Hydrolysis resistant flame retardant polyether polyols and methods for making the same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU LIHONG TECH DEV CO LTD
- Filing Date
- 2026-05-09
- Publication Date
- 2026-06-05
Smart Images
Figure CN122145757A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of reactive flame-retardant polyether polyols for polyurethane, and specifically to a hydrolysis-resistant flame-retardant polyether polyol and its preparation method. Background Technology
[0002] Polyether polyols are a crucial raw material for polyurethane materials, and their structure and composition directly impact subsequent processing and performance. For flame retardancy, existing technologies typically introduce phosphorus-containing structures into the polyol system to establish flame retardancy. For long-term stability, it's necessary to simultaneously consider hydrolysis resistance, storage stability, and viscosity control during processing. Publicly available information indicates that phosphorus-containing polyol routes can improve flame retardancy or hydrolysis resistance, but trade-offs remain between hydroxyl value, viscosity, and long-term stability across different approaches. Particularly in scenarios requiring subsequent polyurethane molding, high system viscosity or insufficient moisture control often further compresses the processing window. Therefore, how to simultaneously introduce phosphorus-containing structures while maintaining a high hydroxyl value, moderate viscosity, and hydrolysis resistance remains a key technical challenge in this field.
[0003] In existing technologies, some solutions have attempted to balance flame retardancy and structural stability by constructing phosphorus-containing reactive polyols. For example, Chinese patent CN101747371A, "A Halogen-Free Flame-Retardant and Hydrolysis-Resistant Phosphorus-Containing Polyether / Polyester Polyol and Its Preparation Method," discloses a technical route to improve flame retardancy and hydrolysis resistance using a phosphorus-containing structure; Chinese patent CN113980264B, "A Preparation Method of a Flame-Retardant Polyether Polyol and Its Application," discloses a route to prepare a flame-retardant polyether polyol by reacting a phosphorus-containing reactive structure with propylene oxide and using it in polyurethane materials. From these disclosures, it can be seen that existing technologies have recognized the importance of reactive phosphorus-containing structures and provided several feasible routes; however, there is still room for further optimization regarding schemes that combine specific phosphorus-containing reactive polyether polyols with trihydroxy polyoxypropylene ether to achieve a more balanced match between higher hydroxyl value, moderate viscosity, low total sodium and potassium content, and hydrolysis resistance. Summary of the Invention
[0004] The purpose of this invention is to provide a hydrolysis-resistant flame-retardant polyether polyol and its preparation method, which solves the problems of existing phosphorus-containing reactive polyether polyols having easily increased viscosity, decreased fluidity, narrowed processing window, and insufficient hydrolysis stability while maintaining high hydroxyl value and reactivity during the flame retardancy enhancement process.
[0005] This invention achieves a synergistic balance among hydroxyl value, viscosity at 25°C, acid value, moisture content, total sodium and potassium content, and hydrolysis resistance test indicators by compounding trihydroxy polyoxypropylene ether with phosphorus-containing reactive polyether polyol, and by controlling the processes of intermediate I, intermediate II, first-stage propylene oxide, second-stage propylene oxide, neutralization, vacuum devolatilization, and filtration.
[0006] Technical solution
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] A hydrolysis-resistant flame-retardant polyether polyol comprises component A and component B; component A is trihydroxy polyoxypropylene ether; component B is a phosphorus-containing reactive polyether polyol, wherein the phosphorus-containing reactive polyether polyol is prepared by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diethanolamine and paraformaldehyde, followed by reaction with propylene oxide; the mass ratio of component A to component B is 1.8:1 to 3.8:1; the hydroxyl value of the hydrolysis-resistant flame-retardant polyether polyol is 250 mg KOH / g to 450 mg KOH / g, and the viscosity at 25°C is 1200 mPa·s to 4500 mPa·s.
[0009] Furthermore, the preparation of component B includes the following steps for preparing intermediate I:
[0010] A1, providing raw materials, wherein 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100 parts by weight, diethanolamine is 35 to 55 parts by weight, and paraformaldehyde is 10 to 20 parts by weight.
[0011] A2, react the raw materials provided in step A1 at 80°C to 100°C for 4 to 6 hours under nitrogen protection;
[0012] A3, dehydrate the reaction solution obtained in step A2 at 90℃ to 110℃ and a gauge pressure of -0.095MPa to -0.08MPa for 0.5h to 2h;
[0013] A4 yields intermediate I with a moisture content of no more than 0.20 wt%.
[0014] Furthermore, the preparation of component B further includes the following steps for preparing intermediate II:
[0015] B1, mix intermediate I with potassium hydroxide, wherein the amount of potassium hydroxide is 0.05 to 0.30 parts by mass relative to 100 parts by mass of intermediate I;
[0016] B2 was vacuum dried at 100℃ to 120℃ for 0.5h to 1.5h to ensure that the moisture content of the system was no more than 0.05wt%.
[0017] B3. Add the first propylene oxide to the system obtained in step B2. The mass ratio of the first propylene oxide to intermediate I is 0.10:1 to 0.40:1. React for 2 to 6 hours at 100°C to 120°C and a gauge pressure of 0.20 MPa to 0.50 MPa.
[0018] B4 yields intermediate II with a hydroxyl value ranging from 250 mg KOH / g to 400 mg KOH / g.
[0019] Furthermore, component B is prepared from intermediate II according to the following steps:
[0020] C1, reacting intermediate II with propylene oxide in a mass ratio of propylene oxide to intermediate II of 1.0:1 to 4.0:1;
[0021] C2, the reaction is carried out at 105°C to 125°C and a gauge pressure of 0.25 MPa to 0.60 MPa for 3 to 8 hours;
[0022] C3, after the reaction is complete, phosphoric acid is added for neutralization;
[0023] C4 was used to devolve the neutralized system under vacuum at 95°C to 110°C for 0.5 h to 2 h, and then filtered through a filter with a pore size of 1 μm to 10 μm.
[0024] C5 yields component B with a hydroxyl value of 150 mg KOH / g to 200 mg KOH / g and a moisture content of no more than 0.05 wt%.
[0025] Furthermore, the hydrolysis-resistant flame-retardant polyether polyol is prepared through the following steps:
[0026] D1, mix component A and component B at a mass ratio of 1.8:1 to 3.8:1 at 60°C to 90°C under nitrogen protection for 0.5h to 2h;
[0027] D2, the mixture obtained from D1 is vacuum devolatilized at 90°C to 110°C for 0.5 h to 1.5 h;
[0028] D3, the product obtained from D2 is filtered through a filter with a pore size of 1 μm to 5 μm;
[0029] D4 yields the hydrolysis-resistant flame-retardant polyether polyol with an acid value of no more than 0.08 mg KOH / g, a moisture content of no more than 0.08 wt%, and a total sodium and potassium content of no more than 10 mg / kg.
[0030] Furthermore, component B is a phosphorus-containing reactive polyether polyol prepared by adding propylene oxide in two stages, wherein the mass fraction of the first stage propylene oxide feed relative to the total propylene oxide feed is 10wt% to 22wt%, the mass fraction of the second stage propylene oxide feed relative to the total propylene oxide feed is 78wt% to 90wt%, and the sum of the first stage propylene oxide feed and the second stage propylene oxide feed is 100wt%.
[0031] Furthermore, component A has a hydroxyl value of 320 mg KOH / g to 450 mg KOH / g, a viscosity of 300 mPa·s to 1500 mPa·s at 25°C, and a moisture content of no more than 0.05 wt%.
[0032] Furthermore, after the hydrolysis-resistant flame-retardant polyether polyol is soaked in deionized water at 70±2℃ for 168h, the hydroxyl value retention rate is not less than 95%, the relative increase in viscosity at 25℃ is not greater than 12%, and the increase in acid value is not greater than 0.03mgKOH / g.
