A solvent-resistant, degradable super-hydrophobic polylactic acid fabric and preparation method thereof

Abstract

The invention belongs to the field of polymer material preparation technology, discloses a kind of solvent-resistant degradable super-hydrophobic polylactic acid fabric and preparation method thereof.The solvent-resistant degradable super-hydrophobic polylactic acid fabric is the stereocomposite polylactic acid fiber (sc-PLA) obtained by melt-spinning by left-handed polylactic acid (PLLA) and right-handed polylactic acid (PDLA), is woven into degradable sc-PLA fabric by the plain weave of one into one buckle, then carries out infrared irradiation treatment after spraying polydivinylbenzene (PDVB) solution, makes fabric and PDVB material produce cross-linking reaction, obtains super-hydrophobic fabric.The super-hydrophobic polylactic acid fabric prepared by the present invention has the characteristics of high water contact angle, while the super-hydrophobic sc-PLA fabric possesses excellent solvent resistance, high temperature resistance, and is completely biodegradable, for environmentally friendly fabric.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material preparation, and particularly relates to a solvent-resistant, degradable super-hydrophobic polylactic acid fabric and a preparation method thereof. Background Art

[0002] With technological advancements and rising environmental awareness, the demand for environmentally friendly, high-performance textile materials is growing. Polylactic acid (PLA), a fully biodegradable polymer, holds broad application potential. However, conventional PLA fabrics lack solvent resistance and hydrophobicity, making them difficult to meet the demands of specific applications. Therefore, developing a solvent-resistant, super-hydrophobic, and environmentally friendly PLA fabric is of great practical significance.

[0003] Polylactic acid (PLA) is an aliphatic polymer. It is fermented from bio-based materials such as plant starch or straw to form lactic acid, which is then chemically synthesized and purified to produce lactide. This is then catalytically polymerized to produce PLA. It can be degraded to CO2 and H2O through landfill or bioremediation, without causing environmental pollution. Polydivinylbenzene (PDVB) is a new porous organic material that combines micro / nanostructures with low free energy, is inexpensive to prepare, and has no secondary pollution.

[0004] Single polylactic acid fibers generally have poor thermal stability, poor hydrolysis resistance, and poor mechanical properties. When PLLA and PDLA are melt-blended in a certain ratio, the PLLA and PDLA molecular chains complement each other to form a compact stereocrystal structure (SC), forming sc-PLA under certain temperature conditions. However, the stereocrystal structure of sc-PLA is compact and has good water resistance, solvent resistance, and high temperature resistance, which broadens the application of polylactic acid fabrics and can be used to produce various textiles such as clothing, household items, and industrial products.

[0005] Patent CN109234834A discloses an electrospun polylactic acid fabric prepared from super-hydrophobic left-handed polylactic acid modified fiber. Although it has certain super-hydrophobic properties, the single homogeneous crystal causes its solvent resistance to be low and the number of reuses is small. Regarding the hydrophobic modification of the fabric surface, a hydrophobic finishing method for the fabric surface is often used to greatly improve the super-hydrophobic properties of the fabric. Patent CN 118166543 A discloses a super-hydrophobic polylactic acid fiber precursor, which is prepared by nano-structuring polylactic acid fibers using a vapor deposition method and then modifying them using fluorine compounds or silicon compounds. Although the polylactic acid fibers have super-hydrophobic properties, the surface coating is difficult to degrade, which causes environmental pollution to a certain extent. Summary of the Invention

[0006] In view of the shortcomings and deficiencies of the above-mentioned prior art, the object of the present invention is to provide a solvent-resistant, degradable super-hydrophobic polylactic acid fabric and a preparation method thereof. The polylactic acid fabric has a high water contact angle, excellent solvent resistance and high temperature resistance, and is a fully biodegradable, environmentally friendly fabric. The production process is simple, which is conducive to industrial production.

