Composite silicone foam and method of making same, silicone composite fibrous blanket flame retardant material and method of making same

Abstract

The present application relates to the technical field of composite materials, and discloses a composite silicone foam and a preparation method thereof, and a silicone composite fiber cloth flame-retardant material and a preparation method thereof.The method comprises the following steps: mixing polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups in the presence of a polymerization inhibitor I to obtain material I; mixing the material I with phosphorus-boron additives, nano-enhanced fillers and polydimethylsiloxane containing vinyl groups II to obtain material II; the phosphorus-boron additives are a combination of phosphorus-containing substances and boron-containing substances; and mixing the material II with a catalyst III to obtain the composite silicone foam.The method provided by the present application solves the problem of insufficient adhesion between the PDMS surface and the functional coating due to the hydrophobicity of the PDMS, and the composite silicone foam prepared by the method is applied to the preparation of a silicone composite fiber cloth flame-retardant material, and the obtained silicone composite fiber cloth flame-retardant material has excellent high-temperature resistance, thermal shock resistance and heat insulation effect.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, specifically to composite silicone foam and its preparation method, and silicone composite fiber cloth flame retardant material and its preparation method. Background Technology

[0002] Thermal runaway in lithium-ion batteries is typically triggered by factors such as overcharging and internal short circuits, ultimately resulting in the violent release of high-temperature, high-pressure gas jets. The core temperature of these jets can reach 800-1200°C, with ejection velocities exceeding 200 m / s. These jets not only rapidly increase the temperature of adjacent battery cells and damage the overall battery structure, but can also trigger secondary combustion reactions, significantly accelerating the propagation of thermal runaway. Therefore, in-depth analysis of the evolution mechanism of lithium-ion battery thermal runaway and the development of novel materials that combine efficient thermal insulation with structural protection have become core issues urgently needing breakthroughs in the field of energy storage system safety.

[0003] In the field of nanoporous materials research, polydimethylsiloxane (PDMS) foam, with its unique molecular chain structure and excellent physicochemical stability, has become an important candidate system to replace traditional aerogel materials. However, existing PDMS-based foam materials still have significant technical bottlenecks: pure organosilicon foam has poor temperature resistance and is prone to thermal failure at high temperatures, which may exacerbate local heat accumulation; although PDMS foam modified with inorganic materials can improve temperature resistance, its impact resistance and thermal shock stability are significantly reduced; and nano-aerogel composite modified systems face the dual problems of insufficient gas barrier properties and low interfacial bonding strength. None of the above materials can simultaneously meet the synergistic requirements of thermal insulation performance, impact resistance, and structural stability in thermal runaway protection scenarios. In addition, the inherent hydrophobicity of the PDMS foam surface leads to significantly insufficient interfacial adhesion between it and functional coatings, making it prone to interlayer delamination failure, which further limits its application in complex protection scenarios. It is worth noting that inorganic fiber cloth, as a commonly used intermediate support layer, has advantages such as excellent impact resistance, easy composite molding, and controllable cost, and can be adapted to complex scenarios in multiple dimensions. However, single fiber cloth materials still cannot solve the comprehensive protection problem under the coupling effect of "high temperature and high pressure" during thermal runaway.

[0004] CN102532505A discloses a method for preparing polycarbonate-polydimethylsiloxane nanocomposites. The method includes: adding polydimethylsiloxane, diphenyl carbonate, and magnesium chloride to a reaction vessel; under inert gas protection; sequentially stirring and heating to carry out a molten transesterification reaction; cooling the product after the reaction; then adding bisphenol A; under inert gas protection; stirring and heating to carry out a polycondensation reaction; adding nanomaterials during the polycondensation reaction to obtain the final product; then adding the product to dichloromethane; washing with anhydrous ethanol; filtering; and drying the filter cake to obtain the polycarbonate-polydimethylsiloxane nanocomposites. This composite is an environmentally friendly flame-retardant polycarbonate that can reduce the maximum heat release rate of polycarbonate. However, this preparation method yields flame-retardant materials with poor consistency and unstable actual flame-retardant effects. Furthermore, the preparation process is relatively complex, and the use of the toxic solvent dichloromethane is environmentally unfriendly. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing polydimethylsiloxane foams, such as insufficient interfacial adhesion between the foam and functional coatings, insufficient resistance to high-pressure gas breakdown, and insufficient fire resistance.

[0006] To achieve the above objectives, a first aspect of the present invention provides a method for preparing composite organosilicon foam, the method comprising: (1) In the presence of a polymerization inhibitor, polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups are mixed to obtain material I; (2) The material I is mixed with phosphorus and boron additives, nano-reinforced fillers and vinyl-containing polydimethylsiloxane to obtain material II; the phosphorus and boron additives are a combination of phosphorus-containing and boron-containing substances; (3) The material II is mixed with the catalyst III to obtain the composite organosilicon foam; The weight ratio of the siloxane combination, the phosphorus-boron additive, and the nano-reinforcing filler is 1:0.03-0.1:0.03-1; the siloxane combination is a combination of the polydimethylsiloxane containing Si-H bonds, the polydimethylsiloxane containing hydroxyl groups, and the polydimethylsiloxane containing vinyl groups.

