A strong and tough PBAT-based composite material with ammonia-sensitive color change function and a preparation method and application thereof

Abstract

The application belongs to the technical field of polymer composites, and particularly relates to a tough PBAT-based composite material with ammonia-sensitive color change function and a preparation method and application thereof. The composite material is prepared from the following raw materials: PBAT and functionalized starch nanocrystals. The application further provides a preparation method of the tough PBAT-based composite material. The prepared composite material has excellent mechanical strength, elongation at break, toughness, ultraviolet blocking, high-energy blue light blocking, ammonia gas response color change, biodegradability and other properties, and can maintain high visible light transparency. The composite material can be used as an intelligent indicating material, and has wide application value in the fields of food packaging, intelligent materials, biomedicine, ammonia gas detection, environmental monitoring and safety.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and particularly relates to a tough PBAT-based composite material with ammonia-sensitive color change function and a preparation method and application thereof. BACKGROUND

[0002] Traditional engineering plastics, such as polyethylene (PE), polypropylene (PP), polystyrene (PS) and the like, are difficult to degrade after being discarded, and will eventually become solid waste that pollutes soil and water. In addition, the depletion of fossil fuel resources increases people's interest in raw materials derived from renewable resources. Polybutylene adipate terephthalate (PBAT) belongs to typical petrochemical-based biodegradable plastics, and is one of the biodegradable plastics that are most researched and have the best application effect in the world. Although PBAT material already has good biodegradability, there is still much room for improvement in mechanical properties, strength, use performance, production cost and economic benefits, and some original shortcomings and disadvantages of PBAT material can be greatly improved and enhanced after modification. Starch nanocrystals are a kind of biobased nanomaterials derived from starch, and have the characteristics of green, edible, high specific surface area and high crystallinity, and are often used as “nanofillers” of biodegradable films. However, hydrophilic starch nanocrystals are difficult to effectively disperse in organic solvents (such as chloroform) and hydrophobic PBAT matrix, which is not conducive to the modification of starch nanocrystals to PBAT-based composite materials, thereby limiting the use of starch nanocrystals as “nanofillers” of PBAT material. The present application uses functionalized starch nanocrystals as functional fillers, which can be effectively dispersed in the hydrophobic PBAT matrix, so as to improve the mechanical strength, elongation at break, toughness, ultraviolet barrier, high-energy blue light barrier, ammonia gas response color change and other properties of PBAT material, develop a tough PBAT-based composite material with ammonia-sensitive color change function, and broaden its application in the fields of food packaging, intelligent materials, ammonia detection, environmental monitoring and safety. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art, and provides a tough PBAT-based composite material with ammonia-sensitive color change function and a preparation method and application thereof. The composite material has excellent mechanical strength, elongation at break, toughness, ultraviolet barrier, high-energy blue light barrier, ammonia gas response color change and other properties, and can also maintain high visible light transparency, can be used as an intelligent indicator material, and the preparation process of the composite material is simple, environmentally friendly, low in cost and suitable for large-scale production.

[0004] Technical scheme of the present application:

[0005] The application provides a tough PBAT-based composite material with ammonia-sensitive color change function, characterized by being composed of the following components in parts by weight: 100 parts of PBAT, 1-3 parts of functionalized starch nanocrystals;

[0006] The preparation method of the functionalized starch nanocrystals comprises the following steps:

[0007] (1) 200 parts of corn starch are added to 5000 parts of deionized water, stirred at 90 DEG C for 30 min to obtain a starch solution, then 5000 parts of ethanol is added, and stirring is continued at 90 DEG C for 75 min, and then cooled to room temperature, followed by centrifugal separation, ethanol washing and drying in sequence to obtain white starch nanocrystals for standby use;

[0008] (2) 40 parts of the starch nanocrystals obtained in step (1) are weighed and added to 3000 parts of ethanol, stirred at room temperature for 30 min to obtain a uniform starch nanocrystal dispersion liquid for standby use;

[0009] (3) 54 parts of ferric chloride hexahydrate are taken and dissolved in 1000 parts of methanol to obtain a uniform ferric chloride solution for standby use;

[0010] (4) The ferric chloride solution obtained in step (3) is added to the starch nanocrystal dispersion liquid obtained in step (2), and stirring is carried out at room temperature for 12 h to obtain a uniform blending liquid for standby use;

[0011] (5) 96.6 parts of 2-indolecarboxylic acid and 33.6 parts of potassium hydroxide are dissolved in 1500 parts of methanol to obtain a uniform blending liquid for standby use;

[0012] (6) The solution obtained in step (5) is added to the blending liquid obtained in step (4), and stirring is carried out at room temperature for 24 h, and then centrifugal separation, ethanol washing and drying are carried out in sequence to obtain the functionalized starch nanocrystals (the color of which is brownish).

