CN114717681A - A kind of high temperature resistant, flame retardant polyamideimide based filament and its green preparation and in-situ reinforcement method - Google Patents

Abstract

The invention belongs to the technical field of fiber materials, and discloses a high-temperature-resistant and flame-retardant polyamideimide-based filament and a green preparation and in-situ reinforcement method thereof. The PAI content in the filament is more than or equal to 90%, the diameter of the filament is 0.1-2 mm, and the limiting oxygen index of the filament is 40-50%; the filament is prepared in a green color in coagulation bath water by a wet spinning technology, another component of polymer is introduced as an elastomer in the spinning process, and the elastomer is heated in situ to be molten, so that the in-situ enhancement of the mechanical tensile property of the filament is realized based on the principle of 'rigid/flexible polymer network complementation'. The filament has the advantages of high temperature resistance, flame retardance, excellent mechanical properties, simple and convenient preparation method, easy operation and low cost, and has wide application prospect in the fields of high-temperature filtration, battery diaphragm, flame retardant protection and the like.

Description

A kind of high temperature-resistant, flame-retardant polyamideimide-based filament and its green preparation and in-situ reinforcement method

technical field

The invention belongs to the field of new materials, and relates to a high-temperature-resistant and flame-retardant polyamideimide (PAI)-based filament, in particular to a green preparation and in-situ reinforcement method of the filament, specifically using water as a coagulation bath , PAI filaments are prepared by wet spinning technology, and another component polymer is introduced based on the principle of "rigid/flexible polymer network complementarity", and the in-situ reinforcement of the fiber is realized by in-situ heating, which expands its use in high-temperature filtration. , battery separator, flame retardant protection and other fields of application prospects.

Background technique

Polyimide (PI) is a special engineering material, and downstream products such as fibers, filaments, and fabrics prepared from it have excellent heat resistance (-269°C to 400°C), flame retardancy and self-extinguishing. It is widely used in many fields, such as transformer capacitor insulation materials, aerospace insulation materials, antistatic shielding materials used in high temperature environments, etc. However, PI has the inherent defects of being insoluble and difficult to melt, which makes its post-processing difficult, so the cost of various products is high, which limits its wide application in the civilian field.

As a homopolymer of PI, PAI has a glass transition temperature (250 to 300° C.) equivalent to it, and more importantly, it has good solubility, so it can be post-processed by solution spinning. The invention utilizes the wet spinning technology to realize the green preparation of the PA1 filament, and provides a novel textile raw material. Technologies closely related to the present invention are mainly obtained by searching for keywords "polyamideimide & filament", "polyamideimide & wet process", "polyamideimide & fiber". Among the disclosed technologies, French Rhone-Blanc Fiber Company disclosed polyamideimide filament and its wet preparation technology in "CN 1041406A Polyamideimide Filament Filament and its Production and Processing Method" in 1990. , but the patent focuses on the evaluation of the mechanical properties of the filament, and does not involve its flame retardant properties, and the method involved in the patent uses binary or ternary coagulation bath spinning, which does not meet the development needs of green production, and the technology in The obtained filament needs to be washed with water, and the present invention uses water as the coagulation bath, which is green and environmentally friendly, does not require water washing, and has low cost. The preparation of PAI fiber in the patent "CN103757721A One-step Wet Spinning Process of Polyamideimide Fiber" needs to go through two coagulation baths, and the coagulation bath contains toxic and harmful chemical reagents. The above technology is substantially different from the materials and preparation methods of this patent.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a new type of high-temperature resistant and flame-retardant filament, which can supplement high-performance materials in the fields of high-temperature filtration, battery diaphragm, and flame-retardant protection, and disclose its green preparation and mechanical properties in situ based on wet spinning technology. Enhancement method.

The present invention provides a high temperature-resistant and flame-retardant polyamideimide-based filament, which is composed of PAI and another polymer with a low melting point (≤240° C.).

As the preferred technical solution:

The above-mentioned high-temperature resistant and flame-retardant PAI-based filament, the main component of the material is PAI, the weight ratio is ≥90%, the polymer form is powder, liquid, and its molecular weight is 5,000-800,000. It is block or homopolymeric.

The above-mentioned high-temperature-resistant and flame-retardant PAI-based filament has a smooth surface, a cylindrical cross-section, and a diameter of 0.1-2 mm.

A kind of high temperature-resistant, flame-retardant PAI-based filament as described above, the PAI can be used as a rigid polymer network because it has a benzene ring, and the remaining components introduced are used as a flexible polymer network, and its melting temperature is lower than the glass of PAI The temperature (250°C) can be polyurethane, nylon, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polymethyl methacrylate, etc.

