Copolymer cooling material and tobacco cooling material, and preparation methods therefor and use thereof

Abstract

The present application belongs to the technical field of the preparation of cooling materials, and particularly relates to a copolymer cooling material and a tobacco cooling material, and preparation methods therefor and the use thereof. The structure of the copolymer cooling material provided by the present application comprises a first chain segment and a second chain segment, wherein the structure of the first chain segment is as represented by formula (I), where k is selected from an integer of 20-1000; and the second chain segment is formed by bonding a repeat unit as represented by formula (A) and a repeat unit as represented by formula B, the repeat unit as represented by formula (A) and the repeat unit as represented by formula (B) being shown below, where m is selected from an integer of 1-2000, n is an integer selected from an integer of 1-2000, and * represents a binding site. The copolymer cooling material provided by the present application has a good cooling effect and high heat resistance.

Description

Copolymer cooling material, tobacco cooling material, preparation method and application thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on March 26, 2024, with application number 2024103518980 and invention name “A copolymer cooling material, tobacco cooling material, preparation method and application thereof”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application belongs to the technical field of cooling material preparation, and specifically relates to a copolymer cooling material, a tobacco cooling material, and a preparation method and application thereof. Background Art

[0004] Heat-not-burn cigarettes are one of the important categories of new tobacco products. Generally, heat-not-burn tobacco substances are heated by external heating elements. The tobacco or thin sheets are only heated but not burned. The atomizing medium in the cigarette, the flavor components in the tobacco, and the added flavoring substances are heated to produce smoke, which conveys a sense of satisfaction and part of the tobacco flavor to consumers. At the same time, the release of harmful chemical components in the smoke is significantly reduced. Its appearance and consumption method are also similar to traditional cigarettes, which to a certain extent meet the physiological and psychological needs of consumers. However, the temperature of the high-temperature atomized smoke entering the mouth through the filter segment will be higher than the combustion temperature of ordinary cigarettes, which will cause the inlet smoke to be too hot, affecting the smoking experience and smoking sensation.

[0005] Polylactic acid (PLA) is a biodegradable polyester material. Its raw material, lactic acid, comes from natural crops like corn. PLA is biodegradable and recyclable, and PLA products degrade into water and carbon dioxide in the natural environment upon disposal. Furthermore, PLA exhibits excellent mechanical properties. In the prior art, PLA is commonly used as a cooling material in cigarette filters to cool high-temperature smoke, for example, in structures such as PLA tow and PLA sheet. However, PLA has a phase transition temperature exceeding 180°C and a phase transition enthalpy of approximately 40 J / g. Even after using conventional PLA as a cooling material to treat high-temperature smoke, the smoke temperature remains elevated, making it difficult to reduce the smoke temperature below 100°C. Alternatively, the large amount used results in the cooling material occupying a significant portion of the cigarette interior. In short, PLA as a cooling material suffers from limited cooling effectiveness. Furthermore, PLA suffers from heat resistance, which limits the application and further processing of PLA ultra-thin films. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present application is to overcome the defects of the existing technology of using polylactic acid as a cooling material, which is limited in cooling and heat-resistant, thereby providing a copolymer cooling material, a tobacco cooling material, and a preparation method and application thereof.

[0007] The present application provides a copolymer cooling material, wherein the copolymer cooling material comprises a first segment and a second segment, wherein the structure of the first segment is as shown in Formula I:

[0008] wherein k is selected from an integer between 20 and 1000;

[0009] The second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B connected by a bond. The repeating unit represented by formula A and the repeating unit represented by formula B are shown as follows:

[0010] wherein m is selected from an integer of 1-2000;

[0011] n is an integer selected from 1 to 2000;

[0012] * represents the binding site.

[0013] It can be understood that in the second segment, for the repeating unit shown in formula A, its minimum repeating unit is Denoted as a, for the repeating unit shown in formula B, its minimum repeating unit is Denoted as b; the number of a in the second segment is 20-2001, the number of b in the second segment is 20-2000; the molar ratio of a to b is (1-2): (1-2).

[0014] The copolymer cooling material is a block copolymer formed by a first segment and a second segment;

[0015] Optionally, the ends of the block copolymer are capped with hydroxyl groups.

