Cattail wool and modification method thereof, cattail wool reinforced polyurethane foam, temperature control type cattail wool reinforced polyurethane foam and preparation method of temperature control type cattail wool reinforced polyurethane foam

Abstract

The invention discloses cattail wool, a modification method of the cattail wool, cattail wool reinforced polyurethane foam, temperature control type cattail wool reinforced polyurethane foam and a preparation method of the temperature control type cattail wool reinforced polyurethane foam. The cattail wool modification method comprises the following steps: (1.1) pretreatment of cattail wool; (1.2) preparation of a polydopamine modifier; and (1.3) modifying the typha orientalis, namely putting the pretreated typha orientalis into a polydopamine modifier, stirring, washing and drying to obtain the modified typha orientalis. According to the cattail wool modification method, reaction conditions are mild, toxic solvents are not needed, the thickness of the PDA coating can be accurately regulated and controlled through modification time, the PDA coating can improve the wettability, the thermal stability and the antibacterial performance of the fibers at the same time, PDA modification has the green process advantage and the multifunctional characteristic, and new possibility is provided for multi-functionalization of composite materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane foam, in particular to a cattail fiber and a modification method thereof, a cattail fiber reinforced polyurethane foam and a temperature control type cattail fiber reinforced polyurethane foam and a preparation method thereof. BACKGROUND

[0002] As one of the core products in the field of industrial polyurethane, polyurethane foam (PUF) plays an important role in the fields of home, building and automobile due to its unique three-dimensional open-cell structure, light texture, excellent air permeability and good mechanical properties. However, the traditional polyurethane foam has limitations in mechanical properties, durability and moisture dispersion function, which seriously restricts its application expansion in the high-end home field. In addition, with the increasing demand for sustainable materials worldwide, the application prospect of natural plant fibers in composite materials is increasingly broad. Under this background, exploring the feasibility of natural plant fiber reinforced polyurethane foam has become an important research direction to improve the comprehensive performance of materials.

[0003] Cattail fiber (CF) is a kind of natural and renewable non-wood biomass resource, which is mainly composed of cellulose, lignin and hemicellulose in chemical composition. The fiber has a tubular structure with a porous surface, and has the advantages of light weight, warmth retention and good moisture dispersion. Studies have shown that cattail fiber can improve the porosity and moisture dispersion of PUF. However, due to the coexistence of inert wax layer and polar hydroxyl group on the surface of cattail fiber, the interfacial adhesion between cattail fiber and hydrophobic polyurethane matrix is weak, which limits the improvement of mechanical properties of the composite material.

[0004] There are reports in the prior art that silane coupling agents KH550 and KH570 are used to modify cattail fiber. Although this modification method can partially improve the interfacial compatibility, it relies on toxic solvents and has a complex process, which is difficult to meet the green material preparation requirements. SUMMARY

[0005] The main purpose of the present application is to provide a green modification method of cattail fiber based on polydopamine biomimetic modification, as well as a cattail fiber reinforced polyurethane foam and a temperature control type cattail fiber reinforced polyurethane foam and a preparation method thereof.

[0006] To achieve the above purpose, the present application provides a modification method of cattail fiber, comprising the following steps:

[0007] (1.1) Pretreatment of cattail fiber

[0008] The cattail fiber is crushed and placed in an ethanol aqueous solution for ultrasonic treatment, and then dried to obtain pretreated cattail fiber;

[0009] (1.2) Preparation of polydopamine modifier

[0010] Mixing the Tris-HCl buffer solution, ethanol and dopamine hydrochloride to obtain a polydopamine modifier;

[0011] (1.3) Modification of cattail down

[0012] Placing the pretreated cattail down into the polydopamine modifier, stirring, washing and drying to obtain modified cattail down.

[0013] Further, in step (1.1), the cattail down is crushed, and then cattail down particles with a size of 60-80 mesh are screened out.

