Preparation method of bio-based PTT ion adsorption fiber and PTT fiber

Abstract

The invention discloses a bio-based PTT ion adsorption fiber preparation method and PTT fibers.The bio-based PTT ion adsorption fiber preparation method comprises the steps that bio-based PTT fibers are pretreated through a NaOH solution, chitosan-glycidyl methacrylate copolymer is dissolved in an acetic acid solution, deionized water, hydroquinone and a catalyst are added to prepare a modified solution, and the modified solution is subjected to ultrasonic treatment; and immersing the pretreated bio-based PTT fiber into the modified solution, reacting under a nitrogen condition, cleaning with a NaOH solution for a set time, washing with deionized water, and drying. According to the technical scheme provided by the embodiment of the invention, the bio-based PTT fiber is selected as a functional base material, so that compared with a traditional petroleum-based adsorption material, the bio-based PTT fiber has an excellent biodegradable characteristic, effectively overcomes the risk of secondary pollution, and conforms to the concept of green sustainable development. Meanwhile, the introduced chitosan component is rich in high-density amino functional groups, so that powerful chelation sites are provided for heavy metal ions, and the effective adsorbability and selective adsorbability of the modified fiber are ensured.

Description

TECHNICAL FIELD

[0001] The present application generally relates to the field of functional fibers, and in particular to a method for preparing a bio-based PTT ion-adsorbing fiber and a PTT fiber. BACKGROUND

[0002] Traditional ion-adsorbing materials such as activated carbon and ion exchange resin have been industrialized, but their single function, high energy consumption for regeneration and secondary pollution risk have made it difficult to meet the demand for green development. Under this background, bio-based polymer-based functional fibers have become a research frontier in the field of adsorbent materials due to their renewable and degradable properties.

[0003] Bio-based polytrimethylene terephthalate (PTT) is a polyester material synthesized from 1,3-propanediol (PDO) produced by biomass fermentation. Due to its unique chemical structure and physical properties, it has received widespread attention in the field of ion-adsorbing fibers. First, the unique Z-shaped helical conformation of its molecular chain endows the fiber with excellent elasticity and resilience, ensuring the structural stability during dynamic adsorption. Second, the presence of active groups such as terminal carboxyl and terminal hydroxyl groups in the molecular chain of PTT allows for the introduction of specific adsorption sites through copolymerization or surface grafting, enhancing the targeted adsorption of heavy metal ions. In addition, PTT fibers are biodegradable and can be broken down by microorganisms after disposal, avoiding environmental pollution. The regeneration process can be achieved through acid or base desorption under mild conditions, ensuring stable recycling performance and significantly reducing material consumption and processing costs, making it a potential application in the field of adsorbent materials.

[0004] In the prior art, although there have been reports of modifying PTT through copolymerization or grafting, most of them focus on antibacterial and flame-retardant properties, and there is no systematic research on adsorption function. SUMMARY

[0005] In view of the above-mentioned defects or shortcomings in the prior art, it is desirable to provide a bio-based PTT ion-adsorbing fiber preparation method and a PTT fiber.

[0006] In a first aspect, a bio-based PTT ion-adsorbing fiber preparation method is provided, the method comprising: pretreating the bio-based PTT fiber with a NaOH solution, dissolving chitosan-glycidyl methacrylate copolymer in a 1% acetic acid water mixture solution, adjusting the solution to neutral, adding 0.1wt% hydroquinone, and adding a catalyst benzoyl peroxide to prepare a modified solution, immersing the pretreated bio-based PTT fiber in the modified solution and reacting under nitrogen conditions, taking out the reacted bio-based PTT fiber, and washing it with a NaOH solution for a set time, The fibers were then washed with deionized water and dried to obtain bio-based PTT ion-adsorption fibers.

