Preparation method and application of high-activity polymer polyol

Abstract

The invention provides a preparation method and application of high-activity polymer polyol, and the preparation method comprises the following steps: in the presence of an initiator and a chain transfer agent, polymerizing a macromonomer and an olefinic unsaturated monomer in high-activity polyether polyol, and carrying out devolatilization treatment to obtain the high-activity polymer polyol, according to the product obtained by the preparation method, polymer particles contain a multi-foam structure, and the prepared polyurethane foam has the characteristics of good compression performance, good bearing capacity and low density.

Description

Technical Field

[0001] This invention belongs to the field of polymer polyol preparation, and particularly relates to a method for preparing a high-resilience polymer polyol and its application. Background Technology

[0002] Polymer polyols (also known as grafted polyether polyols or filled polyols, abbreviated as POP) are dispersions of polymer particles in polyether polyols obtained through in-situ free radical polymerization of vinyl monomers. A common example is styrene-acrylonitrile copolymer polyol. They are primarily used in the production of flexible polyurethane foam. Polyurethane prepared using polymer polyols can improve the performance of flexible polyurethane foam, especially its hardness and load-bearing capacity. Depending on the application, they are divided into block flexible foam and molded foam materials. Block flexible foam is mainly used in home furnishings, footwear, and bags, primarily using ordinary flexible foam polyethers. Molded polyurethane foam materials are mainly used in the automotive and aerospace industries, often employing highly reactive polyether polyols, generally referring to polyether polyols with an EO content of 13-20% and a primary hydroxyl content of 70-90%. Highly reactive polymer polyols are prepared by grafting vinyl monomers onto a highly reactive base polyether polyol through in-situ free radical polymerization.

[0003] However, existing technologies do not consider application scenarios and do not differentiate or limit the polymer polyols used in the fields of high-activity polyether and ordinary flexible foam polyether. When preparing polyurethane foam from high-activity polymer polyols, a higher proportion of polymer polyol is used to improve load-bearing capacity, increasing the cost and density, thus failing to achieve a lightweight effect. During the foaming process, irregular cell structure causes the foam product to collapse, and in extreme formulations, it can lead to foam collapse. Chinese patent CN103923270B discloses a process for preparing high-activity polymer polyols, which involves preparing polymer polyols with different solid contents and then blending them, but it requires special additives and the synthesis of intermediates I and II, involving multiple steps. The method disclosed in CN114195957B innovatively uses a mixed solution of alcohol and water to dissolve azo compounds to solve the problem of initiator addition, but its applicability is narrow, and the decomposition products of azo compounds are either highly toxic or have a special odor, further limiting their use. There is a need to develop a high-performance preparation process for high-activity polymer polyols. Summary of the Invention

[0004] In view of this, the present invention provides a method for preparing a highly active polymer polyol. The product obtained by this method has dispersed particles in the polymer polyol with a multi-cavity structure, and the polyurethane foam prepared therefrom has the characteristics of good compressibility, good load-bearing capacity, and low density.

[0005] The present invention also provides the application of the aforementioned polymeric polyol in the preparation of polyurethane foam.

[0006] To achieve the objectives of this invention, the following technical solution is adopted in this application:

[0007] A method for preparing a highly active polymer polyol includes the following steps: in the presence of an initiator, a chain transfer agent, and an inert substance, a macromolecular monomer and an olefinic unsaturated monomer are polymerized in a polyether polyol, and then the polymer polyol is obtained by devolatilization treatment.

[0008] The polyether polyol described in this invention is a highly active polyether polyol, preferably a trifunctional polyether polyol with a hydroxyl value of 21-42 mgKOH / g, and more preferably a trifunctional polyether polyol with a hydroxyl value of 33.5-36.5 mgKOH / g.

[0009] The olefinic unsaturated monomers of the present invention include styrene, acrylonitrile, and functional monomers. The mass ratio of styrene to acrylonitrile is 10:90 to 90:10, more preferably 60:40 to 90:10; the mass ratio of the functional monomer to the total mass of styrene and acrylonitrile is 0.001 to 1:100, preferably 0.001 to 0.1:100.

