Preparation method and application of hydrophilic PET ultrafine powder

Abstract

The application relates to a preparation method and application of hydrophilic PET superfine powder, and the preparation method of the hydrophilic PET superfine powder is as follows: PET superfine powder is subjected to swelling and surface group activation treatment to obtain reactive PET superfine powder, then a hydrophilic finishing agent is covalently grafted to the surface of the reactive PET superfine powder through a crosslinking agent, and the hydrophilic PET superfine powder is obtained; the hydrophilic PET superfine powder is melt-blended and spun with PET chips, and the hydrophilic PET fiber is obtained; the application discards the traditional method for obtaining the PET hydrophilic fiber, proposes a new solution from the intermediate link, establishes a simple and easy method for preparing the PET hydrophilic fiber, develops the hydrophilic PET superfine powder and directly uses the same in fiber spinning, effectively improves the content of the hydrophilic group of the unit mass PET superfine powder, simultaneously improves the fastness of the hydrophilic finishing agent on the PET base material, and guarantees the durability in subsequent melt spinning and use of the finished fiber.

Description

Technical Field

[0001] This invention belongs to the field of functional chemical fiber research and development technology, and relates to a method for preparing and applying hydrophilic PET ultrafine powder. Background Technology

[0002] Polyester (PET) fiber is the most produced synthetic fiber, accounting for approximately 90% of total synthetic fiber production. PET fiber is widely used in the production of clothing fabrics and industrial products due to its excellent properties such as strength, durability, resistance to deformation, and quick-drying properties. However, because its polyester molecular structure lacks hydrophilic groups, it has poor moisture absorption and permeability, with a standard moisture regain of only 0.4%~0.5%, and even at 100% relative humidity, the moisture absorption rate is only 0.6%~0.8%, which seriously affects the comfort of polyester clothing or accessories. For industrial polyester products, PET fiber is prone to static electricity in dry environments due to its strong hydrophobicity, posing a safety hazard. Currently, traditional hydrophilic finishing methods for PET fibers are the most common, but these methods consume large amounts of water, energy, and chemicals, increasing wastewater discharge, and leaving finishing agent residues on the fabric. Furthermore, the wet processing stage of textile fibers is one of the weak links restricting my country's textile industry from moving towards high-end manufacturing. Given the increasingly stringent requirements of the textile industry for energy conservation, emission reduction, and green safety, the development of clean chemical fiber modification technologies is of great significance.

[0003] Currently, common methods to improve the hydrophilicity of PET fibers include: surface morphology modification, adsorption and fixation of hydrophilic finishing agents, and surface grafting modification.

[0004] Surface morphology modification mainly refers to the method of giving fibers irregular cross sections or uneven surface structures through various physical or chemical means, increasing the wetting and contact area of ​​water on the fiber surface, thereby improving the moisture absorption performance of polyester. However, this places higher demands on the polyester production process, making weaving difficult, inefficient, and costly, and easily producing fuzz. Although it can indirectly improve the moisture absorption performance of fiber aggregates, it does not significantly improve the moisture regain or hydrophilicity of polyester itself.

[0005] The most common and feasible finishing method is the impregnation method using hydrophilic finishing agents. Synthetic hydrophilic finishing agents include polyethylene glycol, polyester and polyether resins, epoxy resins, polysiloxanes, and polyurethanes. Reference 1 (Research on process parameters of hydrophilic softening finishing of polyester [J], Dyeing and Finishing Technology 34(2012) 12-14.) describes the use of DP-9993, a polyester polyether organosilicon ternary block copolymer finishing agent, to finish polyester fabrics. When the finishing process is 15g / L finishing agent, two dips and two nips (70%~80% nips) – pre-drying (110℃, 180s) – baking (180℃, 60s), the radial capillary effect of the polyester fabric increases from 12.5cm to 20cm, and the electrostatic half-life decreases to 0.54s. Reference 2 (Synthesis and application of hydrophilic finishing agent LS for polyester [J], Dyeing and Finishing Technology 34(2012)) 45-49.) By synthesizing a polyester polyether hydrophilic finishing agent LS using phthalic anhydride and polyethylene glycol, the wetting time of polyester fabrics can be reduced to 4.05s, and recovered to 25.81s after 5 washes. In industry, hydrophilic finishing agents such as polyester polyether, acrylic resins, hydrophilic ethylene compounds, and polyalkylene oxides are often used to synthesize hydrophilic finishing agents and treat PET fibers using the traditional impregnation method. Although the traditional wet finishing technology is mature and has a low cost, it still has problems such as high water and energy consumption and poor durability in practical applications.