[0007] A second aspect of the present invention provides a composite organosilicon foam prepared by the method described in the first aspect.

[0008] A third aspect of the present invention provides a method for preparing an organosilicon composite fiber cloth flame retardant material, the method comprising: (S1) The modified composite silicone foam and the modified fiber cloth are laminated to obtain the laminated system; The modified composite organosilicon foam is obtained by modifying composite organosilicon foam with silane coupling agent I, and the composite organosilicon foam is the composite organosilicon foam described in the second aspect; The modified fiber cloth is obtained by modifying fiber cloth with silane coupling agent II. The fiber cloth is selected from at least one of inorganic fiber cloth, organic synthetic fiber cloth and natural plant fiber cloth. The silane coupling agent II may be the same as or different from the silane coupling agent I. (S2) Under a preset pressure, the composite system is cured to obtain the organosilicon composite fiber cloth flame retardant material.

[0009] A fourth aspect of the present invention provides an organosilicon composite fiber cloth flame retardant material prepared by the method described in the third aspect.

[0010] Through the above technical solution, the present invention has at least the following advantages over the prior art: (1) The method for preparing composite organosilicon foam provided by the present invention significantly slows down the thermal decomposition process inside the material through the dual effects of physical barrier and chemical inhibition; and the introduced nano-reinforcing material can improve the mechanical properties of the foam matrix and form a dense ceramic layer through pyrolysis reaction under high temperature conditions, and finally obtain a multi-component synergistically reinforced composite organosilicon foam with excellent high temperature resistance, thermal shock resistance and excellent heat insulation effect.

[0011] (2) The composite silicone foam provided by this invention solves the problem of insufficient adhesion between PDMS and functional coatings due to the hydrophobicity of the PDMS surface; at the same time, it has multi-dimensional protection functions in high-temperature combustion pyrolysis, and the three-layer structure interface is stable, avoiding interlayer delamination. Among them, at the gas phase level, the pyrolysis products dilute the combustible gas to weaken combustion; the internal mechanical properties (such as compressive strength and flexural strength) of the matrix are strong, and after pyrolysis, a dense ceramic layer is formed at the reduction site, which blocks heat transfer by means of low thermal conductivity; in terms of structural protection, the intermediate layer gives the material excellent longitudinal tensile strength, and can resist the impact of high temperature and high pressure gas and prevent gas from piercing the matrix, providing reliable protection for adjacent batteries. Therefore, the composite silicone foam has excellent comprehensive properties such as flame retardancy, fire prevention, heat insulation, puncture resistance and smoke suppression. After high-temperature combustion, the surface ceramic layer and the intermediate layer still maintain good heat insulation and impact resistance, expanding the application scenarios of extreme high temperature.

[0012] (3) The method for preparing composite organosilicon foam provided by the present invention has a simple production process, is conducive to large-scale production and has controllable cost. Attached Figure Description

[0013] Figure 1 This is a graph showing the heat release rate of the organosilicon composite fiber cloth flame retardant material and untreated pure foam in Examples 1 to 4 of the present invention. Figure 2This is a graph showing the total smoke production curves of the organosilicon composite fiber cloth flame retardant material and untreated pure foam in Examples 1 to 4 of the present invention; Figure 3 This is a graph showing the average specific extinction area of ​​the organosilicon composite fiber cloth flame retardant material of Examples 1 to 4 of the present invention compared with that of untreated pure foam; Figure 4 This is a graph showing the oxygen index and UL-94 rating data of the organosilicon composite fiber cloth flame retardant material of Examples 1 to 4 of the present invention and untreated pure foam; Figure 5 These are thermogravimetric analysis (TGA) test curves of the organosilicon composite fiber cloth flame retardant material of Examples 1 to 4 of the present invention and untreated pure foam. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] In this invention, the "polydimethylsiloxane containing Si-H bonds" refers to a polydimethylsiloxane containing "Si-H bond" functional groups, but the polydimethylsiloxane does not contain "hydroxyl" functional groups or "vinyl" functional groups. The term "hydroxyl-containing polydimethylsiloxane" refers to a polydimethylsiloxane containing a "hydroxyl" functional group, but the polydimethylsiloxane does not contain a "Si-H bond" functional group or a "vinyl" functional group. The term "vinyl-containing polydimethylsiloxane" refers to polydimethylsiloxane containing a "vinyl" functional group, but without either a "Si-H bond" functional group or a "hydroxyl" functional group.

[0016] As previously described, a first aspect of the present invention provides a method for preparing composite organosilicon foam, the method comprising: (1) In the presence of a polymerization inhibitor, polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups are mixed to obtain material I; (2) The material I is mixed with phosphorus and boron additives, nano-reinforced fillers and vinyl-containing polydimethylsiloxane to obtain material II; the phosphorus and boron additives are a combination of phosphorus-containing and boron-containing substances; (3) The material II is mixed with the catalyst III to obtain the composite organosilicon foam; The weight ratio of the siloxane combination, the phosphorus-boron additive, and the nano-reinforcing filler is 1:0.03-0.1:0.03-1; the siloxane combination is a combination of the polydimethylsiloxane containing Si-H bonds, the polydimethylsiloxane containing hydroxyl groups, and the polydimethylsiloxane containing vinyl groups.

