Flame-retardant rigid polyurethane foam thermal insulation material and preparation method thereof

Abstract

The invention provides a flame-retardant rigid polyurethane foam thermal insulation material and a preparation method thereof, and belongs to the crossing field of solid waste resource utilization and halogen-free flame retardance. The thermal insulation material is prepared from the following raw materials in parts by mass: 10 to 50 parts of a rare earth metal organic framework material (M-MOF) grafted polydopamine modified steel slag flame retardant, 20 to 70 parts of a halogen-free flame retardant, 50 to 150 parts of polyol, 120 to 200 parts of polyisocyanate, 0.5 to 2 parts of an amine catalyst, 0.2 to 1 part of an organic tin catalyst, 0.5 to 5 parts of a chemical foaming agent and 5 to 50 parts of a physical foaming agent. And 0.5-3 parts of a foam stabilizer. Efficient flame retardance of the halogen-free flame retardant is achieved, the effects of synergistic flame retardance, smoke suppression, toxicity reduction and the like of the steel slag are achieved, high-value utilization of the steel slag is achieved, and the problems that a traditional rigid polyurethane foam thermal insulation material is high in preparation cost and low in fire safety performance are solved; the material can be widely applied to the fields of building exterior walls, cold-chain logistics, pipeline insulation and the like.

Description

Technical Field

[0001] The present invention belongs to the intersection field of solid waste resource utilization and halogen-free flame retardancy, and specifically relates to a polyurethane foam thermal insulation material, and in particular to a flame-retardant rigid polyurethane foam thermal insulation material prepared by grafting a rare earth metal organic framework material with a polydopamine-modified steel slag flame retardant and a halogen-free flame retardant. Background Art

[0002] As a new type of porous material, rigid polyurethane foam has been widely used in building insulation and other fields due to its controllable components, convenient construction, good thermal insulation performance, excellent aging resistance and other advantages. However, rigid polyurethane foam is very easy to burn. Once it burns, the fire spreads very quickly and releases a large amount of smoke particles and toxic gases, which can easily cause heavy casualties in the fire and cause great damage to the environment. Therefore, the industry often uses halogen-free flame retardants to modify rigid polyurethane foam to improve its flame retardant properties.

[0004] Polydopamine (PDA) is a biomass polymer formed by the self-polymerization of dopamine monomers in an alkaline environment. Studies have found that the surface of dopamine is rich in catechol groups and amino groups, which can synergistically promote the adhesion of PDA to almost all solid surfaces to form a functional surface coating, which makes PDA widely used in the field of material surface modification. In addition, the catechol groups can react with hydroxyl groups to form hydrogen bonds, and can complex with metal ions and non-metal ions to improve their compatibility with polymer matrices. At the same time, the quinones generated by the oxidation process can also interact with groups such as benzene rings through π-π bonds. Metal-organic framework materials (MOFs) have attracted much attention due to their advantages such as high specific surface area, high porosity and good crystallinity. In addition, the metal oxides generated by the thermal decomposition of the MOF structure have good catalytic carbonization ability and can effectively improve the compatibility of flame-retardant particles with polymer matrices. Rare earth metals are a general term for 17 elements in the scandium, yttrium and lanthanide series in the IIIB group of the periodic table. Rare earth metals have significant application prospects in the field of flame retardancy due to their good catalytic properties.

[0005] Steel slag is rich in metal oxides and non-metal oxides, with the main components being calcium oxide (CaO), silicon oxide (SiO2), aluminum oxide (Al2O3), and iron oxide (Fe2O3). It also contains a small amount of magnesium oxide (MgO) and zinc oxide (ZnO). If it is modified reasonably, it has the potential to become a flame retardant. Steel slag is modified using polydopamine (PDA), and PDA is used as a bridge to complex rare earth metal organic framework materials on the SS surface to prepare flame retardants. It is compounded with halogen-free flame retardants, and the flame retardant effect of polymer materials can be effectively improved through flame retardant synergy. At the same time, the active sites formed by the rare earth metal elements on the rare earth metal organic framework materials can effectively reduce the release of toxic gases such as CO during combustion through oxidation-reduction cycles.