[0006] Surface grafting modification is a method to obtain relatively long-lasting and effective hydrophilic properties; Reference 3 (Influence of plasma grafting reaction on hydrophilic properties of polyester fabric [J], Journal of Textile Research 31 (2010) 74-78.) uses polymer monomers and argon plasma to hydrophilically modify polyester fabrics. The surface wetting time is 2.9s, the water diffusion rate is 7.2mm / s, the fabric surface contact angle is 0, and it shows good durability after multiple washes; This type of hydrophilic finishing technology still has the following problems: (1) Most of the commonly used hydrophilic finishing agents are synthetic hydrophilic finishing agents, and their safety and ecological properties need to be further improved; (2) The commonly used method is post-immersion finishing of PET fiber or fabric, which consumes water and energy and does not meet the development requirements of green textile industry.

[0007] Recently, the research and development of functional PET masterbatches has gradually attracted the interest of enterprises. This involves adding functional materials to synthetic materials to create functional masterbatches, which are then incorporated into fibers during the spinning process to form functional fibers. These fibers offer permanent functionality and pose no environmental problems. In the functional fiber and textile development industry chain, the development of functional masterbatches is the leading link and the first link in the chain. Therefore, the research and development of functional masterbatches is crucial to the development of the entire textile industry, and its advancement will have a profound impact on the development of functional fibers and fabrics. Summary of the Invention

[0008] The purpose of this invention is to solve the problems existing in the prior art and to provide a method for preparing and applying hydrophilic PET ultrafine powder.

[0009] To achieve the above objectives, the present invention adopts the following solution:

[0010] A method for preparing hydrophilic PET ultrafine powder involves first swelling and surface group activation treatment of PET ultrafine powder to obtain reactive PET ultrafine powder, and then covalently grafting a hydrophilic finishing agent onto the surface of the reactive PET ultrafine powder using a crosslinking agent to obtain hydrophilic PET ultrafine powder.

[0011] As a preferred technical solution:

[0012] The method for preparing hydrophilic PET ultrafine powder described above has an average particle size of 5~10μm.

[0013] The method for preparing hydrophilic PET ultrafine powder as described above involves swelling and surface group activation treatment of the PET ultrafine powder. This includes: first, soaking the PET ultrafine powder in an alkaline solution to increase its swelling degree; then, soaking the PET ultrafine powder in a mixture of choline chloride, oxalic acid, and water, or a mixture of potassium carbonate, ethylene glycol, and water, to further increase its swelling degree and improve the content of reactive hydroxyl groups on the surface of the PET ultrafine powder, thereby obtaining reactive PET ultrafine powder.

[0014] The method for preparing hydrophilic PET ultrafine powder described above uses sodium hydroxide solution or potassium hydroxide solution as the alkaline solution; the concentration of the alkaline solution is 1~50 g / L; the immersion temperature in the alkaline solution is 60~95℃ and the time is 30~90 min; these parameters are set based on considerations of the swelling degree and alkali resistance stability of PET.

[0015] In a mixture of choline chloride, oxalic acid, and water, the total concentration of choline chloride and oxalic acid is 10-100 g / L, and the molar ratio of choline chloride to oxalic acid is 0.5-2:1. Setting the total concentration of choline chloride and oxalic acid in this way avoids excessive swelling and decomposition of the PET ultrafine powder due to excessive concentration, which would increase the difficulty of subsequent centrifugal purification. Conversely, setting the molar ratio of choline chloride to oxalic acid in this way avoids excessive swelling and decomposition of the PET ultrafine powder due to excessive concentration, which would increase the difficulty of subsequent centrifugal purification. Similarly, setting the molar ratio of choline chloride to oxalic acid in this way avoids excessive swelling and decomposition of the PET ultrafine powder due to excessive concentration, which would increase the difficulty of subsequent centrifugal purification.

