Degradable medical packaging box material and preparation method thereof

Abstract

The invention relates to the field of packaging box materials, and particularly discloses a degradable medical packaging box material and a preparation method thereof. Comprising the following raw materials in parts by weight: 20-30 parts of polymethyl ethylene carbonate, 30-40 parts of polylactic acid, 3-5 parts of a plasticizer, 1-3 parts of an antioxidant, 5-8 parts of a reinforcing filler and 5-10 parts of carboxymethyl chitosan. The reinforcing filler is a compound of nano silicon dioxide and jute fibers; according to the degradable medical packaging box material prepared by the invention, the polymethyl ethylene carbonate is combined with the polylactic acid, and the nano silicon dioxide and the jute fibers are used for synergistic interaction, so that the thermal stability and the impact strength of the packaging box material are improved, and the thermal processing stability of the packaging box material is enhanced.

Description

Technical Field

[0001] This application relates to the field of packaging box materials, and particularly to a degradable medical packaging box material and its preparation method. Background Art

[0002] Medical packaging box materials play a crucial role in the modern medical field. Their main function is to protect medical devices and drugs from the external environment, ensuring their safety and effectiveness during transportation and storage. With the improvement of environmental awareness and the emphasis on sustainable development, the use of degradable materials in the field of medical packaging boxes can not only meet the high-performance requirements of the medical industry for packaging materials but also effectively reduce the pollution caused by plastic waste to the environment.

[0003] However, the current biodegradable materials mainly include starch, polylactic acid, and biodegradable polyesters. Starch has been deeply studied due to its low price and wide sources, and various household and industrial products have been prepared through modification and compounding. However, starch has natural defects. Its mechanical properties are poor and its performance is unstable, so it can only be used in fields with low requirements for mechanical properties. Polylactic acid (PLA) is a green and environmentally friendly bio-based material with good biocompatibility, biodegradability, and mechanical strength. However, polylactic acid has the obvious disadvantage of insufficient flexibility, and its elongation at break and thermal stability are significantly insufficient, which further limits its application. Summary of the Invention

[0004] In order to improve the deficiencies of existing degradable packaging materials, this application provides a degradable medical packaging box material and its preparation method.

[0005] In the first aspect, this application provides a degradable medical packaging box material, adopting the following technical scheme: A degradable medical packaging box material, comprising the following raw materials in parts by weight: 20 - 30 parts of poly(methyl ethylene carbonate), 30 - 40 parts of polylactic acid, 3 - 5 parts of plasticizer, 1 - 3 parts of antioxidant, 5 - 8 parts of reinforcing filler, and 5 - 10 parts of carboxymethyl chitosan; the reinforcing filler is a composite of nano-silica and jute fiber.

[0006] By adopting the above technical scheme, the combination of poly(methyl ethylene carbonate) and polylactic acid can utilize the carbonate bonds in the main chain of poly(methyl ethylene carbonate) to absorb external impacts, reduce the rupture of the packaging box, and improve the flexibility of the packaging box material. Carboxymethyl chitosan can endow the packaging box material with good antibacterial effects. The synergistic effect of using nano-silica and jute fiber can form a rigid network in the packaging box material system, improve the thermal stability and impact strength of the packaging box material, and enhance the thermal processing stability of the packaging box material.

[0007] Preferably, the nano-silica is pre-grafted with jute fiber.

[0008] By adopting the above technical solution, nano-silica can fill the pores of fibers. The nano-silica and jute fibers are grafted to form a reinforcing framework in the packaging material system, improving the tensile strength and impact strength of the packaging box material. At the same time, nano-silica can improve the interfacial interaction between jute fibers and polylactic acid and poly(ethylene carbonate), enhancing the overall tensile strength and toughness of the packaging box material.

[0009] Preferably, the grafting method includes the following specific steps: First, pretreat the jute fibers with alkali. After drying the nano-silica, mix it evenly with a grafting assistant and a solvent to form a nano-silica mixed solution. Then, add a catalyst to the nano-silica mixed solution, heat and react, and perform centrifugal separation. After drying the grafted nano-silica, mix it with the alkali-treated jute fibers to form a composite solution. Add a solvent and a catalyst to the composite solution, heat and catalyze the reaction, perform centrifugal separation, and obtain a nano-silica-jute fiber grafted composite after drying.

