Modified polymer cement-based normal-temperature foaming fireproof coating and preparation method thereof

Abstract

The invention discloses a modified polymer cement-based normal-temperature foaming fireproof coating and a preparation method thereof, and relates to the technical field of fireproof coatings. The modified polymer cement-based normal-temperature foaming fireproof coating comprises a component A and a component B, the component A is prepared from the following raw materials in parts by weight: 15 to 20 parts of cement, 10 to 12 parts of calcium carbonate, 0.3 to 0.9 part of nano titanium dioxide, 30 to 35 parts of polyurethane emulsion, 1 to 2 parts of cross-linking agent, 8 to 12 parts of flame retardant, 1 to 3 parts of foaming agent, 0.5 to 1.5 parts of dispersing agent and 10 to 20 parts of deionized water; the component B comprises the following raw materials in parts by weight: 20-25 parts of a curing agent, 0.1-0.5 part of an organic zinc catalyst and 0.5-1.2 parts of a foam stabilizer; the prepared modified polymer cement-based normal-temperature foaming fireproof coating has excellent fireproof performance, bonding strength and compressive strength.

Description

Technical Field

[0001] This invention relates to the field of fire-retardant coating technology, specifically to a modified polymer cement-based room-temperature foaming fire-retardant coating and its preparation method. Background Technology

[0002] With the widespread application of steel structure buildings, the problem of significant attenuation of load-bearing capacity and stiffness due to rapid temperature rise under fire conditions has become increasingly prominent. The flame-retardant and heat-insulating properties of fire-retardant coatings have become one of the key technologies for ensuring the fire safety of steel structures. Cement-based fire-retardant coatings have promising applications in the field of building fire protection due to their wide availability of raw materials, low cost, good durability, and environmental friendliness. However, traditional cement-based fire-retardant coatings generally suffer from defects such as high brittleness, susceptibility to drying shrinkage and thermal cracking, and high self-weight, making it difficult to meet the demands for high-performance, lightweight fire protection. To improve their mechanical properties, organic components are often introduced into the cement-based system. However, the interfacial compatibility between organic matter and inorganic cement matrix is ​​insufficient, easily leading to phase separation or interfacial weakening, resulting in performance degradation. Simultaneously, the foaming structure introduced to achieve lightweight and heat-insulating effects may compromise the material's density, thereby weakening its overall flame-retardant performance and limiting the comprehensive performance improvement of cement-based fire-retardant coatings.

[0003] Chinese invention patent CN113913042A discloses a magnesium silicate cement-based thin-film fireproof coating for steel structures and its application method. It uses a magnesium silicate-based cementitious material prepared from magnesite tailings as the base material. The coating is prepared by mixing and stirring lightly calcined magnesium oxide, silica fume, waterproofing agent, lightweight fine aggregate, reinforcing material, flame retardant, foaming agent, foam stabilizer, and water. When the magnesium silicate material is exposed to a flame heat source, the flame heat source first slowly releases the water in the crystalline phase as water vapor, effectively delaying the transfer of heat from the flame. Magnesium oxide is a high-temperature resistant metallic compound, resulting in good thermal insulation of the magnesium silicate cement-based thin-film fireproof coating for steel structures. After foaming, it prevents heat conduction and has good fireproof performance, but its mechanical properties are still insufficient.

[0004] Therefore, developing a cement-based foamed fireproof coating system that combines excellent flame retardant and heat insulation properties with good mechanical properties has important application value in the current field of building fire protection. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a modified polymer cement-based room-temperature foaming fireproof coating and its preparation method.

[0006] A modified polymer cement-based room-temperature foaming fireproof coating, comprising component A and component B; Component A comprises the following raw materials in parts by weight: 15-20 parts cement, 10-12 parts calcium carbonate, 0.3-0.9 parts nano titanium dioxide, 30-35 parts polyurethane emulsion, 1-2 parts crosslinking agent, 8-12 parts flame retardant, 1-3 parts foaming agent, 0.5-1.5 parts dispersant, and 10-20 parts deionized water; Component B comprises the following raw materials in parts by weight: 20-25 parts curing agent, 0.1-0.5 parts organic zinc catalyst, and 0.5-1.2 parts foam stabilizer; The crosslinking agent has the following structural formula: ; The flame retardant has the following structural formula: .

