A method for preparing polyester-based composite hydrophilic material

Abstract

The present invention discloses a method for preparing a polyester-based composite hydrophilic material. The method comprises fibrillating small pieces of waste polyester fabric, then surface-amiding the fibers with a 5-30 wt% aqueous solution of diethylenetriamine to obtain aminated polyester fibers. The small pieces of waste polyester fabric are then aminolyzed with diethylenetriamine in the presence of a zinc acetate catalyst to obtain a polyester aminolysis solution, which is diluted and reacted with ethylene glycol glycidyl ether to prepare a crosslinking solution. Finally, the aminated polyester fibers are immersed in the crosslinking solution to obtain the polyester-based composite hydrophilic material. The polyester-based composite hydrophilic material prepared by the method has a static water contact angle of no more than 30°, exhibits excellent hydrophilic properties, and can be used as an adsorbent material in water treatment, particularly in the treatment of dye wastewater.

Description

Technical Field

[0001] The invention belongs to the technical field of adsorption material preparation, and relates to a method for preparing a hydrophilic adsorption material based on polyester fiber degradation. Background Art

[0002] Polyester fiber, a common polymer material, is widely used in the textile industry due to its excellent physical and chemical properties. However, this also leads to the generation of a large amount of polyester fabric waste. As the world's largest producer and consumer of textile fiber, China produces a particularly significant amount of waste polyester fabric. According to statistics from the China Chemical Fiber Industry Association, the domestic stockpile of waste textiles is nearly 400 million tons, of which polyester fiber accounts for a large proportion.

[0003] Recycling technologies for waste polyester fabrics primarily include physical, chemical, and physicochemical methods. While some progress has been made in these various approaches, the overall recycling rate remains low. Actively exploring recycling technologies for waste polyester fabrics is imperative.

[0004] To ensure the "green" and sustainable use of petrochemical resources, a growing number of researchers are working to convert and reuse waste polymers through chemical degradation, such as depolymerizing polyester fabrics into useful low-molecular-weight intermediates. However, recycling highly polymerized polyester fibers and further preparing them into more functional materials, particularly hydrophilic materials, remains a challenge.

[0005] Hydrophilic materials have excellent water dispersibility and wettability, forming hydrogen bonds with water molecules and acting as adsorbents, effectively adsorbing pollutants in water. Due to their excellent adsorption properties, hydrophilic adsorbents have found widespread application in water treatment and environmental governance. In water treatment, hydrophilic adsorbents can effectively remove harmful substances such as heavy metal ions and organic pollutants from water, improving water quality. In environmental governance, hydrophilic adsorbents can be used in soil remediation and air purification, contributing positively to improving environmental quality.

[0006] The use of waste polyester fibers to prepare hydrophilic materials can not only provide a recycling method for waste polyester, but also solve the problem of resource waste to a certain extent, which has huge social and economic benefits. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for preparing a polyester-based composite hydrophilic material, so as to utilize waste polyester fabrics to prepare a composite hydrophilic material with excellent hydrophilic properties for use as an adsorption material.

[0008] Based on the above invention objectives, the present invention first provides a method for preparing a polyester-based composite hydrophilic material, which specifically includes:

[0009] S1, shearing small pieces of waste polyester fabric in a pulverizer to partially fibrillate the fibers to obtain fibrillated polyester fibers;

[0010] S2, performing surface amination treatment on the fibrillated polyester fiber with a 5-30 wt % diethylenetriamine aqueous solution to obtain an aminated polyester fiber;

[0011] S3, in the presence of zinc acetate catalyst, using small pieces of waste polyester fabric and diethylenetriamine to undergo aminolysis reaction to obtain a polyester aminolysis solution;

[0012] S4, diluting the polyester aminolysis solution with 5 to 10 times the volume of water, and reacting with ethylene glycol glycidyl ether to prepare a crosslinking solution;

[0013] S5. Take the aminated polyester fiber, immerse it in a cross-linking solution, perform cross-linking and composite treatment, and then dry it to obtain a polyester-based composite hydrophilic material.

[0014] Furthermore, the surface amination treatment process is preferably carried out at 80-140°C.

[0015] Furthermore, the surface amination treatment time is preferably 5 to 15 minutes.