[0017] Preferably, in step (1), the polymerization inhibitor is selected from at least one of siloxane compounds, cycloalkane compounds, phenolic scavengers, coordination inhibitors and thiol chain transfer agents.

[0018] More preferably, the siloxane compound is selected from at least one of 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-1,3,5,7,2,4,6,8-tetraoxatetrasiloxane, 2,4,6-trimethyl-2,4,6-trivinyl-1,3,5-trioxatrisiloxane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and 1-ethynyl-1,1,3,3-tetramethyldisiloxane.

[0019] More preferably, the cycloalkane compound is 2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloalkane.

[0020] More preferably, the phenol scavenging agent is hydroquinone and / or p-tert-butylcatechol.

[0021] More preferably, the coordination inhibitor is selected from at least one of tetramethylethylenediamine, 2,6-di-tert-butylpyridine, and triphenylphosphine.

[0022] More preferably, the thiol chain transfer agent is dodecathiol.

[0023] In a preferred embodiment, in step (1), the Si-H bond-containing polydimethylsiloxane is selected from at least one of hydrogen-terminated polydimethylsiloxane, hydrofluoric polydimethylsiloxane, and hydrophenyl polydimethylsiloxane, preferably at least one of hydrogen-terminated polydimethylsiloxane and / or hydrofluoric polydimethylsiloxane.

[0024] Preferably, the Si-H content in the polydimethylsiloxane containing Si-H bonds is 1-5 wt%.

[0025] Preferably, the hydroxyl-containing polydimethylsiloxane is selected from at least one of hydroxyl polydimethylsiloxane, monohydroxyl-terminated polydimethylsiloxane, dihydroxyl-terminated diphenyl polydimethylsiloxane, dihydroxyl-terminated diphenyl polydimethylsiloxane, dihydroxypropyl-terminated fluoropolydimethylsiloxane, silanol-hydroxyphenyl silicone oil, and hydroxyl-fluorinated polydimethylsiloxane, and is more preferably at least one of hydroxyl polydimethylsiloxane, monohydroxyl-terminated polydimethylsiloxane, dihydroxyl-terminated diphenyl polydimethylsiloxane, and dihydroxyl-terminated diphenyl polydimethylsiloxane.

[0026] In a preferred embodiment, in step (2), the weight ratio of the phosphorus-containing substance to the boron-containing substance in the phosphorus-boron additive is 1-3:1. Under this preferred embodiment, the technical solution provided by the present invention can obtain an organosilicon composite fiber cloth flame-retardant material with superior high-temperature resistance, thermal shock resistance, and thermal insulation effect.

[0027] Preferably, in step (2), the phosphorus-containing substance is selected from at least one of ammonium polyphosphate, melamine polyphosphate, zirconium phosphate, diethyl ethyl phosphonate, hexachlorocyclotriphosphononitrile and triphenyl phosphate, and is preferably ammonium polyphosphate.

[0028] Preferably, the boron-containing substance is selected from at least one of zinc borate, boron nitride, phenyl borate, 2-methyl-1,3,2-benzodioxoborane and sodium perborate tetrahydrate, and preferably zinc borate.

[0029] In a preferred embodiment, the nano-reinforcing filler is selected from at least two of aramid fibers, silica aerogel, alumina aerogel, silica-alumina composite aerogel, kaolin, montmorillonite, talc, sepiolite, halloysite, zirconium oxide, hollow glass microspheres, and silicon carbide.

[0030] More preferably, the nano-reinforcing filler is a combination of silica aerogel and kaolin in a weight ratio of 0.05-0.25:1. The inventors have found that, under this preferred condition, the technical solution provided by the present invention can yield an organosilicon composite fiber cloth flame-retardant material with superior high-temperature resistance, thermal shock resistance, and thermal insulation effect.

[0031] Preferably, the vinyl-containing polydimethylsiloxane is selected from at least one of vinyl polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, vinyl-terminated diphenyl-dimethyl copolymer siloxane, monovinyl-terminated polydimethylsiloxane, and vinyl-terminated fluorinated polydimethylsiloxane, and more preferably at least one of vinyl polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, vinyl-terminated diphenyl-dimethyl copolymer siloxane, and monovinyl-terminated polydimethylsiloxane.

[0032] Preferably, in the siloxane combination, the weight ratio of the Si-H bond-containing polydimethylsiloxane, the hydroxyl-containing polydimethylsiloxane, and the vinyl-containing polydimethylsiloxane is 1:4-10:3-8. Under this preferred embodiment, the technical solution provided by the present invention can obtain an organosilicon composite fiber cloth flame-retardant material with superior high-temperature resistance, thermal shock resistance, and thermal insulation effect.

[0033] In a preferred embodiment, the kinematic viscosity of the hydroxyl-containing polydimethylsiloxane and the vinyl-containing polydimethylsiloxane at 25°C is independently 500-20000 cSt.

[0034] Preferably, the mixing time for mixing I and mixing time for mixing II are each 2-5 minutes independently.

[0035] In a preferred embodiment, in step (3), the catalyst is a platinum-based catalyst and / or an organotin catalyst.

[0036] More preferably, the platinum-based catalyst is hexachloroplatinic acid and / or a Karstedt catalyst.

