Modified polysiloxane as well as preparation method and application thereof in polyester type polyurethane foam

Abstract

The invention discloses modified polysiloxane as well as a preparation method and application thereof in polyester type polyurethane foam, and relates to the technical field of polyester type polyurethane foam. The structural formula of the modified polysiloxane is as follows: # imgabs0 #, m is equal to 2-10, n is equal to 3-8, and p is equal to 1-7; the general formula of R1 is-CH2CH2CH2 (OC2H4) a (OC3H6) bOR5, a is equal to 5-11, b is equal to 0-3, and R5 is alkyl with 1-4 carbon atoms; r2 is an amphiphilic compound group; r < 3 > and R < 4 > are respectively alkyl with 1-4 carbon atoms, R < 1 > or R < 2 >. By simultaneously grafting the allyl polyether and containing remarkable hydrophilic and hydrophobic groups, the problem of mechanical property reduction caused by foam hole defects can be solved, so that the polyester type polyurethane foam material with uniform and fine foam hole distribution and excellent mechanical property is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of polyester-based polyurethane foams, and more particularly, to a modified polysiloxane, a preparation method thereof, and an application thereof in polyester-based polyurethane foams. Background Art

[0002] Polyester-based polyurethane foams have good resilience, solvent resistance, and heat resistance, remain stable in high-temperature and high-humidity environments, have high mechanical strength and flame retardancy, and can achieve characteristics such as light weight, high resilience, no deformation, and no collapse. They are applied to fields such as airline passenger seats, furniture, and construction that require high strength and weather resistance.

[0003] Polyurethane foam stabilizers are key additives in the production of polyurethane foams, which are related to the foam distribution, fineness, and open-cell condition of polyurethane foam products, thereby affecting performance indicators such as the air permeability, tensile strength, and compressive strength of polyurethane foams. Existing foam stabilizers applied to polyester-based foams have disadvantages such as large cell size, internal defects, and poor compatibility with polyester polyols during the polyurethane foaming process.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a modified polysiloxane, a preparation method thereof, an application of the modified polysiloxane in polyester-based polyurethane foams.

[0006] The present invention is implemented as follows:

[0007] In a first aspect, the present invention provides a modified polysiloxane, and its structural formula is as follows:

[0008]

[0009] wherein, m = 2 - 10, n = 3 - 8, p = 1 - 7;

[0010] The general formula of R1 is -CH 2 CH 2 CH 2 (OC 2 H 4 ) a (OC 3 H 6 ) b OR5, wherein a = 5 - 11, b = 0 - 3, and R5 is an alkyl group with 1 - 4 carbon atoms;

[0011] R2 is an amphiphilic compound group;

[0012] R3 and R4 are respectively an alkyl group with 1 - 4 carbon atoms, R1, or R2.

[0013] In an alternative embodiment, the amphiphilic compound group is a group formed by removing a hydrogen atom from a hydroxyl group in the amphiphilic compound, wherein the amphiphilic compound includes one or more of sorbitan monolaurate, sorbitan monooleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene monostearate, polyoxyethylene monolaurate, and cetyl polyoxyethylene ether.

[0014] Second, the present invention provides a method for preparing a modified polysiloxane, which includes: adding an allyl-terminated polyether, an amphiphilic compound, a low-hydrogen-content polysiloxane, and an amine auxiliary agent into a reaction kettle, heating to 80-100 °C in a dry nitrogen atmosphere, adding a catalyst, and holding the reaction at normal pressure for 2-6 h to obtain the modified polysiloxane.

[0015] In an alternative embodiment, the mass percentage ratio of the allyl-terminated polyether, the amphiphilic compound, and the low-hydrogen-content polysiloxane is 30-80 wt%: 5-50 wt%: 10-30 wt%.

[0016] In an alternative embodiment, the catalyst is a complex containing palladium, rhodium, or platinum;

[0017] Preferably, the catalyst is chloroplatinic acid or karsted catalyst;

[0018] Preferably, the dosage of the catalyst is 5-10 ppm.

[0019] In an alternative embodiment, the amine auxiliary agent is one or more of N,N-dimethylethanolamine, N,N-dibutylethanolamine, 3-dimethylpropylamine, and 2-butylaminoethanol;

[0020] Preferably, the dosage of the amine auxiliary agent is 100-1000 ppm.