[0016] In a mixture of potassium carbonate, ethylene glycol, and water, the total concentration of potassium carbonate and ethylene glycol is 50-150 g / L, and the molar ratio of potassium carbonate to ethylene glycol is 1:4-8. Setting the total concentration of potassium carbonate and ethylene glycol in this way avoids excessive swelling and decomposition of the PET ultrafine powder due to excessive concentration, which would increase the difficulty of subsequent centrifugal purification. Conversely, setting the molar ratio of potassium carbonate to ethylene glycol in this way avoids excessive swelling and decomposition of the PET ultrafine powder due to excessively high concentration, which would increase the difficulty of subsequent centrifugal purification. Conversely, setting the molar ratio of potassium carbonate to ethylene glycol in this way avoids excessive swelling and decomposition of the PET ultrafine powder due to excessively high concentration, which would increase the difficulty of subsequent centrifugal purification.

[0017] The soaking temperature in the mixture of choline chloride, oxalic acid and water is 40~80℃ and the time is 30~90min. This temperature and time setting can avoid poor swelling of the PET ultrafine powder surface due to too low temperature or too short time, which would make it difficult for choline chloride and oxalic acid to penetrate below the powder surface, resulting in low activation and too few reactive hydroxyl groups, affecting the subsequent grafting degree with hydrophilic finishing agent. At the same time, it can avoid severe swelling and decomposition of PET ultrafine powder due to too high temperature or too long time, which would affect the uniform mixing with other materials in melt spinning.

[0018] The immersion temperature in the mixture of potassium carbonate, ethylene glycol, and water is 60~100℃, and the time is 60~120min. This temperature and time setting can avoid poor swelling of the PET ultrafine powder surface due to excessively low temperature or short time, which would prevent potassium carbonate and ethylene glycol from penetrating below the powder surface layer, resulting in low activation and insufficient reactive hydroxyl groups, affecting the subsequent grafting degree with hydrophilic finishing agents. At the same time, it can also avoid severe swelling and decomposition of PET ultrafine powder due to excessively high temperature or long time, which would affect the uniform mixing with other materials during melt spinning.

[0019] The method for preparing hydrophilic PET ultrafine powder as described above, which involves covalently grafting a hydrophilic finishing agent onto the surface of reactive PET ultrafine powder using a crosslinking agent, refers to: immersing the reactive PET ultrafine powder in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid, and water, followed by shaking, and then pre-drying and baking sequentially, or further purifying it by centrifugation, wherein the natural polysaccharide is hyaluronic acid or water-soluble chitosan.

[0020] In the preparation method of hydrophilic PET ultrafine powder as described above, the total concentration of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water in the mixture is 20~60 g / L. This total concentration can avoid reducing the content of hydrophilic groups in the PET ultrafine powder due to being too low, thereby affecting the hydrophilicity of the spun yarn. At the same time, it can avoid wasting hydrophilic finishing agents and making it difficult to remove impurities due to being too high. The molar ratio of polyethylene glycol, natural polysaccharide and butanetetracarboxylic acid is 1:2~5:1~8. In the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, polyethylene glycol and natural polysaccharide mainly play a hydrophilic role. Butanetetracarboxylic acid is used to crosslink the two hydrophilic agents to PET. Therefore, the amount of butanetetracarboxylic acid is slightly higher than that of polyethylene glycol and natural polysaccharide. Considering that the thermal stability of natural polysaccharide is better than that of polyethylene glycol during melt spinning, the amount of natural polysaccharide is slightly higher than that of polyethylene glycol.

[0021] The immersion and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 90~100℃. This temperature setting can avoid poor durability due to low grafting efficiency caused by too low temperature, and at the same time avoid the hydrophilic finishing agent from being denatured due to too high temperature, thus losing its hydrophilic effect. The time is 40~60min.

[0022] The pre-baking temperature is 60~80 degrees Celsius. o C, the time is 40~60 minutes;

[0023] The baking temperature is 110~150℃ o C, time is 2~7 minutes.

[0024] This invention provides a hydrophilic PET ultrafine powder prepared by any of the above-described methods. The O / C value of the hydrophilic PET ultrafine powder is 0.38~0.47, while the O / C value of the raw material PET ultrafine powder is 0.32. The comparison shows that the oxygen content and surface hydrophilic hydroxyl groups of the modified PET ultrafine powder are increased.

[0025] The present invention also provides a method for preparing hydrophilic PET fibers, wherein the above-mentioned hydrophilic PET ultrafine powder is melt-blended and spun with PET chips to obtain hydrophilic PET fibers.

[0026] As a preferred technical solution:

[0027] In the above-described method for preparing hydrophilic PET fibers, the mass ratio of hydrophilic PET ultrafine powder to PET chips is 0.2~5:1.

