Foaming material, preparation method and application thereof, and refrigeration equipment liner

Abstract

The invention relates to the field of high polymer materials, in particular to a foaming material, a preparation method and application thereof and an inner container of refrigeration equipment. The foaming material comprises the following raw material components: a POE (Polyolefin Elastomer) base material, high impact polystyrene, a modified foaming agent and a compatilizer, wherein the compatilizer is selected from at least one of SEBS (Styrene-Ethylene-Butylene-Styrene) grafted maleic anhydride, PP (Polypropylene) grafted maleic anhydride and POE grafted maleic anhydride; the mass ratio of the POE base material to the compatilizer to the modified foaming agent to the high impact polystyrene is 100: (1-5): (80-100): (800-1000). According to the foaming material, the toughness can be improved, the heat conductivity coefficient is reduced, meanwhile, the mechanical performance and the processing performance of the foaming material cannot be affected, and the problem of cracking is not prone to occurring in the processing process.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, specifically to a foaming material, its preparation method and application, and the inner liner of a refrigeration device. Background Technology

[0002] In the fields of polymer material preparation technology, foam material preparation technology, and polymer material processing technology, plastic products are widely used in various fields due to their advantages such as being lightweight, easy to process, and low in cost. Among them, high-impact polystyrene (HIPS) is widely used in the manufacture of refrigerator liners and outer shells due to its excellent mechanical properties and good processing performance. However, traditional HIPS materials have some problems, such as a high thermal conductivity, which can easily lead to uneven temperature inside the refrigerator and affect the cooling effect; and insufficient toughness, which can easily cause cracking during processing.

[0003] Existing solutions primarily involve modifying the formulation of HIPS materials by adding modifiers such as toughening agents and antioxidants to improve their toughness and reduce their thermal conductivity. For example, some studies have added polyolefin elastomers (POE) as toughening agents to HIPS materials to enhance their toughness; others have attempted to add materials with low thermal conductivity, such as nanomaterials and ceramic materials, to HIPS materials to reduce their thermal conductivity.

[0004] Although existing solutions can improve the performance of HIPS materials to some extent—for example, existing toughening agents such as POE can improve the toughness of HIPS materials—excessive addition can affect the mechanical and processing properties of HIPS materials and cannot solve the problem of cracking during processing.

[0005] Therefore, how to reduce the thermal conductivity of HIPS materials and solve the cracking problem without affecting their mechanical and processing properties is the main challenge currently facing the technology. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of decreased mechanical and processing performance and easy cracking during processing caused by improving the toughness and reducing the thermal conductivity of HIPS materials in the prior art. This invention provides a foamed material, its preparation method and application, and a refrigeration equipment liner. This foamed material can improve the toughness and reduce the thermal conductivity without affecting the mechanical and processing performance of the foamed material, and it is not easy to crack during processing.

[0007] To achieve the above objectives, the first aspect of the present invention provides a foaming material, wherein the raw material components of the foaming material include POE substrate, high-impact polystyrene, modified foaming agent, and compatibilizer, wherein the compatibilizer is selected from at least one of SEBS grafted maleic anhydride, PP grafted maleic anhydride, and POE grafted maleic anhydride; the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent, and the high-impact polystyrene is 100:1-5:80-100:800-1000.

[0008] Preferably, the mass ratio of the POE substrate, SEBS-g-MAH, modified foaming agent and the high-impact polystyrene is 100:3-5:90-100:900-1000.

[0009] Preferably, the compatibilizer is SEBS grafted maleic anhydride.

[0010] Preferably, the preparation process of the modified foaming agent includes mixing bicarbonate, epoxy resin, pentaerythritol tetramercaptoester, dichloromethane, triethylamine and petroleum ether.

[0011] Preferably, the bicarbonate is sodium bicarbonate and / or potassium bicarbonate.

[0012] Preferably, the mass ratio of the epoxy resin, the bicarbonate, and the pentaerythritol tetramercaptoester is 1:8-12:0.5-0.8.

[0013] Preferably, the POE substrate is a polyethylene octene coelastomer and / or a polyethylene butene coelastomer.