[0010] The structure of the functional monomer described in this invention is shown below:

[0011]

[0012] In this context, R1 and R2 each represent a methyl or hydrogen atom, with R2 preferably being a methyl atom, and n is preferably an integer from 3 to 11. Because it is a polymer, the number-average molecular weight (Mn) is generally used to distinguish compounds with different properties. The Mn range of the above-mentioned functional monomers is 230 to 700. As an example, when Mn is 450, the compound is mostly a mixture of n=7 and 8.

[0013] In some preferred embodiments, the mass ratio of the olefinic unsaturated monomer to the polyether polyol is 0.1% to 200%, preferably 30% to 140%.

[0014] In this invention, the macromonomer is prepared by polymerization of a polyol with a monomer containing a double bond. Examples of monomers containing double bonds include maleic anhydride, fumaric acid, 1,1-dimethyl-m-isopropenylbenzyl isocyanate, ethyl isocyanate methacrylate, 2-buten-1,4-diol, 1-buten-3,4-diol, hydroxyethyl methacrylate, hydroxypropyl acrylate, methyl methacrylate, acrylic acid and methacrylic acid, methacryloyl chloride, glyceryl methacrylate, and allyl glycerol ether.

[0015] Macromonomers known in the art can be used, such as those described in patent CN96112759.7. The preparation of macromonomers is known in the art and will not be described further here.

[0016] In some preferred embodiments, when preparing the highly active polymeric polyol, the amount of the macromonomer added is 0.3% to 12% of the total mass of the polyether polyol and the olefinic unsaturated monomer, preferably 2% to 5%.

[0017] In some preferred embodiments, when preparing highly reactive polymeric polyols, the polymerization of olefinic unsaturated monomers is carried out in the presence of an initiator, preferably in an amount of 0.01-5 wt% of the total mass of the polyether polyol and the olefinic unsaturated monomers.

[0018] In some preferred embodiments, an initiator commonly used in the art may be used, such as one or more of peroxides and azo compounds; the peroxide is selected, for example, from one or more of benzoyl peroxide, lauroyl peroxide, tert-amyl peroxyisooctanoate, and tert-butyl peroxyisooctanoate, and the azo compound is selected, for example, from one or more of azobisisobutyronitrile (AIBN), azoisovaleritrile (AMBN), and dimethyl azobisisobutyrate (V601).

[0019] The specific process for preparing highly reactive polymer polyols can be carried out according to existing processes in the art, and is not particularly limited thereto. In some embodiments, the reaction temperature for preparing highly reactive polymer polyols can be 80–140°C, preferably 90–120°C; the reaction pressure (gauge pressure) can be 0–0.6 MPa, preferably 0.05–0.4 MPa.

[0020] In some preferred embodiments, when preparing highly active polymeric polyols, the polymerization of the olefinic unsaturated monomers is preferably carried out in the presence of a chain transfer agent, the amount of which is preferably 0.1-6 wt% of the total mass of the polyether polyol and the olefinic unsaturated monomers, more preferably 0.2-5 wt%.

[0021] In this invention, the chain transfer agent is selected from one or more of 1-butanol, 2-butanol, isopropanol, ethanol, and methanol, preferably 2-butanol and isopropanol.

[0022] In some preferred embodiments, other compounds may also be used in the preparation of highly reactive polymer polyols, such as compounds that promote mixing of the components, compounds that have a viscosity-reducing effect, and / or compounds that enable one or more of the components used to dissolve better in the reaction medium, wherein compounds that have a viscosity-reducing effect, such as toluene, dichloromethane, etc., promote better mixing of the components.

[0023] In this invention, the inert substance is a compound that does not participate in the polymerization reaction, and its boiling point is selected to be lower than that of at least one compound in the olefin unsaturated monomers, such as water, toluene, cyclohexane, etc., with water being preferred.