[0013] The application further provides a preparation method of the tough PBAT-based composite material with ammonia-sensitive color change function, characterized by comprising the following steps:

[0014] (1) 1-3 parts of functionalized starch nanocrystals are added to 2000 parts of chloroform, ultrasonic treatment is carried out at room temperature for 30 min, and then stirring is carried out for 30 min to obtain a uniform dispersion liquid for standby use;

[0015] (2) 100 parts of PBAT is added to the dispersion liquid obtained in step (1), and stirring is carried out at room temperature for 2 h to obtain a uniform film-forming liquid for standby use;

[0016] (3) Pour the film-forming solution obtained in step (2) into a flat-bottomed glass dish, dry in an oven at 45 DEG C for 12 h, to obtain a tough PBAT-based composite material with ammonia-sensitive color change function.

[0017] The tough PBAT-based composite material with ammonia-sensitive color change function has the advantages of being used in the fields of food packaging, smart materials, ammonia detection, environmental monitoring and safety, etc.

[0018] Compared with the prior art, the present application has the beneficial effects of:

[0019] The functionalized starch nanocrystals are used as functional fillers, which can be effectively dispersed in the hydrophobic PBAT matrix to obtain a uniform and dense tough PBAT-based composite material; in addition, the tough PBAT-based composite material prepared by the present application has excellent mechanical strength, elongation at break, toughness, ultraviolet blocking, high-energy blue light blocking, ammonia-responsive color change, biodegradability and other properties, while maintaining high visible light transparency, and can be used as a smart indicator material, and the preparation process is simple, environmentally friendly, low in cost and suitable for large-scale production, and has wide application value in the fields of food packaging, smart materials, ammonia detection, environmental monitoring and safety, etc. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The scanning electron microscope images of the starch nanocrystals and the functionalized starch nanocrystals involved in the present application;

[0021] Figure 2 The Fourier infrared spectra of the starch nanocrystals and the functionalized starch nanocrystals involved in the present application;

[0022] Figure 3 The actual photo of the pure PBAT film sample prepared in the comparative example of the present application;

[0023] Figure 4 The actual photo of the tough PBAT-based composite film material sample prepared in Example 2 of the present application. DETAILED DESCRIPTION

[0024] The present application will be described in detail below by examples, and it is necessary to point out here that the examples are only used to further illustrate the present application and cannot be understood as limiting the scope of the present application, and those skilled in the art can make some non-essential improvements and adjustments according to the content of the present application, wherein the raw material parts are weight parts unless otherwise specified.

[0025] In the following specific examples and comparative example formula, preparation method, the PBAT is the product provided by Luo agent Co., Ltd.; Starch is corn starch provided by Aladdin biochemical technology Co., Ltd.; Ferric chloride hexahydrate is analytical reagent provided by Xilong Chemical Co., Ltd.; Potassium hydroxide is analytical reagent provided by Xilong Scientific Co., Ltd.; Methanol is analytical reagent provided by Xilong Scientific Co., Ltd.; 2-indole carboxylic acid is analytical reagent provided by Huawei Ruike Chemical Co., Ltd.; Anhydrous ethanol is analytical reagent provided by Tianjin Fuyu Fine Chemical Co., Ltd.

[0026] In the following specific examples and comparative example formula, preparation method, the functionalized starch nanocrystal, its preparation method includes the following steps:

[0027] (1) 200 parts of corn starch is added to 5000 parts of deionized water, stirred at 90℃ for 30 min to obtain a starch solution, then 5000 parts of ethanol is added, and the stirring is continued at 90℃ for 75 min. After cooling to room temperature, centrifugal separation, ethanol washing and drying are carried out in sequence to obtain white starch nanocrystals (the morphology is shown in the scanning electron microscope image in Figure 1 );

[0028] (2) 40 parts of the starch nanocrystals obtained in step (1) are weighed and added to 3000 parts of ethanol, stirred at room temperature for 30 min to obtain a uniform starch nanocrystal dispersion, which is ready for use;