[0028] In the method for preparing hydrophilic PET fibers as described above, the melt blending spinning temperature is 280~290°C. oC, the screw speed is 25~35Hz.

[0029] The method for preparing hydrophilic PET fiber described above results in a moisture regain of 0.55-1.24%, a moisture regain of 0.43-1.13% after 5 washes, and a volume resistivity of 10 Ω·cm. 10 ~5×10 13 Ω·cm, after 5 washes, the volume resistivity is 6×10 Ω·cm. 13 ~8×10 13 Ω·cm.

[0030] Beneficial effects:

[0031] (1) This invention proposes a new solution from the intermediate step (preparation of hydrophilic powder for spinning), taking into account both durability and feasibility of large-scale production; it abandons the traditional method of obtaining PET hydrophilic fibers, establishes a simple and easy method for preparing PET hydrophilic fibers, and develops hydrophilic PET ultrafine powder for direct use in fiber spinning.

[0032] (2) The present invention swells and activates the surface groups of PET ultrafine powder, and grafts the hydrophilic finishing agent onto the surface of the ultrafine powder with a crosslinking agent, which effectively increases the hydrophilic group content per unit mass of PET ultrafine powder, and at the same time improves the adhesion of the hydrophilic finishing agent to the PET substrate, ensuring the durability in subsequent melt spinning and in the use of finished fibers. Detailed Implementation

[0033] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0034] The PET chips used in the following examples and comparative examples are Polydi No. 5 PET chips.

[0035] The detection methods for relevant performance indicators in the examples and comparative examples are as follows:

[0036] Moisture regain: The moisture regain of the fiber was determined by oven drying method in accordance with GB / T 9995-1997;

[0037] Volume resistivity: Fiber resistivity was determined according to GB / T 14342-2015;

[0038] Soap washing: Refer to GB / T 3921-2008;

[0039] O / C value: The O / C value was measured using a TM3030 desktop scanning electron microscope (Hitachi High Technology Co., Ltd.), with an accelerating voltage of 15kV and an energy dispersive spectrometer of SwiftED3000.

[0040] Example 1

[0041] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0042] (1) Raw material preparation:

[0043] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0044] Alkaline solution: Sodium hydroxide solution, concentration 1 g / L;

[0045] The solution used for surface activation treatment is a mixture of choline chloride, oxalic acid and water (total concentration of choline chloride and oxalic acid is 10 g / L, and the molar ratio of choline chloride to oxalic acid is 0.5:1).

[0046] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100-160, viscosity 0.82 Pa·s, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid, and water (the natural polysaccharide is hyaluronic acid with a relative molecular weight of 80-120 W; the total concentration of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 20 g / L; and the molar ratio of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 1:3:1).

[0047] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of choline chloride, oxalic acid and water to obtain PET ultrafine powder with reactivity; wherein, the soaking temperature in alkaline solution is 60℃ and the time is 30min, and the soaking temperature in the mixture of choline chloride, oxalic acid and water is 40℃ and the time is 30min.

[0048] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 90℃ and the time is 40min; the pre-drying temperature is 60℃. o C, time is 60min; baking temperature is 110℃. o C, the time is 7 minutes;

[0049] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.38.

[0050] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 0.2:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 280°C. o C, the melting screw speed is 19.5 rpm;

[0051] The obtained hydrophilic PET fiber had a moisture regain of 0.67 ± 0.04% and a volume resistivity of 10 Ω·cm. 13 Ω·m, moisture regain after five soaping cycles was 0.43±0.04%, and volume resistivity after five soaping cycles was 6×10 Ω·m. 13 Ω·m.

[0052] Comparative Example 1

[0053] A method for preparing ultrafine powder is basically the same as the method for preparing hydrophilic ultrafine powder in Example 1. The only difference is that in step (1) of this comparative example, a mixture of choline chloride, oxalic acid and water is not prepared, and in step (2), the PET ultrafine powder is not soaked in the mixture of choline chloride, oxalic acid and water.

[0054] The final product is a PET ultrafine powder with an O / C value of 0.33.

[0055] A method for preparing hydrophilic PET fibers is basically the same as the method for preparing hydrophilic PET fibers in Example 1, except that the PET ultrafine powder obtained above is used instead of the hydrophilic PET ultrafine powder in Example 1.

[0056] The obtained PET fiber had a moisture regain of 0.53 ± 0.03% and a volume resistivity of 4 × 10⁻⁶. 13 Ω·m, moisture regain after five soaping cycles is 0.45±0.04%, and volume resistivity after five soaping cycles is 6×10 13 Ω·m.