[0007] The crosslinking agent is prepared by the following method: S1: Oleic acid reacts with N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether to form a four-armed compound; the reaction is illustrated below:

[0008] S2: The four-armed compound reacts with L-cysteine ​​to yield a crosslinking agent. The reaction is illustrated below:

[0009] In step S1, the molar ratio of oleic acid and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether is (4.08-4.1):1.

[0010] In step S2, the molar ratio of the four-armed compound to L-cysteine ​​is 1:(4.05-4.08).

[0011] The flame retardant is prepared by the following method: N1: The reaction of phenyltris(dimethylsiloxane)silane with 5-hexen-1-amine yields intermediate 1, as illustrated below:

[0012] N2: Intermediate 1 reacts with 3-methoxy-4-hydroxybenzaldehyde to give intermediate 2, as shown in the following diagram:

[0013] N3: Intermediate 2 reacts with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to yield the flame retardant. The reaction is illustrated below:

[0014] In step N1, the molar ratio of phenyltris(dimethylsiloxane)silane to 5-hexen-1-amine is 1:3.05.

[0015] In step N2, the molar ratio of intermediate 1 to 3-methoxy-4-hydroxybenzaldehyde is 1:3.08.

[0016] In step N3, the molar ratio of intermediate 2 to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:3.08.

[0017] The foaming agent is hydrogen peroxide; the foam stabilizer is polyvinyl alcohol; the dispersant is a mixture of sodium hexametaphosphate and sodium polycarboxylate; the curing agent is waterborne polyurethane curing agent Bayhydur XP 2655; and the organic zinc catalyst is zinc 2-ethylhexanoate.

[0018] A method for preparing a modified polymer cement-based room-temperature foaming fire-retardant coating includes the following steps: (1) Weigh out the following by weight: 15-20 parts cement, 10-12 parts calcium carbonate, 0.3-0.9 parts nano titanium dioxide, 30-35 parts polyurethane emulsion, 1-2 parts crosslinking agent, 8-12 parts flame retardant, 1-3 parts foaming agent, 0.5-1.5 parts dispersant, 10-20 parts deionized water, 20-25 parts curing agent, 0.1-0.5 parts organic zinc catalyst, and 0.5-1.2 parts foam stabilizer; (2) Stir and mix deionized water and dispersant, then add cement, calcium carbonate and nano titanium dioxide in sequence, heat and stir until mixed, then add polyurethane emulsion, crosslinking agent, flame retardant and foaming agent and mix evenly to obtain component A; stir and mix curing agent, organic zinc catalyst and foam stabilizer to obtain component B; add component B to component A and stir until mixed to obtain modified polymer cement-based room temperature foaming fireproof coating.

[0019] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include: The modified polymer cement-based room-temperature foamed fireproof coating prepared by this invention has excellent fireproof performance, bonding strength, and compressive strength. Attached Figure Description

[0020] Figure 1 The image shows the 1H NMR spectrum of the crosslinking agent prepared in Example 1.

[0021] Figure 2 The image shows a high-resolution mass spectrum of the crosslinking agent prepared in Example 1.

[0022] Figure 3 The image shows the proton NMR spectrum of the flame retardant prepared in Example 4.

[0023] Figure 4The image shows a high-resolution mass spectrum of the flame retardant prepared in Example 4. Detailed Implementation

