A bioplastic-reinforced polyurethane foam and its preparation method

Abstract

This application discloses bioplastic-reinforced polyurethane foam and its preparation method, relating to the field of bioplastics technology, and aims to solve the technical problem that the performance of bio-based plastics prepared by existing technologies is difficult to meet application requirements. The preparation method includes: dispersing microalgae powder in deionized water to obtain a microalgae powder dispersion; adding a polyol to the microalgae powder dispersion to obtain a polyol-modified microalgae powder dispersion; drying the polyol-modified microalgae powder dispersion in an oven, collecting the solid product, and grinding it into powder using a pulverizer to obtain polyol-modified microalgae powder; adding the polyol-modified microalgae powder, catalyst, foaming agent, and stabilizer to a polyether polyol, and continuously stirring to obtain a polyol mixture; thoroughly mixing the polyol mixture with a polyisocyanate under mechanical stirring, and casting the mixture into a mold for foaming to obtain a bioplastic-reinforced polyurethane foam material.

Description

Technical Field

[0001] This application relates to the field of bioplastics technology, specifically to a bioplastic-reinforced polyurethane foam and its preparation method. Background Technology

[0002] The preparation process of bio-based plastics faces multiple challenges in the current technological field. Specifically, the raw materials for bio-based plastics must undergo a series of complex chemical and physical processing steps, including dissolution, regeneration, cross-linking, centrifugation, washing, high-temperature drying, and hot pressing, before they can be transformed into the final product. This process inevitably consumes large amounts of electricity, water, materials, and human resources. Furthermore, the use of toxic and hazardous chemicals such as organic solvents, acids, alkalis, and salts is difficult to avoid. This not only fails to effectively reduce the carbon emissions of bio-based plastics throughout their life cycle but also imposes a significant burden on the environment.

[0003] The core objective of existing technologies is to transform bio-based raw materials into processable forms such as solutions, powders, and films through physical and chemical means. However, this transformation process often involves the destruction of the original material structure, and there is a lack of effective technologies for precise control of the material's microstructure, making it difficult to prepare materials with optimal mechanical properties. Furthermore, the surface functional group control technology for bioplastics and their intermediates also has significant shortcomings, directly reducing their processing performance. For example, when used as a reinforcing material, the lack of surface functional groups such as free hydroxyl groups makes it difficult for bioplastics to form a strong bond with matrix materials such as polyurethane. Simultaneously, the insufficient surface hydroxyl groups also reduce the dispersibility of bioplastics in water, further weakening their processing performance.

[0004] In terms of reinforcing and toughening polyurethane, existing technologies mainly achieve this by introducing rigid, flexible, and multiple hydrogen-bonded groups into the polymer structure. Specific processes involve adding modifiers, crosslinkers, and chain extenders during polyurethane polymerization. However, the preparation of modifiers and chain extenders is complex, involving multiple chemical reactions, which further increases the complexity of the polyurethane process and its environmental costs. Furthermore, when using carbon fibers or glass fibers as reinforcing materials, although surface-active groups such as hydroxyl groups can be introduced through surface modification, this process requires harsh reaction conditions, and the reinforcing materials such as fibers have limited impact on the shear properties of polyurethane, thus making it difficult to significantly improve the impact resistance of the composite material.

[0005] In conclusion, the preparation of bio-based plastics and their application in polyurethane composites still face many challenges and require further technological innovation and optimization. Summary of the Invention

[0006] The main objective of this application is to provide a bioplastic-reinforced polyurethane foam and its preparation method, aiming to solve the technical problem that the performance of bio-based plastics prepared by existing technologies is difficult to meet application requirements.

[0007] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0008] In a first aspect, embodiments of this application provide a method for preparing bioplastic-reinforced polyurethane foam, comprising the following steps:

[0009] Microalgae powder was dispersed in deionized water under mechanical stirring to obtain a microalgae powder dispersion.

[0010] Under mechanical stirring, polyols are added to the microalgae powder dispersion. After stirring for 10-15 minutes, the mixture is heated to 50℃-80℃ and reacted at this temperature for 2-6 hours to obtain a polyol-modified microalgae powder dispersion.

[0011] The polyol-modified microalgae powder dispersion was dried in an oven at 60℃-100℃ for 48-120 hours. The solid product was collected and ground into powder using a pulverizer to obtain polyol-modified microalgae powder.