[0007] As a feasible approach, pretreatment of bio-based PTT fibers specifically includes the following steps: The bio-based PTT fiber was immersed in NaOH solution and treated at 90±5℃ for 1 hour. The treated bio-based PTT fibers were placed in 3% acetic acid by volume for a period of time, then washed with deionized water and dried.

[0008] As an alternative approach, the concentration of the NaOH solution in the pretreatment step is 0.5-2 mol / L.

[0009] As an feasible approach, the method for preparing the chitosan-glycidyl methacrylate copolymer includes the following steps: Chitosan was dissolved in a 0.4 mol / L acetic acid solution. 0.05 mol / L KOH was added at 5% (by volume) relative to the total reaction mixture. Purified glycidyl methacrylate was slowly added to the reaction flask containing chitosan at a molar ratio of chitosan / glycidyl methacrylate = 1 / 3. The pH of the solution was adjusted to acidic. The reaction was carried out under nitrogen atmosphere at 60°C for 2 hours. The final product was cooled in an ice bath for 15 minutes, precipitated by acetonitrile, washed with tetrahydrofuran, and dried under vacuum at 50°C for 24 hours to obtain the chitosan-glycidyl methacrylate copolymer.

[0010] As an example, the benzoyl peroxide content is 0.4%-0.7wt%.

[0011] As an example, the bath ratio of the pretreated bio-based PTT fiber to the modified solution is 1:(10-40).

[0012] As an example, the reaction temperature under nitrogen is 50-90°C and the reaction time is 3-5 hours.

[0013] Secondly, a PTT fiber is provided, which is prepared using the above-mentioned method for preparing bio-based PTT ion adsorption fibers.

[0014] According to the technical solution provided in the embodiments of this application, by selecting bio-based PTT fiber as the functionalized substrate, it exhibits excellent biodegradability compared to traditional petroleum-based adsorbent materials, effectively overcoming the risk of secondary pollution and conforming to the concept of green and sustainable development. Simultaneously, the introduced chitosan component is rich in high-density amino functional groups, providing strong chelation sites for heavy metal ions, ensuring the effective adsorption and selective adsorption of the modified fiber. Attached Figure Description

[0015] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart of the preparation method of bio-based PTT ion adsorption fiber provided in this embodiment. Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] Please refer to Figure 1 This embodiment provides a method for preparing bio-based PTT ion adsorption fibers, including the following steps: Bio-based PTT fibers were pretreated with NaOH solution. Chitosan-glycidyl methacrylate copolymer was dissolved in a 1% (v / v) acetic acid-water mixture, and the solution was adjusted to neutral. 0.1 wt% hydroquinone was added, along with the catalyst benzoyl peroxide, to prepare a modified solution. The pretreated bio-based PTT fibers were immersed in the modified solution and reacted under nitrogen atmosphere. The reacted bio-based PTT fibers were then removed and washed with NaOH solution for a set time. The fibers were then washed with deionized water and dried to obtain bio-based PTT ion-adsorption fibers.

[0019] In this embodiment, bio-based PTT fiber is selected as the functionalized substrate. Compared with traditional petroleum-based adsorbents, it has excellent biodegradability, effectively overcoming the risk of secondary pollution and conforming to the concept of green and sustainable development. At the same time, the introduced chitosan component is rich in high-density amino functional groups, providing strong chelation sites for heavy metal ions, ensuring the effective adsorption and selective adsorption of the modified fiber.

[0020] In the preparation process, the bio-based PTT fibers are first pretreated with NaOH solution at a concentration of 0.5-2 mol / L. The pretreatment steps include: The bio-based PTT fiber was immersed in NaOH solution and treated at 90±5℃ for 1 hour. The treated bio-based PTT fibers were placed in 3% acetic acid by volume for a period of time, then washed with deionized water and dried.

[0021] The Z-shaped helical structure of the bio-based PTT fiber in this embodiment endows it with ultra-high resilience, with a breaking elongation greater than 30% and a surface carboxyl group density as high as 0.8 mol / g, which can provide active sites for subsequent grafting steps.

