Sun-resistant polylactic acid fabric containing microcapsules and preparation method of sun-resistant polylactic acid fabric

Abstract

The invention relates to a sunscreen polylactic acid fabric containing microcapsules and a preparation method of the sunscreen polylactic acid fabric. The sunscreen polylactic acid fabric provided by the invention can be prepared by the following steps: firstly, preparing microcapsules containing rutin; secondly, doping the rutin-containing microcapsules into polylactic acid particles to prepare rutin-containing microcapsule / polylactic acid composite particles; thirdly, spinning by adopting a melt spinning process to prepare a rutin-containing microcapsule / polylactic acid composite fiber; finally, the microcapsule / polylactic acid composite fiber containing rutin is spun into yarn, the yarn is woven into fabric, and the fabric is the sunscreen polylactic acid fabric containing microcapsules. The ultraviolet transmittance T (UVA)% of the prepared sunscreen polylactic acid fabric is lower than 5% and meets the national standard; after 10 times of water washing, the sunscreen function of the sunscreen polylactic acid fabric is still stable and is not obviously weakened.

Description

Technical Field

[0001] This invention belongs to the field of fabric preparation technology, specifically relating to a sun-protective polylactic acid fabric containing microcapsules and its preparation method. Background Technology

[0002] In recent years, people have gained a more comprehensive understanding of sunlight. The previous view was that sunbathing was beneficial to health, but now it is recognized that excessive exposure to ultraviolet (UV) radiation can be harmful. Therefore, it is necessary to understand UV radiation and its serious impact on humans, and to take measures to treat textiles with UV protection to prevent the body from being harmed by UV rays.

[0003] According to the results published by the World Health Organization, excessive exposure to ultraviolet radiation can not only cause dark spots on the skin, but also suppress the skin's immune response, cause abnormalities in deoxyribonucleic acid (DNA), lead to cancer, and may also cause cataracts and partial blindness.

[0004] Currently, the commonly used UV-protective finishing methods are padding and coating, using UV reflectors and absorbers. Padding with UV absorbers is employed because UV absorbers can convert light energy, transforming high-energy ultraviolet rays into low-energy heat, or shorter-wavelength or harmless electromagnetic waves. Unlike UV reflectors, which reflect ultraviolet rays to exposed areas like the face and eyes, thus reducing the risk of illness, UV absorbers do not reflect ultraviolet rays.

[0005] Currently, improving the sun protection efficacy of fabrics is a research hotspot; however, key technologies remain difficult to overcome or have shortcomings. Rutin has the function of absorbing solar ultraviolet rays; however, its binding force with polylactic acid (PLA) fibers is weak, making it difficult to apply to PLA fibers and prone to shedding; its use in sun protection finishing of PLA fibers is rarely reported. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the first objective of the present invention is to provide a sun-protective polylactic acid fabric containing microcapsules, which has excellent sun protection effect.

[0007] The sun-protective polylactic acid (PLA) fabric of the present invention can be prepared by the following method: First, using gum arabic, β-cyclodextrin, and rutin as raw materials, microcapsules containing rutin are prepared; second, the microcapsules containing rutin are incorporated into PLA particles to obtain microcapsule / PLA composite particles containing rutin; third, the microcapsule / PLA composite particles containing rutin are spun using a melt spinning process to obtain microcapsule / PLA composite fibers containing rutin; finally, the microcapsule / PLA composite fibers containing rutin are spun into yarn, and the yarn is woven into fabric, wherein the fabric is a sun-protective PLA fabric containing microcapsules.

[0008] The second objective of this invention is to provide a method for preparing a sun-protective polylactic acid fabric containing microcapsules, comprising the following steps:

[0009] (1) Dissolve gum arabic and β-cyclodextrin in deionized water, stir in a water bath at 80-85°C for 20-40 min, cool to room temperature, add rutin, and homogenize emulsify at a stirring speed of 7000-9000 r / min for 3-5 min to obtain an emulsion; spray dry the emulsion to obtain microcapsules containing rutin.

[0010] Preferably, the ratio of gum arabic, β-cyclodextrin, rutin and deionized water is 1g:(1-3)g:(5-7)g:(60-80)mL.

[0011] (2) The microcapsules containing rutin were incorporated into polylactic acid particles and granulated using a granulator to obtain microcapsules / polylactic acid composite particles containing rutin.

[0012] Preferably, the ratio of the rutin-containing microcapsules to polylactic acid is 1g:(100-120)g, and the granulation temperature is 280-290℃.

[0013] (3) The microcapsule / polylactic acid composite particles containing rutin prepared in step (2) are spun by melt spinning process to obtain microcapsule / polylactic acid composite fibers containing rutin.

[0014] Preferably, the spinning temperature range of the melt spinning process is 260-280℃, the spinning speed is 2600-2800m / min, the spinneret has 24 holes with a hole diameter of 0.25*0.75, and the cooling method is ring blowing; the pump supply is controlled by a metering pump to be 22-24g / min during spinning.

[0015] (4) The microcapsule / polylactic acid composite fiber containing rutin prepared in step (3) is spun into yarn, and the yarn is woven into fabric, wherein the fabric is a sunscreen polylactic acid fabric containing microcapsules.

