Light, thin, warm-keeping and temperature-adjusting modified polymer aerogel composite material and preparation method thereof

Abstract

A lightweight, thermal insulation and temperature-adjusting modified polymer aerogel composite material and a preparation method thereof are provided. The composite material includes a heat insulation matrix with a topological and closed-cell foaming structure; And an enhanced thermal insulation low thermal conductivity element embedded in the bubble wall of the thermal insulation matrix, i.e. the non-porous part. Due to the special foaming process, the aerogel phase change thermal insulation composite material has a tiny closed-cell structure similar to that of aerogel materials, and aerogel particles and phase change microcapsules are added, so that the internal cell structure and porosity are further improved, and the aerogel phase change thermal insulation composite material has a certain phase change temperature regulation function and excellent thermal insulation performance.

Claims

1. A polyamide/NBR blended elastomer microcellular foaming material, comprising the following components in parts by mass: 40-80 parts of NBR, 20-60 parts of polyamide, 0-100 parts of a filler, 0-50 parts of a plasticizer, 0.5-4 parts of a vulcanizing agent, 0-5 parts of a vulcanization accelerator, 1-3 parts of an antioxidant, 2-10 parts of a foaming agent, 0.5-4 parts of an active agent, and 1-4 parts of an anti-scorching agent; wherein the polyamide/NBR blended elastomer microcellular foaming material has a bimodal cell size distribution; the polyamide/NBR blended elastomer microcellular foaming material is prepared by the following method: 1) mixing processing: setting a temperature of an internal mixer above 60? C., firstly adding polyamide, adding NBR into the internal mixer after the polyamide is melted, then optionally adding a filler, optionally adding a plasticizer, and adding an antioxidant in turn; mixing for a first time, then setting a temperature of an open mill below 60? C., adding a vulcanizing agent, optionally adding a vulcanizing accelerator, optionally adding a foaming agent, optionally adding an active agent; mixing for a second time, discharging to obtain a rubber compound; 2) obtaining the polyamide/NBR blended elastomer microcellular foaming material with the bimodal cell size distribution and a topological and closed-cell foaming structure by a two-stage curing method: putting the rubber compound into an extruder, and extruding a required shape to obtain a molded rubber compound; putting the molded rubber compound into a molding machine at a temperature above 120? C. for a first curing; then raising the temperature to above 150? C. for a second curing, and then preparing the polyamide/NBR blended elastomer microcellular foaming material with the bimodal cell size distribution and the topological and closed-cell foaming structure by a rapid cooling method.

2. The polyamide/NBR blended elastomer microcellular foaming material according to claim 1, wherein a cell size of the bimodal cell size distribution is in a range of 2 ?m to 50 ?m and 50 ?m to 250 ?m, respectively.

3. A modified polymer aerogel composite material, comprising: a heat insulation matrix having a topological and closed-cell foaming structure; and an element with enhanced thermal insulation and low thermal conductivity embedded in a bubble wall of the thermal insulation matrix; wherein a material of the heat insulation matrix is the polyamide/NBR blended elastomer microcellular foaming material according to claim 1.

4. The modified polymer aerogel composite material according to claim 3, wherein the element with enhanced thermal insulation and low thermal conductivity is selected from aerogel; in the modified polymer aerogel composite material, a mass percentage content of the element with enhanced thermal insulation and low thermal conductivity is 2 wt %-15 wt %.

5. The modified polymer aerogel composite material according to claim 3, wherein the modified polymer aerogel composite material further comprises phase change microcapsules, wherein the phase change microcapsules are located in closed cells of the heat insulation matrix; in the modified polymer aerogel composite material, a mass percentage content of the phase change microcapsules is 5-25 wt %.

6. A method of using the modified polymer aerogel composite material according to claim 3 in the fields of clothing, shoes and hats, cold chain packaging, architecture and aerospace.

7. The method of using according to claim 6, wherein the element with enhanced thermal insulation and low thermal conductivity is selected from aerogel; in the modified polymer aerogel composite material, a mass percentage content of the element with enhanced thermal insulation and low thermal conductivity is 2 wt %-15 wt %.

