Special composite antioxidant system for elastomer polyether as well as application and evaluation method of special composite antioxidant system

Abstract

The invention relates to the technical field of antioxidants and high polymer materials, and discloses a special composite antioxidant system for elastomer polyether as well as application and an evaluation method of the special composite antioxidant system. The composite antioxidant is formed by compounding a hindered phenol main antioxidant and a liquid composite phosphite auxiliary antioxidant, and is added into the elastomer polyether polyol according to a specific proportion. Through the synergistic effect of the two, oxidation yellowing generated in the process that elastomer polyether reacts with isocyanate to generate a prepolymer under the conditions of high temperature and oxygen introduction can be effectively inhibited, the color value of a system is remarkably reduced, and meanwhile the water stability of the system is kept. Compared with a single antioxidant or a conventional compound antioxidant, the composite antioxidant disclosed by the invention has a better application effect in the aspects of improving the color stability and long-term thermal stability of the elastomer polyether, and is suitable for the production, processing and storage processes of the elastomer polyether.

Description

Technical Field

[0001] This invention belongs to the field of antioxidant technology and polymer materials technology, specifically relating to a composite antioxidant system for elastomer polyether and its application and evaluation method. Background Technology

[0002] Elastomer polyether polyols are essential raw materials for the preparation of polyurethane foams, polyurethane elastomers, coatings, and adhesives. They are typically produced by ring-opening polymerization of small-molecule polyols, polyamines, or other compounds containing active hydrogen as initiators with epoxides. Depending on the application, polyether polyols can be classified into flexible foam polyethers, rigid foam polyethers, POP polyethers, CASE polyethers, and specialty polyethers. Among these, elastomeric polyethers are widely used due to their excellent mechanical and processing properties.

[0003] During the storage, processing, and use of elastomeric polyethers, especially under high-temperature and oxygen-filled conditions when reacting with isocyanates to prepare polyurethane prepolymers, elastomeric polyethers are prone to oxidation reactions, producing yellow or dark yellow discolored substances. This leads to a deterioration in the product's appearance, affecting its stability and the quality of downstream applications. This yellowing phenomenon mainly originates from the urethane structure formed during the reaction of the elastomeric polyether. This structure is easily further oxidized in high-temperature and high-oxygen-concentration environments, forming discolored substances.

[0004] To suppress the aforementioned oxidative yellowing phenomenon, antioxidants are typically added to elastomeric polyether systems. Antioxidants, acting as free radical terminators and hydroperoxide decomposers, can improve performance indicators such as oxidation induction temperature, aldehyde content, and thermal stability in polyether systems to a certain extent. In the prior art, hindered phenolic antioxidants are widely used in polyether polyol systems; however, a single hindered phenolic antioxidant may itself undergo oxidation under high-temperature conditions, generating a colored structure, which still fails to meet the requirements of long-term color stability and thermal stability for elastomeric polyethers.

[0005] In the industrial production of elastomeric polyethers, commonly used solid antioxidants suffer from problems such as high dust levels, poor dispersibility, and high volatile content, which can adversely affect the production environment and product uniformity. Therefore, how to further improve the antioxidant capacity and anti-yellowing properties of elastomeric polyether polyols during high-temperature processing and long-term storage through reasonable antioxidant system design, without affecting the bulk properties of the elastomeric polyether polyol, remains a pressing technical problem to be solved in this field. Summary of the Invention

[0006] To overcome the problems of oxidative yellowing and poor color stability of elastomeric polyether polyols during storage, processing, and high-temperature oxygenation reactions with isocyanates, as well as the limited antioxidant effect and poor dispersibility of single or solid antioxidants under high-temperature conditions, this invention aims to provide a composite antioxidant system specifically for elastomeric polyethers and its application and evaluation method. This invention employs a composite antioxidant system composed of a hindered phenolic primary antioxidant and a liquid composite phosphite secondary antioxidant. This system is added to the elastomeric polyether polyol in a specific ratio. Through the synergistic effect of the two, the oxidation reaction and color degradation of the elastomeric polyether under high-temperature oxygenation conditions are inhibited. Simultaneously, the all-liquid formulation improves the dispersion uniformity and application stability of the antioxidant in the system. This invention significantly improves the antioxidant stability and anti-yellowing performance during high-temperature processing and long-term storage without affecting the bulk properties of the elastomeric polyether polyol.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A composite antioxidant system for elastomeric polyethers, comprising the following components:

[0009] (i) Elastomer polyether polyols;

[0010] (ii) Hindered phenolic primary antioxidants;

[0011] (iii) Liquid complex phosphite-based auxiliary antioxidants;

[0012] The hindered phenolic primary antioxidant and the liquid composite phosphite secondary antioxidant work synergistically to inhibit oxidative yellowing of the elastomeric polyether during the reaction with isocyanate to form a prepolymer under high temperature and oxygen conditions, and to improve the long-term thermal stability of the elastomeric polyether.

[0013] Optionally, the hindered phenolic primary antioxidant is selected from one or more of the following: isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0014] Optionally, the liquid complex phosphite co-antioxidant is a complex of multiple components from the following substances: tri(12-15 alkyl) phosphite, poly(dipropylene glycol) phenyl phosphite, pentaerythritol diisodecyl diphosphite, triphenyl phosphite, diphenyl-isodecyl phosphite, and diphenyl-diisodecyl phosphite.

[0015] Optionally, the total amount of hindered phenolic primary antioxidant and liquid complex phosphite secondary antioxidant added is 0.05% to 0.1%.

[0016] Optionally, the total amount of hindered phenolic primary antioxidant and liquid complex phosphite secondary antioxidant added is 0.05%.

[0017] Optionally, 20-30 parts of hindered phenolic primary antioxidant; 70-80 parts of liquid complex phosphite secondary antioxidant; wherein the hindered phenolic primary antioxidant is isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate.

[0018] Optionally, the liquid complex phosphite-based co-antioxidant comprises the following components in weight percentage: 5%–20% poly(dipropylene glycol) phenyl phosphite; 10%–30% pentaerythritol diisodecyl diphosphite; 10%–30% triphenyl phosphite; 10%–50% diphenyl-isodecyl phosphite; and 10%–50% diphenyl-diisodecyl phosphite.

[0019] Optionally, a method for preparing a composite antioxidant system for elastomeric polyether includes the following steps: weighing the hindered phenolic primary antioxidant and the liquid composite phosphite secondary antioxidant according to the weight ratio of each component, and mechanically stirring in a closed constant temperature stirring vessel under constant temperature and constant speed conditions for 20-40 minutes to ensure that each component is fully mixed and uniformly dispersed to obtain the composite antioxidant for elastomeric polyether.

[0020] Optionally, an application of a composite antioxidant for elastomeric polyethers in elastomeric polyether polyols, wherein the composite antioxidant is added to the elastomeric polyether polyol at an addition amount of 0.05% to 0.5%, is used to improve the antioxidant properties and anti-yellowing properties of the elastomeric polyether under high temperature and oxygen-permeable conditions.

[0021] Optionally, after adding a composite antioxidant, the elastomeric polyether polyol reacts with isocyanate at 80°C to generate a prepolymer, which is then heated at 80–120°C for 2–4 hours and placed at 80°C for 48–96 hours. The stability of the elastomeric polyether is evaluated by color change and color value change.

[0022] The beneficial effects of this invention are:

[0023] This invention utilizes a specialized compounding of hindered phenolic primary antioxidants with various liquid phosphite secondary antioxidants, applying them in a fully liquid form to an elastomeric polyether polyol system. This invention constructs an antioxidant system highly matched to the reaction conditions of elastomeric polyethers, enabling the elastomeric polyether to effectively inhibit the formation of chromogenic substances during the reaction of the elastomeric polyether with isocyanates to form prepolymers under high temperature and oxygen-permeable conditions. This significantly reduces the color value of the system and maintains a clear and transparent state for a long time. Its anti-yellowing effect and thermal stability are significantly better than those of single hindered phenolic antioxidants, single phosphite antioxidants, and conventional compounded antioxidant systems, thereby achieving a targeted and long-lasting improvement in the color stability of elastomeric polyethers. Attached Figure Description

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] Figure 1 This is a color rendering of the elastomeric polyether prepolymer.

[0026] Figure 2 This is a diagram illustrating the storage stability of elastomeric polyethers.

[0027] Figure 3 This is a comparative example diagram of the effects of elastomer polyether prepolymer. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.