[0012] Under mechanical stirring, the polyol-modified microalgae powder, catalyst, foaming agent, and stabilizer are added to the polyether polyol, and the mixture is stirred continuously for 0.5-1 hour to obtain a polyol mixture.

[0013] Under mechanical stirring, the polyol mixture and polyisocyanate are thoroughly mixed in a ratio of 1:1 to 4:1, and the mixture is poured into a mold and foamed at 60℃-100℃ to obtain a bioplastic-reinforced polyurethane foam material.

[0014] As some optional embodiments of this application, the microalgae powder includes one or more of Chlorella powder, Microcystis powder, Giant kelp powder, Spirulina powder and seaweed powder, and the particle size of the microalgae powder is 40 mesh-160 mesh.

[0015] As some optional embodiments of this application, the polyol includes one or more of epoxy resin, polyethylene glycol, and castor oil, wherein the molecular weight of the polyol is 800-2000, and the concentration added is 2 mg / mL. -1 -20mg mL -1 .

[0016] As some alternative embodiments of this application, the catalyst includes one or more of ethylenediamine, N,N-dimethylhexadecanamine, trimethylenediamine, bismuth isooctanoate, bismuth neodecanoate, stannous octoate, and dibutyltin dilaurate.

[0017] As some alternative embodiments of this application, the foaming agent includes one or more of water, cyclopentane, n-pentane, isopentane, pentafluoropropane, and pentafluorobutane.

[0018] As some optional embodiments of this application, the stabilizer includes one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, polycarbodiimide, and monocarbodiimide.

[0019] As some optional embodiments of this application, the volume fraction of the modified microalgae powder is 0.2%-6.4%.

[0020] As some optional embodiments of this application, the polyisocyanate includes one or more of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and naphthalene-1,5-diisocyanate (NDI).

[0021] Secondly, embodiments of this application also provide a bioplastic-reinforced polyurethane foam, which is prepared by the bioplastic-reinforced polyurethane foam preparation method described above.

[0022] As some optional embodiments of this application, the bioplastic-reinforced polyurethane foam has a Young's modulus of 0.2 MPa-0.3 MPa, a compressive resilience stress of 70 kPa-180 kPa at 25% compression ratio, and an energy absorption capacity of 10.8 x 10⁻⁶ kPa. 4 J m -3 .

[0023] Compared to existing technologies, the technical solution of this application reinforces polyurethane foam materials using bioplastics with optimized micro / nanostructures, surface activity, and shear properties. The optimized micro / nanostructure of this bioplastic endows it with high strength properties, and its abundant surface free hydroxyl groups enable it to form dynamic and reversible hydrogen bonds with the polyurethane polymer network. Its superior shear properties effectively enhance the strength of the polyurethane matrix under shear stresses such as impact. Compared to polyurethane foam materials without bioplastic reinforcement, the bioplastic-reinforced polyurethane foam material of this application exhibits a 30% increase in Young's modulus, a 13% increase in compressive resilience stress, and an 11% improvement in energy absorption capacity. In other words, this application proposes a simple and environmentally friendly method to achieve the preparation of bioplastics, optimization of micro / nanostructures, and enhancement of surface activity. The prepared bioplastics exhibit excellent shear response properties, significantly enhancing the impact resistance of polyurethane foam materials, and have broad application prospects in multiple fields such as sports protection, equipment protection, and battery protection. Attached Figure Description

[0024] Figure 1 This is an X-ray diffraction pattern of the bioplastic and microalgae powder raw materials prepared in the embodiments of the present invention.

[0025] Figure 2 This is the Fourier transform infrared spectrum of the bioplastic and microalgae powder raw materials prepared in the embodiments of the present invention.

[0026] Figure 3 The stress-strain curves of the bioplastic-reinforced polyurethane foam prepared in the embodiments of the present invention are shown; polyurethane foam with added microalgae powder and polyurethane foam without added microalgae powder under the same process conditions are used as experimental controls.

[0027] Figure 4 These are the compression rebound stress-strain curves and energy absorption bar graphs of the bioplastic-reinforced polyurethane foam prepared in the embodiments of the present invention; polyurethane foam with added microalgae powder and polyurethane foam without added microalgae powder under the same process conditions are used as experimental controls.

