Preparation method of long-chain alkane silicone oil

Abstract

The invention relates to the field of organic silicon materials, and particularly discloses a preparation method of long-chain alkane silicone oil, which comprises the following steps: S1, in an inert gas environment, mixing a chloroplatinic acid solution and a sodium borohydride solution, stirring until the solution is black colloid, washing to obtain a platinum colloid catalyst, dispersing the platinum colloid catalyst in propyl alcohol, and drying to obtain a platinum colloid precursor; the mass ratio of the chloroplatinic acid solution to the sodium borohydride solution is (1: 2)-(1.5: 2); s2, olefin and side hydrogen-containing silicone oil are mixed, a platinum colloid catalyst is added, a long-chain alkane silicone oil crude product is obtained, the mass ratio of olefin to side hydrogen-containing silicone oil is 1: 1-1.2: 1, and the mass ratio of olefin to the platinum colloid catalyst is 200: 1-250: 1; s3, distilling the long-chain alkane silicone oil crude product, controlling the pressure intensity at 1kPa, heating to 80-85 DEG C, and collecting undistilled substances to obtain long-chain alkane silicone oil; and S4, recovering the platinum colloid catalyst. The preparation method provided by the invention can improve the product purity.

Description

Technical Field

[0001] The present application relates to the field of organosilicon materials, and more specifically, to a method for preparing long-chain alkane silicone oil. Background Art

[0002] Long-chain alkane silicone oil is a type of organic silicon compound that is chemically modified by introducing long-chain alkyl groups into the main chain or side chain of siloxane. It has the characteristics of silicone oil such as high and low temperature resistance, low surface tension, and lubricity. At the same time, due to the hydrophobicity and compatibility of long-chain alkyl groups, it has great application prospects.

[0003] Traditional methods for preparing long-chain alkane silicone oils typically use chloroplatinic acid as a catalyst and then synthesize it through a hydrosilylation reaction. However, these methods have the following drawbacks: the reaction rate of chloroplatinic acid is slow; because it is an acidic catalyst and a homogeneous catalyst, it must be dissolved before participating in the reaction and is easily affected by factors such as solution temperature and pH; and after the reaction is completed, chloroplatinic acid is difficult to separate, resulting in the presence of chloroplatinic acid in the product, leading to reduced product purity and other problems. Summary of the Invention

[0004] In order to solve the problems existing in the prior art and improve the purity of the product, the present application provides a method for preparing a long-chain alkane silicone oil, which specifically comprises the following steps: S1: In an inert gas environment, chloroplatinic acid solution and sodium borohydride solution are mixed and stirred until the solution becomes a black colloid, and a platinum colloid catalyst is obtained after washing, and the platinum colloid catalyst is dispersed in propanol; the chloroplatinic acid solution is 0.01 mol / L, the sodium borohydride solution is 0.1 mol / L, and the mass ratio of the chloroplatinic acid solution to the sodium borohydride solution is 1:2-1.5:2; S2: Alkene is mixed with hydrogen-containing silicone oil, the platinum colloid catalyst is added, and the mixture is stirred. The steps of: step S3: distilling the crude long-chain alkane silicone oil, controlling the pressure to be 1 kPa, raising the temperature to 80-85° C., maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain the long-chain alkane silicone oil; and step S4: recovering the platinum colloid catalyst from the long-chain alkane silicone oil.

[0005] Preferably, the inert gas environment is an argon environment.

[0006] By adopting the above technical solution, platinum colloid is generated through the reduction reaction of chloroplatinic acid and sodium borohydride. The inert gas environment can prevent the platinum colloid from oxidizing and ensure the stability of the catalyst. The mass ratio of chloroplatinic acid to sodium borohydride is 1:2-1.5:2, which can not only optimize the reduction rate but also avoid colloid agglomeration caused by excessive reduction. Propanol is used as a dispersant to improve the dispersibility of the platinum colloid in the reaction system, which can further reduce agglomeration. The mass ratio of olefin to side hydrogen-containing silicone oil is 1:1-1.2:1, which not only balances the reactant concentration but also avoids the formation of byproducts caused by excessive side hydrogen-containing silicone oil. The catalytic efficiency of the platinum colloid catalyst is relatively high. Limiting the mass ratio of olefin to platinum colloid catalyst ensures catalytic efficiency while reducing production costs.