8. The method of using according to claim 6, wherein the modified polymer aerogel composite material further comprises phase change microcapsules, wherein the phase change microcapsules are located in closed cells of the heat insulation matrix; in the modified polymer aerogel composite material, a mass percentage content of the phase change microcapsules is 5-25 wt %.

9. A modified polymer aerogel composite material, comprising: a heat insulation matrix having a topological and closed-cell foaming structure; and an element with enhanced thermal insulation and low thermal conductivity embedded in a bubble wall of the thermal insulation matrix; wherein the modified polymer aerogel composite material further comprises phase change microcapsules, wherein the phase change microcapsules are located in closed cells of the heat insulation matrix; in the modified polymer aerogel composite material, a mass percentage content of the phase change microcapsules is 5-25 wt % and wherein a material of the heat insulation matrix is a polyamide/NBR blended elastomer microcellular foaming material comprising the following components in parts by mass: 40-80 parts of NBR, 20-60 parts of polyamide, 0-100 parts of a filler, 0-50 parts of a plasticizer, 0.5-4 parts of a vulcanizing agent, 0-5 parts of a vulcanization accelerator, 1-3 parts of an antioxidant, 2-10 parts of a foaming agent, 0.5-4 parts of an active agent, and 1-4 parts of an anti-scorching agent; wherein the polyamide/NBR blended elastomer microcellular foaming material has a bimodal cell size distribution; the polyamide/NBR blended elastomer microcellular foaming material is prepared by the following method: 1) mixing processing: setting a temperature of an internal mixer above 60? C., firstly adding polyamide, adding NBR into the internal mixer after the polyamide is melted, then optionally adding a filler, optionally adding a plasticizer, and adding an antioxidant in turn; mixing for a first time, then setting a temperature of an open mill below 60? C., adding a vulcanizing agent, optionally adding a vulcanizing accelerator, optionally adding a foaming agent, optionally adding an active agent; mixing for a second time, discharging to obtain a rubber compound; 2) obtaining the polyamide/NBR blended elastomer microcellular foaming material with the bimodal cell size distribution and a topological and closed-cell foaming structure by a two-stage curing method: putting the rubber compound into an extruder, and extruding a required shape to obtain a molded rubber compound; putting the molded rubber compound into a molding machine at a temperature above 120? C. for a first curing; then raising the temperature to above 150? C. for a second curing, and then preparing the polyamide/NBR blended elastomer microcellular foaming material with the bimodal cell size distribution and the topological and closed-cell foaming structure by a rapid cooling method.

10. A preparation method of the polyamide/NBR blended elastomer microcellular foaming material according to claim 1, comprising the following steps: 1) mixing processing: setting the temperature of the internal mixer above 60? C., firstly adding polyamide, adding NBR into the internal mixer after the polyamide is melted, then optionally adding the filler, optionally adding the plasticizer and adding the antioxidant in turn; mixing for the first time, then setting the temperature of the open mill below 60? C., adding the vulcanizing agent, optionally adding the vulcanizing accelerator, optionally adding the foaming agent, optionally adding the active agent; mixing for the second time, discharging to obtain the rubber compound; 2) obtaining the polyamide/NBR blended elastomer microcellular foaming material with the bimodal cell size distribution and the topological and closed-cell foaming structure by the two-stage curing method: putting the rubber compound into the extruder, and extruding the required shape to obtain the molded rubber compound; putting the molded rubber compound into the molding machine at the temperature above 120? C. for the first curing; then raising the temperature to above 150? C. for the second curing, and then preparing the polyamide/NBR blended elastomer microcellular foaming material with the bimodal cell size distribution and the topological and closed-cell foaming structure by the rapid cooling method.