[0028] Figure 5 These are scanning electron microscope images of the bioplastics and microalgae powder raw materials prepared in the embodiments of the present invention.

[0029] Figure 6 This is a dynamic light scattering particle size distribution diagram of the bioplastic and microalgae powder raw materials prepared in the embodiments of the present invention.

[0030] Figure 7 The images shown are scanning electron microscope (SEM) images of the surface of the bioplastic-reinforced polyurethane foam prepared according to embodiments of the present invention; SEM images of the surface of polyurethane foam with added microalgae powder raw material under the same process conditions are used as experimental controls. Detailed Implementation

[0031] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0032] Micro / nanostructure engineering refers to the process of precisely controlling the micron- and nano-scale structures of materials using physical and chemical methods to achieve specific physical or chemical properties. Bioplastics are plastic products whose main components are bio-based materials, such as bio-based packaging materials, films, and sheets, typically obtained by processing bio-based materials such as lignin, proteins, and cellulose. Polyurethane is a polymer material formed by the polymerization reaction of polyisocyanates and polyols, linked by urethane bonds. Impact-resistant foam refers to foamed polymer materials that absorb impact energy and reduce impact transmission force.

[0033] Traditional plastic materials, such as polyethylene, polypropylene, and polyester, are difficult to recycle and degrade naturally, and their overuse places a significant burden on the Earth's environment. Utilizing bio-based materials as raw materials and processing them to produce biorecyclable and biodegradable bioplastics is an effective way to solve the environmental pollution caused by traditional plastics. For example, prior art 1 uses lignin and cellulose as raw materials to prepare lignin / cellulose bioplastics through processes such as alkaline dissolution, acid regeneration, chemical cross-linking, water washing, high-temperature drying, and hot pressing; prior art 2 uses cellulose, protein, lignin, tannic acid, tea polyphenols, and other raw materials to prepare biodegradable bio-based plastics through processes such as solvent dissolution, mixing, centrifugation, drying, and hot pressing; prior art 3 uses egg white liquid as raw material to prepare soft and water-insoluble egg white bioplastics through processes such as high-speed centrifugation purification, cooking, drying, and heat treatment; prior art 4 uses waste feathers as raw material to prepare high-toughness and high-wet-strength keratin bioplastics through processes such as dissolution, centrifugation, salting out, freeze drying, grinding, dispersion, casting, denaturation, and drying; and prior art 5 uses fungal mycelial fiber membranes as raw material to prepare mycelial bioplastic films through processes such as mycelial culture, glycerol soaking, washing, drying, and hot pressing.

[0034] Polyurethane foam has a wide range of applications in human and object protection, construction, footwear, and artificial leather. By enhancing the mechanical strength and toughness of polyurethane, its protective, supportive, energy-absorbing, and abrasion-resistant properties can be significantly improved, as well as its molding and die-cutting processing properties. Currently, the main methods for enhancing the mechanical properties and toughness of polyurethane include: (1) designing the polymer structure of polyurethane and introducing rigid, flexible groups and hydrogen bonds to enhance its mechanical strength and toughness; (2) using fiber materials as structural reinforcement units, dispersing and integrating them into the polyurethane polymer network to form composite materials with higher mechanical properties. For example, prior art 6 effectively improves the strength and toughness of polyurethane foam and reduces the shedding rate during die-cutting by introducing rigid polycarbonate, flexible polyoxytetramethylene glycol, and hyperbranched polyester structure into the polyurethane polymer structure; prior art 7 introduces the functional group 2-amino-5-(2-hydroxyethyl)-6-methyl-4[1H]-pyrimidinone into the polyurethane molecular structure through the chain extender 2,2-dimethylolpropionic acid, forming a reversible quadruple hydrogen bond structure, and improves the energy absorption performance and impact resistance of the material through the reversible dissociation of hydrogen bonds; prior art 8 prepares a modified crosslinking agent by condensing 4-(2-hydroxybutyl)phenylethylamine with 4-(2-hydroxybutyl)benzaldehyde, and reacts it with polyisocyanate to introduce a hydroxybenzocrown ether cyclic structure into the polyurethane polymer structure, thereby improving its mechanical strength; at the same time, carbon fiber, glass fiber and other materials are introduced during the molding process to further improve the mechanical strength of the matrix.