[0016] In an optional embodiment, the structure of the copolymer cooling material provided in the present application is as shown in Formula II:

[0017] wherein m' is selected from an integer of 20-2000;

[0018] n' is an integer selected from 20-2000;

[0019] k is selected from an integer of 20-1000.

[0020] The present application provides a method for preparing a copolymer cooling material, comprising the following steps:

[0021] The polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 2,4-toluene isocyanate and polyethylene glycol are dissolved in an organic reaction solvent for reaction, and an alcohol solvent is added after the reaction to precipitate a solid, thereby obtaining the copolymer cooling material.

[0022] The polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer is obtained by copolymerization of lactide and propylene carbonate (CAS: 108-32-7).

[0023] Optionally, the polylactic acid-poly(1,2-propylene carbonate) copolymer is obtained by copolymerization of lactide and propylene carbonate under catalyst conditions.

[0024] Optionally, the molar ratio of lactide to propylene carbonate is (1-2): (1-2);

[0025] The copolymerization reaction is carried out under the condition of adding a catalyst; the catalyst is selected from stannous octoate;

[0026] The mass ratio of the total mass of the lactide and the propylene carbonate to the catalyst is 1000:(1-5);

[0027] The copolymerization reaction temperature is 70-75°C, and the copolymerization reaction time is 6-12h;

[0028] After the copolymerization reaction is completed, the steps of vacuuming to remove the small molecule monomers and pelletizing the residue through a twin-screw extruder are also included.

[0029] The 2,4-toluene isocyanate and polyethylene glycol of the present application can both be obtained commercially.

[0030] Optionally, the molar ratio of the polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 2,4-toluene isocyanate and polyethylene glycol is 1:(1-2):(1-2);

[0031] The degree of polymerization of the polyethylene glycol is 20-1000;

[0032] The organic reaction solvent is selected from at least one of N,N-dimethylformamide, tetrahydrofuran, and toluene;

[0033] The volume ratio of the organic reaction solvent to the molar ratio of the polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer is (50-500):100, and the unit is mL:mmol.

[0034] Optionally, the organic reaction solvent is first subjected to a reduced pressure distillation treatment to remove water.

[0035] Optionally, the reaction temperature is 70-150° C. and the reaction time is 4-48 hours;

[0036] The alcohol solvent is selected from at least one of methanol, ethanol, propanol and butanol;

[0037] The volume ratio of the alcohol solvent to the organic reaction solvent is (1-5): (1-5);

[0038] The reaction is carried out under oxygen-free and water-free conditions;

[0039] Optionally, the reaction is carried out under N2 gas protection.

[0040] Optionally, after adding the alcohol solvent to precipitate the solid, the step of washing with alcohol and drying is further included;

[0041] Optionally, the detergent for the alcohol wash comprises methanol;

[0042] Optionally, the drying temperature is 60-80° C., and the drying environment is vacuum drying.

[0043] The present application provides an application of the above-mentioned copolymer cooling material or the copolymer cooling material prepared by the above-mentioned preparation method in tobacco cooling materials.

[0044] The present application provides a tobacco cooling material, including the copolymer cooling material described above or the copolymer cooling material prepared by the preparation method described above.

[0045] The present application also provides a method for preparing the above-mentioned tobacco cooling material, comprising the following steps:

[0046] dissolving the copolymer cooling material in an organic solvent, coating it to form a film, and drying to remove the organic solvent to obtain the tobacco cooling material;

[0047] Optionally, the mass ratio of the copolymer cooling material to dichloromethane is 1:(10-200);

[0048] Optionally, the dissolution temperature is 20-50°C;

[0049] Optionally, the organic solvent is selected from dichloromethane.

[0050] It is understood that the copolymer is completely dissolved in the organic solvent at low temperature.

[0051] The present application also provides an application of the above-mentioned tobacco cooling material or the tobacco cooling material prepared by the above-mentioned preparation method in the filter segment or cooling segment of a heat-not-burn cigarette.

