Modified polyurethane sponge filler and preparation method thereof

Abstract

The invention provides a modified polyurethane sponge filler and a preparation method thereof. The filler is composed of 100 parts of polyether polyol, 5-20 parts of charcoal, 5-20 parts of diatomite, 2-10 parts of zinc oxide, 40-80 parts of isocyanate, 2-6 parts of a foaming agent, 0.5-2 parts of a catalyst and 1-3 parts of a foam stabilizer. The preparation process comprises the following steps: firstly, pretreating the charcoal and the diatomite, carrying out silane coupling agent surface modification on the zinc oxide, then mixing the modified components with the polyether polyol, and then adding aids such as isocyanate and the like for foaming and forming. Through the synergistic effect of the biochar, the diatomite and the zinc oxide, the specific surface area, the surface roughness and the hydrophilicity of the obtained filler are remarkably improved while good mechanical properties are maintained, so that the microbial adhesion ability is enhanced, and the preparation process is simple, environmentally friendly and economical.

Description

Technical Field

[0001] The present invention relates to a modified polyurethane sponge filler and a preparation method thereof, in particular to a polyurethane sponge filler modified by composite materials such as biochar, diatomaceous earth and zinc oxide, and belongs to the field of material science and engineering technology. Background Art

[0002] As a common porous material, polyurethane sponge is widely used in water treatment, biological fermentation and other fields. However, traditional polyurethane sponge fillers have problems such as poor surface hydrophilicity, low biocompatibility, and weak microbial attachment ability, which limit their application in biological treatment systems. In order to improve the performance of polyurethane sponge, existing research has established different modification methods. For example, by adding inorganic particles such as activated carbon, silica and other materials, the specific surface area and adsorption performance of the filler are increased; or hydrophilic groups are introduced through methods such as chemical grafting to improve the surface hydrophilicity of the material. However, these methods often have problems such as limited modification effect and complex process. Therefore, it is of great practical significance to develop a simple, effective, efficient and stable method for modifying polyurethane sponge fillers. Summary of the Invention

[0003] The purpose of the present invention is to provide a modified polyurethane sponge filler and a preparation method thereof, which significantly improves the surface properties, biocompatibility and microbial adhesion ability of the filler by introducing composite materials such as biochar, diatomaceous earth and zinc oxide into a polyurethane matrix while maintaining good mechanical properties.

[0004] The present invention is achieved through the following technical solutions:

[0005] A modified polyurethane sponge filler comprises the following components: polyether polyol, biochar, diatomaceous earth, zinc oxide, isocyanate, a foaming agent, a catalyst and a foam stabilizer.

[0006] It is further defined that the components are calculated in parts by weight as follows: 100 parts of polyether polyol, 5-20 parts of biochar, 5-20 parts of diatomaceous earth, 2-10 parts of zinc oxide, 40-80 parts of isocyanate, 2-6 parts of foaming agent, 0.5-2 parts of catalyst and 1-3 parts of foam stabilizer.

[0007] It is further defined that the biochar is obtained by carbonizing biomass at 400-600° C. for 2-4 hours under a nitrogen atmosphere, and has a particle size of 50-200 mesh.

[0008] It is further defined that the diatomaceous earth is obtained by acid treatment and high-temperature calcination of natural diatomaceous earth, and has a particle size of 10-100 μm.

[0009] It is further defined that the zinc oxide is nano-scale zinc oxide with a particle size of 20-100 nm.

[0010] It is further defined that the isocyanate is one or both of toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

[0011] It is further defined that the foaming agent is one or both of water and dichloromethane.

[0012] It is further defined that the catalyst is one or both of dibutyltin dilaurate and triethylenediamine.

[0013] It is further defined that the foam stabilizer is a silicone oil surfactant.

[0014] A method for preparing a modified polyurethane sponge filler comprises the following steps:

[0015] Biochar pretreatment: The biochar was dried at 105 °C for 24 h to remove moisture; then placed in a muffle furnace and calcined at 300 °C for 2 h to remove surface impurities.

[0016] Diatomaceous earth pretreatment: add diatomaceous earth to 2 mol / L hydrochloric acid solution, stir at 80°C for 2 hours, filter, and wash with water until neutral; then calcine at 600°C for 3 hours and grind to a particle size of 10-100 μm.

[0017] Surface modification of zinc oxide: zinc oxide nanoparticles were added to an ethanol solution containing 2 wt% of a silane coupling agent, KH550, and ultrasonically dispersed for 1 hour. The mixture was filtered and dried to obtain surface-modified zinc oxide.

[0018] Preparation of the mixed material: heat the polyether polyol to 60-80° C., add the pretreated biochar, diatomaceous earth and surface-modified zinc oxide in sequence, and mix them at a stirring speed of 300-500 r / min for 30-60 minutes to obtain a mixed material.