[0024] In this invention, the content of the inert substance accounts for 0.05-3% of the total mass of the entire reaction system, preferably 0.1-1.5%.

[0025] In this invention, the devolatilization process is divided into two steps, both at temperatures higher than the polymer's tg point. The first step maintains the reaction solution temperature at 110–130°C and the absolute pressure at 20–40 kPa; the second step maintains the reaction solution temperature at 130–150°C and the absolute pressure at 1–5 kPa.

[0026] In this invention, the devolatilization process refers to the conventional process of removing unreacted monomers, chain transfer agents, and inert substances from polymer polyols. It can be selected from common monomer removal unit operations such as flash evaporation, thin-film evaporation, ultragravity evaporation, and tower separation, and is not limited to these.

[0027] As a preferred option, the first step is to select flash evaporation, maintaining the temperature of the reaction liquid in the flash evaporator at 110-130℃, the absolute pressure at 20-40 kPa, and the average residence time at 2-3 hours; the second step is to select an external circulation falling film evaporator, maintaining the film temperature at 130-150℃, the absolute pressure at 1-5 kPa, and the average residence time at 0.5-1 hours.

[0028] In this invention, the preparation of the highly reactive polymer polyol is carried out in a batch or continuous operation, and the specific preparation process can be carried out using existing processes in the art. In some embodiments, after the preparation of the highly reactive polymer polyol is completed, a step of removing unreacted monomers and chain transfer agents is included. Common removal methods in the art can be used, such as distillation, flash evaporation, scraped plate or thin film evaporation, etc., chemical unit operations; often, the process is carried out under a certain vacuum and temperature.

[0029] The highly reactive polymeric polyols described in this invention are particularly suitable for use in the preparation of polyurethane foam materials (e.g., flexible polyurethane foam). Therefore, this invention also provides applications of the highly reactive polymeric polyols prepared by the described method for the preparation of polyurethane foams, especially flexible polyurethane foams.

[0030] This invention also provides a polyurethane foam material obtained by foaming a polyol blend and a polyisocyanate. The blend includes a highly reactive polymeric polyol obtained by the preparation method described in this invention.

[0031] In this invention, when preparing the polyurethane foam material, the polyisocyanate can be any well-known isocyanate permitted in the polyurethane manufacturing field (such as the isocyanate described in patent document US5011908A). Practically speaking, one or more of aliphatic polyisocyanates, cyclic aliphatic polyisocyanates, and aromatic polyisocyanates are preferred. Aliphatic polyisocyanates include, but are not limited to, 1,6-hexamethylene diisocyanate; cyclic aliphatic polyisocyanates include, but are not limited to, 1,6-cyclohexyl diisocyanate, 1-isocyanate-3,5,5-trimethyl-1,3-isocyanate-methylcyclohexane, 2,4- and 2,6-hexahydrotoluene-diisocyanate, 4,4'-, 2,2'- and 2,4'- One or more of the following: dicyclohexyl-methane diisocyanates and mixtures of their respective isomers; aromatic polyisocyanates, including but not limited to 2,4- and 2,6-toluene diisocyanates (TDI) and mixtures of their respective isomers, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates (MDI) and mixtures of their respective isomers, mixtures of 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanates and polyphenylmethylene polyisocyanates (PMDI); and one or more of the following modified polyisocyanates derived from these polyisocyanates and containing urethane, carbodiimide, urea, biuret, or isocyanurate groups.

[0032] In this invention, the equivalent ratio ((NCO groups / active hydrogen atoms) × 100) of the NCO groups in the polyisocyanate to the active hydrogen atoms in the polyol blend (which refers to a mixture of raw material components other than the polyisocyanate raw material), also known as the NCO index, can be appropriately adjusted based on the mechanical properties of polyurethane. For example, it is preferably 80 to 140, more preferably 85 to 120, and particularly preferably 95 to 115.

[0033] The specific preparation process of polyurethane foam can adopt the corresponding process known in the art, and the polyol composition also includes polyurethane catalyst, crosslinking agent, foaming agent, foam stabilizer, etc.