[0052] The technical solution of this application has the following advantages:

[0053] 1. The copolymer cooling material provided in the present application comprises a first segment and a second segment, wherein the structure of the first segment is as shown in Formula I: wherein k is selected from an integer of 20-1000; the second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B linked together, and the repeating unit represented by formula A and the repeating unit represented by formula B are as follows: Wherein, m is selected from an integer of 1-2000; n is selected from an integer of 1-2000; and * represents a binding site. The present application provides a novel copolymer obtained by block polymerization of multiple components. This copolymer cooling material is a copolymer cooling material having specific structures of Formula I, Formula A, and Formula B. This copolymer cooling material has a high phase change enthalpy and a small contact angle, which facilitates the absorption of flue gas heat, resulting in a significant cooling effect on high-temperature flue gas. Furthermore, this copolymer cooling material has a thermal decomposition temperature exceeding 250°C and exhibits strong heat resistance. The copolymer cooling material provided in this application exhibits excellent cooling effect and strong heat resistance.

[0054] 2. The copolymer cooling material provided in this application exhibits excellent film-forming properties, mechanical properties, biodegradability, and recyclability, making it environmentally friendly. When used as a cooling material in cigarette filters, it can reduce oral discomfort caused by high-temperature tobacco smoke, achieving significant results. It overcomes the shortcomings of polylactic acid materials, such as brittleness, low impact strength, difficulty in film formation, difficulty in further processing, and high cost, making it applicable to a wider range of applications.

[0055] 3. The copolymer cooling material provided in this application is a linear thermoplastic resin that can be subsequently processed through various methods, such as blow molding, blister molding, hot pressing, and spinning, depending on the needs of the end product. The process of synthesizing the copolymer cooling material prior to molding ensures that the raw materials are free of monomers such as lactic acid, ethylene glycol, and propylene oxide, and that the molecular weight distribution is concentrated, thus ensuring a superior smoking experience and safety.

[0056] 4. This application provides a method for preparing a copolymer cooling material, comprising the steps of: dissolving a polylactic acid-polycarbonate-1,2-propylene glycol copolymer, 2,4-toluene isocyanate, and polyethylene glycol in an organic reaction solvent in the absence of oxygen and water, and reacting the mixture; after the reaction, adding an alcohol solvent to precipitate a solid, thereby obtaining the copolymer cooling material. This method is simple, and the resulting copolymer cooling material exhibits excellent cooling performance and strong heat resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0058] FIG1 is a graph showing the change in heat flow rate / weight over time of the tobacco cooling materials prepared in Examples 6-8 of the present application;

[0059] FIG2 is a thermogravimetric (TG) graph of the tobacco cooling material prepared in Examples 6-8 of the present application;

[0060] FIG3 shows the contact angle of the tobacco cooling material obtained in Example 6;

[0061] FIG4 shows the contact angle of the tobacco cooling material obtained in Example 7;

[0062] FIG5 shows the contact angle of the tobacco cooling material obtained in Example 8;

[0063] Figure 6 shows the assembly structure of the heat-not-burn cigarette cartridge and the location of the temperature measurement points;

[0064] FIG7 is an infrared spectrum of the tobacco cooling material prepared in Example 6;

[0065] FIG8 is an infrared spectrum of the tobacco cooling material prepared in Example 7;

[0066] FIG9 is an infrared spectrum of the tobacco cooling material prepared in Example 8;

[0067] FIG10 is a H-NMR spectrum of the tobacco cooling material prepared in Example 6;

[0068] FIG11 is a H-NMR spectrum of the tobacco cooling material prepared in Example 7;

[0069] FIG12 is a hydrogen nuclear magnetic spectrum of the tobacco cooling material prepared in Example 8. DETAILED DESCRIPTION

[0070] The following examples are provided for a better understanding of the present application and are not intended to limit the best implementation mode described herein. They do not limit the content and scope of protection of the present application. Any product identical or similar to the present application obtained by anyone under the inspiration of the present application or by combining the features of the present application with other prior arts shall fall within the scope of protection of the present application.

