Preparation method of long-acting hydrophilic antistatic PET (Polyethylene Terephthalate) fiber

Abstract

The invention discloses a preparation method of a long-acting hydrophilic antistatic PET (Polyethylene Terephthalate) fiber, which adopts the steps of electrostatic spinning, functional modification, coating curing and the like to form a uniform and stable functional interface layer on the surface of the fiber so as to obtain the long-acting hydrophilic antistatic PET fiber with high mechanical property. According to the preparation method, an electrostatic spinning process is combined with a photo-crosslinking technology to prepare the cross-linked PET fiber, amino acid is utilized to carry out surface modification on the PET fiber, then a stable functional interface layer is constructed through gelatin coating-cross-linking curing, the prepared PET fiber shows long-acting antistatic property and hydrophilicity, and meanwhile, the high mechanical strength of the PET fiber is reserved.

Description

Technical Field

[0001] The invention relates to the technical field of fiber modification, and in particular to a method for preparing long-lasting hydrophilic antistatic PET fiber. Background Art

[0002] Compared with traditional melt spinning, PET electrospinning does not require high-temperature melting, can produce ultrafine fibers with lower energy consumption, and significantly improves specific surface area and functionalization potential; compared with solution spinning, electrospinning uses less solvent, has better environmental performance, and can control fiber diameter more accurately. These characteristics make it have broad application prospects in the fields of long-lasting antistatic functional materials, hydrophilic textiles, high-efficiency filtration materials and medical dressings.

[0003] However, PET functional fibers still have the following shortcomings: 1. Strict spinning process requirements: Due to the high crystallinity and chemical inertness of PET, its solution spinning process places extremely high demands on parameter optimization, especially in terms of viscosity adjustment and solution uniformity control, which has a significant impact on the fiber forming quality and mechanical properties, and increases the complexity of the process; 2. Insufficient hydrophilicity: The lack of hydrophilic groups in the PET molecular structure leads to poor hygroscopicity, which not only affects the comfort of the fiber, but also limits its wide use in application fields that require high hygroscopicity; 3. Prominent static electricity problems: PET fibers are prone to static electricity accumulation after friction. This characteristic affects comfort when worn, and may cause equipment damage or safety hazards in sensitive fields such as electronic manufacturing and medical health; 4. Limitations of existing antistatic modification methods: Commonly used antistatic modification methods (such as surfactants and conductive fillers) have the problem of non-persistent antistatic effects, and usually lead to a decrease in the mechanical properties of the fiber. Although traditional hydrophilic modification methods (such as surface coating and chemical grafting) can improve hydrophilicity, the coating is easy to fall off and the stability is insufficient. In addition, the complex processes of these methods limit the feasibility of their industrial applications.

[0004] The Chinese invention with the authorization announcement number CN112281253B discloses "A parallel PET / PBT two-component antistatic and anti-ultraviolet fiber and its preparation method". The composite fiber obtained without damaging the mechanical properties has antistatic and anti-ultraviolet functions. Although the parallel fiber structure gives good antistatic properties, the uniformity of the distribution of the conductive functional powder and the migration after long-term use may cause the antistatic performance to decline. The Chinese invention with the authorization announcement number CN115305720B discloses "A method for preparing hydrophilic functional fabrics using polyester fiber aminated derivatives". The invention gives waste polyester fibers a significant improvement in hydrophilicity through aminolysis and cross-linking technology, but its long-term effectiveness is insufficient. The applied hydrophilic coating may gradually fall off under repeated cleaning, friction and mechanical stress, and the cross-linked product may also undergo chemical degradation or performance degradation in harsh environments such as high temperature, resulting in the difficulty of maintaining the hydrophilic effect stably for a long time. These problems limit the durability and reliability of this method in practical applications.

[0005] In view of this, the inventor of this case conducted in-depth research, which resulted in the creation of this case. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a long-lasting hydrophilic antistatic PET fiber, which adopts an electrospinning preparation process, forms a uniform and stable functional interface layer on the fiber surface through amino acid surface modification and gelatin coating and curing steps, and obtains a long-lasting hydrophilic antistatic PET fiber with high mechanical properties.

