WO2014154116A1

WO2014154116A1 - Cubic octamethyl acryloyloxy silsesquioxane crystal and preparation method thereof

Info

Publication number: WO2014154116A1
Application number: PCT/CN2014/073921
Authority: WO
Inventors: 许凯; 彭军; 陈鸣才; 于志伟
Original assignee: 中科院广州化学有限公司; 佛山市功能高分子材料与精细化学品专业中心
Priority date: 2013-03-25
Filing date: 2014-03-24
Publication date: 2014-10-02
Also published as: CN103214509A; CN103214509B

Abstract

The present invention relates to the technical field of organic-inorganic nano hybrid materials. Disclosed is a preparation method of cubic octamethyl acryloyloxy silsesquioxane crystals, the method comprising the following steps: (1) preparing the hydrolysate of γ-methacryloyloxy propyltrimethoxy silane by mixing the γ-methacryloyloxy propyltrimethoxy silane, a polar solution, and a catalyst A, conducting magnetic stirring, removing the solvent, washing until neutral, dehydrating, and filtering; (2) preparing a recondensation product of the γ-methacryloyloxy propyltrimethoxy silane by dissolving the product of step (1), adding by drops catalyst B, conducting a nitrogen gas protection reaction, washing until neutral, drying, filtering, and removing methylbenzene; (3) preparing the cubic octamethyl acryloyloxy silsesquioxane crystals by adding a crystal nucleus to the product obtained in step (2), separating out and isolating the crystals, thus yielding the cubic octamethyl acryloyloxy silsesquioxane crystals.

Description

Cubic octamethoxyacryloxysilsesquioxane crystal and preparation method thereof

The invention belongs to the technical field of organic-inorganic nano-hybrid materials, and particularly relates to a cubic sesquiterpene crystal and a preparation method thereof.

Background technique

The sesquioxane is generally a mixture obtained by hydrolytic condensation of τ-type chlorosilane or siloxane, and contains different structures of siloxane oligomers such as linear type, ladder type, cage type, and mesh type; The type sesquioxane (POSS), also known as polyhedral oligomeric sesquioxalate, is a general term for a class of sesquioxanes having a lantern-like structure. The cubic type sesquioxane is a kind of cage type sesquioxane, which has a regular structure and a high degree of symmetry, and is a τ ₈ structure. In a broad sense, in addition to the complete cage structure sesquioxalate, a partially open-structured sesquioxane is also included. From the moment PES was discovered, the synthesis of this highly symmetrical structural compound attracted the interest of researchers. In the initial stage of POSS synthesis, a simple POSS monomer is generally synthesized using T-type chlorosilane and siloxane; now, the functional group is introduced mainly on the basis of the POSS precursor, and the functional group is used to form a target product. . The synthesis methods of POSS mainly include direct hydrolysis method, functional group derivatization method and vertex cap method. Several methods for the synthesis and preparation of POSS are described in the method of forming a polyhedral oligomeric sesquioxaxosilicate (Application No.: 00813875.3) by the JC et al. patent of the American hybrid polymer company.

