Antistatic graphene-polyamide composite fiber and preparation method thereof

Abstract

The application provides an antistatic graphene-polyamide composite fiber and a preparation method thereof. The antistatic graphene-polyamide composite fiber is prepared by melt spinning and drawing of a mixture of modified polyamide and a tin antimony oxide-graphene oxide nanocomposite material. The modified polyamide is prepared by reaction of pre-modified polyamide and 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole. The pre-modified polyamide is prepared by reaction of caprolactam, bis(4-carboxyphenyl)phenyl phosphine oxide-diethylenetriamine salt and adipic acid, and then by reaction with polyether amine. The tin antimony oxide-graphene oxide nanocomposite material is prepared by reaction of tin antimony oxide, 3-aminopropyl triethoxysilane and graphene oxide. The antistatic graphene-polyamide composite fiber prepared by the application has good antistatic, halogen-free flame-retardant and ultraviolet-resistant anti-aging properties, and is suitable for antistatic workwear and outdoor industrial fabrics.

Description

Technical Field

[0001] This invention relates to the field of textile fiber technology, specifically to an antistatic graphene-nylon composite fiber and its preparation method. Background Technology

[0002] Nylon fiber is widely used in socks, outdoor clothing fabrics, and tire cord fabrics, among many other fields. However, nylon fiber and its products have poor light resistance during use; prolonged exposure to ultraviolet light can cause yellowing and structural damage. Furthermore, due to the inherent insulating nature of nylon fiber, the charge generated during friction cannot be transferred promptly. The accumulated charge on the surface can break down the air insulation, generating sparks that can ignite the fiber itself or surrounding combustibles, creating a fire source. Additionally, because nylon fiber consists of relatively weak covalent bonds, when exposed to flame and gain energy, these covalent bonds break, generating free radicals and triggering a chain reaction that continues the combustion of the polymer, leading to a fire. Therefore, improving the flame-retardant, antistatic, and anti-aging properties of nylon fiber is crucial. Summary of the Invention

[0003] The purpose of this invention is to provide an antistatic graphene-nylon composite fiber and its preparation method, specifically an antistatic graphene-nylon composite fiber with good antistatic, flame retardant and anti-aging properties and its preparation method.

[0004] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing antistatic graphene-nylon composite fibers, the preparation method comprising the following steps: (1) Diethylenetriamine and anhydrous ethanol were mixed evenly, and bis(4-carboxyphenyl)phenylphosphine oxide was added. The mixture was heated and stirred to react, filtered under reduced pressure, and washed to obtain bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt. Under a nitrogen atmosphere, caprolactam, bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, adipic acid and deionized water were mixed and heated and pressurized to react. After the reaction was completed, the pressure was reduced to normal pressure, polyetheramine and sodium hypophosphite were added, and the mixture was heated and pressurized again. After the reaction was completed, the pressure was reduced and maintained for a certain time. After condensation in cooling water, the mixture was granulated to obtain pre-modified polyamide. (2) The pre-modified polyamide, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and N,N-dimethylacetamide were mixed in an ice-water bath, heated and stirred to react. After the reaction was completed, the mixture was distilled under reduced pressure, washed and dried to obtain the modified polyamide. (3) Under a nitrogen atmosphere, antimony tin oxide and deionized water were mixed and ultrasonically dispersed. 50wt% aqueous ethanol solution and 3-aminopropyltriethoxysilane were added, and the mixture was heated and stirred. After the reaction was completed, the mixture was centrifuged, washed, filtered, and dried to obtain modified antimony tin oxide. (4) Mix the modified tin antimony oxide and 10 g / L graphene oxide aqueous solution evenly, add sodium hydroxide aqueous solution to adjust the pH, centrifuge with deionized water, centrifuge and wash the upper suspension until neutral, collect the lower colloid, dry, and obtain tin antimony oxide-graphene oxide nanocomposite material. (5) Modified polyamide and antimony tin oxide-graphene oxide nanocomposite materials were mixed, melt-spun and drawn to obtain antistatic graphene-nylon composite fiber.

[0005] Further, the mass ratio of diethylenetriamine, anhydrous ethanol, and bis(4-carboxyphenyl)phenylphosphine oxide in step (1) is (5~7):(180~220):(20~25).

[0006] Furthermore, the heating and stirring reaction in step (1) is carried out at a temperature of 55-65°C for 1-2 hours.