[0037] More preferably, the organotin catalyst is selected from at least one of dibutyltin dilaurate, dimethyltin dilaurate, dioctyltin dilaurate, stannous octoate, dibutyltin diacetate, dimethyltin diacetate, dioctyltin diacetate, diacetylacetonate dibutyltin, dodecylthiodibutyltin, dodecylthiodimethyltin, dodecylthiodioctyltin, dioctyltin dioctanoate, dioctyltin dioctanoate, dioctyltin oxide, and dibutyltin oxide.

[0038] Preferably, in step (3), the mixing time of mixing III is 30-40 seconds.

[0039] Preferably, the weight ratio of the siloxane combination, the polymerization inhibitor, and the catalyst is 1:0.005-0.015:0.005-0.02.

[0040] The method for preparing composite organosilicon foam described in this invention can also involve post-processing methods in the fields of settling and drying. For example, the material obtained from the mixing process III is sequentially settling and drying; the settling time is 10-100 min; the drying temperature is 30-100℃, and the drying time is 1-24 h. Further details are omitted here, and those skilled in the art should not construe this as a limitation of the invention.

[0041] As previously stated, a second aspect of the present invention provides a composite organosilicon foam prepared by the method described in the first aspect.

[0042] As previously described, a third aspect of the present invention provides a method for preparing an organosilicon composite fiber cloth flame-retardant material, the method comprising: (S1) The modified composite silicone foam and the modified fiber cloth are laminated to obtain the laminated system; The modified composite organosilicon foam is obtained by modifying composite organosilicon foam with silane coupling agent I, and the composite organosilicon foam is the composite organosilicon foam described in the second aspect; The modified fiber cloth is obtained by modifying fiber cloth with silane coupling agent II. The fiber cloth is selected from at least one of inorganic fiber cloth, organic synthetic fiber cloth and natural plant fiber cloth. The silane coupling agent II may be the same as or different from the silane coupling agent I. (S2) Under a preset pressure, the composite system is cured to obtain the organosilicon composite fiber cloth flame retardant material.

[0043] Preferably, in step (S1), the silane coupling agent I and the silane coupling agent II are each independently selected from at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (abbreviated as KH-792), γ-aminopropyltriethoxysilane (abbreviated as A-1100), N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane (abbreviated as A-1120), γ-aminopropyltrimethoxysilane (abbreviated as KBM-903), γ-(2,3-epoxypropoxy)propyltrimethoxysilane (abbreviated as KH-560), KH550 and γ-(2,3-epoxypropoxy)propyltrimethoxysilane (abbreviated as A-187), preferably KH550.

[0044] More preferably, in step (S1), the inorganic fiber cloth is selected from at least one of glass fiber cloth, carbon fiber cloth, basalt fiber cloth and ceramic fiber cloth, and is preferably glass fiber cloth.

[0045] More preferably, in step (S1), the organic synthetic fiber cloth is aramid fiber cloth and / or polyester fiber cloth.

[0046] More preferably, in step (S1), the natural plant fiber cloth is flax fiber cloth.

[0047] In a preferred embodiment, in step (S1), the modification method is selected from one of immersion, coating, and spraying.

[0048] According to a preferred embodiment, the modified composite silicone foam is prepared by a method comprising the following steps: The silane coupling agent I was diluted with ethanol, and the diluted silane coupling agent I was coated on one side of the surface of the composite organosilicon foam. After drying, the modified composite organosilicon foam was obtained.

[0049] Preferably, relative to 1cm 2 The composite organosilicon foam contains silane coupling agent I in an amount of 0.02-0.06 g.

[0050] Preferably, the weight ratio of the silane coupling agent I to the ethanol is 1:19-49.

[0051] Preferably, the drying conditions I include: a temperature of 40-100℃ and a time of 1-5h.

[0052] According to a preferred embodiment, the modified fiber cloth is prepared by a method comprising the following steps: The silane coupling agent II was diluted with ethanol, and the diluted silane coupling agent II was coated on the upper and lower surfaces of the fiber cloth. After drying II, the modified fiber cloth was obtained.

[0053] It should be noted that in the above method, the plane containing the long side of the fiber cloth is taken as the horizontal reference plane, the side away from the ground is called the upper surface, and the side facing the ground is called the lower surface.

[0054] In the preferred case, relative to 1cm 2 The amount of silane coupling agent II used in the fiber cloth is 0.01-0.04g.

[0055] Preferably, the weight ratio of the silane coupling agent II to the ethanol is 1:19-49.

[0056] Preferably, the drying conditions II include: a temperature of 30-90°C and a time of 0.5-6 hours.

[0057] In a preferred embodiment, in step (S1), the thickness ratio of the modified composite silicone foam to the modified fiber cloth is 1:0.02-0.08.

[0058] Preferably, in step (S1), the area of ​​the modified composite silicone foam is 15-35 cm². 2 The thickness is 0.1-0.4cm.

[0059] It should be noted that the "area" mentioned above refers to the area of ​​the upper or lower surface of the modified composite silicone foam; wherein, with the plane containing the long side of the modified composite silicone foam as the horizontal reference plane, the side away from the ground is called the upper surface, and the side facing the ground is called the lower surface.