Application of relatively speaking, because the synthetic T ₈ POSS more mature type, therefore are focused to T ₈ POSS up type. An important feature of POSS applied to nanocomposites is its chemical modification properties, which can be covalently bonded to the matrix material through reactive groups, or can be physically blended and applied to hybrid nanocomposites to improve material properties. Octamethacryloyloxysilsesquioxane (MA-POSS) can be obtained by hydrolysis condensation of Y-methacryloxypropyltrimethoxysilane (MA) under the action of a catalyst. However, it is not uncommon to report on the hydrolysis of MA under alkaline conditions. It has been reported in the literature that MA is hydrolyzed and condensed in aqueous ethanol solution with tetramethylammonium hydroxide as a catalyst to prepare an oligomer mixture with an average molecular weight of about 5900 Da. Although there are many articles on the hydrolysis of MA, it is true that the synthesis of cubic MA-POSS in the strict sense by hydrolysis hydrolysis is not available. Although Hybrid Plastics sells these two POSS, the analysis shows that the products are sold. Still an oligomer mixture, how to prepare pure MA-POSS remains a major problem in the research field. Method for preparing methacryloyloxysilsesquioxane in a cage-type sesquioxasilicate resin having a functional group and a method for producing the same (Application No. 03154435.5), which is a patent of Japanese Nippon Steel Chemical Co., Ltd. The product obtained is structurally uncertain. It is difficult to sufficiently control the molecular weight distribution structure, and it is difficult to obtain a good yield, even if the synthesis of a sesquisilane resin having a methacryl group is carried out by the production method disclosed in Japanese Laid-Open Patent Publication No. Hei 11-29640. A silsesquioxane resin having a clear molecular structure such as a cubic structure is produced. And most of the literature on the preparation of MA-POSS does not really separate the cubic octamethacryloxy sesquioxane crystal, and it has been found that the crystallization process mostly takes too long to crystallize, the reaction conditions and the separation method. Urgent need for improvement. Therefore, it is necessary to carry out a study on the preparation of cage sesquioxalate by hydrolysis condensation method, and to study the preparation method of cubic octamethacryloxy sesquioxide crystal, which is cubic octamethacryl acyl. The application of oxysesquioxasilicate crystals provides a prerequisite. At present, it has not been reported that a cubic octamethacryloxy sesquioxane crystal has been obtained by a method of hydrolysis condensation. Summary of the invention

In order to overcome the shortcomings and deficiencies of the prior art and methods, the primary object of the present invention is to obtain a high yield (up to 90%) by the hydrolysis condensation of Y-methacryloxypropyltrimethoxysilane (MA). Crystalline cubic octamethacryloxy sesquioxane (MA-POSS of T ₈ structure).

Another object of the present invention is to provide a method for preparing and separating MA-POSS crystals of the above T ₈ structure. A further object of the present invention is to improve the groping and optimization of the above preparation and separation conditions.

The object of the invention is achieved by the following technical solution:

A cubic octamethacryloxy sesquioxane crystal is a highly symmetrical hexahedron τ ₈ having a structural formula of:

The preparation method of the above cubic octamethacryloxy sesquioxane crystal comprises the following steps:

(1) Preparation of a hydrolysis product of Y-methacryloxypropyltrimethoxysilane: mixing 25 _{g of} Y-methacryloxypropyltrimethoxysilane and 100 mL of a polar solution, and adding 10 mL of a catalyst A, magnetic stirring, solvent distillation under reduced pressure, dissolved in toluene, washed to neutral, dehydrated, filtered to obtain a hydrolysis product of Y-methacryloxypropyltrimethoxysilane;

(2) Preparation of re-condensation product of Y-methacryloxypropyltrimethoxysilyl hydrolyzate: 20 g of hydrolyzed product of Y-methacryloxypropyltrimethoxysilane of (1) Dissolved in 100 mL of low boiling non-polar solvent, adding 5 mL of Catalyst B dropwise, under nitrogen protection, magnetic stirring at 100~110 °C until the solution is a homogeneous transparent solution, heating to 115~125 °C, refluxing for 8 h, The product is taken out, washed to neutrality, dried, filtered, and toluene is removed to obtain a colorless transparent viscous liquid, which is a recondensation product of Y-methacryloxypropyltrimethoxysilyl hydrolyzate hydrolyzate;

(3) Preparation of cubic octamethacryloxy sesquioxane crystal: addition to the recondensation product of Y-methacryloxypropyltrimethoxysilyl hydrolyzate obtained in the step (2) The crystal nucleus, the crystallization temperature is controlled at 50 ° C, crystals are precipitated in the viscous liquid, and the crystal is separated to obtain a cubic octamethacryloxy sesquioxide crystal.

The polar solution described in the step (1) is ethanol, isopropanol or tetrahydrofuran; the magnetic stirring temperature is 50 to 60 ° C for 10 hours; and the catalyst A is an acidic catalyst or a basic catalyst. ; The acidic catalyst A is acid or hydrochloric acid; and the basic catalyst A is tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide or tetramethylammonium hydroxide. More preferably, the acidic catalyst A is hydrochloric acid having a concentration of 10%; more preferably, the basic catalyst A is a 10% aqueous solution of sodium hydroxide or 10% of tetramethylammonium hydroxide.

