PET (Polyethylene Terephthalate) fiber membrane with enhanced hydrophilicity and reflectivity and preparation method of PET fiber membrane

Abstract

The invention discloses a PET (polyethylene terephthalate) fiber membrane with enhanced hydrophilicity and reflectivity and a preparation method thereof, CaHPO4 is loaded on the surface of the PET fiber membrane, and the specific preparation method comprises the following steps: firstly, immersing the PET fiber membrane into a sodium alginate solution, then sequentially immersing the PET fiber membrane into a CaCl2 solution and a Na2HPO4 solution, and cleaning the PET fiber membrane with deionized water after immersing and taking out the PET fiber membrane each time in the midway, so as to finally prepare the CaHPO4 PET fiber membrane. According to the technical scheme disclosed by the invention, the hydrophilicity of the PET fiber membrane loaded with CaHPO4 is remarkably improved, not only is the hydrophilicity remarkably improved, but also the sunlight reflectivity and the infrared thermal emissivity of the PET fiber membrane loaded with CHPO4 are remarkably improved through tests, and the application range of the PET fiber membrane is expanded.

Description

Technical Field

[0001] The invention relates to the technical field of polymer diaphragms, and in particular to a PET fiber film with enhanced hydrophilicity and reflectivity and a preparation method thereof. Background Art

[0002] As a kind of polyester material, polyethylene terephthalate (PET) fiber has the advantages of high strength, good elasticity, high wear resistance, etc., and is widely used in packaging, electronic appliances, medical and health, construction, automobiles, clothing, environment and other fields. However, due to the lack of active groups in the main chain of the molecule and its high crystallinity, it has poor hydrophilicity and low surface energy, which seriously limits its use in certain application fields.

[0003] Therefore, improving the hydrophilicity of PET materials is an important research direction. There are many methods for modifying the hydrophilicity of PET surfaces. For example, Wang Mengze constructed a microporous structure by changing the interface shape to improve the material's moisture absorption capacity; Lu Sheng et al. coated a hydrophilic finishing agent on the PET surface to improve the material's hydrophilicity; Zhu Fangjian used the modified T.fusca cutinase to hydrolyze the ester bonds in PET fibers to produce hydrophilic groups, thereby improving its hydrophilicity.

[0004] The present application provides a method of using sodium alginate and Ca+ to undergo ion exchange to form a gel, which can form a hydrophilic coating on the surface of PET fiber after combining with the PET fiber to improve its hydrophilic and antistatic properties. Then, by using ion exchange, CaHPO4 is loaded on the PET fiber to significantly improve the hydrophilicity of the PET fiber film, while also improving the solar reflectivity and infrared thermal emissivity of the PET fiber film. Summary of the invention

[0005] The present invention provides a PET fiber film with enhanced hydrophilicity and reflectivity and a preparation method thereof. , which solves the problem of poor hydrophilicity and low reflectivity of the PET fiber membrane in the prior art, and modifies the PET fiber membrane to enhance the hydrophilicity, solar reflectivity and infrared thermal emissivity.

[0006] The embodiment of the present application provides a PET fiber membrane with enhanced hydrophilicity and reflectivity, wherein the surface of the PET fiber membrane is loaded with CaHPO4 with a loading rate of 10% to 12%.

[0007] The present application also provides a method for preparing a PET fiber film with enhanced hydrophilicity and reflectivity, which specifically comprises the following steps: S1 pre-treats the PET fiber membrane; S2 The PET fiber membrane pretreated in step S1 is immersed in a sodium alginate solution for a certain period of time, and then the PET fiber membrane is immersed in a CaCl2 solution and a Na2HPO4 solution in turn at a constant temperature. After the PET fiber membrane is taken out of the CaCl2 solution and the Na2HPO4 solution, it is washed with deionized water to obtain a PET fiber membrane loaded with CaHPO4.

[0008] Preferably, the pretreatment in step S1 is to wash the PET fiber membrane with acetone, ethanol and deionized ultrasonic waves for 10 minutes in sequence, and then dry it for later use.

