A modified tetraphenylacetylene silane resin prepolymer and a preparation method thereof

Abstract

The application discloses a modified tetraphenyl ethynyl silane resin prepolymer and a preparation method thereof. Specifically, the application discloses a modified tetraphenyl ethynyl silane resin prepolymer which is a three-dimensional network structure and has a repeating structural unit as shown in the following formula.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic synthesis high polymer materials, and in particular, the present application relates to a modified tetraphenylacetylene silane resin prepolymer and a preparation method thereof. BACKGROUND

[0002] With the rapid development of aerospace technology in recent years, the demand for high-speed aircraft technology, the demand for polymer materials is higher, and pure high molecular organic material can not meet the complex application requirements today. Organic-inorganic hybrid technology provides a new way for the design, preparation and application of high-performance polymer materials. The organic-inorganic hybrid material prepared by introducing inorganic elements into the polymer structure has excellent performance.

[0003] The most typical silicon-silicon resin is a silicon-silicon resin containing silicon hydrogen bond. The resin has good processing property, no by-product is generated during curing reaction, and shows excellent properties such as high temperature resistance, low dielectric constant and high temperature ceramicization, which can be applied to high-temperature resistant, ablation resistant, wave-transparent and ceramic materials. Silicon-silicon resin can be self-cured at high temperature, and the structure of-C=C-C=C- is formed by silicon hydrogen addition reaction or the naphthalene ring structure is formed by Diels-Alder reaction. Silicon-silicon resin can be prepared into high-performance composite material with glass fiber, which has good thermal performance and dielectric performance, but due to its high curing temperature, it usually needs to be carried out at more than 350 DEG C, and complete curing needs high temperature of more than 400 DEG C, which has many limitations for molding process and application scene, and the energy consumption is also relatively high. Pure silicon-silicon hybrid resin is difficult to meet the requirements of modern molding process, so other ways are needed to further reduce its curing temperature and energy consumption.

[0004] Therefore, it is urgent to develop a silicon-silicon resin with lower curing temperature and excellent physical properties in the field. SUMMARY

[0005] An object of the present application is to provide a modified tetraphenylacetylene silane resin prepolymer with low curing temperature and excellent physical properties.

[0006] In the first aspect of the present application, a modified tetraphenylacetylene silane resin prepolymer is provided, which is prepared from tetraphenylacetylene silane and sylvanone; the prepolymer has a three-dimensional network structure and has a repeating structural unit as shown below:

[0007]

[0008] wherein R represents phenyl,

[0009] the silicon atom is represents a linking structure omitted for the site, and the site is a structure resulting from reaction of the ethynyl group in the phenylethynyl group or the ethynyl group in the phenylethynyl group with the five-membered heterocyclic moiety in the sydnone.

[0010] In another preferred embodiment, the pre-polymer has a number average molecular weight Mn of 4000-6000; and / or a weight average molecular weight Mw of 7000-9000.

[0011] In another preferred embodiment, the pre-polymer has a number average molecular weight Mn of 5000-6000; and / or a weight average molecular weight Mw of 8000-9000.

[0012] In another preferred embodiment, the pre-polymer has a number average molecular weight Mn of 5235; and / or a weight average molecular weight Mw of 8907.

[0013] In a second aspect of the present application, there is provided a method for preparing the modified tetraphenyl ethynyl silane resin pre-polymer of the first aspect of the present application, comprising the steps of:

[0014] reacting the sydnone with the tetraphenyl ethynyl silane in an organic polar solvent to obtain the modified tetraphenyl ethynyl silane resin pre-polymer.

[0015] In another preferred embodiment, the reaction temperature is 120-180°C; preferably 140-180°C; more preferably 160-180°C.

[0016] In another preferred embodiment, the reaction time is 2-12h; preferably 4-8h.

[0017] In another preferred embodiment, the sydnone has a structure selected from the group consisting of:

[0018]

[0019] In another preferred embodiment, the molar ratio of the tetraphenyl ethynyl silane to the sydnone is 1:(1.5-2.5); preferably 1:2.

[0020] In another preferred embodiment, the organic polar solvent is selected from the group consisting of N,N-dimethylformamide, N-methyl pyrrolidone, N,N-dimethylacetamide, or a combination thereof; preferably N-methyl pyrrolidone.

[0021] In another preferred embodiment, the mass ratio of the tetraphenyl ethynyl silane to the organic polar solvent is 1:(15-20).

