A luminous fiber capable of judging degradation status and its preparation method

Abstract

The present invention relates to a luminescent fiber capable of detecting degradation and a preparation method thereof. The method comprises the following steps: Step 1: preparing a hybrid luminescent material using europium chloride, α-thiophenoyltrifluoroacetone, 1,10-phenanthroline, and a fourth component; Step 2: mixing the hybrid luminescent material with PBAT and granulating the mixture to obtain a luminescent PBAT masterbatch; and Step 3: mixing the luminescent PBAT masterbatch with PBAT and spinning the mixture to obtain a luminescent fiber capable of detecting degradation. The method uses rare earth europium ions as raw materials and synthesizes the hybrid luminescent material by regulating the type and content of "antenna" ligands and the interaction between the europium ions and the ligands. The hybrid luminescent material exhibits heat resistance and can effectively reduce the melt viscosity of PBAT, allowing the luminescent component to be uniformly dispersed in the PBAT fiber. Furthermore, because the structure of the fourth component is similar to some segments in PBAT, when PBAT degrades, the fourth component also degrades accordingly, resulting in a decrease in its luminescence intensity, thereby enabling degradation detection.

Description

Technical Field

[0001] The present invention relates to a luminescent fiber capable of judging degradation conditions and a preparation method thereof, belonging to the technical field of luminescent fibers. Background Art

[0002] Polybutylene terephthalate-adipate (PBAT), a polymer copolymerized from terephthalic acid, adipic acid, and butanediol, has attracted considerable attention due to its excellent mechanical properties, thermal stability, and biodegradability without the need for composting. Developing PBAT nonwoven materials and expanding their applications in filtration, filling, and reinforcement is of great significance. However, PBAT's high melt viscosity makes it difficult to withstand the stretching under high airflow, resulting in poor meltblown spinnability and large fiber diameters in the resulting nonwoven. Chinese patent document CN116971092A discloses a PBAT meltblown nonwoven fabric and a method for preparing the meltblown air flow field. The fabrication of PBAT meltblown nonwoven fabric is achieved by modifying the meltblowing process, for example. Increasing the temperature can reduce interactions between molecular chains, thereby lowering viscosity and increasing fluidity. However, high temperatures can cause some PBAT to degrade, affecting the performance of the final product. Online determination of the degree of degradation has been a challenge in this field.

[0003] Develop uniformly distributed luminescent fibers. When PBAT degrades, its luminescence intensity under ultraviolet light will change, thereby enabling online judgment of degradation conditions. Patent CN104610957A discloses organic rare earth europium luminescent polyester and its preparation method. The polyester prepared by this method can achieve luminescence performance in DMF solution, but it is difficult to meet the luminescence performance requirements in the absence of solvent or other solvent scenarios. In addition, the luminescent material synthesis process disclosed in the prior art is complex, and its dispersibility in polyethylene terephthalate is poor, making it difficult to significantly reduce its melt viscosity, and therefore cannot meet the requirements for application in non-woven materials. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the purpose of the present invention is to provide a luminescent fiber and a preparation method thereof that can determine the degradation status, thereby solving the problems of poor high-temperature resistance of the luminescent material, uncontrollable luminescence performance, uneven dispersion in polybutylene terephthalate-adipate (PBAT), and inability to significantly reduce the melt viscosity of PBAT.

[0005] The technical solutions of the present invention are as follows:

[0006] A method for preparing a luminescent fiber capable of determining degradation conditions comprises the following steps:

[0007] Step 1: europium chloride, α-thiopheneyltrifluoroacetone (TTA), 1,10-phenanthroline (phen) and the fourth component are sequentially added to anhydrous ethanol, stirred at room temperature for 1 to 3 hours, and dried and crushed to obtain a hybrid luminescent material;

[0008] Step 2: The hybrid luminescent material obtained in step 1 and polybutylene terephthalate-adipate (PBAT) are mixed and granulated in a twin-screw extruder to obtain a hybrid luminescent PBAT masterbatch;

[0009] Step 3: The hybrid luminescent PBAT masterbatch obtained in step 2 is mixed with polybutylene terephthalate-adipate (PBAT), and after spinning, a luminescent fiber that can judge the degradation status is obtained.

[0010] According to a preferred embodiment of the present invention, in step 1, the fourth component is a complex of one or more of stearic acid, adipic acid, benzoic acid, and 3-aminopropyltriethoxysilane.

