Preparation method of flame-retardant waterproof polyurethane foam material

Abstract

The invention discloses a preparation method of a flame-retardant waterproof polyurethane foam material, which comprises the following steps: firstly, fully mixing polyether polyol, ammonium polyphosphate, waste plastic runway powder and the like, then adding isocyanate, quickly stirring, and then pouring into a specific mold for foaming. And after foaming and forming, taking out and curing at room temperature to finally obtain the flame-retardant waterproof polyurethane foaming material. The waste plastic runway powder is used as the flame retardant aid, the waterproof agent and the reinforcing agent, so that the flame retardant property of the polyurethane foam is remarkably improved, the fire spreading speed is effectively reduced, the waterproof property of the material is also improved, and the durability and the stability of the polyurethane foam in a humid environment are improved. Meanwhile, recycling and utilization of the waste plastic track powder promote cyclic utilization of solid waste resources, and the concept of green and sustainable development is met.

Description

Technical Field

[0001] The invention belongs to the technical field of flame-retardant polyurethane, and in particular relates to a method for preparing a flame-retardant and waterproof polyurethane foam material. Background Art

[0002] Polyurethane foam is widely used in the construction industry, home appliance industry, automobile industry, etc. due to its advantages of light weight, light weight, thermal insulation, etc. However, polyurethane is flammable, which will pose a serious threat to the life safety of personnel and will also cause huge property losses. Therefore, it is very important to improve the flame retardant properties of polyurethane foam. By introducing main flame retardants and auxiliary flame retardants into polyurethane foam, the flame retardancy of polyurethane foam can be effectively improved. The main flame retardant includes ammonium polyphosphate, etc., and the auxiliary flame retardant includes pentaerythritol, melamine, etc. On the other hand, in the application process in the fields of construction, such as for exterior wall insulation, polyurethane foam is not only required to have excellent flame retardancy, but also good waterproofness to slow down the erosion of environmental water vapor on the building and extend its service life. To this end, it is necessary to add new waterproof substances to polyurethane foam, such as fluorocarbons, liquid paraffin, silicone oil, etc. Finally, polyurethane foam also needs to have sufficient compression strength to withstand certain external forces without large deformation and damage. In response to this demand, new reinforcing agents are often added to polyurethane foam. However, these practices will undoubtedly increase the complexity of the formula, increase costs and reduce product competitiveness. Therefore, it is necessary to develop a new technology and provide a new functional additive that can not only meet the flame retardant requirements of polyurethane foam and improve its waterproofness, but also play a reinforcing role. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for preparing a flame retardant and waterproof polyurethane foam material. The present invention utilizes waste plastic runway powder as an auxiliary flame retardant, waterproof agent and reinforcing agent, which not only significantly improves the flame retardant properties of polyurethane foam and effectively reduces the speed of fire spread, but also improves the waterproof performance of the material, and improves the durability and stability of polyurethane foam in a humid environment. In addition, the waste plastic runway powder also acts as a reinforcing agent, which significantly improves the compressive strength of polyurethane foam, enabling it to better play a role in the fields of construction, home appliances, automobiles, etc. The present invention uses waste plastic runway powder for polyurethane foam materials, which has significant economic and environmental benefits, promotes solid waste recycling and resource utilization, and practices the concept of green and sustainable development.

[0004] The method for preparing the flame-retardant and waterproof polyurethane foam material of the present invention comprises the following steps:

[0005] Step 1: Use a crusher to crush the waste plastic track, and then use water flotation to separate the crushed particles into light powder with a density less than water and heavy powder with a density greater than water. Put the light powder and heavy powder into a drying oven respectively to dry and remove moisture.

[0006] Step 2: Put the heavy powder, ammonium polyphosphate, pentaerythritol, ferric chloride, melamine and paraformaldehyde into a ball mill in proportion and mix them; mix and stir the ball-milled product with polyether polyol to obtain material A.

[0007] Step 3: Mix the light powder and isocyanate in a closed container to obtain material B.

[0008] Step 4: Add material B obtained in step 3 to material A, mix and stir quickly, then pour into the mold, foam into shape, and demold and solidify.

[0009] Furthermore, in step 1, the waste plastic track material comes from waste generated during the renovation of sports fields, playgrounds or pedestrian walkways, and is crushed and screened to form particles with a diameter of ≤150 μm.

[0010] Furthermore, in step 1, the drying temperature is 90° C. and the drying time is 12 h.

[0011] Furthermore, in steps 2 and 3, the amount of each raw material added is as follows by mass: 50 parts of polyether polyol, 50 parts of isocyanate, 10 parts of ammonium polyphosphate, 5 parts of pentaerythritol, 1-10 parts of heavy powder, 1-10 parts of light powder, 0.1-2 parts of ferric chloride, 5 parts of melamine, and 5 parts of paraformaldehyde.

[0012] Furthermore, in step 2, the ball-milled product and the polyether polyol are mixed and stirred at a temperature of 25° C., a stirring time of 2 h, and a stirring speed of 50 rpm.