11. The preparation method according to claim 10, wherein in step 1), a first mixing time is 5 min to 7 min; a second mixing time is 3 min-5 min; a first mixing temperature is 60? C.-90? C.; a second mixing temperature is 40? C.-50? C.; and/or, in step 2), a first curing pressure is 7 MPa to 20 MPa, a first curing temperature is 120? C. to 180? C., and a first curing time is 5 min to 30 min; a second curing pressure is 8 MPa-25 MPa, a second curing temperature is 150? C.-190? C., and a second curing time is 5 min-30 min; and/or, in step 2), a cooling rate of rapid cooling is greater than 4? C./s.

12. The preparation method according to claim 10, wherein a cell size of the bimodal cell size distribution is in a range of 2 ?m to 50 ?m and 50 ?m to 250 ?m, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of the cross-sectional structure of the modified polymer aerogel composite material of the present invention, wherein, 1 is a closed cell, 2 is a matrix, 3 is an element with enhanced thermal insulation and low thermal conductivity, and 4 is a phase change microcapsule.

(2) FIG. 2 is a schematic diagram of the topological structure of the modified polymer aerogel composite material of the present invention.

(3) FIG. 3 is a comparison of thermal conductivity between the modified polymer aerogel composite prepared by the present invention and other typical thermal insulation materials for textile and garment.

(4) FIG. 4 is a graph showing the relationship between the mass ratio of aerogel in the modified polymer aerogel composite and the thermal conductivity of the modified polymer aerogel composite.

(5) FIG. 5 is a DTA analysis diagram of the equivalent heat storage effect of the modified polymer aerogel composite material containing phase change microcapsules prepared by the present invention (heating endothermic cooling and cooling and exothermic heating).

DETAILED DESCRIPTION OF THE EMBODIMENTS

(6) [Polyamide/NBR Blended Elastomer Microcellular Foaming Material]

(7) As mentioned above, the present invention provides a polyamide/NBR blended elastomer microporous foaming material, which can be used for the elastic matrix of the composite material, and the formula (parts by mass) of the foaming material is as follows: 40-80 parts of NBR, 20-60 parts of polyamide, 0-100 parts of a filler, 0-50 parts of a plasticizer, 0.5-4 parts of a vulcanizing agent, 0-5 parts of a vulcanizing accelerator, 1-3 parts of an antioxidant and 1-4 parts of a scorching inhibitor;

(8) The foaming material has a bimodal cell size distribution.

(9) According to one embodiment of the present invention, the foaming material is a three-dimensional porous foaming material with a topological closed-cell foamed structure.

(10) According to one embodiment of the present invention, the cell diameters of the bimodal cell size distribution are in the range of 2 ?m to 50 ?m and 50 ?m to 250 ?m, respectively.

(11) According to one embodiment of the present invention, the number of cells in the range of 2 ?m to 50 ?m accounts for more than 50%, and the number of cells in the range of 50 ?m to 250 ?m accounts for less than 50%.

(12) Nitrile butadiene rubber (NBR) is made from butadiene and acrylonitrile by emulsion polymerization. It has the characteristics of excellent oil resistance, high wear resistance, good heat resistance and strong adhesion. NBR is mainly used to make oil-resistant rubber products, which can be used in air at 120? C. or oil at 150? C. for a long time. In addition, it also has good water resistance, air tightness and excellent bonding performance. It is widely used to prepare various oil-resistant rubber products, various oil-resistant gaskets, gaskets, sleeves, flexible packaging, soft hoses, printing and dyeing cots, cable rubber materials, etc., and has become an essential elastic material in the industries of automobiles, aviation, petroleum, and copying.

(13) Polyamide (PA), commonly known as nylon, is a general term for polymers containing amide groups in the repeating units of the main chain of macromolecules. Polyamide can be prepared by ring-opening polymerization of internal acid amine, or by polycondensation of diamine and diacid. Polyamide has good comprehensive properties, including mechanical properties, heat resistance, wear resistance, chemical resistance and self-lubrication, and has low friction coefficient, certain flame retardancy and easy processing. It is suitable for being filled and modified with glass fiber and other fillers, which can improve performance and expand application scope.

