Degradable preservation bag material and preparation method thereof
The spinning liquid is prepared by modifying the reaction of polycaprolactone with maleic anhydride and mixing it with chloroform, acetone and zinc nitrate, which solves the problem of poor mechanical strength of the degradable fresh-keeping bag material and achieves higher mechanical strength and antibacterial effects.
Patent Information
- Application Number
- CN202510373489.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-27
- Publication Date
- 2025-05-13
AI Technical Summary
It is not easy to degrade at this stage. Some degradable fresh-preserving bag materials have poor mechanical strength and are prone to damage during use.
The spinning liquid was prepared by mixing the modified additives, caprolactone, stannous octoate and N,N-dimethylformamide, pretreated polycaprolactone, then reacting with maleic anhydride, adding triethylamine and 4-dimethylaminopyridine, and finally mixing with chloroform, acetone and zinc nitrate to obtain a spinning liquid, and a degradable fresh-preserving bag material was made by blow-molding spinning.
It improves the mechanical strength of the biodegradable fresh-preserving bag material, reduces the risk of damage, and enhances the antibacterial effect and extends the fresh-preserving effect.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fresh-keeping bag preparation, and in particular to a degradable fresh-keeping bag material and a preparation method thereof. Background Art
[0002] Fresh-keeping bags refer to bags mainly used for preserving vegetables, fruits, grains, cooked food and other foods. They are widely used in daily life. Fresh-keeping bags are divided into polyethylene, polyvinyl chloride, polyvinylidene chloride and other types according to the materials they are made of. Antibacterial fresh-keeping bags refer to a kind of fresh-keeping bag that adds antibacterial agents to ordinary fresh-keeping bags, and achieves the purpose and function of antibacterial and fresh-keeping through the slow release and photocatalysis of antibacterial agents. It is mainly used for food preservation, antibacterial packaging, etc. However, conventional polymer materials such as polyethylene, polyvinyl chloride and polyvinylidene chloride have attracted widespread attention due to their long degradation cycle and potential harm to the environment. This not only increases the pressure on landfills, but may also cause pollution to soil and water sources. Therefore, it is particularly important to research and develop environmentally friendly degradable fresh-keeping bags. The main material of common degradable fresh-keeping bags is polylactic acid. Although polylactic acid fresh-keeping bags are degradable, the degradation rate is slow in industrial composting, and the mechanical strength of the prepared fresh-keeping bags is much lower than that of traditional materials, which affects the promotion of degradable fresh-keeping bags. Summary of the invention
[0003] The purpose of the present invention is to provide a degradable fresh-keeping bag material and a preparation method thereof, which solves the problem that the current degradable fresh-keeping bag material is not easy to degrade, has poor mechanical strength, and is easily damaged during use.
[0004] The purpose of the present invention can be achieved by the following technical solutions: A method for preparing a degradable fresh-keeping bag material comprises the following steps: Step A1: uniformly mix the modified additive, caprolactone, stannous octoate and N,N-dimethylformamide, introduce nitrogen protection, and react for 20-24 hours at a speed of 120-150 r / min and a temperature of 120-130° C. to obtain pretreated polycaprolactone; Step A2: pretreated polycaprolactone, maleic anhydride and N,N-dimethylformamide are uniformly mixed, and triethylamine and 4-dimethylaminopyridine are added under stirring at a speed of 150-200 r / min and a temperature of 30-40° C. to react for 20-25 hours to obtain modified polycaprolactone; Step A3: The modified polycaprolactone, chloroform, acetone and zinc nitrate are mixed evenly to prepare a spinning solution, and blow-spinning is performed under the conditions of an injection pump flow rate of 1.2-1.5 mL / h, a gas pressure of 0.3-0.5 MPa and a receiving distance of 20 cm to prepare a degradable fresh-keeping bag material.
[0005] Furthermore, the mass ratio of the modifying additive, caprolactone and stannous octoate described in step A1 is 5:100:1.
