Thermoplastic starch-based nanocomposite having excellent barrier properties and method for preparing the same
By adding tea polyphenols and rod-shaped zinc oxide nanoparticles to thermoplastic starch, a starch-based nanocomposite material with excellent barrier properties was prepared, which solved the shortcomings of existing materials in terms of performance and enabled wider application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUILIN UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2021-09-13
- Publication Date
- 2026-06-09
AI Technical Summary
Existing thermoplastic starch-based materials cannot meet high requirements in terms of mechanical properties, water vapor barrier properties, ultraviolet shielding properties, high-energy short-wave blue light blocking properties, and free radical scavenging activity, which affects the long-term preservation of food and medicine.
Thermoplastic starch-based nanocomposites were prepared by using thermoplastic starch as a base material and adding tea polyphenols and rod-shaped zinc oxide nanoparticles as fillers, through specific ratios and preparation methods, to enhance their barrier properties.
The prepared composite material has excellent mechanical properties, water vapor barrier properties, ultraviolet shielding properties, high-energy short-wave blue light blocking properties, and DPPH free radical scavenging activity. Moreover, the preparation process is simple, environmentally friendly, and low in cost, making it suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer composite materials technology, specifically relating to a thermoplastic starch-based nanocomposite material with excellent barrier properties and its preparation method. Background Technology
[0002] Biodegradable plastics, made from natural polymers, have become a hot research and development area internationally. Among numerous natural polymer materials, starch, due to its wide availability, renewability, edibility, low price, and biodegradability, has become one of the most promising biodegradable materials. To give starch plasticity similar to petroleum-based polymers, starch is usually mixed with plasticizers, causing the starch macromolecules to transform from a crystalline structure to an amorphous state, thus obtaining thermoplastic starch. However, thermoplastic starch contains a large number of hydroxyl groups, and the mechanical properties, water vapor barrier properties, ultraviolet shielding properties, high-energy short-wave blue light blocking properties, and free radical scavenging activity (i.e., antioxidant activity) of biodegradable film materials prepared from it often fail to meet higher packaging requirements, affecting the long-term preservation of food and pharmaceuticals. Therefore, improving the mechanical properties, water vapor barrier properties, ultraviolet shielding properties, high-energy short-wave blue light blocking properties, and free radical scavenging activity (i.e., antioxidant activity) of thermoplastic starch-based materials is of significant practical importance for broadening their application fields. Summary of the Invention
[0003] The purpose of this invention is to overcome the shortcomings of the prior art by providing a thermoplastic starch-based nanocomposite material with excellent barrier properties and its preparation method, using thermoplastic starch as the base material and tea polyphenols and rod-shaped zinc oxide nanoparticles as fillers. This composite material has excellent mechanical properties, water vapor barrier properties, ultraviolet shielding properties, high-energy short-wave blue light blocking properties, DPPH free radical scavenging activity (i.e., antioxidant activity), and low hygroscopicity. In addition, the preparation process of this composite film is simple, environmentally friendly, and low in cost, making it suitable for large-scale production.
[0004] The technical solution of the present invention:
[0005] A thermoplastic starch-based nanocomposite material with excellent barrier properties is characterized by being composed of the following components in parts by weight: 100 parts starch, 30 parts plasticizer, 6 parts tea polyphenols, and 1-7 parts rod-shaped zinc oxide nanoparticles.
[0006] The starch is corn starch; the plasticizer is glycerin.
[0007] The rod-shaped zinc oxide nanoparticles have a diameter of 50 nm and a length of 100–200 nm.
[0008] The preparation method of the rod-shaped zinc oxide nanoparticles includes the following steps:
[0009] Zinc acetate dihydrate was dissolved in 1,2-propanediol, and then deionized water was added and stirred until homogeneous. Sodium acetate was added to the above solution, stirred until homogeneous, and then heated to 150°C and refluxed for 1 hour. After centrifugation and drying, rod-shaped zinc oxide nanoparticles were obtained.
[0010] The mass ratio of deionized water, zinc acetate dihydrate, sodium acetate, and 1,2-propanediol is 3.15:5.48:6.15:86.3.
[0011] A method for preparing a thermoplastic starch-based nanocomposite material with excellent barrier properties includes the following steps:
[0012] (1) Add 100 parts of starch and 30 parts of plasticizer to 1200 parts of deionized water, stir for 30 minutes at room temperature, and then stir at 85°C to dissolve to obtain starch solution for later use;
[0013] (2) Disperse 6 parts of tea polyphenols in 800 parts of deionized water and stir for 1 hour to obtain a tea polyphenol solution for later use;
[0014] (3) Disperse 1 to 7 parts of rod-shaped zinc oxide nanoparticles in 800 parts of deionized water and stir for 1 hour to obtain a uniform dispersion for later use.