[0011] According to the preferred embodiment of the present invention, in step 1, the molar ratio of europium chloride, α-thenoyltrifluoroacetone (TTA), 1,10-phenanthroline and the fourth component is 1:(1-5):(0.5-3):(0.1-10).

[0012] Preferably, according to the present invention, in step 1, the mass volume ratio of europium chloride to anhydrous ethanol is 1:(20-100), unit: g / mL.

[0013] According to a preferred embodiment of the present invention, in step 1, the drying is first performed by forced air drying at 80° C. for 30 minutes to remove anhydrous ethanol, followed by vacuum drying at 80° C. for 5 hours.

[0014] Preferably, according to the present invention, in step 2, the molar ratio of terephthalic acid to hexanediol in the polybutylene terephthalate-adipate (PBAT) is 1:(1.6-3).

[0015] Further preferably, in step 2, the molecular weight distribution of the polybutylene terephthalate-adipate (PBAT) is less than 3, and the intrinsic viscosity is 0.5 dL / g to 0.79 dL / g.

[0016] Preferably, according to the present invention, in step 2, the hybrid luminescent material is 0.5-50% by mass of polybutylene terephthalate-adipate (PBAT); and the extrusion granulation temperature is 215-225°C.

[0017] According to a preferred embodiment of the present invention, in step 3, the hybrid luminescent PBAT masterbatch is 0.1% to 3% of the mass of polybutylene terephthalate-adipate (PBAT).

[0018] According to the preferred embodiment of the present invention, in step 3, the spinning forming method is melt spinning, melt blown spinning or spun bond spinning.

[0019] Further preferably, the temperature of the melt spinning is 190-235°C, and the speed of the melt spinning is 900-4000 m / min; the temperature of the melt blown spinning is 200-235°C, the drafting air flow pressure on both sides of the spinneret is 0.05-0.1 MPa, and the distance between the spinneret and the receiving web forming system is 45-55 cm.

[0020] A luminescent fiber capable of judging degradation conditions is prepared by adopting the above preparation method.

[0021] Preferably, according to the present invention, the excitation wavelength of the luminescent fiber capable of judging degradation conditions is 300-400 nm, and the luminescent wavelength is 600-630 nm.

[0022] The technical features and beneficial effects of the present invention are as follows:

[0023] 1. This invention uses rare earth europium ions as raw materials. By regulating the type and content of "antenna" ligands and the interaction between europium ions and ligands, a luminescent material suitable for PBAT nonwovens is synthesized. This luminescent material has good heat resistance and can effectively reduce the melt viscosity of PBAT, allowing the luminescent component to be evenly dispersed throughout the PBAT fibers.

[0024] 2. By adding a fourth component to the hybrid luminescent material, the present invention significantly lowers the melting temperature of PBAT. Specifically, at the same temperature, the viscosity of PBAT is significantly reduced, resulting in a more uniform dispersion of the hybrid luminescent material within PBAT, making it more suitable for subsequent spinning. Furthermore, because the structure of the fourth component is similar to some segments in PBAT, it degrades when PBAT degrades, resulting in a decrease in its luminescence intensity, thus enabling the determination of degradation.

[0025] 3. The degradation-detectable luminescent fiber prepared by the present invention has excellent luminescence performance, allowing real-time determination of degradation status based on the fiber's luminescence level. It also offers advantages such as low production cost, excellent fiber quality, and ease of industrial production.

[0026] 4. The luminescent fiber provided in the present invention that can determine the degradation status can adjust the luminescence intensity according to the proportion of each component. It is expected to be widely used in the field of degradable materials as a component for online determination of fiber degradation status, and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Actual pictures of luminescent fibers that can be used to determine different degradation conditions under ultraviolet light.

[0028] Figure 2 The DSC temperature rise curves of the luminescent fiber with different luminescent component ratios and addition amounts can be used to judge the degradation situation.

[0029] Figure 3 Excitation (a) and emission (b) spectra of luminescent fibers composed of different hybrid luminescent materials that can determine degradation status.

[0030] Figure 4 The emission spectra of hybrid luminescent materials with different luminescent component ratios. DETAILED DESCRIPTION

[0031] The present invention will be further described below by way of specific examples, but is not limited thereto.

[0032] The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials used are commercially available unless otherwise specified.