[0057] Comparative Example 2

[0058] A method for preparing ultrafine powder is basically the same as the method for preparing hydrophilic ultrafine powder in Example 1, except that the same mass of deionized water is used in this comparative example to replace butanetetracarboxylic acid (butanetetracarboxylic acid in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water).

[0059] The final product is a PET ultrafine powder with an O / C value of 0.35.

[0060] A method for preparing hydrophilic PET fibers is basically the same as the method for preparing hydrophilic PET fibers in Example 1, except that the PET ultrafine powder obtained above is used instead of the hydrophilic PET ultrafine powder in Example 1.

[0061] The obtained PET fiber had a moisture regain of 0.52 ± 0.03% and a volume resistivity of 7 × 10⁻⁶. 13 Ω·m, moisture regain after five soaping cycles was 0.43±0.02%, and volume resistivity after five soaping cycles was 8×10 Ω·m. 13 Ω·m.

[0062] By comprehensively comparing the data of Example 1, Comparative Example 1, and Comparative Example 2, it was found that the PET powder in Comparative Example 1, which was not treated with choline chloride, oxalic acid, and the mixed solution, had fewer surface reactive sites, resulting in a lower grafting rate during the subsequent hydrophilic finishing agent grafting process. The hydrophilic agent, which was only bound by intermolecular interactions but not covalently, was also washed away during the cleaning process, leading to a low content of hydrophilic groups in the final PET powder and poor hydrophilicity of the spun yarn. In Comparative Example 2, only the PET powder was activated but no hydrophilic agent was used for the subsequent crosslinking reaction. Although the surface active groups were slightly increased, the poor thermal stability of the groups made them easy to be consumed in the subsequent cleaning and melt spinning, resulting in a low content of hydrophilic groups in the final product.

[0063] In summary, the surface activation of PET powder and the subsequent hydrophilic agent grafting reaction are the two essential steps in obtaining the target product in this invention.

[0064] Example 2

[0065] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0066] (1) Raw material preparation:

[0067] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0068] Alkaline solution: Sodium hydroxide solution, concentration 30 g / L;

[0069] The solution used for surface activation treatment is a mixture of choline chloride, oxalic acid, and water (the total concentration of choline chloride and oxalic acid is 50 g / L, and the molar ratio of choline chloride to oxalic acid is 0.5:1).

[0070] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100-160, viscosity 0.82 Pa·s, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid, and water (the natural polysaccharide is hyaluronic acid with a relative molecular weight of 80-120 W; the total concentration of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 20 g / L; and the molar ratio of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 1:3:1).

[0071] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of choline chloride, oxalic acid and water to obtain PET ultrafine powder with reactivity; wherein, the soaking temperature in alkaline solution is 70℃ and the time is 60min, and the soaking temperature in the mixture of choline chloride, oxalic acid and water is 40℃ and the time is 50min.

[0072] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 90℃ and the time is 50min; the pre-drying temperature is 80℃. o C, time is 40 min; baking temperature is 120 o C, time is 6 minutes;

[0073] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.4.

[0074] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 1:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 280°C. o C, the melting screw speed is 20.5 rpm;

[0075] The obtained hydrophilic PET fiber had a moisture regain of 0.73±0.04% and a volume resistivity of 5×10⁻⁶. 12 Ω·m, moisture regain after five soaping cycles is 0.55±0.03%, and volume resistivity after five soaping cycles is 8×10 12 Ω·m.

[0076] Example 3

[0077] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0078] (1) Raw material preparation:

[0079] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0080] Alkaline solution: Sodium hydroxide solution, concentration 30 g / L;

[0081] The solution used for surface activation treatment is a mixture of choline chloride, oxalic acid, and water (the total concentration of choline chloride and oxalic acid is 100 g / L, and the molar ratio of choline chloride to oxalic acid is 1:1).

[0082] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100-160, viscosity 0.82 Pa·s, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid, and water (the natural polysaccharide is hyaluronic acid with a relative molecular weight of 80-120 W; the total concentration of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 30 g / L; and the molar ratio of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 1:5:5).

[0083] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of choline chloride, oxalic acid and water to obtain PET ultrafine powder with reactivity; wherein, the soaking temperature in alkaline solution is 85℃ and the time is 60min, and the soaking temperature in the mixture of choline chloride, oxalic acid and water is 60℃ and the time is 70min.

