NL2033665B1

NL2033665B1 - High-temperature-resistant organic silicone elastomer and preparation method thereof

Info

Publication number: NL2033665B1
Application number: NL2033665A
Authority: NL
Inventors: Yu Hua; Zhang Yuefeng; Min Lili; Liu Minqi; Zhao Chaowei; Fang Jie; Yan Qingjia; You Shengyong
Original assignee: Inst Applied Chemistry Jiangxi Academy Sciences; Jiangxi Rongxin Tech Silicon Industry Co Ltd
Priority date: 2022-08-31
Filing date: 2022-12-05
Publication date: 2024-03-12
Also published as: CN115490863B; CN115490863A

Abstract

Disclosed, are a high—temperature—resistant organic silicone elastomer and a preparation method thereof. The preparation method includes the following steps: uniformly mixing a hydroxyl silicone oil and, a silane monomer cross—linking agent, adding KH550 and stannous octoate, and allowing the mixture for static reaction curing, wherein the hydroxyl silicone oil is a Hethyl—terminated hydroxyl silicone oil, and the silane monomer cross—linking agent is methyltrimethoxysilane or phenyltrimethoxysilane. The present invention relates to preparation methods of three materials, i.e. non—nanoparticle modified organic silicone elastomer, titanium dioxide nanoparticle modified organic silicone elastomer and titanium—oxo cluster nanoparticle modified, organic silicone elastomer. In these materials, the titanium—oxo cluster nanoparticle modified silicone elastomer has superior high temperature resistance, a thermal collapse temperature up to 460°C and good thermal stability, with promising commercial application prospects.

Description

HIGH-TEMPERATURE-RESISTANT ORGANIC SILICONE ELASTOMER AND

PREPARATION METHOD THEREOF

TECHNICAL FIELD

The present invention belongs to the technical field of func- tional materials, and particularly relates to a high-temperature- resistant organic silicone elastomer and a preparation method thereof.

BACKGROUND ART

The description herein provides the background art related to the present invention only, and does not necessarily constitute the prior art.

Organic silicone elastomers are widely applied in construc- tion, automobiles, ships, chemical engineering, leather, medicine and medical treatment, electronics and other areas due to their excellent properties such as cold and thermal stability, weather resistance, electrical insulation, ozone resistance, physiological inertia, low surface tension and low surface energy. Common organ- ic silicone elastomers can maintain good mechanical, physical, electrical and surface properties for a long term when used at a temperature between -40°C and 200°C, but their properties are greatly impaired at an excessively high or low temperature. Howev- er, in special fields such as aerospace, chip manufacturing, mem- brane separation and chromatographic separation, organic silicone elastomers are required to work at 300-350°C or even a higher tem- perature over a long period of time while maintaining good thermo- dynamic stability. Common organic silicone elastomer materials ob- viously cannot meet the requirements of such special fields.

SUMMARY

To overcome the shortcomings in the prior art, the present invention is intended to provide a high-temperature-resistant or- ganic silicone elastomer and a preparation method thereof.

The present invention realizes the aforesaid purpose through the following sclutions:

In the first aspect, the present invention provides a prepa- ration method of a high-temperature-resistant organic silicone elastomer, including the following steps: uniformly mixing a hydroxyl silicone oil and a silane monomer cross-linking agent, adding KH550 and stannous octoate, and allow- ing the mixture for static reaction curing, wherein the hydroxyl silicone oil is a methyl-terminated hydroxyl silicone oil; and the silane monomer cross-linking agent is methyltrimethox- ysilane or phenyltrimethoxysilane.

In the second aspect, the present invention provides a high- temperature-resistant organic silicone elastomer prepared by the preparation method.

