Graphene modified polyurethane foam material for soilless culture and preparation method thereof

Abstract

The invention discloses a graphene modified polyurethane foam material for soilless culture and a preparation method thereof, and the graphene modified polyurethane foam material is prepared from the following raw materials in parts by mass: 20-40 parts of polyol, 25-30 parts of isocyanate, 0.1-2 parts of a tin catalyst, 0.1-2 parts of an amine catalyst, 10-30 parts of modified graphene slurry, 0.1-2 parts of a foam stabilizer, 1-2 parts of a pore opening agent and 1-3 parts of water. The modified graphene slurry is added in the sponge preparation process, and graphene is fixed on the sponge and can play a role in inhibiting growth of algae, so that the utilization rate of nutrient substances is increased, plant root system production is promoted, a nutrient substance transmission channel is not blocked, the efficiency of a circulating pump is kept, and the sponge is economical and reliable. Furthermore, according to the sponge prepared by the invention, the heat conduction and light conduction characteristics of graphene can be fully utilized, the growth of plants is promoted when crops are planted on the sponge, and the yield is increased.

Description

Technical Field

[0001] The invention belongs to the field of soilless cultivation, and particularly relates to a graphene-modified polyurethane foam material for soilless cultivation and a preparation method thereof. Background Art

[0002] With the human health problems caused by environmental deterioration, urban greening has become the key to sustainable ecological development. Soilless cultivation substrate is an alternative to soil cultivation for people. Planting sponge is a new type of cultivation substrate that has emerged in recent years. It is made of a mixture of polymer foaming materials and a certain proportion of organic or inorganic matter. It is used in the soilless cultivation industry. It is environmentally friendly, rich in nitrogen, and has acid and alkali resistance and water absorption capacity. It is an ideal nutrient solution storage material for soilless cultivation. Its planting advantages are: loose and breathable, good drainage performance, and can maintain the water-gas ratio required for plant growth; good water and fertilizer retention performance, which can reduce the number of irrigation and fertilization and reduce the difficulty of maintenance; it does not breed mosquitoes, is clean and hygienic, harmless and odorless, and does not contain harmful bacteria to the human body; it is light in weight, beautiful in appearance and highly plastic, and easy to use.

[0003] However, after long-term use, the above-mentioned matrix will cause algae enrichment due to eutrophication of the nutrient solution, which is specifically manifested in the appearance of a large number of green algae in the planting sponge and the circulating nutrient pool. On the one hand, it will reduce the utilization rate of nutrients, and on the other hand, it will affect the production of plant roots and block the nutrient transmission channel. In addition, it will affect the efficiency of the circulation pump, resulting in an increase in electricity consumption and operating costs.

[0004] Patent CN201911278139.1 discloses a polyether polyol for soilless culture polyurethane foam and its preparation method and soilless culture polyurethane foam and its preparation method, but the density is high and the material is heavy.

[0005] Patent CN201110343816.0 discloses a polyurethane foam material for soilless cultivation and a preparation method thereof, which can be self-biodegraded after a certain period of use and has environmental advantages, but has poor acid and alkali corrosion resistance and a short service life.

[0006] Patent CN201710997633.8 adds graphene to the liquid matrix, and uses the thermal conductivity and optical properties of graphene to improve the performance of indoor hydroponic plant culture solution to solve the problem of abnormal growth of hydroponic plants during indoor culture. However, the graphene flows into the culture solution, resulting in a large amount of graphene used, graphene enrichment problems, and easy clogging of the pores of the solid cultivation matrix, affecting the growth of plants.

[0007] Patent CN202211133583.6 discloses a graphene-based in-situ water purification method, which mentions that the adsorption sponge used in step 1 is added with a graphene oxide polyurethane sponge containing 1-3 thousandths of graphene oxide by mass ratio. However, the preparation method of the graphene oxide polyurethane sponge is not described in detail.

[0008] Patent CN202210101784.1 discloses a degradable nutrient plant growth sponge material and its preparation method. This product makes up for the shortcomings of ordinary soilless cultivation sponge materials, such as poor degradability, weak water absorption and retention capacity, and inability to provide nutrition to plants. Summary of the invention

[0009] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a sponge material containing graphene that can inhibit the growth of algae in water bodies and a preparation method thereof, thereby inhibiting the growth of algae through graphene and promoting the growth of plants by utilizing the thermal conductivity and optical properties of graphene.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] A graphene-modified polyurethane foam material for soilless cultivation, wherein the raw materials for its preparation include, by weight: 20-40 parts of polyol, 25-30 parts of isocyanate, 0.1-2 parts of tin catalyst, 0.1-2 parts of amine catalyst, 10-30 parts of modified graphene slurry, 0.1-2 parts of foam stabilizer, 1-2 parts of pore opener, and 1-3 parts of water;

[0012] Furthermore, the polyol includes polyester polyol and polyether polyol. The polyether polyol is polyether 330, polyether 210, polyether 220 or polyether 303; and the polyester polyol is polyester ps-2402.

[0013] Furthermore, isocyanate includes MDI and TDI.

[0014] Further, the tin catalyst is stannous isooctanoate or dibutyltin diosilicate;

[0015] Amine catalysts include triethylenediamine and triethanolamine.

[0016] Further, the foam stabilizer includes silicone oil.