(14) According to the present invention, NBR and polyamide are compounded, and a polyamide/NBR blended elastomer microcellular foaming material with special bimodal cell size distribution is prepared, which has the characteristics of self-reinforcement, good aging resistance and flame retardancy, good toughness, tear strength and buffering performance, and has many advantages of light weight, insulation, weather resistance, flame retardancy, low water absorption, high and low temperature resistance, non-toxicity, environmental protection and the like.

(15) According to one embodiment of the present invention, the NBR is selected from but not limited to one or more of ordinary NBR, hydrogenated NBR, carboxyl NBR and the like.

(16) According to one embodiment of the present invention, the polyamide is selected from but not limited to one or more of terpolymer nylon, long carbon chain nylon and the like.

(17) According to one embodiment of the present invention, the filler is selected from but not limited to one or more of carbon black, white carbon black, calcium carbonate, short fiber and the like.

(18) According to one embodiment of the present invention, the plasticizer is selected from but not limited to one or more of paraffin oil, naphthenic oil, dioctyl phthalate and the like.

(19) According to one embodiment of the present invention, the vulcanizing agent is selected from but not limited to one or more of sulfur, DCP and the like.

(20) According to one embodiment of the present invention, the vulcanization accelerator is selected from but not limited to one or more of D, DM, TMTD, TAIC, CBS and the like.

(21) According to one embodiment of the present invention, the antioxidant is selected from but not limited to one or more of TK100, N-phenyl-N-cyclohexyl p-phenylenediamine (4010), 4020 and the like.

(22) According to one embodiment of the present invention, the anti-scorching agent is selected from but not limited to N-cyclohexyl thiotitanate imide (CTP).

(23) According to one embodiment of the present invention, the formula further comprises a foaming agent and an active agent, wherein the foaming agent is 2-10 parts by mass and the active agent is 0.5-4 parts by mass.

(24) According to one embodiment of the present invention, the foaming agent is selected from but not limited to one or more of azodicarbonamide (AC), 4,4-oxydibenzenesulfonyl hydrazide (OBSH) and the like.

(25) According to one embodiment of the present invention, the active agent is selected from, but not limited to, zinc oxide.

(26) [Preparation of Polyamide/NBR Blended Elastomer Microcellular Foaming Material]

(27) As mentioned above, the present invention further provides a preparation method of the polyamide/NBR blended elastomer microcellular foaming material, which comprises the following steps: 1) mixing processing: setting the temperature of the internal mixer above 60? C., firstly adding polyamide, adding NBR into the internal mixer after the polyamide is melted, then adding or not adding a filler, adding or not adding a plasticizer and adding an antioxidant in turn; mixing for the first time, then setting the temperature of an open mill below 60? C., adding a vulcanizing agent, adding or not adding a vulcanizing accelerator, adding or not adding a foaming agent, adding or not adding an active agent; mixing for the second time, discharging to obtain a rubber compound; 2) obtaining a microcellular foaming material with a bimodal cell size distribution and a topological and closed-cell foaming structure by a two-stage curing method: putting the rubber compound into an extruder, and extruding the required shape; putting the molded rubber compound into a molding machine at a temperature above 120? C. for primary curing; then raising the temperature to above 150? C. for secondary curing, and then preparing the microcellular foaming material with a bimodal cell size distribution and a topological and closed-cell foaming structure by a rapid cooling method.

(28) According to one embodiment of the present invention, the preparation method further comprises the following steps: 3) shaping, deodorizing and softening: shaping, deodorizing and softening the microporous foaming material obtained in step 2).

(29) According to one embodiment of the present invention, in step 1), the first mixing time is 4 min-7 min; the second mixing time is 3 min-5 min.

(30) According to one embodiment of the present invention, in step 1), the first mixing temperature is 60-90? C.; the second mixing temperature is 40? C.-50? C.

(31) According to one embodiment of the present invention, in step 2), a plate, a tube or other desired shape is extruded.