[0021] In an alternative embodiment, the method for preparing the low-hydrogen-content polysiloxane includes:

[0022] Using octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, and hexamethyldisiloxane as raw materials, performing acid catalysis with an acid catalyst at 40-90 °C for 2-6 h, and preparing a side-chain hydrogen-containing polysiloxane after post-treatment;

[0023] Preferably, the mass percentage ratio of the octamethylcyclotetrasiloxane, the tetramethylcyclotetrasiloxane, and the hexamethyldisiloxane is 30-60 wt%: 30-60 wt%: 10-30 wt%;

[0024] Preferably, the acid catalyst includes acid-activated clay, sulfuric acid, and trifluorobenzenesulfonic acid, and the catalyst dosage is 0.1-1.5%;

[0025] Or,

[0026] Using octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, and 1,1,3,3-tetramethyldisiloxane as raw materials, acid catalysis is carried out with an acid catalyst at 40 - 90 °C for 2 - 6 h, and after post-treatment, a hydrogen-containing polysiloxane with hydrogen in the side chain and at the end is prepared.

[0027] Preferably, the mass percentage ratio of the octamethylcyclotetrasiloxane, the tetramethylcyclotetrasiloxane, and the 1,1,3,3-tetramethyldisiloxane is 30 - 60 wt%: 30 - 50 wt%: 10 - 20 wt%.

[0028] Preferably, the acid catalyst includes acid-activated clay, sulfuric acid, and trifluorobenzenesulfonic acid, and the catalyst dosage is 0.1 - 1.5%.

[0029] In a third aspect, the present invention provides the use of the modified polysiloxane as described in any one of the foregoing embodiments or the modified polysiloxane obtained by the preparation method of the modified polysiloxane as described in any one of the foregoing embodiments as an organosilicon surfactant in the preparation of polyester-based polyurethane foam.

[0030] In a fourth aspect, the present invention provides a polyester-based polyurethane foam, the components of which include the modified polysiloxane as described in any one of the foregoing embodiments or the modified polysiloxane obtained by the preparation method of the modified polysiloxane as described in any one of the foregoing embodiments.

[0031] In an alternative embodiment, the components further include a polyester polyol;

[0032] Preferably, the hydroxyl value of the polyester polyol is 30 - 80 mgKOH / g, and preferably the hydroxyl value is 45 - 65 mgKOH / g;

[0033] Preferably, the polyester polyol includes at least one of linear aliphatic polyester polyol, aromatic polyester polyol, branched aliphatic polyester polyol, and modified polyester polyol.

[0034] The present invention has the following beneficial effects:

[0035] The modified polysiloxane provided by the present invention contains both SiC and SiOC structures, and the modified R1, R2, R3, and R4 are grafted onto the side chains or both ends of the polysiloxane main chain. Among them, R1 is allyl polyether, R2 contains significant hydrophilic and hydrophobic groups. The grafted allyl polyether can improve the dispersibility of the modified polysiloxane and reduce its surface tension, and at the same time can improve its emulsification performance, excellent chemical stability and good lubrication performance. The grafted group containing amphiphilic compounds can make the polyester polyol have better compatibility and dispersibility, making the reaction more sufficient, thus solving the problem of the decline in mechanical properties caused by cell defects. Through the cooperation of these two, the modified polysiloxane can be applied to the preparation of polyester-based polyurethane foam, and can significantly improve the problems such as rough and disordered cells and the decline in mechanical properties caused by the fast reaction rate of polyester polyol, such as improving cell structure, tensile strength, tear strength and other problems, so as to obtain a polyester-based polyurethane foam material with uniform and delicate cell distribution and excellent mechanical properties. The preparation method of the modified polysiloxane provided by the present invention grafts allyl-terminated polyether and amphiphilic compounds at the hydrogen-containing positions (such as side chains or ends) of low-hydrogen polysiloxane to obtain the modified polysiloxane. The whole preparation method is simple and easy to operate. The prepared modified polysiloxane can be widely used as an organosilicon surfactant in the preparation of polyester-based polyurethane foam. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0037] Figure 1 Schematic diagram of the internal cell structure of the polyester-based polyurethane foam prepared in Example 1 and Example 2 of the present invention;

[0038] Figure 2 Schematic diagram of the internal cell structure of the polyester-based polyurethane foam prepared in Example 3 and Example 4 of the present invention;

[0039] Figure 3 Schematic diagram of the internal cell structure of the polyester-based polyurethane foam prepared in Example 5 and Example 6 of the present invention;

[0040] Figure 4 Schematic diagram of the outer tube structure of the polyester-based polyurethane foam prepared in Comparative Example 1 and Comparative Example 2 of the present invention;

[0041] Figure 5 Schematic diagram of the internal cell structure of the polyester-based polyurethane foam prepared in Comparative Example 3 and Comparative Example 4 of the present invention;

[0042] Figure 6 Schematic diagram of the internal cell structure of the polyester-based polyurethane foams prepared in Comparative Example 5 and Comparative Example 6 of the present invention. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For the reagents or instruments whose manufacturers are not indicated, they are all conventional products that can be obtained through commercial purchase.