[0014] Preferably, the high-impact polystyrene has a melt index of 0.5-0.6 g / min at a temperature of 200°C and a load of 5 kg.

[0015] Preferably, the raw material components of the foaming material further include antioxidants.

[0016] Preferably, the mass ratio of the antioxidant to the POE substrate is 0.5-0.8:100.

[0017] Preferably, the thermal conductivity of the foamed material is 0.12-0.21 W / (m·K), and the notched impact strength is 18-24 MPa.

[0018] A second aspect of the present invention provides a method for preparing a foamed material, the method comprising the following steps: (1) Mix POE substrate, antioxidant, compatibilizer, high-impact polystyrene and modified foaming agent to obtain mixture A; (2) Extruding the mixture A; The compatibilizer is selected from at least one of SEBS grafted maleic anhydride, PP grafted maleic anhydride, and POE grafted maleic anhydride; the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent, and the high-impact polystyrene is 100:1-5:80-100:800-1000.

[0019] Preferably, the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent, and the high-impact polystyrene is 100:3-5:90-100:900-1000.

[0020] Preferably, the compatibilizer is SEBS grafted maleic anhydride.

[0021] Preferably, the preparation process of the modified foaming agent includes mixing bicarbonate, epoxy resin, pentaerythritol tetramercaptoester, dichloromethane, triethylamine and petroleum ether.

[0022] Preferably, the bicarbonate is sodium bicarbonate and / or potassium bicarbonate.

[0023] Preferably, the mass ratio of the epoxy resin, the bicarbonate, and the pentaerythritol tetramercaptoester is 1:8-12:0.5-0.8.

[0024] Preferably, the POE substrate is a polyethylene octene coelastomer and / or a polyethylene butene coelastomer.

[0025] Preferably, the high-impact polystyrene has a melt index of 0.5-0.6 g / min at a temperature of 200°C and a load of 5 kg.

[0026] Preferably, in step (1), the conditions for mixing I include at least: a rotation speed of 500-1000 rpm and a time of 2-10 min.

[0027] Preferably, the conditions for extrusion I include at least: a temperature of 180-220°C and a pressure of 2-5 MPa; Preferably, step (1) further includes adding an antioxidant during the mixing process.

[0028] Preferably, the mass ratio of the antioxidant to the POE substrate is 0.5-0.8:100.

[0029] A third aspect of the present invention provides the application of the foamed material described in the first aspect and / or the foamed material obtained by the preparation method described in the second aspect in plastic products and automotive products.

[0030] A fourth aspect of the present invention provides a refrigeration liner, wherein the refrigeration liner is prepared using the foaming material described in the first aspect and / or the foaming material obtained by the preparation method described in the second aspect.

[0031] The beneficial effects of the present invention through the above technical solution are as follows: The foamed material provided by this invention, through the synergistic effect of a specific ratio of POE substrate, high-impact polystyrene, modified foaming agent, and compatibilizer, can effectively improve the toughness of the foamed material and reduce its thermal conductivity without affecting its mechanical and processing properties. It is less prone to cracking during processing. Moreover, the foamed material does not contain a large amount of fillers or additives. While achieving low thermal conductivity and high toughness, it avoids the problems of decreased mechanical strength and deteriorated processing performance caused by excessive additives (such as the traditional large addition of POE), thus achieving a balance of comprehensive performance and significant economic benefits.

[0032] The foaming material provided by this invention, by adding a specific compatibilizer, can significantly improve the compatibility and phase structure of POE substrate and high-impact polystyrene, forming a more stable and uniform microstructure, preventing performance defects caused by phase separation; moreover, it can fully exert the toughening effect of POE, while the uniformly distributed micropores can effectively terminate crack propagation, significantly improving the toughness of the material and enhancing its impact resistance, solving the stress cracking problem that easily occurs in HIPS during processing (such as injection molding), and greatly improving the yield and durability of the products; in addition, the addition of the compatibilizer improves the strength and ductility of the melt, improves the rheological properties of the blend system, making the material easier to plasticize, flow and mold during processing, reducing processing defects, and improving production efficiency and product quality stability.