[0007] A first aspect of the present invention provides a method for preparing a solvent-resistant, degradable, super-hydrophobic polylactic acid fabric, comprising the following steps:

[0008] S1. sc-PLA fibers prepared from PLLA / PDLA mixed particles were woven to obtain sc-PLA fabrics;

[0009] S2. spraying the sc-PLA fabric with a polydivinylbenzene solution and then subjecting the fabric to infrared irradiation to cause a cross-linking reaction between the sc-PLA fabric and the polydivinylbenzene in the polydivinylbenzene solution, followed by drying to obtain the degradable superhydrophobic polylactic acid fabric.

[0010] Furthermore, in the PLLA / PDLA mixed particles, the mass ratio of PLLA particles to PDLA particles is 1:1.

[0011] Furthermore, in step S1, the preparation method of the sc-PLA fiber comprises the following steps:

[0012] S11. melt spinning the PLLA / PDLA mixed particles to obtain sc-PLA spun fibers;

[0013] S12. After stretching the sc-PLA spun fibers in a hot water bath, heat-treating them for 10-30 minutes to obtain sc-PLA fibers. The heat treatment induces stereocrystallization and improves temperature resistance, thereby facilitating subsequent infrared irradiation treatment.

[0014] Furthermore, in step S1, the weaving is specifically: using a plain weave structure to weave into sc-PLA fabric.

[0015] Furthermore, the melt spinning is specifically as follows: PLLA / PDLA mixed particles are extruded by a twin-screw extruder, with a spinning temperature of 220° C. and a spinning speed of 400-600 r / min.

[0016] Furthermore, the temperature of the hot water bath is 60° C., and the total stretching ratio of the stretching is 3 times.

[0017] Furthermore, the heat treatment temperature is 190-205°C.

[0018] Furthermore, in step S2, the concentration of the polydivinylbenzene solution is 1 wt%-5 wt%.

[0019] Furthermore, in step S2, the infrared irradiation treatment time is 10-30 minutes.

[0020] Furthermore, the drying temperature is 40° C. and the drying time is 20 minutes.

[0021] The second aspect of the present invention provides a solvent-resistant, degradable, super-hydrophobic polylactic acid fabric prepared by the above-mentioned preparation method.

[0022] Furthermore, the diameter of the sc-PLA fibers of the solvent-resistant, degradable, super-hydrophobic polylactic acid fabric is 0.3-0.6 mm, and the thickness of the solvent-resistant, degradable, super-hydrophobic polylactic acid fabric is 3-5 mm.

[0023] Furthermore, the solvent-resistant, degradable super-hydrophobic polylactic acid fabric has a water contact angle of 155.3°-162.7°, a strength of 264MPa-300MPa, is insoluble in dichloromethane, and after 200 washes, the water contact angle of the super-hydrophobic fabric remains at 153.7°-160.9°.

[0024] Compared with the existing technology, the present invention first prepares sc-PLA fibers, and stereocrystallization can improve the solvent resistance and high temperature resistance of polylactic acid fabrics. The fibers are then processed into woven fabrics, and then sprayed with a hydrophobic PDVB solution for infrared heat treatment to form solvent-resistant super-hydrophobic sc-PLA fabrics, thereby expanding the application areas of polylactic acid fabrics. In addition, the sc-PLA fabrics have super-hydrophobic / degradable properties.

[0025] The solvent-resistant and high-temperature-resistant super-hydrophobic polylactic acid fabric of the present invention has the following advantages and beneficial effects:

[0026] (1) The super-hydrophobic polylactic acid fabric prepared by the present invention has a high water contact angle (155.3°-162.7°), which can effectively prevent water penetration. At the same time, the polylactic acid fabric has excellent solvent resistance and high temperature resistance. In addition, the fabric is a completely biodegradable and environmentally friendly material, which is pollution-free and meets the requirements of sustainable development.

