Silicon-based polyurethane nucleating agent and preparation method thereof

Abstract

The invention relates to the field of plastic additives, in particular to a silicon-based polyurethane nucleating agent and a preparation method thereof. In the application, a polycondensation method one-pot form is adopted, a mixture is pre-polymerized by using tetraethoxysilane, and low-molecular polyamide and C4-12 single-chain fat double-terminal amine are used as template agents, so that the prepared mesoporous silica has a good pore structure and is low in cost, and the foaming effect of polyurethane can be realized by doping only 1% of the mesoporous silica; and a polyurethane system with good strength is formed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of plastic additives, in particular to a polyurethane nucleating agent and a preparation scheme thereof. BACKGROUND

[0002] The polyurethane nucleating agent is a kind of functional additive that provides a "starting point" for bubbles in the initial stage of foaming, which can significantly change the cell number, size and distribution of the foam, thereby determining the mechanical, thermal insulation, acoustic and other properties of the final product. At present, the research on polyurethane nucleating agent is generally ordinary inorganic oxide or polypropylene nucleating agent, and the overall technical and economic indicators cannot meet the market demand. It is imperative to develop polyurethane foam nucleating agent.

[0003] The available polyurethane nucleating agent generally has several types of organic silicon surfactant, inorganic nanoparticles, soluble metal salt, oligomeric reactant, etc. Among them, the inorganic nanoparticles mainly promote the nucleation of bubbles on the surface of the nanoparticles through its high specific surface area to form the foaming effect.

[0004] At present, various domestic enterprises and high-efficiency are trying to improve the selection of nanoparticles. For example, in the thesis "Morphology and Performance Research of Silica Nanoparticle / Hard Polyurethane Foam Composite Materials" by Qingjinqi Master of China Institute of Engineering Physics, hollow mesoporous SiO ２ can be obtained by sol-gel method, which can reduce the average pore size of the foam. When the content of mesoporous SiO ２ is 1%, the enhanced polyurethane foam compression is increased by 19%, while the solid spherical SiO2 is only increased by 9%. However, the hollow mesoporous spherical SiO2 is prepared by using tetraethyl silicate as raw material and special process, which has high cost and is difficult to industrialize. For another example, Beijing Institute of Aeronautical Materials studied the nucleation effect of titanium dioxide, aluminum oxide, silicon dioxide, zirconium dioxide and other nanoparticles on polyurethane. The addition amount of the above nucleating agent generally needs to reach 5-8%, which on the one hand increases the viscosity of the system in the processing process, and on the other hand also increases the production cost of the enterprise. SUMMARY

[0005] In order to provide a polyurethane nucleating agent with simple preparation method, which can achieve good foaming effect under low dosage condition and provide higher compression performance, the present application provides a preparation method of silicon-based polyurethane nucleating agent.

[0006] Firstly, the present application provides a preparation method of silicon-based polyurethane nucleating agent, which at least includes the following steps: S1, mixing and reacting tetraethyl orthosilicate pre-polymer mixture, template agent and silane coupling agent to obtain a particle primary product; S2, removing the template agent by calcining the particle primary product to obtain a silicon-based polyurethane nucleating agent; The template agent comprises at least the following components in percentage by mass: Low-molecular polyamide 5-20%; 4-20 carbon single-chain aliphatic diamine remainder; The mass ratio of the tetraethyl orthosilicate pre-polymer mixture, the template agent and the silane coupling agent is 100:30-40:5-10.

[0007] In the above scheme, the mesoporous silica is prepared by polycondensation method, wherein the molecular chain with amino group is used as the template, and the tetraethyl orthosilicate pre-polymer mixture is used as the initial silicon compound. Overall, the reaction process is as follows: First, the connection of the tetraethyl orthosilicate pre-polymer mixture and the template agent is carried out simultaneously. In step S1, as the tetraethyl orthosilicate pre-polymer mixture is further polymerized, the template agent is mixed in the formed silica particles, and then the pore structure is generated in the calcination step of step S2. In this process, the low-molecular polyamide forms a certain micelle structure, and the long-chain aliphatic diamine is directly connected to the particles. Therefore, overall, mesoporous structures with different sizes are formed. At the same time, due to the fact that the particles with the double-end aliphatic amine are better adsorbed by the micelles, in the above process, as the reaction process proceeds, the particles obtained will form worm-like pores near the core, and larger size radial pores in the outer region. It should be noted that the low-molecular polyamide is generally a polyamide with an average molecular weight of 500-9000. In the above process, the addition of the silane coupling agent, on the one hand, couples part of the reaction sites, improves the uniformity of the dispersion of the template agent, and on the other hand, the silane coupling agent can also provide a certain grafting coupling on the surface of the formed mesoporous silica, improving the dispersibility of the obtained nucleating agent.