[0007] In order to achieve the above object, the solution of the present invention is: A method for preparing a long-lasting hydrophilic antistatic PET fiber, characterized in that it comprises the following steps: Step 1: Electrospinning: First, PET is dissolved in an organic solvent, and condensed and refluxed at 85°C for 0.5-1.5 h. After PET is dissolved, an antistatic agent and a photoinitiator are added respectively, and condensed and refluxed at 85°C for 0.5-1.5 h to obtain a mixed spinning solution for standby use. Then, the mixed spinning solution is transferred to a syringe, and the electrospinning conditions are controlled to perform electrospinning. After the mixed spinning solution is formed into fibers, the photocrosslinking conditions are controlled to perform photocrosslinking. Step 2: Amino acid surface modification: Then, the cross-linked PET fiber is immersed in a 0.3-1 M NaOH solution for saponification reaction; then, a 2% (w / v) HCl solution is added for neutralization, and then washed with deionized water until neutral for use; then, 0.5%-7% (w / v) functional modifier is added for functional modification, the material-liquid ratio is 1:10-30, the reaction temperature is 70-90°C, the reaction time is 20-60 min, the ultrasonic frequency is 20-40 kHz, and then washed with deionized water for multiple times, and dried at 70-90°C for 1-2 h to obtain functionalized PET fiber; wherein the functional modifier is one or two of aqueous solutions of lysine, aspartic acid, serine, tyrosine and cysteine; Step 3: Gelatin coating and curing: Then, a gelatin aqueous solution accounting for 3% to 12% of the fiber weight and a stabilizing agent accounting for 0.2% to 2.0% of the fiber weight are added to the functionalized PET fiber for coating treatment. After the treatment, the fiber is vacuum dried at 60 to 100° C. for 0.5 to 1 h, and finally cured at 130 to 150° C. for 1 to 10 min to obtain the long-lasting hydrophilic antistatic PET fiber.

[0008] In step 1, the relative molecular mass of the PET is 12000-20000 g / moL, the organic solvent is a mixed solvent of trifluoroacetic acid and dichloromethane, and the volume ratio of trifluoroacetic acid to dichloromethane in the organic solvent is 1-3:1.

[0009] In step 1, the amount of organic solvent added is 100 wt %, the amount of PET added is 1 wt %~15 wt %, the amount of the antistatic agent added is 1 wt %~10 wt %, the amount of the photoinitiator added is 0.2 wt %~5 wt %.

[0010] In step 1, the antistatic agent is one or both of polyaniline and polypyrrole, and the photoinitiator is one or both of 4,4'-bis(diethylamino)benzophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone and 1-hydroxycyclohexylphenyl ketone.

[0011] In step 1, the electrospinning conditions are: voltage of 10-20 kV, injection speed of 3-6 mL / h, spinning distance of 15-20 cm, temperature of 25-30 °C, and relative humidity of 40%-60%.

[0012] In step 1, the conditions for photocrosslinking are: 365 nm ultraviolet light, power of 10-15 mW / cm², and curing time of 10-100 s.

[0013] In step 2, the conditions of the saponification reaction are: reaction temperature of 50-90°C, time of 20-40 min, solid-liquid ratio of 1:30-80, and ultrasonic frequency of 20-40 kHz; the conditions of the neutralization are: neutralization time of 1-2 h, and solid-liquid ratio of 1:30-80.

[0014] In step 3, the mass fraction of the gelatin aqueous solution is 1% to 15%, and the stabilizing agent is one or two of azelaic acid, citric acid, gallic acid and polyethylene glycol.

[0015] In step 3, the coating treatment conditions are: treatment temperature is 30-70° C., ultrasonic frequency is 20-40 kHz, and treatment time is 12-15 min.