[0022] The preparation of chitosan-glycidyl methacrylate copolymer is then carried out, including the following steps: Chitosan (CS) was dissolved in a 0.4 mol / L acetic acid solution. 0.05 mol / L KOH was added at 5% (by volume) relative to the total reaction mixture. Purified glycidyl methacrylate (GMA) was slowly added to the reaction flask containing chitosan at a molar ratio of chitosan / glycidyl methacrylate = 1 / 3. The pH of the solution was adjusted to acidic. The reaction was carried out under nitrogen atmosphere at 60°C for 2 hours. The final product was cooled in an ice bath for 15 minutes, precipitated by acetonitrile, washed with tetrahydrofuran, and dried under vacuum at 50°C for 24 hours to obtain the chitosan-glycidyl methacrylate copolymer.

[0023] The prepared chitosan-glycidyl methacrylate copolymer was grafted onto PTT fibers, making the modified PTT fibers rich in amino functional groups. This resulted in highly efficient adsorption capacity for heavy metal ions, especially copper and lead ions, making them very suitable for use in the treatment of industrial wastewater containing heavy metals and leachate from electronic waste.

[0024] In this process, the pH value of the solution is adjusted to make it acidic. The preferred pH value is 3.8, and a fluctuation of 0.5 is also within the normal range.

[0025] Subsequently, a grafting process of bio-based PTT fibers was carried out. The chitosan-glycidyl methacrylate copolymer prepared above was dissolved in acetic acid solution, and deionized water was added to prepare an acetic acid-water mixed solution, wherein the volume ratio of acetic acid and water was 1%. The pH value of the solution was adjusted to neutral, and 0.1 wt% hydroquinone (HQ) was added to inhibit the homopolymerization side reaction of glycidyl methacrylate. Then, a catalyst was added to form a modified solution.

[0026] Optionally, the catalyst is benzoyl peroxide (BPO) at 0.4-0.7 wt%.

[0027] The pretreated bio-based PTT fibers were then immersed in the modified solution at a bath ratio of 1:(10-40) and the reaction was carried out under nitrogen conditions. The reaction temperature was 50-90 °C and the reaction time was 3-5 hours to carry out the grafting reaction of the bio-based PTT fibers.

[0028] The fiber was then washed with a 1 mol / L NaOH solution for at least 2 hours, followed by washing with deionized water and vacuum drying at 50°C to obtain the modified fiber, which is the bio-based PTT ion adsorption fiber designed in this disclosure.

[0029] The fibers prepared in the above embodiments achieved controllable grafting through precise processing, bath ratio, and reaction temperature, and the grafted PTT fibers exhibited high removal rates of copper and lead ions. The fiber preparation mechanism diagram provided in this embodiment is shown below.

[0030] This application also provides a bio-based PTT ion adsorption fiber, which is prepared using the preparation method described above.

[0031] The following are several sets of embodiments and comparative examples: Example 1: S1. Immerse 2.0g of bio-based PTT fiber in 100mL of 1.0M NaOH solution and treat at 90℃ for 1 hour. After treatment, incubate the PTT fiber in 3% acetic acid at room temperature overnight, then wash with deionized water and dry at 50℃. S2. Dissolve 1.8 g of chitosan-glycidyl methacrylate copolymer in 60 mL of a 1% acetic acid / water mixture, adjust the solution to neutral, and add 0.004 g of HQ and 0.02 g of BPO. S3. Immerse the pretreated PTT fibers in the solution prepared in S2 at a bath ratio of 1:30, react at 70°C for 4 hours under nitrogen protection, ultrasonically clean with 1.0 M NaOH for 10 minutes, wash with deionized water, and vacuum dry at 50°C.