[0034] The polyurethane catalyst can be one or more of the following commonly used catalysts in the art: organometallic compounds such as stannous octoate, stannous oleate, dibutyltin dilaurate, dibutyltin acetate, and dibutyltin diacetate; and organic amine catalysts such as di(2,2′-dimethylamino)ethyl ether, trimethylamine, triethylamine, triethylenediamine, and dimethylethanolamine. Based on the weight of the polyol composition (which refers to the raw material components other than the polyisocyanate raw material), the amount of polyurethane catalyst used is typically about 0.1-3.0 wt%.

[0035] The crosslinking agent can be any commonly used crosslinking agent in the art, such as, but not limited to, glycerol and / or diethanolamine. If a crosslinking agent is used, the amount of crosslinking agent can be less than 3% (w / w), preferably 0.2-1.5% (w / w), based on the weight of the polyol composition.

[0036] The blowing agent includes, but is not limited to, one or more of the following: water, acetone, carbon dioxide, halogenated hydrocarbons, aliphatic alkanes, and cycloalkanes. As is well known in the art, water used as a blowing agent can produce carbon dioxide by reacting with isocyanates, which can be used as a blowing agent. Aliphatic alkanes and cycloalkanes have been developed as alternative blowing agents to CFC compounds. The blowing agent can be used alone or in mixtures of two or more thereof. Based on the weight of the polyol composition, the amount of blowing agent used is, for example, 0.1-20% (w / w).

[0037] The foam stabilizer is, for example, an organopolysiloxane surfactant, and the amount of foam stabilizer can be 0.4-1% (w / w) based on the weight of the polyol composition.

[0038] The polyol composition may further include polyether polyols. Preferably, based on the weight of the polymeric polyol in the polyol composition, the weight of the polyether polyol is 0.1-10 (w / w) of the weight of the polymeric polyol, more preferably 0.5-5 (w / w).

[0039] Depending on product requirements, 0.1-50% (w / w) of additives based on the weight of the polyol blend are often added, such as flame retardants, fillers, light stabilizers, antioxidants, etc., which will not be elaborated on here.

[0040] The present invention also provides an article comprising the polyurethane foam material described herein.

[0041] The technical solution provided by this invention has the following beneficial effects: In preparing the polymer polyol, this invention uses olefinic functional monomers, which are free-radical polymerized with acrylonitrile and styrene to form a solid insoluble in the polyether polyol. This solid serves as the dispersed phase particles suspended in the polyether polyol. Because the functional monomers have good hydrophilic properties, some of the chain transfer agent and water in the system, as well as some styrene and acrylonitrile, dissolve in the dispersed phase particles. Subsequently, during the high-temperature devolatilization process, styrene and acrylonitrile monomers partially polymerize upon heating. Low-boiling-point monomers (such as acrylonitrile) and isopropanol are removed in the first step, while water and high-boiling-point monomers (such as styrene) are removed in the second step. Because the removal temperature is above the Tg point but does not reach the molten state, the solid dispersed particles can still maintain a certain strength. This allows cavities or bubbles to form after water removal, and simultaneously, the outer surface of the solid dispersed particles becomes rough and uneven due to the escape of internal substances. When polyurethane foam is prepared from polymer polyols with this multi-porous structure, the internal temperature of the foam increases (e.g., to 180°C), causing the cavities within the suspended solid dispersion particles to expand due to heat. This allows for a further reduction in foam density with a limited amount of foaming agent. At the same time, the rough surface of the solid dispersion particles enhances their bonding ability with the polyurethane material, improving the compressibility and load-bearing capacity of the foam products. Attached Figure Description

