Cellulose composite material, its preparation method and application

Abstract

The present invention relates to the field of temperature-reducing materials for heat-not-burn cigarettes, and discloses a cellulose composite material, a preparation method thereof and an application thereof. The material is composed of cellulose, a biomass phase-change material and silica aerogel, and the weight ratio of the cellulose, the biomass material to the silica aerogel is 1:0.1-2.0:0.1-0.3. The cellulose composite material provided by the present invention has a uniform porous network structure at the micron scale, and the porosity is 96-98%, which can provide rich channels for hot flue gas, so that it can fully contact with the temperature-reducing materials in the material to achieve the purpose of sufficient temperature reduction; at the same time, it can adsorb and filter harmful substances in large particles in the flue gas, and provide pure, healthier and appropriately temperatured flue gas to smokers.

Description

Technical Field

[0001] The present invention relates to the field of temperature-reducing materials for heat-not-burn cigarettes, and specifically, to cellulose composite materials, their preparation methods, and applications. Background Art

[0002] Most traditional cigarettes obtain nicotine by directly burning the cigarettes. However, due to the existence of combustion reactions in this traditional method, some harmful substances are inevitably produced.

[0003] In recent years, in order to reduce non-essential harmful substances in cigarettes, researchers have obtained nicotine through a new approach, namely, heating the tobacco without burning it. In this method, special tobacco is heated, but the tobacco can only be heated and not burned. The gas volatilizes at a specific temperature to produce smoke.

[0004] However, the aforementioned specific temperature is usually relatively high. The prior art mainly uses phase change temperature-reducing materials to cool the longitudinally flowing high-temperature smoke. Due to the limitations of the filter rod length and the phase change temperature-reducing materials, and the relatively fast smoke flow rate, it is difficult to cool the materials. The transverse heat transfer of the overheated smoke through the filter rod makes consumers feel their lips being burned when sucking, affecting the consumer experience and even posing a risk of burns.

[0005] "Preparation and Properties of Eicosane / Cellulose Acetate Phase Change Filter Materials" published by Guo Xinyue et al. uses cellulose diacetate as the carrier matrix and eicosane as the phase change material, and prepares eicosane / cellulose acetate composite phase change filter materials by electrospinning technology, and further accelerates its endothermic cooling rate by doping single-walled carbon nanotubes.

[0006] In addition, some researchers have set up a reflux section in the gap between the tobacco section and the filter section to reduce the temperature of the smoke; some researchers have added cooling elements at the filter tip to reduce the temperature of the smoke.

[0007] However, these prior arts all have the drawbacks of unsatisfactory cooling effects and high costs.

[0008] Therefore, there is an urgent need for a new material that can effectively reduce the temperature of the smoke of heat-not-burn cigarettes. Summary of the Invention

[0009] The purpose of the present invention is to overcome the aforementioned problems existing in the prior art, and provide a new material for reducing the temperature of the smoke of heat-not-burn cigarettes.

[0010] To achieve the above object, a first aspect of the present invention provides a cellulose composite material, which is composed of cellulose, a biomass phase change material and silica aerogel, and the biomass phase change material is selected from at least one of konjac glucomannan, pectin, gelatin and carrageenan; the weight ratio of the amounts of the cellulose, the biomass phase change material and the silica aerogel powder is 1: 0.1-2.0: 0.1-0.3, and the average pore size of the cellulose composite material is 50-250 μm, and the porosity is 96-98%.

[0011] A second aspect of the present invention provides a method for preparing the cellulose composite material described in the first aspect above, and the method includes:

[0012] (1) In the presence of water, sodium hydroxide and urea are subjected to a first reaction to obtain a mixture I;

[0013] (2) The mixture I and cellulose are subjected to a second reaction to obtain a mixture II;

[0014] (3) The mixture II and the biomass phase change material and the silica aerogel powder are subjected to a third reaction to obtain a mixture III;

[0015] (4) The mixture III is subjected to aging regeneration, freeze molding, solvent replacement and drying in sequence to obtain the cellulose composite material;

[0016] wherein, the weight ratio of the amounts of the cellulose, the biomass phase change material and the silica aerogel powder is 1: 0.1-2.0: 0.1-0.3, and the control conditions are such that the average pore size of the obtained cellulose composite material is 50-250 μm, and the porosity is 96-98%.

[0017] A third aspect of the present invention provides an application of the cellulose composite material described in the first aspect above in a heat-not-burn electronic cigarette.