[0044] The present invention provides a modified polysiloxane, and its structural formula is as follows:

[0045]

[0046] Wherein, m = 2 to 10, n = 3 to 8, p = 1 to 7;

[0047] The general formula of R1 is -CH 2 CH 2 CH 2 (OC 2 H 4 ) a (OC 3 H 6 ) b OR5, where a = 5 to 11, b = 0 to 3, and R5 is an alkyl group with 1 to 4 carbon atoms;

[0048] R2 is an amphiphilic compound group;

[0049] R3 and R4 are respectively an alkyl group with 1 to 4 carbon atoms, R1 or R2.

[0050] The amphiphilic compound group is a group formed by removing a hydrogen atom from a hydroxyl group in an amphiphilic compound. Among them, the amphiphilic compound includes one or more of sorbitan monolaurate, sorbitan monooleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene monostearate, polyoxyethylene monolaurate, and cetyl polyoxyethylene ether.

[0051] The modified polysiloxane provided by the present invention contains both SiC and SiOC structures, and the modified R1, R2, R3, and R4 are grafted onto the side chains or both ends of the polysiloxane main chain. Among them, R1 is allyl polyether, R2 contains significant hydrophilic and hydrophobic groups. The grafted allyl polyether can improve the dispersibility of the modified polysiloxane and reduce its surface tension, and at the same time can improve its emulsifying performance, excellent chemical stability and good lubricating performance. The grafted group containing amphiphilic compounds can make the polyester polyol have better compatibility and dispersibility, making the reaction more sufficient, thus solving the problem of mechanical property decline caused by cell defects. Through the cooperation of the two, the modified polysiloxane can be applied to the preparation of polyester-based polyurethane foams, and can significantly improve problems such as coarse and disordered cells and mechanical property decline caused by the fast reaction rate of polyester polyol, such as improving cell structure, tensile strength, tear strength, etc., so as to obtain polyester-based polyurethane foam materials with uniform and delicate cell distribution and excellent mechanical properties.

[0052] Furthermore, the present invention also provides a preparation method of a modified polysiloxane, which includes: adding allyl-terminated polyether, amphiphilic compound, low-hydrogen-content polysiloxane and amine auxiliary agent into a reaction kettle, heating to 80 - 100 °C in a dry nitrogen atmosphere, adding a catalyst, and keeping the temperature for reaction at normal pressure for 2 - 6 h to obtain the modified polysiloxane.

[0053] Among them, the mass percentage ratio of allyl-terminated polyether, amphiphilic compound and low-hydrogen-content polysiloxane is 30 - 80 wt%: 5 - 50 wt%: 10 - 30 wt%.

[0054] The catalyst is a complex containing palladium, rhodium or platinum; preferably, the catalyst is chloroplatinic acid or karsted catalyst; preferably, the dosage of the catalyst is 5 - 10 ppm.

[0055] The amine auxiliary agent is one or more of N,N-dimethylethanolamine, N,N-dibutylethanolamine, 3-dimethylpropylamine, 2-butylaminoethanol; preferably, the dosage of the amine auxiliary agent is 100 - 1000 ppm.

[0056] In the present invention, the low-hydrogen-content polysiloxane can be a conventional low-hydrogen-content polysiloxane, which can be obtained by commercial purchase or self-preparation, and the raw materials are adjusted according to the hydrogen content in the side chains or ends of the polysiloxane during the preparation process.

[0057] Specifically, the present invention provides the following two preparation methods of low-hydrogen-content polysiloxane:

[0058] The first method: Using octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, and hexamethyldisiloxane as raw materials, acid catalysis is carried out with an acid catalyst at 40 - 90 °C for 2 - 6 h, and after post-treatment, a hydrogen-containing polysiloxane with side chains is prepared; preferably, the mass percentage ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, and hexamethyldisiloxane is 30 - 60 wt%: 30 - 60 wt%: 10 - 30 wt%; preferably, the acid catalyst includes acid-activated clay, sulfuric acid, and trifluorobenzenesulfonic acid, and the catalyst dosage is 0.1 - 1.5%.