[0014] Further, in step (1.1), the concentration of the aqueous ethanol solution is 70 vol%, and the solid-liquid ratio of the crushed cattail down to the aqueous ethanol solution is 1 g:5-15 ml.

[0015] Further, in step (1.2), the concentration of the Tris-HCl buffer solution is 50 mM / L, and the pH value is 8.5.

[0016] Further, in step (1.2), the volume ratio of the Tris-HCl buffer solution to ethanol is 1:1-3, and the amount of dopamine hydrochloride added is 1-3 mg / L (i.e., 1-3 mg of dopamine hydrochloride is added to each L of the mixture of the Tris-HCl buffer solution and ethanol).

[0017] Further, in step (1.3), the solid-liquid ratio of the pretreated cattail down to the polydopamine modifier is 1 g:10 ml, and the stirring treatment time is not less than 24 h.

[0018] Further, in step (1.3), the drying treatment is performed at 101-105℃ for 24 h.

[0019] The application also provides a modified cattail down prepared by the above modification method.

[0020] The application also provides a preparation method of cattail down reinforced polyurethane foam, comprising the following steps:

[0021] (2.1) Preparation of a precursor

[0022] Mixing the modified cattail down, polyether polyol, catalyst, surfactant, foaming agent and water to obtain a precursor mixture;

[0023] (2.2) Foaming reaction

[0024] Adding isocyanate to the precursor mixture, and then performing foaming reaction to obtain cattail down reinforced polyurethane foam.

[0025] Further, in step (2.1), the polyether polyol includes 65 parts of polyether polyol 1621, 20 parts of polyether polyol 307 and 15 parts of polyether polyol 3630 by mass fraction, and the remaining raw materials are used in the following amounts: modified cattail fluff 2-8%, catalyst 1.7%, surfactant 2.5%, foaming agent 10%, and water 3%.

[0026] Further, the catalyst is composed of triethylamine, triethanolamine and bis(dimethylaminoethyl) ether in a mass ratio of 4:3:3; the surfactant is polyether polysiloxane copolymer; and the foaming agent is composed of open-cell silicone oil uniform foaming agent Si1 (BL-580) and closed-cell silicone oil Si2 (BA-7810) in a mass ratio of 1:4.

[0027] Further, in step (2.2), the amount of isocyanate added is 50% of the mass of the precursor mixture, and the specific operation mode of the foaming reaction is pouring into a mold preheated to 40°C and reacting for 10 min, then taking out and placing at room temperature for 72 h.

[0028] The application also provides a cattail fluff-reinforced polyurethane foam prepared by the above preparation method.

[0029] The application also provides a preparation method of a temperature-controlled cattail fluff-reinforced polyurethane foam, comprising the following steps:

[0030] (3.1) Preparation of phase change microcapsules

[0031] N-octadecane and isocyanate biphenyl diisocyanate are mixed to form an oil phase, and an aqueous solution of sodium lignosulfonate is used as an aqueous phase, and the oil phase and the aqueous phase are mixed and homogenized to obtain an oil-in-water emulsion;

[0032] Under stirring, an aqueous solution of ethylenediamine is added to the oil-in-water emulsion, and then emulsion reaction is carried out to obtain a phase change microcapsule emulsion;

[0033] (3.2) Phase change microcapsule coating of polyurethane foam

[0034] The above cattail fluff-reinforced polyurethane foam is immersed in the phase change microcapsule emulsion, and after impregnation treatment, it is taken out and dried to obtain the temperature-controlled cattail fluff-reinforced polyurethane foam.

[0035] Further, in step (3.1), the mass ratio of n-octadecane and isocyanate biphenyl diisocyanate is 1:1-4.

[0036] Further, in step (3.1), the concentration of the aqueous solution of sodium lignosulfonate is 0.4-1.0 wt%.

[0037] Further, in step (3.1), the mass ratio of the oil phase to the water phase is 1-4:1.

[0038] Further, in step (3.1), the concentration of the ethylenediamine aqueous solution is 2.9-6.2 wt%.