[0010] By adopting the above technical solution, the nano-silica is pre-activated on the surface with a grafting assistant, which can combine the hydroxyl groups on the surface of the silica with the grafting assistant. Then, the silica is grafted to the jute fibers with the grafting assistant as a bridge, forming a nano-silica-jute fiber grafted composite with a high thermal decomposition temperature and enhancing the heat resistance of the packaging box material.

[0011] Preferably, the heating reaction temperature is 90 - 100 °C, and the heating catalytic reaction temperature is 90 - 100 °C.

[0012] Preferably, the nano-silica-jute fiber grafted composite comprises the following raw materials in parts by weight: 8 - 13 parts of nano-silica, 10 - 15 parts of jute fibers, 0.5 - 1 part of catalyst, 40 - 60 parts of solvent, and 5 - 15 parts of grafting assistant.

[0013] Preferably, the grafting assistant is toluene diisocyanate.

[0014] By adopting the above technical solution, toluene diisocyanate has high activity, can undergo a grafting reaction with the surface of silica, and can also react with the hydroxyl groups on the surface of jute fibers, enhancing the compatibility of silica, jute fibers and the polymer matrix, and improving the overall tensile strength and impact strength of the packaging film material.

[0015] Preferably, the poly(ethylene carbonate) is pre-mixed with wood powder and a coupling agent, and the mass ratio of the poly(ethylene carbonate) to the wood powder and the coupling agent is 1:(0.2 - 0.4):(0.2 - 0.4).

[0016] By adopting the above technical solution, coupling agent is used to link wood powder to the surface of poly(ethylene carbonate) in advance, which can improve the thermal stability and flexural strength of poly(ethylene carbonate), reduce the phenomenon of thermal degradation during the processing of poly(ethylene carbonate), and enhance the thermal stability and strength of the packaging material.

[0017] In a second aspect, the present application provides a preparation method for a degradable medical packaging box material, adopting the following technical solution: A preparation method for a degradable medical packaging box material includes the following specific steps: Mix poly(ethylene carbonate), polylactic acid, plasticizer, antioxidant and reinforcing filler evenly, heat and melt them, and extrude to obtain the degradable medical packaging box material.

[0018] By adopting the above technical solution, through the synergistic effect of each component, the flexibility, impact strength and thermal stability of the packaging box material can be improved, and the thermal processing stability of the packaging box material can be enhanced.

[0019] Preferably, mix poly(ethylene carbonate) and wood powder evenly at 110 - 120 °C, then add coupling agent and mix, and cool to obtain poly(ethylene carbonate)-wood powder composite; Mix poly(ethylene carbonate)-wood powder composite, polylactic acid, plasticizer, antioxidant and reinforcing filler evenly, heat and melt them, and extrude to obtain the degradable medical packaging box material.

[0020] Preferably, the heating and melting temperature is 150 - 170 °C.

[0021] In summary, the present application has the following beneficial effects: 1. Since the present application combines poly(ethylene carbonate) and polylactic acid, it improves the problem of insufficient flexibility of single polylactic acid. Using nano-silica and jute fiber synergistically, it improves the thermal stability and impact strength of the packaging box material, and enhances the thermal processing stability of the packaging box material.

[0022] 2. In the present application, nano-silica is grafted onto the surface of jute fiber through toluene diisocyanate as a bridge, which promotes good compatibility and binding effect between nano-silica, jute fiber and polymer matrix, and improves the tensile strength, impact strength and thermal stability of the overall packaging film material. Detailed Embodiments

[0023] The following further elaborates the present application in detail with reference to examples.