[0042] Figure 1 CrossSection photograph of the polymer polyol in Example 1

[0043] Figure 2 TEM image of the polymer polyol in Example 1

[0044] Figure 3 SEM images of the polymer polyol in Example 1

[0045] Figure 4 CrossSection photograph of the polymer polyol in Example 2

[0046] Figure 5 TEM image of the polymer polyol in Example 2

[0047] Figure 6 SEM images of the polymer polyols in Example 2

[0048] Figure 7 SEM images of the polymer polyol in Example 3

[0049] Figure 8 SEM images of the polymer polyol in Example 3

[0050] Figure 9 CrossSection photograph of the polymer polyol in Comparative Example 1

[0051] Figure 10 TEM images of the polymer polyols in Comparative Example 1

[0052] Figure 11 SEM images of the polymer polyols in Comparative Example 1 Detailed Implementation

[0053] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0055] Main raw material sources

[0056] Macromonomer: A stabilizer polyether polyol reacts with maleic anhydride, followed by EO end-capping treatment, achieving a viscosity of 4000–4500 cp at 25℃. The stabilizer polyether polyol is a KOH-catalyzed high-resilience flexible foam polyether polyol prepared by reacting glycerol with propylene oxide and ethylene oxide, with a hydroxyl value of 28.5 mg KOH / g and an EO content of 12–16%.

[0057] Basic polyether polyols: High-primary-hydroxyl polyether polyols prepared by reacting glycerol with propylene oxide and then end-capping with ethylene oxide, with a molecular weight of 5000 and a primary hydroxyl content of 80-85%. (Wanhua Chemical Group Co., Ltd.) F3135.

[0058] Amyl peroxyisooctanoate: Initiator, Lanzhou Additives Factory.

[0059] Dimethyl azobisisobutyrate (V601): Initiator, Daqing Huaxing Chemical Co., Ltd.

[0060] Polyethylene glycol monomethyl ether methacrylate (MPEG-450): a mixture of number-average molecular weights Mn = 450, n = 7 and 8, R1 = R2 = -CH3, Beijing Innocare Technology Co., Ltd.

[0061] Polyethylene glycol monomethyl ether methacrylate (MPEG-300): a mixture of number-average molecular weights Mn = 300, n = 4 and 5, R1 = R2 = -CH3, Beijing Innocare Technology Co., Ltd.

[0062] Polyethylene glycol monomethyl ether methacrylate (MPEG-600): a mixture of number-average molecular weights Mn = 600, n = 10 and 11, R1 = R2 = -CH3, Beijing Innocare Technology Co., Ltd.

[0063] Styrene: Qilu Petrochemical.

[0064] Acrylonitrile: Lanzhou Petrochemical.

[0065] Isopropanol: Wanhua Chemical Group Co., Ltd.

[0066] Isobutanol (2-methyl-1-propanol): Shandong Xuchen Chemical Technology Co., Ltd.

[0067] 8001: Modified MDI (diphenylmethane diisocyanate), Wanhua Chemical Group Co., Ltd.

[0068] 8106: Organic bismuth catalyst, from a leading US chemical company.

[0069] B-8715LF2: Foam stabilizer, High Schmidt Chemical Co., Ltd.

[0070] A33: Polyurethane catalyst, a solution of 33% triethylenediamine and 67% dipropylene glycol, Gas Chemicals, USA.

[0071] A1: Polyurethane catalyst, a solution of 70% bis(dimethylaminoethyl) ether in dipropylene glycol, 33% triethylenediamine and 67% dipropylene glycol, Gas Chemicals, USA.

[0072] Pore-opening agents: Polyhydroxy compounds (also known as polyols) with a number average molecular weight of 2000–10000 and an average functionality of 2–4. Wanhua Chemical Group Co., Ltd. F5342.

[0073] Main testing methods

[0074] Scanning electron microscopy (SEM) characterization: Field emission scanning electron microscope, accelerating voltage not exceeding 5kV, model JSM-7900F, JEOL.

[0075] Transmission electron microscopy (SEM) characterization: Spectra 200 scanning transmission electron microscope, Thermo Fisher Scientific.

[0076] Cross-Section sample preparation, planar polishing mode using an argon ion polisher, Gatan 697.