[0033] As a concept of this invention, trihydroxy polyoxypropylene ether is used as component A, and a phosphorus-containing reactive polyether polyol, prepared by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diethanolamine, and paraformaldehyde followed by reaction with propylene oxide, is used as component B. The mass ratio of component A to component B, the hydroxyl value, and the viscosity at 25°C are controlled to ensure that the hydrolysis-resistant flame-retardant polyether polyol simultaneously possesses phosphorus-containing segments, polyoxypropylene segments, and a hydroxyl value window suitable for polyurethane molding. Through this design, the viscosity, acid value, moisture content at 25°C, as well as the hydroxyl value retention rate, relative viscosity increase, and acid value increase after hydrolysis resistance testing, can be balanced in the hydrolysis-resistant flame-retardant polyether polyol.
[0034] This invention also discloses a method for preparing a hydrolysis-resistant flame-retardant polyether polyol, comprising the following steps:
[0035] S1, prepare component B, wherein component B is a phosphorus-containing reactive polyether polyol prepared by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diethanolamine and paraformaldehyde, and then reacting it with propylene oxide.
[0036] S2 provides trihydroxy polyoxypropylene ether as component A;
[0037] S3, mix component A and component B at a mass ratio of 1.8:1 to 3.8:1 at 60°C to 90°C under nitrogen protection for 0.5h to 2h;
[0038] S4, the mixture obtained in S3 is vacuum devolatilized at 90°C to 110°C for 0.5 h to 1.5 h;
[0039] S5. The product obtained in S4 is filtered through a filter with a pore size of 1μm to 5μm to obtain a hydrolysis-resistant flame-retardant polyether polyol with an acid value of no more than 0.08mgKOH / g, a moisture content of no more than 0.08wt%, and a total sodium and potassium content of no more than 10mg / kg.
[0040] Furthermore, component B prepared in S1 is a phosphorus-containing reactive polyether polyol obtained by adding propylene oxide in two stages. The mass fraction of the first stage propylene oxide feed relative to the total propylene oxide feed is 10wt% to 22wt%, and the mass fraction of the second stage propylene oxide feed relative to the total propylene oxide feed is 78wt% to 90wt%. The sum of the first stage propylene oxide feed and the second stage propylene oxide feed is 100wt%.
[0041] Furthermore, the amount of paraformaldehyde used in the preparation of intermediate I is calculated based on the repeating unit —CH2O—.
[0042] Furthermore, the purity of nitrogen gas is not less than 99.5%.
[0043] Furthermore, nitrogen protection is achieved by evacuating the atmosphere and replacing it with nitrogen two to four times before the reaction, and maintaining nitrogen sealing during the reaction.
[0044] Furthermore, the gauge pressure for the vacuum drying or vacuum devouring step is -0.095 MPa to -0.08 MPa.
[0045] Furthermore, the step of adding propylene oxide is carried out in a pressure-resistant reactor. First, the first stage of propylene oxide is added and reacted, and then the second stage of propylene oxide is added. After the addition is completed, the reaction is kept at a constant temperature.
[0046] Furthermore, the amount of phosphoric acid added in the neutralization step is adjusted according to the amount of potassium hydroxide added.
[0047] Furthermore, after neutralization, the mixture is first vacuum-devoured until the residual volatile matter is no more than 0.5 wt%, and then filtered.
[0048] Furthermore, the hydrolysis resistance test was conducted in a closed container at 70±2℃. After the sample was in contact with deionized water at a constant mass ratio for 168h, the aqueous phase was separated first, and then the hydroxyl value, viscosity and acid value were measured separately.
[0049] Furthermore, the hydroxyl value retention rate is calculated by dividing the hydroxyl value after immersion by the hydroxyl value before immersion and then multiplying by 100%. The relative increase in viscosity is calculated by subtracting the viscosity before immersion from the viscosity after immersion, dividing by the viscosity before immersion, and then multiplying by 100%. The increase in acid value is calculated by subtracting the acid value before immersion from the acid value after immersion.
[0050] Furthermore, the hydroxyl value and acid value were determined by titration, the viscosity at 25°C was determined by rotational viscometer under uniform rotor and speed conditions, the moisture content was determined by Karl Fischer method, and the total phosphorus content and the total sodium and potassium content were determined by elemental analysis.
[0051] Furthermore, the phosphorus-containing segments and polyoxypropylene segments were characterized using hydrogen nuclear magnetic resonance spectroscopy, phosphorus nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and gel permeation chromatography.
[0052] As another aspect of this invention, the preparation method first prepares component B, then provides component A, and mixes them under nitrogen protection at a defined mass ratio, followed by vacuum devolatilization and filtration. By controlling the coordination of intermediate I, intermediate II, the first stage of propylene oxide, the second stage of propylene oxide, potassium hydroxide, and phosphoric acid neutralization steps, the resulting hydrolysis-resistant flame-retardant polyether polyol meets the requirements for hydroxyl value, viscosity at 25°C, acid value, moisture content, and total sodium and potassium content. Furthermore, it helps maintain the hydroxyl value retention rate, relative viscosity increase, and acid value increase within defined ranges after hydrolysis resistance testing.
[0053] Component A provides the polyoxypropylene segments and hydroxyl value, while component B provides the phosphorus-containing segments and hydroxyl value. Insufficient component B results in insufficient phosphorus-containing segments; excessive component B leads to a higher viscosity at 25°C and increases the difficulty of controlling moisture, acid value, and total sodium and potassium content. Maintaining a component A to component B ratio of 1.8:1 to 3.8:1, combined with nitrogen protection, vacuum devolatilization, phosphoric acid neutralization, and filtration, allows the hydrolysis-resistant flame-retardant polyether polyol to simultaneously achieve satisfactory hydroxyl value, viscosity at 25°C, moisture content, acid value, and hydrolysis resistance test indicators.
[0054] Beneficial technical effects
[0055] 1. This invention constructs a hydrolysis-resistant and flame-retardant polyether polyol by compounding component A and component B, so that phosphorus-containing segments and polyoxypropylene segments coexist in the same system. This is beneficial for taking into account both the introduction of phosphorus-containing structures and the hydroxyl value window required for polyurethane molding, and reduces the problem that a single component cannot take into account multiple performance indicators.
[0056] 2. By controlling intermediate I, intermediate II, and the first and second stages of propylene oxide stepwise, the formation process of component B can be adjusted in stages, which is beneficial to controlling the hydroxyl value and viscosity at 25°C of the hydrolysis-resistant flame-retardant polyether polyol within the applicable range.
[0057] 3. Through nitrogen protection, vacuum drying, vacuum devolatilization, phosphoric acid neutralization and filtration, this invention can further control the moisture, acid value and total sodium and potassium content, which is beneficial to improving the storage stability and subsequent use stability of hydrolysis resistant flame retardant polyether polyols.
[0058] 4. This invention introduces hydroxyl value retention rate, relative viscosity increase at 25°C, and acid value increase as hydrolysis resistance test indicators, so that the stability evaluation of hydrolysis-resistant flame-retardant polyether polyols can be correlated with component ratio and preparation method, which facilitates the verification and comparison of technical solutions. Attached Figure Description
[0059] Figure 1 The graphs show the molecular weight distribution of GPC in Example 1, Comparative Example 1, and Comparative Example 2.
[0060] Figure 2 This is a comparison chart of the number-average molecular weights of Example 1, Comparative Example 1, and Comparative Example 2.
[0061] Figure 3 This is a comparison chart of the weight-average molecular weights of Example 1, Comparative Example 1, and Comparative Example 2.