(32) According to one embodiment of the present invention, in step 2), the first curing pressure is 7 MPa to 20 MPa, the first curing temperature is 120? C. to 180? C., and the first curing time is 5 min to 30 min.

(33) According to one embodiment of the present invention, the material cured for the first time is initially foamed, and it needs to be continuously treated under the conditions of elevated temperature and pressure so that the phase change microcapsules are precipitated and attached to the inner wall of the closed cells of the thermal insulation matrix, so as to maintain the integrity of the closed cells of the thermal insulation matrix, and the pre-solidified sample is cured for the second time; When the foaming process reaches equilibrium, the mold is opened after rapid cooling (the cooling rate is better than 4? C./s), and the sample is taken out to obtain the microporous composite with a bimodal cell size distribution.

(34) According to one embodiment of the present invention, in step 2), the pressure for the second curing is 8 MPa to 25 MPa, the temperature for the second curing is 150? C. to 190? C., and the time for the second curing is 5 min to 30 min.

(35) According to an embodiment of the present invention, in step 2), the cooling rate of rapid cooling is greater than 4C/s.

(36) According to one embodiment of the present invention, in step 3), the shaping, deodorizing and softening is vulcanization at 140-180? C. for 10-60 min, and the vulcanization mode is hot air vulcanization, microwave radiation crosslinking or infrared radiation crosslinking.

(37) [Use of Polyamide/NBR Blended Elastomer Microcellular Foaming Material]

(38) As mentioned above, the present invention further provides use of the polyamide/NBR blended elastomer microcellular foaming material in preparation of a thermal insulation material.

(39) [Modified Polymer Aerogel Composites]

(40) As mentioned above, the present invention provides a modified polymer aerogel composite material, which includes: a heat insulation matrix having a topological, closed-cell foaming structure; and an element with enhanced thermal insulation and low thermal conductivity, which is embedded in the bubble wall of the thermal insulation matrix.

(41) According to one embodiment of the present invention, the bubble wall of the thermal insulation matrix refers to the part of the thermal insulation matrix that forms the topological closed-cell foaming structure, and in essence, the bubble wall of the thermal insulation matrix is the non-porous part of the thermal insulation matrix.

(42) According to an embodiment of the present invention, the element with enhanced thermal insulation and low thermal conductivity can be selected from aerogels, such as inorganic aerogel nanoparticles or organic aerogels.

(43) Specifically, the inorganic aerogel nanoparticles can be selected from one or more of alumina nanoparticles, zirconia nanoparticles, silica nanoparticles, magnesium fluoride nanoparticles, calcium fluoride nanoparticles, silicon carbide nanoparticles, boron carbide nanoparticles, boron nitride nanoparticles, titanium nitride nanoparticles, titanium dioxide-silica nanoparticles, vanadium oxide-titanium dioxide nanoparticles and titanium oxide nanoparticles.

(44) Specifically, the organic aerogels can be selected from one or more of resorcinol-formaldehyde aerogels, melamine-formaldehyde aerogels, urethane aerogels, polyimide aerogels, polymethylmethacrylate aerogels, polystyrene aerogels, polydicyclopentadiene aerogels, carbon nanotubes and the like.

(45) According to an embodiment of the present invention, the aerogel can be a solid powder with a three-dimensional network microstructure with at least one dimension (preferably at least two or three dimensions) between 5 nm-100 nm.

(46) According to one embodiment of the present invention, the aerogel can be in the form of particles or short fibers.

(47) In the present invention, the thermal conductivity of the solid (such as the thermal insulation matrix) is further reduced and the heat conduction path is reduced by the element with enhanced thermal insulation and low thermal conductivity (such as aerogel, specifically inorganic aerogel nanoparticles or organic aerogel) embedded in the bubble wall of the thermal insulation matrix, and the modified polymer aerogel composite material with thermal insulation is obtained.

(48) According to one embodiment of the present invention, in the composite material, the mass percentage content of the thermal insulation-strengthening low thermal conductivity element is 2%-15 wt %, such as 2%, 3 wt %, 4 wt %, 5%, 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt % or 15 wt %.