One or more embodiments of the present invention achieve the following beneficial effects: (1) The preparation conditions of the titanium-oxo cluster nanoparticles of the present invention are mild, the production steps are simple, and raw materials are easily available. The product solution has high processibility and the cluster nano-size is suitable, which is in favour of realizing the covalent combina- tion of clusters and the organic silicone elastomer. The synthesis is simple, the cost is controllable, and homogeneous treatment is possible. {2) The process route of the titanium-oxo cluster modified organic silicone elastomer of the present invention is simple, raw materials are cheap, easily available and environmentally friend- ly, the thermal collapse temperature of the product is effectively increased, the heat resistance is greatly enhanced and the produc- tion cost is low, beneficial to accelerating the industrializa- tion. (3) The present invention relates to preparation methods of three materials, i.e. non-nanoparticle modified organic silicone elastomer, titanium dioxide nanoparticle modified organic silicone elastomer and titanium-oxo cluster nanoparticle modified organic silicone elastomer. In these materials, the titanium-oxo cluster nanoparticle modified silicone elastomer has superior high temper-

ature resistance, a thermal collapse temperature up to 460°C and good thermal stability, with promising commercial application pro- spects.

BRIEF DESCRIPTION OF THE DRAWINGS

As a part of the present invention, the accompanying drawings described herein are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and the description thereof are used to explain the pre- sent invention, and will not constitute an improper limitation to the present invention.

FIG. 1 is a TGA spectrum of a methyltrimethoxysilane modified high-temperature-resistant organic silicone elastomer prepared in example 1 of the present invention.

FIG. 2 is a TGA spectrum of a phenyltrimethoxysilane modified high-temperature-resistant organic silicone elastomer prepared in example 2 of the present invention.

FIG. 3 is a TGA spectrum of a high-temperature-resistant or- ganic silicone elastomer prepared by adding 4% of TiO; nanoparti- cles in example 3 of the present invention.

FIG. 4 is a TGA spectrum of a high-temperature-resistant or- ganic silicone elastomer prepared by adding 2% of TiO; nanoparti- cles in example 4 of the present invention.

FIG. 5 is a TGA spectrum of a high-temperature-resistant or- ganic silicone elastomer prepared by adding 1% of titanium-oxo clusters in example 5 of the present invention.

FIG. 6 is a TGA spectrum of a high-temperature-resistant or- ganic silicone elastomer prepared by adding 1% of titanium-oxo clusters in example 6 of the present invention.

FIG. 7 is a TGA spectrum of a high-temperature-resistant or- ganic silicone elastomer prepared by adding 2% of titanium-oxo clusters in example 7 of the present invention.

FIG. 8 is a TGA spectrum of a high-temperature-resistant or- ganic silicone elastomer prepared by adding 4% of titanium-oxo clusters in example 8 of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

It should be noted that the following details are exemplary and are intended to give a further explanation to the present in- vention. Unless otherwise specified, all technological and scien- tific terms used herein have the same meanings as commonly under- stood by those of ordinary skill in the art.

In the first aspect, the present invention provides a prepa- ration method of a high-temperature-resistant organic silicone elastomer, including the following steps: a hydroxyl silicone oil and a silane monomer cross-linking agent are uniformly mixed, KH550 and stannous octoate are added, and the mixture is allowed for static reaction curing, wherein the hydroxyl silicone oil is a methyl-terminated hydroxyl silicone oil; and the silane monomer cross-linking agent is methyltrimethox- ysilane or phenyltrimethoxysilane.

In some embodiments, the method further includes a step of modifying the organic silicone elastomer by adding titanium diox- ide nanoparticles or cyclic titanium-oxo cluster molecules

Ti1320:6 (EG) 32 (PAc):18(EtO)1is to the reaction system, wherein EG is eth- ylene glycol, PAc is deprotonated propionic acid, and EtO is deprotonated ethanol.

The cyclic titanium-oxo cluster molecules

Ti3,0:6 (EG) 3, (PAC) 16 (EL0O) ys have abundant organic ligands on the pe- riphery, so that the titanium-oxo cluster nanoparticles have good solution processibility in organic solvents, wherein EG is the ab- breviation of ethylene glycol, PAc is the abbreviation of deproto- nated propionic acid, and EtO is the abbreviation of deprotonated ethanol.