[0062] Figure 4 This is a comparison chart of the molecular weight distribution coefficients of Example 1, Comparative Example 1, and Comparative Example 2.
[0063] Figure 5 The graph shows the hydroxyl value retention rate of Example 1, Comparative Example 1, and Comparative Example 2 under hydrolysis resistance conditions at 70°C.
[0064] Figure 6 The graph shows the relative increase in viscosity of Example 1, Comparative Example 1, and Comparative Example 2 under hydrolysis-resistant conditions at 70°C.
[0065] Figure 7 The graph shows the increase in acid value of Example 1, Comparative Example 1, and Comparative Example 2 under hydrolysis-resistant conditions at 70°C.
[0066] Figure 8 The images show the 31P NMR superimposed spectra of Example 1, Comparative Example 6, and Comparative Example 10.
[0067] Figure 9 The diagram shows the area ratio of the primary and secondary phosphorus environmental peaks for Example 1, Comparative Example 6, and Comparative Example 10.
[0068] Figure 10 FTIR characteristic region superimposed spectra of Example 1 and Comparative Example 10 (1000–1300 cm⁻¹) -1 ).
[0069] Figure 11 This is a macroscopic optical photograph of the hydrolysis-resistant flame-retardant polyether polyol of Example 1.
[0070] Figure 12 The image shows a scanning electron microscope (SEM) image of the rigid polyurethane foam prepared from the polyether polyol in Example 1.
[0071] Figure 13The images shown are transmission electron microscopy (TEM) images of the polyether polyol and its polyurethane derivatives from Example 1. Figure 13 a is a bright-field plot of the dried polyether solution sample. Figure 13 b is a microphase separation morphology diagram of the phosphorus-containing hard segments and the polyoxypropylene matrix. Figure 13 c is a high-resolution image of an ultrathin section of rigid polyurethane foam. Figure 13 d is the selected area electron diffraction pattern. Detailed Implementation
[0072] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.
[0073] Example 1
[0074] Step 1: Preparation of Intermediate I
[0075] In a reactor equipped with a stirrer, thermometer, and nitrogen protection system, 100 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 45 parts by mass of diethanolamine, and 15 parts by mass of paraformaldehyde (the amount of paraformaldehyde is based on repeating CH2O- units) were added. Before the reaction, the system was evacuated and purged with nitrogen three times, using nitrogen gas with a purity of not less than 99.5%. Under nitrogen protection (maintaining nitrogen sealing during the reaction), the reaction system was heated to 90°C and maintained for 5 hours. After the reaction, the resulting reaction solution was dehydrated for 1 hour at 100°C and a gauge pressure of -0.09 MPa to obtain intermediate I with a water content of 0.15 wt%.
[0076] Step 2: Preparation of Intermediate II
[0077] Intermediate I obtained in step one was mixed with potassium hydroxide, with the amount of potassium hydroxide being 0.18 parts by mass relative to 100 parts by mass of intermediate I. The mixture was vacuum dried at 110°C for 1 hour to reduce the moisture content of the system to 0.03 wt%. The dried system was transferred to a pressure reactor, and 25 parts by mass of the first-stage propylene oxide (the mass ratio of the first-stage propylene oxide to intermediate I was 0.25:1) were added. The mixture was reacted at 110°C and a gauge pressure of 0.35 MPa for 4 hours to obtain intermediate II with a hydroxyl value of 325 mg KOH / g.
[0078] Step 3: Preparation of component B
[0079] Based on intermediate II obtained in step two, 131.25 parts by mass of the second-stage propylene oxide (the mass ratio of the second-stage propylene oxide to intermediate II is 1.05:1) were added, and the reaction was carried out at 115℃ and a gauge pressure of 0.42 MPa for 5.5 h. After the addition was completed, the reaction was continued at this temperature. After the reaction was completed, phosphoric acid was added according to the amount of potassium hydroxide added for neutralization. The neutralized system was then vacuum-devoured at 102℃ until the residual volatile matter was 0.3 wt%, the gauge pressure was -0.09 MPa, and the devouring time was 1 h. Subsequently, the mixture was filtered through a 5 μm filter to obtain component B with a hydroxyl value of 175 mg KOH / g and a water content of 0.03 wt%. In this embodiment, the amount of propylene oxide fed in the first stage is 25 parts by mass, the amount of propylene oxide fed in the second stage is 131.25 parts by mass, and the total amount of propylene oxide fed is 156.25 parts by mass. The mass fraction of the amount of propylene oxide fed in the first stage relative to the total amount of propylene oxide fed is 16 wt%, and the mass fraction of the amount of propylene oxide fed in the second stage relative to the total amount of propylene oxide fed is 84 wt%.
[0080] Step 4: Preparation of component A
[0081] Trihydroxy polyoxypropylene ether was used as component A. In this embodiment, component A has a hydroxyl value of 385 mg KOH / g, a viscosity of 900 mPa·s at 25°C, and a water content of 0.03 wt%.
[0082] Step 5: Preparation of hydrolysis-resistant flame-retardant polyether polyol
[0083] Component A from step four and component B from step three were mixed at a mass ratio of 2.8:1 in a mixing vessel equipped with a stirrer and a nitrogen protection system. Before the reaction, the mixture was evacuated and purged with nitrogen three times. The mixture was then mixed at 75°C under nitrogen protection (maintaining nitrogen sealing during the reaction) for 1 hour. The resulting mixture was then vacuum-devoured at 100°C for 1 hour, with a gauge pressure of -0.09 MPa. The devoured product was filtered through a 3 μm filter to obtain the hydrolysis-resistant flame-retardant polyether polyol of this embodiment.
[0084] Product Performance
[0085] The hydrolysis-resistant and flame-retardant polyether polyol obtained in this embodiment has a hydroxyl value of 330 mg KOH / g, a viscosity of 2850 mPa·s at 25°C, an acid value of 0.05 mg KOH / g, a moisture content of 0.05 wt%, and a total sodium and potassium content of 6 mg / kg. The hydroxyl and acid values were determined by titration, the viscosity at 25°C was determined using a rotational viscometer under uniform rotor and speed conditions, the moisture content was determined by the Karl Fischer method, and the total sodium and potassium content was determined by elemental analysis. The phosphorus-containing segment and the polyoxypropylene segment were characterized by proton nuclear magnetic resonance (NMR), phosphorus nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and gel permeation chromatography, confirming the product structure.
[0086] The hydrolysis-resistant flame-retardant polyether polyol sample of this embodiment was contacted with deionized water at a constant mass ratio in a sealed container at 70±2℃ for 168 hours. The aqueous phase was first separated, and then the hydroxyl value, viscosity, and acid value were measured. After immersion, the hydroxyl value was 316 mgKOH / g, with a hydroxyl value retention rate of 95.8% (calculated by dividing the hydroxyl value after immersion by the hydroxyl value before immersion and then multiplying by 100%). The viscosity at 25℃ was 3150 mPa·s, with a relative viscosity increase of 10.5% (calculated by subtracting the viscosity before immersion from the viscosity after immersion, dividing by the viscosity before immersion, and then multiplying by 100%). The acid value was 0.08 mgKOH / g, with an acid value increase of 0.03 mgKOH / g (calculated by subtracting the acid value before immersion from the acid value after immersion).
[0087] This embodiment is applicable to polyurethane rigid foam and semi-rigid foam fields where high requirements are placed on process stability and product consistency. It is particularly suitable for applications requiring long-term hydrolysis resistance, such as building insulation materials and cold chain equipment insulation layers.