[0015] (4) Add the tea polyphenol solution obtained in step (2) and the rod-shaped zinc oxide nanoparticle dispersion obtained in step (3) to the starch solution obtained in step (1) and stir at 85°C for 1 hour to obtain a uniform film-forming liquid. Pour the film-forming liquid onto an organic glass dish and dry it in a vacuum oven at 50°C for 24 hours to obtain a thermoplastic starch-based nanocomposite material with excellent barrier properties.
[0016] Compared with the prior art, the present invention has the following beneficial effects:
[0017] The thermoplastic starch-based nanocomposite material prepared by this invention has excellent mechanical properties, water vapor barrier properties, ultraviolet shielding properties, high-energy short-wave blue light blocking properties, DPPH free radical scavenging activity (i.e. antioxidant activity) and low hygroscopicity. In addition, the preparation process of this composite film is simple, environmentally friendly, and low in cost, making it suitable for large-scale production. Detailed Implementation
[0018] To better explain the present invention, the present invention will be further explained in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.
[0019] In the following specific embodiments and comparative formulations and preparation methods, the starch used is corn starch (CAS No.: 9005-25-8), purchased from Aladdin Biochemical Technology Co., Ltd.; tea polyphenols are analytical grade reagents provided by Luoyang Tianluo Biotechnology Co., Ltd.; ethanol is analytical grade reagents provided by Fuyu Fine Chemical Co., Ltd.; zinc acetate dihydrate, anhydrous sodium acetate, and glycerol are analytical grade reagents provided by Xilong Chemical Co., Ltd.; 1,2-propanediol is analytical grade reagents provided by Aladdin Biochemical Co., Ltd.
[0020] In the following specific embodiments and comparative formulations and preparation methods, the rod-shaped zinc oxide nanoparticles are self-made nanoparticles (average diameter 50 nm, average length 100-200 nm), and the preparation method includes the following steps:
[0021] Zinc acetate dihydrate was dissolved in 1,2-propanediol, and then deionized water was added and stirred until homogeneous. Sodium acetate was added to the above solution, stirred until homogeneous, and then heated to 150°C and refluxed for 1 hour. After centrifugation and drying, rod-shaped zinc oxide nanoparticles were obtained.
[0022] The mass ratio of deionized water, zinc acetate dihydrate, sodium acetate, and 1,2-propanediol is 3.15:5.48:6.15:86.3.
[0023] Example 1
[0024] A thermoplastic starch-based nanocomposite material with excellent barrier properties is characterized by being composed of the following components in parts by weight: 100 parts starch, 30 parts glycerol, 6 parts tea polyphenols, and 1 part rod-shaped zinc oxide nanoparticles.
[0025] The preparation method includes the following steps:
[0026] (1) Add 100 parts starch and 30 parts glycerol to 1200 parts deionized water, stir for 30 minutes at room temperature, and then stir at 85°C to dissolve to obtain starch solution for later use;
[0027] (2) Disperse 6 parts of tea polyphenols in 800 parts of deionized water and stir for 1 hour to obtain a tea polyphenol solution for later use;
[0028] (3) Disperse 1 part of rod-shaped zinc oxide nanoparticles in 800 parts of deionized water and stir for 1 hour to obtain a uniform dispersion for later use.
[0029] (4) Add the tea polyphenol solution obtained in step (2) and the rod-shaped zinc oxide nanoparticle dispersion obtained in step (3) to the starch solution obtained in step (1) and stir at 85°C for 1 hour to obtain a uniform film-forming liquid. Pour the film-forming liquid onto an organic glass dish and dry it in a vacuum oven at 50°C for 24 hours to obtain a thermoplastic starch-based nanocomposite material with excellent barrier properties.
[0030] Example 2
[0031] A thermoplastic starch-based nanocomposite material with excellent barrier properties is characterized by being composed of the following components in parts by weight: 100 parts starch, 30 parts glycerol, 6 parts tea polyphenols, and 3 parts rod-shaped zinc oxide nanoparticles.
[0032] The preparation method includes the following steps:
[0033] (1) Add 100 parts starch and 30 parts glycerol to 1200 parts deionized water, stir for 30 minutes at room temperature, and then stir at 85°C to dissolve to obtain starch solution for later use;
[0034] (2) Disperse 6 parts of tea polyphenols in 800 parts of deionized water and stir for 1 hour to obtain a tea polyphenol solution for later use;
[0035] (3) Disperse 3 parts of rod-shaped zinc oxide nanoparticles in 800 parts of deionized water and stir for 1 hour to obtain a uniform dispersion for later use.
