CN1281661C - Alkynyl-containing poly-siloxane and method for preparing same - Google Patents

Abstract

The invention relates to an alkynyl-containing polysilazane, which has the following structure:

SiR ₁ R ₂ C≡C-SiR ₁ R ₂  _n NH _m

Wherein, R ₁ and R ₂ are alkyl, alkenyl, phenyl or H with 1 to 6 carbon atoms; n=1 to 10, m=10 to 100, and m and n are positive integers. The alkynyl-containing polysilazane provided by the present invention is prepared by the ammonolysis method of alkynyl-containing chlorosilane, has good thermal stability and photoelectric function, and can be used as a ceramic precursor and a photoelectric material with high heat resistance .

Description

A kind of polysilazane containing alkyne group and preparation method thereof

technical field

The invention relates to a polysilazane and a preparation method thereof.

Background technique

In recent years, studies on conjugated polymers have attracted attention. Due to their unique electronic structure, they have some special properties, such as optoelectronic properties, which can be made into large-area flat-panel displays and light-emitting diodes, conductive coatings, chemical and biological sensors, nonlinear optical materials, light-emitting materials and batteries, etc. (Burroughes, J.H.; Brown, A.R.; Marks, R.N.Nature 1990, 347, 539), the introduction of organosilicon groups into the conjugated backbone can improve the performance of conjugated polymers: for example, the introduction of silicon in styrene polymers , a blue shift can be observed, which changes its optical properties; the introduction of organosilicon groups into the conjugated backbone can also improve the solubility of the polymer and the processability of the material.

Alkyne-containing organosilicon conjugated polymers have unique electrical and optical properties due to the electron delocalization system formed by the π electrons on the alkyne group and Si atoms. (Giseopo, K.; Toshio, M. Macromolecules 2002, 35, 4138) In addition, the thermal stability of the polymer is also improved due to the introduction of the alkynyl group. (Nishihara, Y.; Ando, J.; Mori, A. Macromolecules 2000, 33, 2779; Oshita, J.; Shinpo, A.; Kunai, A. Macromolecules 1999, 32, 5998; Itoh, M.; Inonue, K.; Iwata, K.; Mitsuzuka, M.; Kakigana, T. Macromolecules 1997, 30, 694). Therefore, this type of silyne-containing organosilicon conjugated polymer can be used as a semiconductor material, an optoelectronic material, a ceramic precursor, and a high temperature resistant elastomer. For example, introducing silynyl groups into siloxane polymers can obtain a linear polymer material with high temperature resistance, good flexibility and processability. (Marc, B., Paul, P J.; Jacques, D. Chem Rev 1995, 95, 1443-1477; Armistead, J.P.; Houser, E.J.; Keller, T.M. Appl Organometal Chem. 2000, 14, 253; Noriyoshi, M .; Yoshi, C. Polymer Journal 2001, 33, 383.)

Most of the alkynyl-containing organosilicon conjugated polymers reported in the literature are silicon-carbon and silicon-oxygen polymers, and silicon-nitrogen polymers have not been reported yet. Therefore, we envisage introducing ethynyl groups into silazane to synthesize alkynyl-containing In polysilazanes, the lone pair of electrons on the N atom and the π electrons of the silyne system form a large electron delocalization system, which may exhibit new optical properties and electrical conductivity. Moreover, this type of polymer has a rigid chain structure and can also be used as a ceramic precursor. On the one hand, it is beneficial to spinning, and on the other hand, it can be used as a reactive group to generate crosslinking under heat. The silicon carbon fiber prepared by the existing literature method It is cross-linked by oxidation, so it is beneficial to improve the ceramic yield and thermal stability; the main chain contains both Si-C bonds and Si-N bonds, which can make the precursor cracking products contain both SiC and Si ₃ N ₄ Composition, forming a multiphase ceramic with better toughness; in addition, the synthesized precursor is a linear polymer, soluble/fusible, and has good processing and storage properties before its crosslinking.

Contents of the invention

The object of the present invention is to provide an alkynyl-containing polysilazane and a preparation method thereof. The synthesized alkynyl-containing polysilazane has good thermal stability and photoelectric function, and can be used as a ceramic precursor with high durability. thermal optoelectronic materials.