[0008] After the preparation of the above nucleating agent system, a high specific surface area is first provided, which will bring good gas storage performance, thereby realizing the effect of rapid desorption of gas and large pore density. At the same time, under the action of the silane coupling agent, the overall system has low tackifying effect and has no effect on the processing of polyurethane, and also will not agglomerate in the system, causing foam collapse or mechanical property decline. At the same time, due to the fact that it forms radial pores with large size through low-molecular polyamide, the above pores help the rapid entry and exit of gas, and the polyol used to prepare polyurethane will not enter the pores, but can use the pore as an anchor point to promote the early phase separation or crystallization of the local hard segment microzone, form a rigid "shell", inhibit bubble merging and Ostwald ripening, and finally prepare polyurethane with uniform bubble distribution and good compression strength.

[0009] It should be noted that the tetraethyl orthosilicate pre-polymer mixture generally refers to a system containing tetraethyl orthosilicate, tetraethyl orthosilicate oligomers and silicon dioxide, such as TEOS, TEOS-28, TEOS-40 and the like. In the above scheme, the tetraethyl orthosilicate pre-polymer mixture is preferably TEOS-40, and TEOS-40 is selected in the system, and after curing, the system contains 40% by mass of silicon dioxide, and in the reaction process, the silicon dioxide can be used as the basis for the formation of mesoporous silica, thereby providing a more stable and narrow particle size system, thereby inducing the polyurethane to form a more stable foam size, and the pore size distribution is more concentrated. At the same time, the low molecular weight polyamide is preferably 200 low molecular weight polyamide, and the pore structure formed by 200 low molecular weight polyamide and the amount of gas generated are moderate, which helps the gas in the polyurethane system to be more uniformly distributed, so that the formed foamed polyurethane has better strength, which may be related to the molecular weight and amine value of the polyamide. The molecular weight determines the chain length, and thus determines the continuity of the pore, and to some extent also plays a role in controlling the wall thickness, while the amine value determines the reaction rate between the silane coupling agent, which is too fast or too slow will cause the mesoporous molding problem. The silane coupling agent is preferably methyl triethoxysilane. The methyl triethoxysilane as the silane coupling agent participates in the reaction, first of all, it will not affect the formation process of polyurethane, and a small amount of silane coupling agent adsorbed in the pore will not participate in the reaction of polyurethane, so that the polyurethane is more prone to produce larger grains near the nucleating agent, thereby improving the overall strength.

[0010] On the basis of the above, further preferably, in step S1, tetramethoxysilane is also added, and the mass ratio of the tetramethoxysilane to the tetraethyl orthosilicate pre-polymer mixture is 1-3:100.

[0011] In the above scheme, tetramethoxysilane is added as an auxiliary nucleating system, and tetramethoxysilane has a faster reaction rate and is easily adsorbed on the surface of TEOS-40 silicon dioxide in the system. A large amount of Si(OH)4 monomers is released instantaneously by hydrolysis, and is quickly pinned on the surface of the micelle, and the condensation exotherm makes the local supersaturation degree suddenly increase, providing additional nucleation sites and improving the density of the pores. At the same time, by using a high template content and additional oligomeric amide system, a stable pore size is formed, and the water resistance and heat resistance are also improved. Therefore, it is helpful to obtain a more uniform bubble system for the nucleating agent, and also improves the reinforcing effect of the nucleating agent on the polyurethane system.

[0012] In the above scheme, in the step S1, the tetraethyl orthosilicate pre-polymer mixture, the template agent, the tetramethoxysilane and the first part of the silane coupling agent are first reacted, and when the reaction time is 50-75% of the total reaction time, the remaining part of the silane coupling agent is added, and the first part of the silane coupling agent accounts for 30-60% of the total amount of the silane coupling agent.