[0077] Tear strength: Refer to GB / T 10808-2006 "Determination of tear strength of porous polymer elastic materials".

[0078] Tensile strength and elongation at break: Refer to GB / T 6344-2008 "Determination of tensile strength and elongation at break of flexible foam polymer materials".

[0079] Dry / wet compression deformation: Refer to GB / T 6669-2014 "Determination of compression set of flexible foam materials".

[0080] Example

[0081] Example 1

[0082] Industrial-scale polymer polyol preparation steps

[0083] 11.25 tons of styrene, 7.5 tons of acrylonitrile, 1.87 kg of polyethylene glycol monomethyl ether methacrylate (MPEG-450), and 14.17 tons of basic polyether polyol were completely mixed in a monomer storage tank. After cooling to 5°C, 90 kg of tert-amyl peroxide was added and mixed evenly as top material for later use.

[0084] 2.08 tons of macromolecular monomer stabilizer and 9.46 tons of basic polyether polyol were placed in a stirred tank reactor as the bottom material. After nitrogen purging, they were thoroughly mixed. The internal temperature was controlled at around 100℃. 1.47 tons of isopropanol and 0.22 tons of water were added and mixed evenly. Then, the top material was pumped in and the feeding time was maintained for 180 minutes. After the feeding was completed, the temperature was raised to 120℃ and maintained for 60 minutes for aging.

[0085] The reaction solution devolatilization system sequentially passed through a flash evaporator and a falling film evaporator. In the flash evaporator, the reaction solution temperature was maintained at 110–130°C, absolute pressure at 20–40 kPa, and average residence time at 2.5 h. In the falling film evaporator, the film temperature was maintained at 130–150°C, absolute pressure at 1–5 kPa, and average residence time at 1 h. The product after devolatilization was analyzed by SEM, TEM, and CrossSection as follows. Figure 1-3 As shown.

[0086] Example 2

[0087] 10.5 tons of styrene, 5.4 tons of acrylonitrile, 3.5 kg of polyethylene glycol monomethyl ether methacrylate (MPEG-300), and 14.175 tons of base polyether polyol were completely mixed in a monomer storage tank, cooled to 5°C, and then 187 kg of dimethyl azobisisobutyrate was added and mixed evenly before being used as top material.

[0088] 1.47 tons of macromolecular monomer stabilizer and 9.46 tons of base polyether polyol were placed in a stirred tank reactor as the bottom material. After nitrogen purging, they were thoroughly mixed. The internal temperature was controlled at around 100℃. 1.47 tons of isobutanol and 75 kg of water were added and mixed evenly. Then, the top material was pumped in and the feeding time was maintained for 180 minutes. After the feeding was completed, the temperature was raised to 120℃ and maintained for 60 minutes for aging.

[0089] The reaction solution devolatilization system sequentially passed through a flash evaporator and a falling film evaporator. In the flash evaporator, the reaction solution temperature was maintained at 110–130°C, absolute pressure at 20–40 kPa, and average residence time at 2.5 h. In the falling film evaporator, the film temperature was maintained at 130–150°C, absolute pressure at 1–5 kPa, and average residence time at 1 h. The product after devolatilization was analyzed by SEM, TEM, and CrossSection as follows. Figure 4-6 As shown.

[0090] Example 3

[0091] 9.5 kg of styrene, 9.5 kg of acrylonitrile, 1.0 g of polyethylene glycol monomethyl ether methacrylate (MPEG-600), and 20 kg of base polyether polyol were completely mixed in a monomer storage tank. After cooling to 5°C, 29 kg of tert-amyl peroxide was added and mixed evenly as top material for later use.

[0092] 1.1 kg of macromolecular monomer stabilizer and 6.08 kg of base polyether polyol were placed in a stirred tank reactor as the bottom material. After nitrogen purging, they were thoroughly mixed. The internal temperature was controlled at around 100°C. 1.2 kg of isopropanol and 0.3 kg of water were added and mixed evenly. Then, the top material was pumped in and the feeding time was maintained for 120 min. After the feeding was completed, the temperature was raised to 120°C and maintained for 60 min for aging.