The structure of a kind of alkyne-containing polysilazane provided by the present invention can be expressed as:

SiR ₁ R ₂ C≡C-SiR ₁ R ₂  _n NH _m

in,

R ₁ and R ₂ are alkyl, alkenyl, phenyl or H with 1 to 6 carbon atoms; preferably R ₁ and R ₂ are the same as methyl,

R ₁ and R ₂ are both phenyl, R ₁ is methyl, R ₂ is H, R ₁ is methyl, R ₂ is vinyl, or R ₁ is methyl and R ₂ is phenyl.

n=1-10, m=10-100, m and n are positive integers.

The preparation method and steps of polysilazane containing alkyne group of the present invention are as follows:

1) Under the protection of _N2 , the solution of trichlorethylene and organic solvent (the weight ratio of trichlorethylene and organic solvent is 1:10) was added dropwise to the solution of butyllithium (n-BuLi) and organic solvent (butyl The weight ratio of base lithium to organic solvent is 1:2), and stirred and reacted at -78°C for 12 hours to obtain a white turbid liquid of acetylene lithium.

2) Under the protection of N ₂ , the white turbid liquid of lithium acetylene was slowly added dropwise under stirring to diorganodichlorosilane (Me ₂ SiCl ₂ , MeHSiCl ₂ , MeViSiCl ₂ , MePhSiCl ₂ , Ph ₂ SiCl ₂ ) and organic solvent solution (weight ratio of diorganodichlorosilane to organic solvent: 1:2~10), stirred and reacted at -30~20°C for 10~20 hours, the system was allowed to stand for stratification, and the supernatant was transferred out and used The organic solvent is washed 3 to 6 times, the filtrates are combined, and the solvent is removed under reduced pressure to obtain an alkynyl-containing chlorosilane oligomer.

3) Add the alkynyl-containing chlorosilane oligomer into an organic solvent to dissolve (the weight ratio of the alkynyl-containing chlorosilane oligomer to the organic solvent is 1:10-50), feed ammonia gas, and carry out the ammonolysis reaction, at 20-140 After stirring for 10 to 36 hours at ℃, the system was left to stand and separated, the supernatant was transferred out, the precipitate was washed 3-6 times with an organic solvent, the filtrate was combined, and the solvent was removed under reduced pressure to obtain an alkyne group-containing compound with a linear structure. Polysilazane.

The alkyne group-containing polyazane provided by the present invention is determined by gel permeation chromatography, and n=1-10, m=10-100.

The alkyne group-containing polyazane provided by the invention has good thermal stability and photoelectric function, and can be used as a ceramic precursor and a photoelectric material with high heat resistance.

Detailed ways

Example 1

In a 250ml three-necked flask, add 50ml tetrahydrofuran, 50ml diethyl ether and 50ml (n-BuLi, 2.5mol/L), under the protection of _N2 , slowly drop the mixed solution of 36ml diethyl ether and 3.6ml trichlorethylene at -78°C into the mixed solution in the three-neck flask. After the dropwise addition, the stirring was continued for 12 hours to obtain a white cloudy liquid of lithium acetylene.

Add 20 ml of ether and 0.1 mol of Me ₂ SiCl ₂ into a 500 ml three-necked flask, and slowly drop in the cloudy lithium acetylene solution under the protection of N ₂ . After the dropwise addition was completed, stirring was continued at -30°C for 10 hours, and then left to settle. The system was layered, the upper layer was a light yellow clear liquid, and the lower layer was a white precipitate. Under the protection of N ₂ , the supernatant liquid was pressed into a clean and dry three-neck flask with glass sand core under the protection of N ₂ , and the precipitate was washed three times with ether. Combine the filtrates. The solvent was removed from the filtrate under reduced pressure to obtain the alkynyl-containing chlorosilane oligomer as light yellow viscous liquid with a yield of 97%.

Dissolve 2 g of alkynyl-containing chlorosilane oligomers in 20 ml of toluene, and react with ammonia gas for 10 hours at 20° C. under stirring until the system no longer absorbs ammonia gas, and then pass ammonia for 2 hours. After standing and settling, the supernatant was transferred to another three-neck flask, the precipitate was washed six times with toluene, the filtrates were combined, and the solvent was distilled off to obtain a yellow viscous liquid with a yield of 85%.

Characterization of alkyne-containing chlorosilane oligomers:

²⁹ Si-NMR (ppm): -0.6 (Cl-SiMe ₂ ), -40.0 (C≡C-SiMe ₂ -C≡C);

¹³ C-NMR (ppm); 1.0 (Si-CH ₃ ), 112 (C≡C).