[0019] Foaming molding: add isocyanate, blowing agent, catalyst and foam stabilizer to the mixture in sequence, and stir quickly and evenly (stirring speed 1500-3000r / min, stirring time 10-30 seconds); then pour into a mold, foam and mold at room temperature, and then mature at 60-80℃ for 2-4 hours to obtain modified polyurethane sponge filler.

[0020] The beneficial effects of the present invention are:

[0021] This modified polyurethane sponge filler and its preparation method significantly enhance the filler's specific surface area, surface roughness, and hydrophilicity by introducing three materials—biochar, diatomaceous earth, and zinc oxide—into a polyurethane matrix. The biochar provides a porous structure and adsorption properties, the diatomaceous earth increases surface roughness and porosity, and the zinc oxide improves hydrophilicity and antibacterial properties. The modified filler's surface properties are significantly improved, with microbial attachment increasing by 50-100% compared to traditional polyurethane sponge fillers and biofilm formation time shortened by 30-50%. By controlling the amount and particle size of the composite material, the filler's performance is enhanced while maintaining good mechanical strength and elasticity, with tensile strength increased by 10-30% compared to traditional fillers. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 : Comparison of tensile strength of polyurethane filler under different implementation cases.

[0023] Figure 2 : Comparison of specific surface areas of polyurethane fillers under different implementation cases.

[0024] Figure 3 : Comparison of contact angles of polyurethane fillers under different implementation cases.

[0025] Figure 4 : Comparison of the amount of microorganisms attached to the surface of polyurethane filler under different implementation cases. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0027] Example 1

[0028] Biochar pretreatment: The bamboo charcoal was dried at 105 °C for 24 h, then placed in a muffle furnace, calcined at 300 °C for 2 h, and ground to 100 mesh.

[0029] Diatomaceous earth pretreatment: add diatomaceous earth to 2 mol / L hydrochloric acid solution, stir at 80°C for 2 hours, filter, and wash with water until neutral; then calcine at 600°C for 3 hours and grind to a particle size of 50 μm.

[0030] Surface modification of zinc oxide: 10 g of zinc oxide nanoparticles (particle size 50 nm) were added to an ethanol solution containing 2 wt % of silane coupling agent KH550, ultrasonically dispersed for 1 hour, filtered, and dried.

[0031] Preparation of the mixture: 100 g of polyether polyol (hydroxyl value 56 mgKOH / g) was heated to 70°C, and 10 g of pretreated biochar, 10 g of pretreated diatomaceous earth and 5 g of surface-modified zinc oxide were added in sequence, and mixed at a stirring speed of 400 r / min for 45 minutes.

[0032] Foaming molding: Add 60g toluene diisocyanate (TDI), 4g deionized water (foaming agent), 1g dibutyltin dilaurate (catalyst) and 2g silicone oil (foam stabilizer) to the mixture in sequence, and stir quickly and evenly (stirring speed 2000r / min, stirring time 20 seconds); then pour into a mold, foam and mold at room temperature, and then mature at 70°C for 3 hours to obtain a modified polyurethane sponge filler.

[0033] Example 2

[0034] The difference from Example 1 is that:

[0035] The amount of biochar added was 15 g, and the amount of diatomaceous earth added was 5 g;

[0036] The amount of zinc oxide added is 8g;

[0037] As the isocyanate, diphenylmethane diisocyanate (MDI) was used.

[0038] Example 3

[0039] The difference from Example 1 is that:

[0040] The amount of biochar added was 5 g, and the amount of diatomaceous earth added was 15 g;

[0041] The amount of zinc oxide added is 3g;

[0042] The hydroxyl value of the polyether polyol is 42 mgKOH / g.

[0043] Comparative Example

[0044] Preparation of ordinary polyurethane sponge filler: 100g of polyether polyol (hydroxyl value 56mgKOH / g) is heated to 70°C, 60g of toluene diisocyanate (TDI) is added, and the mixture is stirred for reaction for 1 hour; then 4g of deionized water (foaming agent), 1g of dibutyltin dilaurate (catalyst) and 2g of silicone oil (foam stabilizer) are added in sequence, and the mixture is rapidly stirred evenly (stirring speed 2000r / min, stirring time 20 seconds); the mixture is poured into a mold, foamed and formed at room temperature, and then aged at 70°C for 3 hours to obtain ordinary polyurethane sponge filler.

[0045] Performance Testing

[0046] Physical properties testing

[0047] Density: According to GB / T 6343-2009 standard test, the density of Examples 1-3 is 32 kg / m 3 、34kg / m 3 、30kg / m 3 The density of the comparative example is 31kg / m3 .

