylmethylene polyisocyanate, alumina, silane coupling agent, chain extender, aldehyde imine latent curing agent, and organotin catalyst.
9. The one-component polyurethane potting compound according to claim 8, characterized in that, The mass fractions of poly(1,4-butanediol) adipate are 30-40 parts, the mass fractions of diphenylmethane diisocyanate are 10-15 parts, the mass fractions of polyphenylmethylene polyisocyanate are 8-13 parts, the mass fractions of alumina are 3-10 parts, the mass fractions of silane coupling agent modified chain extender are 1-5 parts, the mass fractions of aldehyde imine latent curing agent are 5-10 parts, and the mass fractions of organotin catalyst are 0-0.1 parts.
10. A method for preparing a one-component polyurethane potting compound, characterized in that: The specific steps include: Step 1: Weigh poly(1,4-butanediol adipate) and alumina into a reactor, disperse them by high-speed stirring, and heat to 120°C to remove water under vacuum for 2-3 hours; Step 2: Cool down to 70~80℃, turn on nitrogen gas, add diphenylmethane diisocyanate, polyphenylmethylene polyisocyanate and organotin catalyst, and keep the reaction at this temperature for 2~3 hours. Step 3: Add aldehyde-imide latent curing agent and silane coupling agent modified chain extender to the system, and continue to keep warm and stir for 0.5~1 h to obtain a one-component polyurethane potting compound.