(49) According to an embodiment of the present invention, the composite material further includes phase change microcapsules, and the phase change microcapsules are located in closed cells of the heat insulation matrix.

(50) According to one embodiment of the present invention, the phase change microcapsules are located on the inner wall of the closed cell of the heat insulation matrix.

(51) In the present invention, the phase change microcapsules are further synthesized into the closed cells of the heat insulation matrix (specifically located on the inner wall of the closed cells of the heat insulation matrix), so as to store energy, absorb and release heat, generate temperature regulation, and form a micro air conditioning environment.

(52) According to one embodiment of the present invention, the phase change microcapsule is a solid-liquid phase change microcapsule which changes phase at 15-35 C, and can be adjusted according to design requirements. Illustratively, paraffin can be included in the phase change microcapsule, and further exemplarily, the phase change microcapsule is selected from urea-formaldehyde resin-paraffin phase change microcapsule and the like.

(53) According to one embodiment of the present invention, the mass percentage content of phase change microcapsules in the composite material is 5%-25 wt %, such as 5%, 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt %, 15 wt %, 16 wt %, 17 wt %, 18 wt %, 19 wt %, 20 wt %, 21 wt %, 22 wt %, 23 wt %, 24 wt % or 25 wt %.

(54) According to one embodiment of the present invention, the material of the heat insulation matrix is an elastic polymer foaming porous material.

(55) According to one embodiment of the present invention, the material of the heat insulation matrix is the polyamide/NBR blended elastomer microcellular foaming material.

(56) For three-dimensional porous foaming materials, the thermal conductivity is mainly determined by the thermal conductivity of the gas in the closed cell (Knudsen effect) and the thermal conductivity of the solid in the bubble wall, while radiation and convection are basically ignored. According to the present invention, the solid thermal conductivity in the bubble wall is reduced by embedding elements with enhanced thermal insulation and low thermal conductivity; in addition, the heat storage effect of phase change microcapsules is utilized to adjust the local temperature microcirculation; and then, the nucleation and growth of microbubbles are controlled to obtain a heat insulation matrix with bimodal cell size distribution, thereby further reducing the gas thermal conductivity.

(57) According to the present invention, the phase change microcapsules and the enhanced thermal insulation and low thermal conductivity elements (such as aerogels) are integrated in a polymer skeleton matrix (i.e., the thermal insulation matrix) to form a complete micro-nano nanocomposite material, thus effectively avoiding the defect that the phase change microcapsules and the element with enhanced thermal insulation and low thermal conductivity (such as aerogels) fall off during use.

(58) According to an embodiment of the present invention, the composite material further includes a moisture permeable microstructure. In the present invention, the moisture permeable microstructure is obtained through a certain mechanical micromachining and punching treatment, so that the function of exhausting moisture is achieved.

(59) The composite material of the present invention (also called Topological Flex gel) is a modified polymer aerogel composite prepared by using proprietary technology and an exclusive special process. The composite material has a 3D multi-level complex structure. As shown in FIG. 1, its three-dimensional porous topological network skeleton (as shown in FIG. 2) has a thin-walled structure, which effectively reduces the solid-state heat conduction, while the gas-condensed structure greatly limits the gas heat conduction and heat convection. At the same time, the material has shading effect, which greatly reduces the radiation heat transfer at room temperature. With this structure, the composite material has extremely low thermal conductivity, and with its excellent super-flexibility, light drape and excellent windproof and warmth retention, it will become a brand-new subversive scientific and technological material for winter warmth retention in the future textile field.

(60) [Preparation Method of Modified Polymer Aerogel Composite Material]

(61) As mentioned above, the present invention further provides a preparation method of the modified polymer aerogel composite material, which includes the following steps: mixing a material forming a heat insulation matrix with an element with enhanced thermal insulation and low thermal conductivity, adding or not adding phase change microcapsules, adding or not adding other additives, foaming, and cooling to obtain the modified polymer aerogel composite material.