[0006] Furthermore, the amount ratio of the pretreated polycaprolactone, maleic anhydride, triethylamine and 4-dimethylaminopyridine in step A2 is 1 g: 1.1 mmol: 1 mmol: 1.1 mmol.
[0007] Furthermore, the weight ratio of the modified polycaprolactone, chloroform, acetone and zinc nitrate described in step A3 is 8-15:60-70:30-40:0.5-0.7.
[0008] Further, the modified additive is prepared by the following steps: Step B1: bamboo fiber, sodium hydroxide and deionized water are mixed, and the mixture is kept warm for 2-3 hours at a speed of 200-300 r / min and a temperature of 100-105° C., and the filtrate is removed by filtering, and the substrate, lithium chloride and N,N-dimethylacetamide are mixed, and the mixture is kept warm for 20-25 hours at a speed of 30-60 r / min and a temperature of 25-30° C., and acryloyl chloride and pyridine are added, and the mixture is heated to 50-60° C. and reacted for 15-20 hours to obtain functionalized bamboo fiber; Step B2: 3-mercapto-1,2-propanediol, 4-hydroxyphenylboric acid and tetrahydrofuran are mixed evenly, and reacted for 3-5 hours at a speed of 150-200 r / min, a temperature of 70-80° C. and a pH value of 5-6 to obtain a modifier; the modifier, functionalized bamboo fiber, benzophenone and tetrahydrofuran are mixed evenly, and reacted for 5-10 minutes at a speed of 60-80 r / min and 365 nm ultraviolet light irradiation to obtain modified bamboo fiber; Step B3: uniformly mix the modified cellulose, propylene oxide, potassium hydroxide and N,N-dimethylformamide, react for 1-1.5 hours at a speed of 120-150 r / min and a temperature of 80-90° C., then cool to 40-50° C., continue the reaction for 3-4 hours, adjust the pH value to neutral, and obtain a modified additive.
[0009] Furthermore, the amount ratio of the bamboo fiber, sodium hydroxide, deionized water, lithium chloride, N,N-dimethylacetamide solution, acryloyl chloride and pyridine in step B1 is 1g:2g:20mL:1g:12mL:5g:4.3g.
[0010] Furthermore, the molar ratio of 3-mercapto-1,2-propanediol and 4-hydroxyphenylboronic acid in step B2 is 1:1, the molar ratio of the modifier to the double bonds on the functionalized bamboo fiber is 1:1, and the amount of benzophenone is 1‰ of the mass of the modifier.
[0011] Furthermore, the mass ratio of the modified cellulose and glycidol in step B3 is 1:15, and the amount of potassium hydroxide used is 3‰ of the mass of glycidol.
[0012] The beneficial effects of the present invention are as follows: a degradable fresh-keeping bag material comprises the following raw materials: modified polycaprolactone, chloroform, acetone and zinc nitrate, the raw materials are uniformly mixed, blow-molded and spun to obtain the degradable fresh-keeping bag material, the modified polycaprolactone takes a modified additive and caprolactone as raw materials, under the action of stannous octoate, forms polycaprolactone chain segments with active hydroxyl groups on the modified additive molecules as endpoints to obtain pretreated polycaprolactone, the pretreated polycaprolactone is reacted with maleic anhydride, the maleic anhydride is ring-opened and esterified with active hydroxyl groups and carboxyl groups on the pretreated polycaprolactone, and active carboxyl groups are grafted on the molecular chain to obtain the modified polycaprolactone.
[0013] The modified additive uses bamboo fiber as a raw material, is treated with sodium hydroxide alkali, then activated with lithium chloride, and finally reacted with acryloyl chloride, so that the active hydroxyl on the bamboo fiber reacts with the acyl chloride on the acryloyl chloride to obtain functionalized bamboo fiber, 3-mercapto-1,2-propylene glycol and 4-hydroxyphenylboronic acid are reacted, so that the diol on the 3-mercapto-1,2-propylene glycol and the boric acid group on the 4-hydroxyphenylboronic acid react to form borate ester to obtain a modifier, the modifier and the functionalized bamboo fiber are reacted under ultraviolet light, so that the thiol on the modifier reacts with the double bond on the functionalized bamboo fiber to obtain modified bamboo fiber, the modified bamboo fiber and glycidol are reacted under the action of potassium hydroxide, so that the epoxide on the glycidol reacts with the active hydroxyl on the modified bamboo fiber, and the remaining glycidol forms a polyether polyol to obtain a modified additive.