[0033] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0034] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0035] In a first aspect, the present invention provides a foaming material, wherein the raw material components of the foaming material include a POE substrate, high-impact polystyrene (HIPS), a modified foaming agent, and a compatibilizer, wherein the compatibilizer is selected from at least one of SEBS grafted maleic anhydride, PP grafted maleic anhydride, and POE grafted maleic anhydride; the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent, and the high-impact polystyrene is 100:1-5:80-100:800-1000.

[0036] During their research, the inventors unexpectedly discovered that the synergistic effect of a specific ratio of POE substrate, high-impact polystyrene, modified foaming agent, and compatibilizer can effectively improve the toughness of the foamed material and reduce its thermal conductivity without affecting its mechanical and processing properties. This also prevents cracking during processing. Furthermore, the foamed material does not contain a large amount of filler or additives. While achieving low thermal conductivity and high toughness, it avoids the problems of decreased mechanical strength and deteriorated processing performance caused by excessive additives (such as the traditional method of adding large amounts of POE), thus achieving a balance of comprehensive performance and significant economic benefits.

[0037] According to the present invention, the compatibilizer is selected from at least one of SEBS grafted maleic anhydride (SEBS-g-MAH), PP grafted maleic anhydride (PP-g-MAH), and POE grafted maleic anhydride (POE-g-MAH). POE-g-MAH is a polymeric compatibilizer prepared by grafting maleic anhydride (MAH) onto polyolefin elastomer (POE) as the matrix resin; PP-g-MAH refers to a polymeric compatibilizer prepared by introducing maleic anhydride (MAH) onto the PP molecular chain through a grafting reaction using polypropylene (PP) as the matrix. SEBS-g-MAH is prepared by grafting modification using styrene-ethylene-butene-styrene block copolymer (SEBS) as the matrix.

[0038] According to the present invention, in order to further improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material, preferably, the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent and the high-impact polystyrene is 100:3-5:90-100:900-1000.

[0039] According to the present invention, in order to further improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material, preferably, the compatibilizer is SEBS grafted maleic anhydride.

[0040] According to the present invention, preferably, the preparation process of the modified foaming agent includes: mixing bicarbonate, epoxy resin, pentaerythritol tetramercaptoester, dichloromethane, triethylamine, and petroleum ether. The inventors have discovered that, in this preferred embodiment, by modifying the traditional bicarbonate foaming agent, encapsulating the bicarbonate foaming agent with epoxy resin, and using a compatibilizer to improve the interface, the foaming agent is successfully made to preferentially exist at the interface between the POE and HIPS phases. This interface region naturally becomes an ideal nucleation point upon heating, eliminating the need for additional nucleating agents. The bubble nucleation points are evenly and densely distributed, easily forming a micro-foamed structure with small and uniformly distributed pore sizes. This eliminates the need for nucleating agents in traditional processes, simplifying the formulation and processing flow, while also reducing the thermal conductivity of the foamed material.

[0041] For example, the preparation process of the modified foaming agent includes: mixing bicarbonate, epoxy resin, pentaerythritol tetramerol ester and dichloromethane, heating to 45-50℃ and holding for 0.5-2h, then adding petroleum ether and triethylamine while stirring and curing at room temperature, filtering, washing, and low-temperature vacuum drying to obtain the modified foaming agent.

[0042] In this invention, pentaerythritol tetramercaptoester can be pentaerythritol tetrakis(3-mercaptopropionic acid) ester (CAS No. 7575-23-7).

[0043] According to the present invention, the bicarbonate can be a conventionally selected bicarbonate in the art, such as sodium bicarbonate, potassium bicarbonate, calcium bicarbonate, etc. To further improve the toughness of the foamed material and reduce its thermal conductivity, preferably, the bicarbonate is sodium bicarbonate and / or potassium bicarbonate, more preferably sodium bicarbonate. There is no particular limitation on the size of the bicarbonate; preferably, the particle size of the bicarbonate is 180-220 mesh.