[0007] Further, the mass ratio of caprolactam, bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, adipic acid, deionized water, polyetheramine, and sodium hypophosphite in step (1) is (30~35):(0.6~0.8):(2~2.5):(0.9~1.0):(35~40):(0.6~0.8).

[0008] Further, the heating and pressurizing reaction in step (1) is carried out at a temperature of 230~240℃, a pressure of 0.5~0.6MPa, and a reaction time of 4~5h.

[0009] Further, the temperature of the reheating and pressurization reaction in step (1) is 240~250℃, the pressure is 0.2~0.3MPa, and the reaction time is 1~1.5h.

[0010] Further, the pressure reduction and maintenance time in step (1) is to reduce the pressure to 400~500Pa within 1 hour and maintain it for 20~40 minutes.

[0011] Further, in step (2), the mass ratio of the pre-modified polyamide, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and N,N-dimethylacetamide is (100~200):(4.5~5.5):(500~1000).

[0012] Furthermore, the heating and stirring reaction in step (2) is carried out at 25~35℃ for 20~24h.

[0013] Further, in step (3), the mass ratio of antimony tin oxide, deionized water, 50wt% aqueous ethanol solution, and 3-aminopropyltriethoxysilane is (3~3.5):(180~200):(180~200):(20~25).

[0014] Furthermore, the reaction temperature of the heating and stirring reaction in step (3) is 50~60℃, and the reaction time is 8~10h.

[0015] Further, in step (4), the mass ratio of modified antimony tin oxide to 10 g / L graphene oxide aqueous solution is (0.2~0.3):(80~120).

[0016] Further, step (4) involves adjusting the pH to 9-10.

[0017] Further, the mass ratio of the modified polyamide and the antimony tin oxide-graphene oxide nanocomposite material in step (5) is (10~15):(0.1~0.2).

[0018] Further, the process parameters for melt spinning in step (5) are as follows: the screw temperature in zone 1 is 255℃, the screw temperature in zone 2 is 270℃, the screw temperature in zone 3 is 265℃, the screw temperature in zone 4 is 265℃, the metering pump temperature is 265℃, the spinning box temperature is 265℃, the pump supply is 35g / min, the number of spinnerets is 36, the spinneret diameter is 0.4mm, the component pressure is 8~10MPa, and the spinning speed is 800m / min.

[0019] Further, the process parameters for stretching in step (5) are: hot roller temperature of 60°C, hot plate temperature of 120°C, and stretching ratio of 1.5~2.5.

[0020] Furthermore, the antimony tin oxide has a particle size of 7~10nm and was purchased from Shanghai Huben New Materials Technology Co., Ltd.

[0021] Furthermore, the graphene oxide is a single-layer graphene oxide with a lateral dimension of 0.5~10μm, and was purchased from Shanghai Myriel Biochemical Technology Co., Ltd.

[0022] Furthermore, the polyetheramine has a number-average molecular weight of 2000 g / mol and was purchased from Huntsman (China) Co., Ltd.

[0023] Secondly, the present invention provides an antistatic graphene-nylon composite fiber prepared by a method for preparing antistatic graphene-nylon composite fiber.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: In the preparation of antistatic graphene-nylon composite fiber, the present invention reacts bis(4-carboxyphenyl)phenylphosphine oxide with diethylenetriamine to obtain bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt; after reacting caprolactam with bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, adipic acid, and deionized water, it reacts with polyetheramine to obtain pre-modified polyamide; the pre-modified polyamide is reacted with 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole to obtain modified polyamide; antimony tin oxide, 3-aminopropyltriethoxysilane and graphene oxide are reacted to obtain antimony tin oxide-graphene oxide nanocomposite material; the modified polyamide and antimony tin oxide-graphene oxide nanocomposite material are mixed and melt-spun and drawn to obtain antistatic graphene-nylon composite fiber.