[0088] Example 2
[0089] Step 1: Preparation of Intermediate I
[0090] In a reactor equipped with a stirrer, thermometer, and nitrogen protection system, 100 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 40 parts by mass of diethanolamine, and 12 parts by mass of paraformaldehyde (the amount of paraformaldehyde is based on repeating CH2O- units) were added. Before the reaction, the system was evacuated and purged with nitrogen three times, using nitrogen gas with a purity of not less than 99.5%. Under nitrogen protection (maintaining nitrogen sealing during the reaction), the reaction system was heated to 85°C and maintained for 4.5 hours. After the reaction, the resulting reaction solution was dehydrated for 1.2 hours at 95°C and a gauge pressure of -0.09 MPa to obtain intermediate I with a water content of 0.12 wt%.
[0091] Step 2: Preparation of Intermediate II
[0092] Intermediate I obtained in step one was mixed with potassium hydroxide, with the amount of potassium hydroxide being 0.12 parts by mass relative to 100 parts by mass of intermediate I. The mixture was vacuum dried at 105°C for 1.2 h to reduce the moisture content of the system to 0.04 wt%. The dried system was transferred to a pressure-resistant reactor, and 18 parts by mass of the first-stage propylene oxide (the mass ratio of the first-stage propylene oxide to intermediate I was 0.18:1) were added. The mixture was reacted at 105°C and a gauge pressure of 0.30 MPa for 3 h to obtain intermediate II with a hydroxyl value of 355 mg KOH / g.
[0093] Step 3: Preparation of component B
[0094] Based on intermediate II obtained in step two, 132 parts by mass of the second-stage propylene oxide (the mass ratio of the second-stage propylene oxide to intermediate II is 1.12:1) were added, and the reaction was carried out at 110℃ and a gauge pressure of 0.38 MPa for 4.5 h. After the addition was completed, the reaction was continued at this temperature. After the reaction was completed, phosphoric acid was added according to the amount of potassium hydroxide added for neutralization. The neutralized system was then vacuum-devoured at 98℃ until the residual volatile matter was 0.4 wt%, the gauge pressure was -0.09 MPa, and the devouring time was 1.2 h. Subsequently, it was filtered through a filter with a pore size of 3 μm to obtain component B with a hydroxyl value of 185 mg KOH / g and a water content of 0.04 wt%. In this embodiment, the amount of propylene oxide fed in the first stage is 18 parts by mass, the amount of propylene oxide fed in the second stage is 132 parts by mass, and the total amount of propylene oxide fed is 150 parts by mass. The mass fraction of the amount of propylene oxide fed in the first stage relative to the total amount of propylene oxide fed is 12 wt%, and the mass fraction of the amount of propylene oxide fed in the second stage relative to the total amount of propylene oxide fed is 88 wt%.
[0095] Step 4: Preparation of component A
[0096] Trihydroxy polyoxypropylene ether was used as component A. In this embodiment, component A has a hydroxyl value of 420 mg KOH / g, a viscosity of 650 mPa·s at 25°C, and a water content of 0.02 wt%.
[0097] Step 5: Preparation of hydrolysis-resistant flame-retardant polyether polyol
[0098] Component A from step four and component B from step three were mixed at a mass ratio of 2.2:1 in a mixing vessel equipped with a stirrer and a nitrogen protection system. Before the reaction, the mixture was evacuated and purged with nitrogen three times. The mixture was then mixed at 70°C under nitrogen protection (maintaining nitrogen sealing during the reaction) for 1.2 hours. The resulting mixture was then vacuum-devoured at 95°C for 1.2 hours, with a gauge pressure of -0.09 MPa. The devoured product was filtered through a 2 μm filter to obtain the hydrolysis-resistant flame-retardant polyether polyol of this embodiment.
[0099] Product Performance
[0100] The hydrolysis-resistant and flame-retardant polyether polyol obtained in this embodiment has a hydroxyl value of 347 mgKOH / g, a viscosity of 1950 mPa·s at 25°C, an acid value of 0.04 mgKOH / g, a moisture content of 0.04 wt%, and a total sodium and potassium content of 5 mg / kg. The hydroxyl and acid values were determined by titration, the viscosity at 25°C was determined using a rotational viscometer under uniform rotor and speed conditions, the moisture content was determined by the Karl Fischer method, and the total sodium and potassium content was determined by elemental analysis. The phosphorus-containing segment and the polyoxypropylene segment were characterized by proton nuclear magnetic resonance (NMR), phosphorus nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and gel permeation chromatography, confirming the product structure.
[0101] The hydrolysis-resistant flame-retardant polyether polyol sample of this embodiment was contacted with deionized water at a constant mass ratio in a sealed container at 70±2℃ for 168 hours. The aqueous phase was first separated, and then the hydroxyl value, viscosity, and acid value were measured. After immersion, the hydroxyl value was 332 mgKOH / g, with a hydroxyl value retention rate of 95.8% (calculated by dividing the hydroxyl value after immersion by the hydroxyl value before immersion and then multiplying by 100%). The viscosity at 25℃ was 2170 mPa·s, with a relative viscosity increase of 11.3% (calculated by subtracting the viscosity before immersion from the viscosity after immersion, dividing by the viscosity before immersion, and then multiplying by 100%). The acid value was 0.06 mgKOH / g, with an acid value increase of 0.02 mgKOH / g (calculated by subtracting the acid value before immersion from the acid value after immersion).
[0102] This embodiment adopts a formulation design that favors high hydroxyl values, which is suitable for rapid prototyping polyurethane foam, sprayed polyurethane foam and other fields with high requirements for reactivity. It is especially suitable for application scenarios such as on-site foaming construction and integrated thermal insulation and waterproofing systems that require rapid curing.
[0103] Example 3
[0104] Step 1: Preparation of Intermediate I
[0105] In a reactor equipped with a stirrer, thermometer, and nitrogen protection system, 100 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 50 parts by mass of diethanolamine, and 17 parts by mass of paraformaldehyde (the amount of paraformaldehyde is based on repeating CH2O- units) were added. Before the reaction, the system was evacuated and purged with nitrogen four times, using nitrogen gas with a purity of not less than 99.5%. Under nitrogen protection (maintaining nitrogen sealing during the reaction), the reaction system was heated to 95°C and maintained for 5.5 hours. After the reaction, the resulting reaction solution was dehydrated for 0.8 hours at 105°C and a gauge pressure of -0.088 MPa to obtain intermediate I with a water content of 0.10 wt%.
[0106] Step 2: Preparation of Intermediate II
[0107] Intermediate I obtained in step one was mixed with potassium hydroxide, with the amount of potassium hydroxide being 0.25 parts by mass relative to 100 parts by mass of intermediate I. The mixture was vacuum dried at 115°C for 0.8 h to reduce the moisture content of the system to 0.02 wt%. The dried system was transferred to a pressure-resistant reactor, and 30 parts by mass of the first-stage propylene oxide (the mass ratio of the first-stage propylene oxide to intermediate I was 0.30:1) was added. The mixture was reacted at 115°C and a gauge pressure of 0.45 MPa for 5 h to obtain intermediate II with a hydroxyl value of 280 mg KOH / g.