[0084] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 100℃ and the time is 50min; the pre-drying temperature is 80℃. o C, time is 60min; baking temperature is 135℃ o C, time is 5 minutes;

[0085] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.42.

[0086] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 3:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 280°C. o C, The melting screw speed is 20 rpm;

[0087] The obtained hydrophilic PET fiber had a moisture regain of 0.88±0.02% and a volume resistivity of 7×10⁻⁶. 11 Ω·m, moisture regain after five soaping cycles is 0.75±0.05%, and volume resistivity after five soaping cycles is 10 Ω·m. 12 Ω·m.

[0088] Example 4

[0089] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0090] (1) Raw material preparation:

[0091] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0092] Alkaline solution: Sodium hydroxide solution, concentration 30 g / L;

[0093] The solution used for surface activation treatment is a mixture of choline chloride, oxalic acid, and water (the total concentration of choline chloride and oxalic acid is 50 g / L, and the molar ratio of choline chloride to oxalic acid is 0.5:1).

[0094] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100-160, viscosity 0.82 Pa·s, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid, and water (the natural polysaccharide is hyaluronic acid with a relative molecular weight of 80-120 W; the total concentration of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 30 g / L; and the molar ratio of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 1:5:8).

[0095] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of choline chloride, oxalic acid and water to obtain PET ultrafine powder with reactivity; wherein, the soaking temperature in alkaline solution is 95℃ and the time is 90min, and the soaking temperature in the mixture of choline chloride, oxalic acid and water is 80℃ and the time is 90min.

[0096] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 100℃ and the time is 60min; the pre-drying temperature is 80℃. o C, time is 40 minutes; baking temperature is 150°C.o C, time is 2 minutes;

[0097] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.47.

[0098] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 5:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 290°C. o C, The melting screw speed is 20 rpm;

[0099] The resulting hydrophilic PET fiber had a moisture regain of 1.24 ± 0.04% and a volume resistivity of 10 Ω·cm. 10 Ω·m, moisture regain after five soaping cycles was 1.13±0.03%, and volume resistivity after five soaping cycles was 3×10 Ω·m. 10 Ω·m.

[0100] Example 5

[0101] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0102] (1) Raw material preparation:

[0103] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0104] Alkaline solution: potassium hydroxide solution, concentration 1 g / L;

[0105] The solution used for surface activation treatment is a mixture of potassium carbonate, ethylene glycol, and water (the total concentration of potassium carbonate and ethylene glycol is 50 g / L, and the molar ratio of potassium carbonate to ethylene glycol is 1:4).

[0106] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100-160, viscosity 0.82 Pa·s, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid, and water (the natural polysaccharide is hyaluronic acid with a relative molecular weight of 80-120 W; the total concentration of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 20 g / L; and the molar ratio of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 1:3:1).

[0107] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of potassium carbonate, ethylene glycol and water to obtain reactive PET ultrafine powder; wherein, the soaking temperature in alkaline solution is 60℃ and the soaking time is 30min, and the soaking temperature in the mixture of potassium carbonate, ethylene glycol and water is 60℃ and the soaking time is 60min.

[0108] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 90℃ and the time is 40min; the pre-drying temperature is 60℃. o C, time is 60min; baking temperature is 110℃. o C, the time is 7 minutes;

[0109] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.38.

[0110] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 0.2:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 280°C. o C, the melting screw speed is 19.5 rpm;

[0111] The obtained hydrophilic PET fiber had a moisture regain of 0.55±0.04% and a volume resistivity of 5×10⁻⁶. 13 Ω·m, moisture regain after five soaping cycles was 0.41±0.04%, and volume resistivity after five soaping cycles was 8×10 Ω·m. 13 Ω·m.

[0112] Example 6

[0113] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0114] (1) Raw material preparation:

[0115] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0116] Alkaline solution: potassium hydroxide solution, concentration 30 g / L;

[0117] The solution used for surface activation treatment is a mixture of potassium carbonate, ethylene glycol, and water (the total concentration of potassium carbonate and ethylene glycol is 70 g / L, and the molar ratio of potassium carbonate to ethylene glycol is 1:5).

[0118] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100~160, viscosity 0.82 Pa·S, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid and water (the natural polysaccharide is water-soluble chitosan with a relative molecular weight of 100W, the total concentration of polyethylene glycol, natural polysaccharide and butanetetracarboxylic acid is 30 g / L, and the molar ratio of polyethylene glycol, natural polysaccharide and butanetetracarboxylic acid is 1:3:1).