The above-mentioned high temperature-resistant and flame-retardant PAI-based filament, the material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, no melting droplets, and a limiting oxygen index of 40 to 50 %.

For the above-mentioned high-temperature-resistant and flame-retardant PAI-based filament, the mechanical tensile strength of the material is 20-200 MPa, and the elongation at break is 5-30%.

The invention also provides a green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments. The mixed solution of PAI and another component polymer is prepared, and the wet spinning technology is used, and water is used as a coagulation bath. , after synchronous spinning, a hybrid primary fiber is formed, and the mechanical properties of the fiber are improved by in-situ heating at the receiving roll.

As the preferred technical solution:

The above-mentioned green preparation method of high temperature resistant and flame retardant PAI-based filament, the other component polymer can be polyurethane, nylon, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral , polymethyl methacrylate, etc., the solvent can be one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and tetrahydrofuran.

In the above-mentioned green preparation method of high temperature-resistant and flame-retardant PAI-based filaments, the coagulation bath is water, which can be deionized water, distilled water, mineral water, tap water, and the like.

In the above-mentioned in-situ strengthening method of high temperature-resistant and flame-retardant PAI-based filaments, the concentration of the spinning solution is 20-40 wt%, and the spinning speed is 5-20 m/min.

The above-mentioned in-situ strengthening method for high temperature-resistant and flame-retardant PAI-based filaments utilizes in-situ heating by temperature-controlled receiving rollers, the heating temperature is adjustable in the range of 150-240° C., and the heating time is 1-10 hours. The mechanical properties of the filament before and after heating can be enhanced by 1 to 3 times.

beneficial effect

The high-temperature-resistant and flame-retardant polyamide-imide-based filament of the invention has advantages in raw materials and technology, and the raw materials are low in cost and easy to dissolve, so as to be easy for polymer processing and molding, flame retardant and high temperature resistance; the processing technology is green Coagulation bath wet spinning meets the development needs of ecological and environmental protection, and the existing technology has mature industrial equipment, so the material provided by the present invention is of great significance for the development of green industrial textiles.

The in-situ reinforcement method for high temperature-resistant and flame-retardant polyamideimide-based filaments provided by the invention has the advantages of simple operation and strong expandability, and can provide technical reference for the mechanical reinforcement of filaments or fiber materials

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

In this embodiment, a high temperature-resistant and flame-retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 91%, the polymer form is powder, its molecular weight is 10,000, and the type is homopolymerization; The surface of the silk is smooth, the cross-section is cylindrical, and the diameter is 0.2 mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polyurethane is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition temperature of PAI (250 ℃). ). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 43%; the mechanical tensile strength is 50MPa, and the elongation at break is 10 %.

Example 2

In this embodiment, a high temperature-resistant and flame-retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 93%, the polymer form is liquid, its molecular weight is 50,000, and the type is block type; The surface of the silk is smooth, the cross section is cylindrical, and the diameter is 0.4mm; the PAI can be used as a rigid polymer network because of its benzene ring, and nylon is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition temperature of PAI (250 ℃). ). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 44%; the mechanical tensile strength is 100MPa, and the elongation at break is 12 %.

Example 3

In this embodiment, a high temperature resistant and flame retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 92%, the polymer form is powder, its molecular weight is 60000, and the type is block type; The silk surface is smooth, the cross section is cylindrical, and the diameter is 0.4mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polyvinyl alcohol is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition temperature of PAI ( 250°C). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 45%; the mechanical tensile strength is 80MPa, and the elongation at break is 8 %.

Example 4

In this embodiment, a high temperature-resistant and flame-retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 94%, the polymer form is liquid, its molecular weight is 70,000, and the type is homopolymeric; The surface of the silk is smooth, the cross section is cylindrical, and the diameter is 0.8mm; the PAI can be used as a rigid polymer network due to its benzene ring, and polyvinyl formal is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition of PAI temperature (250°C). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 45%; the mechanical tensile strength is 150MPa, and the elongation at break is 13 %.

Example 5

In this embodiment, a high temperature resistant and flame retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 95%, the polymer form is powder, its molecular weight is 80000, and the type is homopolymeric; The surface of the silk is smooth, the cross section is cylindrical, and the diameter is 0.4mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polyvinyl butyral is introduced as a flexible polymer network, and its melting temperature is lower than that of the glass of PAI temperature (250°C). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 43%; the mechanical tensile strength is 130MPa, and the elongation at break is 18. %.