[0036] (4) Add the tea polyphenol solution obtained in step (2) and the rod-shaped zinc oxide nanoparticle dispersion obtained in step (3) to the starch solution obtained in step (1) and stir at 85°C for 1 hour to obtain a uniform film-forming liquid. Pour the film-forming liquid onto an organic glass dish and dry it in a vacuum oven at 50°C for 24 hours to obtain a thermoplastic starch-based nanocomposite material with excellent barrier properties.
[0037] Example 3
[0038] A thermoplastic starch-based nanocomposite material with excellent barrier properties is characterized by being composed of the following components in parts by weight: 100 parts starch, 30 parts glycerol, 6 parts tea polyphenols, and 5 parts rod-shaped zinc oxide nanoparticles.
[0039] The preparation method includes the following steps:
[0040] (1) Add 100 parts starch and 30 parts glycerol to 1200 parts deionized water, stir for 30 minutes at room temperature, and then stir at 85°C to dissolve to obtain starch solution for later use;
[0041] (2) Disperse 6 parts of tea polyphenols in 800 parts of deionized water and stir for 1 hour to obtain a tea polyphenol solution for later use;
[0042] (3) Disperse 5 parts of rod-shaped zinc oxide nanoparticles in 800 parts of deionized water and stir for 1 hour to obtain a uniform dispersion for later use.
[0043] (4) Add the tea polyphenol solution obtained in step (2) and the rod-shaped zinc oxide nanoparticle dispersion obtained in step (3) to the starch solution obtained in step (1) and stir at 85°C for 1 hour to obtain a uniform film-forming liquid. Pour the film-forming liquid onto an organic glass dish and dry it in a vacuum oven at 50°C for 24 hours to obtain a thermoplastic starch-based nanocomposite material with excellent barrier properties.
[0044] Example 4
[0045] A thermoplastic starch-based nanocomposite material with excellent barrier properties is characterized by being composed of the following components in parts by weight: 100 parts starch, 30 parts glycerol, 6 parts tea polyphenols, and 7 parts rod-shaped zinc oxide nanoparticles.
[0046] The preparation method includes the following steps:
[0047] (1) Add 100 parts starch and 30 parts glycerol to 1200 parts deionized water, stir for 30 minutes at room temperature, and then stir at 85°C to dissolve to obtain starch solution for later use;
[0048] (2) Disperse 6 parts of tea polyphenols in 800 parts of deionized water and stir for 1 hour to obtain a tea polyphenol solution for later use;
[0049] (3) Disperse 7 parts of rod-shaped zinc oxide nanoparticles in 800 parts of deionized water and stir for 1 hour to obtain a uniform dispersion for later use.
[0050] (4) Add the tea polyphenol solution obtained in step (2) and the rod-shaped zinc oxide nanoparticle dispersion obtained in step (3) to the starch solution obtained in step (1) and stir at 85°C for 1 hour to obtain a uniform film-forming liquid. Pour the film-forming liquid onto an organic glass dish and dry it in a vacuum oven at 50°C for 24 hours to obtain a thermoplastic starch-based nanocomposite material with excellent barrier properties.
[0051] Comparative Example 1
[0052] As a comparative standard for the above embodiments, the present invention provides a thermoplastic starch material prepared without tea polyphenols or rod-shaped zinc oxide nanoparticles, comprising the following steps:
[0053] (1) Add 100 parts starch and 30 parts glycerol to 1200 parts deionized water, stir for 30 minutes at room temperature, and then stir at 85°C to dissolve to obtain starch solution for later use;
[0054] (2) Add 1600 parts of deionized water to the starch solution obtained in step (1) and stir at 85°C for 1 hour to obtain a uniform film-forming solution.
[0055] (3) Pour the film-forming liquid from step (2) onto an organic glass dish and dry it in a vacuum oven at 50°C for 24 hours to obtain the thermoplastic starch material.
[0056] Structural and performance testing:
[0057] The thermoplastic starch materials prepared in the comparative examples and the thermoplastic starch-based nanocomposites prepared in the examples were subjected to performance tests. The tensile properties were tested according to GB / T1040-2006, the UV-Vis properties were tested using a UV spectrophotometer (TU-1901, Beijing Purkinje General Instrument Co., Ltd.), and the average transmittance of ultraviolet rays (UVA, UVB and UVC) was calculated with reference to GB / T18830-2009; the water vapor transmission coefficient was tested according to ASTM E96.