[0029] Example 1:

[0030] A composite antioxidant for elastomeric polyethers, comprising the following components: 1g component a (3,5-di-tert-butyl-4-hydroxyphenylpropionate isooctyl ester) and 9g component b.

[0031] Component b includes:

[0032] 5% poly(dipropylene glycol) phenyl phosphite (antioxidant PDP);

[0033] 10% pentaerythritol diisodecyl diphosphite;

[0034] 10% Triphenyl Phosphite (antioxidant TPP);

[0035] 30% diphenyl isodecyl phosphite (antioxidant DPDP);

[0036] 45% phenyl diisodecyl phosphite (antioxidant PDDP).

[0037] The mixture is stirred at a constant temperature and speed in a sealed, constant-temperature stirring vessel for 20-40 minutes to ensure that the components in the composite antioxidant are evenly dispersed.

[0038] Evaluation of the application of elastomeric polyether polyol: First, the elastomeric polyether polyol was mixed with isocyanate at 80°C to prepare a prepolymer. The prepolymer system was continuously stirred and heated in a constant temperature environment of 80-120°C for 2-4 hours. Then, it was placed in a constant temperature environment of 80°C for 48-96 hours to observe the color change of the prepolymer system. The stability of the elastomeric polyether was examined by the color change.

[0039] Example 2:

[0040] A composite antioxidant for elastomeric polyethers, comprising the following components: 2g component a and 8g component b.

[0041] Component b includes:

[0042] 5% poly(dipropylene glycol) phenyl phosphite (antioxidant PDP);

[0043] 10% pentaerythritol diisodecyl diphosphite;

[0044] 10% Triphenyl Phosphite (antioxidant TPP);

[0045] 30% diphenyl isodecyl phosphite (antioxidant DPDP);

[0046] 45% phenyl diisodecyl phosphite (antioxidant PDDP).

[0047] The mixture is stirred at a constant temperature and speed in a sealed, constant-temperature stirring vessel for 20-40 minutes to ensure that the components in the composite antioxidant are evenly dispersed.

[0048] Evaluation of the application of elastomeric polyether polyol: First, the elastomeric polyether polyol was mixed with isocyanate at 80°C to prepare a prepolymer. The prepolymer system was continuously stirred and heated in a constant temperature environment of 80-120°C for 2-4 hours. Then, it was placed in a constant temperature environment of 80°C for 48-96 hours to observe the color change of the prepolymer system. The stability of the elastomeric polyether was examined by the color change.

[0049] Example 3:

[0050] A composite antioxidant for elastomeric polyethers, comprising the following components: 3g component a and 7g component b.

[0051] Component b includes:

[0052] 5% poly(dipropylene glycol) phenyl phosphite (antioxidant PDP);

[0053] 10% pentaerythritol diisodecyl diphosphite;

[0054] 10% Triphenyl Phosphite (antioxidant TPP);

[0055] 30% diphenyl isodecyl phosphite (antioxidant DPDP);

[0056] 45% phenyl diisodecyl phosphite (antioxidant PDDP).

[0057] The mixture is stirred at a constant temperature and speed in a sealed, constant-temperature stirring vessel for 20-40 minutes to ensure that the components in the composite antioxidant are evenly dispersed.

[0058] Evaluation of the application of elastomeric polyether polyol: First, the elastomeric polyether polyol was mixed with isocyanate at 80°C to prepare a prepolymer. The prepolymer system was continuously stirred and heated in a constant temperature environment of 80-120°C for 2-4 hours. Then, it was placed in a constant temperature environment of 80°C for 48-96 hours to observe the color change of the prepolymer system. The stability of the elastomeric polyether was examined by the color change.

[0059] Example 4:

[0060] A composite antioxidant for elastomeric polyethers, comprising the following components: 3g component a and 7g component b.

[0061] Component b includes:

[0062] 7.5% poly(dipropylene glycol) phenyl phosphite (antioxidant PDP);

[0063] 15% pentaerythritol diisodecyl diphosphite;

[0064] 15% Triphenyl Phosphite (antioxidant TPP);

[0065] 30% diphenyl isodecyl phosphite (antioxidant DPDP);

[0066] 32.5% phenyl diisodecyl phosphite (antioxidant PDDP).