[0048] Porosity: tested by mercury intrusion porosimetry, the porosities of Examples 1-3 were 92%, 90%, and 93%, respectively, and the porosity of the comparative example was 88%.

[0049] Tensile strength: tested according to GB / T 6344-2008 standard, the tensile strengths of Examples 1-3 were 0.28 MPa, 0.30 MPa, and 0.26 MPa, respectively, and the tensile strength of the comparative example was 0.22 MPa.

[0050] Surface performance test

[0051] Contact angle: tested with a contact angle meter, the contact angles of Examples 1-3 were 58°, 55°, and 60°, respectively, and the contact angle of the comparative example was 85°.

[0052] Specific surface area: tested by BET method, the specific surface areas of Examples 1-3 were 12.5m 2 / g, 13.8m 2 / g, 11.2m 2 / g, the specific surface area of ​​the comparative example is 5.6m 2 / g.

[0053] Microbial adhesion performance test

[0054] After the filler was placed in activated sludge and cultured for 7 days, the biomass on the filler surface was measured. The biomass of Examples 1-3 was 12.5 g / m 2 , 14.2g / m 2 、11.8g / m 2 The biomass of the comparative example is 6.8g / m 2 .

[0055] in conclusion

[0056] From the above performance test results, it can be seen that the modified polyurethane sponge filler of the present invention is comparable to ordinary polyurethane sponge filler in terms of physical properties such as density, porosity, and tensile strength, but has significantly improved surface hydrophilicity, specific surface area, and microbial attachment capacity. In particular, Example 2, its biomass reached 14.2 g / m 2 , which is more than twice that of the control example, indicating that the modification method of the present invention can effectively improve the performance of the polyurethane sponge filler.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A modified polyurethane sponge filler, characterized in that: The composition includes the following: polyether polyol, biochar, diatomaceous earth, zinc oxide, isocyanate, foaming agent, catalyst and foam stabilizer.

2. A modified polyurethane sponge filler according to claim 1, characterized in that: The components are calculated in parts by weight as follows: 100 parts of polyether polyol, 5-20 parts of biochar, 5-20 parts of diatomaceous earth, 2-10 parts of zinc oxide, 40-80 parts of isocyanate, 2-6 parts of foaming agent, 0.5-2 parts of catalyst and 1-3 parts of foam stabilizer.

3. The modified polyurethane sponge filler according to claim 1, characterized in that: The biochar is prepared by carbonizing biomass at 400-600° C. for 2-4 hours under a nitrogen atmosphere, and has a particle size of 50-200 meshes.

4. The modified polyurethane sponge filler according to claim 1, characterized in that: The diatomaceous earth is obtained by acid treatment and high-temperature calcination of natural diatomaceous earth, and has a particle size of 10-100 μm.

5. The modified polyurethane sponge filler according to claim 1, characterized in that: The zinc oxide is nano-scale zinc oxide with a particle size of 20-100 nm.

6. The modified polyurethane sponge filler according to claim 1, characterized in that: The isocyanate is one or both of toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

7. The modified polyurethane sponge filler according to claim 1, characterized in that: The foaming agent is one or both of water and dichloromethane.

8. The modified polyurethane sponge filler according to claim 1, characterized in that: The catalyst is one or both of dibutyltin dilaurate and triethylenediamine.

9. The modified polyurethane sponge filler according to claim 1, characterized in that: The foam stabilizer is a silicone oil surfactant.

10. A method for preparing a modified polyurethane sponge filler according to any one of claims 1 to 9, characterized in that: The following steps are involved: Biochar pretreatment: The biochar was dried at 105 °C for 24 h to remove moisture; Then, it was placed in a muffle furnace and calcined at 300 °C for 2 h to remove surface impurities; Diatomaceous earth pretreatment: Add diatomaceous earth to 2 mol / L hydrochloric acid solution, stir at 80 ° C for 2 hours, filter and wash with water until neutral; Then, it was calcined at 600 °C for 3 h and ground to a particle size of 10-100 μm; Surface modification of zinc oxide: zinc oxide nanoparticles were added to an ethanol solution containing 2 wt% of a silane coupling agent, KH550, and ultrasonically dispersed for 1 hour. The mixture was filtered and dried to obtain surface-modified zinc oxide. Preparation of the mixed material: heat the polyether polyol to 60-80° C., add the pretreated biochar, diatomaceous earth and surface-modified zinc oxide in sequence, and mix at a stirring speed of 300-500 r / min for 30-60 minutes to obtain a mixed material; Foaming molding: add isocyanate, blowing agent, catalyst and foam stabilizer to the mixture in sequence, and stir quickly and evenly (stirring speed 1500-3000r / min, stirring time 10-30 seconds); then pour into a mold, foam and mold at room temperature, and then mature at 60-80℃ for 2-4 hours to obtain modified polyurethane sponge filler.

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