[0033] Example 1

[0034] A method for preparing a luminescent fiber capable of determining degradation conditions comprises the following steps:

[0035] Step 1: Weigh 25.8 g of europium chloride, 66.6 g of α-thiopheneyltrifluoroacetone, and 18 g of 1,10-phenanthroline respectively, pour the three into a beaker, add 1000 mL of anhydrous ethanol to dissolve, stir at room temperature for 1 hour, add 28.5 g of stearic acid, continue stirring at room temperature for 1 hour, and air dry at 80°C for 30 minutes to remove anhydrous ethanol. Then, vacuum dry at 80°C for 6 hours and crush to obtain a hybrid luminescent material;

[0036] The molar ratio of europium chloride, α-thenoyltrifluoroacetone, 1,10-phenanthroline and stearic acid is 1:3:1:1;

[0037] Step 2: The hybrid luminescent material obtained in step 1 and polybutylene terephthalate-adipate (PBAT) are extruded and granulated in a twin-screw extruder to obtain a hybrid luminescent PBAT masterbatch;

[0038] The molar ratio of terephthalic acid and hexanediol in PBAT is 1:2, the molecular weight distribution is 2, and the intrinsic viscosity is 0.6 dL / g; the hybrid luminescent material is 30% by mass of PBAT, and the extrusion granulation temperature is 220°C;

[0039] Step 3: The hybrid luminescent PBAT masterbatch obtained in step 2 is mixed with polybutylene terephthalate-adipate (PBAT) chips at a mass ratio of 1:30, and after melt spinning, a luminescent fiber that can judge the degradation status is obtained;

[0040] The melt spinning temperature is 190-230° C., and the melt spinning speed is 1000 m / min.

[0041] The breaking strength of the degradation-detectable luminescent fiber prepared in this embodiment is 3.2 cN / dtex, and the mass ratio of the hybrid luminescent material in the degradation-detectable luminescent fiber is 1%.

[0042] The actual picture of the luminescent fiber capable of judging degradation status prepared in this embodiment under ultraviolet light is as follows: Figure 1 As shown, it can be achieved by Figure 1 It can be seen that the luminescent fiber prepared by the present invention can effectively emit light in red.

[0043] Example 2

[0044] A method for preparing a luminescent fiber capable of determining degradation conditions comprises the following steps:

[0045] Step 1: Weigh 25.8 g of europium chloride, 66.6 g of α-thiophenoyltrifluoroacetone, 18 g of 1,10-phenanthroline, and 12.2 g of benzoic acid, pour them into a beaker in turn and add 800 mL of anhydrous ethanol to dissolve them. Stir at room temperature for 2 hours until fully mixed. Dry with air at 80°C for 30 minutes to remove anhydrous ethanol. Then, vacuum dry at 80°C for 4 hours and crush to obtain a hybrid luminescent material.

[0046] Step 2: The hybrid luminescent material obtained in step 1 and polybutylene terephthalate-adipate (PBAT) are extruded and granulated in a twin-screw extruder to obtain a hybrid luminescent PBAT masterbatch;

[0047] Among them, the molar ratio of terephthalic acid and hexanediol in PBAT is 1:2, the molecular weight distribution is 2, and the intrinsic viscosity is 0.6dL / g; the hybrid luminescent material is 40% by mass of PBAT, and the extrusion granulation temperature is 225°C;

[0048] Step 3: The hybrid luminescent PBAT masterbatch obtained in step 2 is mixed with polybutylene terephthalate-adipate (PBAT) chips at a mass ratio of 1:40, and after melt spinning, a luminescent fiber that can judge the degradation status is obtained;

[0049] The melt spinning temperature is 190-235° C., and the melt spinning speed is 1000 m / min.

[0050] The breaking strength of the degradation-determinable luminescent fiber prepared in this embodiment is 3.3 cN / dtex.

[0051] Example 3

[0052] A method for preparing a luminescent fiber capable of determining degradation conditions comprises the following steps:

[0053] Step 1: Weigh 25.8 g of europium chloride, 44.4 g of α-thiopheneyltrifluoroacetone, and 18 g of 1,10-phenanthroline respectively, pour the three into a beaker and add 900 mL of anhydrous ethanol to dissolve, stir at room temperature for 1 hour, then add 14.6 g of adipic acid, continue stirring at room temperature for 1 hour, and air dry at 80°C for 30 minutes to remove anhydrous ethanol, then vacuum dry at 80°C for 5 hours and crush to obtain a hybrid luminescent material;

[0054] Step 2: The hybrid luminescent material obtained in step 1 and polybutylene terephthalate-adipate (PBAT) are extruded and granulated in a twin-screw extruder to obtain a hybrid luminescent PBAT masterbatch;