[0014] When modified polycaprolactone, chloroform, acetone and zinc nitrate are mixed, the active carboxyl groups in the modified polycaprolactone react with the zinc ions produced by the zinc nitrate to form zinc carboxylates and zincates, which can increase the antibacterial effect of the cling film and reduce the internal stress concentration points, thereby reducing the potential starting points of fracture of the cling film when subjected to external forces, thereby improving the tensile strength of the cling film. In addition, bamboo fibers containing long-chain polyether polyols serve as the reaction endpoints of polycaprolactone to form a diffuse molecular chain network containing borate esters, further improving the mechanical strength of the cling film. DETAILED DESCRIPTION
[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0016] Embodiment 1, a method for preparing a degradable fresh-keeping bag material, specifically comprising the following steps: Step A1: uniformly mixing the modifying additive, caprolactone, stannous octoate and N,N-dimethylformamide, introducing nitrogen protection, and reacting for 20 hours at a speed of 120 r / min and a temperature of 120° C. to obtain pretreated polycaprolactone; Step A2: pretreated polycaprolactone, maleic anhydride and N,N-dimethylformamide were uniformly mixed, and triethylamine and 4-dimethylaminopyridine were added under stirring at a speed of 150 r / min and a temperature of 30° C., and the mixture was reacted for 20 hours to obtain modified polycaprolactone; Step A3: The modified polycaprolactone, chloroform, acetone and zinc nitrate are mixed evenly to prepare a spinning solution, and blow-spinning is performed under the conditions of an injection pump flow rate of 1.2 mL / h, a gas pressure of 0.3 MPa, and a receiving distance of 20 cm to prepare a degradable fresh-keeping bag material.
[0017] The mass ratio of the modifying additive, caprolactone and stannous octoate described in step A1 is 5:100:1.
[0018] The amount ratio of the pretreated polycaprolactone, maleic anhydride, triethylamine and 4-dimethylaminopyridine described in step A2 is 1 g: 1.1 mmol: 1 mmol: 1.1 mmol.
[0019] The weight ratio of the modified polycaprolactone, chloroform, acetone and zinc nitrate described in step A3 is 8:60:30:0.5.
[0020] The modified additive is prepared by the following steps: Step B1: bamboo fiber, sodium hydroxide and deionized water are mixed, and the mixture is kept warm for 2 hours at a speed of 200 r / min and a temperature of 100° C., and the filtrate is removed by filtration, and the substrate, lithium chloride and N,N-dimethylacetamide are mixed, and the mixture is kept warm for 20 hours at a speed of 30 r / min and a temperature of 25° C., and acryloyl chloride and pyridine are added, and the mixture is heated to 50° C. and reacted for 15 hours to obtain functionalized bamboo fiber; Step B2: 3-mercapto-1,2-propanediol, 4-hydroxyphenylboric acid and tetrahydrofuran were mixed evenly, and reacted for 3 hours at a speed of 150 r / min, a temperature of 70° C. and a pH value of 5 to obtain a modifier; the modifier, functionalized bamboo fiber, benzophenone and tetrahydrofuran were mixed evenly, and reacted for 5 minutes at a speed of 60 r / min and 365 nm ultraviolet light irradiation to obtain modified bamboo fiber; Step B3: uniformly mix the modified cellulose, propylene oxide, potassium hydroxide and N,N-dimethylformamide, react at a speed of 120 r / min and a temperature of 80° C. for 1 hour, then cool to 40° C. and continue the reaction for 3 hours. Adjust the pH value to neutral to obtain a modified additive.