[0060] Preferably, in step (S2), the pressure device for applying the preset pressure is selected from one of the following: a manual screw press, a digital display manual press, a manual hydraulic pressure pump, clamps, lever-type pressure clamps, spring-type pressure clamps, a manual small hydraulic jack, and a universal testing machine.

[0061] Preferably, in step (S2), the preset pressure is 0.1-0.5 MPa.

[0062] In a preferred embodiment, in step (S2), the curing conditions include: a temperature of 30-100°C, a time of 1-7 hours, and 1-2 cycles.

[0063] As previously described, the fourth aspect of the present invention provides an organosilicon composite fiber cloth flame retardant material prepared by the method described in the third aspect.

[0064] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, the instruments, medicines and reagents used are all conventional commercially available products.

[0065] Polydimethylsiloxanes containing Si-H bonds: Hydrogen-terminated polydimethylsiloxane-1: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 70900-21-9; the Si-H content is 1 wt%. Hydrogen-terminated polydimethylsiloxane-2: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 70900-21-9; the Si-H content is 2wt%; Hydrofluoric polydimethylsiloxane-1: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 63148-56-1; the Si-H content is 3wt%; Hydrofluoric polydimethylsiloxane-2: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 63148-56-1; the Si-H content is 4wt%.

[0066] Hydroxyl-containing polydimethylsiloxane: Hydroxyhydroxy polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 70131-67-8; kinematic viscosity at 25°C is 5000 cSt; Single-terminated monohydroxyphenyl polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 102782-86-5; kinematic viscosity at 25℃ is 5000 cSt; Dihydroxyalkyl monoterminated polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 218131-11-4; kinematic viscosity at 25°C is 5000 cSt; Dihydroxy-terminated diphenyl polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 68951-93-9; kinematic viscosity at 25℃ is 5000 cSt.

[0067] Vinyl-containing polydimethylsiloxanes: Vinyl polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 53529-60-5; kinematic viscosity at 25°C is 10000 cSt; Vinyl-terminated polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 68083-19-2; kinematic viscosity at 25°C is 10000 cSt; Vinyl-terminated diphenyl-dimethyl copolysiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 68951-96-2; kinematic viscosity at 25°C is 10000 cSt; Monovinyl-terminated polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 68952-00-1; kinematic viscosity at 25°C is 10000 cSt.

[0068] Fiber cloth: Fiberglass cloth: purchased from China Jushi Co., Ltd.; Aramid fiber cloth: purchased from China Jushi Co., Ltd.; Linen fiber cloth: purchased from China Jushi Co., Ltd.

[0069] In the following examples, room temperature refers to a temperature of 23±2℃.

[0070] The following preparation examples illustrate the preparation method of the composite organosilicon foam provided by the present invention. Preparation Example 1 (1) At room temperature, in the presence of a polymerization inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloane), polydimethylsiloxane containing Si-H bonds (4g) and polydimethylsiloxane containing hydroxyl groups are mixed (I) for 3 min to obtain material I; (2) Material I is mixed with phosphorus and boron additives (a combination of ammonium polyphosphate and zinc borate), nano-reinforced filler (a combination of silica aerogel and kaolin), and vinyl-containing polydimethylsiloxane (for 5 min) to obtain material II; (3) Mix material II with catalyst (Karstedt catalyst) for 30 seconds, let stand for 20 minutes, and then dry in an oven at 60°C for 1 hour to obtain composite organosilicon foam.

[0071] Preparation Examples 2 to 4 were carried out using a method similar to that of Preparation Example 1, except that the types and amounts of raw materials were different, as listed in Table 1.

[0072] Table 1

[0073] Note: The phosphorus and boron additives are a combination of ammonium polyphosphate and zinc borate; the siloxane combination is a combination of polydimethylsiloxane containing Si-H bonds, polydimethylsiloxane containing hydroxyl groups, and polydimethylsiloxane containing vinyl groups.

[0074] Preparation Example 5 The preparation was carried out in a similar manner to that of Example 1, except that the total amount of the siloxane combination was kept constant, and the weight ratio of the polydimethylsiloxane containing Si-H bonds, the polydimethylsiloxane containing hydroxyl groups, and the polydimethylsiloxane containing vinyl groups was adjusted to 1:12:2. Everything else is the same, resulting in composite organosilicon foam Z-5.

[0075] Preparation Example 6 The preparation was carried out in a similar manner to that of Example 1, except that the amount of phosphorus and boron additives was kept constant, and the weight ratio of ammonium polyphosphate to zinc borate was adjusted to 5:1. Everything else is the same, resulting in composite organosilicon foam Z-6.

[0076] Comparative preparation 1 The preparation was carried out in a similar manner to that of Example 1, except that the amount of siloxane combination was kept constant, and the amount of phosphorus boron additive and nano-reinforcing filler was adjusted so that the weight ratio of siloxane combination, phosphorus boron additive and nano-reinforcing filler was 1:0.2:1.2. Everything else is the same, resulting in composite organosilicon foam DZ-1.

