A sodium alginate composite membrane with excellent comprehensive performance and its preparation method and application

Abstract

The present invention belongs to the technical field of polymer composite materials, and specifically relates to a sodium alginate composite film with excellent comprehensive performance, a preparation method and application thereof, wherein the composite film is prepared from the following raw materials: sodium alginate, iron metal organic framework, and sorbitol. The present invention also provides a preparation method of the above-mentioned sodium alginate composite film material, and the prepared sodium alginate composite film material has excellent mechanical strength, elongation at break, toughness, ultraviolet blocking, high-energy blue light blocking, DPPH free radical scavenging activity (i.e., antioxidant activity), ammonia response color change, biodegradability and other properties, while maintaining a high visible light transparency, and the preparation process is simple, and has a wide range of application value in the fields of food packaging, smart materials, ammonia detection, environmental monitoring and safety.

Description

[0001] The invention belongs to the technical field of polymer materials, and specifically relates to a sodium alginate composite film with excellent comprehensive performance and a preparation method and application thereof. Background Art

[0002] Sodium alginate is a natural polymer material that is non-toxic, non-irritating, has good mechanical properties, is renewable, highly transparent, and has good plasticity. In particular, it has excellent biocompatibility and biodegradability, and does not produce immune effects in the human body.

[0003] Repel and can be metabolized and absorbed, it is one of the most promising degradable polymers at present. Sodium alginate is widely used in food packaging, drug delivery and printing and textile industry. But compared with traditional petrochemical materials, sodium alginate also has obvious disadvantages, such as poor water vapor barrier, poor ductility, no compression, low elongation at break, low crystallization rate, unsatisfactory heat resistance and other shortcomings. According to existing research, it is known that the performance of sodium alginate can be effectively improved by doping functional fillers into the sodium alginate matrix, and its application value is improved. The present invention uses sodium alginate as a matrix, and utilizes iron metal organic framework and sorbitol as fillers to improve the mechanical strength, elongation at break, toughness, ultraviolet blocking, high energy blue light blocking, DPPH free radical scavenging activity (i.e. antioxidant activity), ammonia response color change and other properties of sodium alginate composite materials, develops sodium alginate composite film materials with excellent comprehensive performance, and broadens its application in the fields of food packaging, intelligent materials, ammonia detection, environmental monitoring and safety. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a sodium alginate composite film with excellent comprehensive performance and a preparation method and application thereof. The composite material has excellent mechanical strength, elongation at break, toughness, ultraviolet blocking, high-energy blue light blocking, DPPH free radical scavenging activity (i.e., antioxidant activity), ammonia response color change and other properties, while maintaining high visible light transparency, and the composite material preparation process is simple, environmentally friendly, low-cost, and suitable for scaled-up production.

[0005] Technical solution of the present invention:

[0006] The present invention provides a sodium alginate composite film with excellent comprehensive performance, characterized in that it is composed of the following components in parts by weight: 100 parts of sodium alginate, 5 parts of iron metal organic framework, and 0-3 parts of sorbitol;

[0007] The iron metal organic framework is a nanoparticle, and its preparation method comprises the following steps:

[0008] (1) Weigh 72.45 parts of 2-indolecarboxylic acid and 25.2 parts of potassium hydroxide, add them to 1500 parts of methanol, and stir at room temperature for 2 h to obtain a uniform solution for later use;

[0009] (2) Dissolve 40.5 parts of ferric chloride hexahydrate in 1000 parts of methanol solution, and add the solution dropwise to the solution obtained in step (1). Stir the mixture at room temperature for 12 h, and then centrifuge, wash with ethanol, and dry to obtain an iron metal organic framework.