[0055] The molar ratio of terephthalic acid and hexanediol in PBAT is 1:2, the molecular weight distribution is 2, and the intrinsic viscosity is 0.6 dL / g; the hybrid luminescent material is 30% by mass of PBAT, and the extrusion granulation temperature is 215°C;

[0056] Step 3: The hybrid luminescent PBAT masterbatch obtained in step 2 is mixed with polybutylene terephthalate-adipate (PBAT) chips at a mass ratio of 1::15, and melt-blown spinning is performed to obtain a luminescent fiber that can judge degradation status;

[0057] The temperature of melt-blown spinning is 195-230° C., the drafting air flow pressure on both sides of the spinneret is 0.08 MPa, and the distance between the spinneret and the receiving web forming system is 50 cm.

[0058] The average diameter of the luminescent fiber capable of judging degradation prepared in this embodiment is 4.5 μm.

[0059] Example 4

[0060] A method for preparing a luminescent fiber capable of determining degradation conditions comprises the following steps:

[0061] Step 1: Weigh 25.8 g of europium chloride, 66.6 g of α-thiopheneyltrifluoroacetone, and 18 g of 1,10-phenanthroline respectively, pour the three into a beaker and add 1200 mL of anhydrous ethanol to dissolve, stir at room temperature for 1 hour, add 22.1 g of coupling agent 3-aminopropyltriethoxysilane, continue stirring at room temperature for 1 hour, and air dry at 80°C for 30 minutes to remove anhydrous ethanol, then vacuum dry at 80°C for 5 hours and crush to obtain a hybrid luminescent material;

[0062] Step 2: The hybrid luminescent material obtained in step 1 and polybutylene terephthalate-adipate (PBAT) are extruded and granulated in a twin-screw extruder to obtain a hybrid luminescent PBAT masterbatch;

[0063] Among them, the molar ratio of terephthalic acid and hexanediol in PBAT is 1:2, the molecular weight distribution is 2, and the intrinsic viscosity is 0.6dL / g; the hybrid luminescent material is 30% by weight of PBAT, and the extrusion granulation temperature is 225°C;

[0064] Step 3: The hybrid luminescent PBAT masterbatch obtained in step 2 is mixed with polybutylene terephthalate-adipate (PBAT) chips at a mass ratio of 1::30, and after melt spinning, a luminescent fiber that can judge the degradation status is obtained;

[0065] The melt-blown spinning temperature is 200-235° C., the drafting air flow pressure on both sides of the spinneret is 0.08 MPa, and the distance between the spinneret and the receiving web forming system is 50 cm.

[0066] The average diameter of the luminescent fiber capable of judging degradation prepared in this embodiment is 5 μm.

[0067] Comparative Example 1

[0068] A method for preparing a luminescent fiber capable of determining degradation status, comprising the steps as described in Example 1, except that in step 1, the mass of stearic acid is 57 g, and the molar ratio of the four is 1:3:1:2.

[0069] Comparative Example 2

[0070] A method for preparing a luminescent fiber capable of determining degradation status, comprising the steps as described in Example 1, except that in step 1, the mass of stearic acid is 42.75 g, and the molar ratio of the four is 1:3:1:1.5.

[0071] Comparative Example 3

[0072] A method for preparing a luminescent fiber capable of determining degradation status, comprising the steps as described in Example 1, except that in step 1, the mass of stearic acid is 57 g, and the molar ratio of the four is 1:3:1:2;

[0073] In step 3, the mass ratio of the hybrid luminescent PBAT masterbatch to the polybutylene terephthalate-adipate (PBAT) slices is 1:15.

[0074] Comparative Example 4

[0075] A method for preparing a luminescent fiber capable of determining degradation status, comprising the steps as described in Example 1, except that in step 1, the mass of stearic acid is 42.75 g, and the molar ratio of the four is 1:3:1:1.5;

[0076] In step 3, the mass ratio of the hybrid luminescent PBAT masterbatch to the polybutylene terephthalate-adipate (PBAT) slices is 1:15.

[0077] Comparative Example 5

[0078] A method for preparing a luminescent fiber capable of determining degradation status, comprising the steps as described in Example 1, except that in step 3, the mass ratio of the hybrid luminescent PBAT masterbatch to the polybutylene terephthalate-adipate (PBAT) slice is 1:15.

[0079] Comparative Example 6

[0080] A method for preparing a luminescent fiber capable of determining degradation status, comprising the steps described in Example 1, except that, in step 1, stearic acid is not added.