[0013] In the above scheme, the silane coupling agent is added to the system in two times, and since the tetramethoxysilane has been added to the system, the addition of the silane coupling agent in two times helps to improve the dispersibility of the obtained mesoporous silica, reduces the agglomeration of the nucleating agent in the process of preparation and sintering, and further improves the uniformity of the particle size distribution. At the same time, the silane coupling agent added later can also play a role in sealing the pores, thereby limiting the entry of the polyol molecules into the pores, forming the effect that the pores can pass gas but cannot pass liquid, improving the subsequent foaming capacity and the pressure resistance of the obtained polyurethane.

[0014] Preferably, in the step S1, the reaction time is 4-6 h, the reaction temperature is 50-70℃, the solvent is water or a mixed solvent of water and an aprotic organic solvent, and the mass concentration of the tetraethyl orthosilicate pre-polymer mixture is 30-50 mg / mL. Under the above reaction conditions, the particle size of the system can be well controlled to form a more uniform pore structure and particle morphology.

[0015] Preferably, in the step S2, the specific steps are as follows: S2-1: The prepared particles are rapidly cooled to not higher than 10℃, followed by centrifugation and washing with ethanol and water; S2-2: After drying, calcination is performed at 550-700℃ for 4-6 h.

[0016] In the above scheme, rapid cooling can as much as possible avoid the sedimentation of the mesoporous silica, terminate the polycondensation reaction of the system, reduce the effect of aggregation caused by the increase of the surface energy of the particles due to the tetramethoxysilane, and at the same time provide good uniformity.

[0017] Preferably, the 4-12 carbon single-chain aliphatic double-end amine is octane diamine or decane diamine.

[0018] In the above scheme, the even carbon number diamine with a long carbon chain is used, and the amino groups of the even number of carbon chains generally point to the same side, which is more easily combined with the silicon particles to form a stable pore structure, providing better gas production performance and better strength in product angle.

[0019] In addition, the application also relates to the polyurethane nucleating agent prepared by the preparation method; the average particle size of the silicon-based polyurethane nucleating agent is 100-150 nm, the nucleating agent with the particle size of 100-150 nm can be obtained by controlling the reaction conditions, the particle size is relatively close to the lattice size of the polyurethane foam, and therefore the polyurethane system formed in the foaming process is more uniform and stable, and the strength of the polyurethane is better realized.

[0020] In conclusion, the application provides a polyurethane nucleating agent, which is prepared by a one-step reaction method, mesoporous silica nanoparticles are formed by using a composition of tetraethyl orthosilicate and a template agent, low-molecular polyamides and fatty diamines are used as the template, and the mesoporous channels are closed by using a silane coupling agent, so that good gas production and reinforcing effects can be realized, and the compressive strength of the obtained foamed polyurethane is greatly improved under the condition that the content is only 1%. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a scanning electron microscope graph of Example 1.

[0022] Figure 2 is Figure 1 is a particle size distribution graph after particle size analysis in Example 1.

[0023] Figure 3 is an XRD spectrum graph of Example 1. DETAILED DESCRIPTION

[0024] In the following examples, the polyurethane nucleating agent is involved, and the macroscopic and microscopic appearances of the mesoporous silica nanoparticles prepared by the nucleating agent are evaluated in the following two dimensions. 1. The macroscopic and microscopic appearances of the mesoporous silica nanoparticles prepared by the nucleating agent are evaluated, including whether the appearance is agglomerated, particle size and specific surface area, wherein the particle size is calculated by sampling in the SEM electron microscope graph, the average particle size is mainly investigated, and the uniformity of the particle size is also observed. The specific surface area is determined by the BET method. In addition, the most probable pore size of part of the examples is determined by the BJH desorption method.

[0025] 2. The product is mixed into the polyurethane system at a mass fraction of 1%, foamed polyurethane is prepared, and then the density, tear strength, tensile strength and 10% compression strength of the foamed polyurethane are characterized. The foamed polyurethane is prepared by the following scheme. BASF's polyurethane black material M20S and polyurethane white material Elastopor CH1141C-A were selected, and 1% by mass of the following nucleating agent was added at a black material / white material mass ratio of 1.2:1. Subsequently, the mixture was injected into a foaming mold at a pressure of 130 bar, a material temperature of 18-20°C, a flow rate of 400 g / s, a mold temperature of 40°C, and a curing time of 5 min. After the foam was removed from the mold, it was placed at room temperature for 24 h, and then cut into sample sizes for standby use.

[0026] The technical solutions of the present application are further described in the following specific embodiments.