[0016] Furthermore, in the aminolysis reaction, the appropriate amount of diethylenetriamine is 3 to 5 times the mass of the waste polyester fabric.

[0017] Furthermore, the aminolysis reaction is preferably carried out under reflux at 160-175° C. to ensure that all polyester fibers can be completely aminolyzed.

[0018] More preferably, the aminolysis reaction may be first carried out at 110-120° C. for 25-40 minutes, and then heated to 160-175° C. for 30-45 minutes.

[0019] Furthermore, the present invention preferably dilutes the polyester aminolysis solution with water, heats it to 100-110° C., adds ethylene glycol glycidyl ether, stirs it for 1-3 minutes, and then cools it to 60-80° C. to carry out a crosslinking reaction to prepare a crosslinking solution.

[0020] Wherein, the amount of ethylene glycol glycidyl ether is preferably 0.75 to 1.1 times the volume of the polyester aminolysis solution.

[0021] Furthermore, the cross-linking reaction time is preferably 10 to 30 minutes.

[0022] Furthermore, in the present invention, the aminated polyester fiber is immersed in a crosslinking solution for crosslinking and composite treatment, preferably first placed at 50-80° C. for 2-4 hours and then placed at room temperature overnight.

[0023] Finally, the aminated polyester fiber after the cross-linking composite treatment is taken out, washed with water, and then freeze-dried to prepare the polyester-based composite hydrophilic material of the present invention.

[0024] By adopting the preparation method of the present invention, a fluffy polyester-based composite hydrophilic material is finally prepared. The static water contact angle thereof is tested to be no greater than 30°, and the material has excellent hydrophilic properties.

[0025] Therefore, the present invention also provides the use of the polyester-based composite hydrophilic material as an adsorption material, especially as an adsorption material in the field of water treatment.

[0026] More specifically, the polyester-based composite hydrophilic material of the present invention can be used as an adsorption material and applied in fields such as dye wastewater treatment.

[0027] The present invention forms a hydrophilic structure with an amino group on the surface of the polyester fiber through the aminolysis effect of diethylenetriamine on the surface of the polyester fiber, thereby changing the hydrophobic surface of the polyester fiber into a hydrophilic surface; further, the present invention obtains a cross-linking liquid by cross-linking the aminolysis liquid obtained by completely aminolyzing the polyester fiber, and further cross-linking and solidifying the aminated polyester fiber with the cross-linking liquid, thereby finally obtaining a polyester-based composite hydrophilic material with good hydrophilic properties.

[0028] The composite hydrophilic material of the present invention is composed of surface-aminated polyester fibers and a gel formed by curing a crosslinking solution. The gel binds the aminated polyester fibers together and allows the material to maintain a specific shape. Both materials contain a large number of amine groups, resulting in excellent hydrophilic properties. Furthermore, the composite hydrophilic material exhibits a dense pore structure formed by crosslinking of the completely aminolysis products and a macroporous structure formed between the surface-aminated polyester fibers, giving the prepared material a high specific surface area and pore volume, thereby enhancing its adsorption capacity.

[0029] The invention uses waste polyester fabric as raw material, which is of great significance for the effective utilization of waste resources and environmental protection. The invention has a simple preparation process, high efficiency, low energy consumption, low cost, no pollution, and can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a scanning electron microscope image of fibrillated polyester fiber.

[0031] Figure 2 This is the macroscopic morphology and scanning electron microscope image of the composite hydrophilic material prepared in Example 1.

[0032] Figure 3 The static water contact angle comparison between the composite hydrophilic material prepared in Example 1 and the untreated polyester fiber.

[0033] Figure 4 The adsorption performance of the composite hydrophilic material prepared in Example 1 on methylene blue.

[0034] Figure 5 This is the static water contact angle of the composite hydrophilic material prepared in Example 2.

[0035] Figure 6 This is the static water contact angle of the composite hydrophilic material prepared in Example 3.

[0036] Figure 7 This is the static water contact angle of the composite hydrophilic material prepared in Example 4.

[0037] Figure 8 This is the static water contact angle of the composite hydrophilic material prepared in Example 5.

[0038] Figure 9 This is the static water contact angle of the composite hydrophilic material prepared in Example 6.

[0039] Figure 10 This is the static water contact angle of the composite hydrophilic material prepared in Example 7.