[0007] Vacuum distillation avoids product decomposition caused by high temperatures and reduces energy consumption. After the reaction is complete, the platinum colloidal catalyst can be recovered through centrifugation or magnetic separation.

[0008] The present application uses a platinum colloid catalyst to catalyze the synthesis of long-chain alkane silicone oil from olefins and pendant hydrogen-containing silicone oil. On the one hand, because the platinum colloid can provide more active sites, accelerate the reaction rate, and have a higher catalytic efficiency, the amount used is relatively small; at the same time, since the platinum colloid after the reaction is recovered, the possibility of impure products caused by excessive residues after large-scale use of the catalyst is further reduced; at the same time, the platinum colloid replaces chloroplatinic acid, avoiding the possibility of acidic residues in the product and also improving the purity of the product.

[0009] Preferably, microwave catalysis is used in the S2 reaction process; more preferably, the microwave power is 75-85W.

[0010] By employing this technical solution, microwave radiation accelerates the thermal motion of reactant molecules, shortening reaction times to 30-60 minutes. The non-thermal effect of microwaves reduces the activation energy of the reaction, while also avoiding side reactions caused by localized overheating, reducing the likelihood of impurities in the product and improving product purity.

[0011] Preferably, the S1 further comprises dissolving ferrous sulfite and ferric chloride in deionized water, stirring the mixture evenly, mixing the mixture with a chloroplatinic acid solution and a sodium borohydride solution, adjusting the pH to 9-10, adding a sodium citrate solution, stirring the mixture at 50-60° C. for 2-3 hours to form a black suspension, and separating solid particles to obtain a platinum colloidal catalyst, wherein the mass ratio of the ferrous sulfite to the ferric chloride is 1:1-1:2, and the mass ratio of the ferrous sulfite to the chloroplatinic acid is 1:4-1:5.

[0012] By adopting the above technical solution, adding Fe 2 ⁺ / Fe 3⁺ Salt, Fe3O4@Pt composite particles are generated by co-reduction method, sodium citrate assists in forming a stable core-shell structure, and the saturation magnetization intensity enables the rapid separation of the platinum colloid catalyst and the reaction system through an external magnetic field, facilitating the separation of the platinum colloid catalyst from the long-chain alkane silicone oil and improving the purity of the long-chain alkane silicone oil.

[0013] Preferably, the step of separating the solid particles to obtain the platinum colloid catalyst comprises: using a permanent magnet to adsorb the solid particles to obtain the platinum colloid catalyst.

[0014] By adopting the above technical solution, permanent magnets are used to absorb solid particles, making it easy to separate the solid particles quickly and conveniently.

[0015] Preferably, S4 is specifically: using magnetic separation to recover the platinum colloidal catalyst, specifically including: S4-1: using a permanent magnet to collect the platinum colloidal catalyst; S4-2: washing the separated platinum colloidal catalyst 2-3 times in a propanol solution to obtain a washed platinum colloidal catalyst; S4-3: dispersing the washed platinum colloidal catalyst in the propanol solution.

[0016] By adopting the above technical solution, the platinum colloidal catalyst can be easily collected by a permanent magnet, and the adsorbed impurities can be removed by propanol washing and dispersed in propanol for subsequent use.

[0017] Preferably, the mass ratio of olefin to platinum colloid catalyst is 245: 1-255: 1. By further limiting the ratio of platinum colloid catalyst, the amount of catalyst used can be reduced while ensuring that the catalytic efficiency meets the requirements.

[0018] In summary, this application has at least the following beneficial effects: A platinum colloidal catalyst was prepared by the reduction reaction of chloroplatinic acid and sodium borohydride, and propanol was used as a dispersant to improve the colloidal stability, replacing the traditional chloroplatinic acid catalyst and avoiding the negative impact of residual strong acidic substances on product purity.

[0019] Ferric sulfite and ferric chloride are further added to generate Fe3O4@Pt magnetic composite particles through a co-reduction method. Sodium citrate is then added to stabilize the core-shell structure, giving the catalyst saturation magnetization. After the reaction, the catalyst can be quickly and completely recovered using permanent magnets or magnetic separation technology, preventing the introduction of impurities from catalyst residues. This design not only reduces catalyst usage but also efficiently separates the catalyst from the product through magnetic separation technology, significantly improving the purity of the long-chain alkane silicone oil.