[0039] Further, in step (3.1), the mass ratio of the ethylenediamine to the isocyanate biphenyl diisocyanate is 1:3.4.

[0040] Further, in step (3.2), the immersion treatment time is 6-24 h.

[0041] Further, in step (3.2), the drying treatment condition is drying at 60℃ for 24 h.

[0042] The application also provides a temperature-controlled cattail down reinforced polyurethane foam prepared by the above preparation method.

[0043] The application has the following beneficial effects:

[0044] The application designs a green modified cattail down strategy based on polydopamine (PDA) biomimetic modification. The impurities attached to the pores and surface of the cattail down fiber are removed by ultrasonic treatment in an ethanol aqueous solution before modification. PDA can form a uniform nanoscale rough structure coating on the surface of the cattail down fiber through oxidative self-polymerization, and its active functional groups (such as hydroxyl and amino groups) can form hydrogen bonds and covalent bonds with the polyurethane matrix, thereby significantly improving the interfacial chemical bonding. In addition, PDA deposited on the surface of the cattail down fiber introduces N elements, which can enhance the chemical activity of the fiber. The use of PDA to modify the cattail down fiber significantly enhances the interfacial bonding force between the cattail down fiber and the polyurethane matrix.

[0045] The cattail down modification method of the application not only has mild reaction conditions and does not require toxic solvents, but also the thickness of the PDA coating can be accurately controlled by the modification time. The PDA coating can also improve the wettability, thermal stability and antibacterial performance of the fiber at the same time. The PDA modification has the advantages of green process and multifunctional characteristics, and provides new possibilities for the multifunctionalization of composite materials.

[0046] The PDA modified cattail down is filled into the polyurethane foam, which significantly improves the interfacial chemical bonding and optimizes the cell structure of the cattail down / polyurethane foam composite material, and the cell distribution is more uniform and regular. The tear strength, tensile strength and water absorption and moisture dispersion performance of the obtained cattail down reinforced polyurethane foam are significantly improved.

[0047] The present application further coats the surface of the cattail fiber reinforced polyurethane foam with phase change microcapsules, the phase change microcapsules are made of n-octadecane as the core material, sodium lignosulfonate as the emulsifier, and polyurea (copolymerized by isocyanate diphenyl diisocyanate and ethylenediamine) as the shell layer, and the n-octadecane phase change microcapsules are prepared by interfacial polymerization. The phase change microcapsules prepared by this method exhibit excellent temperature control and energy storage effects, and the coating of the phase change microcapsules on the surface of the polyurethane foam can make the foam have good temperature control and temperature adjustment effects.

[0048] The present application uses cattail fiber as the raw material, which is widely available and low in cost. The application potential of cattail fiber in polyurethane foam is developed, which also reduces the cost of the product and brings great economic value. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 It is a modification principle of cattail fiber of the present application, wherein (a) is a process principle of dopamine (DA) self-polymerization into polydopamine (PDA); (b) is a schematic diagram of the interaction between polydopamine (PDA) and cattail fiber (CF).

[0050] Figure 2 It is a scanning electron microscope graph of the cattail fiber reinforced polyurethane foam prepared by the present application, wherein (a) is a result electron microscope graph of the cattail fiber reinforced polyurethane foam prepared by example 1; (b) is a result electron microscope graph of the cattail fiber reinforced polyurethane foam prepared by example 2; (c) is a result electron microscope graph of the cattail fiber reinforced polyurethane foam prepared by example 3; (d) is a result electron microscope graph of the cattail fiber reinforced polyurethane foam prepared by example 4.

[0051] Figure 3 It is a scanning electron microscope graph of cattail fiber before and after modification, wherein (a), (a1) are scanning electron microscope graphs of the raw material cattail fiber before modification; (b), b1) are scanning electron microscope graphs of the modified cattail fiber prepared by example 3.