[0006] At present, the application of rare earth metal organic framework grafted polydopamine modified steel slag flame retardant in polymer material products, especially rigid polyurethane foam in the fields of flame retardant synergy and smoke suppression and toxicity reduction is not yet mature, and the high-value utilization of steel slag needs to be further explored. Summary of the invention

[0007] The technical problem to be solved by the present invention is to address the technical bottlenecks of low efficiency of traditional halogen-free flame retardant rigid polyurethane foam, large amount of toxic smoke generated during combustion, large amount of steel slag accumulation, low added value, etc., and provide a flame retardant rigid polyurethane foam based on rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant and halogen-free flame retardant and a preparation method thereof, so that the prepared flame retardant rigid polyurethane foam insulation material has excellent flame retardant properties and smoke suppression and toxicity reduction properties, while realizing the high-value utilization of steel slag.

[0008] The present invention is achieved through the following technical solutions.

[0009] The present invention provides a flame retardant rigid polyurethane foam thermal insulation material. The raw materials for preparing the thermal insulation material are as follows in parts by mass:

[0010]

[0011] The amine catalyst is one or more of triethylamine, triethanolamine, pentamethyldiethylenetriamine (Polycat 5), N,N-dimethylcyclohexylamine (Polycat 8), tris(dimethylaminopropyl)amine (Polycat 9), tris(dimethylaminopropyl)hexahydrotriazine (Polycat 41), Dabco BL 11 (70% bis(dimethylaminoethyl) ether and 30% dipropylene glycol mixture), A33 (33wt% triethylenediamine).

[0012] The organic tin catalyst is one or more of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate.

[0013] The foam stabilizer is a silicone oil surfactant.

[0014] The rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant comprises:

[0015] 5-10 parts of polydopamine modified steel slag;

[0016] 1-2 parts of rare earth metal organic framework material;

[0017] 300-500 parts of anhydrous ethanol;

[0018] The polydopamine modified steel slag comprises:

[0019]

[0020] The rare earth metal organic framework material comprises:

[0021]

[0022] The chemical solvent is one or more of deionized water and anhydrous ethanol.

[0023] Furthermore, the halogen-free flame retardant is one or more of ammonium polyphosphate, piperazine pyrophosphate, aluminum hypophosphite, diethyl aluminum hypophosphite, and melamine polyphosphate.

[0024] Furthermore, the polyol is one or more of polyester polyol having a hydroxyl value of 300-500 mgKOH / g or polyether polyol having a hydroxyl value of 380-500 mgKOH / g.

[0025] Furthermore, the polyisocyanate is a polymethylene polyphenyl polyisocyanate having an NCO group mass percentage of 29.5-32.5 wt %.

[0026] Furthermore, the chemical foaming agent is one or more of purified water, dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate.

[0027] Furthermore, the physical foaming agent is one or more of cyclopentane, n-pentane, isopentane, butane, 1,1,1,2-tetrafluoroethane (HFC-134A), pentafluoropropane (HFC-245FA), pentafluorobutane (HFC-365MFC), heptafluoropropane (HFC-227EA), monofluorodichloroethane (HCFC-141B), trans-1-chloro-3,3,3-trifluoropropene (HFO-1233ZD), and 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336MZZ).

[0028] Furthermore, the rare earth metal organic framework material is one or more of cerium-metal organic framework material, scandium-metal organic framework material, neodymium-metal organic framework material, gadolinium-metal organic framework material, and yttrium-metal organic framework material.

[0029] Furthermore, the rare earth metal salt solution is one or more of cerium nitrate, scandium nitrate, neodymium nitrate, gadolinium nitrate, and yttrium nitrate.

[0030] The present invention also provides a method for preparing the flame retardant rigid polyurethane foam thermal insulation material, which specifically comprises the following steps:

[0031] Step S1 is the preparation of polydopamine modified steel slag: at room temperature, dopamine hydrochloride and steel slag are added to a reactor equipped with a stirrer, and dispersed in a chemical solvent, and then 1-30mmol / L tris(hydroxymethyl)aminomethane-hydrochloride buffer solution (Tris-HCl) is added, and the solution pH is adjusted to 6-10 with ammonia water and stirred at 100-500r / min for 24h. After the reaction is completed, the obtained mixed solution is centrifuged and dried to obtain polydopamine modified steel slag.

[0032] Step S2 is the preparation of rare earth metal organic framework material: under room temperature, a chemical solvent is added to a reactor equipped with a stirrer, and trimesic acid is added and stirred evenly at a temperature of 40-80°C; then 5.0-40.0wt% rare earth metal salt solution is added to the trimesic acid solution and stirred at a speed of 100-500r / min, and the obtained product is washed and dried to obtain a rare earth metal organic framework material.