[0010] The present invention also provides a method for preparing the sodium alginate composite film with excellent comprehensive performance, which is characterized by comprising the following steps:

[0011] (1) Weigh 5 parts of an iron metal organic framework and add it to 8000 parts of deionized water, stirring at room temperature for 45 minutes to obtain a uniform dispersion of the iron metal organic framework for later use;

[0012] (2) Add 100 parts of sodium alginate to the dispersion obtained in step (1), and stir at room temperature for 30 min to obtain a uniform mixed solution for later use;

[0013] (3) Add 0-3 parts of sorbitol to the mixed solution of step (2), stir at 60°C for 2 hours to obtain a uniform film-forming solution for later use;

[0014] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed dish and dried in an oven at 60°C for 24 h to obtain a sodium alginate composite film with excellent comprehensive properties.

[0015] The sodium alginate composite film with excellent comprehensive performance can be used in food packaging, smart materials, ammonia detection, environmental monitoring and safety and other fields.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The sodium alginate composite film with excellent comprehensive performance prepared by the present invention has excellent mechanical strength, elongation at break, toughness, ultraviolet blocking, high-energy blue light blocking, DPPH free radical scavenging activity (i.e., antioxidant activity), ammonia response color change, biodegradability and the like, while maintaining high visible light transparency, and has wide application value in food packaging, smart materials, ammonia detection, environmental monitoring and safety and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a scanning electron microscope image of the iron metal organic framework involved in the present invention;

[0019] Figure 2 This is a physical photo of the sodium alginate composite membrane sample material prepared in Example 3. DETAILED DESCRIPTION

[0020] The present invention is described in detail below through examples. It is necessary to point out that the examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments based on the above content of the present invention. The parts of the raw materials are all parts by weight unless otherwise specified.

[0021] In the following specific embodiments and comparative example formulas and preparation methods, the sodium alginate is a product provided by Haohong Biopharmaceutical Technology Co., Ltd. (CAS No.: 9005-38-3); sorbitol is an analytically pure reagent provided by Yien Technology Development Co., Ltd.; potassium hydroxide is an analytically pure reagent provided by Xilong Science Co., Ltd. (CAS No.: 1310-58-3); methanol is an analytically pure reagent provided by Xilong Science Co., Ltd.; 2-indolecarboxylic acid is an analytically pure reagent provided by Huawei Ruike Chemical Co., Ltd. (CAS No.: 1477-50-5).

[0022] In the following specific embodiments and comparative example formulations and preparation methods, the iron metal organic framework is a nanoparticle, and its preparation method comprises the following steps:

[0023] (1) Weigh 72.45 parts of 2-indolecarboxylic acid and 25.2 parts of potassium hydroxide, add them to 1500 parts of methanol, and stir at room temperature for 2 h to obtain a uniform solution for later use;

[0024] (2) Dissolve 40.5 parts of ferric chloride hexahydrate in 1000 parts of methanol solution, and add the solution dropwise to the solution obtained in step (1). Stir the mixture at room temperature for 12 h, and then centrifuge, wash with ethanol, and dry to obtain an iron metal organic framework.

[0025] Example 1

[0026] A sodium alginate composite membrane with excellent comprehensive performance, characterized in that it is composed of the following components in parts by weight: 100 parts of sodium alginate, 5 parts of iron metal organic framework;

[0027] The preparation method comprises the following steps:

[0028] (1) Weigh 5 parts of an iron metal organic framework and add it to 8000 parts of deionized water, stirring at room temperature for 45 minutes to obtain a uniform dispersion of the iron metal organic framework for later use;

[0029] (2) Add 100 parts of sodium alginate to the dispersion obtained in step (1), and stir at room temperature for 30 min to obtain a uniform mixed solution for later use;

[0030] (3) Stir the mixed solution of step (2) at 60°C for 2 hours to obtain a uniform film-forming solution for later use;

[0031] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed dish and dried in an oven at 60°C for 24 h to obtain a sodium alginate composite film with excellent comprehensive properties.