Preferably, the cyclic titanium-oxo cluster molecules are added in a form of a dichloromethane solution of cyclic titanium- oxo clusters, wherein a concentration may be 80-120 mg/mL, such as 100 mg/mL.

Conventional titanium oxide nanoparticles can hardly be fully mixed with the organic silicone elastomer and are prone to severe aggregation, which is adverse to improving the overall performance of the organic silicone elastomer. The titanium-oxo clusters are soluble in dichloromethane and are conveniently added to the prep- aration formula of the organic silicone elastomer by means of a solution, so that the additive titanium-oxo clusters can be fully mixed with the organic silicone elastomer. This is the biggest 5 difference from conventional titanium oxide nanoparticles as an additive.

A preparation method of the dichloromethane solution of cy- clic titanium-oxo clusters includes the following steps: 600 mg of a titanium-oxo cluster solid is weighed and placed in a reagent bottle, 6 mL of dichloromethane is added, and ultrasonic treatment is performed until the solid fully dissolves; the resulting solu- tion is a 100 mg/mL dichloromethane solution of titanium-ozo clus- ters.

Preferably, a structural formula of the cyclic titanium-oxo cluster molecules Tis3:0:s (EG): (PAC). (Et0) 5 is as follows: i AN

B ~ As I TN = { t Fr RE

ET Vor

WRAY i RE

Ki he IN Di Yond FBR ae “N fe ny de] ee TN nd ee

LeU Fad Nm dee NR . ab AA Te ed Sp N

NAAT ee eee STE a eed

Ie XO Ad

Ee Nea ie [Pa en os be Te Bed TN … 4 ad 1 Ne

Ha Ch 3 NN 3 A AN i | \, Ng, /

ISSR DAT f Al ee

SN or LT we eT Ge LT ATT

Ney dE i en

BA dn LORY

VESTN RET ee seem TTT ATED

PTR NNT em NIT NT

Poo dT eR EIA NH w we TTT RE LT LA 1 AERTS AY A ee TS Pea { omy ATT ese Wd : ~eA wt Ly { 3 Lo ri Be ; j 3 t { h ae Rr Ze boo be SN dx we” ì ‚

Further preferably, a preparation method of the cyclic tita- nium-oxo cluster molecules Ti3:0:s(EG)3:(PAc)}:s{EtO):s includes the following steps: titanium isopropoxide is added to a mixed solution of propi- onic acid and ethylene glycol, and the mixture is uniformly mixed, sealed, heated and stirred at 90-110°C for 20-30 h to obtain the cyclic titanium-oxo cluster molecules Tis0:¢ (EG) sz (PAC) 15(ELO) ig.

The titanium-oxo clusters can not only be used as a heat-

resistant additive for conventional inorganic oxide nanoparticles, but also contain 16 freely reactive hydroxyl sites on the periph- ery, which can react with siloxanes respectively to form C-0-Si covalent bonds, playing a role of covalent cross-linking. In addi- tion, some ligands on surfaces of the clusters can exchange with ligands of incompletely reacted silicon hydroxyl groups in the or- ganic silicone elastomer to form Si-0-Ti covalent bonds, further improving the thermal stability of the organic silicone elastomer.

In some embodiments, a viscosity of the methyl-terminated hy- droxyl silicone oil is 650-750 cp.

In some embodiments, the titanium dioxide nanoparticles are

P25-type with an average particle diameter of 25 nm. The titanium dioxide nanoparticles have large specific surface areas, good thermal stability and other favorable properties.

In some embodiments, the silane monomer cross-linking agent is phenyltrimethoxysilane.

In some embodiments, a molar ratio of the hydroxyl silicone oil, the silane monomer cross-linking agent, KH550 and the stan- nous octoate is 1040:15-25:3:1.

Preferably, a mass of the titanium dioxide nanoparticles is 2-4% of that of the hydroxyl silicone oil.

Preferably, a mass of the cyclic titanium-oxo clusters is 1- 4% of that of the hydroxyl silicone oil.

In some embodiments, a temperature of the static reaction curing is room temperature, i.e. 20-30°C.