[0025] First, bis(4-carboxyphenyl)phenylphosphine oxide reacts with diethylenetriamine to prepare bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, which participates in the polymerization reaction as a reactive flame retardant. During combustion, phosphorus promotes char formation, captures free radicals, and synergistically retards with nitrogen on the polyamide molecule, improving the flame retardant properties of antistatic graphene-nylon composite fibers. Simultaneously, the generated bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt contains a secondary amine group, which can undergo a Michael addition reaction with the unsaturated double bond on 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, introducing a benzotriazole-type UV absorber onto the polyamide molecule, thereby improving anti-aging properties. Caprolactam reacts with bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt... After reacting with ethylenetriamine salt, adipic acid, and deionized water, a polyamide-polyether block copolymer is prepared by reacting with polyetheramine. The charge transfer effect of the ether oxygen atoms in the polyetheramine chain and the hydrophilicity of the polyether allow the charge accumulated in the fiber to be quickly released, thereby improving the antistatic properties of the antistatic graphene-nylon composite fiber. The benzotriazole group can absorb ultraviolet light and convert it into heat energy. The secondary amine on the pre-modified polyamide undergoes a Michael addition reaction with the unsaturated double bond on 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and the ultraviolet absorber with double bond is covalently grafted onto the polyamide molecular chain, inhibiting the polyamide molecular chain breakage, yellowing, and mechanical property degradation caused by ultraviolet light, and improving the anti-aging properties of the antistatic graphene-nylon composite fiber.

[0026] Secondly, tin antimony oxide, 3-aminopropyltriethoxysilane, and graphene oxide were reacted to prepare tin antimony oxide-graphene oxide nanocomposite materials. Graphene oxide is a novel nanomaterial with water dispersibility, high specific surface area, and chemical modification properties. Adding it to polyamide can improve the flame retardancy and mechanical properties of the material. However, graphene oxide itself does not have electrical conductivity, while tin antimony oxide is an N-type semiconductor doped with Sb in SnO2, which has high conductivity, wear resistance, and corrosion resistance. Using graphene oxide as a precursor, tin antimony oxide was anchored onto graphene oxide sheets using 3-aminopropyltriethoxysilane to prepare tin antimony oxide-graphene oxide nanocomposite materials with high specific surface area, water dispersibility, and conductivity. At the same time, tin antimony oxide has a good blocking effect on ultraviolet light, further improving the anti-aging properties of antistatic graphene-nylon composite fibers.

[0027] Finally, after mixing the modified polyamide with the tin antimony oxide-graphene oxide nanocomposite material, melt spinning and drawing were performed to obtain antistatic graphene-nylon composite fiber. The hydrophilic polyetheramine on the modified polyamide and the conductive tin antimony oxide on the tin antimony oxide-graphene oxide nanocomposite material synergistically improved the antistatic properties of the antistatic graphene-nylon composite fiber. At the same time, the carboxyl groups, hydroxyl groups and other groups on the tin antimony oxide-graphene oxide nanocomposite material can form hydrogen bonds with the modified polyamide, so that the tin antimony oxide-graphene oxide nanocomposite material can be uniformly dispersed on the modified polyamide. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1 A method for preparing antistatic graphene-nylon composite fiber includes the following preparation steps: (1) By mass fraction, 5 parts of diethylenetriamine and 180 parts of anhydrous ethanol were mixed evenly at 0°C, and 20 parts of bis(4-carboxyphenyl)phenylphosphine oxide were added. The mixture was stirred and reacted at 55°C for 1 h, filtered under reduced pressure, and washed three times with anhydrous ethanol to obtain bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt. Under a nitrogen atmosphere, by mass fraction, 30 parts of caprolactam, 0.6 parts of bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, 2 parts of adipic acid, and 0.9 parts of deionized water were mixed evenly and reacted at 230°C and 0.5 MPa for 4 h. The pressure was reduced to atmospheric pressure, and 35 parts of polyetheramine and 0. Six parts of sodium hypophosphite were reacted at 0.2 MPa and 240 °C for 1 h. The pressure was then reduced to 400 Pa and maintained for 20 min. After condensation in cooling water, the mixture was pelletized to obtain pre-modified polyamide. In an ice-water bath, 100 parts of pre-modified polyamide, 4.5 parts of 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and 500 parts of N,N-dimethylacetamide were mixed evenly, heated to 25 °C, and stirred for 20 h. The N,N-dimethylacetamide was removed by vacuum distillation, and the mixture was washed three times with anhydrous ethanol and dried under vacuum at 50 °C for 10 h to obtain modified polyamide. (2) Under a nitrogen atmosphere, 3 parts of antimony tin oxide powder and 180 parts of deionized water were mixed evenly and ultrasonically dispersed for 40 min. 180 parts of 50 wt% ethanol aqueous solution and 20 parts of 3-aminopropyltriethoxysilane were added and stirred at 50 °C for 8 h. The mixture was washed three times each with anhydrous ethanol and deionized water, filtered, and vacuum dried at 40 °C for 10 h to obtain modified antimony tin oxide. 0.2 parts of modified antimony tin oxide and 80 parts of 10 g / L graphene oxide aqueous solution were added to 10 wt% sodium hydroxide aqueous solution to adjust the pH to 9. The mixture was centrifuged at 2000 r / min for 10 min with deionized water. The resulting upper suspension was centrifuged at 5000 r / min and washed until the pH of the supernatant was neutral. The lower colloid was collected and vacuum dried at 30 °C for 70 h to obtain antimony tin oxide-graphene oxide nanocomposite material. (3) Mix 10 parts of modified polyamide and 0.1 parts of antimony tin oxide-graphene oxide nanocomposite material evenly, add them to a melt spinning machine for melt spinning to produce nascent fiber, and then perform post-drawing on a parallel drawing machine to obtain antistatic graphene-nylon composite fiber; wherein, the melt spinning process parameters are: the screw temperature in zone 1 is 255℃, the screw temperature in zone 2 is 270℃, the screw temperature in zone 3 is 265℃, the screw temperature in zone 4 is 265℃, the metering pump temperature is 265℃, the spinning box temperature is 265℃, the pump supply is 35g / min, the number of spinnerets is 36, the spinneret diameter is 0.4mm, the component pressure is 8MPa, and the spinning speed is 800m / min; the drawing process parameters are: the hot roller temperature is 60℃, the hot plate temperature is 120℃, and the drawing ratio is 1.5.