Example 6

In this embodiment, a high temperature-resistant and flame-retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 94%, the polymer form is liquid, its molecular weight is 90,000, and the type is block type; The surface of the silk is smooth, the cross-section is cylindrical, and the diameter is 0.8mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polymethyl methacrylate is introduced as a flexible polymer network, and its melting temperature is lower than the glass of PAI temperature (250°C). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 46%; the mechanical tensile strength is 105MPa, and the elongation at break is 21 %.

Example 7

In this embodiment, a high temperature-resistant and flame-retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 96%, the polymer form is powder, its molecular weight is 500,000, and the type is homopolymeric; The surface of the silk is smooth, the cross-section is cylindrical, and the diameter is 1mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polyvinyl butyral is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition of PAI. temperature (250°C). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 44%; the mechanical tensile strength is 87MPa, and the elongation at break is 15. %.

Example 8

In this embodiment, a high temperature resistant and flame retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 94%, the polymer form is liquid, its molecular weight is 600000, and the type is block type; The surface of the silk is smooth, the cross-section is cylindrical, and the diameter is 1.2 mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polyurethane is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition temperature of PAI (250 ℃). ). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 45%; the mechanical tensile strength is 113MPa, and the elongation at break is 18 %.

Example 9

In this embodiment, a high temperature-resistant and flame-retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 93%, the polymer form is powder, its molecular weight is 700,000, and the type is homopolymerization; The silk surface is smooth, the cross section is cylindrical, and the diameter is 1.4 mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polyvinyl alcohol is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition temperature of PAI ( 250°C). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 43%; the mechanical tensile strength is 84MPa, and the elongation at break is 15. %.

Example 10

In this embodiment, a high temperature-resistant and flame-retardant PAI-based filament, the main component of the fiber is PAI, the weight ratio is 95%, the polymer form is liquid, its molecular weight is 800,000, and the type is homopolymeric; The silk surface is smooth, the cross section is cylindrical, and the diameter is 1.8 mm; the PAI can be used as a rigid polymer network because of its benzene ring, and polyvinyl alcohol is introduced as a flexible polymer network, and its melting temperature is lower than the glass transition temperature of PAI ( 250°C). In addition, the fiber material can be used for a long time at 220 ° C, and has the characteristics of self-extinguishing, no smoke, and no melting droplets, the limiting oxygen index is 46%; the mechanical tensile strength is 111MPa, and the elongation at break is 19. %.

Example 11

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is nylon, and the solvent is N,N-dimethylformamide, The concentration of the spinning solution was 20 wt%, the coagulation bath was deionized water; the spinning speed was 5 m/min, and the temperature-controlled receiving roller was used for in-situ heating, the heating temperature was 200 °C, and the heating time was 2 h. Mechanical properties can be enhanced 1.2 times.

Example 12

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyvinyl alcohol, the solvent is N-methylpyrrolidone, and the spinning The concentration of the solution is 30 wt%, the coagulation bath is mineral water; the spinning speed is 8 m/min, and the temperature-controlled receiving roller is used for in-situ heating, the heating temperature is 180 °C, and the heating time is 3 h. 2x enhanced.

Example 13

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyvinyl butyral, the solvent is tetrahydrofuran, and the spinning solution is The concentration of the filament is 31wt%, the coagulation bath is distilled water; the spinning speed is 7m/min, the temperature-controlled receiving roller is used for in-situ heating, the heating temperature is 190 ℃, and the heating time is 2h. The mechanical properties of the filament before and after heating can be enhanced by 1.5 times.

Example 14

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyurethane, and the solvent is N,N-dimethylformamide, The concentration of the spinning solution was 25 wt%, the coagulation bath was deionized water; the spinning speed was 12 m/min, and the temperature-controlled receiving roller was used for in-situ heating, the heating temperature was 210 °C, and the heating time was 3 h. Mechanical properties can be enhanced 2 times.

Example 15

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyvinyl alcohol, and the solvent is N,N-dimethyl ethyl alcohol amide, the concentration of the spinning solution is 32wt%, the coagulation bath is distilled water; the spinning speed is 14m/min, and the temperature-controlled receiving roller is used for in-situ heating, the heating temperature is 180 ℃, and the heating time is 2h. Mechanical properties can be enhanced 1.8 times.

Example 16

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyurethane, and the solvent is N,N-dimethylformamide, The concentration of the spinning solution is 34 wt%, the coagulation bath is deionized water; the spinning speed is 17 m/min, and the temperature-controlled receiving roller is used for in-situ heating, the heating temperature is 190 ° C, and the heating time is 5 h. Mechanical properties can be enhanced 2.8 times.