[0016] After adopting the above technical scheme, the preparation method of a long-lasting hydrophilic antistatic PET fiber of the present invention has the following beneficial effects: 1. The present invention firstly adds an antistatic agent (such as polyaniline) into the PET photo-crosslinking system, utilizes the π-conjugated structure and doping effect of polyaniline to form a stable conductive network, and greatly reduces the resistivity of the material; the photo-crosslinking system further stabilizes the distribution and binding of the antistatic agent in the PET matrix, prevents the loss or migration of the antistatic agent, and thus achieves long-term antistatic performance; at the same time, the photo-crosslinking process improves the breaking strength of the fiber by enhancing the binding force between molecular chains and the uniformity of the network structure; 2. The present invention adopts photocrosslinking technology combined with environmentally friendly photoinitiators, avoiding the problems of high toxicity and difficult removal of residuals of traditional chemical crosslinkers. The ultraviolet light crosslinking process is efficient and fast, and can achieve crosslinking fixation in a short time, thereby improving the bonding strength and functional stability of the fiber membrane, meeting the requirements of green environmental protection and efficient production; 3. Then, through caustic soda saponification and amino acid functional modification technology, the present invention introduces amino groups (-NH 2 ) and carboxyl (-COOH) functional groups, and then further enhance the hydrophilicity of the fiber through gelatin coating-crosslinking curing, while improving the softness and biocompatibility of PET fiber, making it more suitable for applications in medical and intimate textiles. 4. The present invention significantly enhances the binding force between modified materials (such as antistatic agents, gelatin) and the surface of PET fibers by constructing a cross-linked network and a chemically bonded structure, effectively overcoming the problem of poor durability of traditional antistatic / hydrophilic finishing. This method ensures that the fiber can still maintain excellent antistatic and hydrophilic properties after long-term use and multiple washings, giving it more stable functional durability.

[0017] In general, the PET fiber prepared by the present invention has long-lasting antistatic properties, long-lasting hydrophilicity, biocompatibility and softness, stable functions, environmental protection and high efficiency. The material is suitable for multiple fields such as filter materials, medical dressings, electronic protection, functional textiles, etc., meets the diverse needs of modern high-performance materials, and shows broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a modification mechanism diagram of the PET fiber of Example 4 of the present invention (the fiber in the figure represents the PET fiber, and the groups on the PET fiber represent the groups on the surface of the fiber after modification); Figure 2 PET fiber thickness diagram of the embodiment of the present invention and the comparative example; Figure 3 3 are scanning electron microscope images of the PET fibers of the present invention, wherein a) is the long-lasting hydrophilic antistatic PET fiber prepared in Example 4, and b) is the PET fiber prepared in Comparative Example 10. DETAILED DESCRIPTION

[0019] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0020] 1. Preparation of Fiber Example 1 A method for preparing a long-lasting hydrophilic antistatic PET fiber comprises the following steps: Step 1: Electrospinning: First, PET with a relative molecular mass of 12000-20000 g / moL was dissolved in a mixed solvent of trifluoroacetic acid and dichloromethane (volume ratio of 3:1), and condensed and refluxed at 85°C for 0.5 h. After the PET was dissolved, polypyrrole and 1-hydroxycyclohexyl phenyl ketone were added respectively, and condensed and refluxed at 85°C for 0.5 h to obtain a mixed spinning solution for standby use, wherein the mixed solvent: PET: polypyrrole: 1-hydroxycyclohexyl phenyl ketone (mass ratio) = 100:8:3.5:0.8; Then the mixed spinning solution was transferred to a syringe, and the electrospinning conditions were controlled as follows: voltage of 18 kV, injection speed of 5.5 mL / h, spinning distance of 17 cm, temperature of 25 °C, and relative humidity of 55%. After the mixed spinning solution was fiberized, it was photo-crosslinked, and the photo-crosslinking conditions were controlled as follows: 365 nm ultraviolet light, power of 13 mW / cm², and curing time of 65 s to obtain cross-linked PET fibers. Step 2: Amino acid surface modification: Then the cross-linked PET fiber was immersed in 1 M NaOH solution for saponification reaction, the reaction temperature was 70 ° C, the time was 25 min, the solid-liquid ratio was 1:50 (the liquid was deionized water), and the ultrasonic frequency was 25 kHz; then 2% (w / v) HCl solution was added for neutralization, the neutralization time was 1.5 h, the solid-liquid ratio was 1:40 (the liquid was deionized water), and then washed with deionized water until neutral for use; then 4% (w / v) lysine was added for functional modification, the solid-liquid ratio was 1:20 (the liquid was deionized water), the reaction temperature was 85 ° C, the reaction time was 30 min, the ultrasonic frequency was 28 kHz, and then washed with deionized water three times and dried at 80 ° C for 1 h to obtain functionalized PET fiber; Step 3: Gelatin coating and curing: Then, 6.5% gelatin (the mass fraction of the gelatin aqueous solution is 7%) and 1.0% polyethylene glycol (the mass fraction of the PET fiber) were added to the functionalized PET fiber for coating treatment. The treatment temperature was 50°C, the ultrasonic frequency was 28 kHz, and the treatment time was 15 min. After the treatment, it was vacuum dried at 70°C for 1 h and finally cured at 135°C for 3 min to obtain the long-lasting hydrophilic antistatic PET fiber.