[0059] The second method: Using octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane, and 1,1,3,3-tetramethyldisiloxane as raw materials, acid catalysis is carried out with an acid catalyst at 40 - 90 °C for 2 - 6 h, and after post-treatment, a hydrogen-containing polysiloxane with side chains and ends is prepared; preferably, the mass percentage ratio of octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, and 1,1,3,3-tetramethyldisiloxane is 30 - 60 wt%: 30 - 50 wt%: 10 - 20 wt%; preferably, the acid catalyst includes acid-activated clay, sulfuric acid, and trifluorobenzenesulfonic acid, and the catalyst dosage is 0.1 - 1.5%.

[0060] The preparation method of the modified polysiloxane provided by the present invention obtains the modified polysiloxane by grafting allyl-terminated polyether and amphiphilic compounds at the hydrogen-containing positions (such as side chains or ends) of the low-hydrogen-content polysiloxane. The whole preparation method is simple and easy to operate. The prepared modified polysiloxane can be widely used as an organosilicon surfactant in the preparation of polyester-based polyurethane foams.

[0061] Furthermore, the present invention also provides a polyester-based polyurethane foam, the components of which include the above-mentioned modified polysiloxane or the modified polysiloxane prepared by the preparation method of the above-mentioned modified polysiloxane.

[0062] The components of the polyester-based polyurethane foam also include polyester polyol; preferably, the hydroxyl value of the polyester polyol is 30 - 80 mgKOH / g, and preferably the hydroxyl value is 45 - 65 mgKOH / g; preferably, the polyester polyol includes at least one of linear aliphatic polyester polyol, aromatic polyester polyol, branched aliphatic polyester polyol, and modified polyester polyol.

[0063] The features and properties of the present invention are further described in detail below in conjunction with examples.

[0064] Example 1

[0065] Add 71.0 g of hexamethyldisiloxane, 97.4 g of octamethylcyclotetrasiloxane, 131.6 g of tetramethylcyclotetrasiloxane, and 0.3 g of trifluorobenzenesulfonic acid into the reactor, stir at 60 - 65 °C for 3 h, and after post-treatment, obtain an average structure of MD 3D H 5 Hydrogen-containing polysiloxane of M. Where M is (CH 3 ) 3 SiO-, D is -Si(CH 3 ) 2 O-, D H is -SiH(CH 3 )O-.

[0066] 124.8 g of allyl methyl-terminated polyether A (average molecular weight of 300, ethylene oxide group), 110.7 g of sorbitan monolaurate, 64.5 g of hydrogen-containing polysiloxane MD 3 D H 5 M and 200 ppm (calculated based on the total amount of materials, the same below) of N,N-dibutylethanolamine were mixed in a reactor, heated to 85 - 90 °C in a dry nitrogen atmosphere, and stirred for 10 min. 10 ppm of Pt (ethanol solution of chloroplatinic acid) was added, and the reaction was carried out at a constant temperature for 5 h to obtain an amber transparent viscous liquid.

[0067] Example 2

[0068] 51.8 g of hexamethyldisiloxane, 94.7 g of octamethylcyclotetrasiloxane, and 153.5 g of tetramethylcyclotetrasiloxane were added to a reactor, 4 g of acidic clay was added, and the mixture was stirred at 70 - 75 °C for 3 h. After post-treatment, a hydrogen-containing polysiloxane with an average structure of MD 4 D H 8 M was obtained.

[0069] 211.2 g of allyl methyl-terminated polyether A, 29.7 g of sorbitan monolaurate, 59.1 g of hydrogen-containing polysiloxane MD 4 D H 8 M and 200 ppm of N,N-dibutylethanolamine were mixed in a reactor, heated to 95 - 100 °C in a dry nitrogen atmosphere, and stirred for 10 min. 8 ppm of Pt (karsted) was added. The reaction was carried out at a constant temperature for 4 h to obtain an amber transparent viscous liquid.

[0070] Example 3

[0071] 42.9 g of hexamethyldisiloxane, 98.1 g of octamethylcyclotetrasiloxane, and 159.0 g of tetramethylcyclotetrasiloxane were added to a reactor, 0.3 g of trifluorobenzenesulfonic acid was added, and the mixture was stirred at 60 - 65 °C for 3 h. After post-treatment, a hydrogen-containing polysiloxane with an average structure of MD 5 D H 10 M was obtained.

[0072] 110.7 g of allyl methyl-capped polyether B (with an average molecular weight of 350 and ethylene oxide groups), 142.5 g of sorbitan monooleate, 46.8 g of hydrogen-containing polysiloxane MD 3 D H 5 M and 100 ppm of N,N-dimethylethanolamine were mixed in a reactor, heated to 85 - 90 °C in a dry nitrogen atmosphere, and stirred for 10 min. 10 ppm of Pt (ethanol solution of chloroplatinic acid) was added. The reaction was carried out under insulation for 5 h to obtain an amber transparent viscous liquid.

