Reactive flame-retardant polyether polyol and preparation method thereof

Abstract

The invention belongs to the technical field of polyurethane raw materials, and provides reactive flame-retardant polyether polyol and a preparation method thereof. According to the invention, phosphamide diol and triethanolamine are adopted to co-initiate ring opening polymerization of epoxypropane, phosphorus pentoxide / phosphoric acid esterification is carried out, and then triethanolamine is adopted to neutralize and salify so as to construct ionomer type polyether polyol of a phosphate ester group and triethanolamine salt ion pair structure unit; the quality control of the hydroxyl value of 280-450 mgKOH / g, the acid value of 0.3-2.0 mgKOH / g, the water content of less than or equal to 0.05 wt% and the apparent viscosity of 3000-9000 mPa.s (25 DEG C, 10 s <-1 >) is realized; the problems of viscosity increase and insufficient fluidity caused by a high phosphate / ion pair polar structure, difficulty in consideration of a polyurethane processing window and flame-retardant efficiency improvement, and mechanism conflict between high-polarity crosslinking contribution and low-smoke low-corrosion and humid environment electrical property stability are solved; the material has balanced flame retardant property and comprehensive performance of processing and use, low water and low acid, and strict application value in quality control.

Description

Technical Field

[0001] This invention relates to the field of polyurethane raw material technology, specifically to a reactive flame-retardant polyether polyol and its preparation method. Background Technology

[0002] With the widespread application of polyurethane materials in building insulation, transportation, and electronics, flame retardant safety performance has become a core technical requirement for polyurethane foams, coatings, adhesives, and other products. Reactive flame-retardant polyether polyols are functional raw materials in which flame-retardant elements (phosphorus, nitrogen, halogens, etc.) are introduced into the molecular structure of polyether polyols through chemical bonding. Compared to additive flame retardants, they have advantages such as non-migration of flame-retardant elements, high flame-retardant efficiency, and good durability, thus attracting widespread attention in halogen-free flame-retardant polyurethane systems. Phosphorus-nitrogen synergistic flame-retardant technology is a recognized high-efficiency halogen-free flame-retardant route. Through the synergistic effect of phosphorus's condensed-phase char formation and nitrogen's gas-phase dilution / free radical capture, excellent flame-retardant performance can be achieved at low addition levels, while simultaneously reducing smoke density and corrosive gas release. To meet the stringent requirements of high flame retardancy ratings (such as UL94V-0, LOI > 28%) and low smoke and low toxicity (smoke density < 75, corrosive gases < 100 ppm), the structural design and synthesis process of reactive phosphorus-nitrogen flame-retardant polyether polyols have become a key direction for the development of polyurethane flame-retardant materials technology. Meanwhile, with the increasing demands from the electronics, electrical engineering, and rail transportation sectors for the mechanical properties (tensile strength > 20 MPa, compressive strength > 0.15 MPa) and long-term stability (electrical property retention > 90% in humid environments, salt spray test > 500 h) of polyurethane materials, reactive flame-retardant polyether polyols need to achieve a comprehensive balance between flame retardant performance, processing performance, and application performance.

[0003] Current research on reactive phosphorus-nitrogen flame-retardant polyether polyols mainly focuses on structural types such as phosphate ester, phosphonate, and phosphazene. These flame-retardant polyether polyols achieve their flame-retardant function by introducing phosphorus-nitrogen flame-retardant groups into the polyether backbone or side chain. However, existing technologies still have significant shortcomings in balancing high flame-retardant efficiency with overall performance. For example, Chinese patent application CN105199096A discloses the preparation and application of a nitrogen-phosphorus structured flame-retardant polyether polyol, which introduces phosphate ester groups into the polyether side chain through a phosphorylation reaction. However, this method suffers from problems such as the strong polarity of the phosphate ester groups leading to a significant increase in product viscosity (viscosity > 15000 mPa·s), insufficient flowability, poor compatibility with isocyanates, and a narrow processing window. For example, Chinese patent application CN112759753A discloses a method for preparing a phosphorus-nitrogen synergistic flame-retardant polyether polyol, using nitrogen- and phosphorus-containing compounds and polyols as composite initiators. However, this method suffers from limitations in flame-retardant efficiency due to nitrogen alone, requiring high addition amounts (>30wt%) to meet flame-retardant requirements, and increased NH3 release during combustion due to high nitrogen content. Furthermore, to improve the mechanical properties of flame-retardant polyether polyols, it is typically necessary to increase the content of polar groups such as phosphate esters and amino groups to enhance hydrogen bonding and crosslinking density. However, high polar group content significantly increases viscosity (viscosity >20000mPa·s), reduces flowability, and deteriorates processing performance. Simultaneously, in humid environments, polar groups readily absorb moisture, leading to decreased dimensional stability, deteriorated electrical properties, and increased corrosivity in polyurethane products. Therefore, how to balance the mechanistic conflicts between viscosity and flowability, processing window and metering mixing stability, and mechanical properties and long-term stability through molecular structure design while ensuring high flame-retardant efficiency, and thus achieve comprehensive performance optimization of reactive flame-retardant polyether polyols, is a pressing technical challenge. Summary of the Invention

[0004] The purpose of this invention is to provide a reactive flame-retardant polyether polyol and its preparation method, which solves the problems of viscosity increase and insufficient flowability caused by high phosphate ester / ion pair polar structure, difficulty in balancing polyurethane processing window and metering mixing stability with flame retardant efficiency improvement, and the mechanistic natural conflict between the high polarity and crosslinking contribution required to obtain high strength / high modulus and the long-term electrical performance stability in low smoke, low corrosion and humid environments.

[0005] As the core concept of this invention, it employs a synergistic approach of "co-initiated polymerization of phosphoramide diol and triethanolamine + phosphoesterification + construction of triethanolamine salt ion pairs" to solve the aforementioned technical challenges. Phosphoramide diol, as a bifunctional initiator, introduces PN bonds and phosphate ester groups as precursors. After co-initiating the ring-opening polymerization of propylene oxide with triethanolamine, it undergoes phosphorus pentoxide / phosphoesterification to form phosphate ester flame-retardant groups on the polyether side chains. Subsequently, residual phosphoric acid is neutralized with triethanolamine to form triethanolamine salt ion pair structural units. This ion pair structure forms a microscopic ionomer phase region through electrostatic attraction and hydrogen bonding, enhancing both the phosphorus-nitrogen synergistic flame-retardant efficiency (phosphorus element condenses into char + nitrogen element gas phase dilution) and viscosity regulation through ion aggregation (ion pairs aggregate through electrostatic attraction and hydrogen bonding to form a reversible physical cross-linked network, maintaining an appropriate viscosity level under static conditions; under processing shear conditions, partial dissociation of the ion pairs significantly reduces viscosity (shear thinning), thus achieving the desired flame retardant effect under the target testing conditions (25℃, 10 s). -1 The apparent viscosity is controlled at 3000–9000 mPa·s. At the same time, the dynamic reversibility of the ionomer phase region endows the system with excellent shear thinning behavior (viscosity decreases by >50% during processing), ensuring fluidity and processing window, and achieving a triple balance of flame retardant performance, processing performance and performance, reflecting synergistic effect.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A reactive flame-retardant polyether polyol, wherein the reactive flame-retardant polyether polyol is an ionomer type polyether polyol, comprising phosphate groups and triethanolamine salt ion-pair structural units formed by the phosphate groups and triethanolamine;

[0008] The reactive flame-retardant polyether polyol is obtained by reacting the following raw materials: triethanolamine; diethanolamine; diethyl chlorophosphate; triethylamine; propylene oxide; potassium hydroxide; phosphorus pentoxide; phosphoric acid; and nitrogen as a protective gas.

[0009] The reactive flame-retardant polyether polyols described herein have the following quality control indicators: hydroxyl value of 280-450 mgKOH / g; acid value of 0.3-2.0 mgKOH / g; and water content of not more than 0.05 wt%.

[0010] Furthermore, the preparation process of the reactive flame-retardant polyether polyol includes a step of preparing phosphoramide diol, which includes the following steps:

[0011] S1-A1: Raw material preparation: Diethanolamine and triethylamine are mixed under mechanical stirring conditions, with a molar ratio of diethanolamine to triethylamine of 1.00:1.00-1.05;

[0012] S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 0-10℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is controlled at 1:1.00-1.05, and the feeding time is 0.5-2.0h.

[0013] S1-A3: After the feeding is completed, raise the system temperature to 20-40℃ and keep it at that temperature for 1.0-4.0h.

[0014] S1-A4: Post-treatment: Filter to remove the solid salt produced in the reaction, and then devolatilize at 50-90℃ and a vacuum of 0.1-5kPa for 0.5-2.0h;

[0015] S1-A5: Endpoint Criteria and Quality Control: The chlorine content of the obtained phosphoramide diol is not higher than 0.10 wt%, and the phosphoramide diol is obtained.

[0016] Furthermore, the preparation process of the reactive flame-retardant polyether polyol includes a step of preparing an aminophosphoramide co-initiated polyoxypropylene polyol, the preparation of which includes the following steps:

[0017] S2-B1: Raw material preparation: Triethanolamine and phosphoramide diol are mixed in a mass ratio of 100-300:5-30, and potassium hydroxide is added, wherein the amount of potassium hydroxide is 0.05-0.20 wt% of the total mass of the triethanolamine and phosphoramide diol.

[0018] S2-B2: Dehydration: The system is heated to 90-115℃ under a nitrogen atmosphere, then evacuated to 0.1-3kPa and dehydrated for 0.5-2.0h;

[0019] S2-B3: Ring-opening polymerization: Control the system temperature at 95-125℃, add propylene oxide continuously under mechanical stirring, and maintain the system gauge pressure at 0.2-0.6MPa. Continue adding until the hydroxyl value of the obtained aminophosphamide co-initiated polyoxypropylene polyol is 280-450mgKOH / g; after the addition is completed, maintain the reaction temperature for 0.5-2.0h.

[0020] S2-B4: Deviation and neutralization: Deviation is carried out at 90-120℃ and vacuum degree of 0.1-3kPa for 0.5-2.0h, followed by neutralization with the addition of phosphoric acid. The amount of phosphoric acid added is based on the mass of H3PO4 therein, and the endpoint is determined by the acid value of the aminophosphamide co-initiated polyoxypropylene polyol being 0.0-0.5mgKOH / g.

[0021] S2-B5: Post-treatment: Filter to remove salt solids to obtain the aminophosphamide co-initiated polyoxypropylene polyol;

[0022] S2-B6: Quality Control: The aminophosphamide co-initiated polyoxypropylene polyol has a hydroxyl value of 280-450 mg KOH / g and a water content of no more than 0.05 wt%.

[0023] Furthermore, the preparation process of the reactive flame-retardant polyether polyol includes a step of preparing an acidic phosphoric acid esterified polyether polyol, the preparation of which includes the following steps:

[0024] S3-C1: Raw material preparation: Using aminophosphoramide co-initiated polyoxypropylene polyol as the reactant, phosphorus pentoxide and phosphoric acid are added, wherein the amount of phosphorus pentoxide is 0.5-5.0 wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid (calculated as H3PO4) is 0.2-3.0 wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol;

[0025] S3-C2: Phosphorylation: Under a nitrogen atmosphere, the system temperature is controlled at 50-90℃ and the reaction is carried out for 1.0-5.0 h;

[0026] S3-C3: Dehydration: Maintain the reaction temperature of step S3-C2 and dehydrate for 0.5-2.0 h under a vacuum of 0.1-3 kPa;

[0027] S3-C4: Endpoint Criteria and Quality Control: The reaction is stopped when the acid value of the acidic phosphoric acid esterified polyether polyol is 3.0-12.0 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol is obtained.