[0052] Figure 4 It is a schematic diagram of the interface interaction mechanism of the cattail fiber reinforced polyurethane foam of the present application. DETAILED DESCRIPTION

[0053] In order to make those skilled in the art more clearly understand the technical solutions described in the present application, the following examples are given for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0054] The raw materials, reagents or devices used in the following examples, if not specifically stated, can be obtained from conventional commercial channels or can be obtained by existing known methods; if not specifically stated, the methods used in the examples of the present application are methods mastered by those skilled in the art.

[0055] Polyether polysiloxane copolymer, model BD-2158, purchased from Sichuan Ruikai Bang Chemical Material Co., Ltd.; hole-silicone oil uniform bubble agent Si1 (BL-580), purchased from Nantong Bai'ang New Material Technology Co., Ltd.; closed-cell silicone oil Si2 (BA-7810), purchased from Nantong Bai'ang New Material Technology Co., Ltd.

[0056] The application provides cattail down, a modification method thereof, cattail down reinforced polyurethane foam and a preparation method thereof, and temperature-controlled cattail down reinforced polyurethane foam and a preparation method thereof.

[0057] (I) Modification of cattail down

[0058] (1.1) Pretreatment of cattail down

[0059] The cattail down is crushed, and cattail down particles with a size of 60-80 meshes are screened out by a screen, and then placed in an ethanol aqueous solution with a concentration of 70 vol% at a material-liquid ratio of 1 g: 5-15 ml for ultrasonic treatment (ultrasonic frequency 40 kHz, time 30 min), and the ultrasonic treatment is repeated three times (each time the ethanol aqueous solution needs to be replaced), and then filtered and dried at 60℃ for 24 h to obtain pretreated cattail down.

[0060] (1.2) Preparation of polydopamine modifier

[0061] Tris-HCl buffer solution (concentration 50 mM / L, pH value 8.5) and anhydrous ethanol are mixed uniformly at a volume ratio of 1:1-3, and then hydrochloric acid dopamine is added at an addition concentration of 1-3 mg / L, and stirred for 5 min to obtain a polydopamine modifier.

[0062] (1.3) Modification of cattail down

[0063] The pretreated cattail down is placed in the polydopamine modifier at a material-liquid ratio of 1 g: 10 ml, and magnetically stirred for 24 h, and then filtered, washed with distilled water until neutral, and placed in an electric heating constant temperature air drying oven for drying at 103℃ for 24 h to obtain modified cattail down.

[0064] (II) Preparation of cattail down reinforced polyurethane foam

[0065] (2.1) Preparation of precursor

[0066] The 65 parts of polyether polyol 1621, 20 parts of polyether polyol 307, 15 parts of polyether polyol 3630 were mixed uniformly, then 1.7% of catalyst (consisting of triethylamine, triethanolamine and bis(dimethylaminoethyl) ether in a mass ratio of 4:3:3), 2.5% of surfactant (polyether polysiloxane copolymer), 10% of foaming agent (consisting of open-cell silicone oil uniform foaming agent Si1 (BL-580) and closed-cell silicone oil Si2 (BA-7810) in a mass ratio of 1:4), 3% of water and 2-8% of modified cattail hair were added according to the total polyether polyol mass percentage, then stirred at a stirring speed of 3500 rpm for 20 s to obtain a precursor mixture;

[0067] (2.2) Foaming reaction

[0068] 50% of isocyanate based on the mass of the precursor mixture was added, and after stirring at a stirring speed of 3500 rpm for 7 s, it was poured into a mold (mold cavity length width height 10 cm×10 cm×20 cm) preheated to 40℃ and reacted for 10 min, then taken out and placed at room temperature for 72 h to obtain cattail hair reinforced polyurethane foam.