[0119] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of potassium carbonate, ethylene glycol and water to obtain reactive PET ultrafine powder; wherein, the soaking temperature in alkaline solution is 70℃ and the time is 60min, and the soaking temperature in the mixture of potassium carbonate, ethylene glycol and water is 70℃ and the time is 80min.

[0120] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 90℃ and the time is 50min; the pre-drying temperature is 80℃. o C, time is 40 min; baking temperature is 120 o C, time is 6 minutes;

[0121] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.39.

[0122] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 1:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 280°C. o C, the melting screw speed is 20.5 rpm;

[0123] The obtained hydrophilic PET fiber had a moisture regain of 0.62 ± 0.04% and a volume resistivity of 5 × 10⁻⁶. 12 Ω·m, moisture regain after five soaping cycles was 0.47±0.03%, and volume resistivity after five soaping cycles was 9×10 Ω·m. 12 Ω·m.

[0124] Example 7

[0125] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0126] (1) Raw material preparation:

[0127] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0128] Alkaline solution: potassium hydroxide solution, concentration 50 g / L;

[0129] The solution used for surface activation treatment is a mixture of potassium carbonate, ethylene glycol, and water (the total concentration of potassium carbonate and ethylene glycol is 100 g / L, and the molar ratio of potassium carbonate to ethylene glycol is 1:6).

[0130] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100~160, viscosity 0.82 Pa·S, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid and water (the natural polysaccharide is water-soluble chitosan with a relative molecular weight of 100W, the total concentration of polyethylene glycol, natural polysaccharide and butanetetracarboxylic acid is 40 g / L, and the molar ratio of polyethylene glycol, natural polysaccharide and butanetetracarboxylic acid is 1:5:5).

[0131] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of potassium carbonate, ethylene glycol and water to obtain reactive PET ultrafine powder; wherein, the soaking temperature in alkaline solution is 85℃ and the time is 60min, and the soaking temperature in the mixture of potassium carbonate, ethylene glycol and water is 85℃ and the time is 100min.

[0132] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 100℃ and the time is 50min; the pre-drying temperature is 80℃. o C, time is 60min; baking temperature is 135℃ o C, time is 5 minutes;

[0133] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.41.

[0134] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 3:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 280°C. oC, The melting screw speed is 35Hz;

[0135] The obtained hydrophilic PET fiber had a moisture regain of 0.78 ± 0.02% and a volume resistivity of 2 × 10⁻⁶. 12 Ω·m, moisture regain after five soaping cycles was 0.59±0.05%, and volume resistivity after five soaping cycles was 5×10⁻⁶. 12 Ω·m.

[0136] Example 8

[0137] A method for preparing hydrophilic PET ultrafine powder, the specific steps of which are as follows:

[0138] (1) Raw material preparation:

[0139] PET ultrafine powder: Dongguan Tesulang 1000 mesh PET powder (https: / / detail.1688.com / offer / 601133018086.html?spm=a261b.2187593.0.0.3a08773ecGmLwN);

[0140] Alkaline solution: potassium hydroxide solution, concentration 50 g / L;

[0141] The solution used for surface activation treatment is a mixture of potassium carbonate, ethylene glycol, and water (the total concentration of potassium carbonate and ethylene glycol is 150 g / L, and the molar ratio of potassium carbonate to ethylene glycol is 1:8).

[0142] The solution used for grafting treatment is a mixture of polyethylene glycol (degree of polymerization 100-160, viscosity 0.82 Pa·S, crystallinity 52%), natural polysaccharide, butanetetracarboxylic acid, and water (the natural polysaccharide is water-soluble chitosan with a relative molecular weight of 100W; the total concentration of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 60 g / L; and the molar ratio of polyethylene glycol, natural polysaccharide, and butanetetracarboxylic acid is 1:5:8).

[0143] (2) First, PET ultrafine powder is soaked in alkaline solution, and then PET ultrafine powder is soaked in a mixture of potassium carbonate, ethylene glycol and water to obtain reactive PET ultrafine powder; wherein, the soaking temperature in alkaline solution is 95℃ and the time is 90min, and the soaking temperature in the mixture of potassium carbonate, ethylene glycol and water is 100℃ and the time is 120min.

