Native biomass fiber-pollen blended bioplastic as well as preparation method and application thereof

Abstract

The invention discloses a native biomass fiber-pollen blended bioplastic as well as a preparation method and application thereof, and relates to the technical field of bioplastics. The preparation method of the bioplastic comprises the following steps: taking natural fibers, crushing, adding water, and stirring to prepare a fiber suspension; the preparation method comprises the following steps: cleaning natural pollen to remove impurities and lipid on the surface, stirring by using alkali liquor, washing a mixed system to be neutral, and filtering to remove excessive moisture to obtain pollen microgel; uniformly mixing the fiber suspension and the pollen microgel to obtain mixed slurry; and blade-coating the mixed slurry on a mold, drying and stripping to obtain the native biomass fiber-pollen blended bioplastic. The native biomass fiber-pollen blended bioplastic provided by the invention has high mechanical strength, can easily realize water shaping and water splicing, and has good cyclic utilization and biodegradability; the preparation method utilizes a large amount of waste or low-added-value biomass resources, and is simple in process, low in production cost and less in environmental pollution.

Description

Technical Field

[0001] The invention relates to the technical field of bioplastics, in particular to primary biomass fiber-pollen blended bioplastics. Background Art

[0002] As the world pays more attention to environmental protection, the environmental pollution caused by traditional petroleum-based plastics has become increasingly prominent. For example, plastics face challenges such as high energy consumption and difficulty in recycling during processing; plastics are difficult to degrade naturally, causing serious harm to soil, water bodies and ecosystems; dispersed microplastics can enter organisms through the food chain, causing biological health problems. In order to meet these challenges, it is urgent to develop more environmentally friendly, efficient and sustainable plastic processing raw materials and technologies to reduce the impact on the ecological environment and human health and promote the green transformation of the plastics industry.

[0003] In recent years, bioplastics have attracted widespread attention as an environmentally friendly alternative material due to their advantages such as wide sources of natural biomass resources, renewability, and biodegradability. However, existing bioplastics still have many shortcomings in terms of processing methods, practical performance, and cost-effectiveness, which limits their large-scale application. For example, the preparation of some bioplastics relies on high temperature and high pressure conditions, which not only consumes a lot of energy, but may also destroy the natural structure of biomaterials and weaken their mechanical properties; others have strict requirements on the purity of raw materials, significantly increasing production costs and process complexity, and it is difficult to meet the market demand for green materials. Traditional bioplastics often have limitations such as insufficient mechanical strength, poor water resistance, and harsh degradation conditions. The degradation of many bioplastics requires specific environmental conditions (such as industrial composting facilities), and it is difficult to achieve rapid degradation in the natural environment, which may still have potential impacts on the environment.

[0004] Therefore, utilizing the advantages of natural biomass resources such as wide sources, renewability, and degradability to develop a bioplastic that is simple to process, has excellent performance, is easy to promote, and has excellent mechanical properties and processability has become an important research direction in the current bioplastics field. Summary of the invention

[0005] In view of the deficiencies of the above prior art, the present invention provides a native biomass fiber-pollen blended bioplastic and its preparation method and application. The present invention prepares natural fiber and pollen into corresponding fiber suspension and pollen microgel respectively, mixes the two evenly, and then scrapes and smears them on a mold and dries them to obtain a finished plastic product. This preparation method is simple in process, and the finished plastic product has excellent mechanical properties and recyclable characteristics, can easily achieve water shaping and water splicing, and also has good recyclability and biodegradability. It is specifically achieved through the following technologies.

[0006] A method for preparing a primary biomass fiber-pollen blended bioplastic comprises the following steps:

[0007] Take natural fiber, remove impurities, crush, add water and stir to prepare fiber suspension with a mass fraction of 0.1-2%; take natural pollen, add washing solvent to wash and remove surface impurities and lipids; then add alkali solution and stir, wash the mixed system until it is neutral, filter and remove excess water, and obtain pollen microgel with a solid content of 0.5-3%;

[0008] The fiber suspension and the pollen microgel are mixed evenly to obtain a mixed slurry;

[0009] The mixed slurry is scraped onto a template, and peeled off after drying to obtain a native biomass fiber-pollen blended bioplastic.