[0071] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0072] The polylactic acid-polycarbonate-1,2-propylene glycol copolymer used in the embodiments of the present application is obtained by copolymerization of lactide and propylene carbonate (CAS: 87831-99-0), specifically comprising the following steps:

[0073] 1 mol of lactide and 2 mol of propylene carbonate are mixed, and then stannous octoate is added as a catalyst (the mass ratio of the total mass of lactide and propylene carbonate to stannous octoate is 1000:1), and the mixture is heated to 70° C. for copolymerization reaction for 6 hours. After the reaction is completed, the small molecular monomers are removed by vacuum, and the residue is granulated by a twin-screw extruder to obtain the polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer.

[0074] Example 1

[0075] This embodiment provides a method for preparing a copolymer cooling material, which specifically includes the following steps:

[0076] 100 mmol of polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 100 mmol of 2,4-toluene isocyanate (TDI) and 100 mmol of polyethylene glycol (degree of polymerization of 1000) are placed under a vacuum state, the reaction system is kept anhydrous and oxygen-free, and dissolved in 200 ml of anhydrous N,N-dimethylformamide (DMF). Under the protection of N2 gas, the mixture is stirred and reacted at 100°C for 48 hours. After the reaction is completed, 200 ml of methanol solvent is added to precipitate a solid polymer. The precipitated solid polymer is fully washed with methanol to wash away unreacted compounds, and then the solid polymer is vacuum dried at 60°C to obtain the copolymer cooling material.

[0077] The copolymer cooling material prepared by the above method in this embodiment comprises a first segment and a second segment. The structure of the first segment is shown in Formula I:

[0078] Wherein, k is selected from an integer of 1000;

[0079] The second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B connected by a bond. The repeating unit represented by formula A and the repeating unit represented by formula B are shown as follows:

[0080] * represents the binding site.

[0081] The copolymer cooling material is a block copolymer formed by a first segment and a second segment;

[0082] The ends of the block copolymer are capped with hydroxyl groups.

[0083] Example 2

[0084] This embodiment provides a method for preparing a copolymer cooling material, which specifically includes the following steps:

[0085] 100 mmol of polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 100 mmol of 2,4-toluene isocyanate (TDI) and 100 mmol of polyethylene glycol (degree of polymerization of 500) are placed under a vacuum state, the reaction system is kept anhydrous and oxygen-free, and dissolved in 200 ml of anhydrous N,N-dimethylformamide (DMF). Under the protection of N2 gas, the mixture is stirred and reacted at 100°C for 48 hours. After the reaction is completed, 200 ml of methanol solvent is added to precipitate a solid polymer. The precipitated solid polymer is fully washed with methanol to wash away unreacted compounds, and then the solid polymer is vacuum dried at 60°C to obtain the copolymer cooling material.

[0086] The copolymer cooling material prepared by the above method in this embodiment comprises a first segment and a second segment. The structure of the first segment is shown in Formula I:

[0087] wherein k is selected from an integer of 500;

[0088] The second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B connected by a bond. The repeating unit represented by formula A and the repeating unit represented by formula B are shown as follows:

[0089] * represents the binding site.

[0090] The copolymer cooling material is a block copolymer formed by a first segment and a second segment;

[0091] The ends of the block copolymer are capped with hydroxyl groups.

[0092] Example 3

[0093] This embodiment provides a method for preparing a copolymer cooling material, which specifically includes the following steps:

[0094] 100 mmol of polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 100 mmol of 2,4-toluene isocyanate (TDI) and 100 mmol of polyethylene glycol (degree of polymerization of 100) are placed under a vacuum state, the reaction system is kept anhydrous and oxygen-free, and dissolved in 200 ml of anhydrous N,N-dimethylformamide (DMF). Under the protection of N2 gas, the mixture is stirred and reacted at 100°C for 48 hours. After the reaction is completed, 200 ml of methanol solvent is added to precipitate a solid polymer. The precipitated solid polymer is fully washed with methanol to wash away unreacted compounds, and then the solid polymer is vacuum dried at 60°C to obtain the copolymer cooling material.

[0095] The copolymer cooling material prepared by the above method in this embodiment comprises a first segment and a second segment. The structure of the first segment is shown in Formula I:

[0096] wherein k is an integer selected from 100;

[0097] The second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B connected by a bond. The repeating unit represented by formula A and the repeating unit represented by formula B are shown as follows:

[0098] * represents the binding site.