[0033] Step S3 is the preparation of a rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant: under room temperature, polydopamine modified steel slag and rare earth metal organic framework material are added to a reactor equipped with a stirrer, dispersed in anhydrous ethanol, and stirred at a high speed of 100-500r / min at a temperature of 40-80°C for 6-36h; then, after centrifugation, washing and drying, the rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant is obtained.

[0034] Step S4 is the preparation of flame-retardant rigid polyurethane foam insulation material: under the condition of 25-30°C, polyol, amine catalyst, organic tin catalyst, chemical foaming agent, physical foaming agent, foam stabilizer, rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant, halogen-free flame retardant and polyisocyanate are added to the stirring device in sequence, and after high-speed stirring until uniform and wire drawing occurs, the mixture is injected into the mold for foaming. After the foam is formed, the foam is taken out and placed in an oven for maturation to obtain a flame-retardant rigid polyurethane foam insulation material.

[0035] Furthermore, in step S4, the stirring speed is 200-3500 r / min; the stirring time is 3-40 s; the aging temperature is 40-90° C.; and the aging time is 0.5-24 h.

[0036] The innovation of the present invention:

[0037] The present invention prepares a flame-retardant rigid polyurethane foam thermal insulation material by grafting polydopamine modified steel slag with a rare earth metal organic framework material (M-MOF), and combining it with a halogen-free flame retardant. The rare earth metal ions in the polydopamine modified steel slag grafted with the rare earth metal organic framework material (M-MOF), the metal oxides (CaO, Al2O3, Fe2O3) rich in the steel slag, the non-metallic oxide (SiO2) and the halogen-free flame retardant are promoted through synergistic catalysis to promote the thermal cross-linking reaction of the polyurethane molecular chain, reduce the generation of combustible gas, and form a dense graphitized carbon layer on the surface of the combustion area, preventing the transport of substances (oxygen, combustible gas) and heat in the combustion area, thereby playing a flame retardant role. The active sites of the rare earth metal elements on the M-MOF can effectively reduce the release of toxic gases such as CO during the combustion process through oxidation-reduction cycles.

[0038] Compared with the prior art, the present invention has the following technical effects:

[0039] 1. The rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant is prepared by grafting the amino group on the surface of polydopamine modified steel slag with the hydrogen bonding action of the carboxyl group on the surface of the rare earth metal organic framework material, effectively exerting its flame retardant synergistic effect, and significantly enhancing the flame retardant efficiency. Compared with pure rigid polyurethane foam, the rigid polyurethane foam added with the rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant has a limiting oxygen index greater than 24.5vol%, and the vertical combustion level is UL-94V-0 level.

[0040] 2. The problem of low flame retardant efficiency of traditional halogen-free flame retardants when added alone to rigid polyurethane foam is solved. Halogen-free flame retardants and rare earth metal organic framework grafted polydopamine modified steel slag flame retardants play a catalytic role in the rigid polyurethane foam matrix. Among them, the active sites formed by rare earth metal elements can effectively inhibit the production of toxic fumes such as CO during combustion through oxidation-reduction reaction cycles, and have obvious smoke suppression and toxicity reduction effects. The total CO production of rigid polyurethane foam added with rare earth metal organic framework grafted polydopamine modified steel slag flame retardant during combustion is reduced by more than 25% compared with pure rigid polyurethane foam.

[0041] 3. Through modification, steel slag is used as a green and environmentally friendly flame retardant synergist and smoke suppressant and toxic reducer for rigid polyurethane foam flame retardancy, further improving the added value of steel slag, realizing the high-value utilization of steel slag, turning waste into treasure, and protecting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a diagram of the preparation mechanism of the flame-retardant rigid polyurethane foam thermal insulation material of the present invention;

[0043] As can be seen from the figure, rare earth metal salt reacts with trimesic acid at 60°C to generate rare earth metal organic framework material; dopamine hydrochloride and steel slag are dispersed in a chemical solvent, stirred at a speed of 100-500r / min for 24 hours, and polydopamine modified steel slag is reacted; the rare earth metal organic framework material and polydopamine modified steel slag material obtained above are dispersed in anhydrous ethanol, and reacted at a temperature of 40-80°C and a high-speed stirring of 100-500r / min for 6-36 hours to obtain a rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant.

[0044] Figure 2 This is a scanning electron microscope photograph of the rare earth metal organic framework material grafted with polydopamine modified steel slag in Example 1 of the present invention; wherein a is a cerium-metal organic framework material, b is polydopamine modified steel slag, and c is a rare earth metal organic framework material grafted with polydopamine modified steel slag.