[0010] Furthermore, the natural pollen is added to a washing solvent for washing at a mass volume ratio of (0.1-10) g / mL, and the washing solvent is water, and one or more of ethanol, acetone, and ether.

[0011] Furthermore, the natural pollen is added to a washing solvent for washing at a mass volume ratio of 0.5 g / mL.

[0012] Furthermore, the alkali solution is a NaOH solution and / or a KOH solution with a mass concentration of 2-20%, and the mass volume ratio of the natural pollen to the alkali solution is (0.1-1) g / mL.

[0013] Furthermore, the alkali solution is a NaOH solution and / or a KOH solution with a mass fraction of 10%, and the mass volume ratio of the natural pollen to the alkali solution is 0.5 g / mL.

[0014] Furthermore, the mass ratio of the fiber suspension to the pollen microgel is 1:(1-9).

[0015] Furthermore, the mass ratio of the fiber suspension to the pollen microgel is 3:10.

[0016] Furthermore, the thickness of the mixed slurry scraped onto the template is 1-10 mm.

[0017] Furthermore, the drying conditions after the mixed slurry is applied on the template are: drying at 25-60° C., or natural drying.

[0018] Furthermore, the natural fiber is a fiber of plant origin.

[0019] Furthermore, the plant source includes but is not limited to any one or more of cotton, bamboo, straw, and wood (the wood may be derived from any tree, such as coniferous trees or broad-leaved trees).

[0020] The pollen used in the present invention is natural pollen of any flowering plant, including but not limited to one or more of sunflower, rose, lotus, rape, corn, camellia, motherwort, pine pollen and the like.

[0021] The present invention also provides a native biomass fiber-pollen blended bioplastic prepared by any one of the above preparation methods.

[0022] The native biomass fiber-pollen blended bioplastic prepared by the present invention generally has a thickness of 50-200 μm; after testing, its tensile strength reaches 20-60 MPa, and its elongation at break reaches 1-10%; it also has excellent recyclability and degradability.

[0023] The present invention also provides the application of the above-mentioned primary biomass fiber-pollen blended bioplastic, which is used to prepare packaging materials (such as food packaging, express packaging, take-out packaging and plastic bags, etc.), paper products (such as disposable tableware, straws, etc.), film materials (such as agricultural films, etc.), coating materials, daily necessities and textiles after being plasticized and spliced ​​by water. This bioplastic can effectively replace traditional plastics, has significant environmental friendliness and practical value, and meets the needs of sustainable development.

[0024] Compared with the prior art, the present invention is beneficial in that:

[0025] 1. The native biomass fiber-pollen blended bioplastic provided by the present invention makes maximum use of waste or low-value-added biomass resources, which not only avoids the environmental burden brought by plastics, effectively reduces energy consumption and environmental pollution, improves the utilization value of biomass resources, but also effectively reduces production costs and improves the market competitiveness of products.

[0026] 2. The bioplastic prepared by the present invention has high mechanical strength. The mechanical strength (tensile strength) of the native biomass fiber-pollen blended bioplastic with a thickness of 100 μm and a fiber content of 30% can reach 52 MPa. It can be easily water-shaped and water-spliced, and has good recyclability and biodegradability.

[0027] 3. The method for preparing the primary biomass fiber-pollen blended bioplastic provided by the present invention has a simple process, convenient operation, and is easy to promote and apply on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the preparation process of native biomass fiber-pollen blended bioplastics.

[0029] Figure 2Schematic diagram of the actual preparation process of raw biomass fiber-pollen blended bioplastics. A: Preparation of fiber suspension; B: Preparation of pollen microgel; C: Preparation of fiber-pollen blended bioplastics after fiber-pollen slurry coating and drying.

[0030] Figure 3 A diagram of the folding and curling of the blended bioplastic prepared in Example 1.

[0031] Figure 4 These are SEM images of the surface and cross-section of the blended bioplastic prepared in Example 1.