[0030] Example 2 A method for preparing antistatic graphene-nylon composite fiber includes the following preparation steps: (1) By mass fraction, 6 parts of diethylenetriamine and 190 parts of anhydrous ethanol were mixed evenly at 2°C, and 22 parts of bis(4-carboxyphenyl)phenylphosphine oxide were added. The mixture was stirred and reacted at 60°C for 1.5 h. After vacuum filtration, the mixture was washed 4 times with anhydrous ethanol to obtain bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt. Under a nitrogen atmosphere, by mass fraction, 32 parts of caprolactam, 0.7 parts of bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, 2.2 parts of adipic acid, and 0.95 parts of deionized water were mixed evenly and reacted at 235°C and 0.55 MPa for 4.5 h. After the pressure was reduced to atmospheric pressure, 38 parts of polyetheramine were added. 0.7 parts of sodium hypophosphite were reacted at 0.25 MPa and 245 °C for 1.25 h. The pressure was reduced to 450 Pa within 1 h and maintained for 30 min. After condensation in cooling water, the mixture was granulated to obtain pre-modified polyamide. In an ice-water bath, 150 parts of pre-modified polyamide, 5 parts of 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and 750 parts of N,N-dimethylacetamide were mixed evenly, heated to 30 °C, and stirred for 22 h. N,N-dimethylacetamide was removed by vacuum distillation. The mixture was washed 4 times with anhydrous ethanol and dried under vacuum at 55 °C for 11 h to obtain modified polyamide. (2) Under a nitrogen atmosphere, 3.2 parts of antimony tin oxide powder and 190 parts of deionized water were mixed evenly and ultrasonically dispersed for 50 min. 190 parts of 50 wt% ethanol aqueous solution and 22 parts of 3-aminopropyltriethoxysilane were added and stirred at 55 °C for 9 h. The mixture was washed 4 times each with anhydrous ethanol and deionized water, filtered, and vacuum dried at 45 °C for 11 h to obtain modified antimony tin oxide. 0.25 parts of modified antimony tin oxide and 100 parts of 10 g / L graphene oxide aqueous solution were added to 10 wt% sodium hydroxide aqueous solution to adjust the pH to 9.5. The mixture was centrifuged at 2000 r / min for 15 min with deionized water. The resulting upper suspension was centrifuged at 5000 r / min and washed until the pH of the supernatant was neutral. The lower colloid was collected and vacuum dried at 35 °C for 71 h to obtain antimony tin oxide-graphene oxide nanocomposite material. (3) Mix 12 parts of modified polyamide and 0.15 parts of antimony tin oxide-graphene oxide nanocomposite material evenly, add them to a melt spinning machine for melt spinning to produce nascent fiber, and then perform post-drawing on a parallel drawing machine to obtain antistatic graphene-nylon composite fiber; wherein, the melt spinning process parameters are: the screw temperature in zone 1 is 255℃, the screw temperature in zone 2 is 270℃, the screw temperature in zone 3 is 265℃, the screw temperature in zone 4 is 265℃, the metering pump temperature is 265℃, the spinning box temperature is 265℃, the pump supply is 35g / min, the number of spinnerets is 36, the spinneret diameter is 0.4mm, the component pressure is 9MPa, and the spinning speed is 800m / min; the drawing process parameters are: the hot roller temperature is 60℃, the hot plate temperature is 120℃, and the drawing ratio is 2.