[0021] Example 2 A method for preparing a long-lasting hydrophilic antistatic PET fiber comprises the following steps: Step 1: Electrospinning: First, PET with a relative molecular mass of 12000-20000 g / moL was dissolved in a mixed solvent of trifluoroacetic acid and dichloromethane (volume ratio of 3:1), and condensed and refluxed at 85°C for 0.5 h. After the PET was dissolved, polyaniline and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone were added respectively, and condensed and refluxed at 85°C for 0.5 h to obtain a mixed spinning solution for standby use, wherein the mixed solvent: PET: polyaniline: 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (mass ratio) = 100:6:2:0.7; Then the mixed spinning solution was transferred to a syringe, and the electrospinning conditions were controlled as follows: voltage of 18 kV, injection speed of 5 mL / h, spinning distance of 17 cm, temperature of 25 °C, and relative humidity of 55%. After the mixed spinning solution was fiberized, it was photo-crosslinked, and the photo-crosslinking conditions were controlled as follows: 365 nm ultraviolet light, power of 13 mW / cm², and curing time of 45 s to obtain cross-linked PET fibers. Step 2: Amino acid surface modification: Then the cross-linked PET fiber was immersed in 1 M NaOH solution for saponification reaction, the reaction temperature was 70 ° C, the time was 25 min, the solid-liquid ratio was 1:50 (the liquid was deionized water), and the ultrasonic frequency was 25 kHz; then 2% (w / v) HCl solution was added for neutralization, the neutralization time was 1.5 h, the solid-liquid ratio was 1:40 (the liquid was deionized water), and then washed with deionized water until neutral for use; then 4% (w / v) serine was added for functional modification, the solid-liquid ratio was 1:20 (the liquid was deionized water), the reaction temperature was 85 ° C, the reaction time was 30 min, the ultrasonic frequency was 28 kHz, and then washed with deionized water three times and dried at 80 ° C for 1 h to obtain functionalized PET fiber; Step 3: Gelatin coating and curing: Then, 6% gelatin (the mass fraction of the gelatin aqueous solution is 7.5%) and 1.5% azelaic acid (the mass fraction of the PET fiber) were added to the functionalized PET fiber for coating treatment. The treatment temperature was 60°C, the ultrasonic frequency was 28 kHz, and the treatment time was 12 min. After the treatment, it was vacuum dried at 70°C for 1 h and finally cured at 145°C for 3 min to obtain the long-lasting hydrophilic antistatic PET fiber.