[0020] 3. During the reaction phase, microwave radiation with a power of 75-85W is introduced to utilize its non-thermal effect to accelerate the thermal motion of reactant molecules, shortening the reaction time while reducing the activation energy and avoiding side reactions caused by local overheating. Furthermore, a strict mass ratio of olefin to pendant hydrogen-containing silicone oil is set at 1:1-1.2:1 to balance the reactant concentrations and reduce byproducts caused by excessive pendant hydrogen-containing silicone oil. Furthermore, vacuum distillation is used to avoid high-temperature decomposition products. This synergistic effect significantly reduces byproduct formation and further improves product purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the infrared spectrum of the product octyl silicone oil. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the examples. Unless otherwise specified, the raw materials required for the examples and comparative examples in the present invention are all conventional commercial brands or obtained through conventional preparation processes.

[0023] Example 1 S1: In an argon environment, 0.01 mol / L chloroplatinic acid solution and 0.1 mol / L sodium borohydride solution were mixed in a mass ratio of 1:2, and stirred until the solution became a black colloid. After washing, a platinum colloid catalyst was obtained, and the platinum colloid catalyst was dispersed in propanol; S2: mixing octene and MDHM, adding a platinum colloid catalyst, stirring and mixing, and reacting at room temperature and pressure until the octene conversion rate reaches 96% to obtain a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1:1, and the mass ratio of octene to the platinum colloid catalyst is 200:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4: Separating the octyl silicone oil and the platinum colloid catalyst by centrifugation, and dispersing the recovered platinum colloid catalyst in propanol.

[0024] Example 2 S1: In a helium environment, 0.01 mol / L chloroplatinic acid solution and 0.1 mol / L sodium borohydride solution were mixed at a mass ratio of 1.5:2, and stirred until the solution became a black colloid. After washing, a platinum colloid catalyst was obtained, and the platinum colloid catalyst was dispersed in propanol; S2: mixing octene and MDHM, adding a platinum colloid catalyst, stirring and mixing, and reacting at room temperature and pressure until the octene conversion rate reaches 97% to obtain a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1.2:1, and the mass ratio of octene to platinum colloid catalyst is 300:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 85°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4: Separating the octyl silicone oil and the platinum colloid catalyst by centrifugation, and dispersing the recovered platinum colloid catalyst in propanol.

[0025] Example 3 S1: In an argon environment, a 0.01 mol / L chloroplatinic acid solution and a 0.1M 0.1 mol / L sodium borohydride solution were mixed in a mass ratio of 1:2, and stirred until the solution became a black colloid. The platinum colloid catalyst was obtained after washing, and the platinum colloid catalyst was separated by centrifugation. The platinum colloid catalyst was dispersed in propanol; S2: octene and MDHM are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 85W microwave coordinated catalysis until the octene conversion reaches 96%, thereby obtaining a crude octyl silicone oil product. The mass ratio of octene to MDHM is 1:1, and the mass ratio of octene to platinum colloid catalyst is 245:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4: Separate the octyl silicone oil and the platinum colloid catalyst by centrifugation, and recover the platinum colloid catalyst and disperse it in propanol.

[0026] Example 4 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:1 are dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2, the mass ratio of ferric sulfite to chloroplatinic acid being 1:4, the pH being adjusted to 9, sodium citrate solution being added, and the mixture being stirred at 50°C for 2 hours to form a black suspension, the solid particles being separated using a permanent magnet to obtain a platinum colloidal catalyst, and the platinum colloidal catalyst being dispersed in propanol to obtain a platinum colloidal catalyst; S2: octene and MDHM are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 75W microwave coordinated catalysis until the octene conversion reaches 96%, thereby obtaining a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1:1, and the mass ratio of octene to platinum colloid catalyst is 255:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst in a propanol solution three times to obtain a washed platinum colloidal catalyst; S4-3: The washed platinum colloidal catalyst is dispersed in a propanol solution to complete recovery.