[0032] Figure 5 The mechanical properties of the blended bioplastics with different fiber contents prepared in Examples 1 to 5. A: stress-strain curve; B: bar graph of tensile strength and Young's modulus.

[0033] Figure 6 The stress-strain curves of the blended bioplastics prepared in Examples 6-9.

[0034] Figure 7 The water processability of the blended bioplastic prepared in Example 1. Wherein, A: water shaping ability; B: water shaping ability of Examples 2-9; C: water welding ability.

[0035] Figure 8 The recyclability of the blended bioplastic prepared in Example 1.

[0036] Fig. 9 The degradability of the blended bioplastic prepared in Example 1 and common plastics in the natural soil environment. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be 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.

[0038] In some embodiments of the present invention, a method for preparing a primary biomass fiber-pollen blended bioplastic is provided, such as Figure 1 and 2 The specific steps are as follows: take natural fiber, remove impurities and rhizomes, crush, add water and stir to make a fiber suspension with a mass fraction of 0.1-2%; take natural pollen, use a washing solvent to wash to remove surface impurities and lipids, then add alkali solution and stir, wash the mixed system to neutrality, filter to remove excess water, and obtain pollen microgel with a solid content of 0.5-3%;

[0039] The fiber suspension and the pollen microgel are mixed evenly to obtain a mixed slurry;

[0040] The mixed slurry is scraped onto a template (such as a plastic plate, etc.), and peeled off after drying to obtain a native biomass fiber-pollen blended bioplastic.

[0041] Optionally, in the above preparation method, the washing solvent is water, one or more of ethanol, acetone, and ether, and the mass volume ratio of natural pollen to the washing solvent is (0.1-10) g / mL. The purpose of repeatedly washing natural pollen with the washing solvent is to remove surface impurities and lipids.

[0042] Optionally, the alkali solution can be selected from NaOH solution and / or KOH solution, and the specific concentration can be adjusted according to actual conditions. Generally, an alkali solution with a mass fraction of 2-20% can be selected. The purpose of using the alkali solution for soaking treatment is to soften the shell of natural pollen and remove the cytoplasm in natural pollen cells. Further optionally, the alkali solution can be selected from NaOH solution and / or KOH solution.

[0043] Optionally, the mass volume ratio of natural pollen to the alkali solution is (0.1-1) g / mL.

[0044] Optionally, the mass ratio of the fiber suspension to the pollen microgel is 1:(1-9).

[0045] Optionally, the thickness of the mixed slurry scraped onto the template is 1-10 mm.

[0046] Optionally, the mixed slurry after scraping can be dried at 25-60°C or naturally dried at room temperature. The drying time can be freely determined, subject to the mixed slurry being able to be completely peeled off the template.

[0047] In the raw materials of the native biomass fiber-pollen blended bioplastic provided by the present invention, the natural fiber is a fiber of plant origin. Optionally, the plant fiber includes but is not limited to any one of cotton, bamboo, straw, and wood (the wood can be derived from any tree, such as coniferous trees or broad-leaved trees).

[0048] In the raw materials of the primary biomass fiber-pollen blended bioplastic provided by the present invention, the natural pollen is pollen of any common flowering plant species. The plant sources of the natural pollen include, but are not limited to, one or more of sunflower, rose, lotus, rape, corn, camellia, motherwort, and pine pollen.

[0049] Example 1

[0050] The method for preparing the primary biomass fiber-pollen blended bioplastic provided in this embodiment comprises the following steps:

[0051] (1) Take 3 g of natural plant fiber, select and remove root and stem impurities, add 300 mL of water, and use a homogenizer to crush it to prepare a fiber suspension with a mass fraction of 1%.

[0052] 200 g of natural pollen was repeatedly stirred by adding 200 mL of water and 400 mL of ethanol to remove impurities and lipids on the surface of the natural pollen; then it was immersed in a KOH solution with a mass concentration of 10% to remove the cytoplasm and soften the outer shell of the natural pollen particles, and the solid-liquid ratio of natural pollen to NaOH solution was 0.5 g / mL; then the natural pollen was rinsed with water until neutral, and the excess water was filtered to complete the concentration, thereby obtaining a high-viscosity pollen microgel with a solid content of 0.5-3%.