The temperature of the vacuum distillation is 60 ° C; the washing to neutral is washed with a saturated saline solution to neutral; the water removal is dried with anhydrous magnesium sulfate to remove water.

Catalytic system, temperature, solvent, system pH is the key factor affecting the first hydrazine hydrolysis reaction. The catalytic system for the hydrolysis of siloxanes has an acidic catalytic system and an alkaline catalyst system. The hydrolysis process and effect are different for the catalyst system. The solvent for the hydrolysis reaction is generally selected from polar solvents such as ethanol, isopropanol, tetrahydrofuran and the like. The reaction temperature is also a key factor in controlling the reaction. When the temperature is too low, the reaction rate will be slow, and the hydrolyzable group will be present in an unreacted state, the temperature is too high, the reaction is too high, and a complex condensation reaction is carried out. After the solvent is removed from the hydrolyzate, it is washed with a saturated saline solution to neutrality, and dried and dehydrated, which is also the key to controlling the hydrolysis product from continuing to crosslink.

The low boiling non-polar solvent described in the step (2) is benzene, toluene or xylene; the catalyst B is an acidic catalyst B or a basic catalyst B; wherein the acidic catalyst B is at a concentration of Hydrochloric acid; the basic catalyst B is an aqueous solution of sodium hydroxide or an aqueous solution of tetramethylammonium hydroxide. More preferably, the acidic catalyst B is hydrochloric acid having a concentration of 10%; more preferably, the basic catalyst B is tetramethylammonium hydroxide having a concentration of 10 to 15%.

The washing to neutrality is washed with a saturated saline solution to neutrality; the drying is carried out by using anhydrous magnesium sulfate; and the toluene removal is carried out by steaming at 60 ° C under reduced pressure to remove toluene.

The crystal nucleus described in the step (3) is octaphenylsilsesquioxane (raw material from Shanghai Aladdin Reagent Co., Ltd., purity 98.5%), and the amount is 0.01-0.05%; The solution was centrifuged and centrifuged; wherein, the centrifugal speed was 4000 rpm and the time was 30 min. Compared with the prior art, the invention has the following advantages:

(1) The present invention prepares a two-hydrolytic condensation of cubic octamethoxyacryloxysilsesquioxane crystals In the reaction, the reaction conditions are milder than those reported in the previous literature. The selection of the reaction catalyst system is also determined after comparing the catalytic effects of many different catalytic systems. The reaction is more controllable and the cage yield is higher.

(2) The invention realizes the crystallization of the T ₈ structure MA-POSS by using the method of adding a seed crystal nucleus and controlling the crystallization temperature when the cubic octamethacryloxy sesquioxane crystallization is obtained. It is the first time that a cubic octamethacryloxy sesquioxide crystal having a well-defined structure is obtained.

(3) The present invention also circumvents the ambiguity in the general synthetic POSS experiment and the uncertainty of the structure. There are many literatures on synthetically prepared MA-POSS, but most of the literature has obtained a mixed system of various structures. The present invention successfully separates cubic octamethoxyacryloxysilsesquioxane crystals.

(4) The preparation method of the cubic octamethoxyacryloxysilsesquioxane crystal of the invention has a simple process, and the selected raw materials and reagents are also relatively easy to obtain, and the reaction yield is high. DRAWINGS

Figure 1 is an iH-NMR chart of MA-POSS prepared in Example 4. It has been demonstrated that methacryloxy sesquioxalate has been successfully prepared.

2, a (b) is a mass spectrum of a colorless transparent viscous liquid of a Y-methacryloxypropyltrimethoxysilane hydrazine hydrolyzate prepared in Example 4, and 2 (b) is Example 4. a mass spectrum of the upper viscous liquid after precipitation;

3, 3(a) is a DSC chart of the obtained cubic octamethacryloxy sesquioxalate obtained by the separation of the effect of Example 4, and 3(b) is the effect of separating the crystal in Example 4. DSC chart of the post-viscous liquid.