[0067] The mixture is stirred at a constant temperature and speed in a sealed, constant-temperature stirring vessel for 20-40 minutes to ensure that the components in the composite antioxidant are evenly dispersed.

[0068] Evaluation of the application of elastomeric polyether polyol: First, the elastomeric polyether polyol was mixed with isocyanate at 80°C to prepare a prepolymer. The prepolymer system was continuously stirred and heated in a constant temperature environment of 80-120°C for 2-4 hours. Then, it was placed in a constant temperature environment of 80°C for 48-96 hours to observe the color change of the prepolymer system. The stability of the elastomeric polyether was examined by the color change.

[0069] Example 5:

[0070] A composite antioxidant for elastomeric polyethers, comprising the following components: 3g component a and 7g component b.

[0071] Component b includes:

[0072] 10% poly(dipropylene glycol) phenyl phosphite (antioxidant PDP);

[0073] 15% pentaerythritol diisodecyl diphosphite;

[0074] 15% Triphenyl Phosphite (antioxidant TPP);

[0075] 20% diphenyl isodecyl phosphite (antioxidant DPDP);

[0076] 40% phenyl diisodecyl phosphite (antioxidant PDDP).

[0077] The mixture is stirred at a constant temperature and speed in a sealed, constant-temperature stirring vessel for 20-40 minutes to ensure that the components in the composite antioxidant are evenly dispersed.

[0078] Evaluation of the application of elastomeric polyether polyol: First, the elastomeric polyether polyol was mixed with isocyanate at 80°C to prepare a prepolymer. The prepolymer system was continuously stirred and heated in a constant temperature environment of 80-120°C for 2-4 hours. Then, it was placed in a constant temperature environment of 80°C for 48-96 hours to observe the color change of the prepolymer system. The stability of the elastomeric polyether was examined by the color change.

[0079] Example 6:

[0080] A composite antioxidant for elastomeric polyethers, comprising the following components: 3g component a and 7g component b.

[0081] Component b includes:

[0082] 10% poly(dipropylene glycol) phenyl phosphite (antioxidant PDP);

[0083] 20% pentaerythritol diisodecyl diphosphite;

[0084] 20% Triphenyl Phosphite (antioxidant TPP);

[0085] 25% diphenyl isodecyl phosphite (antioxidant DPDP);

[0086] 25% phenyl diisodecyl phosphite (antioxidant PDDP).

[0087] The mixture is stirred at a constant temperature and speed in a sealed, constant-temperature stirring vessel for 20-40 minutes to ensure that the components in the composite antioxidant are evenly dispersed.

[0088] Evaluation of the application of elastomeric polyether polyol: First, the elastomeric polyether polyol was mixed with isocyanate at 80°C to prepare a prepolymer. The prepolymer system was continuously stirred and heated in a constant temperature environment of 80-120°C for 2-4 hours. Then, it was placed in a constant temperature environment of 80°C for 48-96 hours to observe the color change of the prepolymer system. The stability of the elastomeric polyether was examined by the color change.

[0089] Example 7:

[0090] A composite antioxidant for elastomeric polyethers, comprising the following components: 3g component a and 7g component b.

[0091] Component b includes:

[0092] 10% poly(dipropylene glycol) phenyl phosphite (antioxidant PDP);

[0093] 10% pentaerythritol diisodecyl diphosphite;

[0094] 10% Triphenyl Phosphite (antioxidant TPP);

[0095] 50% diphenyl isodecyl phosphite (antioxidant DPDP);

[0096] 20% phenyl diisodecyl phosphite (antioxidant PDDP).

[0097] The mixture is stirred at a constant temperature and speed in a sealed, constant-temperature stirring vessel for 20-40 minutes to ensure that the components in the composite antioxidant are evenly dispersed.

[0098] Evaluation of the application of elastomeric polyether polyol: First, the elastomeric polyether polyol was mixed with isocyanate at 80°C to prepare a prepolymer. The prepolymer system was continuously stirred and heated in a constant temperature environment of 80-120°C for 2-4 hours. Then, it was placed in a constant temperature environment of 80°C for 48-96 hours to observe the color change of the prepolymer system. The stability of the elastomeric polyether was examined by the color change.

[0099] Example 8:

[0100] The elastomeric polyether-specific composite antioxidant from Example 5 was uniformly mixed and added to the elastomeric polyether at a concentration of 0.05%–0.15%. The product was then exposed to direct sunlight for 72–96 hours to observe the effect of the composite antioxidant on the stability of the elastomeric polyether product.