[0024] All raw materials in the examples can be obtained commercially. Examples

[0025] Example 1 This embodiment provides a degradable medical packaging box material, which comprises the following raw materials in parts by weight: 25 kg of poly(ethylene carbonate), 35 kg of polylactic acid, 4 kg of plasticizer, 2 kg of antioxidant, 7 kg of reinforcing filler, and 8 kg of carboxymethyl chitosan. Among them, the number-average molecular weight of poly(ethylene carbonate) is 110,000, the polylactic acid is selected from NatureWorks PLA4032D of the United States, the plasticizer is tributyl citrate, the antioxidant is bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, the substitution degree of carboxymethyl chitosan is 85%, the reinforcing filler is a composite of nano-silica and jute fiber, the mass ratio of nano-silica to jute fiber is 1:1, and the particle size of nano-silica is 50 nm - 80 nm.

[0026] The preparation method of the degradable medical packaging box material comprises the following specific steps: Mix poly(ethylene carbonate), polylactic acid, plasticizer, antioxidant and reinforcing filler evenly, heat and melt them at 160 °C, and extrude to obtain the degradable medical packaging box material.

[0027] Example 2 The difference between Example 2 and Example 1 is that in the raw materials of the degradable medical packaging box material, the usage amount of poly(ethylene carbonate) is 20 kg, the usage amount of polylactic acid is 40 kg, the usage amount of plasticizer is 3 kg, the usage amount of antioxidant is 1 kg, the usage amount of reinforcing filler is 8 kg, and the usage amount of carboxymethyl chitosan is 10 kg.

[0028] Example 3 The difference between Example 3 and Example 1 is that in the raw materials of the degradable medical packaging box material, the usage amount of poly(ethylene carbonate) is 30 kg, the usage amount of polylactic acid is 30 kg, the usage amount of plasticizer is 5 kg, the usage amount of antioxidant is 3 kg, the usage amount of reinforcing filler is 5 kg, and the usage amount of carboxymethyl chitosan is 5 kg.

[0029] Example 4 The difference between Example 4 and Example 1 is that in the reinforcing filler, nano-silica and jute fiber are pre-grafted to form a nano-silica-jute fiber grafted composite. The nano-silica-jute fiber grafted composite comprises the following raw materials in parts by weight: 10 kg of nano-silica, 13 kg of jute fiber, 0.8 kg of catalyst, 50 kg of solvent, and 10 kg of grafting assistant. Among them, the grafting assistant is toluene diisocyanate, the catalyst is dibutyltin dilaurate, and the solvent is toluene.

[0030] The preparation method of the degradable medical packaging box material comprises the following specific steps: S1: Immerse jute fibers in an aqueous sodium hydroxide solution with a mass fraction of 6%, with a solid-liquid ratio of 1:20. After soaking at 10°C for 8 h, add acetic acid to adjust the pH of the jute fibers to neutral. Take out the jute fibers and wash them with distilled water. After drying, obtain alkali-treated jute fibers. Divide the solvent and catalyst into three equal parts on average. After drying the nano-silica, mix it evenly with the grafting assistant and one part of the solvent to form a nano-silica mixture. Then add one part of the solvent catalyst to the nano-silica mixture, heat to 95°C and react for 5 h, and perform centrifugal separation. After drying the nano-silica treated by grafting, mix it with the alkali-treated jute fibers to form a composite liquid. Add the remaining solvent and the remaining catalyst to the composite liquid, heat to 95°C for catalytic reaction for 2 h, perform centrifugal separation, and obtain nano-silica-jute fiber grafted composite after drying.

[0031] S2: Mix poly(ethylene carbonate), polylactic acid, plasticizer, antioxidant, and nano-silica-jute fiber grafted composite evenly, heat and melt at 160°C, and extrude to obtain a degradable medical packaging box material.

[0032] Example 5 The difference between Example 5 and Example 4 is that the nano-silica-jute fiber grafted composite includes the following raw materials in parts by weight: 8 kg of nano-silica, 15 kg of jute fibers, 0.5 kg of catalyst, 40 kg of solvent, and 5 kg of grafting assistant.