[0009] Preferably, the concentration of the sodium alginate solution in step S2 is 0.004-0.006 mol / L.

[0010] Preferably, the concentration of the CaCl2 solution in step S2 is 0.15-0.25 mol / L, and the concentration of the Na2HPO4 solution is 0.1-0.2 mol / L.

[0011] Preferably, the Na2HPO4 solution may also be a Na2SiO3 solution.

[0012] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. The PET fiber membrane is first immersed in a sodium alginate solution, and then immersed in a CaCl2 solution and a Na2HPO4 solution in sequence to obtain a PET fiber membrane loaded with CaHPO4. Therefore, the problem of poor hydrophilicity and low reflectivity of the PET fiber membrane in the prior art is effectively solved. The hydrophilicity, solar reflectivity and infrared thermal emissivity of the PET fiber membrane are enhanced by modification, thereby expanding the application range of the PET fiber membrane.

[0013] 2. The PET fiber membrane is first immersed in a sodium alginate solution, a large number of hydroxyl groups are introduced into the surface of the PET fiber, and the surface chemical structure changes. The PET fiber membrane is then immersed in a CaCl2 solution to form an insoluble polymer fiber-like grid structure of calcium alginate in the PET fiber membrane, which further improves the hydrophilicity of the PET fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Characterization of infrared properties of CaHPO4-modified PET film, PET film and CaHPO4 in Example 1 of the present application; Figure 2 In Example 1 of the present application, the infrared emission performance of PET film and CaHPO4@PET-3 film was tested. DETAILED DESCRIPTION

[0015] The embodiments of the present application solve the problems of poor hydrophilicity and low reflectivity of PET fiber membranes in the prior art by providing a PET fiber membrane with enhanced hydrophilicity and reflectivity and a preparation method thereof, and modify the PET fiber membrane to enhance the hydrophilicity, solar reflectivity and infrared thermal emissivity.

[0016] The technical solution in the embodiment of the present application is to solve the above problems, and the overall idea is as follows: First, the PET fiber membrane was immersed in a sodium alginate solution, and then immersed in a CaCl2 solution and a Na2HPO4 solution in turn. After each immersion, it was washed with deionized water to finally obtain the CaHPO4@PET fiber membrane. The hydrophilicity of the CaHPO4-loaded PET fiber membrane was significantly improved, and the contact angle was reduced from 101° to 30°~32°. Not only the hydrophilicity was improved, but also the solar reflectivity and infrared thermal emissivity of the CaHPO4-loaded PET fiber membrane were significantly improved.

[0017] In order to better understand the above technical solution, Figure 1-2 And specific implementation methods are used to describe the above technical solutions in detail. Embodiment 1

[0018] (1) Pretreatment of PET fiber membrane The commercial PET fiber membrane was ultrasonically washed with acetone, ethanol and deionized water for 8-12 min respectively, the temperature was set to 50-70°C to remove organic matter and other impurities on the surface of the PET fiber membrane, and then dried for later use.

[0019] (2) Preparation of CaHPO4@PET fiber membrane ① Dissolve 100 mg of sodium alginate in 100 mL of deionized water to obtain a sodium alginate solution for later use; ② The PET fiber membrane reserved in step (1) is immersed in a sodium alginate solution at a constant temperature of 50-70°C for 20-28 h, and then the PET fiber membrane is immersed in a CaCl2 solution with a concentration of 0.15 mol / L at a constant temperature of 50-70°C for 40 min, washed with deionized water, and then immersed in a Na2HPO4 solution with a concentration of 0.15 mol / L at a constant temperature of 50-70°C for 40 min, washed with deionized water, and dried to obtain CaHPO4@PET-1. The CaHPO4 loading rate on the PET fiber membrane is 9.3wt%. The contact angle of CaHPO4@PET-1 is reduced from 101° to 31.9° as tested by a contact angle tester.