Example 17

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polymethyl methacrylate, the solvent is tetrahydrofuran, and the spinning solution is The concentration of the filament is 34wt%, the coagulation bath is tap water; the spinning speed is 15m/min, the temperature-controlled receiving roller is used for in-situ heating, the heating temperature is 180 °C, and the heating time is 4h. The mechanical properties of the filament before and after heating can be enhanced by 1.5 times.

Example 18

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyvinyl formal, and the solvent is N-methylpyrrolidone, The concentration of the spinning solution was 23 wt%, the coagulation bath was tap water; the spinning speed was 9 m/min, and the temperature-controlled receiving roller was used for in-situ heating, the heating temperature was 220 °C, and the heating time was 3 h. The mechanical properties of the filament before and after heating Can be enhanced 3 times.

Example 19

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyvinyl formal, and the solvent is N-methylpyrrolidone, The concentration of the spinning solution was 25 wt%, the coagulation bath was mineral water; the spinning speed was 13 m/min, and the temperature-controlled receiving roller was used for in-situ heating, the heating temperature was 210 °C, and the heating time was 2 h. The mechanics of the filament before and after heating The performance can be enhanced by 2 times.

Example 20

In this embodiment, a one-step green preparation and in-situ reinforcement method of high temperature-resistant and flame-retardant PAI-based filaments, the other component polymer is polyurethane, and the solvent is N,N-dimethylformamide, The concentration of the spinning solution was 28 wt%, and the coagulation bath was mineral water; the spinning speed was 13 m/min, and the temperature-controlled receiving roller was used for in-situ heating, the heating temperature was 170 °C, and the heating time was 5 h. The mechanics of the filament before and after heating The performance can be enhanced by 2 times.

Claims (10)

1. The high-temperature-resistant and flame-retardant PAI-based filament is characterized in that the main component of the material is PAI, the weight proportion of the PAI is more than or equal to 90%, the polymer is in a powdery or liquid state, the molecular weight of the polymer is 5000-800000, and the polymer is in a block type or a homopolymerization type.

2. The high-temperature-resistant and flame-retardant PAI-based filament is characterized in that the surface of the filament is smooth, the cross section of the filament is cylindrical, and the diameter of the filament is 0.1-2 mm.

3. A high temperature resistant, flame retardant PAI-based filament as claimed in claim 1 wherein the PAI is a rigid polymer network due to its benzene ring and the remaining components are incorporated as a flexible polymer network having a melting temperature below the glass transition temperature (250 ℃) of PAI, which can be polyurethane, nylon, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polymethyl methacrylate, etc.

4. A high temperature resistant, flame retardant PAI based filament as in claim 1 wherein the material is capable of long term use below 220 ℃ and has self-extinguishing, non-fuming, non-dripping characteristics from fire, limiting oxygen index of 30-50%.

5. A high temperature resistant, flame retardant PAI based filament as claimed in claim 1 wherein the material has a mechanical tensile strength of 20 to 200MPa and an elongation at break of 5 to 30%.

6. A green manufacturing method of PAI-based filament with high temperature resistance and flame retardance as claimed in claim 1, wherein the PAI, the other component polymer and the solvent are mixed to prepare a mixed solution, and then the mixed solution is extruded into the coagulation bath by using water as the coagulation bath by using the wet spinning technology to obtain the hybrid nascent fiber.

7. A process for preparing high temperature resistant, flame retardant PAI based filaments in green form as claimed in claim 6, wherein the other component polymer is selected from polyurethane, nylon, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polymethyl methacrylate, etc., and the solvent is selected from one or more of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran.

8. A process for the green production of high temperature resistant, flame retardant PAI based filaments as claimed in claim 6 wherein the coagulation bath is water, such as deionized water, distilled water, mineral water, tap water, etc.

9. The in-situ reinforcement method for PAI-based filament with high temperature resistance and flame retardance as claimed in claim 1, wherein the concentration of the spinning solution is 20-40 wt% and the spinning speed is 5-20 m/min.

10. The in-situ reinforcement method of the PAI-based filament yarn with high temperature resistance and flame retardance as claimed in claim 1, wherein a temperature-controllable receiving roller is used for in-situ heating, the heating temperature is adjustable within the range of 150-240 ℃, the heating time is 1-10 hours, and the mechanical property of the filament yarn before and after heating can be enhanced by 1-3 times.