[0069] (Three) Preparation of temperature-controlled cattail hair reinforced polyurethane foam

[0070] (3.1) Preparation of phase change microcapsules

[0071] N-octadecane and isocyanate diphenyl diisocyanate were mixed in a mass ratio of 1:1-4 to form an oil phase, and a sodium lignosulfonate aqueous solution with a concentration of 0.4-1.0 wt% was used as the water phase. The oil phase and the water phase were mixed in a mass ratio of 1-4:1, and a homogenizing emulsifier was used to homogenize at a speed of 12000 r·min -1 for 3-5 min to obtain an oil-in-water emulsion;

[0072] The oil-in-water emulsion was transferred to a three-necked flask, and an ethylenediamine aqueous solution with a concentration of 2.9-6.2 wt% was added to the oil-in-water emulsion under the conditions of heating and stirring at 80℃ and 450 rpm. The emulsion was reacted at 80℃ for 5 h to obtain a phase change microcapsule emulsion.

[0073] The mass ratio of ethylenediamine in the ethylenediamine aqueous solution to isocyanate diphenyl diisocyanate in the oil-in-water emulsion was 1:3.4.

[0074] (3.2) Phase change microcapsule coating of polyurethane foam

[0075] The cattail hair reinforced polyurethane foam was immersed in the phase change microcapsule emulsion (the emulsion can cover the foam), and the immersion treatment was carried out for 6-24 h. After taking out, it was dried in a blast drying oven at 60℃ for 24 h to obtain a temperature-controlled cattail hair reinforced polyurethane foam.

[0076] In order to facilitate the understanding of the present application, four examples are provided below, the formulations of each example are shown in Table 1:

[0077] Table 1

[0078]

[0079] Experimental Example 1

[0080] Performance test of cattail down reinforced polyurethane foam

[0081] The performance of the cattail down reinforced polyurethane foam prepared in Examples 1-4 was tested, wherein the tensile property was determined according to standard ISO 1798-2008, the tear property was determined according to standard ISO 8067-2008, the compression deflection coefficient, hysteresis loss rate and indentation hardness were determined according to standard ISO 2439:2008(E), the water absorption and loss performance was determined according to standard ISO 22649:2016, and the mildew resistance rate was determined according to national standard GB / T18261-2013. The 72h water absorption and thickness expansion rate were determined according to national standard GB / T 1034-2008. The results are shown in Tables 2 and 3.

[0082] Table 2 Performance test results of cattail down reinforced polyurethane foam (I)

[0083] Examples Tear strength (N / cm) Tensile strength (KPa) Elongation at break (%) 1 0.67±0.02 34.65±1.14 298.08±7.77 2 0.71±0.01 36.83±0.84 294.53±6.90 3 0.75±0.02 37.31±1.83 258.01±8.45 4 0.61±0.01 35.47±1.39 228.94±5.96

[0084] Table 3 Performance test results of cattail down reinforced polyurethane foam (II)

[0085] Examples compression set coefficient (S f )]]> hysteresis loss rate (A f ) / %]]> Water absorption (%) 72 hour loss (%) 1 2.60±0.03 20.84±0.31 2423±41 53.36±0.25 2 2.66±0.02 21.11±0.12 2143±35 59.66±0.42 3 2.78±0.03 22.89±0.21 1851±52 65.55±2.11 4 2.95±0.02 23.18±0.11 1691±59 70.78±0.99

[0086] Experimental Example 2

[0087] Heat storage performance test of phase change microcapsules and temperature control performance test of temperature control type cattail down reinforced polyurethane foam

[0088] The phase change microcapsule emulsion prepared in Examples 1-4 was filtered, and then the filtered phase change microcapsules were subjected to latent heat phase change detection. The detection method was to determine the phase change performance of the phase change microcapsules by dynamic differential scanning calorimetry (DSC). A dynamic differential scanning calorimeter (DSC) was used to analyze the phase change enthalpy and phase change temperature of the phase change microcapsules during heating (cooling) under nitrogen protection. The heating (cooling) temperature range was 0-60°C, and the heating (cooling) rate was 5°C / min. The results are shown in Table 4 below.