[0028] Furthermore, the hydroxyl functionality of the reactive flame-retardant polyether polyol is 2-6.

[0029] This invention employs a dual-initiator copolymerization of phosphoramide diol and triethanolamine, followed by controlled phosphoric acid esterification with phosphorus pentoxide / phosphoric acid, and then neutralization with triethanolamine to form a salt, constructing a reactive flame-retardant polyether polyol containing PN bonds, phosphate ester, and triethanolamine ion pairs. The pyrolysis of PN generates phosphorus-oxygen / nitrogen free radicals, achieving synergistic phosphorus-nitrogen effects by simultaneously achieving char formation in the condensed phase and capturing and diluting free radicals in the gas phase. In preferred embodiments, the LOI reaches 28–32%, UL94V-0, and smoke density <75. Triethanolamine modulates the functionality and PDI, forming an ionomer phase region, resulting in high storage viscosity and processing shear thinning, thus widening the storage window. Phosphate ester promotes metaphosphate glass film formation and dehydration to form char, improving toughness; neutralization lowers the acid value and enhances moisture resistance and long-term stability.

[0030] This invention also discloses a method for preparing reactive flame-retardant polyether polyols, comprising the following steps:

[0031] S1: Prepare phosphoramidide alcohol according to steps S1-A1 to S1-A5 as described in claim 2;

[0032] S2: Prepare aminophosphamide co-initiated polyoxypropylene polyols according to steps S2-B1 to S2-B6 of claim 3;

[0033] S3: Prepare acidic phosphoric acid esterified polyether polyols according to steps S3-C1 to S3-C4 of claim 4;

[0034] S4: Preparation of ionomer-type reactive flame-retardant polyether polyols;

[0035] Furthermore, the preparation of phosphoramide diol in step S1 includes the following sub-steps:

[0036] S1-A1: Diethanolamine and triethylamine are mixed under mechanical stirring conditions, with a molar ratio of diethanolamine to triethylamine of 1.00:1.00-1.05;

[0037] S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 0-10℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is 1:1.00-1.05, and the feeding time is 0.5-2.0h.

[0038] S1-A3: After the feeding is completed, raise the system temperature to 20-40℃ and keep it at that temperature for 1.0-4.0h.

[0039] S1-A4: Filter to remove the solid salt produced in the reaction, and then devolatilize at 50-90℃ and a vacuum of 0.1-5kPa for 0.5-2.0h;

[0040] S1-A5: The chlorine content of the obtained phosphoramidide diol is not higher than 0.10 wt%, thus obtaining phosphoramidide diol.

[0041] Furthermore, the preparation of the aminophosphamide co-initiated polyoxypropylene polyol in step S2 includes the following sub-steps:

[0042] S2-B1: Mix triethanolamine and phosphoramidol in a mass ratio of 100-300:5-30, and add potassium hydroxide in an amount of 0.05-0.20 wt% of the total mass of triethanolamine and phosphoramidol.

[0043] S2-B2: Heat the system to 90-115℃ under a nitrogen atmosphere, then evacuate to 0.1-3kPa and dehydrate for 0.5-2.0h;

[0044] S2-B3: Control the system temperature at 95-125℃, add propylene oxide continuously under mechanical stirring, and maintain the system gauge pressure at 0.2-0.6MPa. Continue adding until the hydroxyl value of the obtained aminophosphamide co-initiated polyoxypropylene polyol is 280-450mgKOH / g; after the addition is completed, keep the reaction at the temperature for 0.5-2.0h.

[0045] S2-B4: Deviation is carried out at 90-120℃ and vacuum degree of 0.1-3kPa for 0.5-2.0h, followed by neutralization with phosphoric acid. The amount of phosphoric acid added is based on the mass of H3PO4 therein, and the endpoint is determined by the acid value of the aminophosphamide co-initiated polyoxypropylene polyol being 0.0-0.5mgKOH / g.

[0046] S2-B5: Filter to remove salt solids to obtain aminophosphamide co-initiated polyoxypropylene polyol;

[0047] S2-B6: The hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol is 280-450 mg KOH / g and the water content is not higher than 0.05 wt%.

[0048] Furthermore, step S3 includes the following sub-steps:

[0049] S3-C1: Using aminophosphoramide co-initiated polyoxypropylene polyol as a reactant, phosphorus pentoxide and phosphoric acid are added. The amount of phosphorus pentoxide is 0.5-5.0 wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid (calculated as H3PO4) is 0.2-3.0 wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol.

[0050] S3-C2: Under a nitrogen atmosphere, the system temperature is controlled at 50-90℃ and the reaction is carried out for 1.0-5.0 h;

[0051] S3-C3: Maintain the reaction temperature of step S3-C2 and dehydrate for 0.5-2.0 h under a vacuum of 0.1-3 kPa;

[0052] S3-C4: The reaction is stopped when the acid value of the acidic phosphoric acid esterified polyether polyol is 3.0-12.0 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol is obtained.

[0053] Furthermore, step S4 includes the following sub-steps:

[0054] S4-D1: Raw material preparation: The acidic phosphoric acid esterified polyether polyol prepared in step S3 is used as a reactant, and triethanolamine is added. The amount of triethanolamine added is such that the acid value of the resulting ionomer-type reactive flame-retardant polyether polyol is 0.3-2.0 mgKOH / g.

[0055] S4-D2: Neutralization to form salt: Reaction at 30-70℃ for 0.5-3.0 h;

[0056] S4-D3: Endpoint Criterion and Quality Control: The reaction is stopped when the acid value of the ionomer-type reactive flame-retardant polyether polyol is 0.3-2.0 mg KOH / g, and triethanolamine salt ion-pair structural units are formed;

[0057] S4-D4: Post-treatment: Maintain the reaction temperature of step S4-D2, and devolve under a vacuum of 0.1-3 kPa for 0.5-2.0 h to ensure that the water content of the ionomer-type reactive flame-retardant polyether polyol is not higher than 0.05 wt%, thereby obtaining the reactive flame-retardant polyether polyol.

[0058] Furthermore, the reactive flame-retardant polyether polyol has a phosphorus content of 0.5-3.0 wt% and a nitrogen content of 0.2-1.5 wt%.

[0059] Furthermore, the mechanical stirring speed is 100-500 rpm, and the stirring method is paddle stirring or anchor stirring.

[0060] Furthermore, the feeding rate of propylene oxide is 0.5-10.0 g / min.

[0061] Furthermore, the phosphoric acid used in steps S2-B4 and S3-C1 is an aqueous solution of phosphoric acid with a mass fraction of 85 wt% H3PO4.

[0062] Furthermore, in step S2-B4, phosphoric acid is added dropwise at 40-80℃ for 0.2-1.5 hours.

[0063] Furthermore, the chlorine content was determined by argentometric titration (silver nitrate titration method), the acid value was determined according to GB / T12008.5-2010 "Plastics - Polyether Polyols - Part 5: Determination of Acid Value", the hydroxyl value was determined according to GB / T12008.3-2009 "Plastics - Polyether Polyols - Part 3: Determination of Hydroxyl Value", and the water content was determined according to GB / T22313-2008 "Plastics - Determination of Water Content of Polyols Used in Polyurethane Production" (Karl Fischer method).

[0064] Furthermore, the reactive flame-retardant polyether polyol has a phosphorus content of 0.5-3.0 wt% and a nitrogen content of 0.2-1.5 wt%.

[0065] Furthermore, the reactive flame-retardant polyether polyol is subjected to a shear rate of 10s at 25°C. -1The apparent viscosity measured under the conditions was 3000-9000 mPa·s. The testing instrument was a rotational rheometer, which adopted a cone-plate geometry with a cone angle of 2°, a cone plate diameter of 40 mm, and a gap of 50 μm. The sample was kept at constant temperature for 5 min, and the steady-state apparent viscosity was taken as the test result.

[0066] Furthermore, the degree of neutralization is calculated using the following formula: Degree of neutralization (%) = (1-AV4 / AV3)×100%, where AV3 is the acid value (mgKOH / g) of the acid phosphorylation esterified polyether polyol, and AV4 is the acid value (mgKOH / g) of the ionomer-type reactive flame-retardant polyether polyol.

[0067] Furthermore, in steps S1-A2, the dropping rate of diethyl chlorophosphate is 0.2-5.0 mL / min.

[0068] Furthermore, the dehydration endpoint criterion for steps S2-B2 and S3-C3 is a water content of less than 0.03 wt%.

[0069] Furthermore, the endpoint criterion for the devolatilization in step S4-D4 is that the residual triethanolamine content is less than 0.1 wt%, and the residual triethanolamine content is determined by gas chromatography.

[0070] Furthermore, the filtration in steps S1-A4 and S2-B5 uses filter membranes or filter cloths with a pore size of 0.1-10 μm.

[0071] Furthermore, the hydroxyl functionality of the reactive flame-retardant polyether polyol is calculated using the following formula: Hydroxyl functionality = Hydroxyl value × Mn / 56100, where the hydroxyl value is in mgKOH / g, Mn is the number-average molecular weight (g / mol), and Mn is determined by GPC. The GPC determination conditions are: the mobile phase is tetrahydrofuran, the flow rate is 1.0 mL / min, the column temperature is 40℃, and the calibration curve of polystyrene standard is used.

[0072] Furthermore, all steps are carried out under a nitrogen protective atmosphere with a nitrogen flow rate of 10-100 L / h; for steps requiring vacuuming, the corresponding operations are first performed under a nitrogen atmosphere, followed by vacuuming to the specified vacuum level and continuing the reaction or devolatilization.

[0073] Furthermore, the phosphoric acid used in step S3-C1 is an aqueous solution of phosphoric acid with a mass fraction of 85 wt% H3PO4.

[0074] Furthermore, in step S2-B4, phosphoric acid is added after the system has been devolatilized. The system temperature is lowered to 40-80℃, and then phosphoric acid is added dropwise over a period of 0.2-1.5 hours while stirring. Samples are taken periodically to determine the acid value, with an acid value of 0.0-0.5 mg KOH / g as the neutralization endpoint.

[0075] This invention proposes a four-step tandem process: S1 involves the phosphorylation (nucleophilic substitution) of diethanolamine with diethyl chlorophosphate to produce phosphoramide diol, with controlled temperature and molar ratio, and triethylamine used to capture the acid, resulting in a chlorine content <0.10wt% and a purity >98.5%; S2 involves the double-initiated ring-opening polymerization of propylene oxide with triethanolamine, with controlled KOH, dehydration, temperature, pressure, and feeding rate, ending at the hydroxyl value, followed by devolatilization and neutralization to remove K+. + The process yields a narrow-distribution intermediate; S3 involves P2O5 / phosphorylation, with controlled temperature, dosage, and vacuum dehydration, ending at acid value; S4 involves triethanolamine neutralization to form a salt, with controlled acid value, temperature, and volatilization to ensure ion pair formation. The entire process uses chlorine content, hydroxyl value, acid value, and water content as criteria to improve purity, batch consistency, and scale-up controllability.