[0058] The hygroscopicity test method is as follows:
[0059] A membrane sample with dimensions of 20mm×20mm×0.1mm was placed in a vacuum drying oven at 105℃ and dried for 3 hours. The mass of the membrane sample was then weighed (denoted as M0). The dried membrane sample was then placed in a sealed container with a relative humidity of 57% and a temperature of 25℃ and left for 48 hours. The mass of the membrane sample was then weighed (denoted as M1). The moisture absorption rate (%) of the membrane sample was calculated as 100*(M1-M0) / M0.
[0060] The experimental method for DPPH free radical scavenging is as follows:
[0061] In the experimental group, 0.2g of membrane sample was cut into small pieces and soaked in 5mL of ethanol for 24 hours. Then, 2mL of the supernatant was extracted from the soaking solution for later use. Next, 1mL of 50mg / L DPPH solution was added to the 2mL supernatant, shaken well, and allowed to stand at room temperature in the dark for 1 hour. Finally, the absorbance of the mixture at 517nm (denoted as A) was measured using a UV spectrophotometer (Lambda 750, PerkinElmer Instruments). sample For the control group, 1 mL of 50 mg / L DPPH solution was added to 2 mL of ethanol, shaken well, and allowed to stand at room temperature in the dark for 1 hour. Then, the absorbance of the above mixture at 517 nm (denoted as A) was measured using a UV spectrophotometer (Lambda 750, PerkinElmer Instruments). control ); DPPH free radical scavenging rate (%) = 100 * (A control -A sample ) / A control .
[0062] The performance test data above are shown in Table 1.
[0063] Table 1 Performance test data of composite materials
[0064]
[0065] As can be seen from Table 1, the thermoplastic starch-based nanocomposite material prepared by this invention has excellent ultraviolet shielding performance, high-energy short-wave blue light blocking performance, mechanical properties, water vapor barrier performance, DPPH free radical scavenging activity (i.e. antioxidant activity) and low hygroscopicity. In addition, the preparation process of this composite film is simple, environmentally friendly, and low in cost, making it suitable for large-scale production and expanding the application field of thermoplastic starch-based composite materials.
[0066] The content of this invention is not limited to the embodiments listed. Any equivalent modifications made by those skilled in the art to the technical solutions of this invention by reading this specification are covered by the claims of this invention.
Claims
1. A thermoplastic starch-based nanocomposite material with high-energy short-wavelength blue light blocking properties, characterized in that, It is composed of the following components in parts by weight: 100 parts starch, 30 parts plasticizer, 6 parts tea polyphenols, and 5-7 parts rod-shaped zinc oxide nanoparticles; The starch mentioned is corn starch; The plasticizer is glycerin; The rod-shaped zinc oxide nanoparticles have a diameter of 50 nm and a length of 100–200 nm. The preparation method of the rod-shaped zinc oxide nanoparticles includes the following steps: dissolving zinc acetate dihydrate in 1,2-propanediol, then adding deionized water and stirring until homogeneous; adding sodium acetate to the above solution, stirring until homogeneous, heating to 150°C, and refluxing for 1 hour; then centrifuging and drying to obtain rod-shaped zinc oxide nanoparticles; The mass ratio of deionized water, zinc acetate dihydrate, sodium acetate, and 1,2-propanediol is 3.15:5.48:6.15:86.
3. The preparation method of the thermoplastic starch-based nanocomposite material with high-energy short-wavelength blue light blocking properties includes the following steps: (1) Add 100 parts of starch and 30 parts of plasticizer to 1200 parts of deionized water, stir for 30 minutes at room temperature, and then stir at 85°C to dissolve to obtain starch solution for later use; (2) Disperse 6 parts of tea polyphenols in 800 parts of deionized water and stir for 1 hour to obtain a tea polyphenol solution for later use; (3) Disperse 5-7 parts of rod-shaped zinc oxide nanoparticles in 800 parts of deionized water and stir for 1 hour to obtain a uniform dispersion for later use. (4) Add the tea polyphenol solution obtained in step (2) and the rod-shaped zinc oxide nanoparticle dispersion obtained in step (3) to the starch solution obtained in step (1) and stir at 85°C for 1 hour to obtain a uniform film-forming liquid. Pour the film-forming liquid onto an organic glass dish and dry it in a vacuum oven at 50°C for 24 hours to obtain a thermoplastic starch-based nanocomposite material with high-energy short-wave blue light blocking properties.