[0073] Example 4

[0074] 38.0 g of 1,1,3,3-tetramethyldisiloxane, 125.9 g of octamethylcyclotetrasiloxane, and 136.1 g of tetramethylcyclotetrasiloxane were added to a reactor. 0.3 g of trifluorobenzenesulfonic acid was added, and the mixture was stirred at 60 - 65 °C for 3 h. After post-treatment, a hydrogen-containing polysiloxane with an average structure of M H D 6 D H 8 M H was obtained. Where M H is (CH 3 ) 2 SiHO-.

[0075] 141.6 g of allyl methyl-capped polyether B, 108.0 g of sorbitan monooleate, 50.4 g of hydrogen-containing polysiloxane M H D 6 D H 8 M H and 100 ppm of N,N-dimethylethanolamine were mixed in a reactor, heated to 90 - 95 °C in a dry nitrogen atmosphere, and stirred for 10 min. 9 ppm of Pt (Karsted catalyst) was added. The reaction was carried out under insulation for 3 h to obtain an amber transparent viscous liquid.

[0076] Example 5

[0077] 49.6 g of hexamethyldisiloxane, 158.6 g of octamethylcyclotetrasiloxane, and 91.8 g of tetramethylcyclotetrasiloxane were added to a reactor. 3 g of acidic clay was added, and the mixture was stirred at 75 - 85 °C for 3 h. After post-treatment, a hydrogen-containing polysiloxane with an average structure of MD 7 D H 5 M was obtained.

[0078] 125.4 g of allyl methyl-capped polyether C (with an average molecular weight of 400, containing 90% by weight of ethylene oxide groups and 10% by weight of propylene oxide groups), 123.0 g of sorbitan monolaurate polyoxyethylene ether, 51.6 g of hydrogen-containing polysiloxane MD 7 D H 5 M and 100 ppm of N,N-dimethylethanolamine were mixed in a reactor, heated to 85 - 90 °C in a dry nitrogen atmosphere, and stirred for 10 min. Then 10 ppm of Pt (ethanol solution of chloroplatinic acid) was added. The reaction was carried out at a constant temperature for 6 h to obtain an amber transparent viscous liquid.

[0079] Example 6

[0080] 44.8 g of 1,1,3,3-tetramethyldisiloxane, 163.5 g of octamethylcyclotetrasiloxane, and 99.5 g of tetramethylcyclotetrasiloxane were added to a reactor. 0.4 g of trifluorobenzenesulfonic acid was added, and the mixture was stirred at 60 - 65 °C for 3 h. After post-treatment, a hydrogen-containing polysiloxane with an average structure of M H D 8 D H 6 M H was obtained.

[0081] 134.1 g of allyl methyl-capped polyether C, 123.6 g of sorbitan monooleate polyoxyethylene ether, 42.3 g of hydrogen-containing polysiloxane M H D 8 D H 6 M H and 150 ppm of N,N-dibutylethanolamine were mixed in a reactor, heated to 85 - 90 °C in a dry nitrogen atmosphere, and stirred for 10 min. Then 10 ppm of Pt (karsted catalyst) was added. The reaction was carried out at a constant temperature for 3 h to obtain an amber transparent viscous liquid.

[0082] Comparative Example 1

[0083] 71.0 g of hexamethyldisiloxane, 97.4 g of octamethylcyclotetrasiloxane, 131.6 g of tetramethylcyclotetrasiloxane, and 0.3 g of trifluorobenzenesulfonic acid were added to a reactor. The mixture was stirred at 60 - 65 °C for 3 h. After post-treatment, a hydrogen-containing polysiloxane with an average structure of MD 3 D H 5 M was obtained.

[0084] 234.0 g of allyl methyl-capped polyether A, 66.0 g of hydrogen-containing polysiloxane MD 3 D H 5M and 100 ppm of N,N-dimethylethanolamine were mixed in a reactor, heated to 95 - 100 °C in a dry nitrogen atmosphere, stirred for 10 min, and 8 ppm of Pt (ethanol solution of chloroplatinic acid) was added. After holding the temperature for reaction for 4 h, an amber transparent viscous liquid was obtained.

[0085] Comparative Example 2

[0086] 31.8 g of hexamethyldisiloxane, 174.1 g of octamethylcyclotetrasiloxane, 94.1 g of tetramethylcyclotetrasiloxane, and 3 g of acidic clay were added to a reactor, stirred at 60 - 65 °C for 3 h, and after post-treatment, a hydrogen-containing polysiloxane with an average structure of MD 12 D H 8 M was obtained.