[0076] The synergistic effect of phosphoramide diol and triethanolamine in the composite system is manifested at three levels: At the molecular structure level, the bifunctionality of phosphoramide diol and the trifunctionality of triethanolamine are precisely controlled by adjusting the mass ratio (100-300:5-30) to optimize the hydroxyl functionality (2-6) and molecular weight distribution (Mn 484-668 g / mol, PDI 1.05-1.20) of the polyether network, achieving synergistic optimization of branching degree and molecular weight; At the flame retardant mechanism level, the PN bond and phosphate ester group of phosphoramide diol provide condensed phase char formation and a glassy protective film, while the triethanolamine salt provides gas-phase NH3 dilution and free radical capture. The synergy between the condensed phase and the gas phase enhances the flame retardant effect. The efficiency improvement is >30%, superior to single-mechanism systems. In terms of viscosity regulation, the strong polarity (dipole moment >4.5D) of the phosphate ester groups introduced by phosphoramide diol would lead to uncontrolled viscosity (>25000 mPa·s) without the shielding regulation of triethanolamine salt ion pairs. Triethanolamine salt constructs a dynamic and reversible physical cross-linking network by forming an ionomer phase region. In static conditions, ion pair aggregation increases the storage modulus and controls viscosity (3000-9000 mPa·s), while in dynamic shear conditions, ion pair dissociation reduces viscosity (shear thinning >50%). This resolves the mechanistic contradiction between high polar group content and controllable viscosity, demonstrating the unique advantage of intelligent regulation in the ionomer phase region. In summary, phosphoramide diol and triethanolamine achieve a quadruple balance of flame retardant performance, mechanical properties, processing performance, and long-term stability through triple synergy of complementary molecular structures, synergistic flame retardant mechanisms, and intelligent viscosity regulation. Compared to single phosphoramide diol or single triethanolamine systems, the synergistic system shows an overall performance improvement of >50%.

[0077] Beneficial technical effects

[0078] 1. Phosphamide diol introduces P–N bonds and phosphate ester groups. During pyrolysis, phosphorus and oxygen free radicals promote dehydrogenation and cross-linking to form char, while nitrogen free radicals capture active free radicals and release N2 for dilution. Triethanolamine salt decomposes NH3 to further catalyze char formation and inhibit combustion, synergistically increasing LOI from 22–24% to 28–32%, UL94 from V-1 to V-0, smoke density from >100 to <75, and corrosive gases from >150ppm to <100ppm.

[0079] 2. Triethanolamine neutralizes to form ion pairs, which aggregate into ionomer phase regions through electrostatic and hydrogen bonding. This statically increases the modulus and stabilizes the viscosity at 3000–9000 mPa·s to ensure pumpability. Under high shear, the ion pairs partially dissociate, resulting in a viscosity decrease of >50%. The mixed viscosity is 1500–4500 mPa·s, and the processing window is widened by >40%. Even with high phosphorus content, it avoids the problems of traditional systems with viscosity >15000 mPa·s and poor thinning.

[0080] 3. The trifunctionality of triethanolamine increases the covalent crosslinking density, raising the tensile strength from 12–18 MPa to 20–28 MPa and the compressive strength from 0.10–0.12 MPa to 0.15–0.22 MPa; the strong polarity of phosphate esters improves the interface between hard and soft segments, increasing the elongation at break from 80–120% to 150–220%; ion pair shielding reduces water diffusion and controls the water content to <0.05wt%, with dimensional change <0.5% at 85%RH / 40℃ / 1000h and electrical properties maintained at >90%.

[0081] 4. Four-step tandem process: S1 intermediate chlorine <0.10wt%, purity >98.5%; S2 polymerization hydroxyl value controlled at 280–450±5, water content <0.05%; S3 phosphate esterification acid value controlled at 3–12±0.3, phosphorus 0.5–3.0; S4 neutralization acid value controlled at 0.3–2.0±0.1 and volatilization to reduce impurities, batch-to-batch variation <±3%, key parameter accuracy ±5%, scale-up and consistency improved by >50% compared to one-step / two-step methods.

[0082] 5. Establish a six-core indicator system: hydroxyl value, acid value, water content, apparent viscosity, phosphorus content, and nitrogen content. Hydroxyl value ensures reactivity, acid value constrains ion pair and coloring risks, water content suppresses monofunctional chains and size fluctuations, viscosity ensures measurement and processing, and phosphorus / nitrogen content balances flame retardancy and process. Combined with national standards and rheological testing, traceability and ±3% control accuracy are achieved, which is superior to traditional products that only control 2-3 items and have fluctuations >±10%. Attached Figure Description

[0083] Figure 1 The XPS P 2p high-resolution spectra of Example 1 and Comparative Example 7 are shown.

[0084] Figure 2 The XPS N 1s high-resolution spectra of Example 1 and Comparative Example 7 are shown.

[0085] Figure 3 The images show the FTIR spectra of Example 1 and Comparative Example 7.

[0086] Figure 4 This is the XPS P 2p peak fitting diagram for Example 1.

[0087] Figure 5 This is the XPS P 2p peak fitting plot for Comparative Example 5.

[0088] Figure 6 This is the XPS P 2p peak fitting plot for Comparative Example 8.

[0089] Figure 7 This is the XPS N 1s peak fitting diagram for Example 1.

[0090] Figure 8 This is the XPS N 1s peak fitting plot for Comparative Example 7.

[0091] Figure 9 Macroscopic photograph of the ionomer-type reactive flame-retardant polyether polyol prepared in Example 1.

[0092] Figure 10 This is a scanning electron microscope image of the reactive flame-retardant polyether polyol from Example 1. Detailed Implementation

[0093] 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.

[0094] Example 1

[0095] This embodiment provides a reactive flame-retardant polyether polyol. The reactive flame-retardant polyether polyol of this embodiment is an ionomer type polyether polyol, which contains phosphate groups and triethanolamine salt ion-pair structural units formed by the phosphate groups and triethanolamine of this embodiment.

[0096] The reactive flame-retardant polyether polyol of this embodiment is obtained by reacting the following raw materials: triethanolamine, diethanolamine, diethyl chlorophosphate, triethylamine, propylene oxide, potassium hydroxide, phosphorus pentoxide, phosphoric acid, and nitrogen as a protective gas.

[0097] The preparation method of the reactive flame-retardant polyether polyol in this embodiment includes the following steps:

[0098] S1: Preparation of phosphoramidino diol

[0099] S1-A1: Raw material preparation: Diethanolamine and triethylamine are mixed under mechanical stirring conditions. The molar ratio of diethanolamine to triethylamine is 1.00:1.02. The mechanical stirring speed is 300 rpm, and a paddle stirrer is used.

[0100] S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 5℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is 1:1.02, the addition time is 1.2h, and the dropping rate of diethyl chlorophosphate is 2.5mL / min.

[0101] S1-A3: After the feeding is completed, raise the system temperature to 30℃ and keep it at that temperature for 2.5h.

[0102] S1-A4: Post-treatment: Filter to remove the solid salt produced in the reaction using a 5μm pore size filter membrane, and devolve at 70℃ and 1.5kPa for 1.2h.

[0103] S1-A5: Endpoint Criteria and Quality Control: The chlorine content of the phosphoramidide diol obtained in this example is 0.05 wt%, determined by argentometric titration.

[0104] S2: Preparation of aminophosphoramide co-initiated polyoxypropylene polyol

[0105] S2-B1: Raw material preparation: Triethanolamine and phosphoramide diol are mixed in a mass ratio of 200:15, and potassium hydroxide is added. In this embodiment, the amount of potassium hydroxide used is 0.12 wt% of the total mass of triethanolamine and phosphoramide diol.

[0106] S2-B2: Dehydration: The system was heated to 102℃ under a nitrogen atmosphere, then evacuated to 1.5kPa and dehydrated for 1.2h. The endpoint of dehydration was determined by a water content of less than 0.03wt%. The water content was determined by the Karl Fischer method according to GB / T22313-2008.

[0107] S2-B3: Ring-opening polymerization: The system temperature was controlled at 110℃, and propylene oxide was added continuously under mechanical stirring at a rate of 5.0 g / min to maintain the system gauge pressure at 0.4 MPa. The addition continued until the hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol obtained in this example was 365 mg KOH / g. After the addition was completed, the reaction was kept at the temperature for 1.2 h.

[0108] S2-B4: Deviation and Neutralization: Deviation was carried out at 105℃ and 1.5kPa for 1.2h. Then, the system temperature was lowered to 60℃, and a phosphoric acid aqueous solution with a mass fraction of 85wt% H3PO4 was added for neutralization. The amount of phosphoric acid added was based on the mass of H3PO4 in it. The phosphoric acid was added dropwise over a period of 0.8h while stirring. The acid value was measured periodically. The neutralization endpoint was defined as an acid value of 0.2mgKOH / g for the aminophosphamide co-initiated polyoxypropylene polyol.

[0109] S2-B5: Post-treatment: Salt solids are removed by filtration using a 5μm pore size filter membrane to obtain the aminophosphamide co-initiated polyoxypropylene polyol of this embodiment.

[0110] S2-B6: Quality Control: The aminophosphamide co-initiated polyoxypropylene polyol in this embodiment has a hydroxyl value of 365 mg KOH / g and a water content of 0.02 wt%.

[0111] S3: Preparation of acidic phosphorylated polyether polyols

[0112] S3-C1: Raw material preparation: The above-mentioned aminophosphoramide co-initiated polyoxypropylene polyol is used as a reactant, and phosphoric acid aqueous solution with a mass fraction of 85wt% (phosphorus pentoxide and H3PO4) is added, wherein the amount of phosphorus pentoxide is 2.5wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid (calculated as H3PO4) is 1.5wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol.

[0113] S3-C2: Phosphorylation: Under a nitrogen atmosphere, the system temperature was controlled at 70℃ and the reaction was carried out for 3.0 h.

[0114] S3-C3: Dehydration: Maintain the reaction temperature of step S3-C2 and dehydrate for 1.2 h under a vacuum of 1.5 kPa. The endpoint of dehydration is defined as a water content of less than 0.03 wt%.

[0115] S3-C4: Endpoint Criteria and Quality Control: The reaction was stopped when the acid value of the acidic phosphoric acid esterified polyether polyol was 7.0 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol of this embodiment was obtained.

[0116] S4: Preparation of ionomer-type reactive flame-retardant polyether polyols;

[0117] S4-D1: Raw material preparation: The acidic phosphoric acid esterified polyether polyol prepared in step S3 is used as a reactant, and triethanolamine is added. In this embodiment, the amount of triethanolamine added is based on the acid value of the ionomer-type reactive flame-retardant polyether polyol obtained in this embodiment being 1.0 mg KOH / g.

[0118] S4-D2: Neutralization to form salt: Reaction at 50℃ for 1.5h.

[0119] S4-D3: Endpoint Criterion and Quality Control: The reaction is stopped when the acid value of the ionomer-type reactive flame-retardant polyether polyol is 1.0 mg KOH / g, and triethanolamine salt ion-pair structural units are formed. The degree of neutralization is calculated according to the following formula: Degree of neutralization = (1-AV4 / AV3)×100%, where AV3 is the acid value of the acidic phosphoric acid esterified polyether polyol (7.0 mg KOH / g) and AV4 is the acid value of the ionomer-type reactive flame-retardant polyether polyol (1.0 mg KOH / g). The calculated degree of neutralization is 85.7%.

[0120] S4-D4: Post-treatment: Maintain the reaction temperature of step S4-D2, and devolve under a vacuum of 1.5 kPa for 1.2 h to make the water content of the ionomer-type reactive flame-retardant polyether polyol 0.03 wt% and the residual triethanolamine content less than 0.1 wt%. The residual triethanolamine content was determined by gas chromatography to obtain the reactive flame-retardant polyether polyol of this embodiment.

[0121] Quality control indicators

[0122] The reactive flame-retardant polyether polyol of this embodiment has the following quality control indicators:

[0123] The hydroxyl value was 365 mg KOH / g, determined according to GB / T12008.3-2009;

[0124] The acid value is 1.0 mg KOH / g, determined according to GB / T12008.5-2010;

[0125] The moisture content was 0.03 wt%, determined by the Karl Fischer method according to GB / T22313-2008;

[0126] The phosphorus content is 1.5 wt%;

[0127] The nitrogen content is 0.8 wt%;

[0128] The hydroxyl functionality is 4, calculated using the following formula: Hydroxyl functionality = hydroxyl value × Mn / 56100, where Mn is 615 g / mol. It is determined by GPC method. The GPC determination conditions are: mobile phase is tetrahydrofuran, flow rate is 1.0 mL / min, column temperature is 40℃, and the calibration curve of polystyrene standard is used.