[0024] Example 1 Preparation of crosslinking agent S1: 800 ml toluene, 0.408 mol oleic acid, 0.1 mol N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, and 0.02 mol tetraethylammonium bromide were sequentially added to a reaction flask, stirred and mixed, heated to 100 °C, and reacted for 6 h. After cooling to room temperature, the mixture was washed sequentially with 200 ml saturated sodium bicarbonate and 2 × 200 ml saturated brine, dried over 60 g anhydrous magnesium sulfate, filtered, and rotary evaporated at 70 °C to constant weight to obtain the four-armed compound; its 1H NMR spectrum data are as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 6.82 (s, 8H), 5.33 (t, J = 5.5 Hz, 8H), 4.25 – 4.11 (m, 8H), 4.10 – 3.96 (m, 8H), 3.52 (dd, J = 12.4, 5.8 Hz, 4H), 3.38 (dd, J = 12.4, 5.9Hz, 4H), 2.32 (t, J = 8.5 Hz, 8H), 2.06 – 1.96 (m, 16H), 1.66 – 1.55 (m, 8H), 1.38 – 1.22 (m, 80H), 0.95 – 0.83 (m, 12H); HRMS (m / z): 1555.2273[M+H] + ; S2: Under nitrogen protection, 800 ml of DMF, 0.1 mol of the four-arm compound, 0.405 mol of L-cysteine, and 4 g of photoinitiator 184 were added sequentially to the reaction flask, stirred and mixed thoroughly, and the mixture was incubated at room temperature with an intensity of 20 mW / cm². 2 The reaction was carried out under 365nm ultraviolet LED light for 2 hours, followed by rotary evaporation at 80℃ to constant weight. 700ml of diethyl ether was added and stirred to precipitate the mixture. The precipitate was filtered, and the filter cake was washed with a mixed solution of diethyl ether and anhydrous ethanol (volume ratio of diethyl ether to anhydrous ethanol 1:2) (3 × 50ml). The mixture was then vacuum dried at 50℃ for 12 hours to obtain the crosslinking agent. Its 1H NMR spectrum is shown below. Figure 2 As shown, the proton NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d) δ11.39 (s, 4H), 6.83 (s, 8H), 4.24 – 4.10 (m, 8H), 4.09 – 3.94 (m, 8H), 3.64 –3.57 (m, 12H), 3.51 (dd, J = 12.2, 5.8 Hz, 4H), 3.39 (dd, J = 12.3, 5.8 Hz, 4H), 3.03 – 2.85 (m, 8H), 2.75 (p, J = 5.6 Hz, 4H), 2.34 (t, J = 8.4 Hz, 8H), 1.65 – 1.43 (m, 24H), 1.40 – 1.23 (m, 88H), 0.97 – 0.84 (m, 12H); its high-resolution mass spectrum is as follows Figure 2 As shown, HRMS (m / z): 2039.3061 [M+H] + .

[0025] Example 2 Preparation of crosslinking agent S1: 800 ml toluene, 0.409 mol oleic acid, 0.1 mol N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether and 0.02 mol tetraethylammonium bromide were added sequentially to a reaction flask, stirred and mixed, heated to 105 °C, reacted for 5 h, cooled to room temperature, washed sequentially with 200 ml saturated sodium bicarbonate and 2 × 200 ml saturated brine, dried with 60 g anhydrous magnesium sulfate, filtered, and rotary evaporated at 70 °C to constant weight to obtain the four-armed compound; S2: Under nitrogen protection, 800 ml of DMF, 0.1 mol of the four-arm compound, 0.406 mol of L-cysteine, and 4 g of photoinitiator 184 were added sequentially to the reaction flask, stirred and mixed thoroughly, and incubated at room temperature at 20 mW / cm². 2 The reaction was carried out under ultraviolet light for 3 hours, and then rotary evaporated at 80°C to constant weight. 700 ml of diethyl ether was added and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with a mixed solution of diethyl ether and anhydrous ethanol (volume ratio of diethyl ether to anhydrous ethanol is 1:2) (3 × 50 ml). The mixture was then vacuum dried at 50°C for 12 hours to obtain the crosslinking agent.

[0026] Example 3 Preparation of crosslinking agent S1: 800 ml toluene, 0.41 mol oleic acid, 0.1 mol N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether and 0.02 mol tetraethylammonium bromide were added sequentially to a reaction flask, stirred and mixed, heated to 110 °C, reacted for 4 h, cooled to room temperature, washed sequentially with 200 ml saturated sodium bicarbonate and 2 × 200 ml saturated brine, dried with 60 g anhydrous magnesium sulfate, filtered, and rotary evaporated at 70 °C to constant weight to obtain the four-armed compound; S2: Under nitrogen protection, 800 ml of DMF, 0.1 mol of the four-arm compound, 0.408 mol of L-cysteine, and 4 g of photoinitiator 184 were added sequentially to the reaction flask, stirred and mixed thoroughly, and incubated at room temperature at 20 mW / cm². 2 The reaction was carried out under ultraviolet light for 4 hours, and then rotary evaporated at 80°C to constant weight. 700 ml of diethyl ether was added and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with a mixed solution of diethyl ether and anhydrous ethanol (volume ratio of diethyl ether to anhydrous ethanol is 1:2) (3 × 50 ml). The mixture was then vacuum dried at 50°C for 12 hours to obtain the crosslinking agent.