[0031] Example 3 A method for preparing antistatic graphene-nylon composite fiber includes the following preparation steps: (1) By mass fraction, 7 parts of diethylenetriamine and 200 parts of anhydrous ethanol were mixed evenly at 4°C, and 25 parts of bis(4-carboxyphenyl)phenylphosphine oxide were added. The mixture was stirred and reacted at 65°C for 2 hours. The mixture was filtered under reduced pressure and washed 5 times with anhydrous ethanol to obtain bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt. Under a nitrogen atmosphere, by mass fraction, 35 parts of caprolactam, 0.8 parts of bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, 2.5 parts of adipic acid, and 1.0 parts of deionized water were mixed evenly and reacted at 240°C and 0.6 MPa for 5 hours. The pressure was reduced to atmospheric pressure, and 40 parts of polyetheramine and 0. Eight parts of sodium hypophosphite were reacted at 0.3 MPa and 250 °C for 1.5 h. The pressure was then reduced to 500 Pa within 1 h and maintained for 40 min. After condensation in cooling water, the mixture was pelletized to obtain pre-modified polyamide. In an ice-water bath, 200 parts of pre-modified polyamide, 5.5 parts of 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and 1000 parts of N,N-dimethylacetamide were mixed evenly, heated to 35 °C, and stirred for 24 h. The N,N-dimethylacetamide was removed by vacuum distillation, and the mixture was washed five times with anhydrous ethanol and dried under vacuum at 60 °C for 12 h to obtain modified polyamide. (2) Under a nitrogen atmosphere, 3.5 parts of antimony tin oxide powder and 200 parts of deionized water were mixed evenly and ultrasonically dispersed for 60 min. 200 parts of 50 wt% ethanol aqueous solution and 25 parts of 3-aminopropyltriethoxysilane were added and stirred at 60 °C for 10 h. The mixture was washed 5 times each with anhydrous ethanol and deionized water, filtered, and vacuum dried at 50 °C for 12 h to obtain modified antimony tin oxide. 0.3 parts of modified antimony tin oxide and 120 parts of 10 g / L graphene oxide aqueous solution were added to 10 wt% sodium hydroxide aqueous solution to adjust the pH to 10. The mixture was centrifuged at 2000 r / min for 20 min with deionized water. The resulting upper suspension was centrifuged at 5000 r / min and washed until the pH of the supernatant was neutral. The lower colloid was removed and vacuum dried at 40 °C for 72 h to obtain antimony tin oxide-graphene oxide nanocomposite material. (3) Mix 15 parts of modified polyamide and 0.2 parts of antimony tin oxide-graphene oxide nanocomposite material evenly, add them to a melt spinning machine for melt spinning to produce nascent fiber, and then perform post-drawing on a parallel drawing machine to obtain antistatic graphene-nylon composite fiber; wherein, the melt spinning process parameters are: the screw temperature in zone 1 is 255℃, the screw temperature in zone 2 is 270℃, the screw temperature in zone 3 is 265℃, the screw temperature in zone 4 is 265℃, the metering pump temperature is 265℃, the spinning box temperature is 265℃, the pump supply is 35g / min, the number of spinnerets is 36, the spinneret diameter is 0.4mm, the component pressure is 10MPa, and the spinning speed is 800m / min; the drawing process parameters are: the hot roller temperature is 60℃, the hot plate temperature is 120℃, and the drawing ratio is 2.5.