[0045] Figure 3 This is a graph showing the change in heat release rate over time of pure rigid polyurethane foam, flame retardant rigid polyurethane foam-1, flame retardant rigid polyurethane foam-2, and flame retardant rigid polyurethane foam-3 obtained by cone calorimetry test.

[0046] Figure 4 This is a curve chart showing the change in total smoke generation over time of pure rigid polyurethane foam, flame retardant rigid polyurethane foam-1, flame retardant rigid polyurethane foam-2, and flame retardant rigid polyurethane foam-3 obtained by cone calorimetry test. DETAILED DESCRIPTION

[0047] In order to further illustrate the technical solution of the present invention, the preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention. Based on the examples in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0048] Example 1

[0049] The flame-retardant rigid polyurethane foam of the halogen-free flame retardant prepared in this embodiment and its preparation method are to prepare polydopamine-modified steel slag by bio-based polydopamine, prepare rare earth metal organic framework material by coordination chemistry strategy, and then prepare rare earth metal organic framework material grafted polydopamine-modified steel slag flame retardant by grafting action between polydopamine-modified steel slag and rare earth metal organic framework material, and finally, the rare earth metal organic framework material grafted polydopamine-modified steel slag flame retardant, halogen-free flame retardant and polyol, amine catalyst, organotin catalyst, chemical foaming agent, physical foaming agent, foam stabilizer and polyisocyanate are stirred at high speed until wire drawing occurs, and the flame-retardant rigid polyurethane foam insulation material is prepared by aging in an oven. Among them, ammonium polyphosphate is selected as the halogen-free flame retardant, and cerium nitrate is selected as the metal salt used to prepare the rare earth metal organic framework, and the flame-retardant rigid polyurethane foam insulation material is prepared according to the following steps:

[0050] Step S1: At room temperature (20°C), weigh 0.5g dopamine hydrochloride and 10g steel slag into a 500mL three-necked flask, then add 250mL deionized water to dissolve the fixed drug, draw 2.5mL Tris-HCl buffer solution (10mmol / L) into the three-necked flask, adjust the pH to 8.5 with ammonia water, stir at 200r / min for 24h, and centrifuge three times with anhydrous ethanol and deionized water after the reaction. Then dry in a blast drying oven at 60°C to obtain polydopamine modified steel slag (SS@PDA).

[0051] Step S2: 40 mL of anhydrous ethanol and 40 mL of deionized water were transferred to a 500 mL three-necked flask, and 8.4 g of trimesic acid was added and stirred at 60° C. Subsequently, 180 mL of cerium nitrate (10 wt%) was added to the trimesic acid solution and stirred at 300 r / min for 60 min, and the resulting product was washed four times with deionized water / ethanol solution and dried at 60° C. for 24 h to obtain a cerium-metal organic framework material (Ce-MOF).

[0052] Step S3: At room temperature (20°C), with anhydrous ethanol (EtOH) as solvent, weigh 6.0g SS@PDA particles and 1.2g Ce-MOF particles and place them in a 500mL three-necked flask, add 300mL EtOH and react at 60°C at a speed of 200r / min for 24h. Then centrifuge and dry three times with anhydrous ethanol / deionized water, and dry in a blast drying oven at 60°C for 12h to obtain cerium-metal organic framework grafted polydopamine modified steel slag flame retardant particles.

[0053] Step S4: at 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer are added to the stirrer in sequence. 10 parts of cerium-metal organic framework grafted polydopamine modified steel slag, 20 parts of ammonium polyphosphate and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-3.

[0054] Comparative Example 1

[0055] At 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer were added to the stirrer in sequence. 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at 1000r / min for 10s until it is uniform and has a wire drawing phenomenon, then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for aging for 5h to obtain a pure rigid polyurethane foam insulation material, which is marked as pure rigid polyurethane foam.

[0056] Comparative Example 2

[0057] At 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer were added to the stirrer in sequence. 10 parts of cerium-metal organic framework material, 20 parts of ammonium polyphosphate, and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-1.

[0058] Comparative Example 3

[0059] At 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer were added to the stirrer in sequence. 10 parts of polydopamine modified steel slag, 20 parts of ammonium polyphosphate, and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-2.