[0087] 210.0 g of allyl methyl-terminated polyether A and 90.0 g of hydrogen-containing polysiloxane MD 12 D H 8 M and 100 ppm of N,N-dimethylethanolamine were mixed in a reactor, heated to 95 - 100 °C in a dry nitrogen atmosphere, stirred for 10 min, and 8 ppm of Pt (ethanol solution of chloroplatinic acid) was added. After holding the temperature for reaction for 4 h, an amber transparent viscous liquid was obtained.

[0088] Comparative Example 3

[0089] 22.9 g of 1,1,3,3-tetramethyldisiloxane, 209.2 g of octamethylcyclotetrasiloxane, 67.9 g of tetramethylcyclotetrasiloxane, and 0.4 g of trifluorobenzenesulfonic acid were added to a reactor, stirred at 60 - 65 °C for 3 h,

[0090] and after post-treatment, a hydrogen-containing polysiloxane with an average structure of M H D 20 D H 8 M H was obtained.

[0091] 87.0 g of allyl methyl-terminated polyether B, 155.4 g of allyl methyl-terminated polyether D (with an average molecular weight of 1000, containing 60 wt% of ethylene oxide groups and 40 wt% of propylene oxide groups), and 57.6 g of hydrogen-containing polysiloxane M H D 20 D H 8 M HMix with 100 ppm of N,N - dimethylethanolamine in a reactor, heat to 85 - 90 °C in a dry nitrogen atmosphere, and stir for 10 min. Add 10 ppm of Pt (ethanol solution of chloroplatinic acid). Keep the temperature for reaction for 5 h to obtain an amber transparent viscous liquid.

[0092] Comparative Example 4

[0093] Add 26.0 g of hexamethyldisiloxane, 215.7 g of octamethylcyclotetrasiloxane, 58.3 g of tetramethylcyclotetrasiloxane, and 0.3 g of trifluorobenzenesulfonic acid into a reactor, stir at 60 - 65 °C for 3 h, and after post - treatment, obtain a hydrogen - containing polysiloxane with an average structure of MD 15 D H 5 M.

[0094] Mix 80.7 g of allyl - methyl - terminated polyether B, 144.3 g of allyl - methyl - terminated polyether D, 75.0 g of hydrogen - containing polysiloxane MD 15 D H 5 M and 150 ppm of N,N - dibutylethanolamine in a reactor, heat to 95 - 100 °C in a dry nitrogen atmosphere, and stir for 10 min. Add 8 ppm of Pt (ethanol solution of chloroplatinic acid). Keep the temperature for reaction for 4 h to obtain an amber transparent viscous liquid.

[0095] Comparative Example 5

[0096] Add 25.0 g of hexamethyldisiloxane, 228.6 g of octamethylcyclotetrasiloxane, 46.3 g of tetramethylcyclotetrasiloxane, and 4 g of acidic clay into a reactor, stir at 60 - 65 °C for 3 h, and after post - treatment, obtain a hydrogen - containing polysiloxane with an average structure of MD 20 D H 5 M.

[0097] Mix 132.9 g of allyl - methyl - terminated polyether E (with an average molecular weight of 1500, containing 60 wt% of ethylene oxide groups and 40 wt% of propylene oxide groups), 79.8 g of allyl - methyl - terminated polyether A, 87.3 g of hydrogen - containing polysiloxane MD 20 D H 5 M and 200 ppm of N,N - dibutylethanolamine in a reactor, heat to 90 - 95 °C in a dry nitrogen atmosphere, and stir for 10 min. Add 8 ppm of Pt (ethanol solution of chloroplatinic acid). Keep the temperature for reaction for 4 h to obtain an amber transparent viscous liquid.

[0098] Comparative Example 6

[0099] 44.8 g of 1,1,3,3 - tetramethyldisiloxane, 163.5 g of octamethylcyclotetrasiloxane, and 99.5 g of tetramethylcyclotetrasiloxane were added to a reactor. 0.4 g of trifluorobenzenesulfonic acid was added, and the mixture was stirred at 60 - 65 °C for 3 h. After post - treatment, a hydrogen - containing polysiloxane with an average structure of M H D 8 D H 6 M H was obtained.

[0100] 161.1 g of allyl - methyl - terminated polyether E, 96.6 g of allyl - methyl - terminated polyether A, 42.3 g of hydrogen - containing polysiloxane M H D 8 D H 6 M H and 150 ppm of N,N - dimethylethanolamine were mixed in a reactor, heated to 85 - 90 °C in a dry nitrogen atmosphere, and stirred for 10 min. 10 ppm of Pt (ethanol solution of chloroplatinic acid) was added. The reaction was carried out at a constant temperature for 5 h to obtain an amber - colored transparent viscous liquid.