[0020] Embodiment 2 The concentrations of the CaCl2 solution and the Na2HPO4 solution in Example 1 were changed to 0.2 mol / L and 0.2 mol / L, respectively, and the rest were the same as in Example 1 to obtain CaHPO4@PET-2. The CaHPO4 loading rate on the PET fiber membrane was 10.2 wt%. The contact angle of CaHPO4@PET-2 was reduced from 101° to 31.2° when tested by a contact angle tester. Embodiment 3

[0021] The concentrations of the CaCl2 solution and the Na2HPO4 solution in Example 2 were changed to 0.3 mol / L and 0.3 mol / L, respectively, and the rest were consistent with Example 1 to obtain CaHPO4@PET-3. The CaHPO4 loading rate on the PET fiber membrane was 11.1 wt%. The contact angle of CaHPO4@PET-3 was reduced from 101° to 30.8° when tested by a contact angle tester.

[0022] The PET film and CaHPO4@PET-3 film were tested. Please refer to Figure 2 , PET film and CaHPO4@PET-3 film were tested in the test range of 0.25-15 μm. The `Rsolar (0.25~2.5 μm) and e̅IR (8~13 μm) of PET and CaHPO4@PET were calculated. The `Rsolar of PET is 78.17%, and the `Rsolar of CaHPO4@PET increases to 91.10%. The e̅IR of PET is 88.24%, and the e̅IR of CaHPO4@PET increases to 92.75%. The CaHPO4-modified PET film has high emissivity and reflectivity. The addition of CaHPO4 improves the high solar reflectivity and high infrared thermal emissivity of the PET film.

[0023] In summary, the hydrophilicity of the PET film loaded with CaHPO4 is significantly improved, and the emissivity and reflectivity are also significantly improved, which can expand the application range of the PET film. It can not only be used as a reflective film or an anti-reflective film in photovoltaic modules, liquid crystal displays, lighting industry, and automobiles, but can also be used in the preparation of Janus films and in the preparation of hydrophilic radiation cooling coatings.

[0024] In another embodiment, Na2HPO4 in step (2) of Example 1 is replaced by Na2SiO3 to prepare a PET film loaded with CaSiO3. After testing, the contact angle is reduced from 101° to 33.9°. CaSiO3 and calcium alginate are blended and loaded on the PET film, which also improves the mechanical properties of the PET film, has good anti-swelling properties, and can maintain a stable structure under different environments.

[0025] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A PET fiber membrane with enhanced hydrophilicity and reflectivity, wherein the surface of the PET fiber membrane is loaded with CaHPO4, and the loading rate is 10% to 12%.

2. A method for preparing a PET fiber film with enhanced hydrophilicity and reflectivity, characterized in that: The following steps are involved: S1 pre-treats the PET fiber membrane; S2 The PET fiber membrane pretreated in step S1 is immersed in a sodium alginate solution for a certain period of time, and then the PET fiber membrane is immersed in a CaCl2 solution and a Na2HPO4 solution in turn at a constant temperature. After the PET fiber membrane is taken out of the CaCl2 solution and the Na2HPO4 solution, it is washed with deionized water to finally obtain a PET fiber membrane loaded with CaHPO4.

3. The method according to claim 2, wherein the pretreatment in step S1 is to wash the PET fiber membrane with acetone, ethanol and deionized ultrasonic washing for 10 minutes in sequence, and then dry it for later use.

4. The method according to claim 2, wherein the concentration of the sodium alginate solution in step S2 is 0.004-0.006 mol / L.

5. The method according to claim 2, wherein the concentration of the CaCl2 solution in the step S2 is 0.15-0.25 mol / L, and the concentration of the Na2HPO4 solution is 0.1-0.2 mol / L.

6. The PET fiber film as claimed in claim 1, wherein the CaHPO4 may also be CaSiO3.

7. The PET fiber film according to claim 1, wherein the PET fiber film is used in the preparation of a Janus membrane or in the preparation of a hydrophilic radiation cooling coating.

Images