(62) According to one embodiment of the present invention, secondary foaming is required in the method, so that the element with enhanced thermal insulation low thermal conductivity and the phase change microcapsule form the required structure.

(63) Specifically, in the mixing processing step of the preparation method of the polyamide/NBR blended elastomer microcellular foaming material, an element with enhanced thermal insulation and low thermal conductivity is added, and phase change microcapsules are added or not, and then the modified polymer aerogel composite material of the present invention is obtained in a two-stage curing method. More specifically, during the second mixing of the mixing process, an element with enhanced thermal insulation and low thermal conductivity is added, and phase change microcapsules are added or not.

(64) [Use of Modified Polymer Aerogel Composite Material]

(65) As mentioned above, the present invention further provides use of the modified polymer aerogel composite material in various fields such as clothing, shoes and hats, cold chain packaging, architecture, aerospace and the like. Specifically, it can be used for: thermal insulation clothing, bedding, shoes, hats, gloves, multifunctional single-soldier sleeping bags, tents, cold chain packaging, building insulation (interior decoration), automobile insulation, new energy battery insulation devices, etc.

(66) According to one embodiment of the present invention, the material is used for shoe materials, in particular for the thermal insulation layer of shoe materials. It can be compounded with other materials of shoes by hot melting or chemical fusion.

(67) According to one embodiment of the present invention, the composite material can be compounded with various knitted and woven fabrics by a conventional hot melt lamination compounding method.

(68) [Various Specific Uses of Modified Polymer Aerogel Composite Materials]

(69) As mentioned above, the present invention provides a composite phase change thermal insulation material, which includes the modified polymer aerogel composite material.

(70) According to one embodiment of the present invention, the composite phase change thermal insulation material is a composite phase change thermal insulation film material or a composite phase change thermal insulation body material.

(71) According to one embodiment of the present invention, the area density of the composite phase change thermal insulation film is 30-100 g/m.sup.2. the present invention further provides a phase change thermal-insulation batting capsule, which comprises the modified polymer aerogel composite material. Specifically, it can also be wherein the phase change microcapsules are solid-liquid phase change microcapsules which undergo phase change at 15-35? C., the average particle size of the solid-liquid phase change microcapsules is 1-3 microns, the enthalpy retention rate is 20-99%, and the mass percentage content of the phase change microcapsules in the composite material is 10-15%. the present invention further provides a temperature-adjusting phase-change thermal insulation membrane, which includes the modified polymer aerogel composite material. Specifically, it can also be wherein the mass percentage content of aerogel in the composite material is 5-15%. More specifically, the area density of the diaphragm is 30-100 g/m.sup.2. More specifically, the thickness of the temperature-adjusting phase-change thermal insulation membrane is 0.3 mm-8 mm to 8 mm, and the pinhole density is 1 to 30 cells/cm.sup.2, or it may not be perforated. the present invention further provides a thermal diaphragm, which comprises the modified polymer aerogel composite material. The purpose is to provide a unique method to replace the current thermal insulation flocs and improve the micro-nano composite phase change and aerogel fusion.

(72) In the following, the technical solution of the present invention will be further described in detail with specific examples. It should be understood that the following examples only illustrate and explain the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies realized based on the above contents of the present invention are covered in the scope that the present invention aims to protect.

(73) Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available or can be prepared by known methods.

Example 1

(74) The formula of the modified polymer aerogel composite material in the embodiment of the present invention is as follows: 100 parts by mass of polyamide/NBR blended elastomer microporous foaming material. 4 parts by mass of aerogel (polyimide aerogel) 10 parts by mass of phase change microcapsule (urea-formaldehyde resin-paraffin phase change microcapsule) 4 parts by mass of a foaming agent (AC).