[0027] (2) The preparation process is simple and low-cost. After repeated use for 200 times, the water contact angle still maintains the superhydrophobic property of 153.7°-160.9°, which realizes the superhydrophobicity and solvent resistance of polylactic acid fabric, and provides new ideas and methods for the development of environmentally friendly fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0029] Figure 1 A schematic diagram of a hydrophobic treatment process for spraying a polydivinylbenzene solution according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram showing the super-hydrophobicity of the fabric surface after the sc-PLA fabric and the polydivinylbenzene in the polydivinylbenzene solution undergo a cross-linking reaction by infrared irradiation treatment according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] The present invention provides a method for preparing a solvent-resistant, degradable, super-hydrophobic polylactic acid fabric, comprising the following steps:

[0033] S1. sc-PLA fabrics were obtained by weaving sc-PLA fibers prepared from PLLA / PDLA mixed particles.

[0034] In one embodiment of the present invention, the sc-PLA fabric is a plain weave structure prepared as the sc-PLA fabric, and the plain weave structure is woven with a density of one-in-one-button.

[0035] S2. spraying the sc-PLA fabric with a polydivinylbenzene solution and then subjecting the fabric to infrared irradiation to cause a cross-linking reaction between the sc-PLA fabric and the polydivinylbenzene in the polydivinylbenzene solution, followed by drying to obtain the degradable superhydrophobic polylactic acid fabric.

[0036] The process of spraying polydivinylbenzene solution is as follows Figure 1 As shown, the surface of the degradable super-hydrophobic polylactic acid fabric obtained by spraying has a hydrophobic layer, such as Figure 2 shown.

[0037] Example 1

[0038] (1) PLLA and PDLA particles of corresponding mass were weighed and mixed into PLLA / PDLA particles in a mass ratio of 1:1. Sc-PLA nascent fibers were prepared by melt spinning in a twin-screw extruder at 220°C and a spinning speed of 400 m / min. A 1% PDVB spray solution was prepared by ultrasonication.

[0039] (2) The sc-PLA fiber obtained in step (1) was first stretched 3 times in a 60°C hot water bath and then heat treated at 205°C for 10 min.

[0040] (3) The sc-PLA fibers obtained in step (2) are woven using a plain weave structure with one button in each.

[0041] (4) Evenly spraying the surface of the polylactic acid fabric obtained in step (3) with a spray solution having a mass fraction of 1% PDVB.

[0042] (5) The polylactic acid fabric prepared in step (4) was subjected to infrared irradiation for 10 minutes.

[0043] (6) The fabric from step (5) was fully dried in a forced air oven at 40°C. A solvent-resistant superhydrophobic sc-PLA fabric was obtained. The resulting sc-PLA fabric had a thickness of 3 mm, a fiber diameter of 0.3 mm, a tensile strength of 264 MPa, an elongation at break of 35%, and a water contact angle of 155.3°. After 200 washes, the water contact angle was 153.7°. The fabric was insoluble in dichloromethane.

[0044] Example 2

[0045] (1) PLLA and PDLA particles of corresponding mass were weighed and mixed into PLLA / PDLA particles in a mass ratio of 1:1. Sc-PLA nascent fibers were prepared by melt spinning in a twin-screw extruder at 220°C and a spinning speed of 400 m / min. A 3% PDVB spray solution was prepared by ultrasonication.

[0046] (2) The sc-PLA fiber obtained in step (1) was first stretched 3 times in a 60°C hot water bath and then heat treated at 200°C for 20 min.

[0047] (3) The sc-PLA fibers obtained in step (2) are woven using a plain weave structure with one button in each.

[0048] (4) Evenly spraying the surface of the polylactic acid fabric obtained in step (3) with a spray solution having a mass fraction of 3% PDVB.

[0049] (5) The polylactic acid fabric prepared in step (4) was subjected to infrared irradiation for 20 minutes.

[0050] (6) The film from step (5) was fully dried in a forced air oven at 40°C. A solvent-resistant superhydrophobic sc-PLA fabric was obtained. The resulting sc-PLA fabric had a thickness of 3.5 mm, a fiber diameter of 0.4 mm, a tensile strength of 296 MPa, an elongation at break of 36%, a water contact angle of 162.7°, and a water contact angle of 160.9° after 200 washes. The fabric was insoluble in dichloromethane.

