Solvent-resistant degradable super-hydrophobic polylactic acid fabric and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer material preparation, and discloses a solvent-resistant degradable super-hydrophobic polylactic acid fabric and a preparation method thereof. The solvent-resistant degradable super-hydrophobic polylactic acid fabric is prepared by the following steps: carrying out melt spinning on poly-L-lactic acid (PLLA) and poly-D-lactic acid (PDLA) to obtain stereocomplex polylactic acid fibers (sc-PLA), carrying out one-in-one-button plain weaving to form a degradable sc-PLA fabric, spraying a poly-divinylbenzene (PDVB) solution, and carrying out infrared irradiation treatment, so as to obtain the solvent-resistant degradable super-hydrophobic polylactic acid fabric. Enabling the fabric and the PDVB material to generate cross-linking reaction to obtain the super-hydrophobic fabric. The super-hydrophobic Sc-PLA fabric prepared by the method has the characteristic of high water contact angle, and meanwhile, the super-hydrophobic Sc-PLA fabric has excellent solvent resistance and high temperature resistance, can be completely biodegraded, and is an environment-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 the advancement of science and technology and the improvement of environmental awareness, the demand for environmentally friendly and high-performance fabric materials is growing. Polylactic acid, as a completely biodegradable polymer material, has broad application prospects. However, conventional polylactic acid fabrics are insufficient in solvent resistance and hydrophobicity, and are difficult to meet the needs of specific fields. Therefore, it is of great practical significance to develop a solvent-resistant, super-hydrophobic and environmentally friendly polylactic acid fabric.

[0003] Polylactic acid (PLA) is an aliphatic polymer compound. 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 obtain lactide, which is then catalytically polymerized to generate PLA. It can be degraded to generate CO by landfill or bioaccumulation. 2 With H 2 O, does not cause pollution to the environment. Polydivinylbenzene (PDVB) is a new type of porous organic material, which not only has micro / nano structure and low free energy, but also has low preparation cost and 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 molecular chain structures of PLLA and PDLA complement each other to form a compact stereocrystalline structure (SC), forming sc-PLA under certain temperature conditions. However, the stereocrystalline structure of sc-PLA has good water resistance, solvent resistance, and high temperature resistance, which broadens the application field of polylactic acid fabrics and can be used to produce various textiles, such as clothing, household goods, and industrial products.

[0005] Patent CN109234834A discloses an electrospun polylactic acid fabric prepared from super-hydrophobic left-handed polylactic acid modified fibers. Although it has certain super-hydrophobic properties, the single homogeneous crystals result in low solvent resistance and few reuse times. 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 the polylactic acid fiber using a vapor deposition method and then modifying it using a fluorine compound or a silicon compound. Although the polylactic acid fiber has 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 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 also a completely biodegradable, environmentally friendly fabric, and has a simple production process, which is conducive to industrial production.

[0007] The 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. The sc-PLA fibers prepared from the 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, and drying the fabric to obtain the degradable super-hydrophobic 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 method for preparing the sc-PLA fiber comprises the following steps:

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

[0013] S12. After the sc-PLA nascent fibers are stretched in a hot water bath, heat treatment is performed for 10-30 minutes to obtain sc-PLA fibers. The heat treatment induces stereocrystallization and improves temperature resistance so that the fibers can be properly treated with infrared irradiation later.

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

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

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

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

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

[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 min.

[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 fiber of the solvent-resistant, degradable and super-hydrophobic polylactic acid fabric is 0.3-0.6 mm, and the thickness of the solvent-resistant, degradable and 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 prior art, the present invention first prepares sc-PLA fibers, and stereocrystallization can improve the solvent resistance and high temperature resistance of polylactic acid fabrics, and then processes them into woven fabrics, and then sprays a hydrophobic PDVB solution for infrared heat treatment to form solvent-resistant super-hydrophobic sc-PLA fabrics, thereby improving the application field of polylactic acid fabrics, and 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 the characteristics of high water contact angle (155.3°-162.7°), which can effectively prevent water penetration, and the polylactic acid fabric has excellent solvent resistance and high temperature resistance. In addition, the fabric is a completely biodegradable environmentally friendly material, has no pollution to the environment, 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 in conjunction with the accompanying drawings, in which:

[0029] Figure 1 A schematic diagram of hydrophobic treatment for spraying polydivinylbenzene solution provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the super-hydrophobic surface of the fabric 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 technical solutions in the embodiments of the present invention are described clearly and completely below. 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 creative work 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. The sc-PLA fibers prepared from PLLA / PDLA mixed particles were woven to obtain sc-PLA fabrics.

[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, and drying the fabric to obtain the degradable super-hydrophobic 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) Weigh corresponding masses of PLLA particles and PDLA particles, mix them in a mass ratio of 1:1 to form PLLA / PDLA particles, and melt-spin them in a twin-screw extruder at 220° C. and a spinning speed of 400 m / min to prepare sc-PLA primary fibers; and ultrasonically prepare a 1% PDVB spray solution.