[0032] Example 2

[0033] A sodium alginate composite membrane with excellent comprehensive performance, characterized in that it is composed of the following components in parts by weight: 100 parts of sodium alginate, 5 parts of iron metal organic framework, and 1 part of sorbitol;

[0034] The preparation method comprises the following steps:

[0035] (1) Weigh 5 parts of an iron metal organic framework and add it to 8000 parts of deionized water, stirring at room temperature for 45 minutes to obtain a uniform dispersion of the iron metal organic framework for later use;

[0036] (2) Add 100 parts of sodium alginate to the dispersion obtained in step (1), and stir at room temperature for 30 min to obtain a uniform mixed solution for later use;

[0037] (3) Add 1 part of sorbitol to the mixed solution of step (2), stir at 60°C for 2 hours to obtain a uniform film-forming solution for later use;

[0038] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed dish and dried in an oven at 60°C for 24 h to obtain a sodium alginate composite film with excellent comprehensive properties.

[0039] Example 3

[0040] A sodium alginate composite membrane with excellent comprehensive performance, characterized in that it is composed of the following components in parts by weight: 100 parts of sodium alginate, 5 parts of iron metal organic framework, and 3 parts of sorbitol;

[0041] The preparation method comprises the following steps:

[0042] (1) Weigh 5 parts of an iron metal organic framework and add it to 8000 parts of deionized water, stirring at room temperature for 45 minutes to obtain a uniform dispersion of the iron metal organic framework for later use;

[0043] (2) Add 100 parts of sodium alginate to the dispersion obtained in step (1), and stir at room temperature for 30 min to obtain a uniform mixed solution for later use;

[0044] (3) Add 3 parts of sorbitol to the mixed solution of step (2), stir at 60°C for 2 hours to obtain a uniform film-forming solution for later use;

[0045] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed dish and dried in an oven at 60°C for 24 h to obtain a sodium alginate composite film with excellent comprehensive properties.

[0046] Comparative Example

[0047] As a comparison standard of the above embodiments, the present invention provides a sodium alginate membrane prepared without an iron metal organic framework and sorbitol, comprising the following steps:

[0048] (1) Add 100 parts of sodium alginate to 8000 parts of deionized water, stir at room temperature for 30 minutes to obtain a uniform mixed solution for later use;

[0049] (2) Stir the mixed solution of step (1) at 60° C. for 2 h to obtain a uniform film-forming solution for later use;

[0050] (3) The film-forming solution obtained in step (2) is poured into a flat-bottomed dish and dried in an oven at 60°C for 24 h to obtain a sodium alginate film.

[0051] Structure and performance test:

[0052] The sodium alginate film prepared in the above comparative example and the sodium alginate composite film with excellent comprehensive performance prepared in the embodiment were subjected to structure and performance tests, wherein the UV-visible performance was tested by using a UV-visible spectrometer (Lamdba365, PerkinElmer Instruments), and the average UV transmittance was calculated with reference to GB / T 18830-2009; the tensile performance was tested in accordance with GB / T 1040-2006; the ammonia response test method was as follows: the sample film material was exposed to an ammonia environment, and the color change of the sample film material was observed.

[0053] The DPPH free radical scavenging experimental method is as follows:

[0054] In the experimental group, 0.2 g of the membrane sample was cut into pieces and soaked in 5 mL of ethanol. After soaking for 24 h, 2 mL of the supernatant of the soaking solution was extracted and set aside. Then, 1 ml of 50 mg / L DPPH solution was added to the 2 mL of the supernatant, and the mixture was shaken and placed at room temperature in the dark for 1 h. Then, the absorbance of the mixture at 517 nm (denoted as A) was measured using an ultraviolet spectrophotometer (Lambda750, PerkinElmer Instruments). sample ); for the control group, 1 mL of 50 mg / L DPPH solution was added to 2 mL of ethanol, and the mixture was shaken and placed in the dark at room temperature for 1 h; then, the absorbance of the mixture at 517 nm (denoted as A) was measured using an ultraviolet spectrophotometer (Lambda750, PerkinElmer Instruments). control);DPPH free radical scavenging rate (%)=100*(A control -A sample ) / A control .

[0055] The above performance test data is shown in Table 1.