[0089] Table 4 Heat storage performance of phase change microcapsules

[0090] Examples Peak temperature (°C) Latent heat of phase transition (J / g) 1 24.71±0.83 162.01±2.12 2 24.68±0.56 169.49±1.78 3 24.65±0.32 188.98±1.23 4 23.32±0.81 182.59±3.02

[0091] The cattail down reinforced polyurethane foams prepared in Examples 1-4 (i.e. without coating of phase change microcapsules) and the temperature-controlling cattail down reinforced polyurethane foams (i.e. coated with phase change microcapsules) were subjected to 60°C drop to room temperature time (s) test. The test method was as follows: the sample was placed in an oven at 60°C for 30 min, and then taken out and placed on a precision graphite hot plate (LCS-35plus) for temperature maintenance. The surface temperature of the layered material was tested and recorded every 3 s until it cooled to 25°C. The results are shown in Tables 5 and 6 below.

[0092] Table 5 Test results of cattail down reinforced polyurethane foams

[0093]

[0094]

[0095] Table 6 Test results of temperature-controlling cattail down reinforced polyurethane foams

[0096] Examples Time to drop from 60°C to room temperature (s) 1 563±18 2 576±13 3 585±22 4 553±17

[0097] Experimental Example 3

[0098] Effect of cattail down modification on the performance of polyurethane foams

[0099] On the basis of the examples, the modification of cattail down was omitted, and the cattail down reinforced polyurethane foams were prepared directly using the 60-80 mesh cattail down particles as raw material after crushing and screening. The performance tests were carried out in the manner of Experimental Example 1, and the results are shown in Tables 7 and 8.

[0100] Table 7 Performance test results of cattail down / polyurethane foams without PDA modification

[0101]

[0102] Table 8 Performance test results of cattail down / polyurethane foams without PDA modification

[0103]

[0104] Experimental Example 4

[0105] Characterization analysis of cattail down reinforced polyurethane foams

[0106] Figure 1Fig. (a) is a schematic diagram of the process of dopamine (DA) self-polymerization into polydopamine (PDA); Fig. (b) is a schematic diagram of the interaction between polydopamine (PDA) and cattail fiber (CF). The modification principle of the present application is that PDA modification significantly enhances the interfacial bonding force between cattail fiber and polyurethane matrix. The PDA coating forms a uniform nanoscale rough structure on the fiber surface, and its active functional groups (such as hydroxyl and amino groups) form hydrogen bonds and covalent bonds with the polyurethane matrix, significantly improving the interfacial chemical bonding. PDA is successfully deposited on the fiber surface and introduces N element, enhancing the chemical activity of the fiber. See Figure 2 and Figure 3 From the scanning electron microscope images of the cattail fiber before and after modification, it can be seen that with the increase of the addition amount of PDA modified cattail fiber, the cell diameter of the foam shows a trend of first decreasing and then increasing. At low addition amount, PDA modified fiber acts as a heterogeneous nucleation site, promoting the refinement of the cells; while at high addition amount, the physical barrier formed by the fiber agglomerates inhibits the uniform expansion of the cell wall. PDA modification may improve the compatibility of the fiber and the polyurethane matrix to some extent, and the influence on the cell growth is more moderate. The cell structure of the PDA modified PCF / PUF foam is more uniform and regular, the cell wall is relatively complete, and the number of open cells increases. This indicates that the addition of PDA modified fiber helps to optimize the microstructure of the foam, making the cell distribution more orderly, thereby improving the overall performance of the material. In addition, PDA modification improves the dispersibility of the fiber and the compatibility with the matrix, which is more conducive to the formation and expansion of the cells. In summary, PDA modification optimizes the compatibility and dispersibility of the fiber and the matrix, not only improves the uniformity and regularity of the cells, but also improves the overall porosity and apparent density of the material, providing important support for improving the comprehensive performance of the foam.

[0107] Figure 4 Fig. is a schematic diagram of the interfacial interaction mechanism of cattail fiber reinforced polyurethane foam. PDA forms an adhesive layer through self-polymerization, and its active groups (such as hydroxyl and amino groups) on the surface can form hydrogen bonds or covalent bonds with the polyurethane matrix, thereby improving the stress transfer efficiency between the fiber and the matrix.