[0021] The amount ratio of the bamboo fiber, sodium hydroxide, deionized water, lithium chloride, N,N-dimethylacetamide solution, acryloyl chloride and pyridine described in step B1 is 1g:2g:20mL:1g:12mL:5g:4.3g.
[0022] The molar ratio of 3-mercapto-1,2-propanediol and 4-hydroxyphenylboronic acid in step B2 is 1:1, the molar ratio of the modifier to the double bonds on the functionalized bamboo fiber is 1:1, and the amount of benzophenone used is 1‰ of the mass of the modifier.
[0023] The mass ratio of the modified cellulose to glycidol in step B3 is 1:15, and the amount of potassium hydroxide used is 3‰ of the mass of glycidol.
[0024] Embodiment 2, a method for preparing a degradable fresh-keeping bag material, specifically comprising the following steps: Step A1: uniformly mixing the modifying additive, caprolactone, stannous octoate and N,N-dimethylformamide, introducing nitrogen protection, and reacting for 22 hours at a speed of 120 r / min and a temperature of 125° C. to obtain pretreated polycaprolactone; Step A2: pretreated polycaprolactone, maleic anhydride and N,N-dimethylformamide were uniformly mixed, and triethylamine and 4-dimethylaminopyridine were added under stirring at a speed of 150 r / min and a temperature of 35° C., and the mixture was reacted for 25 hours to obtain modified polycaprolactone; Step A3: The modified polycaprolactone, chloroform, acetone and zinc nitrate are mixed evenly to prepare a spinning solution, and blow-spinning is performed under the conditions of an injection pump flow rate of 1.2 mL / h, a gas pressure of 0.5 MPa, and a receiving distance of 20 cm to prepare a degradable fresh-keeping bag material.
[0025] The mass ratio of the modifying additive, caprolactone and stannous octoate described in step A1 is 5:100:1.
[0026] The amount ratio of the pretreated polycaprolactone, maleic anhydride, triethylamine and 4-dimethylaminopyridine described in step A2 is 1 g: 1.1 mmol: 1 mmol: 1.1 mmol.
[0027] The weight ratio of the modified polycaprolactone, chloroform, acetone and zinc nitrate described in step A3 is 11:65:35:0.6.
[0028] The modified additive is prepared by the following steps: Step B1: bamboo fiber, sodium hydroxide and deionized water are mixed, and the mixture is kept warm for 3 hours at a speed of 200 r / min and a temperature of 100° C., and the filtrate is removed by filtration, and the substrate, lithium chloride and N,N-dimethylacetamide are mixed, and the mixture is kept warm for 20 hours at a speed of 30 r / min and a temperature of 30° C., and acryloyl chloride and pyridine are added, and the mixture is heated to 55° C. and reacted for 20 hours to obtain functionalized bamboo fiber; Step B2: 3-mercapto-1,2-propanediol, 4-hydroxyphenylboric acid and tetrahydrofuran were mixed evenly, and reacted for 4 hours at a speed of 150 r / min, a temperature of 75° C. and a pH value of 5 to obtain a modifier; the modifier, functionalized bamboo fiber, benzophenone and tetrahydrofuran were mixed evenly, and reacted for 8 minutes at a speed of 80 r / min and irradiated with 365 nm ultraviolet light to obtain modified bamboo fiber; Step B3: Evenly mix the modified cellulose, propylene oxide, potassium hydroxide and N,N-dimethylformamide, react for 1.5 hours at a speed of 120 r / min and a temperature of 85°C, then cool to 45°C, continue the reaction for 4 hours, adjust the pH value to neutral, and obtain a modified additive.
[0029] The amount ratio of the bamboo fiber, sodium hydroxide, deionized water, lithium chloride, N,N-dimethylacetamide solution, acryloyl chloride and pyridine described in step B1 is 1g:2g:20mL:1g:12mL:5g:4.3g.