[0060] Figure 1 The scanning electron microscope photos of the cerium-metal organic framework material, polydopamine modified steel slag, and cerium-metal organic framework material grafted polydopamine modified steel slag in Example 1, wherein a is the cerium-metal organic framework material, b is the polydopamine modified steel slag, and c is the cerium-metal organic framework material grafted polydopamine modified steel slag. It can be seen that the cerium-metal organic framework material is a rod-like structure, the surface of the polydopamine modified steel slag is relatively rough, and the surface of the cerium-metal organic framework material grafted polydopamine modified steel slag is relatively smooth. The above structure further enhances the synergistic flame retardant and smoke suppression and toxicity reduction effects of the cerium-metal organic framework material grafted polydopamine modified steel slag.

[0061] Figure 2 The heat release rate curves of pure rigid polyurethane foam, flame retardant rigid polyurethane foam-1, flame retardant rigid polyurethane foam-2, and flame retardant rigid polyurethane foam-3 obtained by cone calorimetry test are as high as 553.5kW / m 2 ; The peak heat release rate of flame retardant rigid polyurethane foam-1 decreased by 141kW / m 2 The peak heat release rate of flame retardant rigid polyurethane foam-2 was reduced by 147.9kW / m 2 The results showed that the compounding of ammonium polyphosphate with cerium-metal organic framework materials and polydopamine-modified steel slag reduced the heat release rate of the composite materials to a certain extent, effectively improving the fire safety of the composite materials; the peak heat release rate of flame-retardant rigid polyurethane foam-3 was reduced by 109.8kW / m 2, compared with pure rigid polyurethane foam, it decreased by 19.8%. The heat release of flame-retardant rigid polyurethane foam-3 gradually decreased after reaching the peak heat release rate, indicating that the flame retardant efficiency of cerium-metal organic framework material grafted with polydopamine modified steel slag can be improved through the flame retardant synergistic effect between shell steel slag and polydopamine, cerium-metal organic framework material and ammonium polyphosphate. Its flame retardant effect is also significantly better than that of flame-retardant rigid polyurethane foam-1 and flame-retardant rigid polyurethane foam-2 with the same amount of cerium-metal organic framework material and polydopamine modified steel slag.

[0062] Figure 3 The total smoke generation curves of pure rigid polyurethane foam, flame retardant rigid polyurethane foam-1, flame retardant rigid polyurethane foam-2, and flame retardant rigid polyurethane foam-3 obtained by cone calorimetry test over time. It can be seen that the final total smoke generation of pure rigid polyurethane foam is 976.7m 2 / m 2 After adding cerium-metal organic framework material, the final total smoke volume of flame-retardant rigid polyurethane foam-1 reached 1078.1m 2 / m 2 The results show that the addition of cerium-metal organic framework materials and ammonium polyphosphate promotes the generation of smoke particles during the combustion of rigid polyurethane foam. After adding equal amounts of polydopamine-modified steel slag and ammonium polyphosphate, the final total smoke generation of flame-retardant rigid polyurethane foam-2 is 996.2m 2 / m 2 Compared with the flame retardant rigid polyurethane foam-1, the final total smoke volume of the flame retardant rigid polyurethane foam-3 is 958.6m 2 / m 2 , which is 11.3% lower than that of flame-retardant rigid polyurethane foam-1, indicating that polydopamine-modified steel slag and cerium-metal organic framework grafted polydopamine-modified steel slag can effectively inhibit the generation of toxic smoke particles during the combustion of rigid polyurethane foam and improve its fire safety performance.

[0063] Example 2

[0064] The flame-retardant rigid polyurethane foam of the halogen-free flame retardant prepared in this embodiment and its preparation method are to prepare polydopamine-modified steel slag by bio-based polydopamine, prepare rare earth metal organic framework material by coordination chemistry strategy, and then prepare rare earth metal organic framework material grafted polydopamine-modified steel slag flame retardant by grafting action between polydopamine-modified steel slag and rare earth metal organic framework material, and finally, the rare earth metal organic framework material grafted polydopamine-modified steel slag flame retardant, halogen-free flame retardant and polyol, amine catalyst, organotin catalyst, chemical foaming agent, physical foaming agent, foam stabilizer and polyisocyanate are stirred at high speed until wire drawing occurs, and the flame-retardant rigid polyurethane foam insulation material is prepared by aging in an oven. Among them, aluminum hypophosphite is selected as the halogen-free flame retardant, and scandium nitrate is selected as the metal salt used to prepare the rare earth metal organic framework material. The rare earth metal organic framework grafted polydopamine-modified steel slag flame retardant is prepared according to the following steps and applied to the flame-retardant rigid polyurethane foam insulation material:

[0065] Step S1: At room temperature (20°C), weigh 0.5g dopamine hydrochloride and 10g steel slag into a 500mL three-necked flask, then add 250mL deionized water to dissolve the fixed drug, draw 2.5mL Tris-HCl buffer solution (10mmol / L) into the three-necked flask, adjust the pH to 8.5 with ammonia water, stir at 200r / min for 24h, and centrifuge three times with anhydrous ethanol and deionized water after the reaction. Then dry in a blast drying oven at 60°C to obtain polydopamine modified steel slag (SS@PDA).