[0108] Step 3: Preparation of component B
[0109] Based on intermediate II obtained in step two, 170 parts by mass of the second-stage propylene oxide (the mass ratio of the second-stage propylene oxide to intermediate II is 1.31:1) were added, and the reaction was carried out at 120℃ and a gauge pressure of 0.52 MPa for 6.5 h. After the addition was completed, the reaction was continued at this temperature. After the reaction was completed, phosphoric acid was added according to the amount of potassium hydroxide added for neutralization. The neutralized system was then vacuum-devoured at 105℃ until the residual volatile matter was 0.2 wt%, the gauge pressure was -0.088 MPa, and the devouring time was 0.8 h. Subsequently, it was filtered through a filter with a pore size of 7 μm to obtain component B with a hydroxyl value of 160 mg KOH / g and a water content of 0.02 wt%. In this embodiment, the amount of propylene oxide fed in the first stage is 30 parts by mass, the amount of propylene oxide fed in the second stage is 170 parts by mass, and the total amount of propylene oxide fed is 200 parts by mass. The mass fraction of the amount of propylene oxide fed in the first stage relative to the total amount of propylene oxide fed is 15 wt%, and the mass fraction of the amount of propylene oxide fed in the second stage relative to the total amount of propylene oxide fed is 85 wt%.
[0110] Step 4: Preparation of component A
[0111] Trihydroxy polyoxypropylene ether was used as component A. In this embodiment, component A has a hydroxyl value of 340 mg KOH / g, a viscosity of 1350 mPa·s at 25°C, and a water content of 0.04 wt%.
[0112] Step 5: Preparation of hydrolysis-resistant flame-retardant polyether polyol
[0113] Component A from step four and component B from step three were mixed at a mass ratio of 3.2:1 in a mixing vessel equipped with a stirrer and a nitrogen protection system. Before the reaction, the mixture was evacuated and purged with nitrogen three times. The mixture was then mixed at 82°C under nitrogen protection (maintaining nitrogen sealing during the reaction) for 0.8 hours. The resulting mixture was then vacuum-devoured at 105°C for 0.8 hours, with a gauge pressure of -0.088 MPa. The devoured product was filtered through a 4 μm filter to obtain the hydrolysis-resistant flame-retardant polyether polyol of this embodiment.
[0114] Product Performance
[0115] The hydrolysis-resistant and flame-retardant polyether polyol obtained in this embodiment has a hydroxyl value of 297 mg KOH / g, a viscosity of 3650 mPa·s at 25°C, an acid value of 0.06 mg KOH / g, a moisture content of 0.06 wt%, and a total sodium and potassium content of 7 mg / kg. The hydroxyl and acid values were determined by titration, the viscosity at 25°C was determined using a rotational viscometer under uniform rotor and speed conditions, the moisture content was determined by the Karl Fischer method, and the total sodium and potassium content was determined by elemental analysis. The phosphorus-containing segment and the polyoxypropylene segment were characterized by proton nuclear magnetic resonance (NMR), phosphorus nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and gel permeation chromatography, confirming the product structure.
[0116] The hydrolysis-resistant flame-retardant polyether polyol sample of this embodiment was contacted with deionized water at a constant mass ratio in a sealed container at 70±2℃ for 168 hours. The aqueous phase was first separated, and then the hydroxyl value, viscosity, and acid value were measured. After immersion, the hydroxyl value was 283 mgKOH / g, with a hydroxyl value retention rate of 95.3% (calculated by dividing the hydroxyl value after immersion by the hydroxyl value before immersion and then multiplying by 100%). The viscosity at 25℃ was 4070 mPa·s, with a relative viscosity increase of 11.5% (calculated by subtracting the viscosity before immersion from the viscosity after immersion, dividing by the viscosity before immersion, and then multiplying by 100%). The acid value was 0.09 mgKOH / g, with an acid value increase of 0.03 mgKOH / g (calculated by subtracting the acid value before immersion from the acid value after immersion).
[0117] This embodiment employs a formulation design biased towards low hydroxyl value and high viscosity, achieving a hydroxyl value retention rate of 95.3%, a viscosity increase of 11.5%, and an acid value increase of 0.03 mg KOH / g. It is suitable for applications requiring high material flexibility and low crosslinking density, such as semi-rigid foams and elastomers, and is particularly well-suited for automotive interior parts, upholstered furniture, and elastic sealing materials—applications demanding good flexibility and weather resistance.
[0118] Example 4
[0119] Step 1: Preparation of Intermediate I
[0120] In a reactor equipped with a stirrer, thermometer, and nitrogen protection system, 100 parts by mass of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 37 parts by mass of diethanolamine, and 19 parts by mass of paraformaldehyde (the amount of paraformaldehyde is based on repeating CH2O- units) were added. Before the reaction, the system was evacuated and purged twice with nitrogen gas of at least 99.5% purity. Under nitrogen protection (maintaining nitrogen sealing during the reaction), the reaction system was heated to 98°C and maintained for 4.2 hours. After the reaction, the resulting reaction solution was dehydrated for 0.6 hours at 108°C and a gauge pressure of -0.082 MPa to obtain intermediate I with a water content of 0.08 wt%.
[0121] Step 2: Preparation of Intermediate II
[0122] Intermediate I obtained in step one was mixed with potassium hydroxide, with the amount of potassium hydroxide being 0.28 parts by mass relative to 100 parts by mass of intermediate I. The mixture was vacuum dried at 118°C for 0.6 h to reduce the moisture content of the system to 0.01 wt%. The dried system was transferred to a pressure reactor, and 38 parts by mass of the first-stage propylene oxide (the mass ratio of the first-stage propylene oxide to intermediate I was 0.38:1) were added. The mixture was reacted at 118°C and a gauge pressure of 0.48 MPa for 2.5 h to obtain intermediate II with a hydroxyl value of 265 mg KOH / g.
[0123] Step 3: Preparation of component B
[0124] Based on intermediate II obtained in step two, 143 parts by mass of the second-stage propylene oxide (the mass ratio of the second-stage propylene oxide to intermediate II is 1.04:1) were added, and the reaction was carried out at 122℃ and a gauge pressure of 0.56 MPa for 7.5 h. After the addition was completed, the reaction was continued at this temperature. After the reaction was completed, phosphoric acid was added according to the amount of potassium hydroxide added for neutralization. The neutralized system was then vacuum-devoured at 108℃ until the residual volatile matter was 0.1 wt%, the gauge pressure was -0.082 MPa, and the devouring time was 0.6 h. Subsequently, it was filtered through a filter with a pore size of 9 μm to obtain component B with a hydroxyl value of 155 mg KOH / g and a water content of 0.01 wt%. In this embodiment, the amount of propylene oxide fed in the first stage is 38 parts by mass, the amount of propylene oxide fed in the second stage is 143 parts by mass, and the total amount of propylene oxide fed is 181 parts by mass. The mass fraction of the amount of propylene oxide fed in the first stage relative to the total amount of propylene oxide fed is 21 wt%, and the mass fraction of the amount of propylene oxide fed in the second stage relative to the total amount of propylene oxide fed is 79 wt%.
[0125] Step 4: Preparation of component A
[0126] Trihydroxy polyoxypropylene ether was used as component A. In this embodiment, component A has a hydroxyl value of 330 mg KOH / g, a viscosity of 1450 mPa·s at 25°C, and a water content of 0.05 wt%.
[0127] Step 5: Preparation of hydrolysis-resistant flame-retardant polyether polyol
[0128] Component A from step four and component B from step three were mixed at a mass ratio of 3.6:1 in a mixing vessel equipped with a stirrer and a nitrogen protection system. Before the reaction, the mixture was evacuated and purged with nitrogen twice. The mixture was then mixed at 88°C under nitrogen protection (maintaining nitrogen sealing during the reaction) for 0.6 hours. The resulting mixture was then vacuum-devoured at 108°C for 0.6 hours, with a gauge pressure of -0.082 MPa. The devoured product was filtered through a 4.5 μm filter to obtain the hydrolysis-resistant flame-retardant polyether polyol of this embodiment.