[0056] Table 1 Sample performance test data

[0057] Group Example 1 Example 2 Example 3 Comparative Example 1 Average UV transmittance (%) 0.75 0.36 0.32 42.74 Average transmittance of high energy blue light (%) 6.69 6.46 6.27 76.12 Tensile strength (MPa) 79.71 81.23 83.71 76.4 Elongation at break (%) 12.48 12.81 13.02 12.07 <![CDATA[Toughness (MJ / m 3 )]]> 8.93 10.80 13.1 6.19

[0058] The results of the ammonia response test experiment show that the sodium alginate film material prepared in the comparative example is colorless and transparent. After being exposed to an ammonia environment, its color does not change, and it still presents colorless and transparent optical properties; the sodium alginate composite film material with excellent comprehensive performance prepared in Example 1 is brown, and its color changes to yellow when exposed to an ammonia environment; the sodium alginate composite film material with excellent comprehensive performance prepared in Example 2 is brown, and its color changes to yellow after being exposed to an ammonia environment; the sodium alginate composite film material with excellent comprehensive performance prepared in Example 3 is brown, and its color changes to yellow after being exposed to an ammonia environment.

[0059] The results of the DPPH free radical scavenging experiment show that the sodium alginate film material prepared in the comparative example has no antioxidant activity, while the sodium alginate composite film material with excellent comprehensive performance prepared in Example 1 has a DPPH free radical scavenging rate of 11.03%, that is, the sodium alginate composite film material with excellent comprehensive performance prepared in Example 1 has obvious antioxidant activity.

[0060] In summary, it can be seen from the sample performance test data (see Table 1) that the sodium alginate composite film material with excellent comprehensive performance prepared by the present invention has excellent mechanical strength, elongation at break, toughness, UV blocking, high-energy blue light blocking, DPPH free radical scavenging activity (i.e. antioxidant activity), ammonia response color change, biodegradability and other properties, while maintaining a high visible light transparency. The composite material preparation process is simple, environmentally friendly, low-cost, and suitable for scale-up production. It has wide application value in food packaging, smart materials, ammonia detection, environmental monitoring and safety and other fields.

[0061] The content of the present invention is not limited to the embodiments listed, and any equivalent changes made to the technical solution of the present invention by ordinary technicians in this field after reading the description of the present invention are covered by the claims of the present invention.

Claims

1. A sodium alginate composite membrane with excellent comprehensive performance, It is characterized in that The invention is composed of the following components in parts by weight: 100 parts of sodium alginate, 5 parts of iron metal organic framework, and 0-3 parts of sorbitol; The preparation method of the iron metal organic framework comprises the following steps: (1) Weigh 72.45 parts of 2-indolecarboxylic acid and 25.2 parts of potassium hydroxide, add them to 1500 parts of methanol, and stir at room temperature for 2 h to obtain a uniform solution for later use; (2) Dissolve 40.5 parts of ferric chloride hexahydrate in 1000 parts of methanol solution, and add the solution dropwise to the solution obtained in step (1). Stir the mixture at room temperature for 12 h, and then centrifuge, wash with ethanol, and dry to obtain an iron metal organic framework.

2. The method for preparing the sodium alginate composite film with excellent comprehensive performance according to claim 1, Features The steps include: (1) Weigh 5 parts of an iron metal organic framework and add them to 8000 parts of deionized water, stirring at room temperature for 45 minutes to obtain a uniform dispersion of the iron metal organic framework for later use; (2) Add 100 parts of sodium alginate to the dispersion obtained in step (1), and stir at room temperature for 30 min to obtain a uniform mixed solution for later use; (3) Add 0-3 parts of sorbitol to the mixed solution of step (2), stir at 60°C for 2 hours to obtain a uniform film-forming solution for later use; (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed dish and dried in an oven at 60°C for 24 h to obtain a sodium alginate composite film with excellent comprehensive properties.

3. Application of the sodium alginate composite film with excellent comprehensive performance according to claim 1, It is characterized in that Used in food packaging, smart materials, ammonia detection, and anti-oxidation.

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