[0101] Comparative Example 1:

[0102] The comparative example is a single agent of antioxidant 1135 (3,5-di-tert-butyl-4-hydroxyphenylpropionate isooctyl ester).

[0103] Comparative Example 2:

[0104] The comparative example is antioxidant 168 (tris[2,4-di-tert-butylphenyl]phosphite) as a single agent.

[0105] Comparative Example 3:

[0106] The comparative example is a compound antioxidant, comprising 3g of antioxidant 1135 (3,5-di-tert-butyl-4-hydroxyphenylpropionate isooctyl ester) and 7g of antioxidant 168 (tris[2,4-di-tert-butylphenyl]phosphite).

[0107] Performance testing:

[0108] 1. Color Appearance Test Method

[0109] Elastomer polyether samples with corresponding antioxidant systems added in different embodiments and comparative examples were visually observed under natural light after high-temperature reaction treatment or storage treatment. By comparing the overall appearance of the samples, their color was categorized as clear and transparent, slightly yellow, or deep yellow, to evaluate the inhibitory effect of different antioxidant systems on the oxidative yellowing of elastomeric polyethers. This method can directly reflect the differences in color stability of elastomeric polyethers under high-temperature, oxygen-permeable, and storage conditions.

[0110] 2. Moisture content test method

[0111] The moisture content of the elastomeric polyether samples obtained in the examples and comparative examples was tested to determine the mass percentage of moisture in the samples. By comparing the moisture data of different samples, the moisture stability of the elastomeric polyether system after adding different antioxidant systems was evaluated to verify whether the introduction of composite antioxidants has an adverse effect on the system stability of elastomeric polyethers.

[0112] 3. Color Value (Hazen Value) Testing Method

[0113] Color values ​​were tested on the treated elastomeric polyether samples from the examples and comparative examples, using the Hazen value as a quantitative evaluation index for color. By measuring and comparing the Hazen values ​​of each sample, the degree of color change of the elastomeric polyether under the action of different antioxidant systems was quantitatively reflected. The lower the Hazen value, the lighter the sample color and the better the anti-yellowing performance, thus it can be used to evaluate the effect of the antioxidant system on the color stability of the elastomeric polyether.

[0114] Table 1 Performance Test Results

[0115]

[0116]

[0117] As shown in Table 1, different antioxidant systems exhibited significant differences in the color appearance, moisture content, and Hazen value of the elastomeric polyether. The blank group samples appeared deep yellow under the test conditions, with a Hazen value as high as 355.54, indicating that without the addition of antioxidants, the elastomeric polyether was highly susceptible to significant oxidative yellowing during high temperatures, oxygenation, and storage. In contrast, the samples from the examples containing the composite antioxidant system of this invention maintained a clear and transparent appearance, demonstrating that the composite antioxidant effectively inhibited the formation of chromogenic substances.

[0118] Further analysis of the color value data revealed that the Hazen values ​​of Examples 1 through 7 were significantly lower than those of the comparative example. Specifically, the Hazen values ​​of Examples 3, 5, and 6 were 17.89, 13.65, and 15.21, respectively, which are at a relatively low level, demonstrating that the composite antioxidant system of the present invention exhibits stable and excellent anti-yellowing effects under different formulation conditions. Example 8 remained clear and transparent even under natural light exposure, with its Hazen value further decreasing to 10.96. This indicates that the composite antioxidant not only performs well under high-temperature processing and storage conditions but also significantly improves the stability of the elastomeric polyether under light exposure.

[0119] The moisture content results show that the moisture content of both the example and the comparative sample remained within a narrow range of 0.008% to 0.010%, without significant fluctuations. This indicates that the introduction of the composite antioxidant of the present invention will not have an adverse effect on the moisture stability of the elastomer polyether system, and its performance improvement is mainly reflected in the effective inhibition of oxidative yellowing.

[0120] The comparative results further verified the advantages of the present invention. Comparative Examples 1 and 2 were treated with hindered phenolic antioxidants and phosphite antioxidants, respectively, and their samples were all deep yellow, with Hazen values ​​still as high as 210.21 and 159.68. Comparative Example 3 used a conventional combination system of hindered phenolic and phosphite antioxidants. Although the color was improved, the Hazen value was still 66.69, which was significantly higher than that of the embodiments of the present invention.