[0051] Example 3

[0052] (1) PLLA and PDLA particles of corresponding mass were weighed and mixed into PLLA / PDLA particles in a mass ratio of 1:1. Sc-PLA nascent fibers were prepared by melt spinning in a twin-screw extruder at 220°C and a spinning speed of 600 m / min. A 5% PDVB spray solution was prepared by ultrasonication.

[0053] (2) The sc-PLA fiber obtained in step (1) was first stretched 3 times in a 60°C hot water bath and then heat treated at 200°C for 20 min.

[0054] (3) The sc-PLA fibers obtained in step (2) are woven using a plain weave structure with one button in each.

[0055] (4) Evenly spraying a spray solution with a mass fraction of 5% PDVB on the surface of the polylactic acid fabric obtained in step (3).

[0056] (5) The polylactic acid fabric prepared in step (4) was subjected to infrared irradiation for 20 minutes.

[0057] (6) The film from step (5) was fully dried in a forced air oven at 40°C. A solvent-resistant superhydrophobic sc-PLA fabric was obtained. The obtained sc-PLA fabric had a thickness of 5 mm, a fiber diameter of 0.6 mm, a tensile strength of 290 MPa, an elongation at break of 34%, a water contact angle of 158.6°, and a water contact angle of 157.2° after 200 washes. The fabric was insoluble in dichloromethane.

[0058] Example 4

[0059] (1) PLLA and PDLA particles of corresponding mass were weighed and mixed into PLLA / PDLA particles in a mass ratio of 1:1. Sc-PLA nascent fibers were prepared by melt spinning in a twin-screw extruder at 220°C and a spinning speed of 500 m / min. A 3% PDVB spray solution was prepared by ultrasonication.

[0060] (2) The sc-PLA fiber obtained in step (1) was first stretched 3 times in a 60°C hot water bath and then heat treated at 190°C for 30 min.

[0061] (3) The sc-PLA fibers obtained in step (2) are woven using a plain weave structure with one button in each.

[0062] (4) Evenly spraying the surface of the polylactic acid fabric obtained in step (3) with a spray solution having a mass fraction of 3% PDVB.

[0063] (5) The polylactic acid fabric prepared in step (4) was subjected to infrared irradiation for 20 minutes.

[0064] (6) The film from step (5) was fully dried in a forced air oven at 60°C. A solvent-resistant superhydrophobic sc-PLA fabric was obtained. The obtained sc-PLA fabric had a thickness of 4 mm, a fiber diameter of 0.5 mm, a tensile strength of 300 MPa, an elongation at break of 31%, a water contact angle of 161.8°, and a water contact angle of 160.2° after 200 washes. The fabric was insoluble in dichloromethane.

[0065] Example 5

[0066] (1) PLLA and PDLA particles of corresponding mass were weighed and mixed into PLLA / PDLA particles in a mass ratio of 1:1. Sc-PLA nascent fibers were prepared by melt spinning in a twin-screw extruder at 220°C and a spinning speed of 540 m / min. A 3% PDVB spray solution was prepared by ultrasonication.

[0067] (2) The sc-PLA fiber obtained in step (1) was first stretched 3 times in a 60°C hot water bath and then heat treated at 200°C for 30 min.

[0068] (3) The sc-PLA fibers obtained in step (2) are woven using a plain weave structure with one button in each.

[0069] (4) Evenly spraying the surface of the polylactic acid fabric obtained in step (3) with a spray solution having a mass fraction of 3% PDVB.

[0070] (5) The polylactic acid fabric prepared in step (4) was subjected to infrared irradiation for 20 minutes.

[0071] (6) The film from step (5) was fully dried in a forced air oven at 60°C. A solvent-resistant superhydrophobic sc-PLA fabric was obtained. The obtained sc-PLA fabric had a thickness of 4 mm, a fiber diameter of 0.5 mm, a tensile strength of 297 MPa, an elongation at break of 28%, a water contact angle of 159.7°, and a water contact angle of 158.1° after 200 washes. The fabric was insoluble in dichloromethane.