[0027] Example 4 Preparation of flame retardant N1: Under nitrogen protection, 300 ml of anhydrous toluene, 100 mg of Karstedt catalyst, and 0.305 mol of 5-hexen-1-amine were added sequentially to a reaction flask, stirred and mixed, and heated to 70 °C. Then, 200 ml of anhydrous toluene solution containing 0.1 mol of phenyltris(dimethylsiloxane)silane was slowly added dropwise over 30 min. After the addition was complete, the reaction was allowed to proceed for 6 h. The mixture was cooled to room temperature and rotary evaporated at 70 °C to constant weight. Then, 200 ml of diethyl ether was added and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with a mixed solution of diethyl ether and anhydrous ethanol (volume ratio of diethyl ether to anhydrous ethanol 1:1) (2 × 50 ml). The mixture was then dried under vacuum at 60 °C for 10 h to obtain intermediate 1. Its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 7.62 – 7.51 (m, 2H), 7.40 – 7.30 (m, 3H), 2.75 – 2.56 (m, 6H), 1.88 (d, J = 13.0 Hz, 6H), 1.55 – 1.39 (m, 12H), 1.31(dq, J = 8.0, 6.5 Hz, 6H), 1.25 – 1.13 (m, 6H), 0.80 (t, J = 8.4 Hz, 6H), 0.10 (s, 18H); HRMS (m / z): 628.4109[M+H] + ; Under nitrogen protection, 600 ml of anhydrous ethanol, 0.308 mol of 3-methoxy-4-hydroxybenzaldehyde, 0.1 mol of intermediate 1, and 20 g of 4A molecular sieve were sequentially added to a reaction flask. The mixture was stirred and stirred until homogeneous, then heated to reflux and reacted for 7 h. After cooling to room temperature, the mixture was filtered, and the filtrate was rotary evaporated at 50 °C to constant weight. It was recrystallized using 350 ml of 50 wt% ethanol, filtered, and dried under vacuum at 60 °C for 10 h to obtain intermediate 2. Its 1H NMR data are as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 9.24 (s, 3H), 8.30 (s, 3H), 7.58 – 7.50 (m, 2H), 7.41 – 7.32 (m, 3H), 7.23 (d, J = 1.8 Hz, 3H), 7.15 (dd,J = 8.7, 1.9 Hz, 3H), 6.83 (d, J = 8.7 Hz, 3H), 3.82 (s, 9H), 3.29 (d, J =13.8 Hz, 6H), 1.68 (p, J = 7.3 Hz, 6H), 1.52 – 1.32 (m, 12H), 1.31 – 1.18 (m,6H), 0.81 (t, J = 8.3 Hz, 6H), 0.11 (s, 18H); HRMS (m / z): 1030.5212[M+H] + ; Under nitrogen protection, 800 ml of DMF, 0.1 mol of intermediate 2, and 0.308 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide were sequentially added to a reaction flask, stirred and mixed, heated to 120 °C, and reacted for 6 h. After cooling to room temperature, the mixture was rotary evaporated at 80 °C to constant weight. 500 ml of deionized water was added, and the mixture was stirred to precipitate. The precipitate was filtered, and the filter cake was washed with 50 wt% methanol aqueous solution (2 × 50 ml). The cake was then vacuum dried at 60 °C for 12 h to obtain the flame retardant. Its proton NMR spectrum is shown below. Figure 3 As shown, the proton NMR data are as follows: 1 HNMR (400 MHz, DMSO- d6) δ 8.52 (s, 3H), 8.23 ​​(dd, J = 7.3, 1.5 Hz, 3H), 8.07 (dd, J = 7.3, 1.3 Hz, 3H), 8.00 (dd, J = 7.7, 1.3 Hz, 3H), 7.71 (td, J = 7.2,1.3 Hz, 3H), 7.61 – 7.52 (m, 8H), 7.51 – 7.45 (m, 3H), 7.40 – 7.29 (m, 6H),7.02 – 6.95 (m, 6H), 6.82 (d, J = 8.5 Hz, 3H), 5.11 (dt, J = 8.4, 1.1 Hz,3H), 4.19 (dt, J = 8.2, 5.5 Hz, 3H), 3.81 (s, 9H), 2.82 – 2.65 (m, 6H), 1.59– 1.38 (m, 12H), 1.37 – 1.18 (m, 12H), 0.87 – 0.75 (m, 6H), 0.12 (s, 18H); its high-resolution mass spectrum is as follows: Figure 4 As shown, HRMS (m / z): 1678.6231 [M+H] + .