[0027] Example 5 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:2 are dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2, the mass ratio of ferric sulfite to chloroplatinic acid being 1:5, the pH being adjusted to 10, sodium citrate solution being added, and the mixture being stirred at 60°C for 3 hours to form a black suspension, the solid particles being separated using a permanent magnet to obtain a platinum colloidal catalyst, and the platinum colloidal catalyst being dispersed in propanol; S2: octene and MDHM are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 80W microwave coordinated catalysis until the octene conversion rate reaches 96%, thereby obtaining a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1:1, and the mass ratio of octene to platinum colloid catalyst is 200:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst twice in a propanol solution to obtain a washed platinum colloidal catalyst; S4-3: Dispersing the washed platinum colloidal catalyst in a propanol solution to complete recovery.

[0028] Example 6 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:2 are dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2, the mass ratio of ferric sulfite to chloroplatinic acid being 1:5, the pH being adjusted to 10, sodium citrate solution being added, and the mixture being stirred at 60°C for 3 hours to form a black suspension, the solid particles being separated using a permanent magnet to obtain a platinum colloidal catalyst, and the platinum colloidal catalyst being dispersed in propanol; S2: octene and MDHM are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 80W microwave coordinated catalysis until the octene conversion rate reaches 96%, thereby obtaining a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1:1, and the mass ratio of octene to platinum colloid catalyst is 200:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst twice in a propanol solution to obtain a washed platinum colloidal catalyst; S4-3: Dispersing the washed platinum colloidal catalyst in a propanol solution to obtain a platinum colloidal catalyst.

[0029] Example 7 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:2 are dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2, the mass ratio of ferric sulfite to chloroplatinic acid being 1:5, the pH being adjusted to 10, sodium citrate solution being added, and the mixture being stirred at 60°C for 3 hours to form a black suspension, the solid particles being separated using a permanent magnet to obtain a platinum colloidal catalyst, and the platinum colloidal catalyst being dispersed in propanol; S2: octene and MDHM are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 80W microwave coordinated catalysis until the octene conversion rate reaches 96%, thereby obtaining a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1.1:1, and the mass ratio of octene to platinum colloid catalyst is 200:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst twice in a propanol solution to obtain a washed platinum colloidal catalyst; S4-3: Dispersing the washed platinum colloidal catalyst in a propanol solution.

[0030] Example 8 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:2 are dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2, the mass ratio of ferric sulfite to chloroplatinic acid being 1:5, the pH being adjusted to 10, sodium citrate solution being added, and the mixture being stirred at 60°C for 3 hours to form a black suspension, the solid particles being separated using a permanent magnet to obtain a platinum colloidal catalyst, and the platinum colloidal catalyst being dispersed in propanol; S2: octene and MDHM are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 80W microwave coordinated catalysis until the octene conversion reaches 96%, thereby obtaining a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1.1:1, and the mass ratio of octene to platinum colloid catalyst is 250:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst twice in a propanol solution to obtain a washed platinum colloidal catalyst; S4-3: Dispersing the washed platinum colloidal catalyst in a propanol solution.

[0031] Example 9 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:1 were dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2 (the mass ratio of ferric sulfite to chloroplatinic acid was 1:4). The pH was adjusted to 9, and sodium citrate solution was added and stirred at 50°C for 3 hours to form a black suspension. The solid particles were separated using a permanent magnet to obtain a platinum colloidal catalyst, which was then dispersed in propanol. S2: octene and MDHM are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 80W microwave coordinated catalysis until the octene conversion rate reaches 96%, thereby obtaining a crude octyl silicone oil product, wherein the mass ratio of octene to MDHM is 1:1, and the mass ratio of octene to platinum colloid catalyst is 200:1; S3: Distilling the crude octyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80°C, maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain octyl silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst twice in a propanol solution to obtain a washed platinum colloidal catalyst; S4-3: Dispersing the washed platinum colloidal catalyst in a propanol solution.

[0032] Example 10 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:1 are dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2, the mass ratio of ferric sulfite to chloroplatinic acid being 1:4, the pH being adjusted to 9, sodium citrate solution being added, and the mixture being stirred at 50°C for 2 hours to form a black suspension, the solid particles being separated using a permanent magnet to obtain a platinum colloidal catalyst, and the platinum colloidal catalyst being dispersed in propanol to obtain a platinum colloidal catalyst; S2: 1-decene and R=decane were mixed, a platinum colloid catalyst was added, the mixture was stirred and mixed, and the mixture was reacted at room temperature and pressure under 75W microwave coordinated catalysis until the octene conversion reached 96%, thereby obtaining a crude octyl silicone oil product, wherein the mass ratio of the 1-decene to the R=decane was 1:1, and the mass ratio of the 1-decene to the platinum colloid catalyst was 255:1; S3: Distilling the crude decyl silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80° C., maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain decyl silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst in a propanol solution three times to obtain a washed platinum colloidal catalyst; S4-3: The washed platinum colloidal catalyst is dispersed in a propanol solution to complete recovery.