[0022] Example 3 A method for preparing a long-lasting hydrophilic antistatic PET fiber comprises the following steps: Step 1: Electrospinning: First, PET with a relative molecular mass of 12000-20000 g / moL is dissolved in a mixed solvent of trifluoroacetic acid and dichloromethane (volume ratio of 2:1), and condensed and refluxed at 85°C for 0.5 h. After the PET is dissolved, polyaniline and 4,4'-bis(diethylamino)benzophenone are added respectively, and condensed and refluxed at 85°C for 0.5 h to obtain a mixed spinning solution for standby use, wherein the mixed solvent: PET: polyaniline: 4,4'-bis(diethylamino)benzophenone (mass ratio) = 100:5:1:0.6; Then the mixed spinning solution was transferred to a syringe, and the electrospinning conditions were controlled as follows: voltage of 18 kV, injection speed of 3 mL / h, spinning distance of 17 cm, temperature of 25 °C, and relative humidity of 55%. After the mixed spinning solution was fiberized, it was photo-crosslinked, and the photo-crosslinking conditions were controlled as follows: 365 nm ultraviolet light, power of 13 mW / cm², and curing time of 50 s to obtain cross-linked PET fibers. Step 2: Amino acid surface modification: Then the cross-linked PET fiber was immersed in 0.6 M NaOH solution for saponification reaction, the reaction temperature was 70 ° C, the time was 30 min, the solid-liquid ratio was 1:50 (the liquid was deionized water), and the ultrasonic frequency was 25 kHz; then 1.5% (w / v) HCl solution was added for neutralization, the neutralization time was 1.5 h, the solid-liquid ratio was 1:40 (the liquid was deionized water), and then washed with deionized water until neutral for use; then 5% (w / v) lysine was added for functional modification, the solid-liquid ratio was 1:20 (the liquid was deionized water), the reaction temperature was 85 ° C, the reaction time was 30 min, the ultrasonic frequency was 28 kHz, and then washed with deionized water three times and dried at 70 ° C for 2 h to obtain functionalized PET fiber; Step 3: Gelatin coating and curing: Then, 7.5% gelatin water (the mass fraction of the gelatin aqueous solution is 8%) and 1.0% polyethylene glycol (the mass fraction of the PET fiber) were added to the functionalized PET fiber for coating treatment. The treatment temperature was 55°C, the ultrasonic frequency was 28 kHz, and the treatment time was 15 min. After the treatment, it was vacuum dried at 70°C for 1 h and finally cured at 155°C for 3 min to obtain the long-lasting hydrophilic antistatic PET fiber.

[0023] Example 4 A method for preparing a long-lasting hydrophilic antistatic PET fiber, such as Figure 1 As shown, the following steps are included: Step 1: Electrospinning: First, PET with a relative molecular mass of 12000-20000 g / moL was dissolved in a mixed solvent of trifluoroacetic acid and dichloromethane (volume ratio of 2:1), and condensed and refluxed at 85°C for 0.5 h. After the PET was dissolved, polyaniline and 4,4'-bis(diethylamino)benzophenone were added respectively, and condensed and refluxed at 85°C for 0.5 h to obtain a mixed spinning solution for standby use, wherein the mixed solvent: PET: polyaniline: 4,4'-bis(diethylamino)benzophenone (mass ratio) = 100:8:3.5:0.8; Then the mixed spinning solution was transferred to a syringe, and the electrospinning conditions were controlled as follows: voltage of 18 kV, injection speed of 3 mL / h, spinning distance of 17 cm, temperature of 25 °C, and relative humidity of 55%. After the mixed spinning solution was fiberized, it was photo-crosslinked, and the photo-crosslinking conditions were controlled as follows: 365 nm ultraviolet light, power of 13 mW / cm², and curing time of 50 s to obtain cross-linked PET fibers. Step 2: Amino acid surface modification: Then the cross-linked PET fiber was immersed in 0.6 M NaOH solution for saponification reaction, the reaction temperature was 70 ° C, the time was 30 min, the solid-liquid ratio was 1:50 (the liquid was deionized water), and the ultrasonic frequency was 25 kHz; then 1.5% (w / v) HCl solution was added for neutralization, the neutralization time was 1.5 h, the solid-liquid ratio was 1:40 (the liquid was deionized water), and then washed with deionized water until neutral for use; then 5% (w / v) lysine was added for functional modification, the solid-liquid ratio was 1:20 (the liquid was deionized water), the reaction temperature was 85 ° C, the reaction time was 30 min, the ultrasonic frequency was 28 kHz, and then washed with deionized water three times and dried at 80 ° C for 1 h to obtain functionalized PET fiber; Step 3: Gelatin coating and curing: Then, 7.5% gelatin aqueous solution (the mass fraction of gelatin aqueous solution is 7%) and 1.0% polyethylene glycol (the mass fraction of PET fiber) were added to the functionalized PET fiber for coating treatment. The treatment temperature was 60°C, the ultrasonic frequency was 28 kHz, and the treatment time was 15 min. After the treatment, it was vacuum dried at 70°C for 1 h and finally cured at 155°C for 3 min to obtain the long-lasting hydrophilic antistatic PET fiber.