[0121] In summary, the elastomeric polyether-specific composite antioxidant system of the present invention can significantly reduce the color value of elastomeric polyether and effectively inhibit yellowing without affecting the moisture stability of the system. Its antioxidant and color stability performance is significantly better than that of single antioxidants and conventional compound antioxidant systems, demonstrating outstanding specialization and long-term stability advantages.

Claims

1. A composite antioxidant system specifically for elastomer polyethers, characterized in that, Includes the following components: (i) Elastomer polyether polyols; (ii) Hindered phenolic primary antioxidants; (iii) Liquid complex phosphite-based auxiliary antioxidants; The hindered phenolic primary antioxidant and the liquid composite phosphite secondary antioxidant work synergistically to inhibit oxidative yellowing of the elastomeric polyether during the reaction with isocyanate to form a prepolymer under high temperature and oxygen conditions, and to improve the long-term thermal stability of the elastomeric polyether.

2. The elastomeric polyether-specific composite antioxidant system according to claim 1, characterized in that, The hindered phenolic primary antioxidant is selected from one or more of the following: isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

3. The elastomeric polyether-specific composite antioxidant system according to claim 1, characterized in that, The liquid composite phosphite-based auxiliary antioxidant is a complex of multiple components from the following substances: tri(12-15 alkyl) phosphite, poly(dipropylene glycol) phenyl phosphite, pentaerythritol diisodecyl diphosphite, triphenyl phosphite, diphenyl-isodecyl phosphite, and diphenyl-diisodecyl phosphite.

4. The elastomeric polyether-specific composite antioxidant system according to claim 1, characterized in that, Based on the weight of the elastomeric polyether polyol, the total addition amount of the hindered phenolic primary antioxidant and the liquid composite phosphite secondary antioxidant is 0.05% to 0.1%.

5. The elastomeric polyether-specific composite antioxidant system according to claim 4, characterized in that, The total amount of the hindered phenolic primary antioxidant and the liquid complex phosphite secondary antioxidant added is 0.05%.

6. A composite antioxidant product specifically for elastomer polyethers, characterized in that, By weight, it includes: 20-30 parts of hindered phenolic primary antioxidant; 70-80 parts of liquid complex phosphite secondary antioxidant; wherein the hindered phenolic primary antioxidant is isooctyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate.

7. The elastomeric polyether-specific composite antioxidant product according to claim 6, characterized in that, The liquid composite phosphite-based auxiliary antioxidant comprises the following components in weight percentage: 5%–20% poly(dipropylene glycol) phenyl phosphite; 10%–30% pentaerythritol diisodecyl diphosphite; 10%–30% triphenyl phosphite; 10%–50% diphenyl isodecyl phosphite; and 10%–50% diphenyl diisodecyl phosphite.

8. A method for preparing a composite antioxidant system for elastomeric polyethers, wherein the composite antioxidant system for elastomeric polyethers is as described in any one of claims 1 to 7, characterized in that, Includes the following steps: According to the weight ratio of each component, the hindered phenolic primary antioxidant and the liquid composite phosphite secondary antioxidant are weighed and mechanically stirred in a closed constant temperature and constant speed reactor for 20-40 minutes to ensure that the components are fully mixed and uniformly dispersed, thus obtaining a special composite antioxidant for elastomeric polyether.

9. The application of a composite antioxidant specifically for elastomeric polyethers in elastomeric polyether polyols, wherein the composite antioxidant system for elastomeric polyethers is as described in any one of claims 1 to 7, characterized in that, The composite antioxidant is added to the elastomer polyether polyol at an addition amount of 0.05% to 0.5% to improve the antioxidant and anti-yellowing properties of the elastomer polyether under high temperature and oxygen-permeable conditions.

10. The application of the elastomeric polyether-specific composite antioxidant according to claim 9 in elastomeric polyether polyols, characterized in that, The elastomeric polyether polyol, after the addition of a composite antioxidant, reacts with isocyanate at 80°C to form a prepolymer, which is then heated at 80–120°C for 2–4 hours and placed at 80°C for 48–96 hours. The stability of the elastomeric polyether is evaluated by color change and color value change.

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