[0032] Example 2: S1. Immerse 2.0g of bio-based PTT fiber in 100mL of 2.0M NaOH solution and treat at 90℃ for 1 hour. After treatment, incubate the PTT fiber in 3% acetic acid at room temperature overnight, then wash with deionized water and dry at 50℃. S2. Dissolve 2.0 g of chitosan-glycidyl methacrylate copolymer in 50 mL of a 1% (v / v) acetic acid / water mixed solution, adjust the solution to neutral, and add 0.004 g of HQ and 0.02 g of BPO; S3. Immerse the pretreated PTT fibers in the solution prepared in S2 at a bath ratio of 1:25, react at 90 °C for 3 hours under nitrogen protection, ultrasonically clean with 1.0 M NaOH for 10 minutes, wash with deionized water, and vacuum dry at 50 °C.

[0033] Example 3: S1. Immerse 2.0g of bio-based PTT fiber in 100mL of 0.5M NaOH solution and treat at 90℃ for 1 hour. After treatment, incubate the PTT fiber in 3% acetic acid at room temperature overnight, then wash with deionized water and dry at 50℃. S2. Dissolve 1.6 g of chitosan-glycidyl methacrylate copolymer in 80 mL of a 1% (v / v) acetic acid / water mixed solution, adjust the solution to neutral, and add 0.004 g of HQ and 0.02 g of BPO; S3. Immerse the pretreated PTT fibers in the solution prepared in S2 at a bath ratio of 1:40, react at 70 °C for 5 hours under nitrogen protection, ultrasonically clean with 1.0 M NaOH for 10 minutes, wash with deionized water, and vacuum dry at 50 °C.

[0034] Comparative Example 1: 0.05 g of unmodified bio-based PTT fiber was placed in a Cu(II) and Pb(II) ion solution with pH=5 and a concentration of 150 mg / L, and the removal rate was calculated.

[0035] Comparative Example 2: S1. Immerse 2.0 g of bio-based PTT fiber in 100 mL of 1 M NaOH solution and treat at 90 °C for 1 hour. After treatment, incubate the PTT fiber in 3% acetic acid at room temperature overnight, then wash with deionized water and dry at 50 °C. Take 0.05 g of alkali-treated, ungrafted bio-based PTT fiber and place it in a Cu(II) and Pb(II) ion solution with pH=5 and a concentration of 150 mg / L, and calculate the removal rate.

[0036] The grafting rate of the fibers prepared in the calculation examples was determined. To explore the application of the modified bio-based PTT fibers prepared in this example in the field of ion adsorption, the specific adsorption process is as follows: 0.05 g of modified bio-based PTT fibers were placed in a Cu(II) and Pb(II) ion solution with pH=5 and a concentration of 150 mg / L, and the removal rate was calculated. The experimental results are shown in the table below.

[0037] Comparing Examples 1-3 and Comparative Examples 1-2, and referring to Table 1, it can be seen that: the test results of Comparative Example 1 show that the density of active adsorption sites on the surface of the unmodified original cellulose substrate is insufficient, resulting in an adsorption efficiency of only 9.43% and 4.40% for Pb(II) and Cu(II), respectively; although Comparative Example 2, which has undergone alkali pretreatment, can induce the generation of some active functional groups (such as carboxylate groups) on the fiber surface, increasing the adsorption efficiency of heavy metal ions to 15.36% (Pb(II)) and 10.11% (Cu(II)), its adsorption capacity is still significantly lower than that of the chemically grafted modified fiber material. The above experimental results fully verify that chitosan-glycidyl methacrylate copolymer graft modification is a key technical path for constructing a highly efficient heavy metal adsorption interface, and the specific adsorption units introduced through covalent bonding play a decisive role in improving the adsorption performance of the material.

[0038] Furthermore, as shown in Examples 1-3 and Table 1, by adjusting the NaOH concentration (0.5~2.0 M), the amount of chitosan-glycidyl methacrylate copolymer (1.6~2.0 g / 2g fiber), the bath ratio (1:25~1:40), and the reaction temperature (70~90℃), the grafting process can be precisely controlled. The grafting rate first increases and then decreases with the increase of monomer and temperature, indicating that there is an optimal process window.