[0129] Product Performance
[0130] The hydrolysis-resistant and flame-retardant polyether polyol obtained in this embodiment has a hydroxyl value of 292 mg KOH / g, a viscosity of 4150 mPa·s at 25°C, an acid value of 0.07 mg KOH / g, a moisture content of 0.07 wt%, and a total sodium and potassium content of 9 mg / kg. The hydroxyl and acid values were determined by titration, the viscosity at 25°C was determined using a rotational viscometer under uniform rotor and speed conditions, the moisture content was determined by the Karl Fischer method, and the total sodium and potassium content was determined by elemental analysis. The phosphorus-containing segment and the polyoxypropylene segment were characterized by proton nuclear magnetic resonance (NMR), phosphorus nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and gel permeation chromatography, confirming the product structure.
[0131] The hydrolysis-resistant flame-retardant polyether polyol sample of this embodiment was contacted with deionized water at a constant mass ratio in a sealed container at 70±2℃ for 168 hours. The aqueous phase was first separated, and then the hydroxyl value, viscosity, and acid value were measured. After immersion, the hydroxyl value was 278 mgKOH / g, with a hydroxyl value retention rate of 95.2% (calculated by dividing the hydroxyl value after immersion by the hydroxyl value before immersion and then multiplying by 100%). The viscosity at 25℃ was 4630 mPa·s, with a relative viscosity increase of 11.6% (calculated by subtracting the viscosity before immersion from the viscosity after immersion, dividing by the viscosity before immersion, and then multiplying by 100%). The acid value was 0.10 mgKOH / g, with an acid value increase of 0.03 mgKOH / g (calculated by subtracting the acid value before immersion from the acid value after immersion).
[0132] The product obtained in this embodiment exhibits excellent hydrolysis resistance, with a hydroxyl value retention rate of 95.2%, a viscosity increase of 11.6%, and an acid value increase of 0.03 mg KOH / g. It is suitable for specialized polyurethane systems with specific requirements for material viscosity and molecular weight, and is particularly well-suited for applications requiring high molecular weight and low hydroxyl values, such as high-viscosity sealants, high-molecular-weight elastomers, and thick-layer coatings.
[0133] Comparative Example 1: Basically the same as Example 1, except that in step five the mass ratio of component A to component B is adjusted to 1.6:1, and other conditions remain unchanged.
[0134] Comparative Example 2: It is basically the same as Example 1, except that in step five, the mass ratio of component A to component B is adjusted to 4.2:1, while other conditions remain unchanged.
[0135] Comparative Example 3: It is basically the same as Example 1, except that the amount of diethanolamine in step one is adjusted to 30 parts by mass, while other conditions remain unchanged.
[0136] Comparative Example 4: Basically the same as Example 1, except that the amount of paraformaldehyde in step one was adjusted to 22 parts by mass, while other conditions remained unchanged.
[0137] Comparative Example 5: It is basically the same as Example 1, except that the amount of potassium hydroxide in step 2 is adjusted to 0.35 parts by mass relative to 100 parts by mass of intermediate I, and other conditions remain unchanged.
[0138] Comparative Example 6: It is basically the same as Example 1, except that in steps two and three, the mass fraction of the first stage propylene oxide feed relative to the total propylene oxide feed is adjusted to 5 wt%, corresponding to 7.81 parts by mass of the first stage propylene oxide and 148.44 parts by mass of the second stage propylene oxide. Other conditions remain unchanged.
[0139] Comparative Example 7: Basically the same as Example 1, except that the vacuum devolatilization temperature in step five was adjusted to 85°C, while other conditions remained unchanged.
[0140] Comparative Example 8: Essentially the same as Example 1, except that only component A is used in step five, without adding component B. Other mixing, devolatilization, and filtration conditions remain unchanged. This comparative example is used to verify the synergistic effect of the combination of component A and component B.
[0141] Comparative Example 9: Essentially the same as Example 1, except that only component B is used in step five, without adding component A. Other devolatilization and filtration conditions remain unchanged. This comparative example is used to verify the synergistic effect of the combination of component A and component B.
[0142] Comparative Example 10: Essentially the same as Example 1, except that after vacuum drying in step two, propylene oxide was added all at once instead of in two stages. The reaction was carried out at 115°C and a gauge pressure of 0.42 MPa for 6.5 hours. After the reaction, neutralization, vacuum devolatilization, and filtration were performed as in Example 1, with all other conditions remaining unchanged. This comparative example was used to verify the synergistic effect of the staged addition of propylene oxide in the first and second stages.
[0143] Performance testing:
[0144] Experiment 1: For the hydrolysis-resistant flame-retardant polyether polyol samples of Examples 1-4 and the comparative examples, the acetylation back-tipping method was used to evaluate the product reactivity and functionality level. The hydroxyl value was calculated based on the amount of hydroxyl groups consumed in the sample. Samples were weighed after equilibration at 25°C, and the derivatization, back-tipping, and blank correction procedures were performed according to a unified procedure, with each group repeated in triplicate, following ASTM D4274. Results are output as mean ± standard deviation in mgKOH / g, and formulation correlation analysis was performed.
[0145] Experiment 2: For the samples from Examples 1-4 and the comparative example, the flowability and processing window at 25°C were evaluated using a rotational viscometer. After being held at 25 ± 0.2°C for 30 min, the apparent viscosity of the samples was measured under uniform rotor and rotational speed conditions. Each sample was tested in triplicate, and stable readings were recorded, following ASTM D4878. Results were output as mean ± standard deviation in mPa·s and analyzed in conjunction with hydroxyl value and total phosphorus content.
[0146] Experiment 3: For the samples from Examples 1-4 and the comparative example, the Karl Fischer volumetric method was used to evaluate the trace moisture control level. Samples were injected immediately after sealed sampling, with each group tested in triplicate and blank correction included. Moisture-proof operation was performed throughout, following ASTM E203. Results are output as mean ± standard deviation in wt%, and their correlation with hydrolysis resistance results was evaluated.
[0147] Experiment 4: The acid value and residual alkali metal control levels were evaluated for samples from Examples 1-4 and the comparative example. Acid value was determined using a standardized titration procedure, following ASTM D4662. Total sodium and potassium content was determined using ICP-OES. Samples underwent standardized digestion before analysis, referring to ASTM D5185 or similar ICP-OES elemental analysis standards. Acid value is expressed in mgKOH / g, and total sodium and potassium content in mg / kg. Each group was analyzed in triplicate. The mean ± standard deviation was output, and correlation analysis was performed with the increase in acid value after water immersion.
[0148] Experiment 5: For the samples from Examples 1-4 and the comparative example, the total phosphorus content was determined using ICP-OES to evaluate the degree of phosphorus-containing chain segment introduction, indirectly characterizing the basis of flame retardant function. Elemental analysis was performed on samples after treatment with a standardized digestion system, with each group analyzed in triplicate, according to ASTM D5185 or similar ICP-OES elemental analysis standards. Results are output as mean ± standard deviation in wt%, and are compared with hydroxyl value, viscosity, and hydrolytic stability.
[0149] Experiment 6: For the closed-loop contact systems of Examples 1-4 and the comparative sample with deionized water, the hydrolytic stability was verified by the changes in hydroxyl value, viscosity at 25℃, and acid value before and after water immersion, and the stability of the main chain and end groups under hot water conditions was evaluated. The samples and deionized water were placed in a closed container at a constant mass ratio and contacted at 70±2℃ for 24h, 72h, 120h, and 168h, respectively. After separating the aqueous phase, relevant indicators were tested, with each group tested in triplicate, referring to a combination of ASTM D4274, ASTM D4878, and ASTM D4662 methods. The hydroxyl value retention rate, relative viscosity increase, and acid value increase were calculated, and process curves were plotted.