[0030] The molar ratio of 3-mercapto-1,2-propanediol and 4-hydroxyphenylboronic acid in step B2 is 1:1, the molar ratio of the modifier to the double bonds on the functionalized bamboo fiber is 1:1, and the amount of benzophenone used is 1‰ of the mass of the modifier.
[0031] The mass ratio of the modified cellulose to glycidol in step B3 is 1:15, and the amount of potassium hydroxide used is 3‰ of the mass of glycidol.
[0032] Embodiment 3, a method for preparing a degradable fresh-keeping bag material, specifically comprising the following steps: Step A1: uniformly mixing the modifying additive, caprolactone, stannous octoate and N,N-dimethylformamide, introducing nitrogen protection, and reacting for 24 hours at a speed of 150 r / min and a temperature of 130° C. to obtain pretreated polycaprolactone; Step A2: pretreated polycaprolactone, maleic anhydride and N,N-dimethylformamide were uniformly mixed, and triethylamine and 4-dimethylaminopyridine were added under stirring at a speed of 200 r / min and a temperature of 40° C., and the mixture was reacted for 25 hours to obtain modified polycaprolactone; Step A3: The modified polycaprolactone, chloroform, acetone and zinc nitrate are mixed evenly to prepare a spinning solution, and blow-spinning is performed under the conditions of an injection pump flow rate of 1.5 mL / h, a gas pressure of 0.5 MPa, and a receiving distance of 20 cm to prepare a degradable fresh-keeping bag material.
[0033] The mass ratio of the modifying additive, caprolactone and stannous octoate described in step A1 is 5:100:1.
[0034] The amount ratio of the pretreated polycaprolactone, maleic anhydride, triethylamine and 4-dimethylaminopyridine described in step A2 is 1 g: 1.1 mmol: 1 mmol: 1.1 mmol.
[0035] The weight ratio of the modified polycaprolactone, chloroform, acetone and zinc nitrate described in step A3 is 15:70:40:0.7.
[0036] The modified additive is prepared by the following steps: Step B1: bamboo fiber, sodium hydroxide and deionized water are mixed, and the mixture is kept warm for 3 hours at a speed of 300 r / min and a temperature of 105° C., and the filtrate is removed by filtration, and the substrate, lithium chloride and N,N-dimethylacetamide are mixed, and the mixture is kept warm for 25 hours at a speed of 60 r / min and a temperature of 30° C., and acryloyl chloride and pyridine are added, and the mixture is heated to 60° C. and reacted for 20 hours to obtain functionalized bamboo fiber; Step B2: 3-mercapto-1,2-propanediol, 4-hydroxyphenylboric acid and tetrahydrofuran were mixed evenly, and reacted for 5 hours at a speed of 200 r / min, a temperature of 80° C. and a pH value of 6 to obtain a modifier; the modifier, functionalized bamboo fiber, benzophenone and tetrahydrofuran were mixed evenly, and reacted for 10 minutes at a speed of 80 r / min and 365 nm ultraviolet light irradiation to obtain modified bamboo fiber; Step B3: Evenly mix the modified cellulose, propylene oxide, potassium hydroxide and N,N-dimethylformamide, react for 1.5 hours at a speed of 150 r / min and a temperature of 90° C., then cool to 50° C., continue the reaction for 4 hours, adjust the pH value to neutral, and obtain a modified additive.
[0037] The amount ratio of the bamboo fiber, sodium hydroxide, deionized water, lithium chloride, N,N-dimethylacetamide solution, acryloyl chloride and pyridine described in step B1 is 1g:2g:20mL:1g:12mL:5g:4.3g.
[0038] The molar ratio of 3-mercapto-1,2-propanediol and 4-hydroxyphenylboronic acid in step B2 is 1:1, the molar ratio of the modifier to the double bonds on the functionalized bamboo fiber is 1:1, and the amount of benzophenone used is 1‰ of the mass of the modifier.
[0039] The mass ratio of the modified cellulose to glycidol in step B3 is 1:15, and the amount of potassium hydroxide used is 3‰ of the mass of glycidol.