[0018] The cellulose composite material provided by the present invention has a uniform micron-level porous network structure, and the porosity is 96-98%. It can provide rich channels for the hot smoke, so that it can fully contact with the temperature-reducing material in the material to achieve the purpose of fully reducing the temperature; at the same time, it can adsorb and filter large-particle harmful substances in the smoke, and provide pure, healthier and appropriately temperatureed smoke to smokers.

[0019] The preparation raw materials of the cellulose composite material provided by the present invention have the advantages of environmental protection, wide sources and low prices. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the temperature measurement positions for measuring the temperature reduction effect of the preferred cellulose composite material of the present invention. Detailed implementation mode

[0021] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the values between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as having specific advantages herein.

[0022] As described above, the first aspect of the present invention provides a cellulose composite material, which is composed of cellulose, a biomass phase change material and silica aerogel. The biomass phase change material is selected from at least one of konjac glucomannan, pectin, gelatin, and carrageenan; the weight ratio of the cellulose, the biomass phase change material to the silica aerogel powder is 1:0.1 - 2.0:0.1 - 0.3, the average pore size of the cellulose composite material is 50 - 250 μm, and the porosity is 96 - 98%.

[0023] Preferably, the cellulose is selected from at least one of pulp cellulose, cotton linter cellulose, and microcrystalline cellulose.

[0024] Preferably, the average particle size of the silica aerogel powder is 15 - 25 μm, and the porosity is 95 - 98%.

[0025] The present invention has no particular limitation on the method for preparing the aforementioned cellulose composite material, and those skilled in the art can select according to the known technical means in the art. However, in order to obtain a cellulose composite material with better cooling effect, the present invention provides a preferred specific implementation mode. As described above, the second aspect of the present invention provides a method for preparing the cellulose composite material described in the first aspect, and the method includes:

[0026] (1) In the presence of water, sodium hydroxide and urea are subjected to a first reaction to obtain mixture I;

[0027] (2) The mixture I and cellulose are subjected to a second reaction to obtain mixture II;

[0028] (3) The mixture II and the biomass phase change material, silica aerogel powder are subjected to a third reaction to obtain mixture III;

[0029] (4) The mixture III is subjected to aging regeneration, freeze molding, solvent replacement and drying in sequence to obtain the cellulose composite material;

[0030] Among them, the weight ratio of the cellulose, the biomass phase change material and the silica aerogel powder is 1: 0.1-2.0: 0.1-0.3, and the control conditions are such that the average pore diameter of the obtained cellulose composite material is 50-250 μm, and the porosity is 96-98%.

[0031] Preferably, the weight ratio of the water, the sodium hydroxide and the urea is 100: 8-15: 10-15.

[0032] Preferably, the weight ratio of the water to the cellulose is 100: 1-10. More preferably, the weight ratio of the water to the cellulose is 100: 1-3.

[0033] Preferably, the average particle size of the silica aerogel powder is 15-25 μm, and the porosity is 95-98%. The inventors of the present invention have found that in this preferred case, the obtained cellulose composite material has a better cooling effect and purer flue gas.

[0034] According to a preferred embodiment, in step (1), the conditions of the first reaction at least satisfy: carried out under stirring, and the stirring speed is 300-1000 rpm, the temperature is 25-30 °C, and the time is 0.1-0.3 h.

[0035] According to another preferred embodiment, in step (2), the conditions of the second reaction at least satisfy: carried out under stirring, and the stirring speed is 300-600 rpm, the temperature is -15 °C to -25 °C, and the time is 0.5-1 h.

[0036] Preferably, in step (3), the conditions of the third reaction at least satisfy: carried out under stirring, and the stirring speed is 500-1500 rpm, the temperature is 60-90 °C, and the time is 0.5-2 h. The inventors of the present invention have found that in this preferred case, the obtained cellulose composite material has a more uniform porous network structure, making the cooling effect of the material more significant.

[0037] Preferably, in step (4), the conditions of the aging and regeneration at least satisfy: the temperature is 20-30 °C, and the time is 0.5-2 h.

[0038] Preferably, the conditions of the freeze molding at least satisfy: the temperature is -25 °C to -35 °C, and the time is 4-12 h.

[0039] Preferably, the conditions of the drying at least satisfy: the pressure is 1-5 Pa, the temperature is -70 °C to -80 °C, and the time is 12-36 h.

[0040] According to a particularly preferred embodiment, before the drying, the material after freeze forming is successively subjected to solvent replacement with alcohol and water I. The temperature of the solvent replacement is 20 - 30 °C, and the time is 2 - 6 h. Exemplarily, the alcohol can be ethanol.