[0077] Comparative Preparation Example 2 (1) Keep the types and amounts of raw materials unchanged, and choose to add all raw materials at once. Specifically: At room temperature, in the presence of a polymerization inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloane) and a catalyst (Karstedt catalyst), polydimethylsiloxane containing Si-H bonds (4g), polydimethylsiloxane containing hydroxyl groups, phosphorus and boron additives (a combination of ammonium polyphosphate and zinc borate), vinyl-containing polydimethylsiloxane, and nano-reinforcing fillers (a combination of silica aerogel and kaolin) were contact-mixed (for 8 min), then allowed to stand for 20 min, and then dried in a 60℃ oven for 1 h to obtain composite organosilicon foam DZ-2.

[0078] Comparative preparation example 3 (1) At room temperature, in the presence of a polymerization inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloane), a portion of polydimethylsiloxane containing Si-H bonds (4g) and polydimethylsiloxane containing hydroxyl groups were mixed (I) for 3 min to obtain material I; (2) Material I is mixed with phosphorus and boron additives (a combination of ammonium polyphosphate and zinc borate), nano-reinforced filler (a combination of silica aerogel and kaolin), and the remaining part of polydimethylsiloxane containing Si-H bonds (for 5 min) to obtain material II; (3) Mix material II with catalyst (Karstedt catalyst) for 30 seconds, let stand for 20 minutes, and then dry in an oven at 60°C for 1 hour to obtain composite organosilicon foam DZ-3.

[0079] The weight ratio of silica aerogel to kaolin is 0.2:1; The weight ratio of the siloxane combination (a combination of polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups), the phosphorus-boron additive (a combination of ammonium polyphosphate and zinc borate) and the nano-reinforcing filler is 1:0.03:0.03. The weight ratio of polydimethylsiloxane containing Si-H bonds, polydimethylsiloxane containing hydroxyl groups, and the remaining polydimethylsiloxane containing vinyl groups is 1:4:4. The weight ratio of ammonium polyphosphate to zinc borate is 1:1; The weight ratio of the siloxane combination (a combination of polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups) to the polymerization inhibitor and catalyst is 1:0.005:0.008.

[0080] Comparative preparation example 4 The preparation was carried out in a similar manner to that of Example 1, except that an equal weight of black phosphorus was used to replace zinc borate; Everything else is the same, resulting in composite organosilicon foam DZ-4.

[0081] The following examples illustrate the preparation method of the organosilicon composite fiber cloth flame retardant material provided by the present invention. Example 1 (S1) Dilute silane coupling agent I (KH550) with ethanol, and then coat one side of the diluted KH550 onto an area of ​​25 cm². 2 A composite silicone foam Z-1 with a thickness of 0.19 cm was formed and then dried (at 60℃ for 1 hour) to obtain an area of ​​25 cm². 2A modified composite silicone foam with a thickness of 0.2 cm; wherein the weight ratio of KH550 and ethanol is 1:19; relative to 1 cm 2 The composite silicone foam Z-1 uses 0.04g of KH550.

[0082] The silane coupling agent II (KH550) was diluted with ethanol, and the diluted silane coupling agent II was coated on an area of ​​25 cm². 2 The upper and lower surfaces of a 0.019cm thick fiberglass cloth were dried (at 60℃ for 1 hour) to obtain an area of ​​25cm². 2 A modified fiber cloth with a thickness of 0.02 cm; wherein the weight ratio of KH550 to ethanol is 1:19; relative to an area of ​​1 cm² 2 The amount of KH550 used in the glass fiber cloth is 0.024g.

[0083] Repeat the above preparation process of modified composite silicone foam to obtain two portions of modified composite silicone foam. Then, stack them in the order of modified composite silicone foam, modified glass fiber cloth, and modified composite silicone foam, with the side of the modified composite silicone foam coated with KH550 in contact with the modified fiber cloth to obtain the stacked system.

[0084] (S2) Clamp the composite system with quick clamps and apply a preset pressure (0.5MPa) to make the modified composite silicone foam and modified fiber cloth in the composite system adhere tightly. Maintain this pressure state and transfer it to the drying equipment for curing treatment (temperature 80℃, time 2h) to achieve coupling agent-mediated interfacial bonding and system curing. Finally, repeat the above operation process twice to obtain silicone composite fiber cloth flame retardant material S-1.

[0085] Example 2 The procedure was carried out using a method similar to that in Example 1, except that composite silicone foam Z-1 was replaced with composite silicone foam Z-2 of equal mass, and glass fiber cloth of equal thickness was replaced with aramid fiber cloth. Everything else is the same, resulting in the organosilicon composite fiber cloth flame retardant material S-2.

[0086] Example 3 The procedure was carried out using a method similar to that in Example 1, except that composite silicone foam Z-1 was replaced with composite silicone foam Z-3 of equal mass, and glass fiber cloth of equal thickness was replaced with flax fiber cloth. Everything else is the same, resulting in the silicone composite fiber cloth flame retardant material S-3.

[0087] Example 4 to Comparative Example 4 The same method as in Example 1 was used, except that composite silicone foam Z-1 was replaced with composite silicone foam Z-4, composite silicone foam Z-5, composite silicone foam Z-6, composite silicone foam DZ-1, composite silicone foam DZ-2, composite silicone foam DZ-3, and composite silicone foam DZ-4 of equal mass. All other materials are the same, and the following flame-retardant materials were obtained: S-4, S-5, S-6, DS-1, DS-2, DS-3, and DS-4, respectively.