[0035] However, in the aforementioned existing technologies, the raw materials for bio-based plastics require complex chemical and physical treatments, such as dissolution, regeneration, cross-linking, centrifugation, washing, high-temperature drying, and hot pressing, before the final bio-based plastics can be obtained. The raw material processing consumes significant amounts of electricity, water, materials, and manpower, and uses toxic and harmful chemicals such as organic solvents, acids, alkalis, and salts. This not only fails to effectively reduce the carbon emissions of bio-based plastics throughout their life cycle but also places a significant burden on the environment. Furthermore, the main purpose of these technical solutions is to convert bio-based raw materials into processable solutions, powders, films, etc., through physical and chemical methods. In this process, the original structure of the material is damaged, and there is a lack of effective methods for precisely controlling the microstructure of the material, making it difficult to obtain materials with optimal mechanical properties.

[0036] It is evident that existing technologies lack technical solutions for regulating the surface functional groups of bioplastics and their intermediates, which significantly reduces their processing performance. When used as reinforcing materials, bioplastics lack free hydroxyl groups and other surface functional groups, making it difficult to form a strong bond with matrix materials such as polyurethane. The lack of surface hydroxyl groups also makes it difficult for bioplastics to disperse uniformly in water, thus reducing their processing performance. Current technologies primarily achieve reinforcement and toughening by introducing rigid, flexible, and multiple hydrogen-bonded groups into the polyurethane polymer structure. Specific processes include adding modifiers, crosslinkers, chain extenders, and other auxiliaries during polyurethane polymerization. The preparation of modifiers and chain extenders requires complex chemical processes, further increasing the processing and environmental costs of polyurethane. When using carbon fibers, glass fibers, etc., as reinforcing materials, surface modification is required under harsh reaction conditions to introduce surface-active groups such as hydroxyl groups. These reinforcing materials have little impact on the shear properties of polyurethane and cannot effectively improve the impact resistance of the composite material.

[0037] To address the shortcomings of the existing technology, this application provides a green preparation method for high-strength bioplastics with optimized micro / nano structure, surface activity, and shear properties, and its application in reinforcing polyurethane impact-resistant materials. The preparation method of the bioplastic-reinforced polyurethane foam includes the following steps:

[0038] Microalgae powder was dispersed in deionized water under mechanical stirring to obtain a microalgae powder dispersion.

[0039] Under mechanical stirring, polyols are added to the microalgae powder dispersion. After stirring for 10-15 minutes, the mixture is heated to 50℃-80℃ and reacted at this temperature for 2-6 hours to obtain a polyol-modified microalgae powder dispersion.

[0040] The polyol-modified microalgae powder dispersion was dried in an oven at 60℃-100℃ for 48-120 hours. The solid product was collected and ground into powder using a pulverizer to obtain polyol-modified microalgae powder.

[0041] Under mechanical stirring, the polyol-modified microalgae powder, catalyst, foaming agent, and stabilizer are added to the polyether polyol, and the mixture is stirred continuously for 0.5-1 hour to obtain a polyol mixture.

[0042] Under mechanical stirring, the polyol mixture and polyisocyanate are thoroughly mixed in a ratio of 1:1 to 4:1, and the mixture is poured into a mold and foamed at 60℃-100℃ to obtain a bioplastic-reinforced polyurethane foam material.

[0043] As some optional embodiments of this application, the microalgae powder includes one or more of Chlorella powder, Microcystis powder, Giant kelp powder, Spirulina powder and seaweed powder, and the particle size of the microalgae powder is 40 mesh-160 mesh.

[0044] Preferably, the polyol comprises one or more of epoxy resin, polyethylene glycol, and castor oil, wherein the molecular weight of the polyol is 800-2000, and the concentration added is 2 mg / mL. -1 -20mg mL -1 .

[0045] Preferably, the catalyst comprises one or more of ethylenediamine, N,N-dimethylhexadecanamine, trimethylenediamine, bismuth isooctanoate, bismuth neodecanoate, stannous octoate, and dibutyltin dilaurate.

[0046] Preferably, the foaming agent includes one or more of water, cyclopentane, n-pentane, isopentane, pentafluoropropane, and pentafluorobutane.