Figure 4, 4(a) is a chemical structure diagram of cubic octamethacryloxy sesquioxalate, and 4(b) is a crystal diagram of the obtained cubic octamethacryloxy sesquioxide crystal. 4(c) is a scanning electron microscope image of cubic octamethacryloxy sesquioxide. detailed description

The present invention will be further described in detail below with reference to the embodiments, but the embodiments of the present invention are not Limited to this. Example 1

(1) Preparation of hydrolysis product of Y-methacryloxypropyltrimethoxysilane: 25 g of Y-methacryloxypropyltrimethoxysilane (MA) was added to a three-necked flask (Shanghai Aladdin Reagent) Co., Ltd.) was mixed with 100 mL of tetrahydrofuran, 10 mL of 10% HCl was added as a catalyst, and the three-necked flask was magnetically stirred at 60 ° C for 10 h. The hydrolysis reaction mixture solution was taken out, and the solvent was evaporated under reduced pressure at 60 ° C to dissolve the hydrolyzed product with 150 mL of toluene. The toluene solution was washed with a saturated aqueous solution of saline until neutral, and 15 g of anhydrous magnesium sulfate was added to remove water, and magnesium sulfate was filtered off to obtain a hydrolyzed product of Y-methacryloxypropyltrimethoxysilane.

(2) Preparation of Y-methacryloxypropyltrimethoxysilane hydrolysate recondensation product: Weigh 20g of the hydrolyzate prepared in step (1), dissolve it in 100 mL of xylene solution, and transfer the mixed solution into In a 500 mL three-necked flask, 5 mL of 10% HCl was added dropwise as a catalyst, and the three-necked flask was charged with an additional device such as a nitrogen gas shield, a thermometer, a water separator, and a condenser. The mixture was stirred under magnetic stirring at 110 ° C until the solution was a homogeneous transparent solution. The reaction temperature was raised to 120 ° C, and the reflux reaction was continued for 8 hours. The condensation product was taken out, washed with a saturated aqueous solution of sodium chloride until neutral, and dried over 15 g of anhydrous magnesium sulfate. After filtered over anhydrous magnesium sulfate, the solvent was evaporated to remove toluene solvent at 60 ° C to obtain 18.0 g of a colorless transparent viscous liquid. It is a product of re-condensation of Y-methacryloxypropyltrimethoxysilane hydrolysate in a yield of 90%.

(3) Preparation of cubic octamethacryloxy sesquioxane crystal: In 18 _{g of} Y-methacryloxypropyltrimethoxysilyl hydrolyzate hydrolysate, 0.00018 g (0.01) %) of octaphenyl POSS (raw material from Shanghai Aladdin Reagent Co., Ltd., purity 98.5%) (please provide manufacturers, such as Baiyunshan Pharmaceutical Co., Ltd.) as crystal nucleus, control crystallization temperature 50 °C, get T ₈ structure MA-POSS crystallizes. The crystal precipitation was concentrated at the bottom and was white transparent granules, and the crystallized T ₈ structure MA-POSS was separated by suction filtration, centrifugation (speed: 4000 rpm, centrifugation time: 30 min).

The obtained T ₈ structure MA-POSS crystal was characterized by MALDI-TOF MS, DSC, ^! H-NMR analysis. The characterization results indicated that the experiment successfully prepared and separated the cubic octamethacryloxy sesquioxide曰曰 Example 2

(1) Preparation of hydrolyzate of Y-methacryloxypropyltrimethoxysilane: A mixture of 25 _{g of} MA and 100 mL of ethanol was added to a three-necked flask, 10 g of deionized water and lg of sodium hydroxide were added, and a three-necked flask was placed. Magnetic stirring at 60 ° C for 10 h. The hydrolysis reaction mixture solution was taken out, and the alcohol solvent was distilled off under reduced pressure at 60 ° C, and the hydrolyzed product was dissolved in 150 mL of toluene. The toluene solution was washed with a saturated aqueous solution of saline until neutral, and water was added to remove 15 g of anhydrous magnesium sulfate, and magnesium sulfate was filtered off to obtain a hydrolyzed product containing no catalyst impurities.