[0093] The reaction solution devolatilization system sequentially passes through a flash evaporator and a falling film evaporator. In the flash evaporator, the reaction solution temperature is maintained at 110–130°C, absolute pressure at 20–40 kPa, and average residence time at 2.5 h. In the falling film evaporator, the film temperature is maintained at 130–150°C, absolute pressure at 1–5 kPa, and average residence time at 1 h. The product after devolatilization is analyzed using SEM (see attached image). Figure 7-8 As shown.

[0094] Comparative Example 1

[0095] 11.25 tons of styrene, 7.5 tons of acrylonitrile, and 14.17 tons of basic polyether polyol were completely mixed in a monomer storage tank, cooled to 5°C, and then 90 kg of tert-amyl peroxide was added and mixed evenly as top material for later use.

[0096] 2.08 tons of macromolecular monomer stabilizer and 9.46 tons of basic polyether polyol were placed in a stirred tank reactor as the bottom material. After nitrogen purging, they were thoroughly mixed. The internal temperature was controlled at around 100℃. 1.47 tons of isopropanol were added and mixed evenly. Then, the top material was pumped in and the feeding time was maintained for 180 minutes. After the feeding was completed, the temperature was raised to 120℃ and maintained for 60 minutes for aging.

[0097] The reaction solution devolatilization system sequentially passed through a flash evaporator and a falling film evaporator. In the flash evaporator, the reaction solution temperature was maintained at 110–130°C, absolute pressure at 20–40 kPa, and average residence time at 2.5 h. In the falling film evaporator, the film temperature was maintained at 130–150°C, absolute pressure at 1–5 kPa, and average residence time at 1 h. The product after devolatilization was analyzed by SEM, TEM, and CrossSection as follows. Figure 9-11 As shown:

[0098] Application examples

[0099] Preparation method of polyurethane foam:

[0100] Prepare the composite material according to the raw materials and weight parts shown in Table 1, and keep the composite material and isocyanate raw material at a constant temperature for 3 hours respectively. Then take the composite material and mix it with the isocyanate. Component 8001 is stirred and mixed in a mixer (3000 rpm) for 6 seconds. Then, the mixture is quickly poured into an open aluminum mold (300 mm long, 300 mm wide, and 50 mm thick) preheated to 60°C to allow it to foam. After 7 minutes, the foam is removed, yielding polyurethane foam.

[0101] Table 1. Formulation of Combined Materials

[0102] Foam Amount added / g Polymer polyols 60 Basic polyether polyols 40 Opening agent 3 diethanolamine 0.5 water 4 Opening agent Wanol F5342 3 A1 0.1 A33 0.3 B-8715LF2 0.5 Isocyanate index R 1.28 Reaction ratio (black and white materials) 80：100 Black and white material temperature 25℃

[0103] Application Examples 1-3 used the polymer polyols from Examples 1-3, with all other components remaining the same. The comparative application example used the polymer polyol prepared in Comparative Example 1. The foaming properties of the prepared polyurethane foam are shown in Tables 2-3 below:

[0104] Table 2 Polyurethane foaming properties

[0105]

[0106]

[0107] Electron microscopy images show that the polymer polyol particles prepared in this embodiment have high surface roughness and internal cavitation structures. In terms of polyurethane foam foaming, the foam prepared using the high-activity polyether in this embodiment has low density, but its mechanical properties are superior to those of existing high-activity polyethers, and its dry and wet compression deformation is better than that of the comparative embodiment (the smaller the data, the better).

[0108] It is readily understood that the above embodiments are merely illustrative examples for clear explanation and do not imply that the invention is limited thereto. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a highly active polymeric polyol, characterized in that, Includes the following steps: In the presence of an initiator, chain transfer agent, and inert substance, macromolecular monomers and olefinic unsaturated monomers are polymerized in polyether polyols, and then subjected to devolatilization treatment to obtain highly active polymer polyols. The olefinic unsaturated monomers include styrene, acrylonitrile, and functional monomers; The structure of the functional monomer is shown below: In this context, R1 and R2 each represent a methyl or hydrogen atom, with R2 preferably being a methyl atom, and n is preferably an integer from 3 to 11.