[0099] The copolymer cooling material is a block copolymer formed by a first segment and a second segment;

[0100] The ends of the block copolymer are capped with hydroxyl groups.

[0101] Example 4

[0102] This embodiment provides a method for preparing a copolymer cooling material, which specifically includes the following steps:

[0103] 100 mmol of polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 100 mmol of 2,4-toluene isocyanate (TDI) and 100 mmol of polyethylene glycol (degree of polymerization of 20) are placed under a vacuum state, the reaction system is kept anhydrous and oxygen-free, and dissolved in 500 ml of anhydrous N,N-dimethylformamide (DMF). Under the protection of N2 gas, the mixture is stirred and reacted at 150°C for 4 hours. After the reaction is completed, 500 ml of methanol solvent is added to precipitate a solid polymer. The precipitated solid polymer is fully washed with methanol to wash away unreacted compounds, and then the solid polymer is vacuum dried at 70°C to obtain the copolymer cooling material.

[0104] The copolymer cooling material prepared by the above method in this embodiment comprises a first segment and a second segment. The structure of the first segment is shown in Formula I:

[0105] wherein k is an integer selected from 20;

[0106] The second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B connected by a bond. The repeating unit represented by formula A and the repeating unit represented by formula B are shown as follows:

[0107] * represents the binding site.

[0108] The copolymer cooling material is a block copolymer formed by a first segment and a second segment;

[0109] The ends of the block copolymer are capped with hydroxyl groups.

[0110] Example 5

[0111] This embodiment provides a method for preparing a copolymer cooling material, which specifically includes the following steps:

[0112] 100 mmol of polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 100 mmol of 2,4-toluene isocyanate (TDI) and 100 mmol of polyethylene glycol (degree of polymerization of 800) are placed under a vacuum state, the reaction system is kept anhydrous and oxygen-free, and dissolved in 200 ml of anhydrous N,N-dimethylformamide (DMF). Under the protection of N2 gas, the mixture is stirred and reacted at 70°C for 48 hours. After the reaction is completed, 1000 ml of methanol solvent is added to precipitate a solid polymer. The precipitated solid polymer is fully washed with methanol to wash away unreacted compounds, and then the solid polymer is vacuum dried at 80°C to obtain the copolymer cooling material.

[0113] The copolymer cooling material prepared by the above method in this embodiment comprises a first segment and a second segment. The structure of the first segment is shown in Formula I:

[0114] wherein k is selected from an integer of 800;

[0115] The second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B connected by a bond. The repeating unit represented by formula A and the repeating unit represented by formula B are shown as follows:

[0116] * represents the binding site.

[0117] The copolymer cooling material is a block copolymer formed by a first segment and a second segment;

[0118] The ends of the block copolymer are capped with hydroxyl groups.

[0119] Example 6

[0120] This embodiment provides a tobacco cooling material prepared from the copolymer cooling material provided in Example 1.

[0121] The preparation method of the tobacco cooling material comprises the following steps:

[0122] The copolymer cooling material of Example 1 was placed in a flask, and dichloromethane was added. The mass ratio of the copolymer cooling material to dichloromethane was 1:20. The copolymer cooling material was completely dissolved in dichloromethane at 40° C. The dissolved solution was spin-coated into a uniform film with a thickness of 10 μm. The film was vacuum-dried and the dichloromethane solvent was removed to obtain the tobacco cooling material.

[0123] After testing, it was found that the phase change temperature range of the tobacco cooling material is 80-180°C. The phase change temperature range is based on the starting value when the tobacco cooling material begins to slowly soften, and continues until the tobacco cooling material completely softens and changes from a viscoelastic state to a flowable state. A wider phase change temperature range has a stronger ability to regulate the heat of flue gas, and can adjust higher temperature flue gas. At the same time, it also facilitates sufficient heat exchange between high-temperature flue gas and the cooling material, achieving an effective reduction in flue gas temperature. Moreover, when tobacco cooling materials with a wider phase change temperature are used in heat-not-burn tobacco, it is easier to ensure that the heat provided by the heat-not-burn tobacco in a short period of time is not enough to melt the cooling material.