[0129] The apparent viscosity is 6000 mPa·s, and the viscosity at 25℃ and a shear rate of 10 s⁻¹ is... -1 The results were obtained under the following conditions. The testing instrument was a rotational rheometer, which adopted a cone-plate geometry with a cone angle of 2°, a cone plate diameter of 40 mm, a gap of 50 μm, and a sample isothermal equilibrium time of 5 min. The steady-state apparent viscosity was taken as the test result.

[0130] Nitrogen protection at all stages

[0131] All steps are carried out under a nitrogen protective atmosphere with a nitrogen flow rate of 50 L / h. For steps requiring vacuuming, the corresponding operation is first performed under a nitrogen atmosphere, followed by vacuuming to the specified vacuum level and continuing the reaction or devolatilization.

[0132] Features of the Implementation Examples

[0133] This embodiment employs a moderate parameter configuration scheme, with a triethanolamine to phosphoramide diol mass ratio of 200:15, a hydroxyl value of 365 mg KOH / g, a phosphorus content of 1.5 wt%, a nitrogen content of 0.8 wt%, a hydroxyl functionality of 4, and an apparent viscosity of 6000 mPa·s. The selection of each process parameter within a suitable range ensures the stability of the production process and the balance of product performance. The ratio of phosphoramide diol to triethanolamine achieves a good balance between flame retardant properties and reactivity. The polymerization temperature of 110℃ and the gauge pressure of 0.4 MPa ensure the appropriate progress of the ring-opening polymerization of propylene oxide. The phosphorylation reaction at 70℃ for 3.0 h achieves sufficient functionalization modification. The neutralization temperature of 50℃ and the reaction time of 1.5 h ensure the effective formation of ion-pair structures. The overall scheme exhibits excellent process stability and controllable product quality. This embodiment is applicable to the preparation of flame-retardant polyurethane foam materials with excellent comprehensive performance, and is particularly suitable for applications such as building insulation materials, furniture soft filling materials, and automotive interior materials, which require a balance of flame retardancy, mechanical strength, and processing performance.

[0134] Example 2

[0135] This embodiment provides a reactive flame-retardant polyether polyol. The reactive flame-retardant polyether polyol of this embodiment is an ionomer type polyether polyol, which contains phosphate groups and triethanolamine salt ion-pair structural units formed by the phosphate groups and triethanolamine of this embodiment.

[0136] The reactive flame-retardant polyether polyol of this embodiment is obtained by reacting the following raw materials: triethanolamine, diethanolamine, diethyl chlorophosphate, triethylamine, propylene oxide, potassium hydroxide, phosphorus pentoxide, phosphoric acid, and nitrogen as a protective gas.

[0137] The preparation method of the reactive flame-retardant polyether polyol in this embodiment includes the following steps:

[0138] S1: Preparation of phosphoramidino diol

[0139] S1-A1: Raw material preparation: Diethanolamine and triethylamine are mixed under mechanical stirring conditions. The molar ratio of diethanolamine to triethylamine is 1.00:1.04. The mechanical stirring speed is 350 rpm, and anchor stirring is used.

[0140] S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 3℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is 1:1.04, the feeding time is 1.5h, and the dropping rate of diethyl chlorophosphate is 1.5mL / min.

[0141] S1-A3: After the feeding is completed, raise the system temperature to 25℃ and keep it at that temperature for 3.0h.

[0142] S1-A4: Post-treatment: Filter to remove the solid salt produced in the reaction using a 3μm pore size filter membrane, and devolve at 80℃ and 0.5kPa for 1.5h.

[0143] S1-A5: Endpoint Criteria and Quality Control: The chlorine content of the phosphoramidide diol obtained in this example was 0.03 wt%, determined by argentometric titration.

[0144] S2: Preparation of aminophosphoramide co-initiated polyoxypropylene polyol

[0145] S2-B1: Raw material preparation: Triethanolamine and phosphoramide diol are mixed in a mass ratio of 150:20, and potassium hydroxide is added. In this embodiment, the amount of potassium hydroxide used is 0.15 wt% of the total mass of triethanolamine and phosphoramide diol.

[0146] S2-B2: Dehydration: The system was heated to 108°C under a nitrogen atmosphere, then evacuated to 0.8 kPa and dehydrated for 1.5 h. The endpoint of dehydration was determined by a water content of less than 0.03 wt%. The water content was determined by the Karl Fischer method according to GB / T22313-2008.

[0147] S2-B3: Ring-opening polymerization: The system temperature was controlled at 105℃, and propylene oxide was added continuously under mechanical stirring at a rate of 3.0 g / min to maintain the system gauge pressure at 0.5 MPa. The addition continued until the hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol obtained in this example was 300 mg KOH / g. After the addition was completed, the reaction was kept at the temperature for 1.5 h.

[0148] S2-B4: Deviation and Neutralization: Deviation was carried out at 110℃ and 0.8kPa for 1.5h. Then, the system temperature was lowered to 70℃, and a phosphoric acid aqueous solution with a mass fraction of 85wt% H3PO4 was added for neutralization. The amount of phosphoric acid added was based on the mass of H3PO4 in it. The phosphoric acid was added dropwise over 1.0h, with stirring during addition. The acid value was measured periodically, and the neutralization endpoint was defined as an acid value of 0.3mgKOH / g for the aminophosphamide co-initiated polyoxypropylene polyol.

[0149] S2-B5: Post-treatment: Salt solids are removed by filtration using a 3μm pore size filter membrane to obtain the aminophosphamide co-initiated polyoxypropylene polyol of this embodiment.

[0150] S2-B6: Quality Control: In this embodiment, the aminophosphamide co-initiated polyoxypropylene polyol has a hydroxyl value of 300 mg KOH / g and a water content of 0.02 wt%.

[0151] S3: Preparation of acidic phosphorylated polyether polyols

[0152] S3-C1: Raw material preparation: The above-mentioned aminophosphoramide co-initiated polyoxypropylene polyol is used as a reactant, and phosphoric acid aqueous solution with a mass fraction of 85wt% of phosphorus pentoxide and H3PO4 is added, wherein the amount of phosphorus pentoxide is 4.0wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid, calculated as H3PO4, is 2.5wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol.

[0153] S3-C2: Phosphorylation: Under a nitrogen atmosphere, the system temperature was controlled at 80℃ and the reaction was carried out for 4.0 h.

[0154] S3-C3: Dehydration: Maintain the reaction temperature of step S3-C2 and dehydrate for 1.5 h under a vacuum of 0.8 kPa. The endpoint of dehydration is defined as a water content of less than 0.03 wt%.

[0155] S3-C4: Endpoint Criteria and Quality Control: The reaction was stopped when the acid value of the acidic phosphoric acid esterified polyether polyol was 10.0 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol of this embodiment was obtained.

[0156] S4: Preparation of ionomer-type reactive flame-retardant polyether polyols;

[0157] S4-D1: Raw material preparation: The acidic phosphoric acid esterified polyether polyol prepared in step S3 is used as a reactant, and triethanolamine is added. In this embodiment, the amount of triethanolamine added is based on the acid value of the ionomer-type reactive flame-retardant polyether polyol obtained in this embodiment being 0.5 mg KOH / g.

[0158] S4-D2: Neutralization to salt formation: Reaction at 60℃ for 2.0 h.

[0159] S4-D3: Endpoint Criterion and Quality Control: The reaction is stopped when the acid value of the ionomer-type reactive flame-retardant polyether polyol is 0.5 mg KOH / g, and triethanolamine salt ion-pair structural units are formed. The degree of neutralization is calculated according to the following formula: Degree of neutralization = (1-AV4 / AV3)×100%, where AV3 is the acid value of the acidic phosphoric acid esterified polyether polyol (10.0 mg KOH / g) and AV4 is the acid value of the ionomer-type reactive flame-retardant polyether polyol (0.5 mg KOH / g). The calculated degree of neutralization is 95.0%.

[0160] S4-D4: Post-treatment: Maintain the reaction temperature of step S4-D2, and devolve under a vacuum of 0.8 kPa for 1.5 h to make the water content of the ionomer-type reactive flame-retardant polyether polyol 0.02 wt% and the residual triethanolamine content less than 0.1 wt%. The residual triethanolamine content was determined by gas chromatography to obtain the reactive flame-retardant polyether polyol of this embodiment.

[0161] Quality control indicators

[0162] The reactive flame-retardant polyether polyol of this embodiment has the following quality control indicators;

[0163] The hydroxyl value was 300 mg KOH / g, determined according to GB / T12008.3-2009;

[0164] The acid value is 0.5 mg KOH / g, determined according to GB / T12008.5-2010;

[0165] The moisture content was 0.02 wt%, determined by the Karl Fischer method according to GB / T22313-2008;

[0166] The phosphorus content is 2.5 wt%;

[0167] The nitrogen content is 1.2 wt%;

[0168] The hydroxyl functionality is 3, calculated using the following formula: Hydroxyl functionality = hydroxyl value × Mn / 56100, where Mn is 561 g / mol. It is determined by GPC method. The GPC determination conditions are: mobile phase is tetrahydrofuran, flow rate is 1.0 mL / min, column temperature is 40℃, and the calibration curve of polystyrene standard is used.

[0169] The apparent viscosity is 7500 mPa·s, and the viscosity at 25℃ and a shear rate of 10 s⁻¹ is [missing value]. -1 The results were obtained under the following conditions. The testing instrument was a rotational rheometer, which adopted a cone-plate geometry with a cone angle of 2°, a cone plate diameter of 40 mm, a gap of 50 μm, and a sample isothermal equilibrium time of 5 min. The steady-state apparent viscosity was taken as the test result.

[0170] Nitrogen protection at all stages

[0171] All steps are carried out under a nitrogen protective atmosphere with a nitrogen flow rate of 60 L / h. For steps requiring vacuuming, the corresponding operation is first performed under a nitrogen atmosphere, followed by vacuuming to the specified vacuum level and continuing the reaction or devolatilization.

[0172] Features of the Implementation Examples

[0173] This embodiment employs a high-phosphorus content formulation with a triethanolamine to phosphoramide diol mass ratio of 150:20, a hydroxyl value of 300 mg KOH / g, a phosphorus content of 2.5 wt%, a nitrogen content of 1.2 wt%, a hydroxyl functionality of 3, and an apparent viscosity of 7500 mPa·s. The high phosphorus content of the product is achieved by increasing the proportion of phosphoramide diol in the initiator and increasing the amount of phosphorus pentoxide. The lower hydroxyl value results in a higher molecular weight. A polymerization temperature of 105℃ combined with a gauge pressure of 0.5 MPa ensures an appropriate molecular chain length. The phosphorylation reaction is carried out at 80℃ for 4.0 h using 4.0 wt% phosphorus pentoxide to achieve sufficient functionalization. A neutralization temperature of 60℃, a reaction time of 2.0 h, and a high degree of neutralization of 95.0% ensure the formation of a large number of ion-pair structures. The overall scheme significantly improves the flame retardant performance of the product. This embodiment is applicable to the preparation of polyurethane materials with high flame retardancy rating, and is particularly suitable for applications with strict requirements for flame retardancy performance, such as electronic and electrical appliance housing materials, public transportation vehicle interior materials, and high-rise building fireproof and thermal insulation materials, which require excellent flame retardancy performance.

[0174] Example 3

[0175] This embodiment provides a reactive flame-retardant polyether polyol. The reactive flame-retardant polyether polyol of this embodiment is an ionomer type polyether polyol, which contains phosphate groups and triethanolamine salt ion-pair structural units formed by the phosphate groups and triethanolamine of this embodiment.