[0029] (3) 54 parts of ferric chloride hexahydrate are taken and dissolved in 1000 parts of methanol to obtain a uniform ferric chloride solution, which is ready for use;

[0030] (4) The ferric chloride solution obtained in step (3) is added to the starch nanocrystal dispersion obtained in step (2), and stirred at room temperature for 12 h to obtain a uniform blending solution, which is ready for use;

[0031] (5) 96.6 parts of 2-indole carboxylic acid and 33.6 parts of potassium hydroxide are dissolved in 1500 parts of methanol to obtain a uniform blending solution, which is ready for use;

[0032] (6) The solution obtained in step (5) is added to the blending solution obtained in step (4), and stirred at room temperature for 24 h. After centrifugal separation, ethanol washing and drying in sequence, the functionalized starch nanocrystals are obtained (the color is brownish, and the morphology is shown in the scanning electron microscope image in Figure 1 ).

[0033] Example 1

[0034] A tough PBAT-based composite material with ammonia-sensitive color change function, characterized in that it is composed of the following components by weight: PBAT 100 parts, functionalized starch nanocrystals 1 part;

[0035] A preparation method, comprising the following steps:

[0036] (1) 1 part of functionalized starch nanocrystals is added to 2000 parts of chloroform, ultrasonic treatment at room temperature for 30 min, followed by stirring for 30 min to obtain a uniform dispersion solution, ready for use;

[0037] (2) 100 parts of PBAT is added to the dispersion solution obtained in step (1), stirring at room temperature for 2 h to obtain a uniform film-forming solution, ready for use;

[0038] (3) The film-forming solution obtained in step (2) is poured into a flat-bottomed glass dish, dried in an oven at 45°C for 12 h to obtain a tough PBAT-based composite material with ammonia-sensitive color change function.

[0039] Example 2

[0040] A tough PBAT-based composite material with ammonia-sensitive color change function, characterized in that it is composed of the following components by weight: PBAT 100 parts, functionalized starch nanocrystals 3 parts;

[0041] A preparation method, comprising the following steps:

[0042] (1) 3 parts of functionalized starch nanocrystals is added to 2000 parts of chloroform, ultrasonic treatment at room temperature for 30 min, followed by stirring for 30 min to obtain a uniform dispersion solution, ready for use;

[0043] (2) 100 parts of PBAT is added to the dispersion solution obtained in step (1), stirring at room temperature for 2 h to obtain a uniform film-forming solution, ready for use;

[0044] (3) The film-forming solution obtained in step (2) is poured into a flat-bottomed glass dish, dried in an oven at 45°C for 12 h to obtain a tough PBAT-based composite material with ammonia-sensitive color change function.

[0045] Comparative Example

[0046] As a comparison standard for the above examples, the present application provides a pure PBAT film material prepared without functionalized starch nanocrystals, comprising the following steps:

[0047] (1) 100 parts of PBAT is added to 2000 parts of chloroform, stirring at room temperature for 2 h to obtain a uniform film-forming solution, ready for use;

[0048] (2) Pour the film-forming solution obtained in step (1) into a flat-bottomed glass dish, and dry in an oven at 45℃ for 12 h to obtain a pure PBAT film material.

[0049] Structure and performance test:

[0050] The pure PBAT film material prepared by the above comparative example and the strong and tough PBAT-based composite material prepared by the examples are subjected to structure and performance test, wherein the ultraviolet-visible performance is tested by an ultraviolet-visible spectrometer (Lamdba365, PerkinElmer Instruments Co., Ltd.), and the average ultraviolet transmittance is calculated according to GB / T 18830-2009; the tensile performance is tested according to GB / T1040-2006; the ammonia response test method is as follows: the sample material is exposed to an ammonia environment, and the color change of the sample material is observed.

[0051] The performance test data are shown in Table 1.

[0052] Table 1: Performance test data of samples

[0053] Group Example 1 Example 2 Comparative Example Average UV transmittance (%) 0.15 0.04 0.25 Average high-energy blue light transmittance (%) 1.14 0.55 1.44 Tensile strength (MPa) 10.33 9.27 9.09 Elongation at break (%) 577.55 499.05 448.41 Toughness (MJ / m 3 ) 48.35 39.38 33.57

[0054] The ammonia response test results prove that the pure PBAT film material prepared by the comparative example is colorless and transparent, and its color does not change after being exposed to an ammonia environment, and still presents the colorless and transparent optical properties; the strong and tough PBAT-based composite material prepared by Example 1 is light brown, and its color changes to light yellow after being exposed to an ammonia environment; the PBAT-based nanocomposite material prepared by Example 2 is brown, and its color changes to yellow after being exposed to an ammonia environment.