(2) Preparation of Y-methacryloxypropyltrimethoxysilane hydrolysate recondensation product: Weigh 20g of hydrolyzed initial product, dissolve it in 100mL benzene solution, transfer the mixed solution into 500mL three-necked flask, drop 5 ml of 15% tetramethylammonium hydroxide was added as a catalyst, and the three-necked flask was charged with an additional device such as a nitrogen gas shield, a thermometer, a water separator, and a condenser. The mixture was refluxed with magnetic force at 110 ° C until the solution was a uniform transparent solution, and the reaction temperature was raised to 120 ° C, and the reflux reaction was continued for 8 hours. The condensation product was taken out, washed with a saturated aqueous solution of saline until neutral, and dried over 15 g of anhydrous magnesium sulfate. After filtered over anhydrous magnesium sulfate, the solvent was evaporated to remove toluene solvent at 60 ° C to obtain 18.1 g of a colorless transparent viscous liquid. The rate is 90.5%.

(3) Preparation of cubic octamethacryloxy sesquioxane crystal: In the recondensation product of 18.1 g of Y-methacryloxypropyltrimethoxysilyl hydrolyzate, 0.000181 g (0.01) %) of octaphenyl POSS (raw material from Shanghai Aladdin Reagent Co., Ltd., purity 98.5%) as crystal nucleus, control crystallization temperature 50 ° C, obtained T ₈ structure MA-POSS crystal. The crystal precipitation was concentrated at the bottom and was white transparent granules, and the crystallized T ₈ structure MA-POSS was separated by suction filtration, centrifugation (rotation speed 4000 rpm, centrifugation time 30 min).

The obtained T ₈ structure MA-POSS crystal was characterized by MALDI-TOF MS, DSC, 3⁄4-NMR analysis. The characterization results indicated that the experiment successfully prepared and separated the cubic octamethacryloxy sesquioxide bismuth oxide crucible.曰

Example 3

(1) Preparation of a hydrolysis product of Y-methacryloxypropyltrimethoxysilane: a three-necked flask A mixed solution of 25 _{g of} MA and 100 ml of ethanol was added, 10 g of deionized water and lg of sodium hydroxide were added, and the three-necked flask was magnetically stirred at 55 ° C for 10 h. The hydrolysis reaction mixture solution was taken out, and the solvent was evaporated under reduced pressure at 60 ° C, and the hydrolyzed product was dissolved in 150 ml of toluene. The toluene solution was washed with a saturated aqueous solution of saline until neutral, and water was added to remove 15 g of anhydrous magnesium sulfate, and magnesium sulfate was filtered off to obtain a hydrolyzed product containing no catalyst impurities.

(2) Preparation of re-condensation product of Y-methacryloxypropyltrimethoxysilyl hydrolyzate: Weigh 20g of the initial product of hydrolysis, dissolve it in 100mL of toluene solution, and transfer the mixed solution into a 500mL three-necked flask. Add 5 ml of 15% tetramethylammonium hydroxide as a catalyst, and the three-necked flask is equipped with an additional device such as a nitrogen gas shield, a thermometer, a water separator, and a condenser. The mixture was refluxed with magnetic force at 110 ° C until the solution was a uniform transparent solution, and the reaction temperature was raised to 120 ° C, and the reflux reaction was continued for 8 hours. The condensation product was taken out, washed with a saturated aqueous solution of sodium chloride until neutral, and dried over 15 g of anhydrous magnesium sulfate. After filtered over anhydrous magnesium sulfate, the toluene solvent was evaporated at 60 ° C to obtain 18.4 g of a colorless transparent viscous liquid. The rate is 92%.

(3) Preparation of cubic octamethacryloxy sesquioxaxyl crystallization: In the recondensation product of 18.4 g of Y-methacryloxypropyltrimethoxysilyl hydrolyzate, 0.00046 g (0.025) was added. %) of octaphenyl POSS (raw material from Shanghai Aladdin Reagent Co., Ltd., purity 98.5%) as crystal nucleus, control crystallization temperature 50 ° C, obtained T ₈ structure MA-POSS crystal. The crystal precipitation is concentrated at the bottom and is white transparent granules. After the cubic octamethacryloxy sesquioxalate is crystallized from the viscous system, it is filtered by suction and centrifuged (speed: 4000 rpm, centrifugation time: 30 min). The method was isolated to obtain a crystalline T ₈ structure MA-POSS.