[0108] Experimental Example 5

[0109] Effect of the ratio of crushed cattail fiber to ethanol aqueous solution on the performance of cattail fiber reinforced polyurethane foam

[0110] On the basis of Example 3, the ratio of crushed cattail fiber to ethanol aqueous solution was adjusted, and the properties of the prepared cattail fiber reinforced polyurethane foam were tested according to the method of Experimental Example 1. The results are shown in Tables 9 and 10.

[0111] Table 9

[0112]

[0113] Table 10

[0114] Experimental Example 6

[0115] Effect of volume ratio of Tris-HCl buffer solution and anhydrous ethanol on performance of cattail down reinforced polyurethane foam

[0116] On the basis of Example 3, the volume ratio of Tris-HCl buffer solution and anhydrous ethanol was adjusted, and the cattail down reinforced polyurethane foam prepared was detected for various performances in the manner of Experimental Example 1, and the results are shown in Tables 11 and 12 below.

[0117] Table 11

[0118]

[0119]

[0120] Table 12

[0121] Experimental Example 7

[0122] Effect of dopamine hydrochloride addition concentration (mg / L) on performance of cattail down reinforced polyurethane foam

[0123] On the basis of Example 3, the dopamine hydrochloride addition concentration (mg / L) was adjusted, and the cattail down reinforced polyurethane foam prepared was detected for various performances in the manner of Experimental Example 1, and the results are shown in Tables 13 and 14 below.

[0124] Table 13

[0125]

[0126] Table 14

[0127] Experimental Example 8

[0128] Effect of mass ratio of n-octadecane and isocyanate diphenyl diisocyanate on performance of temperature-controlled cattail down reinforced polyurethane foam

[0129] On the basis of Example 3, the mass ratio of n-octadecane and isocyanate diphenyl diisocyanate was adjusted, and the phase change microcapsule and the temperature-controlled cattail down reinforced polyurethane foam prepared were detected for various performances in the manner of Experimental Example 2, and the results are shown in Tables 15 and 16 below.

[0130] Table 15 Heat storage performance of phase change microcapsule

[0131]

[0132] Table 16 Test results of temperature-controllable cattail down reinforced polyurethane foam

[0133]

[0134] Experimental Example 9

[0135] Effect of mass ratio of oil phase to water phase on performance of temperature-controllable cattail down reinforced polyurethane foam

[0136] On the basis of Example 3, the mass ratio of oil phase to water phase was adjusted, and the prepared phase change microcapsules and temperature-controllable cattail down reinforced polyurethane foam were tested for various performances in the manner of Experimental Example 2, and the results are shown in Tables 17 and 18 below.

[0137] Table 17 Heat storage performance of phase change microcapsules

[0138]

[0139]

[0140] Table 18 Test results of temperature-controllable cattail down reinforced polyurethane foam

[0141]

[0142] Experimental Example 10

[0143] Effect of concentration of aqueous ethylenediamine solution on performance of temperature-controllable cattail down reinforced polyurethane foam

[0144] On the basis of Example 3, the concentration of aqueous ethylenediamine solution was adjusted, and the prepared phase change microcapsules and temperature-controllable cattail down reinforced polyurethane foam were tested for various performances in the manner of Experimental Example 2, and the results are shown in Tables 19 and 20 below.

[0145] Table 19 Heat storage performance of phase change microcapsules

[0146]

[0147] Table 20 Test results of temperature-controllable cattail down reinforced polyurethane foam

[0148]

[0149] Experimental Example 11

[0150] Effect of immersion time on performance of temperature-controllable cattail down reinforced polyurethane foam

[0151] On the basis of Example 3, the immersion time was adjusted, and the prepared temperature-controllable cattail down reinforced polyurethane foam was tested for various performances in the manner of Experimental Example 2, and the results are shown in Table 21 below.

