Reinforced and toughened cellulose acetate butyrate-based intelligent active film and application thereof

Abstract

The invention belongs to the technical field of polymer composite materials, and particularly relates to a reinforced and toughened cellulose acetate butyrate-based intelligent active film as well as a preparation method and application thereof, and the reinforced and toughened cellulose acetate butyrate-based intelligent active film is prepared from the following raw materials: cellulose acetate butyrate, glycerol and a functional reinforcing and toughening agent. The functional reinforcing and toughening agent is used for modifying the cellulose acetate butyrate membrane material, the mechanical strength, toughness and ductility of the membrane material are effectively improved, meanwhile, the ammonia response discoloration function, the antioxidant activity function, the ultraviolet blocking function and other functions of the membrane material are improved, and the membrane material is simple in preparation process and low in cost. The method has wide application value in the fields of food packaging, food freshness monitoring, ammonia gas detection, biomedicine, environment monitoring and safety and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of cellulose acetate butyrate-based composite materials, and specifically relates to a reinforced and toughened cellulose acetate butyrate-based intelligent active film and a preparation method and application thereof. Background Art

[0002] Cellulose acetate butyrate is a cellulose ester formed by the esterification of hydroxyl groups in cellulose molecules with acetic acid and butyric acid. It is a thermoplastic resin. As a common biodegradable material, cellulose acetate butyrate has good weather resistance and cold resistance, electrical insulation, easy processing and other characteristics. It also has excellent moisture resistance and transparency. It has broad application prospects in food packaging, biomedicine, plastics, coatings and other fields. However, the film material prepared from cellulose acetate butyrate has the disadvantages of low toughness, ductility and strength. At the same time, it lacks functions such as ammonia response color change, UV blocking, and antioxidant activity, which limits its application in the fields of smart active packaging.

[0003] Smart active packaging materials ensure food quality and safety by preventing food from spoiling during storage. On the other hand, smart active packaging materials are able to detect and report changes in food quality, freshness or safety throughout the storage period. Smart active packaging materials that integrate ammonia-sensitive color change and antioxidant activity functions provide an innovative dual-functional approach, which is essential for enhancing the safety of food during transportation, storage and use. Therefore, the development of new smart active packaging materials that integrate ammonia-sensitive color change and antioxidant activity functions has important practical significance and economic value for ensuring food quality and safety. The present invention uses cellulose acetate butyrate as a matrix and uses a functional reinforcing toughening agent as a filler to improve the mechanical strength, toughness, ductility, antioxidant activity, ammonia response color change and other properties of cellulose acetate butyrate materials, and develops a new type of strong and tough cellulose acetate butyrate-based smart active film that integrates ammonia-sensitive color change and antioxidant activity functions, so that it has a wider range of applications in food packaging, smart active materials, biomedicine, ammonia response materials, ammonia detection, environmental monitoring and safety and other fields. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing a reinforced and toughened cellulose acetate butyrate-based smart active membrane and its application. The smart active membrane material has excellent mechanical strength, toughness, tensile elongation at break (i.e., ductility), DPPH free radical scavenging activity (i.e., antioxidant activity), ammonia response color change and other properties, and can be used as a smart indicator material to timely and effectively indicate the freshness changes of meat foods such as shrimp during storage. The preparation process of the smart active membrane material is simple, environmentally friendly, low-cost, and suitable for scale-up production.

[0005] Technical solution of the present invention:

[0006] The present invention provides a reinforced and toughened cellulose acetate butyrate-based intelligent active film, characterized in that it is composed of the following components in parts by weight: 150 parts of cellulose acetate butyrate, 15 parts of glycerol, and 1.5-7.5 parts of a functional reinforcing and toughening agent;

[0007] The functional strengthening and toughening agent, the preparation method thereof comprises the following steps:

[0008] (1) dispersing 18.2 parts of 5-hydroxyisophthalic acid in 5000 parts of ethanol, stirring at room temperature for 30 minutes to obtain a uniform 5-hydroxyisophthalic acid dispersion for later use;

[0009] (2) taking 27.8 parts of ferrous sulfate heptahydrate, dissolving it in 500 parts of deionized water, stirring to obtain a uniform ferrous sulfate solution, and setting aside;

[0010] (3) adding the ferrous sulfate solution obtained in step (2) to the 5-hydroxyisophthalic acid dispersion obtained in step (1), stirring and reacting at room temperature for 30 minutes, and then centrifuging, washing, and drying in sequence to obtain a functional reinforcing and toughening agent.