Example 4

(1) Preparation of hydrolysis product of Y-methacryloxypropyltrimethoxysilane: A mixing solution of 25 _{g of} MA and 100 ml of isopropanol was added to a three-necked flask, and 10 g of deionized water and lg tetramethyl hydroxide were added. The ammonium, three-necked flask was magnetically stirred at 50 ° C for 10 h. Take out the hydrolysis reaction mixture solution, steam at 50 ° C under reduced pressure The solvent was removed, and the hydrolyzed product was dissolved in 150 ml of toluene. The toluene solution was washed with a saturated aqueous solution of saline until neutral, and 15 g of anhydrous magnesium sulfate was added to remove water, and magnesium sulfate was filtered off to obtain hydrolysis without catalyst impurities.

(2) Preparation of Y-methacryloxypropyltrimethoxysilane hydrolysate recondensation product: Weigh 20g of hydrolyzate, dissolve it in 100mL of toluene solution, transfer the mixed solution into a 500mL three-necked flask, add dropwise 5 ml of 15% tetramethylammonium hydroxide was used as a catalyst, and the three-necked flask was charged with an additional device such as a nitrogen gas shield, a thermometer, a water separator, and a condenser. The mixture was refluxed with magnetic force at 110 ° C until the solution was a uniform transparent solution, and the reaction temperature was raised to 120 ° C, and the reflux reaction was continued for 8 hours. The condensation product was taken out, washed with a saturated aqueous salt solution until neutral, and dried over 15 g of anhydrous magnesium sulfate. After filtered over anhydrous magnesium sulfate, the toluene solvent was evaporated at 60 ° C to obtain 18.5 g of a colorless transparent viscous liquid. The rate is 92.5%.

(3) Preparation of cubic octamethacryloxy sesquioxane crystal: In the recondensation product of 18.4 _{g of} Y-methacryloxypropyltrimethoxysilyl hydrolyzate, 0.00046 g (0.025) was added. %) octaphenyl POSS (raw material from Shanghai Aladdin Reagent Co., Ltd., purity 98.5%) as a crystal nucleus, the method of controlling the crystallization temperature of 50 ° C obtained MA-POSS crystal. The crystal precipitation is concentrated at the bottom and is white transparent granules. After the cubic octamethacryloxy sesquioxalate is crystallized from the viscous system, it is filtered by suction and centrifuged (speed: 4000 rpm, centrifugation time: 30 min). Method The crystallized T ₈ structure MA-POSS o was isolated. The formation of cubic octamethacryloxy sesquioxide crystals was confirmed by MS analysis. 2, a (a) is a mass spectrum of a colorless transparent viscous liquid obtained by hydrolysis and condensation of two hydrazines in an effect example, and 1455, (1746, 1814), (2105, 2173) are respectively T ₈ and Ti. , molecular peak of Ti ₂ MA-POSS; 20)) is the mass spectrum of the upper viscous liquid after precipitation in the effect example, (1746, 1814, 1831), (2105, 2173) are T ₁₍₎ , T _{12 respectively} The molecular peak of MA-POSS, the disappearance of the 1455 molecular peak indicates that the T ₈ type MA-POSS precipitated in the form of crystals.

The separation of the crystals can be analyzed by DSC. Referring to Figure 3, 3(a) is a DSC chart of the obtained cubic octamethyl acryloyloxysilsesquioxane obtained in the effect example, and it can be seen that the T ₈ type MA-POSS crystal melting peak is sharp, The melting enthalpy is large, indicating that the purity is high; 3(b) is the DSC pattern of the viscous liquid after separation in the effect example, which has no crystal melting absorption peak. The obtained T ₈ structure MA-POSS crystal was characterized by MALDI-TOF MS, DSC, 3⁄4-NMR analysis. The characterization results indicated that the cubic octamethacryloxy sesquioxalate crystal was successfully prepared and isolated. See the attached drawings.

Example 5

(1) Preparation of hydrolysis product of Y-methacryloxypropyltrimethoxysilane: A mixing solution of 25 _{g of} MA and 100 ml of isopropanol was added to a three-necked flask, and 10 g of deionized water and lg tetramethyl hydroxide were added. The ammonium, three-necked flask was magnetically stirred at 50 ° C for 10 h. The hydrolysis reaction mixture solution was taken out, and the solvent was evaporated under reduced pressure at 50 ° C, and the hydrolyzed product was dissolved in 150 ml of toluene. The toluene solution was washed with a saturated aqueous solution of saline until neutral, and 15 g of anhydrous magnesium sulfate was added to remove water, and magnesium sulfate was filtered off to obtain hydrolysis without catalyst impurities.