[0044] According to the present invention, in order to further reduce the thermal conductivity of the foamed material, preferably, the mass ratio of the epoxy resin, the bicarbonate and the pentaerythritol tetramercaptoester is 1:8-12:0.5-0.8.

[0045] According to the present invention, the POE substrate can be a conventionally selected POE substrate in the art. In order to further improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material, preferably, the POE substrate is a polyethylene octene co-elastomer and / or a polyethylene butene co-elastomer.

[0046] According to the present invention, preferably, the melt flow index of the high-impact polystyrene at a temperature of 200°C and a load of 5 kg is 0.5-0.6 g / min, specifically 0.5 g / min, 0.55 g / min, 0.6 g / min, or any value between the two aforementioned values. The inventors have found that, under this preferred embodiment, the foamed material, while improving its toughness and reducing its thermal conductivity, also possesses excellent mechanical and processing properties, and has broad application prospects.

[0047] In this invention, the melt flow index of high-impact polystyrene is tested according to the method in ASTM D-1238 Test Method for Measuring Melt Flow Rate of Thermoplastic Plastics Using an Extrusion Plasticizer.

[0048] According to the present invention, in order to further improve the toughness of the foamed material and reduce its thermal conductivity while improving its service life and stability, preferably, the raw material components of the foamed material also include an antioxidant.

[0049] According to the present invention, in order to further improve the toughness of the foamed material and reduce its thermal conductivity, while improving its service life and stability, the antioxidant to the POE substrate is preferably 0.5-0.8:100 by mass, specifically 0.5:100, 0.65:1, 0.8:100, or any value between the two aforementioned values.

[0050] According to the present invention, preferably, the thermal conductivity of the foamed material is 0.12-0.21 W / (m·K), specifically 0.12 W / (m·K), 0.18 W / (m·K), 0.21 W / (m·K), or any value between the two aforementioned values; the notched impact strength is 18-24 MPa, specifically 18 MPa, 21 MPa, 24 MPa, or any value between the two aforementioned values. The foamed material having the above performance parameters possesses both low thermal conductivity and excellent mechanical properties.

[0051] In this invention, the thermal conductivity of the foamed material is tested according to the standard GB / T 11205-2009 Determination of Thermal Conductivity of Rubber by Hot Wire Method, and the hot wire method for determining the thermal conductivity of rubber in this standard is used; the notched impact strength is tested according to the method in GB / T1843-2008 Determination of Impact Strength of Plastic Cantilever Beam.

[0052] Because the air inside is an excellent insulating medium, the thermal conductivity of the foamed material is significantly reduced. When this foamed material is applied to the inner and outer shells of a refrigerator, it can effectively improve the temperature uniformity inside the refrigerator, enhance the insulation effect, and reduce energy consumption.

[0053] The preparation method of the foamed material in this invention is simple, convenient for industrial production, and has significant economic benefits.

[0054] According to the present invention, in order to further improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material, preferably, the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent and the high-impact polystyrene is 100:3-5:90-100:900-1000.

[0055] According to the present invention, in order to further improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material, preferably, the compatibilizer is SEBS grafted maleic anhydride.

[0056] According to the present invention, in order to further reduce the thermal conductivity of the foaming material, preferably, the preparation process of the modified foaming agent includes: mixing bicarbonate, epoxy resin, pentaerythritol tetramerol ester, dichloromethane, triethylamine and petroleum ether.

[0057] For example, the preparation process of the modified foaming agent includes: mixing bicarbonate, epoxy resin, pentaerythritol tetramerol ester and dichloromethane, heating to 45-50℃ and holding for 0.5-2h, then adding petroleum ether and triethylamine while stirring and curing at room temperature, filtering, washing, and low-temperature vacuum drying to obtain the modified foaming agent.

[0058] According to the present invention, in order to further improve the toughness of the foamed material and reduce its thermal conductivity, preferably, the bicarbonate is sodium bicarbonate and / or potassium bicarbonate, more preferably sodium bicarbonate. There is no particular limitation on the size of the bicarbonate; preferably, the particle size of the bicarbonate is 180-220 mesh.