The present invention will be further described below in de- tail in conjunction with specific embodiments, and it should be noted that the specific embodiments are given as an explanation of the present invention, rather than a limitation.

The organic solvents used in all embodiments are analytically pure.

Example 1 Preparation of high-temperature-resistant organic silicone elastomer by modification of methyltrimethoxysilane

The specific preparation steps are as follows:

10 g of methyl-terminated hydroxyl silicone oil with a vis- cosity of 700 cp was taken, 1.0 g of methyltrimethoxysilane was added, then 0.1 mL of stannous octoate and 0.2 mL of KH550 were added, and the solution was uniformly mixed and kept static for reaction and curing.

A TGA curve of the organic silicone elastomer prepared by this method is as shown in FIG. 1, with a collapse temperature of 350°C.

Example 2 Preparation of high-temperature-resistant organic silicone elastomer by modification of phenyltrimethoxysilane g of methyl-terminated hydroxyl silicone oil with a vis- cosity of 700 cp was taken, 1.5 g of phenyltrimethoxysilane was added, then 0.1 mL of stannous octoate and 0.2 mL of KH550 were added, and the sclution was uniformly mixed and kept static for 15 reaction and curing.

A TGA curve of the organic silicone elastomer prepared by this method is as shown in FIG. 2, with a collapse temperature of 370°C.

Example 3 Preparation of high-temperature-resistant organic silicone elastomer by modification of titanium dioxide nanoparti- cles 10 g of methyl-terminated hydroxyl silicone oil with a vis- cosity of 700 cp was taken, 0.8 g of phenyltrimethoxysilane and 0.2 g of titanium dioxide nanoparticles were added, and the mixed solution was uniformly stirred. Then 0.15 mL of stannous octoate and 0.22 mL of KH550 were added, and the solution was uniformly mixed and kept static for curing.

A TGA curve of the organic silicone elastomer prepared by this method is as shown in FIG. 3, with a collapse temperature of 375°C.

Example 4 Preparation of high-temperature-resistant organic silicone elastomer by modification of titanium dioxide nanoparti- cles 10 g of methyl-terminated hydroxyl silicone oil with a vis- cosity of 700 cp was taken, 0.8 g of phenyltrimethoxysilane and 0.4 g of titanium dioxide nanoparticles were added, and the mixed solution was uniformly stirred. Then 0.12 mL of stannous octoate and 0.25 mL of KH550 were added, and the solution was uniformly mixed and kept static for curing.

A TGA curve of the organic silicone elastomer prepared by this method is shown in FIG. 4, with a collapse temperature of 370°C.

Example 5 Preparation of high-temperature-resistant organic silicone elastomer by titanium-oxo cluster nanoparticles

The specific preparation steps are as follows:

Specifically: 1) 1.05 mmol of propionic acid was mixed with 2 ml of eth- ylene glycol, then 0.5 mmol of titanium isopropoxide was added, the mixed solution was stirred for 5 min, transferred to a pres- sure bottle, sealed, heated and stirred at 100°C for 24 h, and colorless crystal was formed. The crystal was taken out, washed three times with a small amount of anhydrous tetrahydrofuran, and dried in vacuum at room temperature to obtain titanium-oxo cluster nanoparticles. 2) 100 mg of titanium-oxo cluster solid was weighed and placed in a reagent bottle, and 1 mL of dichloromethane was added, ultrasonic treatment was performed until the solid fully dis- solved; the resulting solution was a 100 mg/mL dichloromethane so- lution of titanium-oxo clusters. 3) 10 g of methyl-terminated hydroxyl silicone oil with a viscosity of 700 cp was taken, 1.0 g of phenyltrimethoxysilane and 1 mL of the dichloromethane solution of titanium-oxo clusters were added, and the mixed solution was uniformly stirred. In the re- sulting solution, a mass fraction of the phenyltrimethoxysilane in the hydroxyl silicone oil is 10%, and a mass fraction of the tita- nium-oxo clusters in the hydroxyl silicone oil is 1%. 4) 0.1 mL of stannous octoate and 0.2 mL of KH550 were added to the solution, the solution was uniformly mixed and kept static for reaction and curing.