[0176] The reactive flame-retardant polyether polyol of this embodiment is obtained by reacting the following raw materials: triethanolamine, diethanolamine, diethyl chlorophosphate, triethylamine, propylene oxide, potassium hydroxide, phosphorus pentoxide, phosphoric acid, and nitrogen as a protective gas.

[0177] The preparation method of the reactive flame-retardant polyether polyol in this embodiment includes the following steps:

[0178] S1: Preparation of phosphoramidino diol

[0179] S1-A1: Raw material preparation: Diethanolamine and triethylamine are mixed under mechanical stirring conditions. The molar ratio of diethanolamine to triethylamine is 1.00:1.01. The mechanical stirring speed is 250 rpm, and a paddle stirrer is used.

[0180] S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 7℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is 1:1.01, the addition time is 0.8h, and the dropping rate of diethyl chlorophosphate is 3.5mL / min.

[0181] S1-A3: After the feeding is completed, raise the system temperature to 35℃ and keep it at that temperature for 1.5h.

[0182] S1-A4: Post-treatment: The solid salt produced by the reaction is removed by filtration using a 7μm pore size filter membrane, and the salt is de-devoured at 60℃ and 2.5kPa for 0.8h.

[0183] S1-A5: Endpoint Criteria and Quality Control: The chlorine content of the phosphoramidide diol obtained in this example was 0.07 wt%, determined by argentometric titration.

[0184] S2: Preparation of aminophosphoramide co-initiated polyoxypropylene polyol

[0185] S2-B1: Raw material preparation: Triethanolamine and phosphoramide diol are mixed in a mass ratio of 250:10, and potassium hydroxide is added. In this embodiment, the amount of potassium hydroxide used is 0.08 wt% of the total mass of triethanolamine and phosphoramide diol.

[0186] S2-B2: Dehydration: The system was heated to 96°C under a nitrogen atmosphere, then evacuated to 2.0 kPa and dehydrated for 0.8 h. The endpoint of dehydration was determined by a water content of less than 0.03 wt%. The water content was determined by the Karl Fischer method according to GB / T22313-2008.

[0187] S2-B3: Ring-opening polymerization: The system temperature was controlled at 115℃, and propylene oxide was added continuously under mechanical stirring at a rate of 7.0 g / min to maintain the system gauge pressure at 0.3 MPa. The addition continued until the hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol obtained in this example was 420 mg KOH / g. After the addition was completed, the reaction was kept at the temperature for 0.8 h.

[0188] S2-B4: Deviation and Neutralization: Deviation was carried out at 100℃ and 2.0kPa for 0.8h. Then, the system temperature was lowered to 50℃, and a phosphoric acid aqueous solution with a mass fraction of 85wt% H3PO4 was added for neutralization. The amount of phosphoric acid added was based on the mass of H3PO4 in it. The phosphoric acid was added dropwise over a period of 0.5h while stirring. The acid value was measured periodically. The neutralization endpoint was defined as an acid value of 0.1mgKOH / g for the aminophosphamide co-initiated polyoxypropylene polyol.

[0189] S2-B5: Post-treatment: Salt solids are removed by filtration using a 7μm pore size filter membrane to obtain the aminophosphamide co-initiated polyoxypropylene polyol of this embodiment.

[0190] S2-B6: Quality Control: The aminophosphamide co-initiated polyoxypropylene polyol in this embodiment has a hydroxyl value of 420 mg KOH / g and a water content of 0.02 wt%.

[0191] S3: Preparation of acidic phosphorylated polyether polyols

[0192] S3-C1: Raw material preparation: The above-mentioned aminophosphoramide co-initiated polyoxypropylene polyol is used as a reactant, and phosphoric acid aqueous solution with a mass fraction of 85wt% of phosphorus pentoxide and H3PO4 is added, wherein the amount of phosphorus pentoxide is 1.5wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid, calculated as H3PO4, is 0.8wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol.

[0193] S3-C2: Phosphorylation: Under a nitrogen atmosphere, the system temperature was controlled at 60℃ and the reaction was carried out for 2.0 h.

[0194] S3-C3: Dehydration: Maintain the reaction temperature of step S3-C2 and dehydrate for 0.8 h under a vacuum of 2.0 kPa. The endpoint of dehydration is defined as a water content of less than 0.03 wt%.

[0195] S3-C4: Endpoint Criteria and Quality Control: The reaction was stopped when the acid value of the acidic phosphoric acid esterified polyether polyol was 5.0 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol of this embodiment was obtained.

[0196] S4: Preparation of ionomer-type reactive flame-retardant polyether polyols;

[0197] S4-D1: Raw material preparation: The acidic phosphoric acid esterified polyether polyol prepared in step S3 is used as a reactant, and triethanolamine is added. In this embodiment, the amount of triethanolamine added is based on the acid value of the ionomer-type reactive flame-retardant polyether polyol obtained in this embodiment being 1.5 mg KOH / g.

[0198] S4-D2: Neutralization to salt formation: Reaction at 40℃ for 1.0 h.

[0199] S4-D3: Endpoint Criterion and Quality Control: The reaction is stopped when the acid value of the ionomer-type reactive flame-retardant polyether polyol is 1.5 mg KOH / g, and triethanolamine salt ion-pair structural units are formed. The degree of neutralization is calculated according to the following formula: Degree of neutralization = (1-AV4 / AV3)×100%, where AV3 is the acid value of the acidic phosphoric acid esterified polyether polyol (5.0 mg KOH / g) and AV4 is the acid value of the ionomer-type reactive flame-retardant polyether polyol (1.5 mg KOH / g). The calculated degree of neutralization is 70.0%.

[0200] S4-D4: Post-treatment: Maintain the reaction temperature of step S4-D2, and devolve under a vacuum of 2.0 kPa for 0.8 h to make the water content of the ionomer-type reactive flame-retardant polyether polyol 0.04 wt% and the residual triethanolamine content less than 0.1 wt%. The residual triethanolamine content was determined by gas chromatography to obtain the reactive flame-retardant polyether polyol of this embodiment.

[0201] Quality control indicators

[0202] The reactive flame-retardant polyether polyol of this embodiment has the following quality control indicators:

[0203] The hydroxyl value was 420 mg KOH / g, determined according to GB / T12008.3-2009;

[0204] The acid value is 1.5 mg KOH / g, determined according to GB / T12008.5-2010;

[0205] The moisture content was 0.04 wt%, determined by the Karl Fischer method according to GB / T22313-2008;

[0206] The phosphorus content is 1.0 wt%;

[0207] The nitrogen content is 0.5 wt%;

[0208] The hydroxyl functionality is 5, calculated using the following formula: Hydroxyl functionality = hydroxyl value × Mn / 56100, where Mn is 668 g / mol. It is determined by GPC method. The GPC determination conditions are: mobile phase is tetrahydrofuran, flow rate is 1.0 mL / min, column temperature is 40℃, and the calibration curve of polystyrene standard is used.

[0209] The apparent viscosity is 4500 mPa·s, and the viscosity at 25℃ and a shear rate of 10 s⁻¹ is [missing value]. -1 The results were obtained under the following conditions. The testing instrument was a rotational rheometer, which adopted a cone-plate geometry with a cone angle of 2°, a cone plate diameter of 40 mm, a gap of 50 μm, and a sample isothermal equilibrium time of 5 min. The steady-state apparent viscosity was taken as the test result.

[0210] Nitrogen protection at all stages

[0211] All steps are carried out under a nitrogen protective atmosphere with a nitrogen flow rate of 40 L / h. For steps requiring vacuuming, the corresponding operation is first performed under a nitrogen atmosphere, followed by vacuuming to the specified vacuum level and continuing the reaction or devolatilization.

[0212] Features of the Implementation Examples

[0213] This embodiment employs a high hydroxyl value formulation with a triethanolamine to phosphoramide diol mass ratio of 250:10, a hydroxyl value of 420 mg KOH / g, a phosphorus content of 1.0 wt%, a nitrogen content of 0.5 wt%, a hydroxyl functionality of 5, and an apparent viscosity of 4500 mPa·s. Lower phosphorus and nitrogen content is achieved by reducing the proportion of phosphoramide diol in the initiator. The higher hydroxyl value results in a lower molecular weight and higher reactivity. A polymerization temperature of 115℃ combined with a gauge pressure of 0.3 MPa facilitates the formation of smaller molecular weight polyether segments. The phosphorylation reaction is carried out at 60℃ for 2.0 h, and moderate functionalization modification is achieved using 1.5 wt% phosphorus pentoxide. A neutralization temperature of 40℃, a reaction time of 1.0 h, and a neutralization degree of 70.0% ensure the formation of appropriate ion-pair structures. The lower apparent viscosity is beneficial for subsequent processing. Overall, this scheme significantly improves the product's reactivity and processing performance. This embodiment is applicable to the preparation of fast-curing polyurethane materials, and is particularly suitable for applications requiring high reaction speed, such as polyurethane sprayed foam insulation materials, polyurethane potting materials, and polyurethane rapid prototyping products, which require high reactivity and good flowability.

[0214] Example 4

[0215] This embodiment provides a reactive flame-retardant polyether polyol. The reactive flame-retardant polyether polyol of this embodiment is an ionomer type polyether polyol, which contains phosphate groups and triethanolamine salt ion-pair structural units formed by the phosphate groups and triethanolamine of this embodiment.

[0216] The reactive flame-retardant polyether polyol of this embodiment is obtained by reacting the following raw materials: triethanolamine, diethanolamine, diethyl chlorophosphate, triethylamine, propylene oxide, potassium hydroxide, phosphorus pentoxide, phosphoric acid, and nitrogen as a protective gas.

[0217] The preparation method of the reactive flame-retardant polyether polyol in this embodiment includes the following steps:

[0218] S1: Preparation of phosphoramidino diol

[0219] S1-A1: Raw material preparation: Diethanolamine and triethylamine are mixed under mechanical stirring conditions. The molar ratio of diethanolamine to triethylamine is 1.00:1.00. The mechanical stirring speed is 450 rpm, and anchor stirring is used.

[0220] S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 9℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is 1:1.05, the feeding time is 0.6h, and the dropping rate of diethyl chlorophosphate is 4.5mL / min.

[0221] S1-A3: After the feeding is completed, raise the system temperature to 38℃ and keep it at that temperature for 3.5h.

[0222] S1-A4: Post-treatment: The solid salt produced by the reaction was removed by filtration using a 9μm pore size filter membrane, and the salt was de-devoured at 85℃ and 0.2kPa for 1.8h.

[0223] S1-A5: Endpoint Criteria and Quality Control: The chlorine content of the phosphoramidide diol obtained in this example was 0.04 wt%, determined by argentometric titration.

[0224] S2: Preparation of aminophosphoramide co-initiated polyoxypropylene polyol

[0225] S2-B1: Raw material preparation: Triethanolamine and phosphoramide diol are mixed in a mass ratio of 110:28, and potassium hydroxide is added. In this embodiment, the amount of potassium hydroxide is 0.18 wt% of the total mass of triethanolamine and phosphoramide diol.

[0226] S2-B2: Dehydration: The system was heated to 113°C under a nitrogen atmosphere, then evacuated to 0.2 kPa and dehydrated for 1.8 h. The endpoint of dehydration was determined by a water content of less than 0.03 wt%. The water content was determined by the Karl Fischer method according to GB / T22313-2008.

[0227] S2-B3: Ring-opening polymerization: The system temperature was controlled at 122℃, and propylene oxide was added continuously under mechanical stirring at a rate of 9.0 g / min to maintain the system gauge pressure at 0.55 MPa. The addition continued until the hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol obtained in this example was 290 mg KOH / g. After the addition was completed, the reaction was kept at the temperature for 1.8 h.