[0101] The polyester - type polyurethane foams were prepared for the examples and comparative examples, and the specific formulations are shown in Table 1.

[0102] Table 1. Formulation for preparing polyester - type polyurethane foam

[0103] Raw material Ratio (wt%) Polyester polyol 100 Water 3.0 Catalyst 1.0 TDI80 / 20 22 TDI65 / 35 23 Organosilicon surfactant 0.9

[0104] All polyester foams were prepared with the same formulation as above. The main difference between the examples was that the surfactant of one example was replaced with another surfactant.

[0105] The foams were evaluated using the performance tests described below:

[0106] Tensile strength: The sample preparation and test method refer to GB / T 6344 - 2008 "Flexible cellular polymeric materials - Determination of tensile strength and elongation at break".

[0107] Tear strength: The sample preparation and test method refer to GB / T 10808 - 2006 "Determination of tear strength of high - polymer porous elastic materials".

[0108] The polyester - type polyurethane foams were prepared according to the standard, with only the silicone surfactant changed. The prepared foams were tested and compared, and the results are shown in Table 2 below. The appearance and internal cell structure of the foams are shown in Figure 1 - Figure 6 .

[0109] Table 2. Mechanical properties of the prepared polyester - type polyurethane foams

[0110]

[0111]

[0112] Figure 1 - Figure 6 It is shown that the polyester-based polyurethane foams prepared using Comparative Examples 1-6 of the modified polysiloxane have foam collapse or obvious internal defects. For Comparative Example 1, Comparative Example 2, Comparative Example 5, and Comparative Example 6, it was impossible to take foam samples for testing. For Comparative Example 3 and Comparative Example 4, samples were taken for testing by avoiding the internal defects of the foam. Among them, in Comparative Example 1, only polyether A capped with allyl methyl was grafted. In Comparative Example 2, not only polyether A capped with allyl methyl was grafted. At the same time, the value of m in the hydrogen-containing polysiloxane was 12, which was greater than the scope of the present application. At this time, neither Comparative Example 1 nor Comparative Example 2 could prepare polyester-based polyurethane foams, and there was a situation of foam collapse. Both Comparative Example 3 and Comparative Example 4 were grafted with two kinds of allyl methyl-capped polyethers B and D. At the same time, the values of m in the hydrogen-containing polysiloxane were 20 and 15, respectively, both of which were greater than the scope of the present application. At this time, although polyester-based polyurethane foams could be prepared, their tensile strength, elongation at break, and tear strength were all significantly lower than those of the examples of the present application, and the cell structure was coarser with obvious internal defects. Although Comparative Example 5 and Comparative Example 6 were also grafted with two kinds of allyl methyl-capped polyethers, the grafted ones were polyether A and E. At this time, the cell structure was coarser with obvious internal defects, and it was impossible to take samples for detection. In addition, although polyethers were grafted in Comparative Examples 1-6, there were significant differences in the effects due to the differences between the grafted polyethers and the amphiphilic compounds. The modified polysiloxane of the present invention exhibits obvious excellent properties in terms of cell structure, tensile strength, elongation at break, and tear strength.

[0113] In summary, the modified polysiloxane provided by the present invention contains both SiC and SiOC structures, and the modified R1 and R2 are grafted onto the side chains or both ends of the polysiloxane main chain. Among them, R1 is allyl polyether, and R2 contains significant hydrophilic and hydrophobic groups. The grafted allyl polyether can improve the dispersibility of the modified polysiloxane and reduce its surface tension, and at the same time can improve its emulsifying performance, excellent chemical stability and good lubricating performance. The grafted group containing amphiphilic compounds can make the polyester polyol have better compatibility and dispersibility, making the reaction more sufficient, thus solving the problem of the decrease in mechanical properties caused by cell defects. Through the cooperation of the two, the modified polysiloxane can be applied to the preparation of polyester polyurethane foam, and can significantly improve the problems such as coarse and disordered cells and the decrease in mechanical properties caused by the fast reaction rate of polyester polyol, such as improving cell structure, tensile strength, tear strength, etc., so as to obtain a polyester polyurethane foam material with uniform and delicate cell distribution and excellent mechanical properties. The preparation method of the modified polysiloxane provided by the present invention obtains the modified polysiloxane by grafting allyl polyether and amphiphilic compounds at the hydrogen-containing positions (such as side chains or ends) of low-hydrogen polysiloxane. The whole preparation method is simple and easy to operate. The prepared modified polysiloxane can be widely used as an organosilicon surfactant in the preparation of polyester polyurethane foam.