[0040] Figure 11 This is the static water contact angle of the composite hydrophilic material prepared in Example 8.

[0041] Figure 12 This is the static water contact angle of the composite hydrophilic material prepared in Example 9.

[0042] Figure 13 This is the static water contact angle of the composite hydrophilic material prepared in Example 10.

[0043] Figure 14 This is the static water contact angle of the composite hydrophilic material prepared in Example 11.

[0044] Figure 15 This is the static water contact angle of the composite hydrophilic material prepared in Example 12.

[0045] Figure 16 This is the static water contact angle of the composite hydrophilic material prepared in Example 13. Implementation Method

[0046] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention so that those skilled in the art can better understand and utilize the present invention, but are not intended to limit the scope of protection of the present invention.

[0047] Unless otherwise specified, the production processes, experimental methods or detection methods involved in the embodiments and comparative examples of the present invention are conventional methods in the prior art, and their names and / or abbreviations are conventional names in the field and are very clear and unambiguous in the relevant fields of use. Those skilled in the art can understand the conventional process steps based on the names and apply the corresponding equipment, and implement them according to conventional conditions or the conditions recommended by the manufacturer.

[0048] The various instruments, equipment, raw materials or reagents used in the embodiments of the present invention are not particularly limited in their sources and are all conventional products that can be purchased through regular commercial channels or prepared according to conventional methods well known to those skilled in the art. Example

[0049] Example 1

[0050] The waste polyester fabric is cut into small pieces, put into a crusher, and further sheared to fibrillate the fiber part to obtain fibrillated polyester fiber.

[0051] Figure 1 A scanning electron microscope image of fibrillated polyester fiber is given. While the fabric is sheared, loosened and dispersed, the fibers split axially under the action of shear and mechanical friction, and tiny microfibrils are split on the fiber surface, achieving a partial fibrillation effect of the fibers, which is beneficial to increase the degree of subsequent amination reaction.

[0052] 0.2 g of fibrillated polyester fiber was weighed and placed in 20 ml of a 20% diethylenetriamine aqueous solution, and immersed in the solution for reaction at 130° C. for 10 minutes to obtain an aminated polyester fiber with the surface subjected to an amination treatment.

[0053] Weigh 1 g of small pieces of waste polyester fabric into a round-bottom flask with a stirrer and a reflux condenser, add 4 g of diethylenetriamine and 0.01 g of zinc acetate, first react at 120 ° C for 30 min, then heat to 170 ° C for 20 min to ensure complete aminolysis of the fiber to obtain a polyester aminolysis solution.

[0054] 2 ml of polyester aminolysis solution was added to 10 ml of deionized water, heated to 110° C., 2 ml of ethylene glycol glycidyl ether was added, stirred for 1 minute, cooled to 60° C., stirred and reacted for 10 minutes to prepare a crosslinking solution.

[0055] Weigh 0.2 g of aminated polyester fiber, completely immerse it in the above cross-linking solution, stand it at 60° C. for 2 h, then leave it at room temperature overnight, take it out, wash it with deionized water, and freeze-dry it to prepare a polyester-based composite hydrophilic material.

[0056] Figure 2These are the macromorphology and scanning electron microscope images of the prepared polyester-based composite hydrophilic material. It can be seen that the composite hydrophilic material has a fluffy appearance and a rich pore structure. Further, from the SEM image, it can be observed that the composite hydrophilic material is full of a dense pore structure formed by cross-linking of complete aminolysis products and a macroporous structure formed between aminated polyester fibers, thereby giving the composite hydrophilic material a high specific surface area and pore volume, and enhancing its adsorption capacity.

[0057] Since the composite hydrophilic material structure contains a large number of amino groups, it gives the material good water wettability. After testing, its static water contact angle is only 4°, while the static water contact angle of untreated polyester fiber is 110°. Therefore, the present invention changes the polyester fiber from hydrophobic to hydrophilic. The specific test results are as follows: Figure 3 .

[0058] The composite hydrophilic material prepared by the present invention also has good adsorption capacity, such as Figure 4 As shown, after testing, it has good adsorption performance for 1g / L methylene blue solution, and the adsorption amount can reach 500mg / g, and can be used as an adsorption material.