[0016] This invention has the following significant features:

[0017] (1) In this invention, rutin has the function of absorbing solar ultraviolet rays; however, its binding force with polylactic acid (PLA) fibers is weak, making it difficult to apply to PLA fibers and easy to fall off; there are few reports on its use in sun protection finishing of PLA fibers. The applicant of this invention accidentally discovered that PLA fibers can be prepared by incorporating microcapsules containing rutin into PLA particles; the PLA fibers have excellent sun protection properties.

[0018] (2) The present invention prepares sunscreen polylactic acid fiber through melt spinning process. The entire production process is simple, inexpensive, and has little environmental pollution. It has broad application prospects.

[0019] (3) The UV transmittance T(UVA)% of the sun-protective polylactic acid fabric prepared by the present invention is less than 5%, which meets the national standard; after 10 washes, the sun protection function of the sun-protective polylactic acid fabric is still very stable and has not been significantly weakened. Detailed Implementation

[0020] Example 1

[0021] A sun-protective polylactic acid fabric containing microcapsules, the fabric being prepared using the following method:

[0022] (1) Dissolve 1g gum arabic and 2g β-cyclodextrin in 70mL of deionized water, stir in a water bath at 83℃ for 30min, cool to room temperature, add 6g rutin, and homogenize and emulsify at a stirring speed of 8000r / min for 4min to obtain an emulsion; spray dry the emulsion to obtain microcapsules containing rutin.

[0023] (2) 10g of rutin-containing microcapsules were mixed into 1100g of polylactic acid granules and granulated using a granulator at a granulation temperature of 285℃ to obtain rutin-containing microcapsule / polylactic acid composite granules.

[0024] (3) The rutin-containing microcapsule / polylactic acid composite particles prepared in step (2) are spun by melt spinning to obtain rutin-containing microcapsule / polylactic acid composite fibers; the spinning temperature range of the melt spinning process is 270℃, the spinning speed is 2700m / min, the spinneret is selected with 24 holes and the hole diameter is 0.25*0.75, and the ring blowing cooling method is adopted; the pump supply is controlled by a metering pump to be 23g / min during spinning.

[0025] (4) The microcapsule / polylactic acid composite fiber containing rutin prepared in step (3) is spun into yarn, and the yarn is woven into fabric, wherein the fabric is a sunscreen polylactic acid fabric containing microcapsules.

[0026] Example 2

[0027] A sun-protective polylactic acid fabric containing microcapsules, the fabric being prepared using the following method:

[0028] (1) Dissolve 1g gum arabic and 1g β-cyclodextrin in 60mL of deionized water, stir in an 80℃ water bath for 20min, cool to room temperature, add 5g rutin, and homogenize and emulsify at a stirring speed of 7000r / min for 3min to obtain an emulsion; spray dry the emulsion to obtain microcapsules containing rutin.

[0029] (2) 10g of rutin-containing microcapsules were mixed into 1000g of polylactic acid granules and granulated using a granulator at a granulation temperature of 280℃ to obtain rutin-containing microcapsule / polylactic acid composite granules.

[0030] (3) The rutin-containing microcapsule / polylactic acid composite particles prepared in step (2) are spun by melt spinning to obtain rutin-containing microcapsule / polylactic acid composite fibers; the spinning temperature range of the melt spinning process is 260℃, the spinning speed is 2600m / min, the spinneret is selected with 24 holes and the hole diameter is 0.25*0.75, and the ring blowing cooling method is adopted; the pump supply is controlled by a metering pump to be 22g / min during spinning.

[0031] (4) The microcapsule / polylactic acid composite fiber containing rutin prepared in step (3) is spun into yarn, and the yarn is woven into fabric, wherein the fabric is sunscreen polylactic acid fabric b containing microcapsules.

[0032] Example 3

[0033] A sun-protective polylactic acid fabric containing microcapsules, the fabric being prepared using the following method:

[0034] (1) Dissolve 1g gum arabic and 3g β-cyclodextrin in 80mL of deionized water, stir in a water bath at 85℃ for 40min, cool to room temperature, add 7g rutin, and homogenize and emulsify at a stirring speed of 9000r / min for 5min to obtain an emulsion; spray dry the emulsion to obtain microcapsules containing rutin.

[0035] (2) 10g of rutin-containing microcapsules were mixed into 1200g of polylactic acid granules and granulated using a granulator at a granulation temperature of 290℃ to obtain rutin-containing microcapsule / polylactic acid composite granules.

[0036] (3) The rutin-containing microcapsule / polylactic acid composite particles prepared in step (2) are spun by melt spinning to obtain rutin-containing microcapsule / polylactic acid composite fibers; the spinning temperature range of the melt spinning process is 280℃, the spinning speed is 2800m / min, the spinneret is selected with 24 holes and the hole diameter is 0.25*0.75, and the ring blowing cooling method is adopted; the pump supply is controlled by a metering pump to be 24g / min during spinning.