[0047] Preferably, the stabilizer comprises one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, polycarbodiimide, and monocarbodiimide.

[0048] Preferably, the volume fraction of the modified microalgae powder is 0.2%-6.4%.

[0049] Preferably, the polyisocyanate includes one or more of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and naphthalene-1,5-diisocyanate (NDI).

[0050] The technical solution described in this application will be explained in detail below with reference to specific embodiments:

[0051] Example 1

[0052] Weigh 160-mesh Chlorella powder and add it to deionized water under mechanical stirring to prepare an aqueous dispersion with a powder mass fraction of 10%. Dissolve at 2 mg / mL. -1 Polyethylene glycol with a molecular weight of 2000 was weighed and added to the dispersion under mechanical stirring. The dispersion was heated to 60°C and reacted at this temperature for 3 hours. Then, it was placed in a 100°C oven and dried for 48 hours to obtain solidified algal powder aggregates. The algal powder aggregates were ground into powder using a pulverizer to obtain polyethylene glycol 2000 modified Chlorella powder.

[0053] 100 parts of polyether polyol (VORANOL) TM REN 3535 was added to mixing tank A under mechanical stirring, along with 2 parts of pentafluorobutane foaming agent, 1 part of ethylenediamine crosslinking agent, 1 part of triethylenediamine, 0.05 parts of stannous octoate, and 0.7 parts of stabilizer β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester. After stirring evenly, 1% by volume of modified Chlorella powder was added. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a 1:1 ratio through a nozzle. The mixture was then reacted at 95°C for 3 minutes to obtain bioplastic-reinforced polyurethane foam.

[0054] Example 2

[0055] Weigh 80-mesh spirulina powder and add it to deionized water under mechanical stirring to prepare an aqueous dispersion with a 10% (w / w) spirulina powder content. Dissolve at 5 mg / mL. -1 Polyethylene glycol with a molecular weight of 1000 was weighed and added to the dispersion under mechanical stirring. The dispersion was heated to 50°C and reacted at this temperature for 2 hours. Then, it was placed in an oven at 80°C and dried for 72 hours to obtain solidified algal powder aggregates. The algal powder aggregates were ground into powder using a pulverizer to obtain spirulina powder modified with polyethylene glycol 1000.

[0056] 100 parts of polyether polyol (VORANOL) TM REN 3535 was added to mixing tank A under mechanical stirring, along with 4 parts pentafluorobutane foaming agent, 7 parts ethylenediamine crosslinking agent, 2 parts triethylenediamine, 0.05 parts stannous octoate, and 0.8 parts β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester stabilizer. After stirring evenly, 1.6% by volume of modified spirulina powder was added. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a ratio of 1.6:1 through a nozzle. The mixture was reacted at 95°C for 3 minutes to obtain bioplastic-reinforced polyurethane foam.

[0057] See Figure 1This is the X-ray diffraction pattern of spirulina powder modified with polyethylene glycol 1000 prepared using the process described in Example 2; the X-ray diffraction pattern of the raw spirulina powder was used as a control. Compared with the raw spirulina, the α-helical structure of the protein in the polyethylene glycol 1000 modified spirulina powder was significantly reduced while the β-sheet fold structure was significantly increased. The increase in β-sheet folds can effectively improve the shear strength and surface free hydrogen bond concentration of the protein material. The X-ray diffraction pattern testing method is as follows: Weigh 5 mg of bioplastic or 5 mg of 80-mesh spirulina powder, fill it into the groove of the glass sample holder, press the powder firmly with a glass slide, and scrape off any excess powder above the sample holder. Place the sample holder on the sample stage of the X-ray diffractometer (Rigaku XRD Intelligent X-ray Polycrystalline Diffractometer, Japan), and scan at a speed of 5° per minute within the range of 5°-90°.