[0053] (2) The fiber suspension and the pollen microgel are mixed evenly in a mass ratio of 3:10, and the excess water is removed by filtration to complete concentration, thereby forming a mixed slurry containing fiber and natural pollen;

[0054] (3) The mixed slurry containing fibers and natural pollen is scraped onto a plastic plate with a thickness of 5 mm and allowed to dry naturally until it can be directly peeled off to obtain a fiber-pollen blended bioplastic.

[0055] The fiber-pollen blended bioplastic prepared in this example is as follows Figure 3 The SEM images of the surface and cross section of the blended bioplastics are shown in Figure 4 shown.

[0056] Embodiment 2-5

[0057] The preparation method of the native biomass fiber-pollen blended bioplastic provided in Examples 2-5 is basically the same as that in Example 1, except for the mass ratio of the fiber suspension and the pollen microgel, as shown in Table 1 below.

[0058] Table 1

[0059]

[0060] Embodiment 6-9

[0061] The preparation methods of the native biomass fiber-pollen blended bioplastics provided in Examples 6-9 are basically the same as those in Example 1, except for the type of washing solvent used, and the type, mass concentration and amount of alkali solution, as shown in Table 2 below.

[0062] Table 2

[0063]

[0064] Test Example: Performance test of the original biomass fiber-pollen blended bioplastics prepared in Examples 1-9

[0065] 1. Mechanical properties test

[0066] Mechanical properties are key indicators for measuring material strength, toughness, durability and reliability, and directly affect the applicability and service life of materials in the fields of industry, construction, packaging, and medical treatment. By deeply studying the mechanical properties of materials, we can optimize their structural design and improve their key properties such as tensile strength, impact resistance, and wear resistance. In addition, the improvement of mechanical properties helps to extend the service life of materials and reduce resource waste and economic losses caused by material failure.

[0067] In order to explore the strength, toughness and durability of the fiber-pollen blended bioplastic, the blended bioplastics prepared in Examples 1-9 were subjected to a tensile strength test according to GB / T 1040-2006. At the same time, a control group was set up, specifically, the pollen microgel obtained in step (1) of Example 1 was directly scraped onto a plastic plate, and then dried and peeled off in the same manner as in Example 1 to obtain a corresponding plastic sample. That is, no fiber was added to the plastic sample of the control group (addition amount 0).

[0068] The experimental results are as follows Figure 5 As shown in the figure, as the fiber content increases from 0 to 30%, the strength and modulus of the fiber-pollen blended bioplastics are significantly improved; when the fiber content further increases to 40% and 50%, its mechanical properties decrease. Among them, the sample with a fiber content of 30% exhibits the best mechanical properties, with a tensile strength of 52.22 MPa, a Young's modulus of 2.24 GPa, and a strain of 6.15%.

[0069] The experimental results are as follows Figure 6 As shown, by changing the type of washing solvent, type, mass concentration and amount of alkali solution used in the preparation of pollen microgels, the mechanical strength and modulus of the fiber-pollen blended bioplastics remain almost the same, with a mechanical strength of 50-55 MPa, a Young's modulus of 2.01-2.32 GPa, and a strain of 4.53-6.49%.

[0070] The results of mechanical property tests show that the mechanical properties of fiber-pollen blended bioplastics are mainly affected by the fiber content, while changes in the conditions of the pollen microgel preparation process have little effect on it. Specifically, when the content of natural fiber in the fiber-pollen blended bioplastic is 30%, the mechanical properties of the fiber-pollen blended bioplastic are comparable to those of the currently widely used thermoplastics and biodegradable plastics, and even show better characteristics in some performance indicators.

[0071] 2. Water shaping and water splicing performance

[0072] The processing of traditional plastics usually requires high temperature, high pressure or organic solvents, which not only consumes a lot of energy, but also may produce harmful chemicals and pollute the environment. Materials with water processing characteristics can be formed and processed under mild conditions using water as a medium, significantly reducing energy consumption and environmental pollution. The water processing process is simple and easy to operate, and can adapt to the preparation needs of various shapes and sizes, improving the application flexibility and production efficiency of the material.