[0066] Step S2: 40 mL of anhydrous ethanol and 40 mL of deionized water were transferred into a 500 mL three-necked flask, and 8.4 g of trimesic acid was added and stirred at 60° C. Subsequently, 180 mL of scandium nitrate (10 wt%) was added to the trimesic acid solution and stirred at 300 r / min for 1 h, and the resulting product was washed four times with deionized water / ethanol solution and dried at 60° C. for 24 h to obtain a scandium-metal organic framework material (Sc-MOF).

[0067] Step S3: At room temperature (20°C), with anhydrous ethanol (EtOH) as solvent, weigh 6.0g SS@PDA particles and 1.2g Sc-MOF particles and place them in a 500mL three-necked flask, add 300mL EtOH and react at 60°C at a speed of 200r / min for 24h. Then centrifuge and dry three times with anhydrous ethanol / deionized water, and dry in a blast drying oven at 60°C for 12h to obtain scandium-metal organic framework grafted polydopamine modified steel slag flame retardant particles.

[0068] Step S4: at 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer are added to the stirrer in sequence. 10 parts of scandium-metal organic framework material grafted polydopamine modified steel slag, 20 parts of aluminum hypophosphite and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-6.

[0069] Comparative Example 4

[0070] At 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer were added to the stirrer in sequence. 10 parts of scandium-metal organic framework material, 20 parts of aluminum hypophosphite, and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-4.

[0071] Comparative Example 5

[0072] At 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer were added to the stirrer in sequence. 10 parts of polydopamine modified steel slag, 20 parts of aluminum hypophosphite, and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-5.

[0073] Example 3

[0074] The flame-retardant rigid polyurethane foam of the halogen-free flame retardant prepared in this embodiment and its preparation method are to prepare polydopamine-modified steel slag by bio-based polydopamine, prepare rare earth metal organic framework material by metal organic framework, and then prepare rare earth metal organic framework material grafted polydopamine-modified steel slag flame retardant by grafting action between polydopamine-modified steel slag and rare earth metal organic framework material, and finally, the rare earth metal organic framework material grafted polydopamine-modified steel slag flame retardant, halogen-free flame retardant and polyol, amine catalyst, organotin catalyst, chemical foaming agent, physical foaming agent, foam stabilizer and polyisocyanate are stirred at high speed until wire drawing occurs, and the flame-retardant rigid polyurethane foam insulation material is prepared by aging in an oven. Among them, diethyl aluminum hypophosphite is selected as the halogen-free flame retardant, and neodymium nitrate is selected as the metal salt for preparing the rare earth metal organic framework material. The rare earth metal organic framework material grafted polydopamine-modified steel slag flame retardant is prepared according to the following steps and applied to the flame-retardant rigid polyurethane foam insulation material:

[0075] Step S1: At room temperature (20°C), weigh 0.5g dopamine hydrochloride and 10g steel slag into a 500mL three-necked flask, then add 250mL deionized water to dissolve the fixed drug, draw 2.5mL Tris-HCl buffer solution (10mmol / L) into the three-necked flask, adjust the pH to 8.5 with ammonia water, stir at 200r / min for 24h, and centrifuge three times with anhydrous ethanol and deionized water after the reaction. Then dry in a blast drying oven at 60°C to obtain polydopamine modified steel slag (SS@PDA).

[0076] Step S2: 40 mL of anhydrous ethanol and 40 mL of deionized water were transferred to a 500 mL three-necked flask, and 8.4 g of trimesic acid was added and stirred at 60° C. Subsequently, 180 mL of neodymium nitrate (10 wt%) was added to the trimesic acid solution and stirred at 300 r / min for 1 h, and the resulting product was washed four times with a deionized water / ethanol solution and dried at 60° C. for 24 h to obtain a neodymium-metal organic framework material (Nd-MOF).

[0077] Step S3: At room temperature (20°C), with anhydrous ethanol (EtOH) as solvent, weigh 6.0g SS@PDA particles and 1.2g Nd-MOF particles and place them in a 500mL three-necked flask, add 300mL EtOH and react at 60°C at a speed of 200r / min for 24h. Then centrifuge and dry three times with anhydrous ethanol / deionized water, and dry in a blast drying oven at 60°C for 12h to obtain neodymium-metal organic framework grafted polydopamine modified steel slag flame retardant particles.