[0058] See Figure 2 The Fourier transform infrared spectrum (FTIR) of the polyethylene glycol 1000-modified spirulina powder prepared using the process described in Example 2 is shown below; the FTIR spectrum of the raw spirulina powder is used as a control. Compared to the raw spirulina powder, the FTIR spectrum of the polyethylene glycol 1000-modified spirulina powder shows a higher concentration of hydrogen-bonded hydroxyl groups (3300-3400 cm⁻¹). -1 The intensity decreased significantly, indicating a significant increase in the number of free hydrogen bonds between molecules. The Fourier transform infrared spectroscopy (FTIR) test method is as follows: Weigh 5 mg of bioplastic or 5 mg of 80-mesh spirulina powder, place it on the sample stage of the attenuated total reflectance (ATR) device of the Fourier transform infrared spectrometer (Nicolet iS10 thermoelectric infrared spectrometer from the United States) and cover the sampling area. The sample is then analyzed at a depth of 16 cm⁻¹. -1 At a resolution of 400 cm⁻¹ and a sampling rate of 65 spectra / second, -1 Up to 4000cm -1 Infrared spectra of samples were collected within the wavenumber range.

[0059] See Figure 3 This is the stress-strain curve of the bioplastic-reinforced polyurethane foam prepared using the process described in this embodiment; polyurethane foam with and without spirulina powder added under the same process conditions was used as an experimental control. The stress-strain curve was tested according to ASTM D3574 Test E standard, and the slope of the obtained stress-strain curve is the Young's modulus of the sample.

[0060] Comparative Example 1

[0061] Preparation process of polyurethane foam with added spirulina powder. 100 parts of polyether polyol (VORANOL) are added... TMREN3535 was added to mixing tank A under mechanical stirring, along with 4 parts pentafluorobutane foaming agent, 7 parts ethylenediamine crosslinking agent, 2 parts triethylenediamine, 0.05 parts stannous octoate, and 0.8 parts β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester stabilizer. After stirring evenly, 1.6% by volume of 80-mesh spirulina powder was added. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a ratio of 1.6:1 through a nozzle. The mixture was then reacted at 95°C for 3 minutes to obtain polyurethane foam with added spirulina powder.

[0062] Comparative Example 2

[0063] Preparation process of polyurethane foam without added algae powder. 100 parts of polyether polyol (VORANOL) are added... TM REN3535 was added to mixing tank A under mechanical stirring, along with 4 parts pentafluorobutane foaming agent, 7 parts ethylenediamine crosslinking agent, 2 parts triethylenediamine, 0.05 parts stannous octoate, and 0.8 parts octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate stabilizer. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a ratio of 1.6:1 through a nozzle. The mixture was then reacted at 95°C for 3 minutes to obtain polyurethane foam without added algae powder.

[0064] See Figure 4 This document presents the compression-resilience stress-strain curve and energy absorption histogram of the bioplastic-reinforced polyurethane foam prepared using the process described in this embodiment. Polyurethane foam with and without spirulina powder, prepared under the same processing conditions, serves as a control. The compression-resilience stress-strain curve was tested according to ASTM D1056 with a compression rate of 80%; the compression-resilience stress was tested according to ASTM D1056 with a compression rate of 25%. The energy absorption capacity of the sample is the integral area of ​​the compression-resilience stress-strain curve below 65% compression.

[0065] See Table 1, which compares the mechanical and impact resistance properties of the bioplastic-reinforced polyurethane foam prepared using the process of this embodiment with those of polyurethane foam prepared under the same process conditions with and without spirulina powder. The impact transmission test standard refers to EN1621-1.

[0066] Table 1

[0067]

[0068] Example 3

[0069] Weigh 120-mesh seaweed powder and add it to deionized water under mechanical stirring to prepare an aqueous dispersion with a seaweed powder mass fraction of 15%. Dissolve at 10 mg / mL. -1 An epoxy resin with a molecular weight of 850 was weighed and added to a dispersion under mechanical stirring. The dispersion was heated to 80°C and reacted at this temperature for 2 hours. Then, it was dried in an 80°C oven for 64 hours to obtain a solidified algal powder aggregate. The algal powder aggregate was ground into powder using a pulverizer to obtain epoxy resin modified seaweed powder.

[0070] 100 parts of polyether polyol (VORANOL) TM REN 3535 was added to mixing tank A under mechanical stirring, along with 5 parts pentafluoropropane foaming agent, 5 parts N,N-dimethylhexadecanylamine crosslinking agent, 2 parts triethylenediamine, 0.06 parts dibutyltin dilaurate, and 1 part pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] stabilizer. After stirring evenly, 3% by volume of modified seaweed powder was added. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a 2:1 ratio through a nozzle. The mixture was then reacted at 95°C for 3 minutes to obtain bioplastic-reinforced polyurethane foam.