[0022] In another preferred embodiment, the method comprises:

[0023] The tetraphenyl ethynyl silane and Sydney ketone are dissolved in a polar organic solvent under inert gas protection in a molar ratio of 1: (1.5-2.5) at 120-180°C for 2-12h to obtain the modified tetraphenyl ethynyl silane resin prepolymer.

[0024] In another preferred embodiment, the reaction is accompanied by stirring.

[0025] In another preferred embodiment, the reaction further comprises: after the reaction is completed, cooling to room temperature (15-35°C), adding a precipitant to the reaction solution to precipitate the solid, which is the modified tetraphenyl ethynyl silane resin prepolymer.

[0026] In another preferred embodiment, the precipitant is water, C1-C6 alcohol solvent, or a combination thereof; preferably one or more of water, methanol, ethanol; more preferably methanol.

[0027] In another preferred embodiment, the method further comprises post-treatment: filtering the precipitated solid, washing, and drying.

[0028] In another preferred embodiment, the washing is washing with water and / or ethanol.

[0029] In another preferred embodiment, the washing is multiple times (for example, 2, 3, or 4 times).

[0030] In a third aspect of the present application, a cured product of the modified tetraphenyl ethynyl silane resin prepolymer of the first aspect of the present application is provided, wherein the cured product is obtained by curing the modified tetraphenyl ethynyl silane resin prepolymer of the first aspect of the present application.

[0031] In another preferred embodiment, the curing is temperature gradient curing.

[0032] In another preferred embodiment, the temperature gradient curing is 200°C / 2h + 220°C / 2h + 250°C / 2h + 280°C / 5h.

[0033] In another preferred embodiment, the temperature gradient curing is 200°C / 2h + 220°C / 2h + 250°C / 2h + 300°C / 5h.

[0034] In another preferred embodiment, the Td of the cured product under nitrogen atmosphere is 400-458°C; the Td under air atmosphere is 405-445°C. d5 In another preferred embodiment, the Td of the cured product under nitrogen atmosphere is 400-458°C; the Td under air atmosphere is 405-445°C. d5

[0035] In another preferred embodiment, the Td of the cured product under nitrogen atmosphere is 400-458°C; the Td under air atmosphere is 405-445°C. d5 In another preferred embodiment, the Td of the cured product under nitrogen atmosphere is 400-458°C; the Td under air atmosphere is 405-445°C. d5

[0036] ​​In another preferred embodiment, the retention rate of the cured product of the sila-hybrid resin under nitrogen atmosphere at 1000°C is 55-73%; the retention rate of the sila-hybrid resin under air atmosphere at 1000°C is 15-46%.

[0037] Preferably, the retention rate of the cured product of the sila-hybrid resin under nitrogen atmosphere at 1000°C is 69-73%; the retention rate of the sila-hybrid resin under air atmosphere at 1000°C is 38-46%.

[0038] In a fourth aspect of the present application, there is provided an article comprising the cured product of the modified tetraphenylacetylene silane resin prepolymer of the first aspect of the present application.

[0039] In another preferred embodiment, the proportion of the cured product of the modified tetraphenylacetylene silane resin prepolymer of the first aspect of the present application in the article is ≥ 1%; preferably ≥ 10%, ≥ 20%, ≥ 30%, ≥ 40%, ≥ 50%, ≥ 60%, ≥ 70%, ≥ 80%, ≥ 90%, ≥ 95%, ≥ 99%.

[0040] It should be understood that, within the scope of the present application, the above technical features of the present application and the technical features specifically described hereinafter (e.g. in the examples) can be combined with each other to form new or preferred technical solutions. Due to the limited space, they will not be listed one by one here. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The infrared spectrum of tetraphenylacetylene silane is shown;

[0042] Figure 2 The nuclear magnetic hydrogen spectrum of tetraphenylacetylene silane is shown;

[0043] Figure 3 The infrared spectrum of 3,3'-(1,4-phenyl) disilyl ketone is shown;

[0044] Figure 4 The nuclear magnetic hydrogen spectrum of 3,3'-(1,4-phenyl) disilyl ketone is shown;

[0045] Figure 5 The infrared spectrum of the modified tetraphenylacetylene silane resin is shown;

[0046] Figure 6 The GPC of the modified tetraphenylacetylene silane resin prepolymer is shown;

[0047] Figure 7 The DSC spectrum of tetraphenylacetylene silane prepolymer before and after modification is shown. DETAILED DESCRIPTION

[0048] The inventors first introduce sylvone into the structure of silaalkyne, and obtain a modified tetraphenylacetylene silane resin prepolymer with a curing temperature lower than 280 DEG C through extensive and in-depth research. Specifically, the present application prepares a silaalkyne resin prepolymer containing a heterocyclic structure by carrying out a cycloaddition reaction of sylvone and tetraphenylacetylene silane resin, thereby greatly reducing the curing temperature and energy consumption and improving the processing performance. Based on this, the inventors complete the present application.