[0124] Example 7

[0125] This embodiment provides a tobacco cooling material prepared from the copolymer cooling material provided in Example 2.

[0126] The preparation method of the tobacco cooling material comprises the following steps:

[0127] The copolymer cooling material of Example 2 was placed in a flask, and dichloromethane was added. The mass ratio of the copolymer cooling material to dichloromethane was 1:20. The copolymer cooling material was completely dissolved in dichloromethane at 40° C. The dissolved solution was spin-coated into a uniform film with a thickness of 10 μm. The film was vacuum-dried and the dichloromethane solvent was removed to obtain the tobacco cooling material.

[0128] Example 8

[0129] This embodiment provides a tobacco cooling material prepared from the copolymer cooling material provided in Example 3.

[0130] The preparation method of the tobacco cooling material comprises the following steps:

[0131] The copolymer cooling material of Example 3 was placed in a flask, and dichloromethane was added. The mass ratio of the copolymer cooling material to dichloromethane was 1:20. The copolymer cooling material was completely dissolved in dichloromethane at 40° C. The dissolved solution was spin-coated into a uniform film with a thickness of 10 μm. The film was vacuum-dried and the dichloromethane solvent was removed to obtain the tobacco cooling material.

[0132] Example 9

[0133] This embodiment provides a tobacco cooling material prepared from the copolymer cooling material provided in Example 4.

[0134] The preparation method of the tobacco cooling material comprises the following steps:

[0135] The copolymer cooling material of Example 4 was placed in a flask, and dichloromethane was added. The mass ratio of the copolymer cooling material to dichloromethane was 1:20. The copolymer cooling material was completely dissolved in dichloromethane at 40° C. The dissolved solution was spin-coated into a uniform thin film with a thickness of 10 μm. The film was vacuum-dried and the dichloromethane solvent was removed to obtain the tobacco cooling material.

[0136] Example 10

[0137] This embodiment provides a tobacco cooling material prepared from the copolymer cooling material provided in Example 5.

[0138] The preparation method of the tobacco cooling material comprises the following steps:

[0139] The copolymer cooling material of Example 5 was placed in a flask, and dichloromethane was added. The mass ratio of the copolymer cooling material to dichloromethane was 1:20. The copolymer cooling material was completely dissolved in dichloromethane at 40° C. The dissolved solution was spin-coated into a uniform film with a thickness of 10 μm. The film was vacuum-dried and the dichloromethane solvent was removed to obtain the tobacco cooling material.

[0140] Comparative Example 1

[0141] This comparative example provides a cooling material, which is polylactic acid (manufacturer: Anhui Fengyuan Biotechnology Co., Ltd., model: FY201, melting point 175° C., density 1.24 g / mL).

[0142] Comparative Example 2

[0143] This comparative example provides a tobacco cooling material prepared from the cooling material provided in Comparative Example 1.

[0144] The preparation method of the above-mentioned tobacco cooling material comprises the following steps:

[0145] The cooling material of Comparative Example 1 was placed in a flask, and dichloromethane was added. The mass ratio of the copolymer cooling material to dichloromethane was 1:20. The copolymer cooling material was completely dissolved in dichloromethane at 40°C. The dissolved solution was spin-coated into a uniform film with a thickness of 10 μm. The film was vacuum-dried and the dichloromethane solvent was removed to obtain a tobacco cooling material.

[0146] Test Case

[0147] The tobacco cooling materials of Examples 6-10 and the tobacco cooling material of Comparative Example 2 were tested using a differential scanning calorimeter to obtain heat flow rate-time curves of the cooling materials, and a thermogravimetric analyzer was used to obtain thermogravimetric loss curves.

[0148] The test results of Examples 6-8 are plotted with time as the horizontal axis and heat flow rate / mass as the vertical axis as shown in Figure 1; the phase change enthalpy is calculated based on the above measured data through data analysis and drawing software (origin), and the phase change enthalpy results are shown in Table 1.