[0037] (4) The microcapsule / polylactic acid composite fiber containing rutin prepared in step (3) is spun into yarn, and the yarn is woven into fabric, wherein the fabric is sunscreen polylactic acid fabric c containing microcapsules.

[0038] Comparative Example A

[0039] Compared with Example 1, in this Comparative Example A, rutin was not added, that is, the step of "adding 6g of rutin" in step (1) was deleted, and other preparation methods were carried out according to the preparation method of Example 1 to obtain sunscreen polylactic acid fabric d.

[0040] Comparative Example B

[0041] Compared with Example 1, in this Comparative Example B, the amount of microcapsules containing rutin was reduced, that is, "10g of microcapsules containing rutin" in step (2) was changed to "1g of microcapsules containing rutin". Other preparation methods were carried out according to the preparation method of Example 1, and sunscreen polylactic acid fabric e was obtained.

[0042] Performance evaluation test:

[0043] Polylactic acid fabrics a, b, c, d, and e prepared according to the specific embodiments 1-3 and comparative examples A-B of this invention were selected. The sun protection function of the fabrics was tested according to GB / T 17032-1997 "Test Method for Ultraviolet Transmittance of Fabrics". Ultraviolet transmittance T (%) was used as the evaluation index for sun protection function. The definition of ultraviolet transmittance T (%) is: the ratio of the ultraviolet radiation intensity with a sample to the radiance without a sample. T was calculated as follows:

[0044] T = (I1 / I0) × 100%

[0045] Where: I0—ultraviolet radiation intensity without a sample; I1—ultraviolet radiation intensity with a sample.

[0046] The experimental instrument used was a Lambda 35 UV-Vis spectrometer. The sample preparation method was as follows: a dry, flat section of fabric at least 2 cm from the edge was taken and cut into 60mm × 60mm pieces. The experimental procedure was as follows: before testing, the instrument parameters were set as follows: the wavelength scanning range was set to 200~400nm, the scanning wavelength interval to 1nm, the testing speed to high speed, and the test option to transmittance T%. After setting the instrument parameters, the sample was placed in the instrument without the sample clamp to zero the instrument. When the transmittance T% displayed was 100%, the instrument was calibrated. Then, the sample to be tested was placed in the instrument. The samples measured were freshly prepared and after 10 standard washes. The test results are shown in Table 1 below:

[0047] Table 1

[0048]

[0049] Chinese national standards define textiles with a UVA transmittance (T(UVA)%) of less than 5% as "UV-protective products." Table 1 shows a comparison of the UV transmittance of polylactic acid (PLA) fabrics (a, b, c, d, e) prepared in Examples 1-3 and Comparative Examples A-B. It can be seen that the T(UVA)% of the PLA fabrics prepared in Examples 1-3 are all below 5%, meeting the national standard. Examples 1-3 are significantly superior to Comparative Examples A-B in terms of sun protection indicators. After 10 washes, the sun protection function of the PLA fabrics remains stable without significant weakening. Performance evaluation test results indicate that the addition of rutin and the amount of rutin-containing microcapsules both have a significant impact on the sun protection function of PLA fabrics.

Claims

1. A method for preparing a sun-protective polylactic acid fabric containing microcapsules, characterized in that, The preparation method includes the following steps: (1) Dissolve gum arabic and β-cyclodextrin in deionized water, stir in a water bath at 80-85°C for 20-40 min, cool to room temperature, add rutin, and homogenize and emulsify at a stirring speed of 7000-9000 r / min for 3-5 min to obtain an emulsion; spray dry the emulsion to obtain microcapsules containing rutin. (2) Microcapsules containing rutin were incorporated into polylactic acid particles and granulated using a granulator to obtain microcapsules / polylactic acid composite particles containing rutin. (3) The microcapsule / polylactic acid composite particles containing rutin prepared in step (2) are spun by melt spinning process to obtain microcapsule / polylactic acid composite fibers containing rutin. (4) The microcapsule / polylactic acid composite fiber containing rutin prepared in step (3) is spun into yarn, and the yarn is woven into fabric, wherein the fabric is a sunscreen polylactic acid fabric containing microcapsules.

2. The method for preparing a sun-protective polylactic acid fabric containing microcapsules according to claim 1, characterized in that, The ratio of gum arabic, β-cyclodextrin, rutin and deionized water used in step (1) is 1g:(1-3)g:(5-7)g:(60-80)mL.

3. The method for preparing a sun-protective polylactic acid fabric containing microcapsules according to claim 1, characterized in that, In step (2), the ratio of rutin-containing microcapsules to polylactic acid is 1g:(100-120)g, and the granulation temperature is 280-290℃.

4. The method for preparing a sun-protective polylactic acid fabric containing microcapsules according to claim 1, characterized in that, The spinning temperature range of the melt spinning process in step (3) is 260-280℃, the spinning speed is 2600-2800m / min, the spinneret is selected with 24 holes and a hole diameter of 0.25*0.75, and the ring blowing cooling method is adopted; the pump supply is controlled by a metering pump to be 22-24g / min during spinning.

5. A sun-protective polylactic acid fabric containing microcapsules, characterized in that, It is prepared by the method described in any one of claims 1 to 4.

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