[0041] It should be noted that the present invention has no particular limitation on the dosages of ethanol and water I in the solvent replacement, as long as the material after freeze forming can be completely immersed in ethanol and water I.

[0042] As described above, the third aspect of the present invention provides an application of the regenerated cellulose composite material described in the first aspect in a heat - non - combustible electronic cigarette.

[0043] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, all raw materials used are commercially available products.

[0044] It should be noted that the room temperature in the present invention is 25 ± 2 °C.

[0045] Sodium hydroxide: Purchased from Shanghai Hushi Chemical Industry Co., Ltd.

[0046] Urea: Purchased from Tianjin Zhiyuan Chemical Reagent Co., Ltd.

[0047] Pulped cellulose: Purchased from Cangzhou Bobin Thermal Insulation Materials Co., Ltd.

[0048] Microcrystalline cellulose: Purchased from Sinopharm Chemical Reagent Co., Ltd.

[0049] Konjac glucomannan: Purchased from Hubei Qiangsen Konjac Technology Co., Ltd.

[0050] Gelatin: Analytical pure, purchased from Tianjin Kemiou Chemical Reagent Co., Ltd.

[0051] Xanthan gum: Purchased from Huaju Biotechnology Co., Ltd.

[0052] Silica aerogel powder (hereinafter referred to as aerogel powder):

[0053] Aerogel powder I: The porosity is 95%, and the average particle size is 20 μm, purchased from Apiaihe New Materials Co., Ltd.

[0054] Aerogel powder II: The porosity is 95%, and the average particle size is 120 μm, purchased from Apiaihe New Materials Co., Ltd.

[0055] Aerogel powder III: The porosity is 90%, and the average particle size is 20 μm, purchased from Apiaihe New Materials Co., Ltd.

[0056] Example 1

[0057] This example is used to illustrate the cellulose composite material of the present invention according to the formulation and process parameters in Table 1, and the cellulose composite material is prepared by the method described as follows.

[0058] The preparation method of the cellulose composite material includes the following steps:

[0059] (1) At room temperature, in 100 g of water, 8.64 g of sodium hydroxide and 14.81 g of urea are subjected to a first reaction to obtain mixture I;

[0060] The conditions of the first reaction are: stirring at a speed of 350 rpm for 0.2 h;

[0061] (2) 3 g of cellulose is subjected to a second reaction with the mixture I to obtain mixture II;

[0062] The conditions of the second reaction are: the temperature is -17 °C, and stirring is carried out at a speed of 500 rpm for 0.5 h;

[0063] (3) The mixture II is subjected to a third reaction with the biomass phase change material and silica aerogel powder to obtain mixture III;

[0064] The conditions of the third reaction are: the temperature is 80 °C, and stirring is carried out at a speed of 1000 rpm for 1 h;

[0065] (4) The mixture III is subjected to aging regeneration, freeze molding, solvent replacement and drying in sequence to obtain the cellulose composite material C1;

[0066] The conditions of the aging are: aging at room temperature for 1 h;

[0067] The conditions of the freeze molding are: freezing at -30 °C for 8 h;

[0068] The conditions of the solvent replacement are: at room temperature, the freeze-molded material is soaked in ethanol and water I for 1 h and 0.5 h respectively, and repeated 3 times;

[0069] The conditions of the drying are: vacuum freeze-drying at a pressure of 1 Pa and a temperature of -80 °C for 24 h.

[0070] Example 2

[0071] Example 2 is carried out using the same process as Example 1. The difference is that in this example:

[0072] The raw materials and process parameters used for preparing the cellulose composite material are different. For details, see Table 1.

[0073] The cellulose composite material C2 is prepared.

[0074] Example 3

[0075] In this embodiment, a cellulose composite material is prepared using similar raw materials and methods as in Embodiment 1, except that: the silica aerogel powder I is replaced with an equal weight of silica aerogel powder II, and the remaining conditions are the same as those in Embodiment 1, resulting in the preparation of cellulose composite material C3.

[0076] Embodiment 4

[0077] In this embodiment, a cellulose composite material is prepared using similar raw materials and methods as in Embodiment 1, except that: the temperature in the third reaction is 40 °C, and the remaining conditions are the same as those in Embodiment 1, resulting in the preparation of cellulose composite material C4.