[0033] Example 6 The difference between Example 6 and Example 4 is that the nano-silica-jute fiber grafted composite includes the following raw materials in parts by weight: 13 kg of nano-silica, 10 kg of jute fibers, 1 kg of catalyst, 60 kg of solvent, and 15 kg of grafting assistant.

[0034] Example 7 The difference between Example 7 and Example 4 is that the grafting assistant of the nano-silica-jute fiber grafted composite is silane coupling agent KH560.

[0035] Example 8 The difference between Example 8 and Example 4 is that poly(ethylene carbonate) is pre-compounded with wood powder and coupling agent. The particle size of the wood powder is 20 mesh, and the coupling agent is silane coupling agent 570.

[0036] The preparation method of the degradable medical packaging box material includes the following specific steps: S1: Immerse jute fibers in an aqueous sodium hydroxide solution with a mass fraction of 6%, with a solid-liquid ratio of 1:20. After soaking at 10°C for 8 h, add acetic acid to adjust the pH of the jute fibers to neutral. Take out the jute fibers and wash them with distilled water. After drying, obtain alkali-treated jute fibers. Divide the solvent and catalyst into three equal parts on average. After drying the nano-silica, mix it evenly with the grafting assistant and one part of the solvent to form a nano-silica mixed solution. Then add one part of the solvent catalyst to the nano-silica mixed solution, heat to 95°C and react for 5 h, followed by centrifugal separation. After drying the nano-silica after grafting treatment, mix it with the alkali-treated jute fibers to form a composite solution. Add the remaining solvent and the remaining catalyst to the composite solution, heat to 95°C for catalytic reaction for 2 h, followed by centrifugal separation. After drying, obtain a nano-silica-jute fiber graft composite.

[0037] S2: Mix poly(ethylene carbonate) and wood powder at 115°C for 10 min, then add a coupling agent and mix for 5 min. The mass ratio of poly(ethylene carbonate), wood powder, and coupling agent is 1:0.3:0.3. After cooling, obtain a poly(ethylene carbonate)-wood powder composite.

[0038] S3: Mix the poly(ethylene carbonate)-wood powder composite, polylactic acid, plasticizer, antioxidant, and nano-silica-jute fiber graft composite evenly, heat and melt at 160°C, and extrude to obtain a degradable medical packaging box material.

[0039] Example 9 The difference between Example 9 and Example 8 is that the mass ratio of poly(ethylene carbonate) to wood powder and coupling agent in the raw materials of the packaging box material is 1:0.2:0.4.

[0040] Example 10 The difference between Example 10 and Example 8 is that the mass ratio of poly(ethylene carbonate) to wood powder and coupling agent in the raw materials of the packaging box material is 1:0.4:0.2.

[0041] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the reinforcing filler in the raw materials of the medical packaging box material is nano-silica.

[0042] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that poly(ethylene carbonate) is not used in the raw materials of the medical packaging box material.

[0043] Performance Detection Test Perform the following performance detections on the degradable medical packaging box materials provided in Examples 1-10 and Comparative Examples 1-2 of the present application. The specific detection results are shown in Table 1.

[0044] Detection Method I. Tensile Strength and Bending Strength Referring to the standard of GB / T1040.2 - 2018 "Determination of Tensile Properties of Plastics", the tensile strength and fracture strain rate of the medical packaging box material prepared in this application are detected. Referring to the standard of GB / T9341 - 2008 "Determination of Flexural Properties of Plastics", the bending strength of the medical packaging box material prepared in this application is detected.

[0045] II. Heat Distortion The heat distortion temperature of the medical packaging box material prepared in this application is detected by a heat distortion temperature Vicat tester HDT / V3116.

[0046] Table 1. Data Sheet of Performance Detection Results It can be seen from the performance detection results that the packaging box material prepared in this application has good tensile strength, bending strength and thermal stability, reduces the phenomenon of deformation of the packaging box material during hot processing, and enhances the elongation at break and toughness of the packaging box material under the synergistic effect of each component. By comparing Comparative Example 1 - 2 with Example 1, it can be seen that not using jute fiber in Comparative Example 1 and not using poly (ethylene carbonate) in Comparative Example 2 will both reduce the strength, toughness and thermal stability of the packaging box material.