[0013] Furthermore, in step 3, the light powder and isocyanate are mixed and stirred at a temperature of 25° C., a stirring speed of 100 rpm, and a stirring time of 30 min.

[0014] Furthermore, in step 4, the mixing time of material A and material B is 30 s, and the stirring speed is 500 rpm.

[0015] Furthermore, in step 4, the curing temperature is 25° C. and the curing time is 24 h.

[0016] According to the test results, the main components of light powder are organic polymers, including polyurethane and ethylene propylene rubber, etc.; the main components of heavy powder are inorganic substances coated with a small amount of organic matter, including calcium carbonate and silicon dioxide, etc. The light powder has a low density and can be suspended in the dispersion when mixed with low-viscosity isocyanate, instead of being easy to settle like the powder before screening; although the heavy powder has a high density, after ball milling with melamine / formaldehyde, it can form a melamine resin-coated powder structure, improving its dispersion uniformity in polyether polyols. In addition, the heavy powder contains calcium carbonate, etc., which will accelerate the decomposition and generate carbon dioxide in the presence of ferric chloride when it encounters fire and heat, playing a flame retardant role. The role of melamine / formaldehyde also includes the production of inert ammonia during the combustion process, which plays the role of a flame retardant.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] (1) The polyurethane foam material using waste plastic track powder as a functional additive has better flame retardancy, waterproofness and mechanical properties, effectively solving the problem of recycling and reusing waste plastic tracks and alleviating environmental pressure.

[0019] (2) The process design of the present invention disperses light powders containing organic compounds such as polyurethane and ethylene propylene rubber, and heavy powders containing calcium carbonate and silicon dioxide in isocyanate and polyether polyol respectively, eliminating the potential risk of uneven distribution of powders in the mixed system of isocyanate and polyether polyol. Specifically, the light powder has a low density and is not easy to settle when mixed with low-viscosity isocyanate. It has high dispersion uniformity and is significantly better than the mixed system of unscreened powder and isocyanate; the ball milling product of heavy powder and melamine / formaldehyde has good compatibility with polyether polyol and is evenly dispersed. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below in conjunction with specific embodiments, but the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. 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.

[0021] The discarded plastic track used in the present invention is taken from a breathable plastic track that needs to be dismantled and refurbished due to natural aging and wear, and its source is Henan Shengtian Sports Engineering Co., Ltd.

[0022] Embodiment 1:

[0023] This embodiment prepares a polyurethane foam material using waste plastic track powder as an auxiliary flame retardant according to the following steps:

[0024] 1. Use a pulverizer to crush the waste plastic track, and then use water flotation to separate the crushed particles into light powder with a density less than that of water and heavy powder with a density greater than that of water. Put the light and heavy powders into a drying oven with a preset temperature of 90°C for 12 hours to remove moisture;

[0025] 2. Put 2.5 parts of heavy powder, 10 parts of ammonium polyphosphate, 5 parts of pentaerythritol, 0.5 parts of ferric chloride, 5 parts of melamine and 5 parts of paraformaldehyde into a ball mill and mix for 2 hours at a speed of 50 rpm; put the ball-milled product into a container and mix and stir with 50 parts of polyether polyol for 30 minutes at a stirring speed of 100 rpm to obtain material A;

[0026] 3. Mix 2.5 parts of light powder with 50 parts of isocyanate in a closed container for 30 min at a stirring speed of 100 rpm to obtain material B;

[0027] 4. Add material B obtained in step 3 to material A, mix and stir quickly for 30 seconds at a stirring speed of 500 rpm; pour the mixed sample into the mold, demold after foaming, and cure at room temperature for 24 hours.

[0028] Embodiment 2:

[0029] This embodiment adopts the same method as that of Embodiment 1 to prepare a polyurethane foam material using waste plastic track powder as an auxiliary flame retardant, with the difference being that 2.5 parts of heavy powder and 2.5 parts of light powder are replaced with 5 parts of heavy powder and 5 parts of light powder respectively, and the remaining components and their amounts remain unchanged.

[0030] Embodiment 3:

[0031] This embodiment adopts the same method as that of Embodiment 1 to prepare a polyurethane foam material using waste plastic track powder as an auxiliary flame retardant, with the difference being that 2.5 parts of heavy powder and 2.5 parts of light powder are replaced by 10 parts of heavy powder and 10 parts of light powder, respectively, and the remaining components and their amounts remain unchanged.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0033] Comparative Example 1:

[0034] 1. Mix 50 parts of polyether polyol with 50 parts of isocyanate for 30 seconds at 25°C.

[0035] 2. Pour the mixture into a mold for foaming and cure at 25°C for 24 h.