[0073] In order to evaluate the water shaping and water splicing properties of the fiber-pollen blended bioplastics prepared in Examples 1-9, they were immersed in water and then observed for their shaping ability, splicing ability and structural stability.

[0074] The experimental results are as follows Figure 7 A-7C. Figure 7 A It can be seen that when the blended bioplastic prepared in Example 1 is soaked in water, after 5 minutes of soaking, the material fully absorbs water and is softened; it can then be placed in different molds for fixed molding according to needs, such as oval, circular, square and triangular shapes. This process only requires water soaking and natural drying to achieve the molding of the material. No complex equipment or high temperature and high pressure conditions are required, and the process is simple and easy. After natural drying, the material can maintain the shape given by the mold to form a stable three-dimensional structure. The material has the characteristic of repeatable shaping. By soaking in water again, it can be softened again and plasticity can be restored, thereby achieving multiple molding and repeated use. From Figure 7 B It can be seen that the blended bioplastics prepared in Examples 2-9 all have certain water shaping ability, but the difference in mechanical properties caused by different fiber contents leads to slight differences in water shaping ability. The above water shaping process does not involve energy consumption and harmful chemical emissions, which is in line with the concept of green environmental protection and sustainable development.

[0075] from Figure 7 C As can be seen, the present invention also provides a simple and efficient interface connection method: water is only needed to be used for treatment at the interface of two independent bioplastics, and water can soften the interface and allow the two to embed into each other. After natural drying, the two independent bioplastics can be firmly pasted together. This method does not require additional adhesives or complex processes, is easy to operate and environmentally friendly, significantly improves the ease of use and processability of the material, and further expands its potential in practical applications.

[0076] The above experimental results fully demonstrate that fiber-pollen blended bioplastics can be shaped and spliced ​​in a water environment, significantly reducing energy consumption and environmental pollution.

[0077] 3. Recyclability

[0078] Plastic recycling technologies mainly include physical recycling, chemical recycling and biological recycling. Among them, physical recycling is the most widely used technology at present. It uses mechanical methods to clean, crush, melt and reprocess waste plastics to make new plastic products. However, physical recycling is less effective for mixed plastics or contaminated plastics, and the performance of plastics may deteriorate after multiple recycling. The application of recycling technology is conducive to reducing resource consumption, reducing environmental pollution, saving energy, reducing costs, and promoting sustainable development.

[0079] In order to explore the recyclability of the fiber-pollen blended bioplastic, in this test example, the fiber-pollen blended bioplastic prepared in Example 1 was crushed and re-prepared to achieve its recycling.

[0080] The discarded fiber-pollen blended bioplastics can be cut into small pieces, soaked in water, crushed and pulverized, and redispersed to form a uniform fiber-pollen slurry (such as Figure 8 The slurry is then spread on a plastic plate and peeled off after drying to re-produce fiber-pollen bioplastic.

[0081] The above experimental results fully demonstrate that the entire recycling and remanufacturing process of fiber-pollen blended bioplastics only requires water and physical treatment, without complex equipment or chemical additives. The process is simple and environmentally friendly, and it reduces waste disposal costs and achieves efficient recycling of resources.

[0082] 4. Degradability

[0083] Traditional plastics are difficult to degrade in the natural environment, and long-term accumulation will lead to serious environmental pollution problems, such as soil degradation, water pollution, and the harm of microplastics to the ecosystem. Biodegradable materials can be decomposed by microorganisms under natural conditions and eventually converted into water, carbon dioxide and organic matter, thereby reducing the negative impact on the environment. The application of biodegradable materials not only helps alleviate the problem of plastic pollution, but also reduces dependence on non-renewable resources and promotes the recycling of resources.

[0084] In order to evaluate the degradation performance of fiber-pollen blended bioplastics, in this test example, polyethylene terephthalate (PET), polyvinyl chloride (PVC) and fiber-pollen blended bioplastic samples (BH) of the same size were buried in a natural soil environment at a depth of 10 cm, and their degradation was observed regularly.