[0078] Embodiment 5

[0079] In this embodiment, a cellulose composite material is prepared using similar raw materials and methods as in Embodiment 1, except that: the temperature in the third reaction is 110 °C, and the remaining conditions are the same as those in Embodiment 1, resulting in the preparation of cellulose composite material C5.

[0080] Embodiment 6

[0081] In this embodiment, a cellulose composite material is prepared using similar raw materials and methods as in Embodiment 1, except that: the silica aerogel powder I is replaced with an equal weight of silica aerogel powder III, and the remaining conditions are the same as those in Embodiment 1, resulting in the preparation of cellulose composite material C6.

[0082] Comparative Example 1

[0083] In this comparative example, a cellulose composite material is prepared using similar raw materials and methods as in Embodiment 1, except that: the amount of cellulose used is 7 g, and the remaining conditions are the same as those in Embodiment 1, resulting in the preparation of cellulose composite material DC1.

[0084] Comparative Example 2

[0085] In this comparative example, a cellulose composite material is prepared using similar raw materials and methods as in Embodiment 1, except that: no silica aerogel powder is used, the dosage ratio of cellulose to the biomass phase change material is the same as that in Embodiment 1, and the sum of the dosages of the two is the same as the sum of the dosages of the three in Embodiment 1, and the remaining conditions are the same as those in Embodiment 1, resulting in the preparation of cellulose composite material DC2.

[0086] Comparative Example 3

[0087] In this comparative example, a cellulose composite material is prepared using similar raw materials and methods as in Embodiment 1, except that: the amount of silica aerogel powder I used is 1 g, and the remaining conditions are the same as those in Embodiment 1, resulting in the preparation of cellulose composite material DC3.

[0088] Comparative Example 4

[0089] This comparative example uses raw materials and methods similar to those of Example 1 to prepare a cellulose composite material. The difference is that the biomass phase change material is xanthan gum, and the other conditions are the same as those of Example 1, and the cellulose composite material DC4 is prepared.

[0090] Comparative Example 5

[0091] This comparative example uses raw materials and methods similar to those of Example 1 to prepare a cellulose composite material. The difference is that the biomass phase change material is replaced with cellulose in equal weight, and the other conditions are the same as those of Example 1, and the cellulose composite material DC5 is prepared.

[0092] Test Example 1

[0093] The cellulose composite materials (hereinafter referred to as samples) prepared in the examples and comparative examples were measured for pore size and porosity, and were applied to the cooling section of a heat-not-burn electronic cigarette to determine the cooling effect.

[0094] 1. Method for measuring pore size: Cut the sample into small pieces of 5mm×5mm×1mm, and fix it on an aluminum alloy sample stage with conductive adhesive. Use a particle sputtering instrument (JFC1600, JEOL Ltd., Japan) to sputter gold particles onto the material for 80 s to make it conductive. Then observe the network structure of the sample through a scanning electron microscope (SEM) at magnifications of ×50, ×100, ×500, ×850, and ×1000.

[0095] Select 6 representative SEM images of the sample, and use ImageProPlus6.0 software to perform pore size distribution statistics.

[0096] 2. Method for measuring porosity: The drainage method is adopted. First, weigh the mass (m0) of the sample to be measured with an analytical balance, and immerse the sample in pure ethanol for 5 min. Weigh the total mass m1 of the beaker containing ethanol and the sample. Then put the beaker containing the sample into a vacuum dryer and evacuate it until there are no bubbles overflowing in the beaker. Finally, take out the sample and weigh the mass m2 of the beaker containing the remaining ethanol. The porosity (ε) is calculated by the following formula:

[0097]

[0098] 3. Method for measuring the cooling effect: Insert the thermocouple wire of the thermocouple into different positions of the self-made cigarette for real-time temperature measurement. The specific temperature measurement positions are as Figure 1 shown.

[0099] Specifically, the sample was cut into a rectangle with a length of 8 mm and a width of 120 mm, and then folded into a cylinder cooling section with a diameter of 7 mm and a length of 8 mm. The prepared cooling section was encapsulated in a self-made "mini-cigarette" (with a total length of 45 mm and a cavity length of 20 mm). During the test, the tobacco was lit with a lighter. After the smoke became stable and lasted for 10 s, the thermocouple wires were used to measure the temperature of Figure 1 the temperature measurement points 1, 2 and

[0100] 4. Test method for tar content: Refer to the method of GB / T 19609-2004 Determination of total particulate matter and tar in cigarettes by conventional analytical smoking machines for cigarettes to test the tar content of cigarettes.