[0059] According to the present invention, in order to further reduce the thermal conductivity of the foamed material, preferably, the mass ratio of the epoxy resin, the bicarbonate and the pentaerythritol tetramercaptoester is 1:8-12:0.5-0.8.

[0060] According to the present invention, preferably, the solvent is selected from at least one of dichloromethane, triethylamine, and petroleum ether. More preferably, the solvent is dichloromethane, triethylamine, and petroleum ether. Even more preferably, the amount of dichloromethane used is 10-16 mL, the amount of triethylamine used is 0.4-0.8 g, and the amount of petroleum ether used is 20-40 mL, compared to 10 g of the bicarbonate.

[0061] According to the present invention, the POE substrate can be a conventionally selected POE substrate in the art. In order to further improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material, preferably, the POE substrate is a polyethylene octene co-elastomer and / or a polyethylene butene co-elastomer.

[0062] According to the present invention, preferably, the melt flow index of the high-impact polystyrene at a temperature of 200°C and a load of 5 kg is 0.5-0.6 g / min, specifically 0.5 g / min, 0.55 g / min, 0.6 g / min, or any value between the two aforementioned values. The inventors have found that, under this preferred embodiment, the foamed material not only improves the toughness and reduces the thermal conductivity of the foamed material, but also possesses excellent mechanical and processing properties.

[0063] According to the present invention, in order to further improve the mixing effect, preferably, in step (1), the conditions of mixing I include at least: the rotation speed is 500-1000 rpm, specifically 500 rpm, 600 rpm, 800 rpm, 1000 rpm, or any value between the two aforementioned values; the time is 2-10 min, specifically 2 min, 4 min, 6 min, 8 min, 10 min, or any value between the two aforementioned values.

[0064] In this invention, mixing I can be carried out in mixing equipment conventionally selected in the art, such as a mixer.

[0065] According to the present invention, in order to further improve the foaming effect, preferably, the conditions of the extrusion I include at least: a temperature of 180-220°C, specifically 180°C, 190°C, 200°C, 210°C, 220°C, or any value between the two aforementioned values; and a pressure of 2-5 MPa, specifically 2 MPa, 3 MPa, 4 MPa, 5 MPa, or any value between the two aforementioned values.

[0066] According to the present invention, in order to further improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material, while improving the service life and stability of the foamed material, preferably, step (1) further includes: adding an antioxidant during the mixing process I.

[0067] According to the present invention, in order to further improve the toughness of the foamed material and reduce its thermal conductivity, while improving its service life and stability, the antioxidant to the POE substrate is preferably 0.5-0.8:100, specifically 0.5:100, 0.65:100, 0.8:100, or any value between the two aforementioned values.

[0068] In this invention, extrusion I is performed in extrusion equipment conventionally selected in the art. Exemplarily, the extrusion equipment may be a single-screw extruder or a twin-screw extruder.

[0069] According to a particularly preferred embodiment of the present invention, a method for preparing a foamed material is provided, the method comprising the following steps: (1) Mix POE substrate, antioxidant, compatibilizer, high-impact polystyrene and modified foaming agent to obtain mixture A; (2) Extruding mixture A; the mass ratio of POE substrate, compatibilizer, modified foaming agent and high-impact polystyrene is 100:3-5:90-100:900-1000; The compatibilizer is SEBS grafted maleic anhydride; the POE substrate is polyethylene octene co-elastomer and / or polyethylene butene co-elastomer; the melt index of high-impact polystyrene at a temperature of 200℃ and a load of 5kg is 0.5-0.6g / min; the mass ratio of antioxidant to POE substrate is 0.5-0.8:100. The preparation process of the modified foaming agent includes: mixing bicarbonate, epoxy resin, pentaerythritol tetramercaptoester, and dichloromethane, heating to 45-50℃ and maintaining for 0.5-2 hours, then adding petroleum ether and triethylamine while stirring and curing at room temperature, filtering, washing, and low-temperature vacuum drying; the mass ratio of epoxy resin, bicarbonate, and pentaerythritol tetramercaptoester is 1:8-12:0.5-0.8; compared to 10g of bicarbonate, the amount of dichloromethane used is 10-16mL, the amount of triethylamine used is 0.4-0.8g, and the amount of petroleum ether used is 20-40mL; the bicarbonate is sodium bicarbonate and / or potassium bicarbonate.

