CN116200035A - PAI composite material for valve body sealing and preparation method thereof - Google Patents

Abstract

The invention discloses a PAI composite material used for valve body sealing and a preparation method thereof, which comprises the following components in parts by weight: 50-65 parts of SiO ₂ /PAI composite material; 20-26 parts of epoxy resin; 4 ～8 parts of carbon fiber; 3～12 parts of acetone; 10～16 parts of dibutyl phthalate; 2～8 parts of graphene; 1～4 parts of vulcanizing agent; 3～12 parts of accelerator; 10～22 parts of anti-aging agent; the doping amount of SiO ₂ in the SiO ₂ /PAI composite material is 10-15%. Add SiO ₂ /PAI composite material to the components. Nano-SiO ₂ has the advantages of small particle size, high bond energy and good heat resistance. By compounding SiO ₂ and PAI, the thermal stability of the valve body seal is improved. After nano-doping PAI, the corona resistance life of the valve body seal is significantly improved.

Description

A kind of PAI composite material used for valve body sealing and preparation method thereof

technical field

The invention relates to a PAI composite material used for valve body sealing and a preparation method thereof.

Background technique

Polyamide-imide PAI is a kind of high-performance polymer whose main chain is bonded by imide ring and amide group. Due to the heat-resistant aromatic heterocyclic imide group and flexible amide group in the molecule Therefore, it not only has excellent heat resistance, dielectric properties, mechanical properties, creep resistance, corrosion resistance and chemical stability of polyimide, but also has excellent mechanical properties and processability of polyamide. It is an engineering material with excellent performance, which is widely used in aerospace, electronic devices and other fields.

Because polyamide-imide has high temperature resistance, friction resistance and radiation resistance, as well as good mechanical strength and adhesion, it is an ideal high temperature resistant thermoplastic engineering plastic. Among the amorphous thermoplastic engineering plastics sold commercially, PAI has the highest glass transition temperature, and its thermal stability is similar to that of polyimide, but PAI has more superior processing performance and mechanical properties, and is compatible with most engineering polymers. Than, PAI showed a higher intensity. At present, PAI is widely used in valve body seals, but the performance of various aspects of valve body seals still needs to be improved.

Contents of the invention

In order to improve the performance of valve body seals, the invention provides a PAI composite material for valve body seals and a preparation method thereof, the specific scheme is as follows:

A PAI composite material used for valve body sealing, comprising the following components in parts by weight:

50-65 parts of SiO ₂ /PAI composite material;

20-26 parts of epoxy resin;

4 to 8 parts of carbon fiber;

3-12 parts of acetone;

10-16 parts of dibutyl phthalate;

2 to 8 parts of graphene;

1 to 4 parts of vulcanizing agent;

3-12 accelerators;

10-22 parts of anti-aging agent;

The doping amount of SiO ₂ in the SiO ₂ /PAI composite material is 10-15%.

Further, the preparation method of the SiO ₂ /PAI composite material includes the following steps:

S1: Add ethyl orthosilicate, methyltriethoxysilane, and toluene into the container and stir;

S2: Add deionized water dropwise to the S1 solution under the action of ultrasound, perform ultrasonic stirring, and react after the stirring is completed;

S3: After reacting for a period of time, add N,N'-dimethylacetamide dropwise to a certain concentration to obtain a nano-SiO ₂ dispersion;

S4: Mechanically blending the nano- _SiO2 dispersion prepared in S3 with polyamide-imide, and mechanically stirring to obtain a uniform and stable nano-modified polyamide-imide resin solution.

Further, N,N'-dimethylacetamide is added dropwise to S3 to a certain concentration of 10-20%.

A preparation method for a PAI composite material for valve body sealing, comprising the following steps:

S1: Prepare materials according to the weight parts of the raw materials, and dry the raw materials;

S2: Thoroughly stir and mix the dried raw materials;

S3: Put the raw materials into the mold for compaction;

S4: Put it into a sintering furnace to sinter with a certain heating curve.

Further, the molding pressure in S3 is 20-30 MPa.