[0059] Example 2

[0060] The concentration of the diethylenetriamine aqueous solution in the surface amination treatment step was adjusted to 5%, and the treatment conditions were immersion reaction at 80° C. for 15 min. Other conditions were the same as in Example 1, and a polyester-based composite hydrophilic material was prepared.

[0061] like Figure 5 The static water contact angle of the tested composite hydrophilic material is 30°.

[0062] Example 3

[0063] The concentration of the diethylenetriamine aqueous solution in the surface amination treatment step was adjusted to 10%, and the treatment conditions were immersion reaction at 100° C. for 15 min. Other conditions were the same as in Example 1, and a polyester-based composite hydrophilic material was prepared.

[0064] like Figure 6 , the static water contact angle of the tested composite hydrophilic material is 10°.

[0065] Example 4

[0066] The concentration of the diethylenetriamine aqueous solution in the surface amination treatment step was adjusted to 10%, and the treatment conditions were immersion reaction at 140° C. for 5 min. Other conditions were the same as in Example 1, and a polyester-based composite hydrophilic material was prepared.

[0067] like Figure 7 The static water contact angle of the tested composite hydrophilic material is 20°.

[0068] Example 5

[0069] The concentration of the diethylenetriamine aqueous solution in the surface amination treatment step was adjusted to 20%, and the treatment conditions were immersion reaction at 140° C. for 10 min. Other conditions were the same as in Example 1, and a polyester-based composite hydrophilic material was prepared.

[0070] like Figure 8 , the static water contact angle of the tested composite hydrophilic material is 10°.

[0071] Example 6

[0072] The concentration of the diethylenetriamine aqueous solution in the surface amination treatment step was adjusted to 30%, and the treatment conditions were immersion reaction at 100° C. for 10 min. Other conditions were the same as in Example 1, and a polyester-based composite hydrophilic material was prepared.

[0073] like Figure 9 The static water contact angle of the tested composite hydrophilic material is 20°.

[0074] Example 7

[0075] The concentration of the diethylenetriamine aqueous solution in the surface amination treatment step was adjusted to 30%, and the treatment conditions were immersion reaction at 140° C. for 5 min. Other conditions were the same as in Example 1, and a polyester-based composite hydrophilic material was prepared.

[0076] like Figure 10 The static water contact angle of the tested composite hydrophilic material is 5°.

[0077] Example 8

[0078] In the step of adjusting the cross-linking solution preparation, 2 ml of polyester aminolysis solution was added to 15 ml of deionized water. Other conditions were the same as those in Example 1 to prepare a polyester-based composite hydrophilic material.

[0079] like Figure 11 , the static water contact angle of the tested composite hydrophilic material is 10°.

[0080] Example 9

[0081] In the step of adjusting the cross-linking solution preparation, 2 ml of polyester aminolysis solution was added to 20 ml of deionized water. Other conditions were the same as those in Example 1 to prepare a polyester-based composite hydrophilic material.

[0082] like Figure 12 , the static water contact angle of the tested composite hydrophilic material is 0°.

[0083] Example 10

[0084] The aminolysis reaction was adjusted to react at 110°C for 40 minutes, then heated to 175°C for 40 minutes. Ethylene glycol glycidyl ether (1.1 times the volume of the polyester aminolysis solution) was added to prepare a crosslinking solution. The aminated polyester fiber was immersed in the crosslinking solution, first at 80°C for 4 hours to allow crosslinking and composite, and then at room temperature overnight. All other conditions were the same as in Example 1 to prepare a polyester-based composite hydrophilic material.

[0085] like Figure 13 , the static water contact angle of the tested composite hydrophilic material is 0°.

[0086] Example 11

[0087] The surface amination treatment step involved adjusting the diethylenetriamine aqueous solution concentration to 10%, followed by immersion reaction at 100°C for 5 minutes. The aminolysis reaction was first conducted at 110°C for 25 minutes, then heated to 160°C for 25 minutes. Ethylene glycol glycidyl ether (0.75 times the volume of the polyester aminolysis solution) was added to prepare a crosslinking solution. The aminated polyester fiber was immersed in the crosslinking solution, first at 50°C for 2 hours for crosslinking and composite, and then at room temperature overnight. All other conditions were the same as in Example 1, yielding a polyester-based composite hydrophilic material.