[0078] Step S4: at 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer are added to the stirrer in sequence. 10 parts of neodymium-metal organic framework material grafted polydopamine modified steel slag, 20 parts of diethyl aluminum hypophosphite and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-9.

[0079] Comparative Example 6

[0080] At 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer were added to the stirrer in sequence. 10 parts of neodymium-metal organic framework material, 20 parts of diethyl aluminum hypophosphite, and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-7.

[0081] Comparative Example 7

[0082] At 30°C, 100 parts of polyester polyol with a hydroxyl value of 430 mgKOH / g, 1 part of amine catalyst Polycat 5, 0.5 parts of organic tin catalyst dibutyltin dilaurate, 2 parts of chemical foaming agent dimethyl carbonate, 30 parts of physical foaming agent 1,1,1,2-tetrafluoroethane (HFC-134A), and 1.5 parts of foam stabilizer were added to the stirrer in sequence. 10 parts of polydopamine modified steel slag, 20 parts of diethyl aluminum hypophosphite, and 138 parts of polyisocyanate with an NCO content of 30.5wt% are stirred at a high speed of 1000r / min for 10s until they are uniform and have a wire drawing phenomenon, and then injected into a mold for foaming. After the foam is formed, the foam is taken out and placed in an oven at 60°C for ripening for 5h to obtain a flame retardant rigid polyurethane foam insulation material, which is marked as flame retardant rigid polyurethane foam-8.

[0083] Table 1 shows the flame retardant properties, mechanical properties, thermal insulation properties and total CO production tests of pure rigid polyurethane foam, flame retardant rigid polyurethane foam-1, flame retardant rigid polyurethane foam-2, flame retardant rigid polyurethane foam-3, flame retardant rigid polyurethane foam-4, flame retardant rigid polyurethane foam-5, flame retardant rigid polyurethane foam-6, flame retardant rigid polyurethane foam-7, flame retardant rigid polyurethane foam-8, and flame retardant rigid polyurethane foam-9. It can be seen that after adding rare earth metal organic framework grafted polydopamine modified steel slag and ammonium polyphosphate, the compressive strength of flame retardant rigid polyurethane foam-3 is 0.361MPa, the thermal conductivity is only 0.0307W / m·k, its limiting oxygen index is as high as 24.9vol%, the vertical combustion level is UL-94V-0 level, and the total CO production is 2.025g. After adding rare earth metal organic framework material grafted polydopamine modified steel slag and aluminum hypophosphite, the compressive strength of flame retardant rigid polyurethane foam-6 is 0.351MPa, the thermal conductivity is only 0.0318W / m·k, its limiting oxygen index is as high as 24.6vol%, the vertical combustion level is UL-94V-0 level, and the total CO production is 2.106g. After adding rare earth metal organic framework material grafted polydopamine modified steel slag and aluminum diethylphosphinate, the compressive strength of flame retardant rigid polyurethane foam-9 is 0.367MPa, the thermal conductivity is only 0.0319W / m·k, its limiting oxygen index is as high as 25.0vol%, the vertical combustion level is UL-94V-0 level, and the total CO production is 2.024g. The data showed that the flame retardant properties, compressive strength, thermal insulation properties and total CO production of flame retardant rigid polyurethane foam-3, flame retardant rigid polyurethane foam-6 and flame retardant rigid polyurethane foam-9 were significantly better than those of pure rigid polyurethane foam and the flame retardant rigid polyurethane foam in the comparative example, indicating that rare earth metal organic framework material grafted polydopamine modified steel slag can significantly improve the flame retardant properties, compressive strength, thermal insulation properties of rigid polyurethane foam and reduce CO production.

[0084] Table 1 Test results of flame retardancy, mechanical properties, thermal insulation properties and total CO production of rigid polyurethane foam

[0085]

[0086]

Claims

1. A flame retardant rigid polyurethane foam thermal insulation material, characterized in that: The raw materials for preparing the thermal insulation material are composed of the following by mass: The amine catalyst is one or more of triethylamine, triethanolamine, pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, tris(dimethylaminopropyl)amine, and tris(dimethylaminopropyl)hexahydrotriazine; The organotin catalyst is one or more of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate; The foam stabilizer is a silicone oil surfactant; The rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant comprises: 5-10 parts of polydopamine modified steel slag; 1-2 parts of rare earth metal organic framework material; 300-500 parts of anhydrous ethanol; The polydopamine modified steel slag comprises: The rare earth metal organic framework material comprises: The chemical solvent is one or more of deionized water and anhydrous ethanol.