[0024] like Figure 3 As shown in (a), the PET fiber obtained by incorporating polyaniline into the PET photo-crosslinking system has a "grid-like" structure.

[0025] Comparative Example 1 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 1, polyaniline was not added, that is, the addition of the antistatic agent was omitted.

[0026] Comparative Example 2 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 1, 4,4'-bis(diethylamino)benzophenone was not added, that is, the addition of the photoinitiator was omitted.

[0027] Comparative Example 3 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 1, no photocrosslinking step was performed.

[0028] Comparative Example 4 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 2, no NaOH solution was added and no saponification reaction was performed.

[0029] Comparative Example 5 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 2, no HCl solution was added and no neutralization treatment was performed.

[0030] Comparative Example 6 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 2, lysine was not added, that is, the addition of the functional modifier was omitted.

[0031] Comparative Example 7 The preparation method of Example 4 was repeated according to the dosage of each component, except that all the material-liquid ratios in step 2 were changed to 1:5. Comparative Example 8 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 3, no gelatin aqueous solution was added.

[0032] Comparative Example 9 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 3, polyethylene glycol was not added, that is, the addition of the stabilizing agent was omitted.

[0033] Comparative Example 10 The preparation method of Example 4 was repeated according to the dosage of each component, except that polyaniline and photoinitiator 4,4'-bis(diethylamino)benzophenone were not added in step 1, and 5.0 wt % carbon nanotubes.

[0034] like Figure 3 b) shows that carbon nanotubes are dispersed in PET fibers.

[0035] Comparative Example 11 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 1, the electrospinning conditions were changed to: injection speed of 1 mL / h, spinning distance of 10 cm.

[0036] Comparative Example 12 First, PET with a relative molecular mass of 12000-20000 g / moL was dissolved in a mixed solvent of trifluoroacetic acid and dichloromethane (volume ratio of 2:1), and condensed and refluxed at 85°C for 0.5 h to obtain a mixed spinning solution. Then the mixed spinning solution was transferred to a syringe, and the electrospinning conditions were controlled: voltage of 18 kV, injection speed of 3 mL / h, spinning distance of 17 cm, temperature of 25°C, and relative humidity of 55% to obtain PET fibers.

[0037] Comparative Example 13 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 1, the PET fiber was not prepared by electrospinning, and the mixed solution was injected into an ethanol coagulation bath by wet spinning, the spinning speed was 3 m / min, and the photocrosslinking conditions were changed to: at 365 nm ultraviolet light, the power was 13 mW / cm², and the curing time was 28 s.

[0038] Comparative Example 14 The preparation method of Example 4 was repeated according to the dosage of each component, except that in step 1, polyaniline and photoinitiator 4,4'-bis(diethylamino)benzophenone were not added, that is, antistatic functional modification was not performed, and after the functional modification in step 3, the fiber was immersed in an aqueous solution of 3.5 wt% fiber antistatic agent LUROL AMD for 60 s and then dried at 70°C for 1 h.

[0039] In the present invention, as shown in Table 1, the raw materials used are all commercially available products.