[0027] In Example 1, a preparation method of a silicon-based polyurethane nucleating agent is provided, which specifically includes the following steps: S1, TEOS-40 (CFS-062 from KF Science), a template agent, a silane coupling agent, and tetramethoxysilane were mixed and reacted in water to obtain a granular primary product. In each 100 mL of water as a solvent system, the added material components were as follows: TEOS-40: 5 g; The template agent included 0.2 g of low-molecular-weight polyamide and 1.8 g of octacarbodi-amine. The low-molecular-weight polyamide was Type 200 low-molecular-weight polyamide, specifically TY-200 from Haiyan, with an amine value of 245 mgKOH / g. The silane coupling agent was specifically methyltriethoxysilane, with a mass of 0.5 g. Tetramethoxysilane, 0.1 g.

[0028] Specifically, the reaction process of step S1 was as follows: The silane coupling agent was divided into two portions of 0.25 g. One portion of the silane coupling agent was used as the first portion of the silane coupling agent, which was mixed with TEOS-40, the template agent, and tetramethoxysilane, and then added to water. The temperature was controlled at 60°C, and the mixture was stirred at a speed of 500 rpm for 2.5 h. Then, the remaining silane coupling agent was added, and the mixture was continuously reacted for 2.5 h to obtain the granular primary product.

[0029] S2, calcination was performed on the granular primary product to remove the template agent, specifically including the following steps: S2-1, an ice-water mixture was added to rapidly reduce the system temperature to not higher than 10°C, and then rapid centrifugation was performed. After removing the supernatant, the system was washed twice with water and ethanol, respectively. S2-2, after drying the above system, calcination was performed at 600°C for 5 h to obtain the polyurethane nucleating agent.

[0030] In Example 1, the particle morphology of the prepared polyurethane nucleating agent under a scanning electron microscope was as shown in Figure 1 The particle size distribution was as shown inFigure 2 XRD pattern is shown as Figure 3 In Example 1, the average particle size of the product prepared is 128.5 nm, the specific surface area is 898 m 2 / g, the most probable pore size is 5.58 nm measured by BJH desorption.

[0031] In Example 2, on the basis of Example 1, the most suitable particle size of the above-mentioned polyurethane nucleating agent in the system is studied by adjusting the preparation process. Specifically, on the basis of Example 2, the mass ratio of TEOS-40, template agent, silane coupling agent and tetramethoxysilane is fixed, and other process parameters are adjusted, and the experimental results are shown in Table 1.

[0032]

[0033] Overall, the particle size and specific surface area of the particles are approximately inversely proportional, but in the case of further reducing the particle size, due to the high surface energy, the reaction rate is faster, so the load of the template agent in the system will be slower than the larger particle size, which will further lead to a smaller increase in the specific surface area.

[0034] Example 1 and Example 2 are verified in polyurethane, and the results are shown in Table 2.

[0035]

[0036] As can be seen from Table 2, the selection of particle size will obviously affect the performance of polyurethane. Overall, based on similar particle morphology, as the particle size increases, the specific surface area and gas production performance of the system will be weakened to a certain extent, which will further lead to a certain weakening of the mechanical properties of the system. Mesoporous silica particles with too small particle size will lead to a decrease in effective nucleation, and the viscosity of the reaction process is easy to rise. In the case of small particles, mesoporous silica is more likely to agglomerate, which will lead to the formation of large pores between particles and particles, which will lead to a significant decrease in the strength of polyurethane.

[0037] In Example 3, on the basis of Example 1, the effect of different tetraethyl orthosilicate pre-polymer mixtures in the system is further studied, and whether to add silane coupling agent and tetramethoxysilane is compared to verify the effect of the selection of tetraethyl orthosilicate pre-polymer mixture on the system. In the example, two kinds of tetraethyl orthosilicate systems, TEOS-28 and TEOS-40, are selected, and the specific experimental results are shown in Table 3.

[0038]

[0039] From the data in Table 3, it can be seen that when no silane coupling agent is added, the system is more prone to agglomeration, while tetramethoxysilane in the system helps to reduce the most probable pore size to some extent, while reducing the average particle size.