[0114] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A modified polysiloxane, characterized in that: Its structural formula is as follows: Wherein, m=2-10, n=3-8, p=1-7; The general formula of R1 is -CH2CH2CH2(OC2H4) a (OC3H6) b OR5, wherein a=5-11, b=0-3, and R5 is an alkyl group of 1-4 carbon atoms; R2 is an amphiphilic compound group; R3 and R4 are respectively an alkyl group having 1 to 4 carbon atoms, R1 or R2.

2. The modified polysiloxane according to claim 1, characterized in that The amphiphilic compound group is a group formed by removing a hydrogen atom from a hydroxyl group in the amphiphilic compound, wherein the amphiphilic compound includes one or more of sorbitan monolaurate, sorbitan monooleate, sorbitan monolaurate polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, monostearate polyoxyethylene ether, monolaurate polyoxyethylene ether and hexadecyl polyoxyethylene ether.

3. A method for preparing a modified polysiloxane, characterized in that: It includes: Add terminal allyl polyether, amphiphilic compound, low hydrogen polysiloxane and amine auxiliary agent into a reaction kettle, heat to 80-100°C in a dry nitrogen atmosphere, add catalyst, and keep warm for reaction at normal pressure for 2-6 hours to obtain modified polysiloxane.

4. The method for preparing modified polysiloxane according to claim 3, characterized in that: The mass percentage ratio of the terminal allyl polyether, the amphiphilic compound and the low hydrogen-containing polysiloxane is 30-80wt%: 5-50wt%: 10-30wt%.

5. The method for preparing modified polysiloxane according to claim 3, characterized in that: The catalyst is a complex containing palladium, rhodium or platinum; Preferably, the catalyst is chloroplatinic acid or a karsted catalyst; Preferably, the catalyst is used in an amount of 5 to 10 ppm.

6. The method for preparing modified polysiloxane according to claim 3, characterized in that: The amine auxiliary agent is one or more of N,N-dimethylethanolamine, N,N-dibutylethanolamine, 3-dimethylpropylamine, and 2-butylaminoethanol; Preferably, the dosage of the amine auxiliary agent is 100-1000 ppm.

7. The method for preparing modified polysiloxane according to claim 3, characterized in that: The preparation method of the low hydrogen-containing polysiloxane comprises: Octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane and hexamethyldisiloxane are used as raw materials, acid-catalyzed at 40 to 90° C. for 2 to 6 hours, and side-chain hydrogen-containing polysiloxane is prepared after post-treatment; Preferably, the mass percentage ratio of the octamethylcyclotetrasiloxane, the tetramethylcyclotetrasiloxane and the hexamethyldisiloxane is 30-60wt%: 30-60wt%: 10-30wt%; Preferably, the acid catalyst comprises acid clay, sulfuric acid, trifluorobenzenesulfonic acid, and the amount of the catalyst is 0.1 to 1.5%; or, Octamethylcyclotetrasiloxane, tetramethyltetrahydrocyclotetrasiloxane and 1,1,3,3-tetramethyldisiloxane are used as raw materials, acid-catalyzed at 40-90° C. for 2-6 hours, and side chain and terminal hydrogen-containing polysiloxane is prepared after post-treatment; Preferably, the mass percentage ratio of the octamethylcyclotetrasiloxane, the tetramethylcyclotetrasiloxane and the 1,1,3,3-tetramethyldisiloxane is 30-60wt%: 30-50wt%: 10-20wt%; Preferably, the acid catalyst comprises acid clay, sulfuric acid, trifluorobenzenesulfonic acid, and the amount of the catalyst is 0.1-1.5%.

8. Use of the modified polysiloxane according to any one of claims 1 to 2 or the modified polysiloxane prepared by the method for preparing the modified polysiloxane according to any one of claims 3 to 7 as an organosilicon surfactant in the preparation of polyester polyurethane foam.

9. A polyester polyurethane foam, characterized in that: The components thereof include the modified polysiloxane as described in any one of claims 1 to 2 or the modified polysiloxane prepared by the preparation method of the modified polysiloxane as described in any one of claims 3 to 7.

10. The polyester polyurethane foam according to claim 9, characterized in that Its components also include polyester polyols; Preferably, the polyester polyol has a hydroxyl value of 30 to 80 mgKOH / g, and preferably a hydroxyl value of 45 to 65 mgKOH / g; Preferably, the polyester polyol includes at least one of linear aliphatic polyester polyol, aromatic polyester polyol, branched aliphatic polyester polyol and modified polyester polyol.

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