[0144] (3) The reactive PET ultrafine powder is impregnated and shaken in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, then pre-dried, baked, and purified by centrifugation to obtain hydrophilic PET ultrafine powder; wherein the impregnation and shaking temperature in the mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 100℃ and the time is 60min; the pre-drying temperature is 80℃. o C, time is 40 minutes; baking temperature is 150°C. o C, time is 2 minutes;

[0145] The final product is a hydrophilic PET ultrafine powder with an O / C value of 0.43.

[0146] A method for preparing hydrophilic PET fibers involves melt-blending and spinning the aforementioned hydrophilic PET ultrafine powder with PET chips at a mass ratio of 5:1 to obtain hydrophilic PET fibers; wherein the melt-blending and spinning temperature is 290°C. o C, The melting screw speed is 35Hz;

[0147] The obtained hydrophilic PET fiber had a moisture regain of 0.90±0.04% and a volume resistivity of 9×10⁻⁶. 11 Ω·m, moisture regain after five soaping cycles was 0.81±0.03%, and volume resistivity after five soaping cycles was 5×10 Ω·m. 12 Ω·m.

Claims

1. A method for preparing hydrophilic PET ultrafine powder, characterized in that, First, PET ultrafine powder is swollen and surface group activated to obtain reactive PET ultrafine powder. Then, a hydrophilic finishing agent is covalently grafted onto the surface of the reactive PET ultrafine powder using a crosslinking agent to obtain hydrophilic PET ultrafine powder. The average particle size of the PET ultrafine powder is 5~10μm. The PET ultrafine powder swelling and surface group activation treatment refers to: first soaking the PET ultrafine powder in an alkaline solution, and then soaking the PET ultrafine powder in a mixture of choline chloride, oxalic acid and water or a mixture of potassium carbonate, ethylene glycol and water.

2. The method for preparing hydrophilic PET ultrafine powder according to claim 1, characterized in that, The alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution; the concentration of the alkaline solution is 1~50g / L; the soaking temperature in the alkaline solution is 60~95℃, and the soaking time is 30~90min; In a mixture of choline chloride, oxalic acid and water, the total concentration of choline chloride and oxalic acid is 10~100g / L, and the molar ratio of choline chloride to oxalic acid is 0.5~2:

1. In a mixture of potassium carbonate, ethylene glycol and water, the total concentration of potassium carbonate and ethylene glycol is 50~150 g / L, and the molar ratio of potassium carbonate to ethylene glycol is 1:4~8. The temperature for soaking in a mixture of choline chloride, oxalic acid and water is 40-80℃, and the time is 30-90 minutes. The temperature for immersion in a mixture of potassium carbonate, ethylene glycol, and water is 60-100℃, and the time is 60-120 minutes.

3. The method for preparing hydrophilic PET ultrafine powder according to claim 1, characterized in that, The process of covalently grafting a hydrophilic finishing agent onto the surface of reactive PET ultrafine powder via a crosslinking agent refers to: immersing the reactive PET ultrafine powder in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid, and water, followed by shaking, and then pre-drying and baking sequentially. The natural polysaccharide is either hyaluronic acid or water-soluble chitosan.

4. The method for preparing hydrophilic PET ultrafine powder according to claim 3, characterized in that, In a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water, the total concentration of polyethylene glycol, natural polysaccharide and butanetetracarboxylic acid is 20~60 g / L, and the molar ratio of polyethylene glycol, natural polysaccharide and butanetetracarboxylic acid is 1:2~5:1~8. The temperature for immersion and shaking in a mixture of polyethylene glycol, natural polysaccharide, butanetetracarboxylic acid and water is 90~100℃ and the time is 40~60min. The pre-baking temperature is 60~80 degrees Celsius. o C, the time is 40~60 minutes; The baking temperature is 110~150℃ o C, time is 2~7 minutes.

5. The hydrophilic PET ultrafine powder prepared by the method for preparing hydrophilic PET ultrafine powder according to any one of claims 1 to 4, characterized in that, The O / C value of hydrophilic PET ultrafine powder is 0.38~0.

47.

6. A method for preparing hydrophilic PET fibers, characterized in that, Hydrophilic PET fibers are obtained by melt-blending and spinning the hydrophilic PET ultrafine powder as described in claim 5 with PET chips.

7. The method for preparing hydrophilic PET fiber according to claim 6, characterized in that, The mass ratio of hydrophilic PET ultrafine powder to PET chips is 0.2~5:1.