[0228] S2-B4: Deviation and Neutralization: Deviation was carried out at 118℃ and 0.2kPa for 1.8h. Then, the system temperature was lowered to 75℃, and a phosphoric acid aqueous solution with a mass fraction of 85wt% H3PO4 was added for neutralization. The amount of phosphoric acid added was based on the mass of H3PO4 in it. The phosphoric acid was added dropwise over a period of 0.3h while stirring. The acid value was measured periodically. The neutralization endpoint was defined as an acid value of 0.45mgKOH / g for the aminophosphamide co-initiated polyoxypropylene polyol.

[0229] S2-B5: Post-processing: Salt solids are removed by filtration using a 9μm pore size filter membrane to obtain the aminophosphamide co-initiated polyoxypropylene polyol of this embodiment.

[0230] S2-B6: Quality Control: The aminophosphamide co-initiated polyoxypropylene polyol in this embodiment has a hydroxyl value of 290 mg KOH / g and a water content of 0.02 wt%.

[0231] S3: Preparation of acidic phosphorylated polyether polyols

[0232] S3-C1: Raw material preparation: The above-mentioned aminophosphoramide co-initiated polyoxypropylene polyol is used as a reactant, and phosphoric acid aqueous solution with a mass fraction of 85wt% (phosphorus pentoxide and H3PO4) is added, wherein the amount of phosphorus pentoxide is 0.6wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid (calculated as H3PO4) is 0.3wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol.

[0233] S3-C2: Phosphorylation: Under a nitrogen atmosphere, the system temperature was controlled at 55℃ and the reaction was carried out for 4.5 h.

[0234] S3-C3: Dehydration: Maintain the reaction temperature of step S3-C2 and dehydrate for 1.8 h under a vacuum of 0.2 kPa. The endpoint of dehydration is defined as a water content of less than 0.03 wt%.

[0235] S3-C4: Endpoint Criteria and Quality Control: The reaction was stopped when the acid value of the acidic phosphoric acid esterified polyether polyol was 3.5 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol of this embodiment was obtained.

[0236] S4: Preparation of ionomer-type reactive flame-retardant polyether polyols;

[0237] S4-D1: Raw material preparation: The acidic phosphoric acid esterified polyether polyol prepared in step S3 is used as a reactant, and triethanolamine is added. In this embodiment, the amount of triethanolamine added is based on the acid value of the ionomer-type reactive flame-retardant polyether polyol obtained in this embodiment being 1.8 mgKOH / g.

[0238] S4-D2: Neutralization to form salt: Reaction at 35℃ for 2.5h.

[0239] S4-D3: Endpoint Criterion and Quality Control: The reaction is stopped when the acid value of the ionomer-type reactive flame-retardant polyether polyol is 1.8 mg KOH / g, and triethanolamine salt ion-pair structural units are formed. The degree of neutralization is calculated according to the following formula: Degree of neutralization = (1-AV4 / AV3)×100%, where AV3 is the acid value of the acidic phosphoric acid esterified polyether polyol (3.5 mg KOH / g) and AV4 is the acid value of the ionomer-type reactive flame-retardant polyether polyol (1.8 mg KOH / g). The calculated degree of neutralization is 48.6%.

[0240] S4-D4: Post-treatment: Maintain the reaction temperature of step S4-D2, and devolve for 1.8 h under a vacuum of 0.2 kPa to make the water content of the ionomer-type reactive flame-retardant polyether polyol 0.04 wt% and the residual triethanolamine content less than 0.1 wt%. The residual triethanolamine content was determined by gas chromatography to obtain the reactive flame-retardant polyether polyol of this embodiment.

[0241] Quality control indicators

[0242] The reactive flame-retardant polyether polyol of this embodiment has the following quality control indicators:

[0243] The hydroxyl value was 290 mg KOH / g, determined according to GB / T12008.3-2009;

[0244] The acid value was 1.8 mg KOH / g, determined according to GB / T12008.5-2010;

[0245] The moisture content was 0.04 wt%, determined by the Karl Fischer method according to GB / T22313-2008;

[0246] The phosphorus content is 0.6 wt%;

[0247] The nitrogen content is 0.3 wt%;

[0248] The hydroxyl functionality is 2.5, calculated using the following formula: Hydroxyl functionality = hydroxyl value × Mn / 56100, where Mn is 484 g / mol. It is determined by GPC method. The GPC determination conditions are: mobile phase is tetrahydrofuran, flow rate is 1.0 mL / min, column temperature is 40℃, and the calibration curve of polystyrene standard is used.

[0249] The apparent viscosity is 8500 mPa·s, and the viscosity at 25℃ and a shear rate of 10 s⁻¹ is [missing value]. -1 The results were obtained under the following conditions. The testing instrument was a rotational rheometer, which adopted a cone-plate geometry with a cone angle of 2°, a cone plate diameter of 40 mm, a gap of 50 μm, and a sample isothermal equilibrium time of 5 min. The steady-state apparent viscosity was taken as the test result.

[0250] Nitrogen protection at all stages

[0251] All steps are carried out under a nitrogen protective atmosphere with a nitrogen flow rate of 90 L / h. For steps requiring vacuuming, the corresponding operation is first performed under a nitrogen atmosphere, followed by vacuuming to the specified vacuum level and continuing the reaction or devolatilization.

[0252] Features of the Implementation Examples

[0253] This embodiment employs a parameter range-end configuration scheme, with a triethanolamine to phosphoramidide mass ratio of 110:28, a hydroxyl value of 290 mg KOH / g, a phosphorus content of 0.6 wt%, a nitrogen content of 0.3 wt%, a hydroxyl functionality of 2.5, and an apparent viscosity of 8500 mPa·s. A unique product structure is achieved through a high proportion of phosphoramidide but a low amount of phosphorylation reagent. The molar ratio of diethanolamine to triethylamine of 1.00:1.00 ensures precise control of the phosphoramidide structure, and the low hydroxyl value results in… The high molecular weight and low hydroxyl functionality, combined with a polymerization temperature of 122℃ and a gauge pressure of 0.55MPa, facilitated the formation of long-chain polyether structures. Phosphorylation at 55℃ for 4.5 hours, using 0.6wt% phosphorus pentoxide, achieved appropriate functionalization. A neutralization temperature of 35℃, a reaction time of 2.5 hours, and a neutralization degree of 48.6% ensured the formation of appropriate ion-pair structures. The high apparent viscosity and molecular weight are suitable for certain special applications. The overall scheme validated the feasibility of different regions of the parameter space and the controllability of product performance. This embodiment is applicable to the preparation of low-functionality polyurethane elastomer materials, particularly suitable for applications requiring special elasticity and flexibility, such as polyurethane elastic flooring materials, polyurethane hoses, and polyurethane sealing materials, which require higher molecular weight and good elastic recovery properties.

[0254] Comparative Example 1: Basically the same as Example 1, except that the mass ratio of triethanolamine to phosphoramide diol is 90:15, and the amounts of other components and preparation conditions remain unchanged.

[0255] Comparative Example 2: It is basically the same as Example 1, except that the mass ratio of triethanolamine to phosphoramide diol is 320:15, and the amounts of other components and preparation conditions remain unchanged.

[0256] Comparative Example 3: It is basically the same as Example 1, except that the hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol is 260 mg KOH / g, and the amount of other components and preparation conditions remain unchanged.

[0257] Comparative Example 4: Basically the same as Example 1, except that the hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol is 470 mg KOH / g, and the amounts of other components and preparation conditions remain unchanged.

[0258] Comparative Example 5: It is basically the same as Example 1, except that the amount of phosphorus pentoxide used is 0.3 wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol, while the amounts of other components and preparation conditions remain unchanged.

[0259] Comparative Example 6: It is basically the same as Example 1, except that the amount of phosphorus pentoxide used is 5.5 wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol, while the amounts of other components and preparation conditions remain unchanged.

[0260] Comparative Example 7: Basically the same as Example 1, except that phosphoramide diol is not used, only triethanolamine is used as the initiator, the amount of triethanolamine is 215 parts by mass, the amount of propylene oxide is adjusted accordingly to make the hydroxyl value reach 365 mg KOH / g, step S1 is omitted, and other preparation conditions remain unchanged.

[0261] Comparative Example 8: It is basically the same as Example 1, except that the phosphorylation reaction temperature in step S3-C2 is 40°C, while the amount of other components and preparation conditions remain unchanged.

[0262] Characterization tests:

[0263] Experiment 1: Apparent Viscosity Test

[0264] Test Subject: Reactive flame-retardant polyether polyol finished product. Test Objective: To evaluate the product's flowability and processing performance, and to verify whether the problem of limited processing window caused by increased viscosity has been resolved. Test Principle: The steady-state apparent viscosity of the polyether polyol at a specific temperature and shear rate is measured using a rotational rheometer. Lower viscosity indicates better flowability and processing performance. Experimental Method: A rotational rheometer with a cone-plate geometry (cone angle 2°, cone diameter 40mm, gap 50μm) is used. The sample is placed on a 25℃ constant temperature platform and allowed to equilibrate for 5 minutes. Then, a 10s application of [a specific material] is applied. -1 A constant shear rate was applied, and the steady-state apparent viscosity was recorded after the rheological curve stabilized. Key parameters: test temperature 25±0.5℃, shear rate 10s. -1 Equilibration time: 5 minutes; at least 3 parallel samples should be tested. Data processing: Calculate the mean and standard deviation, in mPa·s.

[0265] Experiment 2: Limiting Oxygen Index (LOI) Test

[0266] Test Object: Rigid polyurethane foam material prepared using the reactive flame-retardant polyether polyol of this embodiment. Test Objective: To evaluate the flame-retardant performance of the material and verify the effectiveness of the phosphorus-nitrogen synergistic flame-retardant mechanism. Test Principle: The sample is ignited in an oxygen-nitrogen mixed gas flow. The oxygen concentration is gradually adjusted, and the minimum oxygen concentration at which the material can sustain combustion is determined. A higher LOI value indicates better flame-retardant performance. Experimental Method: Polyether polyol and isocyanate are mixed at a hydroxyl to isocyanate equivalent ratio of 1:1.05 to prepare foam samples with dimensions of 150mm × 10mm × 10mm. The top of the sample is ignited in an oxygen-nitrogen mixed gas flow, and the percentage of the minimum oxygen concentration required for sustained combustion or smoldering for more than 3 minutes is recorded. Key Parameters: Sample size 150×10×10mm, gas flow rate 40±2mm / s, ignition time 30s, at least 5 samples tested. Data Processing: The median is taken as the LOI value, in vol%.

[0267] Experiment 3: UL-94 Vertical Burning Test

[0268] Test Object: Rigid polyurethane foam material prepared using the reactive flame-retardant polyether polyol of this embodiment. Test Objective: To evaluate the flame retardancy rating of the material and verify whether it can achieve a V-0 or V-1 rating. Test Principle: The sample is placed vertically, and the bottom end is ignited twice with a standard flame. The burning time, dripping pattern, and whether the flaming combustion spreads to the clamping end are recorded. The flame retardancy rating is determined based on the criteria. Experimental Method: Polyether polyol and isocyanate are mixed at a hydroxyl to isocyanate equivalent ratio of 1:1.05 to prepare a 12.5mm thick foam board. This board is cut into 125mm × 12.5mm samples, suspended vertically, and ignited with a 20mm blue flame for 10s. After removing the flame, the flaming combustion time t1 and the flameless combustion time t2 are recorded. After extinguishing, the sample is re-ignited for 10s, and t3 and t4 are recorded. Key Parameters: Flame height 20mm, ignition time 10s, number of samples 5. Data processing: Determine the V-0, V-1, or V-2 level based on t1+t2, t3+t4, and the droplet characteristics.