[0032] Comparative Example 1: The difference between the preparation method of the antistatic graphene-nylon composite fiber in Comparative Example 1 and Example 2 lies in the different step (1). Step (1) is modified as follows: 6 parts by mass fraction of diethylenetriamine and 190 parts by mass fraction of anhydrous ethanol are mixed evenly at 2°C, 16 parts by mass fraction of diphenyl-4,4-dicarboxylic acid are added, and the mixture is stirred and reacted at 60°C for 1.5 h. The mixture is then filtered under reduced pressure and washed 4 times with anhydrous ethanol to obtain diphenyl-4,4-dicarboxylic acid-diethylenetriamine salt. Under a nitrogen atmosphere, 32 parts by mass fraction of caprolactam, 0.7 parts by mass fraction of diphenyl-4,4-dicarboxylic acid-diethylenetriamine salt, 2.2 parts by mass fraction of adipic acid, and 0.95 parts by mass fraction of deionized water are mixed evenly and reacted at 235°C and 0.55 MPa. After 4.5 hours, the pressure was reduced to atmospheric pressure, and 38 parts of polyetheramine and 0.7 parts of sodium hypophosphite were added. The reaction was carried out at 0.25 MPa and 245 °C for 1.25 hours. The pressure was then reduced to 450 Pa within 1 hour and maintained for 30 minutes. After condensation in cooling water, the mixture was pelletized to obtain pre-modified polyamide. In an ice-water bath, 150 parts of pre-modified polyamide, 5 parts of 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and 750 parts of N,N-dimethylacetamide were mixed evenly, heated to 30 °C, and stirred for 22 hours. N,N-dimethylacetamide was removed by vacuum distillation, and the mixture was washed four times with anhydrous ethanol and dried under vacuum at 55 °C for 11 hours to obtain modified polyamide. The remaining steps were the same as in Example 2.

[0033] Comparative Example 2: The difference between the preparation method of the antistatic graphene-nylon composite fiber in Comparative Example 2 and that in Example 2 lies in the different step (1). Step (1) is modified as follows: 6 parts by mass fraction of diethylenetriamine and 190 parts by mass fraction of anhydrous ethanol are mixed evenly at 2°C, 22 parts by mass fraction of bis(4-carboxyphenyl)phenylphosphine oxide are added, and the mixture is stirred and reacted at 60°C for 1.5 h. The mixture is then filtered under reduced pressure and washed four times with anhydrous ethanol to obtain bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt. Under a nitrogen atmosphere, 32 parts by mass fraction of caprolactam, 0.7 parts by mass fraction of bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, 2.2 parts by mass fraction of adipic acid, and 0.95 parts by mass fraction of deionized water are mixed evenly at 235°C. The reaction was carried out at 0.55 MPa for 4.5 h, then the pressure was reduced to atmospheric pressure, and 0.7 parts of sodium hypophosphite were added. The reaction was then carried out at 0.25 MPa and 245 °C for 1.25 h. The pressure was reduced to 450 Pa within 1 h and maintained for 30 min. After condensation in cooling water, the mixture was pelletized to obtain pre-modified polyamide. In an ice-water bath, 150 parts of pre-modified polyamide, 5 parts of 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and 750 parts of N,N-dimethylacetamide were mixed evenly, heated to 30 °C, and stirred for 22 h. N,N-dimethylacetamide was removed by vacuum distillation, and the mixture was washed four times with anhydrous ethanol. The mixture was then dried under vacuum at 55 °C for 11 h to obtain modified polyamide. The remaining steps were the same as in Example 2.

[0034] Comparative Example 3: The difference between the preparation method of the antistatic graphene-nylon composite fiber in Comparative Example 3 and Example 2 lies in the different step (1). Step (1) is modified as follows: 6 parts by mass fraction of diethylenetriamine and 190 parts by mass fraction of anhydrous ethanol are mixed evenly at 2°C, 22 parts by mass fraction of bis(4-carboxyphenyl)phenylphosphine oxide are added, and the mixture is stirred and reacted at 60°C for 1.5 h. The mixture is then filtered under reduced pressure and washed 4 times with anhydrous ethanol to obtain bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt. Under a nitrogen atmosphere, by mass fraction of 6 parts by mass fraction of bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt is prepared. Based on fractional measurements, 32 parts of caprolactam, 0.7 parts of bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, 2.2 parts of adipic acid, and 0.95 parts of deionized water were mixed evenly and reacted at 235°C and 0.55 MPa for 4.5 h. The pressure was then reduced to atmospheric pressure, and 38 parts of polyetheramine and 0.7 parts of sodium hypophosphite were added. The reaction was carried out at 0.25 MPa and 245°C for 1.25 h. The pressure was then reduced to 450 Pa within 1 h and maintained for 30 min. After condensation in cooling water, the mixture was pelletized to obtain the modified polyamide. The remaining steps were the same as in Example 2.