[0088] Test case The performance of the organosilicon composite fiber fabric flame retardant materials prepared in the examples and comparative examples was tested, including: heat release rate, total smoke production, average specific extinction area, oxygen index (LOl), UL-94 rating, and thermogravimetric analysis. The test results were compared with those of untreated pure polydimethylsiloxane foam (hereinafter referred to as "pure foam"). The test results are shown in Table 2.

[0089] The preparation method of pure foam is as follows: First, 8g of hydrogen-terminated polydimethylsiloxane-1, 40g of hydroxyl polydimethylsiloxane, and a polymerization inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloane) were placed in a reaction vessel and mechanically mixed at 900 rpm for 3 min. Then, 40g of vinyl polydimethylsiloxane was added to the mixture, and the stirring speed was increased to 1200 rpm for 5 min to form a prepolymer. Next, 0.4g of Karstedt catalyst (mass concentration of 5000 ppm) was injected into the prepolymer, and rapid stirring was performed for 30 s to complete catalytic activation. The activated system was transferred to a pre-designed mold and allowed to stand at room temperature for 15 min to build a three-dimensional network structure. Finally, the foamed sample was placed in a 60℃ constant temperature oven for 4 h for heat treatment to promote complete cross-linking and curing of the organosilicon network.

[0090] The relevant testing methods are as follows: Heat release rate, total smoke production and average specific extinction area: all were tested using a cone calorimeter, in accordance with ISO 5660, at 35 kW.

[0091] Oxygen Index (LOI): The Limited Oxygen Index (LOI) was analyzed using a JF-3 oxygen index instrument according to ISO 4589-2-1996, with a sample size of 100 mm × 10 mm × 10 mm.

[0092] UL-94 rating: Tested using a 5402H-V flammability tester according to ASTM D 3801 test standard, with a sample size of 130mm × 13mm × 10mm.

[0093] Thermogravimetric analysis: Tests were performed using a TGA Q500 thermogravimetric analyzer under a nitrogen atmosphere at a heating rate of 10℃·min. -1 .

[0094] Table 2

[0095] Note: "HB" indicates no level.

[0096] The present invention exemplarily in Figure 1 The document provides heat release rate curves of the organosilicon composite fiber cloth flame retardant material and untreated pure foam from Examples 1 to 4; Figure 1 It can be seen that the peak heat release rates of samples S-1 to S-4 are between 80-120 kW / m³. 2 The heat release rate of the untreated pure foam sample was between 120-220 kW / m³. 2 This demonstrates that the organosilicon composite fiber cloth flame-retardant material prepared by this invention exhibits excellent flame-retardant properties.

[0097] The present invention exemplarily in Figure 2 The document provides total smoke production curves for the organosilicon composite fiber cloth flame-retardant materials of Examples 1 to 4 and untreated pure foam; Figure 2 It can be seen that the total smoke production of samples S-1 to S-4 ranges from 1.2 to 6 m³. 2 Between, the total smoke production of the untreated pure foam sample exceeded 9m³. 2 This demonstrates that the organosilicon composite fiber cloth flame retardant material prepared by this invention exhibits excellent smoke suppression performance.

[0098] The present invention exemplarily in Figure 3 The document provides average specific extinction area curves of the organosilicon composite fiber cloth flame-retardant materials of Examples 1 to 4 and untreated pure foam; Figure 3 It can be seen that the average specific extinction area of ​​samples S-1 to S-4 ranges from 145 to 215 m². 2 The average specific extinction area of ​​the untreated pure foam sample was close to 325 m² / kg. 2 / kg. This demonstrates that the organosilicon composite fiber cloth flame retardant material prepared by this invention exhibits good high-temperature resistance.

[0099] The present invention exemplarily in Figure 4The document provides oxygen index and UL-94 rating data for the silicone composite fiber fabric flame-retardant materials of Examples 1 to 4 and untreated pure foam; Figure 4 It can be seen that samples S-1 to S-4 all reached the UL-94 V0 level, and their oxygen index all exceeded 36%, while the untreated pure foam sample did not have a level in the UL-94 test, and its oxygen index did not exceed 20%. This indicates that the organosilicon composite fiber cloth flame retardant material prepared by this invention exhibits good flame retardant properties.

[0100] The present invention exemplarily in Figure 5 Thermogravimetric analysis (TGA) curves of the organosilicon composite fiber fabric flame retardant material and untreated pure foam from Examples 1 to 4 are provided; Figure 5 It can be seen that the remaining weight of samples S-1 to S-4 is between 62% and 72%, while the remaining weight of the untreated pure foam sample is close to 58%. This indicates that the organosilicon composite fiber cloth flame retardant material prepared by this invention exhibits good high-temperature resistance.

[0101] The results above show that the method for preparing composite organosilicon foam provided by the present invention produces composite organosilicon foam with significantly improved hydrophilicity of the foam surface and significantly enhanced mechanical properties of the polydimethylsiloxane foam matrix. Furthermore, through the dual effects of physical barrier and chemical inhibition, it greatly slows down the thermal decomposition process inside the material and can also form a dense ceramic layer through pyrolysis reaction under high temperature conditions.