[0149] It can be seen that the phase change enthalpy of the tobacco cooling material formed by the polyurethane-ethylene glycol copolymer with a polylactic acid structure in the present application is significantly increased, indicating that the tobacco cooling material provided by the present application has a large heat absorption capacity and a good cooling effect. It can effectively reduce the discomfort to the oral cavity caused by the high-temperature smoke generated by heating tobacco, and is more conducive to improving the tobacco smoking experience; the tobacco cooling material provided by the present application can achieve a significant cooling effect at a smaller dosage.

[0150] The tobacco cooling materials of Examples 6-10 and the tobacco cooling material of Comparative Example 2 were respectively tested using a thermogravimetric analyzer (TGA) to obtain the thermal decomposition temperature of the tobacco cooling materials. The test results are shown in Table 1, wherein the thermogravimetric (TG) curves of the tobacco cooling materials of Examples 6-8 are shown in Figure 2.

[0151] The thermal decomposition temperature of the tobacco cooling materials produced in this application is higher than 250°C. When tobacco is burned, the temperature of the smoke reaching the cooling area is generally below 250°C. This indicates that the cooling materials produced in this application do not decompose in high-temperature smoke, have strong heat resistance, and can be used under high-temperature conditions. The thermal decomposition temperature of Comparative Example 2 is 238°C. Although it can be used as a cooling material for novel tobacco products, its decomposition temperature is at the edge of the heating temperature of novel tobacco, which poses a risk of thermal decomposition and affecting the tobacco's taste comfort.

[0152] The contact angles of the tobacco cooling materials of Examples 6-10 and the tobacco cooling materials of Comparative Example 2 were measured by a contact angle meter, and the test results are shown in Table 1. The contact angle measurement diagrams of the tobacco cooling materials of Examples 6-8 are shown in Figures 3-5. The larger the contact angle, the lower the hydrophilicity. The lower the hydrophilicity, the worse the ability to be wetted by water and the worse the water absorption performance. The order of hydrophilicity of the tobacco cooling materials obtained in Examples 6-8 is: Example 7> Example 8> Example 6. The contact angle of the material prepared in Comparative Example 2 is 105°, which is a characteristic of a hydrophobic material. Water is the main medium for carrying heat in heated non-combustion flue gas. Increasing the hydrophilicity of the cooling material effectively increases the contact between the flue gas and the cooling material, which is of great significance to the heat transfer in the flue gas. The stronger the hydrophilicity, the more conducive it is to the transfer of heat in the flue gas and the better the cooling effect.

[0153] After the heat-not-burn cigarette is heated, the smoke temperature at the connection between the two adjacent sections is often required to be lower than a certain value, otherwise it will not only affect the user's smoking experience of the heat-not-burn cigarette. Assemble the heat-not-burn cigarette device: It consists of two parts: the heating cigarette device and the heat-not-burn cigarette cartridge, wherein the heat-not-burn cigarette cartridge is assembled by connecting the smoking section, the cooling section (the cooling section includes the tobacco cooling material of Examples 6-10 or Comparative Example 2 of the same mass) and the filter section, and 3 temperature measuring points are set, as shown in Figure 6. Heat the smoking section of the heat-not-burn cigarette to be tested to maintain stable smoke output, and perform a puff test: control the puff force to 0.5N, and puff for 3 seconds every 5 seconds so that the temperature peak reached by the tobacco remains consistent. A total of 9 puff operations are performed, and the experimental data of the first three and last three times are removed. The experimental data of the 4th, 5th and 6th puffs are counted. The temperature reduced by the cooling material = temperature measuring point 1 - temperature measuring point 2, and the smoke inlet temperature = temperature measuring point 3. The test results are shown in Table 1.

[0154] The tobacco cooling material of the present application can reduce the temperature of high-temperature smoke generated by tobacco to below 41°C (the smoke temperature of different cigarettes is stable between 30-41°C), which is significantly more effective than the same mass of polylactic acid and can effectively reduce the discomfort caused by high-temperature smoke generated by heated tobacco in the oral cavity. That is, to achieve the same cooling effect, the tobacco cooling material of the present application uses less polylactic acid than does the same amount of polylactic acid.

[0155] Table 1

[0156] Fourier transform infrared scanning tests were performed on the tobacco cooling materials of Examples 6-8, and the obtained infrared spectra are shown in Figures 7 to 9. The peak positions of the spectra in Figures 7 to 9 are basically consistent, indicating that the molecular structures of the three products are similar.