[0036] Comparative Example 2:

[0037] 1. Use a pulverizer to crush the waste plastic track, and then use water flotation to separate the crushed particles into light powder with a density less than that of water and heavy powder with a density greater than that of water. Put the light powder and heavy powder into a drying oven with a preset temperature of 90°C for 12 hours to remove moisture;

[0038] 2. Put 2.5 parts of heavy powder into a ball mill and mix for 2 hours at a speed of 50 rpm; put the ball-milled product into a container and mix and stir with 50 parts of polyether polyol for 30 minutes at a stirring speed of 100 rpm to obtain material A;

[0039] 3. Mix 2.5 parts of light powder with 50 parts of isocyanate in a closed container for 30 minutes at a stirring speed of 100 rpm to obtain material B;

[0040] 4. Add material B obtained in step 3 to material A, mix and stir quickly for 30 seconds at a stirring speed of 500 rpm; pour the mixture into a mold for foaming, demold after foaming, and cure at 25°C for 24 hours.

[0041] Comparative Example 3:

[0042] 1. Put 10 parts of ammonium polyphosphate, 5 parts of pentaerythritol, 0.5 parts of ferric chloride, 5 parts of melamine and 5 parts of paraformaldehyde into a ball mill and mix for 2 hours at a speed of 50 rpm; put the ball-milled product into a container and mix and stir with 50 parts of polyether polyol for 30 minutes at a stirring speed of 100 rpm to obtain material A;

[0043] 2. Add 50 parts of isocyanate to material A obtained in step 1, mix and stir rapidly for 30 seconds at a stirring speed of 500 rpm; pour the mixture into a mold for foaming, demould after foaming, and cure at 25°C for 24 hours.

[0044]

[0045] The data in Table 1 show that, from Example 1 to Example 3, as the amount of waste plastic track powder increases, the limiting oxygen index continues to increase, which clearly shows that the waste plastic track powder is beneficial to improving the flame retardant properties of polyurethane foam.

[0046] Comparative Example 1 is pure polyurethane foam, the limiting oxygen index is only 19.22%, and it does not obtain UL-94 rating, indicating that polyurethane foam is very flammable. Comparative Example 2 is a polyurethane foam containing waste plastic runway powder but not ammonium polyphosphate, and the limiting oxygen index does not change significantly, indicating that waste plastic runway powder itself cannot improve the flame retardant properties of polyurethane foam. The results of Comparative Example 3 show that ammonium polyphosphate has a good flame retardant effect on polyurethane foam.

[0047] However, compared with Comparative Example 3, Example 2 adds waste plastic track powder on the basis of Comparative Example 3, and its limiting oxygen index is improved from 25.08% to 26.42%, indicating that waste plastic track powder can synergistically improve the flame retardant properties of polyurethane foam with ammonium polyphosphate and the like.

[0048] From Example 1 to Example 3, it can also be seen that under the condition of appropriate amount of waste plastic track powder, the compressive strength and water contact angle of polyurethane foam can reach the optimal level. Waste plastic track powder can be used as a multifunctional additive to improve the performance of polyurethane foam.

Claims

1. A method for preparing a flame retardant and waterproof polyurethane foam material, characterized in that The steps include: Step 1: Use a crusher to crush the waste plastic track, and then use water flotation to separate the crushed particles into light powder with a density less than water and heavy powder with a density greater than water; put the light powder and heavy powder into a drying oven respectively to dry and remove moisture; Step 2: Add the heavy powder, ammonium polyphosphate, pentaerythritol, ferric chloride, melamine and paraformaldehyde into a ball mill in proportion and mix them; mix the ball-milled product with polyether polyol to obtain material A; Step 3: Mix and stir the light powder and isocyanate in a closed container to obtain material B; Step 4: Add material B obtained in step 3 to material A, mix and stir quickly, then pour into the mold, foam into shape, and demold and solidify.

2. The preparation method according to claim 1, characterized in that: In step 1, the waste plastic track material is taken from the plastic track waste generated during the renovation of a sports field, a playground or a pedestrian walkway, and is crushed and sieved to form particles with a diameter of ≤150 μm.

3. The preparation method according to claim 1, characterized in that: In step 1, the drying temperature is 90°C and the drying time is 12 h.

4. The preparation method according to claim 1, characterized in that: In steps 2 and 3, the addition amount of each raw material is composed by mass: 50 parts of polyether polyol, 50 parts of isocyanate, 10 parts of ammonium polyphosphate, 5 parts of pentaerythritol, 1-10 parts of heavy powder, 1-10 parts of light powder, 0.1-2 parts of ferric chloride, 5 parts of melamine, and 5 parts of paraformaldehyde.

5. The preparation method according to claim 1, characterized in that: In step 2, the ball-milled product and the polyether polyol are mixed and stirred at a temperature of 25° C., a stirring time of 2 h, and a stirring speed of 50 rpm.

6. The preparation method according to claim 1, characterized in that: In step 3, the light powder and isocyanate are mixed and stirred at a temperature of 25° C., a stirring speed of 100 rpm, and a stirring time of 30 min.

7. The preparation method according to claim 1, characterized in that: In step 4, the mixing time of material A and material B is 30 s, and the stirring speed is 500 rpm.

8. The preparation method according to claim 1, characterized in that: In step 4, the curing temperature is 25°C and the curing time is 24 h.

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