Characterization of alkyne-containing polysilazanes:

Mw=9000, Mw/Mn=2.4;

²⁹ Si-NMR (ppm): -16.7, -18.4 (HN-SiMe ₂ ), -40.5 (C≡C-SiMe ₂ -C≡C); compared with the alkynyl-containing chlorosilane oligomer before ammonolysis, The shift of Si-Cl disappeared at -0.6ppm, and new shift peaks appeared at -16.7, -18.4ppm, indicating that the Si-Cl bond of the alkynyl-containing chlorosilane oligomer was replaced by Si-NH bond.

FTIR (cm ^-1 ): 2148 (v _C≡C ), 3303, 1190 (v _NH ), 930 (v _Si-NH );

Elemental analysis (mass%):

Calculated: C, 53.86; H, 7.93; N, 3.49;

Found: C, 52.53; H, 7.93; N, 3.20.

The obtained alkyne-containing polysilazane was subjected to thermogravimetric analysis using a thermogravimetric analyzer, with a heating rate of 10°C/min, _Tonset : 320°C, and residual weight at 1000°C: 60%.

The sample was dissolved in THF to make a 0.5mmol/L solution, which was analyzed by fluorescence emission spectrum using a F4500 fluorescence spectrometer. Its maximum fluorescence emission peak is at 310nm.

Example 2

Add 50 ml of ether and 0.2 mol of MePhSiCl ₂ into a 500 ml three-necked flask, and slowly drop in the cloudy lithium acetylene solution under the protection of N ₂ . After the dropwise addition was completed, stirring was continued at 20° C. for 20 hours, and then left to settle. The system was layered, the upper layer was a light yellow liquid, and the lower layer was a white precipitate. Under the protection of _N2 , the supernatant was hydraulically poured into a clean and dry three-neck flask with a glass sand core, and the precipitate was washed six times with ether. Combine the filtrates. The solvent was removed from the filtrate under reduced pressure to obtain the alkynyl-containing chlorosilane oligomer as a yellow viscous liquid with a yield of 93%.

Characterization of alkyne-containing chlorosilane oligomers:

²⁹ Si-NMR (ppm): -10.0 (Cl-SiMePh), -44.0 (C≡C-SiMePh-C≡C).

2 g of alkynyl-containing chlorosilane oligomers were dissolved in 50 ml of xylene, stirred and reacted for 36 hours at 140° C. with ammonia gas until the system no longer absorbed ammonia gas, and then passed through ammonia for 2 hours. After standing and settling, the supernatant was transferred to another three-necked flask, the precipitate was washed three times with toluene, the filtrates were combined, and the solvent was distilled off to obtain a brownish-yellow solid with a yield of 71%.

Characterization of alkyne-containing polysilazanes:

Mw=3900, Mw/Mn=1.4;

²⁹ Si-NMR (ppm): -25.0 (HN-SiMePh), -44.0 (C≡C-SiMePh-C≡C);

FTIR (cm ^-1 ): 2145 (v _C≡C ), 3300, 1185 (v _NH ), 927 (v _Si-NH ), 3060 (v _{phenyl CH} ).

The obtained alkyne-containing polysilazane was subjected to thermogravimetric analysis using a thermogravimetric analyzer, with a heating rate of 10°C/min, _Tonset : 390°C, and residual weight at 1000°C: 69%.

The sample was dissolved in THF to make a 0.5mmol/L solution, which was analyzed by fluorescence emission spectrum using a F4500 fluorescence spectrometer. Its maximum fluorescence emission peak is at 360nm.

Example 3

Add 100 ml of ether and 0.1 mol Ph ₂ SiCl ₂ into a 500 ml three-necked flask, and slowly drop in the cloudy lithium acetylene solution under the protection of N ₂ . After the dropwise addition was completed, stirring was continued at 0° C. for 12 hours, and the mixture was left to settle. The system was layered, the upper layer was orange clear liquid, and the lower layer was pink precipitate. Under the protection of _N2 , the supernatant liquid was pressed into a clean and dry three-neck flask with glass sand core under the protection of _N2 , and the precipitate was washed four times with ether. Combine the filtrates. The solvent was removed from the filtrate under reduced pressure to obtain the alkynyl-containing chlorosilane oligomer as a brown viscous liquid with a yield of 91%.

Characterization of alkyne-containing chlorosilane oligomers:

²⁹ Si-NMR (ppm): -20.0 (Cl-SiPh ₂ ), -49.0 (C≡C-SiPh ₂ -C≡C).