[0035] Comparative Example 4: The preparation method of the antistatic graphene-nylon composite fiber in Comparative Example 4 differs from that in Example 2 in that step (2) is omitted, and step (3) is modified as follows: 12 parts of modified polyamide and 0.15 parts of graphene oxide are mixed evenly and added to a melt spinning machine for melt spinning to produce nascent fibers. The nascent fibers are then post-drawn on a parallel drawing machine to obtain antistatic graphene-nylon composite fibers. The melt spinning process parameters are: the screw temperature in zone one is 255°C. The temperature of the screw in zone two is 270℃, the temperature of the screw in zone three is 265℃, the temperature of the screw in zone four is 265℃, the temperature of the metering pump is 265℃, the temperature of the spinning box is 265℃, the pump supply is 35g / min, the number of spinnerets is 36, the diameter of the spinnerets is 0.4mm, the component pressure is 9MPa, and the spinning speed is 800m / min; the drafting process parameters are: hot roller temperature is 60℃, hot plate temperature is 120℃, and the draft ratio is 2. The remaining steps are the same as in Example 2.

[0036] Test Example 1: Antistatic performance test: The antistatic graphene-nylon composite fibers prepared in each example and comparative example were used to make the half-life of the fibers according to GB / T12703.1-2008 "Evaluation of electrostatic properties of textiles - Part 1: Static voltage half-life". Each group was tested three times and the average value was calculated.

[0037] The results are shown in Table 1.

[0038]

[0039] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 1 reveals that the antistatic graphene-nylon composite fiber prepared by this invention has good antistatic properties.

[0040] By comparison, the half-life of Examples 1-3 is shorter than that of Comparative Example 2, indicating that the reaction of caprolactam with bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, adipic acid, and deionized water, followed by reaction with polyetheramine to obtain polyamide-polyether block copolymer, allows the charge transfer effect of the ether oxygen atoms in the polyetheramine chain and the hydrophilicity of the polyether to allow the charge accumulated in the fiber to be quickly released, thereby improving the antistatic properties of the antistatic graphene-nylon composite fiber.

[0041] By comparison, the half-life of Examples 1-3 is shorter than that of Comparative Example 4, indicating that antimony tin oxide is an N-type semiconductor doped with Sb by SnO2, which has high conductivity, wear resistance, and corrosion resistance. Using graphene oxide as a precursor, antimony tin oxide is anchored onto graphene oxide sheets by 3-aminopropyltriethoxysilane to prepare a tin antimony oxide-graphene oxide nanocomposite material with high specific surface area, water dispersibility, and conductivity. After being mixed with modified polyamide and melt-spun, the antistatic properties of the antistatic graphene-nylon composite fiber are further improved.

[0042] Test Example 2: Flame retardant performance test: The antistatic graphene-nylon composite fibers prepared in each embodiment and comparative example were woven into plain weave fabrics. The limiting oxygen index was tested according to GB / T5454-1997 "Test for Burning Performance of Textiles - Oxygen Index Method". Each set of data was measured three times and the average value was taken.

[0043] The results are shown in Table 2.

[0044]

[0045] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 2 reveals that the antistatic graphene-nylon composite fiber prepared by this invention has good flame retardant properties.

[0046] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 1, indicating that the reaction of bis(4-carboxyphenyl)phenylphosphine oxide with diethylenetriamine to prepare bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt can participate in the polymerization reaction as a reactive flame retardant. During combustion, phosphorus can promote char formation, capture free radicals, and synergistically retard flame with nitrogen on polyamide molecules, thereby improving the flame retardant performance of antistatic graphene-nylon composite fibers.

[0047] Test Example 3: Anti-aging performance test: The antistatic graphene-nylon composite fibers prepared in each embodiment and comparative example were spun into stable fabrics, and the ultraviolet protection factor (UPF) was calculated with reference to GB / T18830-2009 "Evaluation of UV protection performance of textiles".

[0048] The results are shown in Table 3.

[0049]

[0050] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 3 reveals that the antistatic graphene-nylon composite fiber prepared by this invention has good anti-aging properties.

[0051] By comparison, the UPF of Examples 1-3 is greater than that of Comparative Example 3, indicating that the benzotriazole group can absorb ultraviolet light and convert it into heat energy. The secondary amine on the pre-modified polyamide undergoes a Michael addition reaction with the unsaturated double bond on 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and the ultraviolet absorber with double bond is covalently grafted onto the polyamide molecular chain, which inhibits the polyamide molecular chain breakage, yellowing and mechanical property degradation caused by ultraviolet light, and improves the anti-aging performance of antistatic graphene-nylon composite fiber.