Further, the temperature rise curve in S4 is starting at room temperature, raising the temperature to 200°C at a rate of 1.5-2°C/min, keeping the temperature for 30 minutes, and then raising the temperature to 400-450°C at a rate of 1.5-2°C/min, and holding After 30min, cool to room temperature after the heat preservation.

Beneficial effect:

(1) The present invention provides a PAI composite material for valve body sealing and its preparation method, adding SiO ₂ /PAI composite material to the components, nano-SiO ₂ has small particle size, high bond energy and heat resistance Good and other advantages, by compounding SiO ₂ and PAI to improve the thermal stability of the valve body seal, after nano doping of PAI, the corona resistance life of the valve body seal is significantly improved.

(2) The present invention optimizes the doping amount of nano-SiO ₂ to 10-15%. When the doping amount of nano-SiO ₂ is lower than 10% or higher than 15%, the performance of the valve body seal will decrease.

(3) The present invention provides a method for preparing a PAI composite material used for valve body sealing, which optimizes the heating curve during firing and further enhances the mechanical properties of the valve body seal.

Detailed ways

In order to deepen the understanding of the present invention, the present invention will be further described below in conjunction with examples, which are only used to explain the present invention and do not constitute a limitation to the protection scope of the present invention.

Example 1:

A preparation method for a PAI composite material for valve body sealing, comprising the following steps:

Step 1. Preparation of SiO ₂ /PAI composite material:

S1: Add ethyl orthosilicate, methyltriethoxysilane, and toluene into the container and stir;

S2: Add deionized water dropwise to the S1 solution under the action of ultrasound, perform ultrasonic stirring, and react after the stirring is completed;

S3: After reacting for a period of time, add N,N'-dimethylacetamide dropwise to a concentration of 12%, to obtain a nano- _SiO2 dispersion;

S4: Mechanically blending the nano- _SiO2 dispersion prepared in S3 with polyamide-imide, and mechanically stirring to obtain a uniform and stable nano-modified polyamide-imide resin solution.

Step 2. Prepare raw materials:

55 parts SiO ₂ /PAI composite material; 24 parts epoxy resin; 6 parts carbon fiber;

6 parts of acetone; 10 parts of dibutyl phthalate; 2 parts of graphene; 1 part of vulcanizing agent; ₃ parts of accelerator _; The amount is 10%; the above raw materials are dried;

Step 3, fully stirring and mixing the dried raw materials;

Step 4, put the raw materials into the mold for compaction molding, and the molding pressure is 20MPa;

Step 5. Put it into a sintering furnace for firing. The firing temperature is starting at room temperature, and the temperature is raised to 200°C at a rate of 1.5°C/min, kept for 30 minutes, and then raised to 400°C at a rate of 1.5°C/min. , keep warm for 30min, and cool to room temperature after the keep warm.

Example 2:

A preparation method for a PAI composite material for valve body sealing, comprising the following steps:

Step 1. Preparation of SiO ₂ /PAI composite material:

S1: Add ethyl orthosilicate, methyltriethoxysilane, and toluene into the container and stir;

S2: Add deionized water dropwise to the S1 solution under the action of ultrasound, perform ultrasonic stirring, and react after the stirring is completed;

S3: After reacting for a period of time, add N,N'-dimethylacetamide dropwise to a concentration of 15% to obtain a nano- _SiO2 dispersion;

S4: Mechanically blending the nano- _SiO2 dispersion prepared in S3 with polyamide-imide, and mechanically stirring to obtain a uniform and stable nano-modified polyamide-imide resin solution.

Step 2. Prepare raw materials:

60 parts of SiO ₂ /PAI composite material; 23 parts of epoxy resin; 6 parts of carbon fiber;

6 parts of acetone; 12 parts of dibutyl _phthalate ; 5 parts of graphene; 2 parts of vulcanizing agent; ₇ parts of accelerator; The amount is 13%; the above raw materials are dried;

Step 3, fully stirring and mixing the dried raw materials;

Step 4, put the raw materials into the mold for compaction molding, and the molding pressure is 25MPa;

Step 5. Put it into a sintering furnace for firing. The firing temperature is starting at room temperature, and the temperature is raised to 200°C at a rate of 1.8°C/min, kept for 30 minutes, and then raised to 420°C at a rate of 1.7°C/min. , keep warm for 30min, and cool to room temperature after the keep warm.