A TGA curve of the organic silicone elastomer prepared by this method is shown in FIG. 5, with a collapse temperature of 420°C.

Example 6 Preparation of high-temperature-resistant organic silicone elastomer by titanium-oxo cluster nanoparticles

The specific preparation steps are as follows: 1) 100 mg of titanium-oxo cluster solid (prepared through the same process as example 5) was weighed and placed in a reagent bottle, 1 mL of dichloromethane was added, ultrasonic treatment was performed until the solid fully dissolved; the resulting solu- tion was a 100 mg/mL dichloromethane solution of titanium-oxo clusters. 2) 10 g of methyl-terminated hydroxyl silicone oil with a viscosity of 700 cp was taken, 0.8 g of phenyltrimethoxysilane and 1 mL of the solution of titanium-oxo clusters were added, and the mixed solution was uniformly stirred. In the resulting solution, a mass fraction of the phenyltrimethoxysilane in the hydroxyl sili- cone oil is 8%, and a mass fraction of the titanium-oxo clusters in the hydroxyl silicone oil is 13. 3) 0.12 mL of stannous octoate and 0.25 mL of KH550 were add- ed to the solution, and the solution was uniformly mixed and kept static for reaction and curing.

A TGA curve of the organic silicone elastomer prepared by this method is shown in FIG. 6, with a collapse temperature of 395°C.

Example 7 Preparation of high-temperature-resistant organic silicone elastomer by titanium-oxo cluster nanoparticles

The specific preparation steps are as follows: 1) 200 mg of titanium-oxo cluster solid (prepared through the same process as example 5) was weighed and placed in a reagent bottle, 2 mL of dichlorcmethane was added, ultrasonic treatment was performed until the solid fully dissolved; the resulting solu- tion was a 100 mg/mL dichloromethane solution of titanium-oxo clusters. 2) 10 g of methyl-terminated hydroxyl silicone oil with a viscosity of 700 cp was taken, 0.85 g of phenyltrimethoxysilane and 2 mL of the solution of titanium-oxo clusters were added, and the mixed solution was uniformly stirred. In the resulting solu- tion, a mass fraction of the phenyltrimethoxysilane in the hydrox- yl silicone oil is 8%, and a mass fraction of the titanium-oxo clusters in the hydroxyl silicone oil is 2%. 3) 0.1 mL of stannous octoate and 0.2 mL of KH550 were added to the solution, and the solution was uniformly mixed and kept static for reaction and curing.

A TGA curve of the organic silicone elastomer prepared by this method is shown in FIG. 7, with a collapse temperature of 460°C.

Example 8 Preparation of high-temperature-resistant organic silicone elastomer by titanium-oxo cluster nanoparticles

The specific preparation steps are as follows: 1) 400 mg of titanium-oxo cluster solid (prepared through the same process as example 5) was weighed and placed in a reagent bottle, 4 mL of dichloromethane was added, and ultrasonic treat- ment was performed until the solid fully dissolved; the resulting solution was a 100 mg/mL dichloromethane solution of titanium-oxo clusters. 2) 10 g of methyl-terminated hydroxyl silicone oil with a viscosity of 700 cp was taken, 0.8 g of phenyltrimethoxysilane and 4 mL of the solution of titanium-oxo clusters were added, and the mixed solution was uniformly stirred. In the resulting solution, a mass fraction of the phenyltrimethoxysilane in the hydroxyl sili- cone oil is 8%, and a mass fraction of the titanium-oxo clusters in the hydroxyl silicone oil is 4%. 3) 0.15 mL of stannous octoate and 0.25 mL of KH550 were add- ed to the solution, and the solution was uniformly mixed and kept static for reaction and curing.

A TGA curve of the organic silicone elastomer prepared by this method is shown in FIG. 8, with a collapse temperature of 440°C.