[0039] As shown in Examples 1-3, the removal rates of Pb²⁺ and Cu²⁺ by the modified fibers significantly increased with increasing grafting rate. Example 2 achieved removal rates of 97.45% and 94.62% for Pb(II) and Cu(II), respectively, significantly higher than Examples 1 and 3. This is attributed to the abundant amino (-NH₂) and hydroxyl (-OH) groups in the chitosan-glycidyl methacrylate copolymer molecular chain, which can efficiently capture heavy metal ions through chelation. A higher grafting rate results in a greater density of active sites on the fiber surface, thus increasing the adsorption capacity. Furthermore, the modified fibers exhibited high selectivity for both ions (removal rate >90%) at pH=5, making them suitable for acidic wastewater treatment and demonstrating their potential application value as an environmentally friendly ion adsorption material.

[0040] It should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used above to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention; the directional terms "inner" and "outer" refer to the inside or outside relative to the outline of each component itself. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0041] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for preparing bio-based PTT ion adsorption fibers, characterized in that, The method includes: Bio-based PTT fibers were pretreated with NaOH solution. Chitosan-glycidyl methacrylate copolymer was dissolved in a 1% (v / v) acetic acid-water mixture, and the solution was adjusted to neutral. 0.1 wt% hydroquinone was added, along with the catalyst benzoyl peroxide, to prepare a modified solution. The pretreated bio-based PTT fibers were immersed in the modified solution and reacted under nitrogen atmosphere. The reacted bio-based PTT fibers were then removed and washed with NaOH solution for a set time. The fibers were then washed with deionized water and dried to obtain bio-based PTT ion-adsorption fibers.

2. The method for preparing bio-based PTT ion adsorption fiber according to claim 1, characterized in that, The pretreatment of bio-based PTT fibers specifically includes the following steps: The bio-based PTT fiber was immersed in NaOH solution and treated at 90±5℃ for 1 hour. The treated bio-based PTT fibers were placed in 3% acetic acid by volume for a period of time, then washed with deionized water and dried.

3. The method for preparing bio-based PTT ion adsorption fiber according to claim 1, characterized in that, The concentration of NaOH solution in the pretreatment step is 0.5-2 mol / L.

4. The method for preparing bio-based PTT ion adsorption fiber according to claim 1, characterized in that, The method for preparing the chitosan-glycidyl methacrylate copolymer includes the following steps: Chitosan was dissolved in a 0.4 mol / L acetic acid solution. 0.05 mol / L KOH was added at 5% (by volume) relative to the total reaction mixture. Purified glycidyl methacrylate was slowly added to the reaction flask containing chitosan at a molar ratio of chitosan / glycidyl methacrylate = 1 / 3. The pH of the solution was adjusted to acidic. The reaction was carried out under nitrogen atmosphere at 60°C for 2 hours. The final product was cooled in an ice bath for 15 minutes, precipitated by acetonitrile, washed with tetrahydrofuran, and dried under vacuum at 50°C for 24 hours to obtain the chitosan-glycidyl methacrylate copolymer.

5. The method for preparing bio-based PTT ion adsorption fiber according to claim 1, characterized in that, The benzoyl peroxide is 0.4-0.7 wt%.

6. The method for preparing bio-based PTT ion adsorption fiber according to claim 1, characterized in that, The bath ratio of the pretreated bio-based PTT fiber to the modified solution is 1:(10-40).

7. The method for preparing bio-based PTT ion adsorption fiber according to claim 1, characterized in that, The reaction temperature under nitrogen atmosphere is 50-90℃, and the reaction time is 3-5 hours.

8. A PTT fiber, characterized in that, It is prepared using the bio-based PTT ion adsorption fiber preparation method according to any one of claims 1-7.

Images