[0070] The foamed material obtained by the above-mentioned preferred embodiment can effectively improve the toughness of the foamed material and reduce the thermal conductivity of the foamed material through the synergistic effect between the POE substrate, high-impact polystyrene, modified foaming agent and compatibilizer in a specific ratio, without affecting the mechanical properties and processing properties of the foamed material. Moreover, the foamed material is not prone to cracking during processing.

[0071] Thirdly, the present invention provides the application of the foamed material described in the first aspect and / or the foamed material obtained by the preparation method described in the second aspect in plastic products and automotive products.

[0072] Fourthly, the present invention provides a refrigeration liner, which is prepared using the foaming material described in the first aspect and / or the foaming material obtained by the preparation method described in the second aspect.

[0073] The present invention will be described in detail below with reference to embodiments, but this does not limit the scope of the invention.

[0074] In the following examples and comparative examples, the POE substrate was purchased from Guangzhou Hongcheng Plastics Co., Ltd., model ExxonMobil EXACTPOE 9061; the high-impact polystyrene (HIPS) was purchased from Hong Kong Petrochemical Co., Ltd., model standard material; the antioxidant was purchased from BASF, model Irganox 1010; the compatibilizer SEBS-g-MAH was purchased from Kraton, model FG1901; the compatibilizer POE-g-MAH was purchased from Arkema, model HT-1A; the compatibilizer PP-g-MAH was purchased from Hengtai Plastics Co., Ltd., model general-purpose agent; pentaerythritol tetramercaptoester was pentaerythritol tetrakis(3-mercaptopropionic acid) ester, purchased from Shenzhen Bofulong Co., Ltd.; unless otherwise specified, all other raw materials were commercially available.

[0075] Preparation Example 5g of sodium bicarbonate (200 mesh), 0.5g of epoxy resin (Sinopec Baling Petrochemical Branch, model E51), 0.25g of pentaerythritol tetramerol ester, and 5mL of dichloromethane were mixed and stirred to form a uniform suspension. The mixture was then heated to 50℃ and maintained for 1 hour to allow the dichloromethane to evaporate, resulting in moist bicarbonate particles uniformly coated with the epoxy resin and pentaerythritol tetramerol ester mixture. The moist bicarbonate particles were then transferred to 10mL of petroleum ether, and 0.2g of triethylamine was added. The mixture was stirred and cured at room temperature. After 6 hours, samples were taken, filtered, washed, and dried under low-temperature vacuum to obtain the modified foaming agent.

[0076] Example 1 (1) 100 parts of POE substrate (density 0.863 g / cm³, melt index 0.50 g / 10 min, hardness 60 A, glass transition temperature: -58.0 °C), antioxidant, compatibilizer SEBS-g-MAH, HIPS and modified foaming agent obtained in the preparation example were placed in a mixer and stirred for 3 minutes at a stirring speed of 800 rpm to obtain mixture A; (2) The mixture A obtained in step (1) is extruded into a sheet on an extruder at an extrusion temperature of 200℃ and a pressure of 4MPa. The foaming ratio of the sheet is 10%, and a foamed material is obtained. The mass ratio of POE substrate, antioxidant, SEBS-g-MAH, modified foaming agent and high-impact polystyrene is 100:0.75:3:90:900.