[0040] Table 1 Raw materials and manufacturers

[0041] 2. Performance Test The PET fibers obtained in the embodiments and comparative examples were subjected to the following performance tests: 1. Hydrophilicity test: The hydrophilicity was tested using a contact angle meter, the instrument model was JC2000D1. 2 μL of water was dropped onto the film sample at least at 5 different locations, and the static contact angles of the water droplets at each location were read and the average value was taken. The results are shown in Table 2. 2. Mechanical properties test: The composite film was tested for tensile properties when the thickness of the film was 30 μm. The film was cut into strips with a length of 10 cm and a width of 1 cm. The strips were then fixed on the fixture of the testing machine. The tensile speed was set to 50 mm / min. Each group of samples was tested 5 times in parallel and the average value was taken. The results are shown in Table 2. 3. Thickness test: Use YG141D fabric thickness tester to continuously test the composite film, and the pressure value is set to 50cN / cm 2 Each sample was tested 10 times and the average value was taken. The results are shown in Figure 2 As shown; 4. Air permeability: Referring to the national standard GB / T 5453-1997, the gas permeability of the composite membrane was tested using the YGB461E fabric air permeability meter. The test pressure was set to 100 Pa. Three different positions were selected for each sample to be tested, and the average value was taken. The results are shown in Table 2. 5. Surface resistivity: The ultra-high insulation resistance tester CXT6015 was used for testing. The samples were cut into a circle with a radius of 5 cm. Each sample was tested 3 times to get the average value. The position was changed after each test. The results are shown in Table 2. 6. Washability test: The fiber (about 5×15 cm) was washed in a washing machine at 200 mL and 40±3°C for 45 minutes. The wettability of the fabric was measured after 1, 5, 10, 20 and 50 cycles of washing (cut according to the test requirements). After different washing times, the fiber sample was taken out and dried, and the surface resistivity and contact angle were tested. The results are shown in Table 3 below. 7. Durability test: The long-term use conditions are simulated by accelerated aging test. The specific test conditions are as follows: the PET fiber sample is placed in a constant temperature and humidity environment box, the temperature is set to 70±2℃, the humidity is set to 85%±5% RH, and the aging time is 500 hours. During this period, samples are taken every 100 hours to test the surface resistance and contact angle. The results are shown in Table 4 below.

[0042] Table 2 Performance characterization results of PET fibers

[0043] Table 3 Surface resistivity and contact angle of PET fibers after multiple washings

[0044] Table 4 Surface resistivity and contact angle of PET fiber after accelerated aging

[0045] The results show that the PET fibers prepared in Examples 1 to 4 have good comprehensive properties, good antistatic durability, small contact angle and good hydrophilicity, and the effects of washing and accelerated aging factors are relatively small. The antistatic PET fibers prepared in Example 4 are washed 50 times, and their surface resistivity and contact angle are not greatly improved after 500 h accelerated aging. Under different humidity environments, they all have good antistatic effects and good performance. In particular, compared with Example 1, Example 2 and Example 3, the comprehensive properties of the PET fibers prepared by the method of Example 4 are better. Therefore, cross-linked PET fibers are prepared by electrospinning technology combined with a green light curing system, and their surfaces are further modified by amino acid directional functionalization technology. Subsequently, a uniform and stable functional interface layer is successfully formed on the fiber surface by coating a modifier with gelatin and performing a curing treatment. The prepared composite PET fibers not only show excellent long-term antistatic properties and hydrophilicity, but also retain the high mechanical strength of the PET fibers.

[0046] In Comparative Example 1, polyaniline was not added in step 1, so that photocuring cross-linking could not be achieved and the conductive function of polyaniline was lacking, resulting in increased resistivity and decreased mechanical properties.

[0047] In Comparative Example 2, in step 1, no initiator is added, the cross-linking effect is reduced, the resistivity is increased, and the mechanical properties are reduced.

[0048] In Comparative Example 3, no ultraviolet irradiation was performed, the cross-linking effect was reduced, the resistivity was increased, and the mechanical properties were reduced.

[0049] In Comparative Example 4, without adding NaOH solution, the PET fiber failed to undergo hydroxylation and carboxylation, and could not be further coupled and modified, resulting in reduced hydrophilicity.

[0050] In Comparative Example 5, no HCl solution was added, and the modification effect was reduced.

[0051] In Comparative Example 6, no functional modifier was added, and the gelatin coating could not form a long-lasting coating, and the long-lasting effect was poor.

[0052] In Comparative Example 7, the material-liquid ratio is low, effective impregnation is impossible, and the modification effect is unstable.

[0053] In Comparative Example 8, gelatin was not added, and the hydrophilicity and antistatic properties decreased.

[0054] In Comparative Example 9, due to the lack of a stabilizing agent, the hydrophilicity and antistatic properties decreased.

[0055] In Comparative Example 10, no polyaniline and photoinitiator were added, and carbon nanotubes were used instead. PET could not be cross-linked and cured, and the mechanical properties were reduced. In addition, the color of the PET fiber was darker, affecting the aesthetics.

[0056] In Comparative Example 11, the electrospinning conditions were changed, but PET fibers could not be produced.

[0057] In Comparative Example 12, no modification treatment was performed after electrospinning, and the obtained PET fiber had poor antistatic properties and hydrophilicity.