[0055] In summary, the functionalized starch nanocrystals are used as functional fillers in the present application, which can be effectively dispersed in the hydrophobic PBAT matrix to obtain a uniform and dense strong and tough PBAT-based composite material; in addition, the strong and tough PBAT-based composite material prepared by the present application has excellent mechanical strength, elongation at break, toughness, ultraviolet barrier, high-energy blue light barrier, ammonia response color change, biodegradability and other properties, while still maintaining high visible light transparency, which can be used as an intelligent indicator material, and the preparation process of the composite material is simple, environmentally friendly, low in cost, suitable for large-scale production, and has wide application value in the fields of food packaging, intelligent materials, biomedicine, ammonia detection, environmental monitoring and safety.

[0056] The content of the present application is not limited to the examples listed, and any equivalent transformation of the technical solutions of the present application by a person of ordinary skill in the art by reading the specification of the present application is covered by the claims of the present application.

Claims

1. A strong and tough PBAT-based composite material with ammonia-sensitive color change function, characterized in that, Consist of the following components by weight: PBAT 100 parts, functionalized starch nanocrystals 1-3 parts; The preparation method of the functionalized starch nanocrystals comprises the following steps: (1) 200 parts of corn starch is added to 5000 parts of deionized water, stirred at 90°C for 30 min to obtain a starch solution, then 5000 parts of ethanol is added, and the stirring is continued at 90°C for 75 min, and then cooled to room temperature, followed by centrifugal separation, ethanol washing and drying in sequence to obtain white starch nanocrystals for standby use; (2) 40 parts of the starch nanocrystals obtained in step (1) is weighed and added to 3000 parts of ethanol, stirred at room temperature for 30 min to obtain a uniform starch nanocrystal dispersion liquid for standby use; (3) 54 parts of ferric chloride hexahydrate is taken and dissolved in 1000 parts of methanol to obtain a uniform ferric chloride solution for standby use; (4) the ferric chloride solution obtained in step (3) is added to the starch nanocrystal dispersion liquid obtained in step (2), stirred at room temperature for 12 h to obtain a uniform blending liquid for standby use; (5) 96.6 parts of 2-indolecarboxylic acid and 33.6 parts of potassium hydroxide are dissolved in 1500 parts of methanol to obtain a uniform blending liquid for standby use; (6) the solution obtained in step (5) is added to the blending liquid obtained in step (4), stirred at room temperature for 24 h, and then centrifugal separation, ethanol washing and drying in sequence to obtain the functionalized starch nanocrystals; The preparation method of the ammonia-sensitive color-changing functional tough PBAT-based composite material comprises the following steps: (1) 1-3 parts of functionalized starch nanocrystals is added to 2000 parts of chloroform, ultrasonically treated at room temperature for 30 min, and then stirred at room temperature for 30 min to obtain a uniform dispersion liquid for standby use; (2) 100 parts of PBAT is added to the dispersion liquid obtained in step (1), stirred at room temperature for 2 h to obtain a uniform film-forming liquid for standby use; (3) the film-forming liquid obtained in step (2) is poured into a flat-bottomed glass dish, dried in an oven at 45°C for 12 h to obtain the ammonia-sensitive color-changing functional tough PBAT-based composite material.

2. The method for preparing the strong and tough PBAT-based composite material with ammonia-sensitive color change function according to claim 1, characterized in that Comprise the following steps: (1) 1-3 parts of functionalized starch nanocrystals is added to 2000 parts of chloroform, ultrasonically treated at room temperature for 30 min, and then stirred at room temperature for 30 min to obtain a uniform dispersion liquid for standby use; (2) 100 parts of PBAT is added to the dispersion liquid obtained in step (1), stirred at room temperature for 2 h to obtain a uniform film-forming liquid for standby use; (3) the film-forming liquid obtained in step (2) is poured into a flat-bottomed glass dish, dried in an oven at 45°C for 12 h to obtain the ammonia-sensitive color-changing functional tough PBAT-based composite material.

3. Use of the strong and tough PBAT-based composite material with ammonia-sensitive color change function according to claim 1, characterized in that, For food packaging, smart materials, ammonia detection, environmental monitoring and safety fields.

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