[0269] Experiment 4: Cone Calorimetry Test

[0270] Test Object: Rigid polyurethane foam material prepared using the reactive flame-retardant polyether polyol of this embodiment. Test Objective: To evaluate the heat release rate, smoke generation, and toxic gas release during combustion of the material, and to verify its low-smoke and low-toxicity performance. Test Principle: The sample is ignited under a constant radiative heat flux. The heat release rate is determined using the oxygen consumption principle. Simultaneously, smoke density and CO and CO2 production are measured to assess the fire hazard of the material. Experimental Method: The foam material is prepared into 100mm×100mm×50mm samples, placed horizontally under a cone calorimeter, and a radiative heat flux of 50kW / m² is applied. After ignition, parameters such as heat release rate (HRR), total heat release rate (THR), peak heat release rate (pHRR), smoke generation rate (SPR), and CO production are recorded. Key Parameters: Radiative heat flux 50kW / m², sample size 100×100×50mm, at least 3 samples tested. Data Processing: Average pHRR, THR, total smoke release rate (TSR), mean, and standard deviation are calculated.

[0271] Experiment 5: Polyurethane Foam Compressive Strength Test

[0272] Test Object: Rigid polyurethane foam material prepared using the reactive flame-retardant polyether polyol of this embodiment. Test Objective: To evaluate the mechanical strength of the foam material and verify the contribution of ion pairs to the crosslinking density and mechanical properties. Test Principle: A compressive load is applied to the foam sample, and the stress at 10% strain or failure is measured to assess the material's load-bearing capacity. Experimental Method: The foam material is prepared into 50mm × 50mm × 50mm cubic specimens and compressed at a compression rate of 5mm / min on a universal testing machine. The stress-strain curve is recorded, and the stress at 10% strain is taken as the compressive strength. Key Parameters: Specimen size 50×50×50mm, compression rate 5mm / min, temperature 23±2℃, humidity 50±5%RH, at least 5 specimens tested. Data Processing: The mean and standard deviation are calculated, in kPa.

[0273] Experiment 6: Chemical State Analysis of XPS Surface

[0274] Test Subject: Reactive flame-retardant polyether polyol solid sample. Test Objective: To analyze the chemical states and binding energies of phosphorus and nitrogen elements, and to verify the formation of phosphate ester groups and triethanolamine salt ion pairs. Test Principle: X-ray photoelectron spectroscopy is used to analyze the binding energies and chemical states of elements on the sample surface. The positions and peak fitting of the P 2p and N 1s spectra are used to confirm the phosphate ester bond (POC), phosphoramide bond (PN), and protonated amine (NH4+) bonds. +The presence of [a specific substance / factor]. Experimental method: After freeze-drying the sample, it was prepared into a thin film and excited under ultra-high vacuum conditions with monochromatic AlKα rays (hν=1486.6eV). The P 2p (binding energy 124-138eV) and N 1s (binding energy 395-405eV) regions were scanned, and the characteristic peaks were fitted using a Gaussian-Lorentz mixture function for peak separation. Key parameters: Vacuum degree <5×10 [a specific value / value]. -7 Pa, energy resolution ≤0.5 eV, C1s peak calibrated to 284.8 eV. Data processing: Binding energy-intensity CSV data were exported, and peaks were fitted and the proportion of each chemical state was calculated using Origin software.

[0275] Figure 1 The XPS P2p high-resolution spectra of Example 1 and Comparative Example 7 are shown. The basic parameters are binding energy range of 128 to 136 eV with reversed binding energy axis, normalized intensity display, and measured curves. The variable parameters are sample type Example 1 and Comparative Example 7, as well as the difference in P2p peak shape and intensity between the two. The results show that Example 1 exhibits a more explicit phosphorus-containing chemical state response in the P2p characteristic region, while Comparative Example 7 has a weak or absent response. The conclusion is that the phosphorus-containing structure of Example 1 has a detectable chemical presence on the surface, which is consistent with its flame-retardant design, indicating that the scheme is reasonable in introducing phosphorus-containing groups.

[0276] Figure 2 The XPS N 1s high-resolution spectra of Example 1 and Comparative Example 7 are shown. The basic parameters are binding energy range of 398 to 403 eV with reversed binding energy axis, intensity normalization, and measured curves. The variable parameters are sample type (Example 1 and Comparative Example 7) and differences in N1s peak position and shape. The results show that Example 1 shows a more obvious nitrogen-containing chemical state signal in the N1s region, while the signal in Comparative Example 7 is significantly weakened. The conclusion is that the nitrogen-containing structure of Example 1 is confirmed on the surface, which is consistent with the idea of ​​constructing a nitrogen-containing synergistic structure, indicating that the scheme is correct and reasonable in terms of surface chemical composition regulation.

[0277] Figure 3 The FTIR spectra of Example 1 and Comparative Example 7 are shown below, with the basic parameters being a wavenumber range of 900 to 1700 cm⁻¹. -1 Furthermore, the wavenumber axis was reversed, the absorption intensity was normalized, and the line shape was the measured spectrum; the variable parameters were the sample type Example 1 and Comparative Example 7, as well as the changes in the intensity and shape of the characteristic absorption bands; the results showed that Example 1 exhibited a more prominent absorption response in the characteristic bands related to phosphorus and oxygen and nitrogen, while Comparative Example 7 was weaker or not obvious; the conclusion is that Example 1 formed a functional group structure combination consistent with the design, which supports the rationality of the material construction path from the perspective of molecular vibration.

[0278] Figure 4The XPS P 2p peak fitting diagram for Example 1 is shown. The basic parameters are binding energy range of 128 to 136 eV with inversion and intensity normalization. The measured curve and the overall fitting curve are given, and peak decomposition is performed. The variable parameters are the relative contributions of the two components, phosphoramide P and phosphate ester P, and the corresponding peak shape fitting results. The results show that the overall fitting can fit the measured spectrum, and both phosphate ester P and phosphoramide P components contribute after peak separation. The conclusion is that the P chemical state composition of Example 1 can be explained by two types of phosphorus-containing structures, proving that the set structural origin and surface chemical state distribution are self-consistent.

[0279] Figure 5 The XPS P 2p peak fitting diagram for Comparative Example 5 is shown. The basic parameters are binding energy range of 128 to 136 eV with inverse polarity, intensity normalization, and the measured, fitted, and peak fitting results presented in the same diagram. The variable parameters are the proportion of phosphoramide P and phosphate ester P components and the peak shape difference in Comparative Example 5. The results show that the P 2p response of Comparative Example 5 is significantly different from that of Example 1 in terms of component contribution or overall intensity. The conclusion is that different formulations or structural pathways can lead to changes in the distribution of phosphorus-containing chemical states on the surface. From a comparative perspective, this shows that the design of Example 1 can more effectively form the target phosphorus-containing structure, demonstrating the rationality of the scheme.

[0280] Figure 6 The XPS P2p peak fitting diagram for Comparative Example 8 is shown. The basic parameters are binding energy range of 128 to 136 eV with inversion, intensity normalization, and the measured fitting and peak fitting are the same as those in the diagram. The variable parameters are the peak contribution and peak shape of phosphoramide P and phosphate ester P in Comparative Example 8. The results show that the component structure of Comparative Example 8 in the P2p characteristic region is inconsistent with that of Example 1 or the contribution of the target component is insufficient. The conclusion is that Example 1 is closer to the expected phosphorus-containing chemical state composition, and the comparative sample is difficult to meet this composition at the same time, indicating that the example path is more effective in surface chemical construction.

[0281] Figure 7 The XPS N1s peak fitting diagram for Example 1 is shown. The basic parameters are the binding energy range of 398 to 403 eV with inverse polarity, intensity normalization, and the comparison between the measured curve and the overall fitted curve, with component decomposition. The variable parameters are the relative proportions and peak position contributions of the two types of components: free amine N and protonated amine N. The results show that the fitted curve matches the measured curve, and the two types of nitrogen chemical states can be distinguished and jointly contribute to the N1s signal. The conclusion is that the nitrogen-containing structure on the surface of Example 1 has a clear chemical state distribution characteristic, providing evidence for the formation of a stable interfacial chemical environment, and proving that the design scheme is chemically reasonable.

[0282] Figure 8The XPS N1s peak fitting diagram for Comparative Example 7 is shown. The basic parameters are binding energy range of 398 to 403 eV with inversion, intensity normalization, and the same experimental fitting and component decomposition diagram. The variable parameters are the contributions of free amine N and protonated amine N in Comparative Example 7 and their differences from those in Example 1. The results show that the N1s signal of Comparative Example 7 is generally weak and the contribution of decomposable components is insufficient or missing. The conclusion is that Comparative Example 7 is difficult to form the same nitrogen-containing chemical state structure as Example 1, which, from the perspective of counter-evidence, shows that the construction route of Example 1 can better achieve the target surface chemical characteristics.

[0283] Figure 9 The image shows a macroscopic photograph of the ionomer-type reactive flame-retardant polyether polyol prepared in Example 1. The sample is a colorless to pale amber transparent high-viscosity fluid at room temperature, with overall uniformity and no visible precipitates or impurity particles. The high viscosity is consistent with the expected design of its ionomer molecular structure, indicating that the strict nitrogen protection and post-treatment impurity removal steps in the synthesis process effectively control oxidation byproducts. This proves that the preparation scheme can stably obtain the target product with the expected appearance quality.

[0284] Figure 10 The images shown are scanning electron microscope (SEM) images of the reactive flame-retardant polyether polyol from Example 1. The basic parameters are the morphology of the sample after obtaining observable surfaces and cross-sections through film formation or freeze-fracture and then conducting conductivity treatment, collected at different magnifications. The variable parameters are the content of ion pair structural units in the system determined by the neutralization degree of 85.7% and the removal effect of the 5μm filter pore size on micron-sized salt particles. In the low-magnification field of view, the sample shows a continuous phase coverage without a large number of micron-sized particles or crack networks. At medium and high magnifications, the sample mainly shows a smooth matrix with slight nanoscale undulations. The conclusion is that the sample maintains single-phase continuity and high cleanliness at the micron scale while exhibiting weak nanoscale heterogeneity, which is consistent with the structural expectation of ionomers forming ion-enriched domains without macroscopic phase separation. This proves that the filtration desalination and neutralization salt formation route can obtain a morphologically uniform and reproducible reactive flame-retardant polyether polyol system.

[0285] Table 1. Performance comparison data of the embodiments and comparative examples.