[0033] Example 11 S1: In an argon environment, ferric sulfite and ferric chloride in a mass ratio of 1:1 are dissolved in deionized water, stirred evenly, and mixed with a 0.01 mol / L chloroplatinic acid solution and a 0.1 mol / L sodium borohydride solution in a mass ratio of 1:2, the mass ratio of ferric sulfite to chloroplatinic acid being 1:4, the pH being adjusted to 9, sodium citrate solution being added, and the mixture being stirred at 50°C for 2 hours to form a black suspension, the solid particles being separated using a permanent magnet to obtain a platinum colloidal catalyst, and the platinum colloidal catalyst being dispersed in propanol to obtain a platinum colloidal catalyst; S2: 1-octadecene and R=octadecane are mixed, a platinum colloid catalyst is added, the mixture is stirred and mixed, and the mixture is reacted at room temperature and pressure under 75W microwave coordinated catalysis until the conversion of 1-octadecene reaches 96%, thereby obtaining a crude octadecyl-modified silicone oil product, wherein the mass ratio of 1-octadecene to R=octadecane is 1:1, and the mass ratio of 1-octadecene to the platinum colloid catalyst is 255:1; S3: distilling the crude octadecyl-modified silicone oil, controlling the pressure at 1 kPa, raising the temperature to 80° C., maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain the octadecyl-modified silicone oil; S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst in a propanol solution three times to obtain a washed platinum colloidal catalyst; S4-3: The washed platinum colloidal catalyst is dispersed in a propanol solution to complete recovery.

[0034] Comparative Example 1 Commercially available HMOTS.

[0035] Comparative Example 2 The difference from Example 4 is that the mass ratio of chloroplatinic acid solution to sodium borohydride is 1:1.

[0036] Comparative Example 3 The difference from Example 4 is that the mass ratio of octene to MDHM is 0.8:1.

[0037] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) Steps: Sample preparation: Digestion: Weigh 1 g of sample, add 5 mL of aqua regia (HNO3:HCl=1:3), and microwave digestion (180℃, 30 min).

[0038] Dilute to volume: Transfer the digestion solution to a 50 mL volumetric flask, dilute to volume with ultrapure water, and filter through a 0.22 μm filter.

[0039] Instrument parameters: RF power: 1550W.

[0040] Carrier gas flow rate: 1.0 L / min (Ar).

[0041] Detection mode: He collision mode.

[0042] Test results The platinum residual levels of Examples 1-3 are between 3-5ppb, and the residue is mainly due to the poor catalyst recovery efficiency. In Example 2, the increase in the octene / MDHM ratio leads to an increase in the viscosity of the system, uneven dispersion of the catalyst, and a slightly higher residue, but overall it is still significantly better than the comparative example. In Example 3, microwave-assisted accelerated reaction, the residue is equivalent to that of Example 1, so there is no effect on the purity of the product under the condition of microwave-accelerated reaction. Example 4-11: By forming Fe3O4@Pt, the platinum residue is significantly reduced to ≤2ppb, so when the catalyst is optimized to Fe3O4@Pt that can be magnetically separated by magnetic materials, the purity of the product is higher. Examples 7-11 further optimize the process parameters, and the platinum residue is further reduced to ≤1.5ppb, so further optimization of the parameters can improve the purity of the product. Example 3-4 further has no significant effect on the purity of the product by limiting the proportion of platinum colloidal catalyst. Examples 10-11 demonstrate that 1-decene and R=decane and 1-octadecene and R=octadecane can generate corresponding long-chain alkane silicone oils, while the platinum residue is significantly reduced to ≤2 ppb. The catalyst is Fe3O4@Pt that can be magnetically separated by magnetic materials, and the product purity is higher.