(2) Preparation of Y-methacryloxypropyltrimethoxysilane hydrolysate recondensation product: Weigh 20g of hydrolyzate, dissolve it in 100ml of toluene solution, transfer the mixed solution into a 500ml three-necked flask, add dropwise 5 ml of 12.5% aqueous solution of tetramethylammonium hydroxide was used as a catalyst, and the three-necked flask was charged with an additional device such as a nitrogen gas shield, a thermometer, a water separator, and a condenser. The mixture was stirred under magnetic stirring at 105 ° C until the solution was a homogeneous transparent solution. The reaction temperature was raised to 125 ° C, and the reflux reaction was continued for 8 hours. The condensation product was taken out, washed with a saturated aqueous salt solution until neutral, and dried over 15 g of anhydrous magnesium sulfate. After filtered over anhydrous magnesium sulfate, the toluene solvent was removed by rotary evaporation at 60 ° C to obtain 18.3 g of a colorless transparent viscous liquid. The rate is 91.5%.

(3) Preparation of cubic octamethacryloxy sesquioxane crystal: In the recondensation product of 18.3 _{g of} Y-methacryloxypropyltrimethoxysilyl hydrolyzate, 0.00093 g (0.05) %) octaphenyl POSS (raw material from Shanghai Aladdin Reagent Co., Ltd., purity 98.5%) As a crystal nucleus, the T ₈ structure MA-POSS crystal was obtained by controlling the crystallization temperature of 50 °C. The crystal precipitation is concentrated at the bottom and is white transparent granules. After the cubic octamethacryloxy sesquioxalate is crystallized from the viscous system, it is filtered by suction and centrifuged (speed: 4000 rpm, centrifugation time: 30 min). The method was isolated to obtain a crystalline T ₈ structure MA-POSS.

The obtained T ₈ structure MA-POSS crystal was characterized by MALDI-TOF MS, DSC, 3⁄4-NMR analysis. The characterization results indicated that the experiment successfully prepared and separated the cubic octamethoxyacryloxy sesqui Silicon silicate crucible example 6

(2) Preparation of Y-methacryloxypropyltrimethoxysilane hydrolysate recondensation product: Weigh 20g of the initial hydrolysis product, dissolve it in 100ml of toluene solution, transfer the mixed solution into a 500ml three-necked flask, and add dropwise 5 ml of 10% aqueous solution of tetramethylammonium hydroxide was used as a catalyst, and the three-necked flask was loaded with an additional device such as a nitrogen gas shield, a thermometer, a water separator, and a condenser. The mixture was stirred under magnetic stirring at 100 °C until the solution was a homogeneous transparent solution. The reaction temperature was raised to 115 ° C, and the reflux reaction was continued for 8 hours. The condensation product was taken out, washed with a saturated aqueous salt solution until neutral, and dried over 15 g of anhydrous magnesium sulfate. After filtered over anhydrous magnesium sulfate, the toluene solvent was evaporated at 60 ° C to obtain 18.2 g of a colorless transparent viscous liquid. The rate is 91%.

(3) Preparation of cubic octamethacryloxy sesquioxane crystal: In the recondensation product of 18.2 g of Y-methacryloxypropyltrimethoxysilyl hydrolyzate, 0.00091 g (0.05) %) octaphenyl POSS (raw material from Shanghai Aladdin Reagent Co., Ltd., purity 98.5%) As a crystal nucleus, the T ₈ structure MA-POSS crystal was obtained by controlling the crystallization temperature of 50 °C. The crystal precipitation is concentrated at the bottom and is white transparent granules. After the cubic octamethacryloxy sesquioxalate is crystallized from the viscous system, it is filtered by suction and centrifuged (speed: 4000 rpm, centrifugation time: 30 min). The method was isolated to obtain a crystalline T ₈ structure MA-POSS.