[0081] Test example

[0082] 1. The luminescent fibers prepared in Example 1 and Comparative Examples 1 to 5 were subjected to temperature tests. The results are as follows: Figure 2 shown.

[0083] The heating test method is as follows: the sample is heated from room temperature to 240°C, held at this temperature for 1 minute, then cooled to -30°C, and then heated to 240°C, both at a rate of 10°C / min. The DSC heating curve is the second heating curve.

[0084] Depend on Figure 2 It can be seen that the melting point of PBAT is significantly reduced after the addition of hybrid luminescent materials, and the degree of reduction can be controlled by the amount of stearic acid added.

[0085] 2. The excitation wavelength and emission wavelength of the luminescent fibers capable of judging degradation prepared in Examples 1 to 4 and Comparative Example 6 were measured. The results are as follows: Figure 3 shown.

[0086] Depend on Figure 3 It can be seen that the excitation wavelengths of the luminescent fibers capable of determining degradation conditions prepared in Examples 1 to 4 of the present invention are all 300 to 400 nm, and the emission wavelengths are all 610 to 620 nm.

[0087] 3. The emission wavelength of the hybrid luminescent materials prepared in step 1 of Example 1 and Example 1 and Comparative Examples 2 to 3 was measured. The results are as follows: Figure 4 shown.

[0088] Depend on Figure 4 As can be seen, when the content of stearic acid in the fourth component decreases, its luminescence intensity also decreases significantly. Furthermore, because the structure of stearic acid, the fourth component, is similar to some segments in PBAT, when PBAT degrades, the fourth component stearic acid will also degrade accordingly, resulting in a weakening of its luminescence intensity, thus enabling the judgment of degradation.

[0089] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a luminescent fiber capable of determining degradation conditions, characterized in that: The steps are as follows: Step 1: europium chloride, α-thiopheneyltrifluoroacetone, 1,10-phenanthroline and the fourth component are sequentially added to anhydrous ethanol, stirred at room temperature for 1 to 3 hours, and dried and crushed to obtain a hybrid luminescent material; Wherein, the fourth component is a complex of one or more of stearic acid, adipic acid, benzoic acid, and 3-aminopropyltriethoxysilane; Step 2: The hybrid luminescent material obtained in step 1 and polybutylene terephthalate-adipate are mixed and granulated in a twin-screw extruder to obtain a hybrid luminescent PBAT masterbatch; Step 3: The hybrid luminescent PBAT masterbatch obtained in step 2 is mixed with polybutylene terephthalate-adipate, and after spinning, a luminescent fiber that can judge the degradation status is obtained.

2. The preparation method according to claim 1, wherein In step 1, the molar ratio of europium chloride, α-thenoyltrifluoroacetone, 1,10-phenanthroline and the fourth component is 1:(1-5):(0.5-3):(0.1-10).

3. The preparation method according to claim 1, wherein In step 1, the mass volume ratio of europium chloride to anhydrous ethanol is 1:(20-100), unit: g / mL; the drying is first performed by forced air drying at 80° C. for 30 minutes to remove anhydrous ethanol, and then vacuum drying at 80° C. for 5 hours.

4. The preparation method according to claim 1, wherein In step 2, the molecular weight distribution of the polybutylene terephthalate-adipate is less than 3, and the intrinsic viscosity is 0.5 dL / g to 0.79 dL / g.

5. The preparation method according to claim 1, wherein In step 2, the hybrid luminescent material is 0.5-50% by mass of polybutylene terephthalate-adipate; and the extrusion granulation temperature is 215-225°C.

6. The preparation method according to claim 1, wherein In step 3, the hybrid luminescent PBAT masterbatch is 0.1% to 3% of the mass of polybutylene terephthalate-adipate.

7. The preparation method according to claim 1, wherein In step 3, the spinning forming method is meltblown spinning or spunbond spinning.

8. The preparation method according to claim 7, wherein The temperature of the melt-blowing spinning is 200-235° C., the drafting air flow pressure on both sides of the spinneret is 0.05-0.1 MPa, and the distance between the spinneret and the receiving web forming system is 45-55 cm.

9. A luminescent fiber capable of determining degradation conditions, characterized in that: The luminescent fiber capable of judging degradation conditions is prepared by the preparation method according to any one of claims 1 to 8.

10. The luminescent fiber capable of determining degradation status according to claim 9, wherein: The excitation wavelength of the luminescent fiber capable of judging the degradation condition is 300-400 nm, and the luminescent wavelength is 600-630 nm.

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