[0150] Experiment 7: For the samples from Examples 1-4 and the comparative example, ATR-FTIR was used to confirm the characteristic absorptions of P=O, POC, and polyether COC, verifying the coexistence of phosphorus-containing segments and polyoxypropylene segments. Samples were collected at 4000 cm⁻¹. -1 Up to 600cm -1 Spectrum, resolution 4cm -1 A total of 32 scans were performed, following ASTM E1252, with uniform background subtraction and normalization. A CSV file was exported and 1260cm was calculated. -1 Nearby and 1100cm -1 The ratio of nearby peak areas is used for structural comparison.
[0151] Figure 1 The GPC molecular weight distribution curves for Example 1, Comparative Example 1, and Comparative Example 2 are shown. The molecular weight distribution of the samples was characterized by gel permeation chromatography. The differences in peak shape and distribution width under different compounding ratios were compared. The results showed that the distribution of Example 1 was more concentrated and the peak shape was more stable, indicating that component A and component B can form a more coordinated chain segment structure under appropriate ratios.
[0152] Figure 2 The graph shows a comparison of Mn values for Example 1, Comparative Example 1, and Comparative Example 2. The number-average molecular weight of the samples was determined by gel permeation chromatography and compared. The results show that the Mn value of Example 1 is in a more suitable range, indicating that the molecular chain growth process is more balanced under this ratio, which is beneficial for balancing reactivity and system stability.
[0153] Figure 3 The graph shows a comparison of the molecular weight (Mw) of Example 1, Comparative Example 1, and Comparative Example 2. The weight-average molecular weight of the samples was determined and analyzed by gel permeation chromatography. The results show that the Mw of Example 1 is maintained within a reasonable range, indicating that it avoids excessively short chain segments and inhibits excessive growth, demonstrating a good molecular structure regulation effect.
[0154] Figure 4 The PDI comparison charts for Example 1, Comparative Example 1, and Comparative Example 2 are shown. The molecular weight distribution coefficient was calculated by gel permeation chromatography and the differences between the different samples were compared. The results show that the PDI of Example 1 is lower and more uniformly distributed, indicating that an appropriate compounding ratio helps to improve the consistency of the system composition and structure.
[0155] Figure 5 The graphs show the hydroxyl value retention rates at 70°C for Examples 1, Comparative Examples 1 and 2. The retention rates of the samples at different time points were characterized by a 70°C hydrolysis resistance test combined with hydroxyl value determination. The results show that Example 1 has a higher retention rate throughout the entire process of 0 h, 24 h, 72 h, 120 h and 168 h, indicating that it has better structural stability in hot water environment.
[0156] Figure 6 The graphs show the relative increase in viscosity at 70°C for Examples 1, Comparative Examples 1 and 2. The rheological response of the samples over time was characterized by the viscosity test method under 70°C hydrolysis conditions. The results show that the viscosity increase in Example 1 is slower, indicating that the side reactions and structural degradation are more effectively suppressed under hydrothermal conditions.
[0157] Figure 7 The graphs show the increase in acid value at 70℃ for Examples 1, Comparative Examples 1 and 2. The degradation process of the samples was tracked by combining the 70℃ hydrolysis resistance test with the acid value determination method. The results show that the increase in acid value of Example 1 was always low, indicating that it had a weaker tendency to generate acidic substances by hydrolysis under hot water conditions and better overall stability.
[0158] Figure 8 The images show the 31P NMR superimposed spectra of Example 1, Comparative Example 6, and Comparative Example 10. The phosphorus chemical environment in the samples with different feeding methods was characterized by 31P nuclear magnetic resonance. The results show that the main peak of Example 1 is more concentrated and there are fewer impurity peaks, indicating that the phosphorus structure distribution is more uniform under the synergistic effect of segmented feeding and sequential feeding.
[0159] Figure 9 The peak area ratios of the primary and secondary phosphorus environments in Example 1, Comparative Example 6, and Comparative Example 10 are shown. The primary and secondary phosphorus environments were quantitatively compared using 31P nuclear magnetic resonance peak area integration. The results show that the primary and secondary peak area ratios in Example 1 are higher, indicating that its phosphorus environment is more concentrated and its structure is more ordered.
[0160] Figure 10 The FTIR characteristic region overlay spectra of Example 1 and Comparative Example 10 are 1000–1300 cm⁻¹. -1 Figure 1 shows that the characteristic absorption regions of P=O, P–O–C and C–O–C were characterized by Fourier transform infrared spectroscopy. The results show that Example 1 has better absorption synergy in the key characteristic regions, indicating that its phosphorus-containing structure and polyether segments are more reasonably matched.
[0161] Figure 11 This is a macroscopic optical photograph of the hydrolysis-resistant flame-retardant polyether polyol of Example 1. The sample is a homogeneous and transparent liquid, with no visible particles, obvious turbidity, or layering. This image is used to illustrate the appearance of the sample and is not intended as sole evidence of molecular-scale homogeneity, microphase separation, or adequate neutralization.
[0162] Figure 12 The images shown are scanning electron microscope images of the polyurethane rigid foam prepared by polyether polyol in Example 1. They are used to observe the cell morphology of the sample under the corresponding sample preparation conditions and are not intended as separate proof of DOPO group covalent anchoring, quantitative value of closed-cell rate, or uniformity of cell size.
[0163] Figure 13 The images shown are transmission electron microscopy (TEM) images of the polyether polyol and its polyurethane-based products from Example 1. Figure 13a is a bright-field image of the polyether sample under the corresponding sample preparation conditions, and Figures 13b to 13d are morphological images of the polyurethane-based products under the corresponding sample preparation conditions. This set of images is used to illustrate the electron microstructure of the samples and is not intended as sole evidence of molecular-scale compatible mixing, specific nanocluster sizes, or the absence of unreacted residues.
[0164] Table 1. Basic performance indicators of the embodiments and comparative examples.
[0165] Sample number Hydroxyl value (mgKOH / g) Viscosity at 25℃ (mPa·s) Acid value (mgKOH / g) Moisture (wt%) Total sodium and potassium content (mg / kg) Total phosphorus content (wt%) Example 1 330±4 2850±45 0.050±0.003 0.050±0.003 6±1 2.72±0.04 Example 2 347±5 1950±38 0.040±0.002 0.040±0.002 5±1 3.12±0.05 Example 3 297±4 3650±52 0.060±0.003 0.060±0.003 7±1 2.46±0.04 Example 4 292±3 4150±60 0.070±0.004 0.070±0.004 9±1 2.24±0.04 Comparative Example 1 304±5 3920±65 0.060±0.004 0.070±0.004 7±1 3.98±0.06 Comparative Example 2 345±6 2380±42 0.050±0.003 0.050±0.003 6±1 1.99±0.04 Comparative Example 3 321±5 2480±40 0.060±0.003 0.060±0.003 6±1 2.31±0.05 Comparative Example 4 337±5 3340±54 0.060±0.003 0.060±0.003 7±1 2.88±0.05 Comparative Example 5 349±4 2910±47 0.070±0.004 0.050±0.003 12±1 2.73±0.04 Comparative Example 6 357±5 3180±50 0.060±0.003 0.060±0.003 7±1 2.71±0.05 Comparative Example 7 347±4 2980±48 0.080±0.004 0.110±0.006 6±1 2.72±0.04 Comparative Example 8 385±5 900±25 0.030±0.002 0.030±0.002 2±1 0.00±0.00 Comparative Example 9 175±3 4680±72 0.060±0.003 0.030±0.002 5±1 10.34±0.08 Comparative Example 10 342±5 3320±53 0.060±0.003 0.060±0.003 7±1 2.70±0.05
[0166] Table 2 Hydrolysis Resistance Indicators
[0167]
[0168] As can be seen from the performance of the examples and comparative examples in Tables 1 and 2, Examples 1-4 all achieved a good balance between total phosphorus content, hydroxyl value, viscosity at 25°C, and hydrolysis resistance. Among them, Examples 1 and 2 showed the best overall performance, maintaining a total phosphorus content of over 2.72 wt%, a hydroxyl value retention rate of no less than 95.7%, and a relative viscosity increase controlled within 11.3%. Conventional comparative examples, after deviations in the compounding ratio, imbalances in raw material dosage, excessive catalyst, imbalances in the proportion of segmented propylene oxide, or insufficient post-treatment, typically exhibit imbalances in total phosphorus content, residual alkali metals, initial viscosity, and stability after water immersion. Although Comparative Example 8 performed well in some individual aspects, its total phosphorus content was close to zero; Comparative Example 9, although having a high total phosphorus content, showed a significant imbalance between hydroxyl value and viscosity; Comparative Example 10 demonstrated that after the segmented feeding structure was destroyed, the system still showed significant hydrolysis resistance degradation while maintaining a basically unchanged phosphorus content, indicating that the technical solution of this invention relies on the combined effect of compounding and segmented chain formation.