The obtained T ₈ structure MA-POSS crystal was characterized by MALDI-TOF MS, DSC, ^! H-NMR analysis. The characterization results indicated that the experiment successfully prepared and separated the cubic octamethacryloxy sesquioxide曰曰 The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and modifications may be made without departing from the spirit and scope of the invention. Simplifications, which are equivalent replacement means, are included in the scope of the present invention.

Claims

claims

1. A cubic octamethacryloyloxysilsesquioxane crystal, characterized by: It is a regular and highly symmetrical hexahedral τ ₈ structure, and its structural formula is:

).

2. The preparation method of cubic octamethacryloyloxysilsesquioxane crystal according to claim 1, characterized in that: comprising the following steps:

(1) Preparation of the hydrolyzate of Y-methacryloyloxypropyltrimethoxysilane: Mix 25g Y-methacryloyloxypropyltrimethoxysilane and 100mL of polar solution, add 10mL of catalyst A, Stir magnetically, remove the solvent by rotary evaporation under reduced pressure, dissolve it in toluene, wash it to neutrality, remove water, and filter it to obtain the hydrolyzate of Y-methacryloyloxypropyltrimethoxysilane;

(2) Preparation of the re-condensation product of Y-methacryloxypropyltrimethoxysilane hydrolyzate: Take 20g of the hydrolyzate of Y-methacryloxypropyltrimethoxysilane in step (1) , dissolved in 100 mL of low-boiling non-polar solvent, 5 mL of Catalyst B was added dropwise, under nitrogen protection, refluxed with magnetic stirring at 100~110°C until the solution became a uniform transparent solution, heated to 115~125°C, and refluxed for 8 hours. Take out the product, wash until neutral, dry, filter, and remove toluene to obtain a colorless and transparent viscous liquid, which is the re-condensation product of Y-methacryloxypropyltrimethoxysilane hydrolyzate;

(3) Preparation of cubic octamethacryloyloxysilsesquioxane crystal: Add to the Y-methacryloyloxypropyltrimethoxysilane hydrolyzate and recondensation product obtained in step (2) Crystal nucleus, control the crystallization temperature to 50°C, precipitate crystals from the viscous liquid, and separate the crystals to obtain cubic octamethacryloyloxysilsesquioxane crystals. 3. The preparation method according to claim 2, characterized in that: the polar solution in step (1) is ethanol, isopropyl alcohol, and tetrahydrofuran; the temperature of the magnetic stirring is 50~60°C, The time is 10h; the catalyst A is an acidic catalyst or an alkaline catalyst; the temperature of the vacuum rotary evaporation is 60 °C; the washing to neutrality is to wash to neutrality with saturated brine; the To remove water, use anhydrous magnesium sulfate to dry and remove water.

4. The preparation method according to claim 2, characterized in that: the low boiling point non-polar solvent described in step (2) is benzene, toluene or xylene; the catalyst B is an acidic catalyst B or Alkaline catalyst B; the washing to neutrality is with saturated brine; the drying is with anhydrous magnesium sulfate; the toluene removal is removed by rotary evaporation under reduced pressure at 60°C Toluene.

5. The preparation method according to claim 2, characterized in that: the crystal nucleus described in step (3) is octaphenylsilsesquioxane, and the dosage is 0.01-0.05%; The method is suction filtration and centrifugation.

6. The preparation method according to claim 3, characterized in that: the acidic catalyst A is formic acid or hydrochloric acid; the alkaline catalyst A is tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide or Tetramethylamine hydroxide.

7. The preparation method according to claim 4, characterized in that: the acidic catalyst B is hydrochloric acid with a concentration of hydrochloric acid; the alkaline catalyst B is a sodium hydroxide aqueous solution or a tetramethylammonium hydroxide aqueous solution.

8. The centrifugal speed according to claim 5 is 4000 rpm, and the centrifugation time is 30 minutes.

9. The acidic catalyst A according to claim 6 is hydrochloric acid with a concentration of 10%; the alkaline catalyst A is a sodium hydroxide aqueous solution with a concentration of 10% or 10% tetramethylamine hydroxide.

10. The acidic catalyst B according to claim 7 is hydrochloric acid with a concentration of 10%; the alkali