[0043] The commercially available product had a high platinum residual of 21.3 ppb. Compared with Examples 1-11, Examples 1-11 all significantly improved product purity. In Comparative Example 2, excessive chloroplatinic acid caused platinum agglomeration, reducing recovery efficiency. In Comparative Example 3, the low octene ratio led to MDHM self-aggregation and severe catalyst encapsulation, affecting product purity.

[0044] In Examples 1-3, no iron residue was found due to the lack of active iron source addition. In Examples 4-11, iron residue was also ≤ 1 ppb, indicating that magnetic nanoparticle modification and efficient recovery methods had no significant impact on iron residue. The reduction in iron residue in Examples 7-11 was attributed to the optimization of process parameters.

[0045] The commercially available product had an iron residue of 0.3 ppb, suggesting the possibility of contamination during production and transportation. In Comparative Example 2, the iron residue level was high, and excessive chloroplatinic acid caused Pt nanoparticle agglomeration, reducing recovery efficiency. In Comparative Example 3, the low octene ratio led to MDHM self-aggregation, severe catalyst encapsulation, and increased residue.

[0046] The solution of this application can significantly reduce platinum residues, and microwave assistance can accelerate the reaction rate without affecting product optimization. Optimization of process parameters can further reduce platinum residues.

[0047] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing long-chain alkane silicone oil, characterized in that: The following steps are involved: S1: In an inert gas environment, mixing chloroplatinic acid solution and sodium borohydride solution, stirring until the solution becomes a black colloid, washing to obtain a platinum colloid catalyst, and dispersing the platinum colloid catalyst in propanol; The chloroplatinic acid solution is 0.01 mol / L, the sodium borohydride solution is 0.1 mol / L, and the mass ratio of the chloroplatinic acid solution to the sodium borohydride solution is 1:2-1.5:2; S2: mixing the olefin and the pendant hydrogen-containing silicone oil, adding the platinum colloid catalyst, stirring and mixing, and reacting at room temperature and pressure to obtain a crude long-chain alkane silicone oil product; The mass ratio of the olefin to the pendant hydrogen-containing silicone oil is 1:1-1.2:1, and the mass ratio of the olefin to the platinum colloid catalyst is 200:1-300:1; S3: distilling the crude long-chain alkane silicone oil product, controlling the pressure at 1 kPa, raising the temperature to 80-85° C., maintaining the temperature until no distillate is produced, and collecting the undistilled material to obtain the long-chain alkane silicone oil; S4: Recovering the platinum colloidal catalyst from the long-chain alkane silicone oil.

2. The method for preparing long-chain alkane silicone oil according to claim 1, wherein Microwave assisted catalysis is used in the S2 reaction process.

3. The method for preparing long-chain alkane silicone oil according to claim 2, wherein The microwave power for the synergistic catalysis in S2 is 75-85W.

4. The method for preparing long-chain alkane silicone oil according to claim 1, wherein The S1 further comprises dissolving ferric sulfite and ferric chloride in deionized water, stirring the mixture uniformly, mixing the mixture with a chloroplatinic acid solution and a sodium borohydride solution, adjusting the pH to 9-10, adding a sodium citrate solution, stirring the mixture at 50-60° C. for 2-3 hours to form a black suspension, and separating solid particles to obtain a platinum colloidal catalyst, wherein the mass ratio of the ferric sulfite to the ferric chloride is 1:1-1:2, and the mass ratio of the ferric sulfite to the chloroplatinic acid is 1:4-1:

5.

5. The method for preparing long-chain alkane silicone oil according to claim 4, wherein The method of separating solid particles to obtain a platinum colloid catalyst specifically comprises: using a permanent magnet to adsorb solid particles to obtain a platinum colloid catalyst.

6. The method for preparing long-chain alkane silicone oil according to claim 4, wherein The S4 specifically comprises: recovering the platinum colloidal catalyst by magnetic separation.

7. The method for preparing long-chain alkane silicone oil according to claim 6, wherein Said S4 comprises, S4-1: Collection of platinum colloidal catalyst using a permanent magnet; S4-2: washing the separated platinum colloidal catalyst in a propanol solution 2-3 times to obtain a washed platinum colloidal catalyst; S4-3: Dispersing the washed platinum colloidal catalyst in a propanol solution.

8. The method for preparing long-chain alkane silicone oil according to claim 1, wherein The mass ratio of the olefin to the platinum colloid catalyst is 245:1-255:1.

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