[0052] By comparison, the UPF of Examples 1-3 is greater than that of Comparative Example 4, indicating that antimony tin oxide has a good blocking effect on ultraviolet light, which further improves the anti-aging performance of antistatic graphene-nylon composite fiber.

[0053] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing antistatic graphene-nylon composite fiber, characterized in that, The preparation method includes the following steps: (1) Mix the modified antimony tin oxide and graphene oxide aqueous solution evenly, add sodium hydroxide aqueous solution to adjust the pH, centrifuge with deionized water, centrifuge and wash the upper suspension until neutral, collect the lower colloid, dry, and obtain antimony tin oxide-graphene oxide nanocomposite material. (2) Modified polyamide and antimony tin oxide-graphene oxide nanocomposite materials were mixed, melt-spun and drawn to obtain antistatic graphene-nylon composite fiber.

2. The method for preparing antistatic graphene-nylon composite fiber according to claim 1, characterized in that, In step (1), the modified tin antimony oxide is prepared by modifying tin antimony oxide with 3-aminopropyltriethoxysilane.

3. The method for preparing antistatic graphene-nylon composite fiber according to claim 1, characterized in that, In step (1), the mass ratio of the modified antimony tin oxide to the graphene oxide aqueous solution is (0.2~0.3):(80~120); the pH adjustment is to adjust the pH to 9~10.

4. The method for preparing antistatic graphene-nylon composite fiber according to claim 1, characterized in that, The preparation steps of the modified polyamide in step (2) are as follows: pre-modified polyamide, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole and N,N-dimethylacetamide are mixed in an ice-water bath, heated and stirred to react, and after the reaction is completed, the mixture is distilled under reduced pressure, washed and dried to obtain the modified polyamide.

5. The method for preparing antistatic graphene-nylon composite fiber according to claim 1, characterized in that, In step (2), the mass ratio of the modified polyamide and the antimony tin oxide-graphene oxide nanocomposite material is (10~15):(0.1~0.2); the process parameters for melt spinning are: screw temperature in zone 1 is 255℃, screw temperature in zone 2 is 270℃, screw temperature in zone 3 is 265℃, screw temperature in zone 4 is 265℃, metering pump temperature is 265℃, spinning box temperature is 265℃, pump supply is 35g / min, number of spinnerets is 36, spinneret diameter is 0.4mm, component pressure is 8~10MPa, and spinning speed is 800m / min; the process parameters for drawing are: hot roller temperature is 60℃, hot plate temperature is 120℃, and drawing ratio is 1.5~2.

5.

6. The method for preparing antistatic graphene-nylon composite fiber according to claim 4, characterized in that, The preparation steps of the pre-modified polyamide are as follows: under a nitrogen atmosphere, caprolactam, bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, adipic acid, and deionized water are mixed and heated under pressure. After the reaction is completed, the pressure is reduced to atmospheric pressure, polyetheramine and sodium hypophosphite are added, and the reaction is heated and pressurized again. After the reaction is completed, the pressure is reduced and maintained for a certain period of time. After condensation in cooling water, the mixture is pelletized to obtain the pre-modified polyamide.

7. The method for preparing antistatic graphene-nylon composite fiber according to claim 4, characterized in that, The mass ratio of the pre-modified polyamide, 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, and N,N-dimethylacetamide is (100~200):(4.5~5.5):(500~1000); the heating and stirring reaction is carried out at 25~35℃ for 20~24h.

8. The method for preparing antistatic graphene-nylon composite fiber according to claim 6, characterized in that, The mass ratio of caprolactam, bis(4-carboxyphenyl)phenylphosphine oxide-diethylenetriamine salt, adipic acid, deionized water, polyetheramine, and sodium hypophosphite is (30~35):(0.6~0.8):(2~2.5):(0.9~1.0):(35~40):(0.6~0.8); the heating and pressurizing reaction temperature is 230~240℃, the pressure is 0.5~0.6MPa, and the reaction time is 4~5h; the reheating and pressurizing reaction temperature is 240~250℃, the pressure is 0.2~0.3MPa, and the reaction time is 1~1.5h; the depressurization and maintenance for a certain period of time is to reduce the pressure to 400~500Pa within 1h and maintain it for 20~40min.

9. An antistatic graphene-nylon composite fiber prepared by the method according to any one of claims 1 to 8.

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