(75) The formula (parts by mass) of the polyamide/NBR blended elastomer microcellular foaming material is as follows: 70 parts of NBR (NBR); 60 parts of polyamide (PA); 10 parts of a foaming agent (AC); 2 parts of an active agent (zinc oxide); 20 parts of a filler (white carbon black); 10 parts of a plasticizer (paraffin oil); 3 portions of a vulcanizing agent (sulfur); 1 part of a vulcanization accelerator (TMTD); 2 parts of an antioxidant (N-phenyl-N-cyclohexyl p-phenylenediamine); 1 part of an anti-scorching agent (N-(Cyclohexylthio)phtalimide (CTP)).

(76) The preparation method of the composite material in this embodiment includes the following steps:

(77) 1) Preparation of a Rubber Compound (1) the temperature of the internal mixer was set at 80? C. and the rotating speed at 60 rpm; firstly PA was fed, then NBR was fed into the internal mixer after the PA was melted; plastination was carried out for 60 s, the ram was lifted, and an antioxidant was added and mixed for 90 s; the ram was lifted, a filler and a plasticizer were added and continuously mixed for 90 s; then the rubber was discharged to obtain the master rubber; (2) the temperature of the mill roller was raised to 50? C., and the master rubber was into the open mill to be kneaded for 3-4 min; then a vulcanizing agent, a vulcanization accelerator, a foaming agent, an active agent, aerogel and phase change microcapsules were added, mixed, cooled to room temperature to stand for 24 hours.

(78) 2) First Curing

(79) Molding pre-sulfurization: the rubber mixture was put into the mold, the hot press pressure was 9 MPa, the temperature was 140? C., and the pre-sulfurization time was 10 min; then the rubber compound was left in the mold to wait for the second curing.

(80) 3) Secondary Curing

(81) The material cured for the first time was foamed initially, and it needed to be treated continuously under the conditions of elevated temperature and pressure so that the phase change microcapsules were precipitated and attached to the surface of the closed cells of the thermal insulation matrix, so as to maintain the integrity of the closed cells of the thermal insulation matrix. The temperature range of the pre-solidified sample for the second curing was 160? C. and the pressure was 15 MPa. When the foaming process reached equilibrium, the mold was quickly cooled (the cooling rate was preferably greater than 4? C./s), and the sample was taken out to obtain the bimodal cell size distribution.

(82) The present invention adopts a unique two-step foaming process. The primary foaming (primary curing) affects the distribution of closed cells, foam walls and element with enhanced thermal insulation and low thermal conductivity, and the secondary foaming (secondary curing) controls the precipitation distribution of phase change microcapsules.

(83) According to the phase change thermal insulation composite material and the preparation method thereof, the composite material prepared in this embodiment not only has the characteristics of excellent thermal insulation, overall lightness, softness, moisture conduction and quick drying, but also avoids the problem that the phase change microcapsules in the existing thermal insulation flocs are easy to fall off, thus effectively ensuring the intelligent temperature adjustment function of the phase change thermal insulation composite material.

(84) The composite material prepared in this example not only has high thermal insulation, but also maintains excellent flexibility (see Table 1 and Table 2).

(85) Table 1 Properties of Phase Change Thermal Insulation Composites

(86) TABLE-US-00001 Sample 1 Density (g/cm.sup.3) 0.056 Thermal conductivity 0.016 (W/mK) Hardness (Shore C) 4 Rebounding 32%

(87) Table 2 Performance Comparison Between the Phase Change Thermal Insulation Composite of the Present Invention and the Existing Thermal Insulation Materials

(88) TABLE-US-00002 CLO Equivalent Thick- value thermal ness CLO per unit conductivity Sample (mm) value thickness coefficient Polyimide needle-punched floc 13 2.32 0.18 36.14 Ultrafine hollow polyester flocs 25 3.74 0.15 43 Thermal storage floc (hollow 15 2.13 0.14 45.45 mixed far infrared fiber) Example 1 1.50 3.81 2.54 2.535

(89) Exemplary embodiments of the present invention have been described above. However, the protection scope of this application is not limited to the above-mentioned embodiments. Any modification, equivalent substitution, improvement, etc. made by a person skilled in the art within the spirit and principle of the present invention should be included in the protection scope of the present invention.