[0102] The composite silicone foam provided by this invention is used in the preparation of silicone composite fiber cloth flame retardant materials. The adhesion between the fiber cloth and the polydimethylsiloxane foam is greatly improved, solving the problem of insufficient adhesion to functional coatings caused by the hydrophobicity of the PDMS surface. Therefore, the silicone composite fiber cloth flame retardant material provided by this invention has excellent high-temperature resistance, thermal shock resistance, and thermal insulation effect, and can be applied in the fields of flame retardant insulation and thermal protection of energy storage batteries.

[0103] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing composite organosilicon foam, characterized in that, The method includes: (1) In the presence of a polymerization inhibitor, polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups are mixed to obtain material I; (2) The material I is mixed with phosphorus and boron additives, nano-reinforced fillers and vinyl-containing polydimethylsiloxane to obtain material II; the phosphorus and boron additives are a combination of phosphorus-containing and boron-containing substances; (3) The material II is mixed with the catalyst III to obtain the composite organosilicon foam; The weight ratio of the siloxane combination, the phosphorus-boron additive, and the nano-reinforcing filler is 1:0.03-0.1:0.03-1; the siloxane combination is a combination of the polydimethylsiloxane containing Si-H bonds, the polydimethylsiloxane containing hydroxyl groups, and the polydimethylsiloxane containing vinyl groups.

2. The method according to claim 1, wherein, In the siloxane combination, the weight ratio of the Si-H bond-containing polydimethylsiloxane, the hydroxyl-containing polydimethylsiloxane, and the vinyl-containing polydimethylsiloxane is 1:4-10:3-8. And / or, in the phosphorus-boron additive, the weight ratio of the phosphorus-containing substance to the boron-containing substance is 1-3:1; And / or, the weight ratio of the siloxane combination to the polymerization inhibitor and the catalyst is 1:0.005-0.015:0.005-0.

02.

3. The method according to claim 1, wherein, In step (1), the Si-H bond-containing polydimethylsiloxane is selected from at least one of hydrogen-terminated polydimethylsiloxane, hydrogen-fluorinated polydimethylsiloxane, and hydrogen-phenyl polydimethylsiloxane. And / or, the hydroxyl-containing polydimethylsiloxane is selected from at least one of hydroxyl polydimethylsiloxane, monohydroxyl-terminated polydimethylsiloxane, dihydroxyl-terminated diphenyl polydimethylsiloxane, dihydroxyl-terminated diphenyl polydimethylsiloxane, dihydroxypropyl-terminated fluoropolydimethylsiloxane, silanol-hydroxyphenyl silicone oil, and hydroxyl-fluorinated polydimethylsiloxane.

4. The method according to any one of claims 1-3, wherein, In step (2), the phosphorus-containing substance is selected from at least one of ammonium polyphosphate, melamine polyphosphate, zirconium phosphate, diethyl ethylphosphonate, hexachlorocyclotriphosphononitrile, and triphenyl phosphate; And / or, the boron-containing substance is selected from at least one of zinc borate, boron nitride, phenyl borate, 2-methyl-1,3,2-benzodioxoborane and sodium perborate tetrahydrate; And / or, the nano-reinforcing filler is selected from at least two of aramid fiber, silica aerogel, alumina aerogel, silica-alumina composite aerogel, kaolin, montmorillonite, talc, sepiolite, halloysite, zirconium oxide, hollow glass microspheres and silicon carbide; And / or, the vinyl-containing polydimethylsiloxane is selected from at least one of vinyl polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, vinyl-terminated diphenyl-dimethyl copolymer siloxane, monovinyl-terminated polydimethylsiloxane, and vinyl-terminated fluoropolydimethylsiloxane.

5. The method according to any one of claims 1-3, wherein, In step (3), the catalyst is a platinum-based catalyst and / or an organotin catalyst.

6. The method according to any one of claims 1-3, wherein, The Si-H content in the polydimethylsiloxane containing Si-H bonds is 1-5 wt%; And / or, the kinematic viscosity of the hydroxyl-containing polydimethylsiloxane and the vinyl-containing polydimethylsiloxane at 25°C is independently 500-20000 cSt.

7. The composite organosilicon foam prepared by the method according to any one of claims 1-6.

8. A method for preparing an organosilicon composite fiber cloth flame-retardant material, characterized in that, The method includes: (S1) The modified composite silicone foam and the modified fiber cloth are laminated to obtain the laminated system; The modified composite organosilicon foam is obtained by modifying the composite organosilicon foam with silane coupling agent I, and the composite organosilicon foam is the composite organosilicon foam according to claim 7; The modified fiber cloth is obtained by modifying fiber cloth with silane coupling agent II. The fiber cloth is selected from at least one of inorganic fiber cloth, organic synthetic fiber cloth and natural plant fiber cloth. The silane coupling agent II may be the same as or different from the silane coupling agent I. (S2) Under a preset pressure, the composite system is cured to obtain the organosilicon composite fiber cloth flame retardant material.

9. The method according to claim 8, wherein, In step (S1), the thickness ratio of the modified composite silicone foam to the modified fiber cloth is 1:0.02-0.

08.

10. The organosilicon composite fiber cloth flame retardant material prepared by the method of claim 8 or 9.

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