[0077] Example 2 (1) 100 parts of POE substrate (density 0.863 g / cm³, melt index 0.50 g / 10 min, hardness 60 A, glass transition temperature: -58.0 °C), antioxidant, compatibilizer SEBS-g-MAH, HIPS and modified foaming agent obtained in the preparation example were placed in a mixer and stirred for 10 minutes at a stirring speed of 500 rpm to obtain mixture A; (2) The mixture A obtained in step (1) is extruded into a sheet on an extruder at an extrusion temperature of 180°C and a pressure of 2MPa. The sheet foaming ratio is 5%, and a foamed material is obtained. The mass ratio of POE substrate, antioxidant, SEBS-g-MAH, modified foaming agent and high-impact polystyrene is 100:0.75:4:95:950.

[0078] Example 3 (1) 100 parts of P0E substrate (density 0.863 g / cm³, melt index 0.50 g / 10 min, hardness 60 A, glass transition temperature: -58.0℃), 0.8 parts of antioxidant 1010, 5 parts of compatibilizer SEBS-g-MAH, 1000 parts of HIPS and 100 parts of modified foaming agent obtained in the preparation example were put into a mixer and stirred for 5 minutes at a stirring speed of 1000 rpm to obtain mixture A; (2) The mixture A obtained in step (1) is extruded into a sheet on an extruder at an extrusion temperature of 220°C and a pressure of 5 MPa. The foaming ratio of the sheet is 20%, and a foamed material is obtained. The mass ratio of POE substrate, antioxidant, SEBS-g-MAH, modified foaming agent and high-impact polystyrene is 100:0.75:5:100:1000.

[0079] Example 4 The foamed material was prepared according to the method of Example 1, except that in step (3), the mass ratio of POE substrate, antioxidant, SEBS-g-MAH, modified foaming agent and high impact polystyrene was 100:0.5:5:80:800.

[0080] Example 5 The foamed material was prepared according to the method of Example 1, except that in step (3), the mass ratio of POE substrate, antioxidant, SEBS-g-MAH, modified foaming agent and high impact polystyrene was 100:0.8:1:100:1000.

[0081] Example 6 The foaming material was prepared according to the method of Example 1, except that in step (1), 3 parts of SEBS-g-MAH were replaced with 3 parts of PP-g-MAH.

[0082] Example 7 The foamed material was prepared according to the method of Example 1, except that in step (1), 3 parts of SEBS-g-MAH were replaced with 3 parts of POE-g-MAH.

[0083] Comparative Example 1 The foamed material was prepared according to the method of Example 1, except that in step (1), the mass ratio of POE substrate, antioxidant, SEBS-g-MAH, modified foaming agent and high impact polystyrene was 100:0.75:8:120:700.

[0084] Comparative Example 2 The foaming material was prepared according to the method of Example 1, except that in step (1), 3 parts of SEBS-g-MAH were not added.

[0085] Comparative Example 3 The foaming material was prepared according to the method of Example 1, except that in step (1), 90 parts of modified foaming agent were replaced with 90 parts of ordinary bicarbonate foaming agent.

[0086] Test case The thermal conductivity, notched impact strength, toughness and cracking of the foamed materials prepared in Examples 1-7 and Comparative Examples 1-3 were tested, and the results are shown in Table 1.

[0087] The thermal conductivity of the foamed material was tested according to the method in GB / T 11205-2009 Determination of Thermal Conductivity of Rubber - Hot Wire Method; the notched impact strength was tested according to the method in GB / T1843-2008 Determination of Impact Strength of Plastic Cantilever Beams; and the tensile strength was tested according to GB / T 1040.1 The tensile properties of plastics shall be tested according to the methods in GB / T 8812.2-2007 Determination of flexural properties of rigid foamed plastics - Part 2: Determination of flexural strength and apparent flexural modulus.

[0088] Table 1

[0089] As can be seen from the results in Table 1, compared with Comparative Examples 1-3, the foamed materials obtained by the preparation method provided by the present invention in Examples 1-7 can effectively improve the toughness of the foamed materials and reduce the thermal conductivity of the foamed materials through the synergistic effect of POE substrate and bicarbonate in a specific ratio. This does not affect the mechanical properties and processing performance of the foamed materials. Moreover, the foamed materials are not prone to cracking during processing, resulting in significant economic benefits.