The foregoing are only the preferred embodiments of the pre- sent invention, and are not intended to limit the present inven- tion. For those skilled in the art, various changes and variations may be made to the present invention. All modifications, equiva- lent replacements, improvements, etc. made without departing from the spirit and principle of the present invention should fall into the protection scope of the present invention.

Claims

CONCLUSIONS

1. Preparation method of a high-temperature resistant organic silicone elastomer, comprising the following steps: uniformly mixing a hydroxyl silicone oil and a silane monomer crosslinking agent, adding KH550 and tin octoate, and allowing the mixture for static reaction curing, wherein the hydroxyl silicone oil is a methyl-terminated hydroxyl silicone oil; and the silane monomer crosslinking agent is methyltrimethoxysilane or phenyltrimethoxysilane.

A method of preparing a high-temperature resistant organic silicone elastomer according to claim 1, further comprising a step of modifying the organic silicone elastomer by adding titanium dioxide nanoparticles or cyclic titanium oxo cluster molecules Ti::0:¢ (EG) : (PAC).s(EtQ) 1s to the reaction system, where EG stands for ethylene glycol, PAc stands for deprotonated propionic acid and EtO stands for deprotonated ethanol.

The preparation method of a high-temperature resistant organic silicone elastomer according to claim 2, wherein a structural formula of the cyclic titanium oxo cluster molecules Ti32O0:16 (EG)32 (PAC)16 (EtO)16 is as follows: wr | ww md ~ RE my : 4 L Dr hed >” mea i Le Ss, Leda RET Le MAA ey an} ae? et di ek et Dn MCL Yt, By Dd Ne Vb el - Tw Ny SONA Ag A Les El yd Lay STN NS ee | > SOEs Coal Jee NT en ' VT XD ET Vi ket dd A] ee EL A] ee NL TNT ee De | AS of A 1 \, ng / dr ON í CAT dee fo PLN Nd ER Oan AEL ANT EE Len le \ i KF % Fi “nobility AEs ee YT Fas mene TT ANE TT A eN TIT pee ST LY a EET ESV RAY SE BLN Lag ee Vr a ST TE see ESTING \ ne po eN \ ee TT Ta ANA TTT 3 ch be sor ==

The preparation method of a high temperature resistant organic silicone elastomer according to claim 3, wherein the cyclic titanium oxo cluster molecules are added in a form of a dichloromethane solution of cyclic titanium oxo clusters; or wherein a method of preparation of the cyclic titanium oxo cluster molecules Ti320:15(EG)}3:2(PAc)is (EtO)1s comprises the following steps: adding titanium isopropoxide to a mixed solution of propionic acid and ethylene glycol , uniformly mixing, sealing, heating and stirring the solution at 90 to 110 °C for 20 to 30 hours to form the cyclic titanium oxo cluster molecules Ti320:6 (EG) 32 (PAC) 5 (EEO); to obtain.

The production method of a high-temperature resistant organic silicone elastomer according to claim 1, wherein a viscosity of the methyl-terminated hydroxyl silicone oil is 650 to 750 cP.

The preparation method of a high-temperature resistant organic silicone elastomer according to claim 2, wherein the titanium dioxide nanoparticles are P25 type with an average particle diameter of 25 nm.

The preparation method of a high-temperature resistant organic silicone elastomer according to claim 1, wherein the silane monomer crosslinking agent is phenyltrimethoxysilane.

The preparation method of a high temperature resistant organic silicone elastomer according to claim 1, wherein a molar ratio of the hydroxyl silicone oil, the silane monomer crosslinking agent, KH550 and the tin octoate is 1040:15-25:2-4:0, 8-1.2; or wherein a mass of the titanium dioxide nanoparticles is 2 to 4% that of the hydroxyl silicone oil; wherein a mass of the cyclic titanium oxo clusters is 1 to 4% that of the hydroxyl silicone oil.

The preparation method of a high-temperature resistant organic silicone elastomer according to claim 1, wherein a static reaction curing temperature is 20 to 30°C.

A high temperature resistant organic silicone elastomer prepared by the preparation method according to any one of claims 1 to 9.