[0286] Sample number Apparent viscosity (mPa·s) LOI (vol%) UL-94 rating pHRR (kW / m²) Compressive strength (kPa) Phosphate content (at%) Example 1 6000±180 28.5±0.6 V-0 125±8 185±12 32.5±1.2 Example 2 7500±220 30.2±0.7 V-0 98±6 210±15 38.8±1.5 Example 3 4500±150 26.8±0.5 V-1 145±10 165±10 28.2±1.0 Example 4 8500±250 24.5±0.8 V-1 168±12 148±11 22.5±0.9 Comparative Example 1 4200±180 24.2±0.9 V-2 195±15 142±13 26.8±1.3 Comparative Example 2 9800±320 22.8±1.0 V-2 215±18 118±10 28.5±1.2 Comparative Example 3 3800±150 25.5±0.7 V-2 172±11 158±12 30.2±1.1 Comparative Example 4 11200±380 23.0±1.1 HB 238±20 102±9 31.8±1.4 Comparative Example 5 5800±190 23.8±0.8 V-2 188±14 168±13 18.5±0.8 Comparative Example 6 7200±240 25.2±0.9 V-1 162±12 175±14 42.5±1.8 Comparative Example 7 5500±170 22.5±1.0 HB 225±17 172±12 28.0±1.1 Comparative Example 8 6800±210 24.0±0.9 V-2 178±13 178±13 21.2±0.9

[0287] As can be seen from the performance of the examples and comparative examples in Table 1, the overall performance of Examples 1-4 is significantly better than that of the comparative examples, fully verifying the superiority of the technical solution of the present invention. Comparative Example 1: Due to the low mass ratio of triethanolamine to phosphoramide diol, the triethanolamine ratio was too low, resulting in insufficient formation of the nitrogen-phosphorus synergistic structure, leading to a decrease in both flame retardant performance and mechanical strength. Comparative Example 2: Due to the high mass ratio, the triethanolamine ratio was too high and the phosphoramide diol ratio was too low, resulting in a significant increase in system viscosity, deterioration of flowability and processing performance, and no improvement in flame retardant performance. Comparative Example 3: Due to the low hydroxyl value, the molecular weight was too high, resulting in a decrease in viscosity, but both flame retardant performance and mechanical strength decreased. Comparative Example 4: Due to the high hydroxyl value, the molecular weight was too low, resulting in a significant increase in viscosity, a significant decrease in mechanical strength, and a significant deterioration in flame retardant performance. Comparative Example 5: Due to insufficient phosphorus pentoxide content, the degree of phosphoric acid esterification was low, and the phosphate ester structure content was insufficient, resulting in a significant decrease in flame retardant performance. Comparative Example 6: Due to excessive phosphorus pentoxide content, although the phosphate ester content increased, it led to increased acidity and side reactions in the system, resulting in a decrease in performance balance. Comparative Example 7, lacking the key component phosphoramide diol, could not form a phosphoramide structure, resulting in a loss of the nitrogen-phosphorus synergistic effect and a significant decrease in flame retardant performance. Comparative Example 8, due to its excessively low phosphate esterification temperature, resulted in incomplete reaction and insufficient phosphate ester content, leading to a marked decrease in flame retardant performance. The combined data indicate that this invention, through optimized parameter ranges and the co-initiation design of phosphoramide diol and triethanolamine, successfully achieved a good balance between flame retardant performance, flow processing performance, and mechanical strength.

[0288] 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 reactive flame-retardant polyether polyol, characterized in that, The reactive flame-retardant polyether polyol is an ionomer polyether polyol containing phosphate groups and triethanolamine salt ion-pair structural units formed by the phosphate groups and triethanolamine. The reactive flame-retardant polyether polyol is obtained by reacting the following raw materials: triethanolamine; diethanolamine; diethyl chlorophosphate; triethylamine; propylene oxide; potassium hydroxide; phosphorus pentoxide; phosphoric acid; and nitrogen as a protective gas. The reactive flame-retardant polyether polyols described herein have the following quality control indicators: hydroxyl value of 280-450 mgKOH / g; acid value of 0.3-2.0 mgKOH / g; and water content of not more than 0.05 wt%.

2. The reactive flame-retardant polyether polyol as described in claim 1, characterized in that, The preparation process of the reactive flame-retardant polyether polyol includes the step of preparing phosphoramide diol, which includes the following steps: S1-A1: Raw material preparation: Diethanolamine and triethylamine are mixed under mechanical stirring conditions, with a molar ratio of diethanolamine to triethylamine of 1.00:1.00-1.05; S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 0-10℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is controlled at 1:1.00-1.05, and the feeding time is 0.5-2.0h. S1-A3: After the feeding is completed, raise the system temperature to 20-40℃ and keep it at that temperature for 1.0-4.0h. S1-A4: Post-treatment: Filter to remove the solid salt produced in the reaction, and then devolatilize at 50-90℃ and a vacuum of 0.1-5kPa for 0.5-2.0h; S1-A5: Endpoint Criteria and Quality Control: The chlorine content of the obtained phosphoramide diol is not higher than 0.10 wt%, and the phosphoramide diol is obtained.

3. The reactive flame-retardant polyether polyol as described in claim 1, characterized in that, The preparation process of the reactive flame-retardant polyether polyol includes the step of preparing aminophosphamide co-initiated polyoxypropylene polyol, which includes the following steps: S2-B1: Raw material preparation: Triethanolamine and phosphoramide diol are mixed in a mass ratio of 100-300:5-30, and potassium hydroxide is added, wherein the amount of potassium hydroxide is 0.05-0.20 wt% of the total mass of the triethanolamine and phosphoramide diol. S2-B2: Dehydration: The system is heated to 90-115℃ under a nitrogen atmosphere, then evacuated to 0.1-3kPa and dehydrated for 0.5-2.0h; S2-B3: Ring-opening polymerization: Control the system temperature at 95-125℃, add propylene oxide continuously under mechanical stirring, and maintain the system gauge pressure at 0.2-0.6MPa. Continue adding until the hydroxyl value of the obtained aminophosphamide co-initiated polyoxypropylene polyol is 280-450mgKOH / g; after the addition is completed, maintain the reaction temperature for 0.5-2.0h. S2-B4: Deviation and neutralization: Deviation is carried out at 90-120℃ and vacuum degree of 0.1-3kPa for 0.5-2.0h, followed by neutralization with the addition of phosphoric acid. The amount of phosphoric acid added is based on the mass of H3PO4 therein, and the endpoint is determined by the acid value of the aminophosphamide co-initiated polyoxypropylene polyol being 0.0-0.5mgKOH / g. S2-B5: Post-treatment: Filter to remove salt solids to obtain the aminophosphamide co-initiated polyoxypropylene polyol; S2-B6: Quality Control: The aminophosphamide co-initiated polyoxypropylene polyol has a hydroxyl value of 280-450 mg KOH / g and a water content of no more than 0.05 wt%.

4. The reactive flame-retardant polyether polyol as described in claim 1, characterized in that, The preparation process of the reactive flame-retardant polyether polyol includes the step of preparing acidic phosphoric acid esterified polyether polyol, which includes the following steps: S3-C1: Raw material preparation: Using aminophosphoramide co-initiated polyoxypropylene polyol as the reactant, phosphorus pentoxide and phosphoric acid are added, wherein the amount of phosphorus pentoxide is 0.5-5.0 wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid (calculated as H3PO4) is 0.2-3.0 wt% of the mass of aminophosphoramide co-initiated polyoxypropylene polyol; S3-C2: Phosphorylation: Under a nitrogen atmosphere, the system temperature is controlled at 50-90℃ and the reaction is carried out for 1.0-5.0 h; S3-C3: Dehydration: Maintain the reaction temperature of step S3-C2 and dehydrate for 0.5-2.0 h under a vacuum of 0.1-3 kPa; S3-C4: Endpoint Criteria and Quality Control: The reaction is stopped when the acid value of the acidic phosphoric acid esterified polyether polyol is 3.0-12.0 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol is obtained.

5. The reactive flame-retardant polyether polyol as described in claim 1, characterized in that, The reactive flame-retardant polyether polyol has a hydroxyl functionality of 2-6.

6. A method for preparing a reactive flame-retardant polyether polyol as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Prepare phosphoramidide alcohol according to steps S1-A1 to S1-A5 as described in claim 2; S2: Prepare aminophosphamide co-initiated polyoxypropylene polyols according to steps S2-B1 to S2-B6 of claim 3; S3: Prepare acidic phosphoric acid esterified polyether polyols according to steps S3-C1 to S3-C4 of claim 4; S4: Preparation of ionomer-type reactive flame-retardant polyether polyols.

7. The preparation method according to claim 6, characterized in that, The preparation of phosphoramide diol in step S1 includes the following sub-steps: S1-A1: Diethanolamine and triethylamine are mixed under mechanical stirring conditions, with a molar ratio of diethanolamine to triethylamine of 1.00:1.00-1.05; S1-A2: Under a nitrogen atmosphere, the system temperature is controlled at 0-10℃, and diethyl chlorophosphate is added continuously. The molar ratio of diethyl chlorophosphate to diethanolamine is 1:1.00-1.05, and the feeding time is 0.5-2.0h. S1-A3: After the feeding is completed, raise the system temperature to 20-40℃ and keep it at that temperature for 1.0-4.0h. S1-A4: Filter to remove the solid salt produced in the reaction, and then devolatilize at 50-90℃ and a vacuum of 0.1-5kPa for 0.5-2.0h; S1-A5: The chlorine content of the obtained phosphoramidide diol is not higher than 0.10 wt%, thus obtaining phosphoramidide diol.

8. The preparation method according to claim 6, characterized in that, The preparation of aminophosphamide co-initiated polyoxypropylene polyol in step S2 includes the following sub-steps: S2-B1: Mix triethanolamine and phosphoramidol in a mass ratio of 100-300:5-30, and add potassium hydroxide in an amount of 0.05-0.20 wt% of the total mass of triethanolamine and phosphoramidol. S2-B2: Heat the system to 90-115℃ under a nitrogen atmosphere, then evacuate to 0.1-3kPa and dehydrate for 0.5-2.0h; S2-B3: Control the system temperature at 95-125℃, add propylene oxide continuously under mechanical stirring, and maintain the system gauge pressure at 0.2-0.6MPa. Continue adding until the hydroxyl value of the obtained aminophosphamide co-initiated polyoxypropylene polyol is 280-450mgKOH / g; after the addition is completed, keep the reaction at the temperature for 0.5-2.0h. S2-B4: Deviation is carried out at 90-120℃ and vacuum degree of 0.1-3kPa for 0.5-2.0h, followed by neutralization with phosphoric acid. The amount of phosphoric acid added is based on the mass of H3PO4 therein, and the endpoint is determined by the acid value of the aminophosphamide co-initiated polyoxypropylene polyol being 0.0-0.5mgKOH / g. S2-B5: Filter to remove salt solids to obtain aminophosphamide co-initiated polyoxypropylene polyol; S2-B6: The hydroxyl value of the aminophosphamide co-initiated polyoxypropylene polyol is 280-450 mg KOH / g and the water content is not higher than 0.05 wt%.

9. The preparation method according to claim 6, characterized in that, Step S3 includes the following sub-steps: S3-C1: Using aminophosphoramide co-initiated polyoxypropylene polyol as a reactant, phosphorus pentoxide and phosphoric acid are added. The amount of phosphorus pentoxide is 0.5-5.0 wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol, and the amount of phosphoric acid (calculated as H3PO4) is 0.2-3.0 wt% of the mass of the aminophosphoramide co-initiated polyoxypropylene polyol. S3-C2: Under a nitrogen atmosphere, the system temperature is controlled at 50-90℃ and the reaction is carried out for 1.0-5.0 h; S3-C3: Maintain the reaction temperature of step S3-C2 and dehydrate for 0.5-2.0 h under a vacuum of 0.1-3 kPa; S3-C4: The reaction is stopped when the acid value of the acidic phosphoric acid esterified polyether polyol is 3.0-12.0 mg KOH / g, and the acidic phosphoric acid esterified polyether polyol is obtained.

10. The preparation method according to claim 6, characterized in that, Step S4 includes the following sub-steps: S4-D1: Raw material preparation: The acidic phosphoric acid esterified polyether polyol prepared in step S3 is used as a reactant, and triethanolamine is added. The amount of triethanolamine added is such that the acid value of the resulting ionomer-type reactive flame-retardant polyether polyol is 0.3-2.0 mgKOH / g. S4-D2: Neutralization to form salt: Reaction at 30-70℃ for 0.5-3.0 h; S4-D3: Endpoint Criterion and Quality Control: The reaction is stopped when the acid value of the ionomer-type reactive flame-retardant polyether polyol is 0.3-2.0 mg KOH / g, and triethanolamine salt ion-pair structural units are formed; S4-D4: Post-treatment: Maintain the reaction temperature of step S4-D2, and devolve under a vacuum of 0.1-3 kPa for 0.5-2.0 h to ensure that the water content of the ionomer-type reactive flame-retardant polyether polyol is not higher than 0.05 wt%, thereby obtaining the reactive flame-retardant polyether polyol.

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