[0049] Terms

[0050] As used herein, the term "room temperature" refers to 0-40 DEG C, preferably 15-35 DEG C.

[0051] Sylvone

[0052] Sylvone is an interionic compound with the properties of 1,3-dipole, which can undergo a dipole cycloaddition reaction with unsaturated compounds such as alkenes and alkynes. Sylvone compound is a five-membered heterocyclic compound composed of O(1)-N(2)-N(3)C(4)-C(5), which belongs to non-benzene aromatic system. The charge distribution of each atom on the ring of the compound is quite special, which cannot be represented by a single covalent structure, making its reaction unique.

[0053] Specifically, the sylvone catalyst provided by the present application has the following structure:

[0054]

[0055] Modified tetraphenylacetylene silane resin prepolymer and preparation method thereof

[0056] Most of the curing of silaalkyne resin relies on the self-curing reaction of triple bond, and the structure has uncertainty, and the steric hindrance of acetylene group in the structure is great. By adding sylvone, a new heterocyclic structure can be introduced, the structure is accurate, and the curing temperature is greatly reduced and the crosslinking degree is improved. Based on this, the inventors design and develop a preparation method of a modified silaalkyne resin prepolymer with low-temperature curing, and the obtained cured product has good heat resistance, which provides convenience for preparing high-performance composite materials.

[0057] Tetraphenylacetylene silane resin

[0058] Specifically, the present application prepares a low-temperature curing resin by reacting bifunctional sylvone with tetraphenylacetylene silane resin. Through cycloaddition reaction, a heterocyclic structure is formed, which greatly reduces the curing temperature and energy consumption required for complete curing of the resin, and the prepolymer is suitable for various molding processes.

[0059] The modified tetraphenylacetylene silane resin prepolymer of the present application has

[0060]

[0061] In particular, the present application provides a method for preparing the modified tetraphenylacetylene silane resin prepolymer as described above, comprising the following steps:

[0062] In an inert atmosphere, the sylvan and the tetraphenylacetylene silane resin are reacted in an organic polar solvent at 120-180°C for 2-12h; after the reaction is completed, it is cooled to room temperature, the reaction solution is added to the precipitant, and the product is precipitated to obtain the prepolymer of the low-temperature curing modified silicane resin.

[0063] In the present application, the sylvan and the tetraphenylacetylene silane resin can be reacted at any temperature between 120-180°C to obtain the prepolymer, for example, 120°C, 130°C, 140°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, etc.

[0064] In the present application, the inert gas used is not particularly limited, and is the inert gas commonly used in the art, for example, nitrogen, argon, etc.

[0065] In the present application, the reaction time is not particularly limited, and can be any time within 2-12h, and the reaction can occur; for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0066] In the present application, the post-treatment of the reaction is a conventional post-treatment step, including: filtration to collect the solid, (multiple) washing, (vacuum) drying, etc.

[0067] In the present application, the organic polar solvent refers to a solvent molecule that has a polar bond, and is a polar molecule, so that these molecules have electrical polarity. The organic polar solvent suitable for the present application includes amide solvents, pyrrolidone solvents, etc.; for example: N,N-dimethylformamide, N-methyl pyrrolidone, N,N-dimethylacetamide, etc.

[0068] In the present application, the precipitant refers to a liquid that precipitates the prepolymer from the solution, for example, water or an alcohol solvent.

[0069] In one embodiment, the phenyl group on the tetraphenylacetylene silane resin in the reaction can be optionally substituted with a group selected from the group consisting of halogen, cyano, amino, hydroxyl, C1-C3 alkyl, halogenated C1-C3 alkyl, C1-C3 hydroxyalkyl.

[0070] The melting point of tetraphenylacetylene silane is relatively high, and it cannot be completely cured at 400°C. After modification, the melting point of the tetraphenylacetylene silane resin is significantly reduced, and it can be completely cured at a lower temperature subsequently, without the need for high-temperature post-treatment.