Dissolve 1 g of alkynyl-containing chlorosilane oligomer in 50 ml of benzene, and pass ammonia gas at 80° C. for 20 hours to react with stirring until the system no longer absorbs ammonia gas, and then pass ammonia for 2 hours. After standing and settling, the supernatant was transferred to another three-neck flask, the precipitate was washed four times with toluene, the filtrates were combined, and the solvent was distilled off to obtain an orange-red solid with a yield of 70%.

Characterization of alkyne-containing polysilazanes:

Mw=3000, Mw/Mn=1.4;

²⁹ Si-NMR (ppm): -37.0, -38.5 (HN-SiPh ₂ ), -49.0 (C≡C-SiPh ₂ -C≡C);

FTIR (cm ^-1 ): 2144 (v _C≡C ), 3296, 1184 (v _NH ), 936 (v _Si-NH ), 3055 (v _{phenyl CH} ).

The obtained alkyne-containing polysilazane was subjected to thermogravimetric analysis using a thermogravimetric analyzer, the heating rate was 10°C/min, the _Tonset : 447°C, and the residual weight at 1000°C: 75%.

The sample was dissolved in THF to make a 0.5mmol/L solution, which was analyzed by fluorescence emission spectrum using a F4500 fluorescence spectrometer. Its maximum fluorescence emission peak is at 397m.

Example 4

Add 150 ml of ether and 0.2 mol of MeHSiCl ₂ into a 500 ml three-necked flask, and slowly drop in the cloudy lithium acetylene solution under the protection of N ₂ . After the dropwise addition was completed, stirring was continued at 0° C. for 12 hours, and then left to settle. The system was layered, the upper layer was a light yellow clear liquid, and the lower layer was a white precipitate. Under the protection of N ₂ , the supernatant liquid was pressed into a clean and dry three-neck flask with glass sand core under the protection of N ₂ , and the precipitate was washed three times with ether. Combine the filtrates. The solvent was removed from the filtrate under reduced pressure to obtain the alkynyl-containing chlorosilane oligomer as a yellow viscous liquid with a yield of 95%.

2 g of alkynyl-containing chlorosilane oligomers were dissolved in 100 ml of toluene, stirred and reacted at 110° C. for 36 hours with ammonia gas until the system no longer absorbed ammonia gas, and then passed with ammonia for 2 hours. After standing and settling, the supernatant was transferred to another three-neck flask, the precipitate was washed three times with toluene, the filtrates were combined, and the solvent was distilled off to obtain a yellow solid with a yield of 85%.

Characterization of alkyne-containing polysilazanes:

Mw=10000, Mw/Mn=2.7;

FTIR (cm ^-1 ): 2140 (v _C≡C ), 3292, 1184 (v _NH ), 939 (v _Si-NH ), 2200 (v _Si-H ).

The obtained alkyne-containing polysilazane was subjected to thermogravimetric analysis with a thermogravimetric analyzer, the heating rate was 10°C/min, the _Tonset : 300°C, and the residual weight at 1000°C: 80%.

Example 5

Add 300 ml of ether and 0.3 mol of MeViSiCl ₂ into a 500 ml three-necked flask, and slowly drop in the cloudy lithium acetylene solution under the protection of N ₂ . After the dropwise addition was completed, stirring was continued at 0° C. for 12 hours, and the mixture was left to settle. The system was layered, the upper layer was a light yellow clear liquid, and the lower layer was a white precipitate. Under the protection of N ₂ , the supernatant liquid was pressed into a clean and dry three-neck flask with glass sand core under the protection of N ₂ , and the precipitate was washed three times with ether. Combine the filtrates. The solvent was removed from the filtrate under reduced pressure to obtain ethynylchlorosilane oligomer as a yellow viscous liquid with a yield of 90%.

Characterization of alkyne-containing chlorosilane oligomers:

²⁹ Si-NMR (ppm): -13.0 (Cl-SiMeVi), -48.0 (C≡C-SiMeVi-C≡C).

Dissolve 0.5 of the alkynyl-containing chlorosilane oligomer in 25 ml of toluene, and react with ammonia gas at 110° C. for 24 hours with stirring until the system no longer absorbs ammonia gas, and then pass ammonia for 2 hours. After standing and settling, the supernatant was transferred to another three-neck flask, the precipitate was washed three times with toluene, the filtrates were combined, and the solvent was distilled off to obtain an orange solid with a yield of 75%.

Characterization of alkyne-containing polysilazanes:

Mw=1000, Mw/Mn=1.2;

²⁹ Si-NMR (ppm): -28.0 (HN-SiMeVi), -48.0 (C≡C-SiMeVi-C≡C).