[0011] The present invention also provides a method for preparing the above-mentioned enhanced and toughened cellulose acetate butyrate-based intelligent active film, which is characterized by comprising the following steps:

[0012] (1) adding 150 parts of cellulose acetate butyrate and 15 parts of glycerol to 2000 parts of ethanol, stirring at 55° C. for 20 minutes to obtain a uniform blend solution, cooling to room temperature, and setting aside;

[0013] (2) dispersing 1.5-7.5 parts of the functional reinforcing and toughening agent in 500 parts of ethanol, stirring at room temperature for 20 minutes to obtain a uniform dispersion for later use;

[0014] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), stirring at room temperature for 60 minutes to obtain a uniform film-forming solution for later use;

[0015] (4) The film-forming liquid obtained in step (3) is poured into a flat-bottomed glass dish and dried in an oven at 55° C. for 24 h to obtain a reinforced and toughened cellulose acetate butyrate-based smart active film.

[0016] The application of the cellulose acetate butyrate-based smart active film with enhanced toughness is characterized by being used in the fields of food packaging, food freshness monitoring, smart materials, biomedicine, ammonia responsive materials, ammonia detection, environmental monitoring and safety, etc.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The cellulose acetate butyrate-based smart active film prepared by the present invention has excellent mechanical strength, toughness, tensile elongation at break (i.e., ductility), ultraviolet blocking, DPPH free radical scavenging activity (i.e., antioxidant activity), ammonia response color change, biodegradability and other properties, while maintaining a relatively high visible light transparency, and can be used as a smart indicator material to timely and effectively indicate the freshness changes of meat foods (such as shrimp, pork, fish, etc.) during storage. The preparation process of the smart active film material is simple, environmentally friendly, low-cost, and suitable for scale-up production. It has wide application value in the fields of food packaging, food freshness monitoring, smart materials, biomedicine, ammonia response materials, ammonia detection, environmental monitoring and safety, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a scanning electron microscope image of the functional reinforcing and toughening agent involved in the present invention;

[0020] Figure 2 This is a scanning electron microscope image of a cross section of the cellulose acetate butyrate-based intelligent active membrane material prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0021] In order to better explain the present invention, the present invention is further explained in detail below in conjunction with specific examples, but the embodiments of the present invention are not limited thereto.

[0022] In the following specific embodiments and comparative example formulas and preparation methods, the cellulose acetate butyrate used is a product provided by Roan Reagent Co., Ltd. (article number: R096800-500g); propylene glycol (i.e., glycerol) used is an analytically pure reagent provided by Xilong Science Co., Ltd.; 5-hydroxyisophthalic acid is an analytically pure reagent provided by Aladdin Reagent Co., Ltd. (CAS number: 618-83-7); ferrous sulfate heptahydrate is an analytically pure reagent provided by Xilong Science Co., Ltd.; and ethanol is an analytically pure reagent provided by Tianjin Fuyu Fine Chemical Co., Ltd.

[0023] In the following specific examples and comparative examples, the formulations and preparation methods, the functional reinforcing and toughening agent is a nanocomplex prepared by reacting 5-hydroxyisophthalic acid with ferrous sulfate (the scanning electron microscope image of which is shown in Figure 1 ), the preparation method of which comprises the following steps:

[0024] (1) dispersing 18.2 parts of 5-hydroxyisophthalic acid in 5000 parts of ethanol, stirring at room temperature for 30 minutes to obtain a uniform 5-hydroxyisophthalic acid dispersion for later use;

[0025] (2) taking 27.8 parts of ferrous sulfate heptahydrate, dissolving it in 500 parts of deionized water to obtain a uniform ferrous sulfate solution for later use;

[0026] (3) adding the ferrous sulfate solution obtained in step (2) to the 5-hydroxyisophthalic acid dispersion obtained in step (1), stirring and reacting at room temperature for 30 minutes, and then centrifuging, washing, and drying in sequence to obtain a functional reinforcing and toughening agent.

[0027] Example 1

[0028] A reinforced and toughened cellulose acetate butyrate-based intelligent active film, characterized in that it is composed of the following components in parts by weight: 150 parts of cellulose acetate butyrate, 15 parts of glycerol, and 1.5 parts of a functional reinforcing and toughening agent.