[0040] Comparative Example 1: Compared with Example 1, pretreated polycaprolactone is used instead of modified polycaprolactone, and the remaining steps are the same.
[0041] Comparative Example 2: Compared with Example 1, 4-mercaptophenol was used to replace the modifier, and the remaining steps were the same.
[0042] Comparative Example 3: Compared with Example 1, pentaerythritol is used to replace the modified cellulose, and the other steps are the same.
[0043] The cling film obtained in Examples 1-3 and Comparative Examples 1-3 was made into samples of 50×10×0.03 mm, and the tensile properties were tested according to the standard of GB / T1040.3-2006, and the tear strength was tested according to the standard of GB / T16578.1-2008. The test results are shown in Table 1 below.
[0044]
[0045] It can be seen from Table 1 that the present invention has good mechanical properties.
[0046] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.
Claims
1. A method for preparing a degradable fresh-keeping bag material, characterized in that: The specific steps include: Step A1: uniformly mixing the modification additive, caprolactone, stannous octoate and N,N-dimethylformamide, introducing nitrogen gas for protection, and reacting to obtain pretreated polycaprolactone; Step A2: pretreated polycaprolactone, maleic anhydride and N,N-dimethylformamide are mixed and stirred, and triethylamine and 4-dimethylaminopyridine are added to react to obtain modified polycaprolactone; Step A3: uniformly mix the modified polycaprolactone, chloroform, acetone and zinc nitrate to obtain a spinning solution, and blow-spin the spinning solution to obtain a degradable fresh-keeping bag material.
2. The method for preparing a degradable fresh-keeping bag material according to claim 1, characterized in that: The mass ratio of the modifying additive, caprolactone and stannous octoate described in step A1 is 5:100:
1.
3. The method for preparing a degradable fresh-keeping bag material according to claim 1, characterized in that: The weight ratio of the modified polycaprolactone, chloroform, acetone and zinc nitrate in step A3 is 8-15:60-70:30-40:0.5-0.
7.
4. The method for preparing a degradable fresh-keeping bag material according to claim 1, characterized in that: The modified additive is prepared by the following steps: Step B1: mixing bamboo fiber, sodium hydroxide and deionized water, heating and preserving the mixture, filtering and removing the filtrate, mixing the substrate, lithium chloride and N,N-dimethylacetamide, heating and preserving the mixture, adding acryloyl chloride and pyridine, reacting the mixture, and obtaining functionalized bamboo fiber; Step B2: 3-mercapto-1,2-propylene glycol, 4-hydroxyphenylboronic acid and tetrahydrofuran are mixed and reacted to obtain a modifier, and the modifier, functionalized bamboo fiber, benzophenone and tetrahydrofuran are mixed and reacted to obtain modified bamboo fiber; Step B3: Mix the modified cellulose, propylene oxide, potassium hydroxide and N,N-dimethylformamide for reaction, and adjust the pH value to be neutral to obtain a modified additive.
5. The method for preparing a degradable fresh-keeping bag material according to claim 4, characterized in that: The amount ratio of the bamboo fiber, sodium hydroxide, deionized water, lithium chloride, N,N-dimethylacetamide solution, acryloyl chloride and pyridine described in step B1 is 1g:2g:20mL:1g:12mL:5g:4.3g.
6. The method for preparing a degradable fresh-keeping bag material according to claim 4, characterized in that: The molar ratio of 3-mercapto-1,2-propanediol and 4-hydroxyphenylboronic acid in step B2 is 1:1, the molar ratio of the modifier to the double bonds on the functionalized bamboo fiber is 1:1, and the amount of benzophenone used is 1‰ of the mass of the modifier.
7. The method for preparing a degradable fresh-keeping bag material according to claim 4, characterized in that: The mass ratio of the modified cellulose to glycidol in step B3 is 1:15, and the amount of potassium hydroxide used is 3‰ of the mass of glycidol.
8. A degradable fresh-keeping bag material, characterized by: Prepared according to any one of claims 1 to 7.