2. The preparation method according to claim 1, characterized in that, The Mn of the functional monomer is 230–600. Preferably, the polyether polyol is a highly active polyether polyol, preferably a trifunctional polyether polyol with a hydroxyl value of 21-42 mgKOH / g, and more preferably a trifunctional polyether polyol with a hydroxyl value of 33.5-36.5 mgKOH / g. Preferably, the mass ratio of styrene to acrylonitrile is 10:90 to 90:10, more preferably 60:40 to 90:10; the mass ratio of the functional monomer to the total mass of styrene and acrylonitrile is 0.001 to 1:100, preferably 0.001 to 0.1:

100. Preferably, the mass ratio of the olefinic unsaturated monomer to the polyether polyol is 0.1% to 200%, more preferably 30% to 140%.

3. The preparation method according to claim 1, characterized in that, The macromonomer is prepared by polymerization reaction of polyol and monomer containing double bond; Preferably, the amount of the macromonomer added is 0.3% to 12% of the total mass of the polyether polyol and the olefin unsaturated monomer, more preferably 2% to 5%.

4. The preparation method according to any one of claims 1-3, characterized in that, The polymerization of the olefinic unsaturated monomer is carried out in the presence of an initiator, wherein the amount of the initiator is 0.01-5 wt% of the total mass of the polyether polyol and the olefinic unsaturated monomer; Preferably, the initiator is one or more of peroxides and azo compounds; Preferably, the peroxide is selected from one or more of benzoyl peroxide, lauroyl peroxide, tert-amyl peroxide, and tert-butyl peroxide, and the azo compound is selected from one or more of azobisisobutyronitrile (AIBN), azoisovalerate (AMBN), and dimethyl azobisisobutyrate (V601).

5. The preparation method according to any one of claims 1-4, characterized in that, The reaction temperature can be 80–140℃, preferably 90–120℃; the reaction pressure (gauge pressure) can be 0–0.6 MPa, preferably 0.05–0.4 MPa. Preferably, the polymerization of the olefinic unsaturated monomer is carried out in the presence of a chain transfer agent, the amount of which is 0.1-6 wt% of the total mass of the polyether polyol and the olefinic unsaturated monomer, preferably 0.2-5 wt%. Preferably, the chain transfer agent is selected from one or more of 1-butanol, 2-butanol, isopropanol, ethanol, and methanol, with 2-butanol and isopropanol being more preferred; Preferably, the inert substance is a compound that does not participate in the polymerization reaction, and its boiling point is lower than that of at least one compound in the olefin unsaturated monomers, preferably water or one or more of toluene and cyclohexane, preferably water; Preferably, the inert substance accounts for 0.05-3% of the total mass of the entire reaction system, more preferably 0.1-1.5%; Preferably, the devolatilization process is divided into two steps, both with a treatment temperature higher than the polymer's tg point; the first step maintains the reaction solution temperature at 110-130°C and the absolute pressure at 20-40 kPa; the second step maintains the reaction solution temperature at 130-150°C and the absolute pressure at 1-5 kPa.

6. The application of the highly active polymeric polyol prepared by the preparation method according to any one of claims 1-5, wherein it is used to prepare polyurethane foam, especially flexible polyurethane foam.

7. A polyurethane foam material, obtained by foaming using a polyol blend and a polyisocyanate; wherein the blend comprises a polymer polyol obtained by the preparation method according to any one of claims 1-5.

8. The polyurethane foam material according to claim 7, wherein, The polyol composition further comprises a polyether polyol, preferably 0.1-10 (w / w) of the weight of the polymer polyol in the polyol composition, more preferably 0.5-5 (w / w).

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