[0028] Example 5: Preparation of Modified Polymer Cement-Based Room Temperature Foaming Fire-Retardant Coating (1) Weigh out: 150g cement, 100g calcium carbonate, 3g nano titanium dioxide, 300g polyurethane emulsion, 10g crosslinking agent (prepared in Example 1), 80g flame retardant (prepared in Example 4), 10g foaming agent (30wt% H2O2), 5g dispersant (2g sodium hexametaphosphate, 3g sodium polycarboxylate), 100g deionized water, 200g curing agent (Bayhydur XP 2655), 1g organic zinc catalyst (zinc 2-ethylhexanoate), and 5g foam stabilizer (polyvinyl alcohol); (2) Deionized water and dispersant were added to a high-speed disperser in sequence and stirred at 300 rpm for 10 min. Cement, calcium carbonate and nano titanium dioxide were added in sequence and heated to 30°C. The mixture was dispersed at 1500 rpm for 60 min and cooled to room temperature. Polyurethane emulsion, crosslinking agent, flame retardant and foaming agent were added in sequence and stirred at 300 rpm for 20 min to obtain component A. Curing agent, organic zinc catalyst and foam stabilizer were added to a mixer in sequence and stirred at 600 rpm for 20 min to obtain component B. Component A and component B were stirred at 300 rpm for 30 min to obtain modified polymer cement-based room temperature foaming fireproof coating.

[0029] Example 6 Preparation of Modified Polymer Cement-Based Room Temperature Foaming Fireproof Coating (1) Weigh out: 180g cement, 110g calcium carbonate, 8g nano titanium dioxide, 320g polyurethane emulsion, 15g crosslinking agent (prepared in Example 2), 100g flame retardant (prepared in Example 4), 20g foaming agent (30wt% H2O2), 10g dispersant (4g sodium hexametaphosphate, 6g sodium polycarboxylate), 150g deionized water, 230g curing agent (Bayhydur XP 2655), 4g organic zinc catalyst (zinc 2-ethylhexanoate), and 10g foam stabilizer (polyvinyl alcohol); (2) Deionized water and dispersant were added to a high-speed disperser in sequence and stirred at 400 rpm for 10 min. Cement, calcium carbonate and nano titanium dioxide were added in sequence and heated to 35°C. The mixture was dispersed at 1800 rpm for 40 min and cooled to room temperature. Polyurethane emulsion, crosslinking agent, flame retardant and foaming agent were added in sequence and stirred at 300 rpm for 20 min to obtain component A. Curing agent, organic zinc catalyst and foam stabilizer were added to a mixer in sequence and stirred at 700 rpm for 20 min to obtain component B. Component A and component B were stirred at 300 rpm for 30 min to obtain modified polymer cement-based room temperature foaming fireproof coating.

[0030] Example 7 Preparation of Modified Polymer Cement-Based Room Temperature Foaming Fire-Retardant Coating (1) Weigh out: 200g cement, 120g calcium carbonate, 9g nano titanium dioxide, 350g polyurethane emulsion, 20g crosslinking agent (prepared in Example 3), 120g flame retardant (prepared in Example 4), 30g foaming agent (30wt% H2O2), 15g dispersant (5g sodium hexametaphosphate, 10g sodium polycarboxylate), 200g deionized water, 250g curing agent (Bayhydur XP 2655), 5g organic zinc catalyst (zinc 2-ethylhexanoate), and 12g foam stabilizer (polyvinyl alcohol); (2) Add deionized water and dispersant to a high-speed disperser in sequence, stir at 500 rpm for 10 min, add cement, calcium carbonate and nano titanium dioxide in sequence, heat to 40℃, disperse at 2000 rpm for 60 min, cool to room temperature, add polyurethane emulsion, crosslinking agent, flame retardant and foaming agent in sequence, stir at 300 rpm for 20 min to obtain component A; add curing agent, organic zinc catalyst and foam stabilizer in sequence to a mixer, stir at 800 rpm for 20 min to obtain component B; stir component A and component B at 300 rpm for 30 min to obtain modified polymer cement-based room temperature foaming fireproof coating.