[0085] The experimental results are as follows Fig. 9 As shown in the figure, two months after the fiber-pollen blended bioplastic was buried in the soil, holes began to appear on the surface of the material, and the degree of cracking gradually increased over time; after six months, the material was completely degraded, and no visible fragments remained.

[0086] Under the same experimental conditions, after 6 months of observation, the PET and PVC samples did not show any obvious signs of degradation and remained intact.

[0087] The above experimental results fully demonstrate that the fiber-pollen blended bioplastic has excellent degradation performance in the natural soil environment and can be completely degraded in a relatively short time, while traditional plastics (such as PET and PVC) are difficult to degrade under the same conditions.

[0088] In summary, the present invention provides a primary biomass fiber-pollen blended bioplastic, which uses natural fiber and natural pollen as raw materials, and through a simple pretreatment and mixing process, the two components are interwoven to form a dense structure with fiber as a grid and natural pollen as a matrix filling. The blended bioplastic provided by the present invention has excellent mechanical strength, water shaping and water splicing properties, recyclability and degradability, and can meet the needs of various application scenarios. This blended bioplastic not only promotes the widespread application of biomass materials in the fields of industry, packaging, and medical treatment, but also has significant practical value and promotion potential. At the same time, its environmentally friendly characteristics help promote sustainable development, reduce economic costs and meet market demand, and provide an effective solution to the problem of plastic pollution. The present invention has important scientific significance and application prospects in the fields of materials science and environmental protection.

[0089] The above specific embodiments describe the implementation of the present invention in detail, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, the technical solution of the present invention can be modified and changed in many simple ways, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A method for preparing a primary biomass fiber-pollen blended bioplastic, characterized in that: The following steps are involved: Take natural fiber, remove impurities, crush, add water and stir to prepare fiber suspension with a mass fraction of 0.1-2%; take natural pollen and use washing solvent to wash to remove impurities and lipids on the surface; then add alkali solution and stir, wash the mixed system until it is neutral, filter and remove excess water, and obtain pollen microgel with a solid content of 0.5-3%; The fiber suspension and the pollen microgel are mixed evenly to obtain a mixed slurry; The mixed slurry is scraped onto a mold, and peeled off after drying to obtain a native biomass fiber-pollen blended bioplastic.

2. The method for preparing the primary biomass fiber-pollen blended bioplastic according to claim 1, characterized in that: The natural pollen is added to a washing solvent for washing at a mass volume ratio of (0.1-10) g / mL, wherein the washing solvent is water, and one or more of ethanol, acetone, and ether.

3. The method for preparing the primary biomass fiber-pollen blended bioplastic according to claim 1, characterized in that: The alkali solution is a NaOH solution and / or a KOH solution with a mass concentration of 2-20%, and the mass volume ratio of the natural pollen to the alkali solution is (0.1-1) g / mL.

4. The method for preparing the primary biomass fiber-pollen blended bioplastic according to claim 1, characterized in that: The mass ratio of the fiber suspension to the pollen microgel is 1:(1-9).

5. The method for preparing the primary biomass fiber-pollen blended bioplastic according to claim 1, characterized in that: The thickness of the mixed slurry applied on the template is 1-10 mm.

6. The method for preparing the primary biomass fiber-pollen blended bioplastic according to claim 1, characterized in that: The drying conditions after the mixed slurry is scraped onto the template are: drying at 25-60° C., or natural drying.

7. The method for preparing the primary biomass fiber-pollen blended bioplastic according to claim 1, characterized in that: The natural fibers are fibers of plant origin.

8. The method for preparing the primary biomass fiber-pollen blended bioplastic according to claim 7, characterized in that: The plant source includes but is not limited to any one or more of cotton, bamboo, straw, and wood.

9. A native biomass fiber-pollen blended bioplastic prepared by the preparation method according to any one of claims 1 to 8.

10. An application of the primary biomass fiber-pollen blended bioplastic according to claim 9, characterized in that: The native biomass fiber-pollen blended bioplastic is used to prepare packaging materials, paper products, film materials, coating materials, daily necessities and textiles after being plasticized and spliced ​​by water.

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