[0040] In addition, from the experimental data above, it can be seen that under the same reaction conditions, TEOS-28 will form a pore structure smaller in size than TEOS-40, which is reflected in the increase in specific surface area and the decrease in the most probable pore size. In order to improve the performance, after further adjusting the amount of TEOS-28 and other parameters, Example 3-6 is obtained to obtain a particle size similar to that of Example 1. Specifically, the adjusted experimental conditions and the final product parameters are as follows: The mass of TEOS-28 is 7.5g per 100mL of solvent, the template and the selected low molecular weight polyamide are 0.5g and octacarbonyl diamine is 2.5g, the mass of silane coupling agent is 0.75g, the mass of tetramethoxysilane remains unchanged, the reaction temperature is 45°C, and the rest of the conditions remain unchanged. The average particle size of the mesoporous silica obtained is 110.6nm, the specific surface area is 1035.9m 2 / g, and the most probable pore size is 5.20nm.

[0041] Example 3 is verified as a whole, and the results are shown in Table 4.

[0042]

[0043] From the experimental results in Table 4, it can be seen that in the overall comparison, although the addition of silane coupling agent has little effect on the specific surface area and particle size of the whole, on the one hand, its non-addition will cause the particles to have obvious agglomeration, which will ultimately affect the molding of the product, and at the same time, it is easy to disperse unevenly in the polyurethane system, causing the overall strength of the polyurethane system to be significantly lost. The tetramethoxysilane in the system plays a role in enriching the particle pore, greatly improving the tear strength and tensile strength of the polyurethane as a whole.

[0044] Example 4, based on Example 1, further verifies the addition time, amount and type of silane coupling agent. Specifically, the experimental groups are shown in Table 5.

[0045]

[0046] It should be noted that the addition time of the silane coupling agent has a small effect on the particle size of the final reaction, and the early addition of the silane coupling agent will appropriately increase the specific surface area, but the overall effect is small, so it can be considered that the effect of different experimental groups on the strength of the polyurethane in this example is not due to the particle morphology.

[0047] In addition, the above experimental results can show that the time of adding the silane coupling agent can significantly affect the dispersibility of the particles. In the presence of tetramethylsilane, if the amount of the silane coupling agent is added too early or too late, the system will have certain agglomeration. The reason can be that the early addition of the silane coupling agent will cause the silane coupling agent to be combined inside the mesoporous silica, thereby failing to play a dispersing effect. If the addition is too late, certain agglomeration will occur during the reaction process, resulting in a decrease in the specific surface area and a poor morphology.

[0048] Further specific experiments were conducted on the experimental groups in Table 5, and the results are shown in Table 6.

[0049]

[0050] In the above scheme, it can be seen that the silane coupling agent needs to be added twice, and the time point of the second addition of the silane coupling agent needs to be in the middle and late stages of the reaction process. The reason is that it is important to disperse the mesoporous silica by the silane coupling agent when the mesoporous silica is initially formed after the reaction has proceeded to a certain extent. At the same time, among the various silane coupling agents, only methyl triethoxysilane with a carbon-silicon bond has better performance. On the one hand, it helps to reduce the entry of polyols into the pores, thereby improving the mechanical properties of the polyurethane and the gas production performance of the system as a whole. On the other hand, it also reduces the influence of the nucleating agent on the viscosity of the system. In addition, the agglomeration of the nucleating agent will significantly affect the gas production performance and mechanical strength.

[0051] It should be noted that in Examples 4-10, excessive silane coupling agent was added. Although the particle size is still within the system range, and the specific surface area reaches 808 m 2 / g, the excessive silane coupling agent on the surface makes it difficult for the nucleating agent system to combine with the polyurethane system, thereby affecting the mechanical properties of the final polyurethane. In Examples 4-11 to 4-14, compared with Example 1, the silane coupling agent was replaced, and silane coupling agents with acyloxy and amino groups were used. Overall, they have lower mechanical properties than Example 1. The reason can be that methyl triethoxysilane has less influence on the reaction process of polyurethane curing, and also provides better hydrophobicity, thereby causing a certain improvement in strength.

[0052] Example 5, based on Example 1, the amount of tetramethoxysilane added was adjusted. The amount of tetramethoxysilane added and the corresponding experimental results are shown in Table 7.

[0053]

[0054] From the above experimental results, it can be seen that the addition of tetramethoxysilane not only causes the particle size of the system to decrease and the specific surface area to increase, but also controls the pore of mesoporous silica to achieve better gas production effect and better strength. In addition, due to the provision of a partially twisted lattice structure, better strength is provided. However, when the amount of tetramethylsilane added is too much, the system will agglomerate due to the too fast reaction rate, thereby causing the loss of strength.

[0055] In this embodiment, different types and proportions of low molecular polyamides are adjusted orthogonally based on the embodiment 1, and the specific experimental groups are shown in Table 8.