[0101] Table 1

[0102]

[0103]

[0104] Note: In the solvent replacement, "1 + 0.5, 3" means soaking in ethanol for 1 h first and then in water for 0.5 h, repeating 3 times.

[0105] Continued Table 1

[0106]

[0107]

[0108] Note: In the solvent replacement, "1 + 0.5, 3" means soaking in ethanol for 1 h first and then in water for 0.5 h, repeating 3 times.

[0109] Table 2

[0110] Average pore size (μm) Porosity (%) Temperature drop (°C) Reduction rate of tar content (%) Example 1 153 97 20 14.17 Example 2 180 98 19 13.50 Example 3 124 98 22 13.02 Example 4 157 96 18 12.48 Example 5 138 97 16 11.79 Example 6 141 96 17 11.24 Comparative Example 1 224 96 15 10.67 Comparative Example 2 166 97 16 11.93 Comparative Example 3 175 93 13 10.85 Comparative Example 4 184 91 10 9.66 Comparative Example 5 191 95 12 10.34

[0111] From the results in Table 2, it can be seen that the cellulose composite material provided by the present invention has a uniform micron-level porous network structure, with a porosity of 96 - 98% or more, and has a significant cooling effect. At the same time, the content of harmful substances in the smoke is also relatively reduced.

[0112] 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 technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A cellulose composite material, characterized in that, This material is composed of cellulose, biomass phase change material and silica aerogel composite, and the biomass phase change material is selected from konjac glucomannan and / or gelatin; the weight ratio of the cellulose, the biomass phase change material and the silica aerogel powder is 1: 0.1 - 2.0: 0.1 - 0.3, the average pore size of the cellulose composite material is 50 - 250μm, and the porosity is 96 - 98%; The average particle size of the silica aerogel powder is 15 - 25µm, and the porosity is 95 - 98%.

2. The composite material according to claim 1, wherein The cellulose is selected from at least one of pulp cellulose, cotton linter cellulose and microcrystalline cellulose.

3. A method for preparing the cellulose composite material according to claim 1 or 2, characterized in that, This method includes: (1) In the presence of water, sodium hydroxide and urea are subjected to a first reaction to obtain mixture I; (2) The mixture I and cellulose are subjected to a second reaction to obtain mixture II; (3) The mixture II, biomass phase change material and silica aerogel powder are subjected to a third reaction to obtain mixture III; (4) The mixture III is subjected to aging regeneration, freeze molding, solvent replacement and drying in sequence to obtain the cellulose composite material; Among them, the weight ratio of the cellulose, the biomass phase change material and the silica aerogel powder is 1: 0.1 - 2.0: 0.1 - 0.3, and the control conditions are such that the average pore size of the obtained cellulose composite material is 50 - 250μm and the porosity is 96 - 98%; the average particle size of the silica aerogel powder is 15 - 25µm and the porosity is 95 - 98%.

4. The method according to claim 3, wherein, The weight ratio of the water, the sodium hydroxide and the urea is 100: 8 - 15: 10 - 15.

5. The method according to claim 3 or 4, wherein, The weight ratio of the water and the cellulose is 100: 1 - 10.

6. The method according to claim 3 or 4, wherein The conditions of the first reaction at least satisfy: carried out under stirring, and the stirring speed is 300 - 1000 rpm, the temperature is 25 - 30°C, and the time is 0.1 - 0.3 h.

7. The method according to claim 3 or 4, wherein In step (2), the conditions of the second reaction at least satisfy: carried out under stirring, and the stirring speed is 300 - 600 rpm, the temperature is -15°C to -25°C, and the time is 0.5 - 1 h.

8. The method according to claim 3 or 4, wherein, In step (3), the conditions of the third reaction at least satisfy: carried out under stirring, and the stirring speed is 500 - 1500 rpm, the temperature is 60 - 90°C, and the time is 0.5 - 2 h.

9. The method according to claim 3 or 4, wherein In step (4), the conditions of the aging regeneration at least satisfy: the temperature is 25 - 30°C, and the time is 0.5 - 2 h.

10. The method according to claim 3 or 4, wherein The conditions of the freeze molding at least satisfy: the temperature is -25°C to -35°C, and the time is 4 - 12 h.

11. The method according to claim 3 or 4, wherein The conditions of the drying at least satisfy: the pressure is 1 - 5 Pa, the temperature is -70°C to -80°C, and the time is 12 - 36 h.

12. Application of the cellulose composite material according to claim 1 or 2 in a heat - non - combustible electronic cigarette.

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