[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any equivalent structural transformations made under the concept of the present invention and using the contents of the specification and drawings of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A hydrolysis-resistant and flame-retardant polyether polyol, characterized in that, The product comprises component A and component B; component A is trihydroxy polyoxypropylene ether; component B is a phosphorus-containing reactive polyether polyol, which is prepared by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diethanolamine and paraformaldehyde, followed by reaction with propylene oxide; the mass ratio of component A to component B is 1.8:1 to 3.8:1; the hydrolysis-resistant flame-retardant polyether polyol has a hydroxyl value of 250 mg KOH / g to 450 mg KOH / g and a viscosity at 25°C of 1200 mPa·s to 4500 mPa·s.
2. The hydrolysis-resistant flame-retardant polyether polyol according to claim 1, characterized in that, The preparation of component B includes the following steps for preparing intermediate I: A1, providing raw materials, wherein 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100 parts by weight, diethanolamine is 35 to 55 parts by weight, and paraformaldehyde is 10 to 20 parts by weight. A2, react the raw materials provided in step A1 at 80°C to 100°C for 4 to 6 hours under nitrogen protection; A3, dehydrate the reaction solution obtained in step A2 at 90℃ to 110℃ and a gauge pressure of -0.095MPa to -0.08MPa for 0.5h to 2h; A4 yields intermediate I with a moisture content of no more than 0.20 wt%.
3. The hydrolysis-resistant flame-retardant polyether polyol according to claim 2, characterized in that, The preparation of component B further includes the following steps for preparing intermediate II: B1, mix intermediate I with potassium hydroxide, wherein the amount of potassium hydroxide is 0.05 to 0.30 parts by mass relative to 100 parts by mass of intermediate I; B2 was vacuum dried at 100℃ to 120℃ for 0.5h to 1.5h to ensure that the moisture content of the system was no more than 0.05wt%. B3. Add the first propylene oxide to the system obtained in step B2. The mass ratio of the first propylene oxide to intermediate I is 0.10:1 to 0.40:
1. React for 2 to 6 hours at 100°C to 120°C and a gauge pressure of 0.20 MPa to 0.50 MPa. B4 yields intermediate II with a hydroxyl value ranging from 250 mg KOH / g to 400 mg KOH / g.
4. The hydrolysis-resistant flame-retardant polyether polyol according to claim 3, characterized in that, Component B is prepared from intermediate II according to the following steps: C1, reacting intermediate II with propylene oxide in a mass ratio of propylene oxide to intermediate II of 1.0:1 to 4.0:1; C2, the reaction is carried out at 105°C to 125°C and a gauge pressure of 0.25 MPa to 0.60 MPa for 3 to 8 hours; C3, after the reaction is complete, phosphoric acid is added for neutralization; C4 was used to devolve the neutralized system under vacuum at 95°C to 110°C for 0.5 h to 2 h, and then filtered through a filter with a pore size of 1 μm to 10 μm. C5 yields component B with a hydroxyl value of 150 mg KOH / g to 200 mg KOH / g and a moisture content of no more than 0.05 wt%.
5. The hydrolysis-resistant flame-retardant polyether polyol according to claim 1, characterized in that, The hydrolysis-resistant and flame-retardant polyether polyol is prepared by the following steps: D1, mix component A and component B at a mass ratio of 1.8:1 to 3.8:1 at 60°C to 90°C under nitrogen protection for 0.5h to 2h; D2, the mixture obtained from D1 is vacuum devolatilized at 90°C to 110°C for 0.5 h to 1.5 h; D3, the product obtained from D2 is filtered through a filter with a pore size of 1 μm to 5 μm; D4 yields the hydrolysis-resistant flame-retardant polyether polyol with an acid value of no more than 0.08 mg KOH / g, a moisture content of no more than 0.08 wt%, and a total sodium and potassium content of no more than 10 mg / kg.
6. The hydrolysis-resistant flame-retardant polyether polyol according to claim 1, characterized in that, Component B is a phosphorus-containing reactive polyether polyol prepared by adding propylene oxide in two stages. The mass fraction of the first stage propylene oxide feed relative to the total propylene oxide feed is 10wt% to 22wt%, and the mass fraction of the second stage propylene oxide feed relative to the total propylene oxide feed is 78wt% to 90wt%. The sum of the first stage propylene oxide feed and the second stage propylene oxide feed is 100wt%.
7. The hydrolysis-resistant flame-retardant polyether polyol according to claim 1, characterized in that, The component A has a hydroxyl value of 320 mg KOH / g to 450 mg KOH / g, a viscosity of 300 mPa·s to 1500 mPa·s at 25°C, and a moisture content of no more than 0.05 wt%.
8. The hydrolysis-resistant flame-retardant polyether polyol according to claim 1, characterized in that, After being soaked in deionized water at 70±2℃ for 168 hours, the hydrolysis-resistant and flame-retardant polyether polyol retains a hydroxyl value of not less than 95%, a relative increase in viscosity at 25℃ of not more than 12%, and an increase in acid value of not more than 0.03 mg KOH / g.
9. A method for preparing a hydrolysis-resistant flame-retardant polyether polyol as described in any one of claims 1-8, characterized in that, Includes the following steps: S1, prepare component B, wherein component B is a phosphorus-containing reactive polyether polyol prepared by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diethanolamine and paraformaldehyde, and then reacting it with propylene oxide. S2 provides trihydroxy polyoxypropylene ether as component A; S3, mix component A and component B at a mass ratio of 1.8:1 to 3.8:1 at 60°C to 90°C under nitrogen protection for 0.5h to 2h; S4, the mixture obtained in S3 is vacuum devolatilized at 90°C to 110°C for 0.5 h to 1.5 h; S5. The product obtained in S4 is filtered through a filter with a pore size of 1μm to 5μm to obtain a hydrolysis-resistant flame-retardant polyether polyol with an acid value of no more than 0.08mgKOH / g, a moisture content of no more than 0.08wt%, and a total sodium and potassium content of no more than 10mg / kg.
10. The preparation method according to claim 9, characterized in that, Component B prepared in S1 is a phosphorus-containing reactive polyether polyol obtained by adding propylene oxide in two stages. The mass fraction of the first stage propylene oxide feed relative to the total propylene oxide feed is 10wt% to 22wt%, and the mass fraction of the second stage propylene oxide feed relative to the total propylene oxide feed is 78wt% to 90wt%. The sum of the first stage propylene oxide feed and the second stage propylene oxide feed is 100wt%.