[0071] The modified tetraphenylacetylene silane resin prepolymer obtained by the method of the present application has a prepolymerization temperature lower than 200 DEG C, while the curing temperature of the silane in the art is generally higher than 350 DEG C, and the curing temperature of the modified prepolymer of the present application is lower than 300 DEG C. The modified method of the present application is significantly lower than the prepolymerization temperature, realizes low-temperature curing, reduces energy consumption, and the cured product structure obtained by the curing has high precision, high yield, simple processing process, low curing temperature, and can be widely applied to the fields of electronic industry, aerospace, high-performance composite materials, etc.

[0072] Compared with the prior art, the main advantages of the present application include:

[0073] (1) The present application first modifies the silane resin with Sydney ketone.

[0074] (2) The Sydney ketone modified silane resin prepolymer of the present application has a lower prepolymerization temperature and curing temperature, and the curing temperature is lower than 300 DEG C; energy consumption is reduced.

[0075] (3) The present application provides a preparation method of a novel low-temperature curing modified silane resin prepolymer, compared with the traditional curing temperature of silane resin above 400 DEG C, the prepolymer of the present application breaks through the high steric hindrance of the ethynyl group in the tetraphenylacetylene silane, and can be cured and formed at a lower temperature, reduces energy consumption, and is suitable for various molding processes, and is conducive to the preparation of various high-performance composite materials.

[0076] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods in the following examples are not specified, and are generally according to the conventional procedures, or according to the conditions recommended by the manufacturer. Unless otherwise specified, percentages and parts are calculated by weight.

[0077] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as familiar to one skilled in the art. In addition, any method and material similar or equivalent to those described can be used in the method of the present application. The preferred implementation methods and materials described herein are only for demonstration.

[0078] Example 1

[0079]

[0080] (1) 0.864g tetraphenylacetylene silane, 0.984g 3,3'-(1,4-phenyl) disydney ketone, 15ml N-methyl pyrrolidone were added to a dry four-necked flask, and heated to 170 DEG C under nitrogen protection, and reacted for 4h under high-speed stirring. After the reaction was completed, it was cooled to room temperature.

[0081] (2) The product solution from step (1) was poured into 200 ml H2O, a large amount of dark brown precipitate appeared, suction filtration, the filter residue was washed with deionized water and ethanol solution several times, and dried to obtain a yellow solid, which was a low-temperature modified silicon acetylene resin prepolymer.

[0082] (3) After grinding the prepolymer of step (2), a small amount of THF was dissolved and coated on an aluminum plate, and heated in an oven at 50°C for 30 min until the solvent completely volatilized.

[0083] (4) The sample prepared in step (3) was cured in a muffle furnace according to the conditions of 200°C / 2h+220°C / 2h+250°C / 2h+280°C / 5h, and the muffle furnace was cooled to room temperature to obtain the cured product of the low-temperature cured modified silicon acetylene resin.

[0084] The cured product was tested by TGA at a heating rate of 10°C / min in a nitrogen atmosphere and an air atmosphere.

[0085] The same formula and reaction temperature, the pre-polymerization time was changed, and a plurality of cured product samples were prepared, and the thermal decomposition temperature (T d5 ) and the mass retention rate at 1000°C obtained by TGA test were as follows:

[0086]

[0087] Example 2

[0088] (1) 0.864g tetraphenylacetylene silane, 1.13g 3,3'-(1,4-phenyl) disilyl ketone, 15ml N-methyl pyrrolidone were added to a dry four-necked flask, heated to 180°C under nitrogen protection, and reacted for 2h under high speed stirring. After the reaction was completed, it was cooled to room temperature.

[0089] (2) The product solution obtained in step (1) was poured into 200ml ethanol, a large amount of black precipitate appeared, suction filtration, the filter residue was washed with deionized water and methanol several times, and dried to obtain a dark yellow solid, which was a low-temperature modified silicon acetylene resin prepolymer.

[0090] (3) After grinding the prepolymer of step (2), a certain amount of THF was dissolved and coated on an aluminum plate, and heated in an oven at 50°C for 30 min until the solvent completely volatilized, and the coating step was repeated three times.

[0091] (4) The sample prepared in step (3) was cured in a muffle furnace according to the conditions of 200°C / 2h+220°C / 2h+250°C / 2h+300°C / 5h, and the muffle furnace was cooled to room temperature to obtain the cured product of the low-temperature cured modified silicon acetylene resin.

[0092] The cured product was subjected to TGA test at a temperature rising rate of 10°C / min in nitrogen atmosphere and air atmosphere.