[0071] Example 4

[0072] Weigh 40-mesh giant kelp powder and add it to deionized water under mechanical stirring to prepare an aqueous dispersion with a 5% (w / w) kelp powder content. Dissolve at 15 mg / mL. -1 Castor oil with a molecular weight of 930 was weighed and added to the dispersion under mechanical stirring. The dispersion was heated to 60°C and reacted at this temperature for 2 hours. Then, it was placed in an oven at 80°C and dried for 80 hours to obtain solidified algal powder aggregates. The algal powder aggregates were ground into powder using a pulverizer to obtain castor oil-modified giant kelp powder.

[0073] 100 parts of polyether polyol (VORANOL) TM REN 3535 was added to mixing tank A under mechanical stirring, along with 3 parts of n-pentane foaming agent, 6 parts of N,N-dimethylhexadecanylamine crosslinking agent, 2 parts of triethylenediamine, 0.07 parts of bismuth isooctanoate, and 1 part of polycarbodiimide stabilizer. After thorough mixing, 1.8% by volume of modified giant kelp powder was added. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a 4:1 ratio through a nozzle. The mixture was then reacted at 95°C for 3 minutes to obtain bioplastic-reinforced polyurethane foam.

[0074] Example 5

[0075] Weigh 60-mesh *Microcystis aeruginosa* powder and add it to deionized water under mechanical stirring to prepare an aqueous dispersion with a powder mass fraction of 15%. Dissolve at 20 mg / mL. -1 Polyethylene glycol with a molecular weight of 1500 was weighed and added to the dispersion under mechanical stirring. The dispersion was heated to 60°C and reacted at this temperature for 2 hours. Then, it was placed in an oven at 80°C and dried for 64 hours to obtain solidified algal powder aggregates. The algal powder aggregates were ground into powder using a pulverizer to obtain polyethylene glycol 1500 modified microalgae powder.

[0076] 100 parts of polyether polyol (VORANOL) TM REN 3535 was added to mixing tank A under mechanical stirring, along with 3 parts pentafluoropropane foaming agent, 6 parts ethylenediamine crosslinking agent, 1.5 parts triethylenediamine, 0.07 parts bismuth neodecanoate, and 1 part monocarbodiimide stabilizer. After thorough mixing, 2% by volume of modified microalgae powder was added. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a 3:1 ratio through a nozzle. The mixture was then reacted at 95°C for 3 minutes to obtain bioplastic-reinforced polyurethane foam.

[0077] Example 6

[0078] Weigh 80-mesh spirulina powder and add it to deionized water under mechanical stirring to prepare an aqueous dispersion with a 10% (w / w) spirulina powder content. Dissolve at 5 mg / mL. -1 Polyethylene glycol with a molecular weight of 1000 was weighed and added to the dispersion under mechanical stirring. The dispersion was heated to 50°C and reacted at this temperature for 2 hours. Then, it was placed in an oven at 80°C and dried for 72 hours to obtain solidified algal powder aggregates. The algal powder aggregates were ground into powder using a pulverizer to obtain spirulina powder modified with polyethylene glycol 1000.

[0079] 100 parts of polyether polyol (VORANOL) TM REN 3535 was added to mixing tank A under mechanical stirring, along with 5 parts pentafluorobutane foaming agent, 7 parts ethylenediamine crosslinking agent, 2 parts triethylenediamine, 0.05 parts stannous octoate, and 1 part polycarbodiimide stabilizer. After thorough mixing, 3% by volume of modified spirulina powder was added. MDI was added to mixing tank B, and a precision metering pump was started to pour the materials from mixing tanks A and B into a mold at a 2:1 ratio through a nozzle. The mixture was then reacted at 95°C for 3 minutes to obtain bioplastic-reinforced polyurethane foam.

[0080] See Figure 5This is a scanning electron microscope (SEM) image of the bioplastic prepared using the process described in Example 2; an SEM image of spirulina powder was used as a control. It can be seen that, compared to spirulina, the bioplastic has a more angular particle morphology. The SEM image testing method is as follows: 1 mg of bioplastic or 1 mg of 80-mesh spirulina powder was weighed, the spirulina powder was spread evenly and fixed onto the aluminum sample stage of the SEM using conductive carbon adhesive, the surface of the powder was gold-plated using an ion sputtering apparatus, and its microstructure was observed using a SEM (Hitachi Regulus 8100).