[0031] Comparative Example 1 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fireproof coating are basically the same as those in Example 6, except that the crosslinking agent is replaced with an equal weight of crosslinking agent prepared by the following method: The preparation method of the crosslinking agent is basically the same as that in Example 2, except that N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether in step S1 is replaced with 0.2 mol of bis[4-(glycidyl oxy)phenyl]methane, and L-cysteine ​​in step S2 is replaced with 0.204 mol.

[0032] Comparative Example 2 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fireproof coating are basically the same as those in Example 6, except that the crosslinking agent is replaced with an equal weight of crosslinking agent prepared by the following method: The preparation method of the crosslinking agent is basically the same as that in Example 2, except that N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether in step S2 is replaced with an equimolar amount of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane.

[0033] Comparative Example 3 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fireproof coating are basically the same as those in Example 6, except that the crosslinking agent is replaced with an equal weight of crosslinking agent prepared by the following method: The preparation method of the crosslinking agent is basically the same as that in Example 2, except that the oleic acid in step S1 is replaced with an equimolar amount of 9-decenoic acid.

[0034] Comparative Example 4 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fireproof coating are basically the same as those in Example 6, except that the crosslinking agent is replaced with an equal weight of crosslinking agent prepared by the following method: The preparation method of the crosslinking agent is basically the same as that in Example 2, except that L-cysteine ​​in step S2 is replaced with 0.202 mol.

[0035] Comparative Example 5 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fire-retardant coating are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method: The preparation method of the flame retardant is basically the same as that in Example 4, except that 5-hexene-1-amine in step N1 is replaced with an equimolar amount of 1-amino-10-undecene.

[0036] Comparative Example 6 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fire-retardant coating are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method: The preparation method of the flame retardant is basically the same as that in Example 4, except that the phenyltris(dimethylsiloxane)silane in step N1 is replaced with an equimolar amount of methyltris(dimethylsiloxane)silane.

[0037] Comparative Example 7 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fire-retardant coating are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method: The preparation method of the flame retardant is basically the same as that in Example 4, except that the phenyltris(dimethylsiloxane)silane in step N1 is replaced with 0.075 mol of tetra(dimethylsiloxane)silane, the 3-methoxy-4-hydroxybenzaldehyde in step N2 is replaced with 0.41 mol, and the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in step N3 is replaced with 0.41 mol.

[0038] Comparative Example 8 The raw material composition and preparation method of the modified polymer cement-based room-temperature foaming fire-retardant coating are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method: The preparation method of the flame retardant is basically the same as that in Example 4, except that the phenyltris(dimethylsiloxane)silane in step N1 is replaced with 0.15 mol of 3-phenyl-1,1,3,5,5-pentamethyltrisiloxane, the 3-methoxy-4-hydroxybenzaldehyde in step N2 is replaced with 0.205 mol, and the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in step N3 is replaced with 0.205 mol.

[0039] The cement used in this application is ordinary Portland cement, model P·O 42.5 cement; the polyurethane emulsion is model HA-2750H, with a solid content of 35wt%, produced by Shanghai Hecheng Polymer Technology Co., Ltd.; the nano titanium dioxide is model YC-YTJ60, produced by Shanghai Yingcheng New Materials Co., Ltd.; the polyvinyl alcohol is model 17-80; and the sodium polycarboxylate is model SN-5040.

[0040] The modified polymer cement-based room temperature foamed fireproof coatings prepared in the examples and comparative examples were tested for fire resistance, bond strength and compressive strength according to GB 14907-2002 standard. The test results are shown in Table 1.

[0041] Preparation of test specimens for fire resistance performance: Take an I16 hot-rolled ordinary I-beam (500mm in length), and polish each surface with 80-grit sandpaper until smooth. Apply the modified polymer cement-based room temperature foamed fire retardant coating prepared in the examples and comparative examples evenly to each surface of the steel beam with a scraper. The coating thickness is 20mm. Cure for 7 days at an ambient temperature of 23℃ and a relative humidity of 50% to obtain the test specimens.