[0072] Comparative Example 1

[0073] PLLA and PDLA pellets were weighed and mixed in a 1:1 mass ratio to form PLLA / PDLA pellets. Sc-PLA spun fibers were melt-spun in a twin-screw extruder at 220°C and a spinning speed of 400 m / min. The sc-PLA fibers were first drafted 3 times in a 60°C hot water bath and then heat-treated at 200°C for 20 min. The heat-treated sc-PLA fibers were woven into sc-PLA fabrics. The fabric surface was sprayed with a 3% (mass fraction) PDVB solution prepared by ultrasonication. The fabric was then dried in a 60°C forced air oven without infrared irradiation to produce a hydrophobic sc-PLA fabric. The resulting sc-PLA fabric had a thickness of 4 mm and a fiber diameter of 0.5 mm. It exhibited a tensile strength of 287 MPa, an elongation at break of 32%, and a water contact angle of 157.7°. After 200 washes, the water contact angle remained at 135.6°. The fabric was insoluble in dichloromethane.

[0074] Comparative Example 2

[0075] PLLA and PDLA pellets were weighed and mixed in a 1:1 mass ratio to form PLLA / PDLA pellets. Sc-PLA spun fibers were prepared by melt spinning in a twin-screw extruder at 220°C and a spinning speed of 400 m / min. The unheated sc-PLA fibers were then woven into sc-PLA fabrics. A 3% PDVB spray solution, prepared by ultrasonication, was sprayed onto the fabric surface. After infrared irradiation, the fabrics severely deformed and melted, making them unusable for subsequent testing.

[0076] Comparative Example 3

[0077] Equal masses of PLLA pellets were melt-spun in a twin-screw extruder at 220°C and a spinning speed of 400 m / min to produce sc-PLA spun fibers. These PLA fibers were then woven into PLA fabrics. A 3% PDVB spray solution, prepared by ultrasonic treatment, was sprayed onto the fabric surface. After infrared irradiation, the fabrics severely deformed and melted, making them unusable for subsequent testing.

Claims

1. A method for preparing a solvent-resistant, degradable super-hydrophobic polylactic acid fabric, characterized in that: The preparation method comprises the following steps: S1. sc-PLA fibers prepared from PLLA / PDLA mixed particles were woven to obtain sc-PLA fabrics; S2. The sc-PLA fabric is sprayed with a polydivinylbenzene solution and then subjected to infrared irradiation treatment so that the sc-PLA fabric and the polydivinylbenzene in the polydivinylbenzene solution produce a cross-linking reaction to obtain the degradable super-hydrophobic polylactic acid fabric; The preparation method of the sc-PLA fiber comprises the following steps: S11. melt spinning the PLLA / PDLA mixed particles to obtain sc-PLA spun fibers; S12. After stretching the sc-PLA spun fibers in a hot water bath, heat-treating them for 10-30 minutes to obtain sc-PLA fibers.

2. The preparation method according to claim 1, characterized in that In the PLLA / PDLA mixed particles, the mass ratio of PLLA particles to PDLA particles is 1:

1.

3. The preparation method according to claim 1, characterized in that In step S1, the weaving is specifically: using a plain weave structure to weave into sc-PLA fabric.

4. The preparation method according to claim 1, characterized in that The temperature of the hot water bath is 60° C., and the total stretching ratio of the stretching is 3 times.

5. The preparation method according to claim 1, characterized in that The temperature of the heat treatment is 190-205°C.

6. The preparation method according to claim 1, characterized in that In step S2, the concentration of the polydivinylbenzene solution is 1 wt%-5 wt%.

7. The preparation method according to claim 1, characterized in that In step S2, the infrared irradiation treatment time is 10-30 minutes.

8. The solvent-resistant, degradable super-hydrophobic polylactic acid fabric prepared according to the preparation method according to any one of claims 1 to 7.

9. The solvent-resistant, degradable super-hydrophobic polylactic acid fabric according to claim 8, characterized in that: The sc-PLA fiber diameter of the solvent-resistant, degradable, super-hydrophobic polylactic acid fabric is 0.3-0.6 mm, and the thickness of the solvent-resistant, degradable, super-hydrophobic polylactic acid fabric is 3-5 mm.

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