[0157] The tobacco cooling materials of Examples 6-8 were subjected to H NMR tests, and the obtained H NMR spectra are shown in Figures 10 to 12. The peak positions in the spectra in Figures 10 to 12 are basically consistent, indicating that the molecular structures of the three products are similar.

[0158] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A copolymer cooling material, characterized in that: The copolymer cooling material comprises a first segment and a second segment. The structure of the first segment is shown in Formula I: wherein k is selected from an integer between 20 and 1000; The second segment is formed by a repeating unit represented by formula A and a repeating unit represented by formula B connected by a bond. The repeating unit represented by formula A and the repeating unit represented by formula B are shown as follows: wherein m is selected from an integer of 1-2000; n is an integer selected from 1 to 2000; * represents the binding site.

2. A method for preparing a copolymer cooling material, characterized in that: The steps include: The polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 2,4-toluene isocyanate and polyethylene glycol are dissolved in an organic reaction solvent for reaction, and an alcohol solvent is added after the reaction to precipitate a solid, thereby obtaining the copolymer cooling material.

3. The method for preparing the copolymer cooling material according to claim 2, wherein: The polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer is obtained by copolymerization of lactide and propylene carbonate; Optionally, the molar ratio of lactide to propylene carbonate is (1-2): (1-2); The copolymerization reaction is carried out under the condition of adding a catalyst; the catalyst is selected from stannous octoate; The mass ratio of the total mass of the lactide and the propylene carbonate to the catalyst is 1000:(1-5); The copolymerization reaction temperature is 70-75°C, and the copolymerization reaction time is 6-12h; After the copolymerization reaction is completed, the steps of vacuuming to remove the small molecule monomers and pelletizing the residue through a twin-screw extruder are also included.

4. The method for preparing the copolymer cooling material according to claim 2 or 3, characterized in that: The molar ratio of the polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer, 2,4-toluene isocyanate and polyethylene glycol is 1:(1-2):(1-2); The degree of polymerization of the polyethylene glycol is 20-1000; The organic reaction solvent is selected from at least one of N,N-dimethylformamide, tetrahydrofuran, and toluene; The volume ratio of the organic reaction solvent to the molar ratio of the polylactic acid-polycarbonate-1,2-propylene glycol ester copolymer is (50-500):100, and the unit is mL:mmol.

5. The method for preparing the copolymer cooling material according to any one of claims 2 to 4, characterized in that: The reaction temperature is 70-150°C and the reaction time is 4-48h; The alcohol solvent is selected from at least one of methanol, ethanol, propanol and butanol; The volume ratio of the alcohol solvent to the organic reaction solvent is (1-5): (1-5); The reaction is carried out under oxygen-free and water-free conditions; Optionally, the reaction is carried out under N2 gas protection.

6. The method for preparing the copolymer cooling material according to any one of claims 2 to 5, characterized in that: After adding the alcohol solvent to precipitate the solid, the steps of washing with alcohol and drying are also included; Optionally, the detergent for the alcohol wash comprises methanol; Optionally, the drying temperature is 60-80° C., and the drying environment is vacuum drying.

7. Use of the copolymer cooling material according to claim 1 or the copolymer cooling material prepared by the preparation method according to any one of claims 2 to 6 in tobacco cooling materials.

8. A tobacco cooling material, characterized in that: The method comprises the copolymer cooling material according to claim 1 or the copolymer cooling material prepared by the preparation method according to any one of claims 2 to 6.

9. A method for preparing the tobacco cooling material according to claim 8, characterized in that: The steps include: dissolving the copolymer cooling material in an organic solvent, coating it to form a film, and drying to remove the organic solvent to obtain the tobacco cooling material; Optionally, the mass ratio of the copolymer cooling material to dichloromethane is 1:(10-200); Optionally, the dissolution temperature is 20-50°C; Optionally, the organic solvent is selected from dichloromethane.

10. Use of the tobacco cooling material according to claim 8 or the tobacco cooling material prepared by the preparation method according to claim 9 in the filter segment or cooling segment of a heat-not-burn cigarette.

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