[0042] Preparation of test specimens for bonding strength: Q235 steel was used as the substrate (70mm×70mm×10mm in size). The surface was sanded smooth with 80-grit sandpaper. The modified polymer cement-based room temperature foaming fireproof coating prepared in the examples and comparative examples was evenly applied to the substrate surface with a scraper. The coating thickness was 8mm. The specimens were cured for 7 days at an ambient temperature of 23℃ and a relative humidity of 50% to obtain the test specimens.

[0043] Preparation of compressive strength test specimens: A thin layer of machine oil was applied to the inner wall of a metal mold with dimensions of 70.7mm×70.7mm×70.7mm. The modified polymer cement-based room temperature foaming fireproof coating prepared in the examples and comparative examples was injected into the mold. The mold was gently shaken, tamped, and smoothed. The mold was cured for 7 days at an ambient temperature of 23℃ and a relative humidity of 50%. The mold was then removed and dried in an oven at 60℃ for 48 hours. After cooling to room temperature, the test specimens were obtained.

[0044] Table 1 Performance Test Data

[0045] As can be seen from the data in Table 1, the modified polymer cement-based room temperature foamed fireproof coating prepared by the present invention has excellent fireproof performance, bonding strength, and compressive strength.

[0046] The modified polymer cement-based room-temperature foaming fireproof coating prepared in this invention uses diphenyl methyl ether as the core crosslinking agent, which is linked to amino, carboxyl, and terminal alkyl chains via flexible alkyl chains. Specifically, the amino groups in the crosslinking agent and the hydroxyl groups in the polyurethane react with the isocyanate structure in the curing agent to form an interpenetrating crosslinked network in the coating, enhancing the overall strength and cohesiveness of the coating; the carboxyl groups in the crosslinked network react with the Ca in the cement matrix... 2+ Mg 2+The formation of coordination effects improves the interfacial bonding performance between inorganic cement and polyurethane, thereby enhancing the mechanical properties of the material. The rigid aromatic structure of diphenyl methyl ether acts as a stabilizing skeleton node in the crosslinking network, enhancing the stability of the fire-retardant coating and improving the overall compressive strength of the coating. The flexible alkyl segments can form an effective stress buffer in the crosslinking network, dispersing external loads, alleviating interfacial stress concentration, and inhibiting the generation and propagation of microcracks, thus reducing the brittleness of the material. The terminal alkyl chains further regulate hydrophobicity and compatibility, reducing microphase separation defects, thereby improving the mechanical properties of the material.

[0047] In Comparative Example 2, the core bridging agent was changed from ether oxygen to methylene, which was more rigid but less flexible than the crosslinking agent used in the example. This resulted in excessively high rigidity of the crosslinking network, which easily caused stress concentration and microcrack propagation, increased material brittleness, and decreased compressive strength.

[0048] The modified polymer cement-based room-temperature foaming fireproof coating prepared in this invention contains a flame retardant with phenyltris(dimethylsiloxane)silane as its core, linked by a flexible alkyl chain containing secondary amines, phosphate esters, and hydroxyl groups. The hydroxyl groups in the flame retardant can react with Ca in the cement hydration products. 2+ Mg 2+ The formation of complexes improves the dispersion of flame retardants in the matrix and constructs a stable interfacial transition layer between the organic polymer phase and the inorganic cement phase. Secondary amines can react with isocyanates in the curing agent, embedding themselves in the cross-linking network to further improve the mechanical properties of the coating and reduce the migration of flame retardant molecules, thus improving the long-term stability of flame retardancy. Phosphate groups can catalyze the formation of a dense carbonized layer on the surface of the polymer and cement matrix when heated. This carbonized layer has good heat insulation and oxygen barrier effects, inhibiting heat transfer to the interior and blocking the escape of combustible gases. At the same time, the siloxane structure introduced into the molecule is easily transformed into a stable Si-O-Si inorganic phase at high temperatures, which synergistically forms a high-temperature resistant ceramicized protective layer with the silicate structure in the cement matrix, improving the residual structural strength. Benzene rings easily form a dense carbon layer at high temperatures, further improving the flame retardant performance. The synergistic effect of phosphorus and silicon enables the flame retardant to simultaneously possess the dual functions of condensed phase flame retardancy and structural stability, significantly improving the fire resistance limit of the coating.

