Preparation method of hyperbranched methoxy silicone oil
By synthesizing hyperbranched cores and constructing flexible shell structures in a microchannel reactor, the problem of insufficient low-temperature crystallization and high-temperature thermal stability of traditional methoxy silicone oils has been solved, enabling efficient, low-emission continuous production that is suitable for new energy batteries and aerospace applications.
Patent Information
- Application Number
- CN202511703572.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-01-20
AI Technical Summary
Traditional methoxy silicone oils are prone to crystallization at low temperatures and have insufficient thermal stability at high temperatures. The production process involves long reaction cycles, low by-product recovery rates, high VOC emissions, unstable branching, and a wide molecular weight distribution, which limits their application in a wide temperature range.
Hyperbranched cores were synthesized in a microchannel reactor using a metal-organic framework catalyst and combined with a flexible linear shell structure. Hyperbranched methoxy silicone oil was then purified by membrane distillation and molecular distillation, enabling precise control of branching degree and continuous production.
It achieves performance stability of hyperbranched methoxy silicone oil over an ultra-wide temperature range, reduces viscosity change rate and thermal weight loss rate, improves methanol recovery rate, and reduces VOC emissions, making it suitable for high-end fields such as new energy batteries and aerospace.
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of organic silicon material synthesis, in particular to a preparation method of hyperbranched methoxy silicone oil. BACKGROUND
[0002] As a high-performance organic silicon material, methoxy silicone oil is widely used in the fields of aerospace, new energy batteries, electronic packaging and the like due to its excellent high and low temperature resistance, hydrophobicity and chemical stability. However, the traditional linear structure methoxy silicone oil has obvious defects: crystallization at low temperature (such as below-60 DEG C) leads to a sharp rise in viscosity, and the thermal stability is insufficient at high temperature (such as above 250 DEG C), with a weight loss rate often higher than 5%, which limits its application in a wide temperature range.
[0003] In addition, the production of the existing methoxy silicone oil mostly adopts a batch process, and problems such as a long reaction period (more than 10 hours), a low recovery rate of byproduct methanol (usually less than 70%), a high emission of volatile organic compounds (VOCs) (a concentration greater than 100 mg / m 3 ) and the like exist, and the environmental protection and economic benefits are poor. Although certain research is conducted on the market, linear products are still mainly used, and problems such as unstable branching degree control (a fluctuation range of ±10%), a wide molecular weight distribution (PDI>2.0) and the like exist, and high-end products are dependent on imports.
[0004] Therefore, it is of important industrial value and strategic significance to develop a methoxy silicone oil synthesis technology which is controllable in branching degree, narrow in molecular weight distribution, has excellent high and low temperature performance and is suitable for continuous clean production. SUMMARY
[0005] The technical problem to be solved by the application is to overcome the above technical difficulties, and a preparation method of hyperbranched methoxy silicone oil is provided, which can accurately control the branching degree of the product, realize continuous, short-process and low-emission production, and the obtained product has wide temperature range stability, low viscosity change rate and excellent thermal conductivity performance.
[0006] To solve the above technical problems, the technical scheme provided by the application is as follows:
[0007] A preparation method of hyperbranched methoxy silicone oil, comprising the following steps:
[0008] Step one, under the action of a metal organic framework (MOFs) catalyst, trifunctional methoxy silane is allowed to react in a microchannel reactor to form a hyperbranched core;
[0009] Step two, bifunctional methoxy silane is gradually added to the hyperbranched core to form a flexible linear shell, and a "hyperbranched core-flexible linear shell" structure is constructed;
[0010] Step three, purification by membrane distillation combined with molecular distillation to obtain the hyperbranched methoxy silicone oil.
[0011] The MOFs catalyst is a metal organic framework material with a pore size of 0.5-2.0 nm, preferably ZIF-8, MIL-101 or UiO-66.
[0012] The branching degree of the hyperbranched core is 20%-40% with a control accuracy of ±5%.
[0013] The reaction temperature of the micro-channel reactor is 40-120℃, and the material residence time is 5-15 minutes.
[0014] The membrane distillation is hydrophobic membrane distillation, and the methanol recovery rate is not less than 98%.