2. A flame retardant rigid polyurethane foam thermal insulation material as claimed in claim 1, characterized in that: The halogen-free flame retardant is one or more of ammonium polyphosphate, piperazine pyrophosphate, aluminum hypophosphite, diethyl aluminum hypophosphite, and melamine polyphosphate.

3. The flame retardant rigid polyurethane foam thermal insulation material according to claim 1, characterized in that: The polyol is one or more of polyester polyol having a hydroxyl value of 300-500 mgKOH / g or polyether polyol having a hydroxyl value of 380-500 mgKOH / g.

4. The flame retardant rigid polyurethane foam thermal insulation material according to claim 1, characterized in that: The polyisocyanate is polymethylene polyphenyl polyisocyanate with an NCO group mass percentage of 29.5-32.5 wt %.

5. The flame retardant rigid polyurethane foam thermal insulation material according to claim 1, characterized in that: The chemical foaming agent is one or more of pure water, dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate.

6. The flame retardant rigid polyurethane foam thermal insulation material according to claim 1, characterized in that: The physical foaming agent is one or more of cyclopentane, n-pentane, isopentane, butane, 1,1,1,2-tetrafluoroethane, pentafluoropropane, pentafluorobutane, heptafluoropropane, monofluorodichloroethane, trans-1-chloro-3,3,3-trifluoropropene, and 1,1,1,4,4,4-hexafluoro-2-butene.

7. The flame retardant rigid polyurethane foam thermal insulation material according to claim 1, characterized in that: The rare earth metal organic framework material is one or more of a cerium-metal organic framework material, a scandium-metal organic framework material, a neodymium-metal organic framework material, a gadolinium-metal organic framework material, and a yttrium-metal organic framework material.

8. The flame retardant rigid polyurethane foam thermal insulation material according to claim 1, characterized in that: The rare earth metal salt solution is one or more of cerium nitrate, scandium nitrate, neodymium nitrate, gadolinium nitrate and yttrium nitrate.

9. The method for preparing a flame retardant rigid polyurethane foam thermal insulation material according to claim 1, characterized in that The steps include: Step S1 is the preparation of polydopamine modified steel slag: at room temperature, dopamine hydrochloride and steel slag are added to a reactor equipped with a stirrer, and dispersed in a chemical solvent, and then 1-30mmol / L tris(hydroxymethyl)aminomethane-hydrochloride buffer solution is added, and the solution pH is adjusted to 6-10 with ammonia water, and then stirred at a speed of 100-500r / min for 24h. After the reaction is completed, the obtained mixed solution is centrifuged and dried to obtain polydopamine modified steel slag; Step S2 is the preparation of a rare earth metal organic framework material: under room temperature, a chemical solvent is added to a reactor equipped with a stirrer, and trimesic acid is added and stirred evenly at a temperature of 40-80° C.; then, a 5.0-40.0wt% rare earth metal salt solution is added to the trimesic acid solution and stirred at a speed of 100-500 r / min, and the obtained product is washed and dried to obtain a rare earth metal organic framework material; Step S3 is the preparation of a rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant: at room temperature, add polydopamine modified steel slag and rare earth metal organic framework material to a reactor equipped with a stirrer, disperse them in anhydrous ethanol, and stir at a high speed of 100-500r / min at a temperature of 40-80°C for 6-36h; then centrifuge, wash, and dry to obtain a rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant; Step S4 is the preparation of flame-retardant rigid polyurethane foam insulation material: under the condition of 25-30°C, polyol, amine catalyst, organic tin catalyst, chemical foaming agent, physical foaming agent, foam stabilizer, rare earth metal organic framework material grafted polydopamine modified steel slag flame retardant, halogen-free flame retardant and polyisocyanate are added to the stirring device in sequence, and after high-speed stirring until uniform and wire drawing occurs, the mixture is injected into the mold for foaming. After the foam is formed, the foam is taken out and placed in an oven for maturation to obtain a flame-retardant rigid polyurethane foam insulation material.

10. The method for preparing a flame retardant rigid polyurethane foam thermal insulation material according to claim 9, characterized in that: In step S4, the stirring speed is 200-3500 r / min; the stirring time is 3-40 s; the aging temperature is 40-90° C.; and the aging time is 0.5-24 h.

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