[0056]

[0057] In the above table, the 650 low molecular polyamide specifically uses Haiyan TY-650, and the amine value is 215 mgKOH / g. The 651 low molecular polyamide specifically uses Haiyan TY-651, and the amine value is 393 mgKOH / g.

[0058] Experiments are conducted on the nucleating agents in Table 8, and the results are shown in Table 9.

[0059]

[0060] From the above experimental data, it can be seen that under the condition of fixed overall amount of template, a small amount of added oligomeric amide can significantly improve the strength of the system. The reason is that the polyamide template forms a part of the large pore structure, which can quickly react with the polyol and isocyanate in the large pore structure, thereby better playing the role of anchor point, so that the polyurethane molecular chain can better form entanglement around the nucleating agent, thereby improving the strength effect. At the same time, the large pores formed by the polyurethane also help to quickly and uniformly produce gas, thereby stabilizing the density and improving the bubble uniformity. The overall density has little effect, but it has a significant impact on the compressive strength of the system. However, too much addition of polyurethane will also cause the wall thickness of mesoporous silica to thicken and the specific surface area to decrease. In addition, it is found through experiments that the 200 type low molecular polyamide provides better strength performance in the above system. In addition to its moderate amine value which can improve the reaction mildness and reduce defects, it may also be related to its better molecular chain flexibility.

[0061] This specific embodiment is only an explanation of the present application, and is not a limitation of the present application. Those skilled in the art can make modifications to the present embodiment without creative contribution after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A method for preparing a silicon-based polyurethane nucleating agent, characterized by, At least comprising the following steps: S1, mixing reaction of tetraethyl orthosilicate pre-polymer mixture, template agent and silane coupling agent to obtain particle primary product; S2, removing template agent by calcination of particle primary product to obtain silicon-based polyurethane nucleating agent; The template agent comprises at least the following components in mass percentage: Low molecular weight polyamide 5-20%; 4-12 carbon single-chain fatty diamine in balance; The mass ratio of the tetraethyl orthosilicate pre-polymer mixture, template agent and silane coupling agent is 100:30-40:5-10.

2. The method for preparing a silicon-based polyurethane nucleating agent according to claim 1, characterized in that, In step S1, the silane coupling agent is methyl triethoxysilane.

3. The method for preparing a silicone-based polyurethane nucleating agent according to claim 1, characterized in that, The tetraethyl orthosilicate pre-polymer mixture is TEOS-40.

4. The method of claim 3, wherein the silicon-based polyurethane nucleating agent is prepared by the reaction of a polyol, a diisocyanate, and a chain extender. In step S1, tetramethoxysilane is also added, and the mass ratio of the tetramethoxysilane and the tetraethyl orthosilicate pre-polymer mixture is 1-3:

100.

5. The method for preparing a silicone-based polyurethane nucleating agent according to claim 1, characterized in that, The low molecular weight polyamide is 200 low molecular weight polyamide.

6. The method for preparing a silicone-based polyurethane nucleating agent according to claim 4, characterized in that, In step S1, the tetraethyl orthosilicate pre-polymer mixture, template agent, tetramethoxysilane and the first part of the silane coupling agent are reacted, and when the reaction time is 50-75% of the total reaction time, the remaining part of the silane coupling agent is added, and the first part of the silane coupling agent accounts for 30-60% of the total amount of the silane coupling agent.

7. The method for preparing a silicone-based polyurethane nucleating agent according to claim 6, characterized in that, In step S1, the reaction time is 4-6h, the reaction temperature is 50-70℃, the solvent is water or a mixed solvent of water and an aprotic organic solvent, and the mass concentration of the tetraethyl orthosilicate pre-polymer mixture is 30-50 mg / mL.

8. The method for preparing a silicone-based polyurethane nucleating agent according to claim 1, characterized in that, In step S2, the specific steps are as follows: S2-1: rapidly cooling the prepared particles to not higher than 10℃, then centrifuging and cleaning with ethanol and water; S2-2: after drying, calcining at 550-700℃ for 4-6h.

9. The method for preparing a silicone-based polyurethane nucleating agent according to claim 1, characterized in that, The 4-12 carbon single-chain fatty diamine is octane diamine or decane diamine.

10. The silicon-based polyurethane nucleating agent according to any one of claims 1 to 9, characterized in that, The average particle size of the silicon-based polyurethane nucleating agent is 100-150nm.

Images