[0015] The molecular weight of the hyperbranched methoxy silicone oil is 5000-15000 g / mol, and the molecular weight distribution index (PDI) is ≤1.8.
[0016] The viscosity of the hyperbranched methoxy silicone oil at-100℃ is not more than 5000 mPa·s, and the thermal weight loss rate at 300℃ is not more than 3%.
[0017] The continuous flow reaction system for implementing the preparation method comprises a micro-channel reactor, an online infrared spectrum monitoring device, a ceramic membrane filter, a hydrophobic membrane distillation device and a short-range molecular distillation device.
[0018] The hyperbranched methoxy silicone oil has a "hyperbranched core-flexible linear shell" structure, a glass transition temperature (Tg) ≤-100℃, and a thermal decomposition temperature (Td) ≥350℃.
[0019] The advantages of the present application compared with the prior art are:
[0020] 1. The present application constructs a "hyperbranched core-flexible linear shell" specific structure through a "step-by-step synthesis" strategy, effectively inhibits low-temperature crystallization and high-temperature degradation, and realizes the performance stability of the product in a super-wide temperature range (-100℃ to 300℃).
[0021] 2. The present application combines MOFs catalysts with micro-channel continuous flow reaction technology, realizes accurate control of branching degree (20%-40%, accuracy ±5%) and efficient and continuous reaction process, and shortens the reaction time from more than 10 hours of traditional process to within 15 minutes.
[0022] 3. The present application integrates membrane distillation-molecular distillation purification process, and the methanol recovery rate is as high as more than 98%, which significantly reduces VOCs emission (≤30 mg / m 3 ), and the catalyst can be recycled, meeting the requirements of green chemical industry.
[0023] 4、The obtained silicone oil has a narrow molecular weight distribution, excellent thermal stability and rheological properties, and is suitable for high-end fields such as new energy battery heat-conducting packaging and aerospace lubrication, and the thermal resistance can be reduced by about 30%, and the friction coefficient fluctuation after high-low temperature cycle is ≤5%. DETAILED DESCRIPTION
[0024] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, the term "includes" and any variation thereof is intended to cover non-exclusive inclusion.
[0025] The present application will be further described in detail below in conjunction with the embodiments.
[0026] Example 1
[0027] A preparation method of a hyperbranched methoxy silicone oil, comprising the following steps:
[0028] Step one, in the presence of a metal organic framework catalyst, trifunctional methoxy silane is reacted in a microchannel reactor to form a hyperbranched core; the branching degree of the hyperbranched core is 40%, and the control accuracy is +5%; the molecular weight of the hyperbranched methoxy silicone oil is 15000 g / mol, and the molecular weight distribution index (PDI) is ≤1.8; the reaction temperature of the microchannel reactor is 120℃, and the material residence time is 15 minutes; the viscosity of the hyperbranched methoxy silicone oil at -100℃ is not more than 5000 mPa·s, and the thermal weight loss rate at 300℃ is not more than 3%; the MOFs catalyst is a metal organic framework material with a pore size of 2.0 nm, preferably ZIF-8;
[0029] Step two, gradually adding bifunctional methoxy silane to the hyperbranched core to form a flexible linear shell and build a "hyperbranched core-flexible linear shell" structure;
[0030] Step three, the hyperbranched methoxy silicone oil is obtained by combined purification of membrane distillation and molecular distillation. The membrane distillation is hydrophobic membrane distillation, and the methanol recovery rate is not less than 98%. The hyperbranched methoxy silicone oil has a "hyperbranched core-flexible linear shell" structure, a glass transition temperature (Tg) ≤ ~ 100℃, and a thermal decomposition temperature (Td) ≥ 350℃.
[0031] A continuous flow reaction system for implementing the preparation method, comprising: a microchannel reactor; an online infrared spectrum monitoring device; a ceramic membrane filter; a hydrophobic membrane distillation device; and a short-path molecular distillation device.