Example 3:

A preparation method for a PAI composite material for valve body sealing, comprising the following steps:

Step 1. Preparation of SiO ₂ /PAI composite material:

S1: Add ethyl orthosilicate, methyltriethoxysilane, and toluene into the container and stir;

S2: Add deionized water dropwise to the S1 solution under the action of ultrasound, perform ultrasonic stirring, and react after the stirring is completed;

S3: After reacting for a period of time, add N, N'-dimethylacetamide dropwise to a concentration of 20%, to obtain a nano-SiO2 dispersion;

S4: Mechanically blending the nano- _SiO2 dispersion prepared in S3 with polyamide-imide, and mechanically stirring to obtain a uniform and stable nano-modified polyamide-imide resin solution.

Step 2. Prepare raw materials:

65 parts of SiO2/PAI composite material; 26 parts of epoxy resin; 8 parts of carbon fiber;

12 parts of acetone; 16 parts of dibutyl phthalate _; 8 parts of graphene; 4 parts of vulcanizing agent; ₁₂ parts of accelerator; The amount is 15%; the above raw materials are dried;

Step 3, fully stirring and mixing the dried raw materials;

Step 4, put the raw materials into the mold for compaction molding, the molding pressure is 30MPa;

Step 5. Put it into a sintering furnace for firing. The firing temperature is starting at room temperature, and the temperature is raised to 200°C at a rate of 2°C/min, kept for 30 minutes, and then raised to 450°C at a rate of 2°C/min. , keep warm for 30min, and cool to room temperature after the keep warm.

The performance testing of the valve body seals prepared in Examples 1-3 shows that the performance of the valve body seals is enhanced by doping nano-SiO ₂ .

As a further improvement, the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall include Within the protection scope of the present invention.

Claims (6)

1. The PAI composite material for sealing the valve body is characterized by comprising the following components in parts by weight:

50-65 parts of SiO ₂ PAI composite material;

20-26 parts of epoxy resin;

4-8 parts of carbon fiber;

3-12 parts of acetone;

10-16 parts of dibutyl phthalate;

2-8 parts of graphene;

1-4 parts of vulcanizing agent;

3-12 parts of accelerator;

10-22 parts of an anti-aging agent;

the SiO is ₂ SiO in PAI composite material ₂ The doping amount of (2) is 10-15%.

2. A PAI composite for valve body sealing as in claim 1 wherein the SiO ₂ The preparation method of the PAI composite material comprises the following steps:

s1: adding ethyl orthosilicate, methyltriethoxysilane and toluene into a container and stirring;

s2: dropwise adding deionized water into the solution S1 under the action of ultrasound, performing ultrasonic stirring, and performing reaction after stirring is completed;

s3: after reacting for a period of time, dropwise adding N, N' -dimethylacetamide to a certain concentration to obtain nano SiO ₂ A dispersion;

s4: nano SiO prepared by S3 ₂ And mechanically blending the dispersion liquid and the polyamide-imide, and mechanically stirring to obtain uniform and stable nano modified polyamide-imide resin liquid.

3. The PAI composite for valve body sealing according to claim 2, wherein N, N' -dimethylacetamide is added dropwise to a concentration of 10 to 20% in S3.

4. A method of preparing a PAI composite for sealing a valve body as claimed in claims 1 to 3, comprising the steps of:

s1: preparing materials according to the weight parts of the raw materials, and drying the raw materials;

s2: fully stirring and mixing the dried raw materials;

s3: filling the raw materials into a die, and compacting and molding;

s4: and (5) placing the mixture into a sintering furnace to be sintered according to a certain heating curve.

5. The method for producing a PAI composite for valve body sealing according to claim 4, wherein the molding pressure in S3 is 20 to 30MPa.

6. The method for preparing a PAI composite material for sealing a valve body according to claim 4, wherein the temperature rising curve in S4 is to raise the temperature to 200 ℃ at a rate of 1.5-2 ℃/min, heat-preserving for 30min, then raise the temperature to 400-450 ℃ at a rate of 1.5-2 ℃/min, heat-preserving for 30min, and cooling to the room temperature after heat preservation is finished.