[0090] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A foaming material, characterized in that, The raw material components of the foaming material include POE substrate, high-impact polystyrene, modified foaming agent and compatibilizer, wherein the compatibilizer is selected from at least one of SEBS grafted maleic anhydride, PP grafted maleic anhydride and POE grafted maleic anhydride; the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent and the high-impact polystyrene is 100:1-5:80-100:800-1000.

2. The foamed material according to claim 1, characterized in that, The mass ratio of the POE substrate, the compatibilizer, the modified foaming agent, and the high-impact polystyrene is 100:3-5:90-100:900-1000; Preferably, the compatibilizer is SEBS grafted maleic anhydride; Preferably, the preparation process of the modified foaming agent includes: mixing bicarbonate, epoxy resin, pentaerythritol tetramercaptoester, dichloromethane, triethylamine and petroleum ether; Preferably, the bicarbonate is sodium bicarbonate and / or potassium bicarbonate; Preferably, the mass ratio of the epoxy resin, the bicarbonate, and the pentaerythritol tetramercaptoester is 1:8-12:0.5-0.

8.

3. The foamed material according to claim 1, characterized in that, The POE substrate is a polyethylene octene co-elastomer and / or a polyethylene butene co-elastomer; Preferably, the high-impact polystyrene has a melt index of 0.5-0.6 g / min at a temperature of 200°C and a load of 5 kg.

4. The foamed material according to any one of claims 1 to 3, characterized in that, The raw material components of the foaming material also include antioxidants; Preferably, the mass ratio of the antioxidant to the POE substrate is 0.5-0.8:

100.

5. The foamed material according to any one of claims 1 to 3, characterized in that, The thermal conductivity of the foamed material is 0.12-0.21 W / (m·K), and the notched impact strength is 18-24 MPa.

6. A method for preparing a foamed material, characterized in that, The method includes the following steps: (1) Mix POE substrate, antioxidant, compatibilizer, high-impact polystyrene and modified foaming agent to obtain mixture A; (2) Extruding the mixture A; The compatibilizer is selected from at least one of SEBS grafted maleic anhydride, PP grafted maleic anhydride, and POE grafted maleic anhydride; the mass ratio of the POE substrate, the compatibilizer, the modified foaming agent, and the high-impact polystyrene is 100:1-5:80-100:800-1000.

7. The preparation method according to claim 6, characterized in that, The mass ratio of the POE substrate, the compatibilizer, the modified foaming agent, and the high-impact polystyrene is 100:3-5:90-100:900-1000; Preferably, the compatibilizer is SEBS grafted maleic anhydride; Preferably, the preparation process of the modified foaming agent includes: mixing bicarbonate, epoxy resin, pentaerythritol tetramercaptoester, dichloromethane, triethylamine and petroleum ether; Preferably, the bicarbonate is sodium bicarbonate and / or potassium bicarbonate; Preferably, the mass ratio of the epoxy resin, the bicarbonate, and the pentaerythritol tetramercaptoester is 1:8-12:0.5-0.8; Preferably, the POE substrate is a polyethylene octene co-elastomer and / or a polyethylene butene co-elastomer; Preferably, the high-impact polystyrene has a melt index of 0.5-0.6 g / min at a temperature of 200°C and a load of 5 kg.

8. The preparation method according to claim 6 or 7, characterized in that, In step (1), preferably, the conditions for mixing I include at least: a rotation speed of 500-1000 rpm and a time of 2-10 min; Preferably, the conditions for extrusion I include at least: a temperature of 180-220°C and a pressure of 2-5 MPa; Preferably, step (1) further includes: adding an antioxidant during the mixing process; Preferably, the mass ratio of the antioxidant to the POE substrate is 0.5-0.8:

100.

9. The use of the foamed material according to any one of claims 1 to 5 and / or the foamed material obtained by the preparation method according to any one of claims 6 to 8 in plastic products and automotive products.

10. A refrigeration equipment inner liner, characterized in that, The inner liner of the refrigeration equipment is prepared using the foaming material described in any one of claims 1 to 5 and / or the foaming material obtained by the preparation method described in any one of claims 6 to 8.

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