[0032] Example 2
[0033] A preparation method of a hyperbranched methoxy silicone oil, comprising the following steps:
[0034] Step one, in the presence of metal organic framework catalyst, trifunctional methoxysilane is reacted in a microchannel reactor to form a hyperbranched core; the branching degree of the hyperbranched core is 20%, and the control precision is -5%; the molecular weight of the hyperbranched methoxysilicone oil is 5000 g / mol, and the molecular weight distribution index (PDI) is ≤1.8; the reaction temperature of the microchannel reactor is 40℃, and the material residence time is 5 minutes; the viscosity of the hyperbranched methoxysilicone oil at -100℃ is not more than 5000 mPa·s, and the thermal weight loss rate at 300℃ is not more than 3%; the MOFs catalyst is a metal organic framework material with a pore size of 0.5 nm, preferably UiO-66;
[0035] Step two, gradually adding bifunctional methoxysilane to the hyperbranched core to form a flexible linear shell and construct a "hyperbranched core-flexible linear shell" structure;
[0036] Step three, the hyperbranched methoxysilicone oil is obtained by combined purification of membrane distillation and molecular distillation. The membrane distillation is hydrophobic membrane distillation, and the methanol recovery rate is not less than 98%. The hyperbranched methoxysilicone oil has a "hyperbranched core-flexible linear shell" structure, a glass transition temperature (Tg) ≤ ~ 100℃, and a thermal decomposition temperature (Td) ≥ 350℃.
[0037] A continuous flow reaction system for implementing the preparation method, comprising: a microchannel reactor; an online infrared spectrum monitoring device; a ceramic membrane filter; a hydrophobic membrane distillation device; and a short path molecular distillation device.
[0038] The above describes the present application and its embodiments, which are not limited. If a person skilled in the art is inspired by it, without departing from the purpose of the present application, similar embodiments can be designed without creative design, which should belong to the protection scope of the present application.
Claims
1. A process for the preparation of hyperbranched methoxysilicone oil, characterized in that, The method comprises the following steps: Step 1: reacting trifunctional methoxysilane in the presence of a metal organic framework (MOFs) catalyst in a microchannel reactor to form a hyperbranched core; Step 2: gradually adding bifunctional methoxysilane to the hyperbranched core to form a flexible linear shell and construct a "hyperbranched core-flexible linear shell" structure; Step 3: purifying by combining membrane distillation and molecular distillation to obtain the hyperbranched methoxysilicone oil.
2. The method for preparing a hyperbranched methoxy silicone oil according to claim 1, characterized in that: The MOFs catalyst is a metal organic framework material with a pore size of 0.5-2.0 nm, preferably ZIF-8, MIL-101 or UiO-66.
3. The method for preparing a hyperbranched methoxy silicone oil according to claim 1, characterized in that: The degree of branching of the hyperbranched core is 20%-40%, with a control accuracy of ±5%.
4. The method for preparing a hyperbranched methoxy silicone oil according to claim 1, characterized in that: The reaction temperature of the microchannel reactor is 40-120℃, and the residence time of the material is 5-15 minutes.
5. The method for preparing a hyperbranched methoxy silicone oil according to claim 1, characterized in that: The membrane distillation is hydrophobic membrane distillation, and the methanol recovery rate is not less than 98%.
6. The method for preparing a hyperbranched methoxy silicone oil according to claim 1, characterized in that: The molecular weight of the hyperbranched methoxysilicone oil is 5000-15000 g / mol, and the molecular weight distribution index (PDI) is ≤1.
8.
7. The method for preparing a hyperbranched methoxy silicone oil according to claim 1, characterized in that: The viscosity of the hyperbranched methoxysilicone oil at -100℃ is not more than 5000 mPa·s, and the thermal weight loss rate at 300℃ is not more than 3%.
8. The method according to any one of claims 1 to 7, characterized in that: A continuous flow reaction system for implementing the preparation method, comprising: a microchannel reactor; an online infrared spectrum monitoring device; a ceramic membrane filter; a hydrophobic membrane distillation device; and a short path molecular distillation device.
9. The method for preparing a hyperbranched methoxy silicone oil according to claim 8, characterized in that: The hyperbranched methoxysilicone oil has a "hyperbranched core-flexible linear shell" structure, a glass transition temperature (Tg) ≤-100℃, and a thermal decomposition temperature (Td) ≥350℃.