[0088] like Figure 14 The static water contact angle of the tested composite hydrophilic material is 20°.

[0089] Example 12

[0090] The aminolysis reaction was adjusted to react at 115°C for 35 minutes, then heated to 170°C for 35 minutes; ethylene glycol glycidyl ether (1.1 times the volume of the polyester aminolysis solution) was added, stirred for 2 minutes, and then cooled to 80°C for a cross-linking reaction for 30 minutes to prepare a cross-linking solution; the aminated polyester fiber was immersed in the cross-linking solution, first placed at 80°C for 4 hours for cross-linking and composite, and then placed at room temperature overnight. All other conditions were the same as in Example 1 to prepare a polyester-based composite hydrophilic material.

[0091] like Figure 15 The static water contact angle of the tested composite hydrophilic material is 15°.

[0092] Example 13

[0093] The aminolysis reaction was adjusted to react at 110°C for 40 minutes, then heated to 165°C for 45 minutes. Ethylene glycol glycidyl ether was added to the polyester aminolysis solution dilution, stirred for 2 minutes, and then cooled to 80°C for a cross-linking reaction for 20 minutes to prepare a cross-linking solution. The aminated polyester fiber was immersed in the cross-linking solution, first placed at 70°C for 3 hours for cross-linking and composite, and then placed at room temperature overnight. All other conditions were the same as in Example 1 to prepare a polyester-based composite hydrophilic material.

[0094] like Figure 16, the static water contact angle of the tested composite hydrophilic material is 0°.

[0095] The above embodiments of the present invention do not describe all details in detail, nor do they limit the present invention to the above embodiments. Various changes, modifications, substitutions, and variations made by those skilled in the art without departing from the principles and purpose of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for preparing a polyester-based composite hydrophilic material, comprising: S1, shearing small pieces of waste polyester fabric in a pulverizer to partially fibrillate the fibers to obtain fibrillated polyester fibers; S2, performing surface amination treatment on the fibrillated polyester fiber with a 5-30 wt % diethylenetriamine aqueous solution to obtain an aminated polyester fiber; S3, in the presence of zinc acetate catalyst, using small pieces of waste polyester fabric and diethylenetriamine to undergo aminolysis reaction to obtain a polyester aminolysis solution; S4, diluting the polyester aminolysis solution with 5 to 10 times the volume of water, and reacting with ethylene glycol glycidyl ether to prepare a crosslinking solution; S5. Take the aminated polyester fiber, immerse it in a cross-linking solution, perform cross-linking and composite treatment, and then dry it to obtain a polyester-based composite hydrophilic material.

2. The method for preparing a polyester-based composite hydrophilic material according to claim 1, wherein The surface amination treatment is carried out at 80-140° C. for 5-15 minutes.

3. The method for preparing a polyester-based composite hydrophilic material according to claim 1, wherein The aminolysis reaction is carried out under reflux at 160-175° C., and the amount of diethylenetriamine used is 3-5 times the mass of the waste polyester fabric.

4. The preparation method according to claim 3, wherein The aminolysis reaction is first carried out at 110-120°C for 25-40 minutes, and then the temperature is raised to 160-175°C for 30-45 minutes.

5. The method for preparing a polyester-based composite hydrophilic material according to claim 1, wherein the polyester aminolysis solution is diluted with water, heated to 100-110°C, 0.75-1.1 times the volume of the polyester aminolysis solution of ethylene glycol glycidyl ether is added, stirred for 1-3 minutes, and then cooled to 60-80°C for cross-linking reaction to prepare a cross-linking solution.

6. The preparation method according to claim 5, wherein The cross-linking reaction time is 10 to 30 minutes.

7. The method for preparing a polyester-based composite hydrophilic material according to claim 1, wherein The aminated polyester fiber is immersed in a crosslinking solution, first placed at 50-80° C. for 2-4 hours, and then placed at room temperature overnight for crosslinking and composite treatment.

8. The polyester-based composite hydrophilic material prepared by the preparation method according to claim 1, wherein the static water contact angle of the polyester-based composite hydrophilic material is not greater than 30°.

9. Use of the polyester-based composite hydrophilic material according to claim 8 as an adsorption material.

10. Use of the polyester-based composite hydrophilic material according to claim 8 as an adsorption material for dye wastewater treatment.

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