[0049] In Comparative Example 5, the flexible alkyl chain in the flame retardant was too long, and the spatial distance between the phenyltris(dimethylsiloxane)silane and the phosphate ester structure was too large. This hindered the formation of a compact and effective multifunctional synergistic structure, making it difficult for the phosphorus-silicon-aromatic structure to work synergistically during combustion, thus affecting the fire-retardant performance of the coating. In Comparative Example 7, the flame retardant had a four-arm structure, and the excessive secondary amine and polyurethane matrix caused excessive cross-linking, resulting in brittle fracture of the coating.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A modified polymer cement-based room-temperature foaming fireproof coating, characterized in that, Includes component A and component B; Component A comprises the following raw materials in parts by weight: 15-20 parts cement, 10-12 parts calcium carbonate, 30-35 parts polyurethane emulsion, 1-2 parts crosslinking agent, 8-12 parts flame retardant, 1-3 parts foaming agent, 0.5-1.5 parts dispersant, 0.3-0.9 parts nano titanium dioxide, and 10-20 parts deionized water; Component B comprises the following raw materials in parts by weight: 20-25 parts curing agent, 0.1-0.5 parts organic zinc catalyst, and 0.5-1.2 parts foam stabilizer; The crosslinking agent has the following structural formula: ； The flame retardant has the following structural formula: 。 2. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 1, characterized in that, The crosslinking agent is prepared by the following method: S1: Oleic acid reacts with N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether to form a four-armed compound; S2: The four-armed compound reacts with L-cysteine ​​to obtain a crosslinking agent.

3. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 2, characterized in that, In step S1, the molar ratio of oleic acid and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether is (4.08-4.1):

1.

4. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 2, characterized in that, In step S2, the molar ratio of the four-armed compound to L-cysteine ​​is 1:(4.05-4.08).

5. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 1, characterized in that, The flame retardant is prepared by the following method: N1: The reaction of phenyltris(dimethylsiloxane)silane with 5-hexen-1-amine yields intermediate 1. N2: Intermediate 1 reacts with 3-methoxy-4-hydroxybenzaldehyde to give intermediate 2. N3: Intermediate 2 reacts with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a flame retardant.

6. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 5, characterized in that, In step N1, the molar ratio of phenyltris(dimethylsiloxane)silane to 5-hexen-1-amine is 1:3.

05.

7. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 5, characterized in that, In step N2, the molar ratio of intermediate 1 to 3-methoxy-4-hydroxybenzaldehyde is 1:3.

08.

8. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 5, characterized in that, In step N3, the molar ratio of intermediate 2 to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:3.

08.

9. The modified polymer cement-based room-temperature foaming fireproof coating according to claim 1, characterized in that, The foaming agent is hydrogen peroxide; the foam stabilizer is polyvinyl alcohol; the dispersant is a mixture of sodium hexametaphosphate and sodium polycarboxylate; the curing agent is waterborne polyurethane curing agent Bayhydur XP 2655; and the organic zinc catalyst is zinc 2-ethylhexanoate.

10. A method for preparing a modified polymer cement-based room-temperature foaming fire-retardant coating according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Weigh out the following by weight: 15-20 parts cement, 10-12 parts calcium carbonate, 0.3-0.9 parts nano titanium dioxide, 30-35 parts polyurethane emulsion, 1-2 parts crosslinking agent, 8-12 parts flame retardant, 1-3 parts foaming agent, 0.5-1.5 parts dispersant, 10-20 parts deionized water, 20-25 parts curing agent, 0.1-0.5 parts organic zinc catalyst, and 0.5-1.2 parts foam stabilizer; (2) Stir and mix deionized water and dispersant, then add cement, calcium carbonate and nano titanium dioxide in sequence, heat and stir until mixed, then add polyurethane emulsion, crosslinking agent, flame retardant and foaming agent and mix evenly to obtain component A; stir and mix curing agent, organic zinc catalyst and foam stabilizer to obtain component B; add component B to component A and stir until mixed to obtain modified polymer cement-based room temperature foaming fireproof coating.

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