[0058] In Comparative Example 13, PET fibers were prepared by conventional wet spinning, and the fibers had a relatively large thickness and a high breaking strength.

[0059] In Comparative Example 14, polyaniline and photoinitiator were not added, and 3.5wt% fiber antistatic agent LUROL AMD was used to treat the composite PET fiber. The surface resistance of the modified PET fiber was low, but after washing and accelerated aging, the surface resistivity increased significantly and the antistatic effect decreased.

[0060] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A method for preparing a long-lasting hydrophilic antistatic PET fiber, characterized in that: The following steps are involved: Step 1: Electrospinning: First, PET is dissolved in an organic solvent, and condensed and refluxed at 85°C for 0.5-1.5 h. After PET is dissolved, an antistatic agent and a photoinitiator are added respectively, and condensed and refluxed at 85°C for 0.5-1.5 h to obtain a mixed spinning solution for standby use. Then, the mixed spinning solution is transferred to a syringe, and the electrospinning conditions are controlled to perform electrospinning. After the mixed spinning solution is formed into fibers, the photocrosslinking conditions are controlled to perform photocrosslinking. Step 2: Amino acid surface modification: Then, the cross-linked PET fiber is immersed in a 0.3-1 M NaOH solution for saponification reaction; then, a 2% (w / v) HCl solution is added for neutralization, and then washed with deionized water until neutral for use; then, 0.5%-7% (w / v) functional modifier is added for functional modification, the material-liquid ratio is 1:10-30, the reaction temperature is 70-90°C, the reaction time is 20-60 min, the ultrasonic frequency is 20-40kHz, and then washed with deionized water for multiple times, and dried at 70-90°C for 1-2 h to obtain functionalized PET fiber; wherein the functional modifier is one or two of aqueous solutions of lysine, aspartic acid, serine, tyrosine and cysteine; Step 3: Gelatin coating and curing: Then, 3% to 12% of a gelatin aqueous solution and 0.2% to 2.0% of a stabilizing agent, which account for 3% to 12% of the weight of the fiber, are added to the functionalized PET fiber for coating treatment. After the treatment, the fiber is vacuum dried at 60 to 100° C. for 0.5 to 1 h, and finally cured at 130 to 150° C. for 1 to 10 min to obtain the long-lasting hydrophilic antistatic PET fiber.

2. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 1, the relative molecular mass of the PET is 12000-20000 g / moL, the organic solvent is a mixed solvent of trifluoroacetic acid and dichloromethane, and the volume ratio of trifluoroacetic acid to dichloromethane in the organic solvent is 1-3:

1.

3. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 1, the amount of organic solvent added is 100 wt %, the amount of PET added is 1 wt %~15 wt %, the amount of the antistatic agent added is 1 wt %~10 wt %, the amount of the photoinitiator added is 0.2 wt %~5 wt %.

4. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 1, the antistatic agent is one or both of polyaniline and polypyrrole, and the photoinitiator is one or both of 4,4'-bis(diethylamino)benzophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone and 1-hydroxycyclohexylphenyl ketone.

5. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 1, the electrospinning conditions are: voltage of 10-20 kV, injection speed of 3-6 mL / h, spinning distance of 15-20 cm, temperature of 25-30 °C, and relative humidity of 40%-60%.

6. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 1, the conditions for photocrosslinking are: 365 nm ultraviolet light, power of 10-15 mW / cm², and curing time of 10-100 s.

7. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 2, the conditions of the saponification reaction are: reaction temperature of 50-90°C, time of 20-40 min, solid-liquid ratio of 1:30-80, and ultrasonic frequency of 20-40 kHz; the conditions of the neutralization are: neutralization time of 1-2 h, and solid-liquid ratio of 1:30-80.

8. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 3, the mass fraction of the gelatin aqueous solution is 1% to 15%, and the stabilizing agent is one or two of azelaic acid, citric acid, gallic acid and polyethylene glycol.

9. The method for preparing a long-lasting hydrophilic antistatic PET fiber according to claim 1, characterized in that: In step 3, the coating treatment conditions are: treatment temperature is 30-70° C., ultrasonic frequency is 20-40 kHz, and treatment time is 12-15 min.

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