[0152] Table 21 Test results for temperature controlled cattail down enhanced polyurethane foams

[0153] Immersion time Time to drop from 60°C to room temperature (s) 6 562±37 12 573±15 18 582±23 24 585±22

[0154] The above description is merely that of the preferred embodiments of the application and is not to be taken in a limiting sense but is made merely for the purpose of providing some preferred embodiments of the application. All modifications, equivalent replacements, improvements, and the like of any amendment within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A method for modifying cattail velvet, characterized in that: The following steps are involved: (1.1) Pretreatment of cattail fluff The cattail fluff is crushed, placed in an ethanol aqueous solution for ultrasonic treatment, and then dried to obtain pretreated cattail fluff; (1.2) Preparation of polydopamine modifier Mixing a Tris-HCl buffer solution, ethanol, and dopamine hydrochloride to obtain a polydopamine modifier; (1.3) Modification of cattail fluff The pretreated cattail fluff is placed in a polydopamine modifier, firstly stirred, then washed and dried to obtain modified cattail fluff.

2. The method for modifying cattail fluff according to claim 1, wherein: In step (1.2), the volume ratio of Tris-HCl buffer solution to ethanol is 1:1-3, and the amount of dopamine hydrochloride added is such that the concentration reaches 1-3 mg / L.

3. The method for modifying cattail fluff according to claim 1 or 2, characterized in that: In step (1.3), the material-liquid ratio of the pretreated cattail fluff and the polydopamine modifier is 1 g:10 ml, and the stirring treatment time is not less than 24 hours.

4. A modified cattail velvet, characterized in that: Prepared according to the method of claim 1, 2 or 3.

5. A method for preparing cattail velvet reinforced polyurethane foam, characterized in that: The following steps are involved: (2.1) Preparation of precursor Mixing the modified cattail fluff according to claim 4, a polyether polyol, a catalyst, a surfactant, a foaming agent and water to obtain a precursor mixture; (2.2) Foaming reaction Isocyanate is added into the precursor mixture, followed by foaming reaction to obtain cattail velvet reinforced polyurethane foam.

6. The method for preparing cattail velvet reinforced polyurethane foam according to claim 5, wherein: In step (2.1), the polyether polyol includes 65 parts of polyether polyol 1621, 20 parts of polyether polyol 307 and 15 parts of polyether polyol 3630, by mass. The amount of the remaining raw materials is 2-8% of modified cattail fluff, 1.7% of catalyst, 2.5% of surfactant, 10% of foaming agent and 3% of water, by mass percentage of the total polyether polyol.

7. The method for preparing cattail velvet reinforced polyurethane foam according to claim 5, wherein: In step (2.2), the amount of isocyanate added is 50% of the mass of the precursor mixture. The specific operation method of the foaming reaction is to pour it into a mold preheated to 40°C and react for 10 minutes, then take it out and place it at room temperature for 72 hours.

8. A cattail velvet reinforced polyurethane foam, characterized in that: Prepared according to the method of claim 5, 6 or 7.

9. A method for preparing a temperature-controlled cattail velvet reinforced polyurethane foam, characterized in that: The following steps are involved: (3.1) Preparation of phase change microcapsules n-octadecane and isocyanate diphenyl diisocyanate are mixed to form an oil phase, an aqueous solution of sodium lignin sulfonate is used as a water phase, the oil phase and the water phase are mixed, and after homogenization, an oil-in-water emulsion is obtained; Under stirring conditions, adding an ethylenediamine aqueous solution to the oil-in-water emulsion, followed by emulsification reaction, to obtain a phase-change microcapsule emulsion; (3.2) Phase change microcapsule coating of polyurethane foam The cattail velvet reinforced polyurethane foam as claimed in claim 8 is immersed in a phase change microcapsule emulsion, and after the immersion treatment, taken out and dried to obtain the temperature-controlled cattail velvet reinforced polyurethane foam.

10. A temperature-controlled cattail velvet reinforced polyurethane foam, characterized in that: Prepared according to the method as claimed in claim 9.

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