[0093] The same formulation and reaction temperature were used, and the prepolymerization time was changed to prepare a plurality of cured product samples, respectively. The thermal decomposition temperature (T d5 ) at which 5% mass loss was obtained and the mass retention rate at 1000°C obtained by TGA test were as shown in the following table, respectively:

[0094]

[0095] Example 3

[0096] (1) 0.864 g of tetraphenylacetylene silane, 0.738 g of 3,3'-(1,4-phenyl) disilyl ketone, and 15 ml of N-methyl pyrrolidone were added to a dry four-necked flask, and the reaction was carried out at 160°C for 8 h under nitrogen protection with high-speed stirring. After the reaction was completed, it was cooled to room temperature.

[0097] (2) The product solution obtained in step (1) was poured into 200 ml of methanol, and a large amount of black precipitate appeared. The filter residue was washed with deionized water and methanol several times, and dried to obtain a brown solid, which was a low-temperature modified silicon-acyl resin prepolymer.

[0098] (3) The prepolymer of step (2) was ground, and a small amount of DMF was dissolved and coated on an aluminum plate, which was heated in an oven at 150°C for 30 min until the solvent was completely volatilized.

[0099] (4) The sample prepared in step (3) was cured in a muffle furnace according to the conditions of 200°C / 2h + 220°C / 2h + 250°C / 2h + 280°C / 5h in a stepwise temperature rising manner. When the muffle furnace was cooled to room temperature, a cured product of the low-temperature cured modified silicon-acyl resin was obtained.

[0100] The cured product was subjected to TGA test at a temperature rising rate of 10°C / min in nitrogen atmosphere and air atmosphere.

[0101] The same formulation and reaction temperature were used, and the prepolymerization time was changed to prepare a plurality of cured product samples, respectively. The thermal decomposition temperature (T d5 ) at which 5% mass loss was obtained and the mass retention rate at 1000°C obtained by TGA test were as shown in the following table, respectively:

[0102]

[0103] All the documents mentioned in the present application are incorporated herein by reference as if each document were individually incorporated by reference. In addition, it is to be understood that various alterations and modifications can be made to the application upon reading and understanding the above lecture of the present application, and it is intended that all such alterations and modifications fall within the scope of the appended claims.

Claims

1. A modified tetraphenylethynylsilane resin prepolymer, characterized in that: The prepolymer is made of tetraphenylethynylsilane and sydney ketone; the prepolymer has a three-dimensional network structure and has the following repeating structural units: Wherein, R represents a phenylene group, On silicon atoms The connection structure indicating this site is omitted, and this site is a structure produced by the reaction of phenylethynyl or the alkynyl in phenylethynyl with the five-membered heterocyclic moiety in Sydney ketone.

2. The prepolymer according to claim 1, wherein The number average molecular weight Mn of the prepolymer is 4000-6000; and / or the weight average molecular weight Mw is 7000-9000.

3. A method for preparing the modified tetraphenylethynylsilane resin prepolymer according to claim 1, characterized in that: The steps include: Sydney ketone reacts with tetraphenylethynylsilane in an organic polar solvent to obtain the modified tetraphenylethynylsilane resin prepolymer.

4. The method according to claim 3, wherein The reaction temperature is 120-180°C.

5. The method according to claim 3, wherein The reaction temperature is 140-180°C.

6. The method according to claim 3, wherein The reaction temperature is 160-180°C.

7. The method according to claim 3, wherein The reaction time is 2 to 12 hours.

8. The method according to claim 3, wherein The reaction time is 4-8h.

9. The method according to claim 3, wherein The Sydney ketone has a structure selected from the group consisting of:

10. The method according to claim 3, wherein The molar ratio of the tetraphenylethynylsilane to the sydney ketone is 1:(1.5-2.5).

11. The method according to claim 3, wherein The molar ratio of the tetraphenylethynylsilane to the sydney ketone is 1:

2.

12. The method according to claim 3, wherein The organic polar solvent is selected from the group consisting of N,N-dimethylformamide, N-methylpyrrolidone, N,N-dimethylacetamide, or a combination thereof.

13. The method according to claim 3, wherein The organic polar solvent is selected from N-methylpyrrolidone.

14. The method according to claim 3, wherein The method includes: Under the protection of inert gas, tetraphenylethynylsilane and sydney ketone are dissolved in an organic polar solvent in a molar ratio of 1:(1.5-2.5), and reacted at 120-180° C. for 2-12 hours to obtain the modified tetraphenylethynylsilane resin prepolymer.

15. A cured product of the modified tetraphenylethynylsilane resin prepolymer according to claim 1, characterized in that: The cured product is obtained by curing the modified tetraphenylethynylsilane resin prepolymer according to claim 1.

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