The obtained alkyne-containing polysilazane was subjected to thermogravimetric analysis using a thermogravimetric analyzer, with a heating rate of 10°C/min, _Tonset : 350°C, and residual weight at 1000°C: 71%.

The sample was dissolved in THF to make a 0.5mmol/L solution, which was analyzed by fluorescence emission spectrum using a F4500 fluorescence spectrometer. Its maximum fluorescence emission peak is at 330nm.

Example 6

Add 50 ml of ether and 0.1 mol of MeViSiCl ₂ into a 500 ml three-necked flask, and slowly drop in the cloudy lithium acetylene solution under the protection of N ₂ . After the dropwise addition was completed, stirring was continued at 0° C. for 12 hours, and then left to settle. The system was layered, the upper layer was a light yellow clear liquid, and the lower layer was a white precipitate. Under the protection of _N2 , the supernatant was poured into a clean and dry three-neck flask with _N2 using a glass sand core, and the precipitate was washed three times with ether. Combine the filtrates. The solvent was removed from the filtrate under reduced pressure to obtain the alkynyl-containing chlorosilane oligomer as a yellow viscous liquid with a yield of 90%.

Add 1g (NH ₄ ) ₂ SO ₄ to a 250ml three-necked flask, heat to remove water with N ₂ , dissolve 2g of alkynyl-containing chlorosilane oligomer in 100ml toluene, add it to the three-necked flask, and pass ammonia gas at 110°C Stir the reaction for 20 hours until the system no longer absorbs ammonia, then pass ammonia for another 2 hours. After standing and settling, the supernatant was transferred to another three-neck flask, the precipitate was washed three times with toluene, the filtrates were combined, and the solvent was distilled off to obtain an orange solid with a yield of 76%.

Characterization of alkyne-containing polysilazanes:

Mw=45000, Mw/Mn=1.6;

²⁹ Si-NMR (ppm): -28.0 (HN-SiMeVi), -48.0 (C≡C-SiMeVi-C≡C).

The obtained alkyne-containing polysilazane was subjected to thermogravimetric analysis using a thermogravimetric analyzer, with a heating rate of 10°C/min, _Tonset : 360°C, and residual weight at 1000°C: 71%.

The sample was dissolved in THF to make a 0.5mmol/L solution, which was analyzed by fluorescence emission spectrum using a F4500 fluorescence spectrometer. Its maximum fluorescence emission peak is at 343nm.

Claims (3)

1. An alkynyl-containing polysilazane, characterized in that the alkynyl-containing polysilazane has the following structure:

in, R ₁ and R ₂ are alkyl, alkenyl, phenyl or H with 1 to 6 carbon atoms; n=1-10, m=10-100, m and n are positive integers. 2. The preparation method of the alkynyl-containing polysilazane according to claim 1, characterized in that it is carried out according to the following steps: 1) Under the protection of _N2 , mix and dissolve trichlorethylene and organic solvent at a weight ratio of 1:10, and then add dropwise to the solution of butyllithium and organic solvent at a weight ratio of 1:2, at -78°C Under stirring reaction 12 hours, obtain acetylene lithium white turbid liquid, 2) Under the protection of N ₂ , the white turbid liquid of lithium acetylene was slowly added dropwise under stirring to the diorganodichlorosilane Me ₂ SiCl ₂ , MeHSiCl ₂ , MeViSiCl ₂ , MePhSiCl ₂ or Ph ₂ SiCl ₂ respectively mixed with the organic solvent according to In a mixed solution with a weight ratio of 1:2-10, stir and react at -30-20°C for 10-20 hours, then let the system stand for stratification, transfer the supernatant, and wash the precipitate with an organic solvent for 3-6 times. The filtrates were combined, and the solvent was removed under reduced pressure to obtain an alkynyl-containing chlorosilane oligomer, 3) Synthesis of alkyne-containing polysilazane After mixing and dissolving the alkynyl-containing chlorosilane oligomer and the organic solvent in a weight ratio of 1:10-50, the ammonia gas is introduced to carry out the ammonolysis reaction, and the reaction is stirred at 20-140°C for 10-36 hours, and the system is static After layering, the supernatant is transferred out, the precipitate is washed 3-6 times with an organic solvent, the filtrate is combined, and the solvent is removed under reduced pressure to obtain an alkynyl-containing polysilazane. 3. The preparation method of polysilazane containing alkyne group according to claim 2, characterized in that said organic solvent is an aromatic hydrocarbon with 6-8 carbon atoms, tetrahydrofuran, diethyl ether or their mixed solvents.