[0047] It can be seen from Examples 4 - 7 that by grafting nano - silica with jute fiber in advance to form a nano - silica - jute fiber grafted composite, the compatibility of silica, jute fiber and polymer matrix is enhanced, and the overall tensile strength and toughness of the packaging film material are improved. Among them, the grafting assistant used in Example 4 has a better effect, which may be because toluene diisocyanate has better activity and can better carry out grafting reactions with jute fiber and nano - silica simultaneously.

[0048] It can be seen from Examples 8 - 10 that poly (ethylene carbonate) is pre - mixed with wood powder and coupling agent. It can be seen from the performance detection results that the thermal stability and strength of the packaging material are significantly improved.

[0049] This specific embodiment is only an explanation of this application, and it is not a limitation of this application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of this application, it is protected by the patent law.

Claims

1. A degradable medical packaging material, characterized in that: The invention comprises the following raw materials in parts by weight: 20-30 parts of polymethylethylene carbonate, 30-40 parts of polylactic acid, 3-5 parts of plasticizer, 1-3 parts of antioxidant, 5-8 parts of reinforcing filler and 5-10 parts of carboxymethyl chitosan; the reinforcing filler is a composite of nano silicon dioxide and jute fiber.

2. The degradable medical packaging material according to claim 1, characterized in that: The nano silicon dioxide is grafted onto the jute fiber in advance.

3. The degradable medical packaging material according to claim 2, characterized in that: The grafting method comprises the following specific steps: pre-treating jute fiber with alkali, drying nano silicon dioxide and evenly mixing it with a grafting auxiliary agent and a solvent to form a nano silicon dioxide mixed liquid, then adding a catalyst to the nano silicon dioxide mixed liquid, heating for reaction, centrifugal separation, drying the grafted nano silicon dioxide and mixing it with the jute fiber treated with alkali to form a composite liquid, adding a solvent and a catalyst to the composite liquid, heating for catalytic reaction, centrifugal separation, and drying to obtain a nano silicon dioxide-jute fiber grafted composite.

4. The degradable medical packaging material according to claim 3, characterized in that: The heating reaction temperature is 90-100°C, and the heating catalytic reaction temperature is 90-100°C.

5. The degradable medical packaging material according to claim 3, characterized in that: The nano-silicon dioxide-jute fiber grafted composite comprises the following raw materials in parts by weight: 8-13 parts of nano-silicon dioxide, 10-15 parts of jute fiber, 0.5-1 part of catalyst, 40-60 parts of solvent and 5-15 parts of grafting auxiliary agent.

6. The degradable medical packaging material according to claim 5, characterized in that: The grafting auxiliary agent is toluene diisocyanate.

7. The degradable medical packaging material according to claim 1, characterized in that: The poly(methyl ethylene carbonate) is pre-compounded with wood powder and a coupling agent, and the mass ratio of the poly(methyl ethylene carbonate) to the wood powder and the coupling agent is 1:(0.2-0.4):(0.2-0.4).

8. A method for preparing the degradable medical packaging material according to any one of claims 1 to 7, characterized in that: The specific steps include: Polymethylethylene carbonate, polylactic acid, a plasticizer, an antioxidant and a reinforcing filler are uniformly mixed, heated and melted, and extruded to obtain a degradable medical packaging box material.

9. The method for preparing the degradable medical packaging box material according to claim 8, characterized in that: The specific steps include: The poly(methyl ethylene carbonate) and wood powder are uniformly mixed at 110-120° C., a coupling agent is added and mixed, and the mixture is cooled to obtain a poly(methyl ethylene carbonate)-wood powder composite; The poly(methyl ethylene carbonate)-wood powder composite, polylactic acid, a plasticizer, an antioxidant and a reinforcing filler are uniformly mixed, heated and melted, and extruded to obtain a degradable medical packaging box material.

10. The method for preparing the degradable medical packaging box material according to claim 9, characterized in that: The heating melting temperature is 150-170°C.

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