[0029] The preparation method comprises the following steps:

[0030] (1) adding 150 parts of cellulose acetate butyrate and 15 parts of glycerol to 2000 parts of ethanol, stirring at 55° C. for 20 minutes to obtain a uniform blend solution, cooling to room temperature, and setting aside;

[0031] (2) dispersing 1.5 parts of the functional reinforcing and toughening agent in 500 parts of ethanol, stirring at room temperature for 20 minutes to obtain a uniform dispersion for later use;

[0032] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), stirring at room temperature for 60 minutes to obtain a uniform film-forming solution for later use;

[0033] (4) The film-forming liquid obtained in step (3) is poured into a flat-bottomed glass dish and dried in an oven at 55° C. for 24 h to obtain a reinforced and toughened cellulose acetate butyrate-based smart active film.

[0034] Example 2

[0035] A reinforced and toughened cellulose acetate butyrate-based intelligent active film, characterized in that it is composed of the following components in parts by weight: 150 parts of cellulose acetate butyrate, 15 parts of glycerol, and 4.5 parts of a functional reinforcing and toughening agent.

[0036] The preparation method comprises the following steps:

[0037] (1) adding 150 parts of cellulose acetate butyrate and 15 parts of glycerol to 2000 parts of ethanol, stirring at 55° C. for 20 minutes to obtain a uniform blend solution, cooling to room temperature, and setting aside;

[0038] (2) dispersing 4.5 parts of the functional reinforcing and toughening agent in 500 parts of ethanol, stirring at room temperature for 20 minutes to obtain a uniform dispersion for later use;

[0039] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), stirring at room temperature for 60 minutes to obtain a uniform film-forming solution for later use;

[0040] (4) The film-forming liquid obtained in step (3) is poured into a flat-bottomed glass dish and dried in an oven at 55° C. for 24 h to obtain a reinforced and toughened cellulose acetate butyrate-based smart active film.

[0041] Example 3

[0042] A reinforced and toughened cellulose acetate butyrate-based intelligent active film, characterized in that it is composed of the following components in parts by weight: 150 parts of cellulose acetate butyrate, 15 parts of glycerol, and 7.5 parts of a functional reinforcing and toughening agent.

[0043] The preparation method comprises the following steps:

[0044] (1) adding 150 parts of cellulose acetate butyrate and 15 parts of glycerol to 2000 parts of ethanol, stirring at 55° C. for 20 minutes to obtain a uniform blend solution, cooling to room temperature, and setting aside;

[0045] (2) dispersing 7.5 parts of the functional reinforcing and toughening agent in 500 parts of ethanol, stirring at room temperature for 20 minutes to obtain a uniform dispersion for later use;

[0046] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), stirring at room temperature for 60 minutes to obtain a uniform film-forming solution for later use;

[0047] (4) The film-forming liquid obtained in step (3) is poured into a flat-bottomed glass dish and dried in an oven at 55° C. for 24 h to obtain a reinforced and toughened cellulose acetate butyrate-based smart active film.

[0048] Comparative Example

[0049] As a comparison standard of the above embodiments, the present invention provides a cellulose acetate butyrate film material prepared without a functional reinforcing toughening agent, comprising the following steps:

[0050] (1) adding 150 parts of cellulose acetate butyrate and 15 parts of glycerol to 2000 parts of ethanol, stirring at 55° C. for 20 minutes to obtain a uniform blend solution, cooling to room temperature, and setting aside;

[0051] (2) adding 500 parts of ethanol to the blended solution obtained in step (1), stirring at room temperature for 60 minutes to obtain a uniform film-forming solution for later use;

[0052] (3) The film-forming solution obtained in step (2) is poured into a flat-bottomed glass dish and dried in an oven at 55° C. for 24 h to obtain a cellulose acetate butyrate film.

[0053] Structure and performance test:

[0054] The cellulose acetate butyrate film prepared in the above comparative example and the cellulose acetate butyrate-based smart active film prepared in the example were subjected to structure and performance tests, wherein the cross-sectional morphology of the cellulose acetate butyrate-based smart active film was characterized by a SEM (SU-5000, Japan Advanced Technology Corporation) instrument; the UV-visible performance was tested by a UV-visible spectrometer, 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 material was exposed to an ammonia environment, and the color change of the sample material was observed.

[0055] The DPPH free radical scavenging experimental method is as follows: 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 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. 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 by a UV spectrophotometer. control );DPPH free radical scavenging rate (%)=100*(A control -A sample ) / A control .