[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 in a plain weave structure.

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

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

[0043] (6) The fabric of step (5) was fully dried in a 40°C forced air oven. A solvent-resistant superhydrophobic sc-PLA fabric was obtained. The obtained 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%, a water contact angle of 155.3°, and a water contact angle of 153.7° after 200 washes. The fabric was insoluble in dichloromethane.

[0044] Example 2

[0045] (1) Weigh corresponding masses of PLLA particles and PDLA particles, mix them in a mass ratio of 1:1 to form PLLA / PDLA particles, and melt-spin them in a twin-screw extruder at 220° C. and a spinning speed of 400 m / min to prepare sc-PLA primary fibers; and ultrasonically prepare a 3% PDVB spray solution.

[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 in a plain weave structure.

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

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

[0050] (6) The film of step (5) was fully dried in a 40°C forced air oven. A solvent-resistant superhydrophobic sc-PLA fabric was obtained. The obtained 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) Weigh corresponding masses of PLLA particles and PDLA particles, mix them in a mass ratio of 1:1 to form PLLA / PDLA particles, and prepare sc-PLA nascent fibers by melt spinning at 220° C. and a spinning speed of 600 m / min in a twin-screw extruder; and ultrasonically prepare a 5% PDVB spray solution.

[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 in a plain weave structure.

[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 of step (4) is subjected to infrared irradiation for 20 minutes.

[0057] (6) The film of step (5) was fully dried in a 40°C forced air oven. 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) Weigh corresponding masses of PLLA particles and PDLA particles, mix them in a mass ratio of 1:1 to form PLLA / PDLA particles, and prepare sc-PLA nascent fibers by melt spinning at 220° C. and a spinning speed of 500 m / min in a twin-screw extruder; and ultrasonically prepare a 3% PDVB spray solution.

[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 in a plain weave structure.

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

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

[0064] (6) The film of step (5) was fully dried in a 60°C forced air oven. 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 particles and PDLA particles of corresponding mass were weighed and mixed into PLLA / PDLA particles in a mass ratio of 1:1, and sc-PLA nascent fibers were prepared by melt spinning at 220° C. and a spinning speed of 540 m / min in a twin-screw extruder; and a 3% by mass 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 in a plain weave structure.

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

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

[0071] (6) The film of step (5) was fully dried in a 60°C forced air oven. 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] Weigh the corresponding mass of PLLA particles and PDLA particles, mix them into PLLA / PDLA particles in a mass ratio of 1:1, and prepare sc-PLA nascent fibers by melt spinning at 220℃ and a spinning speed of 400m / min in a twin-screw extruder. The sc-PLA nascent fibers were first drawn 3 times in a 60℃ hot water bath, and then heat-treated at 200℃ for 20min. The heat-treated sc-PLA fibers were woven into sc-PLA fabrics, and a 3% PDVB spray solution prepared by ultrasonic preparation was sprayed on the surface of the fabrics. Without infrared irradiation, the fabrics were fully dried in a 60℃ blast oven to obtain hydrophobic sc-PLA fabrics. The obtained sc-PLA fabrics had a thickness of 4mm, a fiber diameter of 0.5mm, a tensile strength of 287MPa, an elongation at break of 32%, a water contact angle of 157.7°, and a water contact angle of 135.6° after 200 water washings. The fabrics were insoluble in dichloromethane.

[0074] Comparative Example 2

[0075] Weigh the corresponding mass of PLLA particles and PDLA particles, mix them into PLLA / PDLA particles in a mass ratio of 1:1, and prepare sc-PLA primary fibers by melt spinning at 220°C and a spinning speed of 400m / min in a twin-screw extruder. Weave the sc-PLA fibers without heat treatment into sc-PLA fabrics, and spray the surface of the fabrics with a 3% PDVB spray solution prepared by ultrasonic preparation. After infrared irradiation, the fabrics are severely deformed and melted, and cannot be used for subsequent tests.

[0076] Comparative Example 3

[0077] Weigh the same mass of PLLA particles, melt-spin at 220℃ and 400m / min in a twin-screw extruder to prepare sc-PLA primary fibers, weave the prepared polylactic acid fibers into polylactic acid fabrics, and spray the surface of the fabric with a 3% PDVB spray solution prepared by ultrasonication. After infrared irradiation, the fabric is severely deformed and melted, and cannot be used for subsequent tests.

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. The sc-PLA fibers prepared from the PLLA / PDLA mixed particles were woven to obtain sc-PLA fabrics; 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 to obtain the degradable super-hydrophobic polylactic acid fabric.

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 preparation method of the sc-PLA fiber comprises the following steps: S11. melt spinning the PLLA / PDLA mixed particles to obtain sc-PLA primary fibers; S12. After the sc-PLA nascent fibers are stretched in a hot water bath, heat-treated for 10-30 minutes to obtain sc-PLA fibers.

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

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

6. The preparation method according to claim 3, characterized in that: The temperature of the heat treatment is 190-205°C.

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

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

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

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

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