[0017] Furthermore, the graphene slurry is a polyol dispersion of graphene prepared by an exfoliation method, wherein the content of graphene is 25 wt %, and the polyol used is the same as the polyol described in claim 1.

[0018] The present invention also discloses a method for preparing the graphene-modified polyurethane foam material for soilless cultivation, comprising the following steps:

[0019] (1) mixing a polyol, a tin catalyst, an amine catalyst, a modified graphene slurry, a pore opening agent, and water to form a component A;

[0020] Mix isocyanate and foam stabilizer to form component B;

[0021] (2) Stir component A and component B evenly at room temperature, use a polyurethane casting machine to mix components A and B, put the mixed solution in a mold, mature it at 20 to 35° C. for 10 to 30 minutes, and then cure it at room temperature for 48 to 72 hours to obtain the sponge material.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention fixes graphene on the sponge by adding modified graphene slurry during the sponge preparation process. The graphene can inhibit the growth of algae, thereby improving the utilization rate of nutrients, promoting plant root production, not blocking the nutrient transmission channel, maintaining the efficiency of the circulation pump, etc., and is economical and reliable. Furthermore, the sponge prepared by the present invention can make full use of the heat and light conduction properties of graphene, promote the growth of plants when crops are planted on the sponge, and increase the yield. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatus.

[0026] The present invention is described in further detail below:

[0027] Example 1

[0028] The raw materials for its preparation include component A and component B in parts by mass;

[0029] Component A includes: 20 parts of polyether 300 polyol, 0.01 parts of stannous isooctanoate, 0.07 parts of 33% triethylenediamine ethylene glycol solution, 30 parts of graphene slurry, 0.1 parts of silicone oil L-580, 1 part of pore opening agent, and 2 parts of water.

[0030] Component B includes: 35 parts of liquefied MDI and 0.1 parts of foam stabilizer.

[0031] At room temperature, components A and B are stirred evenly using a high-speed stirrer at a speed of 2000 rpm / min. Component A and component B are mixed, and stirred using a high-speed stirrer at 4000 rpm / min for 8-10 seconds until the solution turns white. The solution is placed in a polyvinyl chloride mold, and placed in an oven at 25°C for aging for 10 minutes. The mold is taken out and cured at room temperature for 48 hours to obtain a sponge material.

[0032] Embodiment 2-4

[0033] The same steps as in Example 1 were followed, except that the weight portions of the components were changed, as shown in Table 1, to prepare a graphene sponge material.

[0034] Table 1

[0035]

[0036] The prepared sponge material was used for soilless cultivation. The prepared sponge materials were taken and evaluated in the same field. The same vegetable, butter lettuce, was planted. The time of algae appearance, the number of water pump maintenance times and the change of electricity consumption in the whole planting cycle were investigated. A comparative analysis of each embodiment was conducted and listed in Table 2.

[0037] Comparative Examples 1-4 are simply obtained by removing the modified graphene slurry in Examples 1-4 and adding the polyol contained in the corresponding graphene slurry, and preparing the sponge material by referring to the raw material components in Table 1.

[0038] Table 2

[0039]

Claims

1. A graphene-modified polyurethane foam material for soilless cultivation, characterized in that: The raw materials for its preparation include, by weight: 20-40 parts of polyol, 25-30 parts of isocyanate, 0.1-2 parts of tin catalyst, 0.1-2 parts of amine catalyst, 10-30 parts of modified graphene slurry, 0.1-2 parts of foam stabilizer, 1-2 parts of pore opener and 1-3 parts of water.

2. The graphene-modified polyurethane foam material for soilless cultivation according to claim 1, characterized in that: The polyol includes polyester polyol and polyether polyol. The polyether polyol is polyether 330, polyether 210, polyether 220 or polyether 303; and the polyester polyol is polyester ps-2402.

3. The graphene-modified polyurethane foam material for soilless cultivation according to claim 1, characterized in that: Isocyanates include MDI and TDI.

4. The graphene-modified polyurethane foam material for soilless cultivation according to claim 1, characterized in that: The tin catalyst is stannous isooctanoate or dibutyltin diosilicate.

5. The graphene-modified polyurethane foam material for soilless cultivation according to claim 1, characterized in that: Amine catalysts include triethylenediamine and triethanolamine.

6. The graphene-modified polyurethane foam material for soilless cultivation according to claim 1, characterized in that: Foam stabilizers include silicone oil.

7. The graphene-modified polyurethane foam material for soilless cultivation according to claim 1, characterized in that: The graphene slurry is a polyol dispersion of graphene prepared by an exfoliation method, wherein the content of graphene is 25wt%, and the polyol used is the same as the polyol described in claim 1.

8. The method for preparing the graphene-modified polyurethane foam material for soilless cultivation according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) mixing polyol, tin catalyst, amine catalyst, modified graphene slurry and foam stabilizer to form component A; mixing isocyanate and tetraethyl orthosilicate to form component B; (2) Stir component A and component B evenly at room temperature, use a polyurethane casting machine to mix components A and B, put the mixed solution in a mold, mature it at 20 to 35° C. for 10 to 30 minutes, and then cure it at room temperature for 48 to 72 hours to obtain the sponge material.

9. The graphene-modified polyurethane foam material for soilless culture according to claims 1 to 7 is used to inhibit the growth of algae in water bodies.

10. The graphene-modified polyurethane foam material for soilless cultivation according to claims 1 to 7 is used to promote plant growth.

Images