[0081] See Figure 6 This is a dynamic light scattering particle size distribution map of the bioplastic prepared using the process in Example 2 of this paper; the dynamic light scattering particle size distribution map of spirulina powder raw material is used as an experimental control. It can be seen that, compared with spirulina powder raw material, the bioplastic has a uniform particle size distribution in aqueous solution. The test method for dynamic light scattering particle size distribution is as follows: the bioplastic or 80-mesh spirulina powder is dispersed in deionized water using ultrasonic dispersion to prepare a concentration of 1 mg / mL. -1 The dispersion was prepared. The dispersion was transferred to a cuvette and placed in the sample holder of the dynamic light scattering instrument (Malvin ZS90). The instrument was started and the dynamic light scattering particle size distribution map of the sample was obtained.

[0082] See Figure 7 The image shows a scanning electron microscope (SEM) image of the bioplastic-reinforced polyurethane foam prepared using the process described in Example 2. An SEM image of polyurethane foam with added spirulina powder was used as a control. It can be seen that, compared to polyurethane foam with added spirulina powder, the bioplastic-reinforced polyurethane foam has a smoother and more even surface structure.

[0083] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a bio-plastic reinforced polyurethane foam, characterized in that, The method comprises the following steps: dispersing the microalgae powder in deionized water under mechanical stirring to obtain a microalgae powder dispersion; adding a polyol to the microalgae powder dispersion under mechanical stirring, stirring for 10-15 minutes, heating to 50-80℃, and reacting at the temperature for 2-6 hours to obtain a polyol-modified microalgae powder dispersion; drying the polyol-modified microalgae powder dispersion in an oven at 60-100℃ for 48-120 hours, collecting the solid product and grinding it into powder using a pulverizer to obtain a polyol-modified microalgae powder; adding the polyol-modified microalgae powder, a catalyst, a blowing agent, and a stabilizer to the polyether polyol under mechanical stirring, and continuously stirring for 0.5-1 hour to obtain a polyol mixture; mixing the polyol mixture and a polyisocyanate in a ratio of 1:1-4:1 under mechanical stirring, and pouring the mixture into a mold to foam and form at 60-100℃ to obtain a bio-plastic-reinforced polyurethane foam material; The microalgae powder is spirulina powder, the particle size of the microalgae powder is 40-160 mesh; the polyol is polyethylene glycol, the molecular weight of the polyol is 800-2000, and the added concentration is 2 mg / mL -1 -20 mg / mL -1 .

2. The method for preparing bioplastic-reinforced polyurethane foam according to claim 1, characterized in that, the catalyst comprises one or more of ethylenediamine, N,N-dimethylhexadecylamine, trimethylenediamine, bismuth isooctoate, bismuth neodecanoate, stannous octoate, and dibutyltin dilaurate.

3. The method for preparing bioplastic-reinforced polyurethane foam according to claim 1, characterized in that, the blowing agent comprises one or more of water, cyclopentane, n-pentane, isopentane, pentafluoropropane, and pentafluorobutane.

4. The method for preparing bioplastic-reinforced polyurethane foam according to claim 1, characterized in that, the stabilizer comprises one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester, polycarbodiimide, and monocarbodiimide.

5. The method for preparing bioplastic-reinforced polyurethane foam according to claim 1, characterized in that, the volume fraction of the modified microalgae powder is 0.2%-6.4%.

6. The method for preparing bioplastic-reinforced polyurethane foam according to claim 1, characterized in that, the polyisocyanate comprises one or more of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and naphthalene-1,5-diisocyanate (NDI).

7. A bioplastic reinforced polyurethane foam, characterized in that, The bio-plastic-reinforced polyurethane foam is prepared by the method of any one of claims 1-6.

8. The bioplastic reinforced polyurethane foam according to claim 7, wherein, The Young's modulus of the bio-plastic reinforced polyurethane foam is 0.2-0.3 MPa, the compression resilience stress at 25% compression rate is 70-180 kPa, and the energy absorption capacity is 10.8 x 10 4 J m -3 .

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