[0056] Shrimp freshness monitoring experiment: Fresh shrimps were purchased from the market, and the shrimps (mass: 30 g) were placed in a Petri dish and sealed with a Petri dish cover. The cellulose acetate butyrate film prepared in the comparative example and the cellulose acetate butyrate-based smart active film prepared in Example 3 (pre-cut into disc sample materials with a diameter of 1 cm) were attached to the bottom of the cover. The shrimp samples were then stored in an oven at 25°C, and the changes in the freshness of the shrimps and the color changes of the sample materials were observed and recorded.

[0057] The above performance test data are shown in Table 1 and Table 2.

[0058] Table 1 Sample performance test data

[0059]

[0060] Table 2 Results of shrimp freshness monitoring experiment (where t is the storage time of fresh shrimp)

[0061]

[0062] SEM results of cellulose acetate butyrate-based smart active membrane (see Figure 2 ) showed that the cross-sectional morphology was uniform, which meant that the functional reinforcing toughening agent had good compatibility with the acetate butyrate fiber matrix, which was conducive to obtaining an intelligent active membrane material with excellent performance.

[0063] The results of the ammonia response test experiment prove that the cellulose acetate butyrate film prepared in the comparative example is colorless and transparent. After being exposed to an ammonia environment, its color does not change, and it still exhibits colorless and transparent optical properties; the cellulose acetate butyrate-based intelligent active film prepared in Example 3 is yellow, and after being exposed to an ammonia environment, its color changes to brown.

[0064] The results of the DPPH free radical scavenging experiment show that the cellulose acetate butyrate-based intelligent active membrane material prepared in Example 3 has a DPPH free radical scavenging rate of 91.14%, indicating that it has excellent antioxidant activity, while the cellulose acetate butyrate membrane material prepared in the comparative example has no obvious antioxidant activity.

[0065] In summary, it can be seen from the sample performance test data (see Table 1) that the cellulose acetate butyrate-based intelligent active film material prepared by the present invention has excellent mechanical strength, toughness, tensile elongation at break (i.e., ductility), ammonia response color change, DPPH free radical scavenging rate (i.e., antioxidant activity), ultraviolet blocking and other properties, while maintaining a high visible light transparency. It can be used as an intelligent indicator material to timely and effectively indicate the freshness changes of meat foods such as shrimp during storage (see Table 2), and the preparation process of the film material is simple, environmentally friendly, low-cost, and suitable for large-scale production. It has wide application value in food packaging, food freshness monitoring, intelligent materials, biomedicine, ammonia detection, environmental monitoring and safety and other fields.

[0066] 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 reinforced and toughened cellulose acetate butyrate-based intelligent active membrane, characterized in that: The invention is composed of the following components in parts by weight: 150 parts of cellulose acetate butyrate, 15 parts of glycerol, and 1.5-7.5 parts of a functional reinforcing and toughening agent; The functional strengthening and toughening agent, the preparation method thereof comprises the following steps: (1) Disperse 18.2 parts of 5-hydroxyisophthalic acid in 5000 parts of ethanol, and stir at room temperature for 30 minutes to obtain a uniform 5-hydroxyisophthalic acid dispersion for later use; (2) Take 27.8 parts of ferrous sulfate heptahydrate and dissolve it in 500 parts of deionized water to obtain a uniform ferrous sulfate solution for later use; (3) Add the ferrous sulfate solution obtained in step (2) to the 5-hydroxyisophthalic acid dispersion obtained in step (1), stir and react at room temperature for 30 minutes, and then centrifuge, wash and dry in sequence to obtain a functional reinforcing and toughening agent.

2. The method for preparing a reinforced and toughened cellulose acetate butyrate-based smart active membrane according to claim 1, characterized in that The steps include: (1) Add 150 parts of cellulose acetate butyrate and 15 parts of glycerol to 2000 parts of ethanol, stir at 55°C for 20 minutes to obtain a uniform blend solution, cool to room temperature, and set aside; (2) Disperse 1.5-7.5 parts of the functional reinforcing and toughening agent in 500 parts of ethanol, stir at room temperature for 20 minutes to obtain a uniform dispersion for later use; (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), stirring at room temperature for 60 min to obtain a uniform film-forming solution for later use; (4) The film-forming liquid obtained in step (3) is poured into a flat-bottomed glass dish and dried in an oven at 55° C. for 24 h to obtain a reinforced and toughened cellulose acetate butyrate-based smart active membrane.

3. The use of a reinforced and toughened cellulose acetate butyrate-based smart active membrane according to claim 1, characterized in that: Used in food packaging, food freshness monitoring, and ammonia detection.

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