Polyamide flame-retardant material as well as preparation method and application thereof
By interposing the bromine flame retardant between the layers of the layered bimetal hydroxide, and using polyamide as the base material, and introducing flame retardant modifiers through composite blending modification technology, the problems of easy decomposition of flame retardant and reduced mechanical strength are solved, and a polyamide flame retardant material with high flame retardant performance and easy cleaning are achieved.
Patent Information
- Application Number
- CN202411724310.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-03-04
AI Technical Summary
Existing flame retardant modified plastics are prone to decomposition in high temperature and high humidity environments, resulting in a degradation of flame retardant performance, and the addition of flame retardant will affect the mechanical strength of the material.
By interleaving the bromine flame retardant between the layers of the layered bimetal hydroxide, and using polyamide as the base material, the flame retardant modifier is introduced through composite blending modification technology to enhance the flame retardant effect of the material.
The flame retardant performance of polyamide flame retardant materials has been significantly improved, the limit oxygen index has been increased by 10%, the vertical combustion level has been increased from V2 to V0, and while ensuring mechanical properties, the easy cleaning of the material has been improved.
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Figure CN119552407A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of flame retardant materials, and specifically relates to a polyamide flame retardant material and a preparation method and application thereof. Background Art
[0002] The range hood is a kitchen appliance that purifies the kitchen environment. It can quickly remove the oil smoke that is harmful to the human body during cooking and discharge it outdoors, reducing indoor pollution. It also has anti-toxic and explosion-proof safety protection functions. The impeller is the key component of the range hood to extract oil smoke. Its main function is to generate negative pressure through rotation to extract the oil smoke generated in the kitchen.
[0003] The materials of range hood impellers are generally divided into two types: metal and plastic. Metal impellers are more durable, but they are noisier than plastic impellers and more expensive. Plastic impellers are relatively quiet and have lower cost materials. Common plastic impeller materials include acrylonitrile-butadiene-styrene copolymer, polypropylene, polyamide thermoplastic polymer materials, etc. Due to the presence of open flames and high temperatures in the cooking environment, most plastic materials in range hoods need to meet non-flammable or flame retardant requirements. For the flame retardant modification of thermoplastic polymers, a flame retardant modifier such as a quantitative halogen flame retardant or phosphorus flame retardant is usually added to the raw materials, and then a flame retardant impeller is obtained through an injection molding process.
[0004] However, for flame-retardant modified plastics prepared directly by blending, on the one hand, due to the poor interfacial compatibility between the flame retardant and the plastic substrate, the organic flame retardant inside the material is easily decomposed and precipitated under high temperature and high humidity conditions, which will directly lead to a decrease in the overall flame retardant performance of the material. On the other hand, the addition of flame retardant materials will directly affect the mechanical strength of the plastic substrate and indirectly affect the flame retardant performance. Summary of the invention
[0005] In order to solve the above technical problems, the present application provides a polyamide material with good flame retardant effect, which is specifically achieved through the following technical solutions:
[0006] The first purpose of the present application is to propose a method for preparing a polyamide flame retardant material, comprising the following steps: S1, inserting a bromine flame retardant between the layers of a layered double metal hydroxide to obtain a flame retardant modifier; S2, by mass percentage, 50-70wt% polyamide, 1-7wt% flame retardant modifier, 0.3-4wt% first antioxidant, 0.5-4wt% toughening agent, 0.5-5wt% compatibilizer and 20-30wt% reinforcing agent are mixed, extruded and granulated to obtain a polyamide flame retardant material. Specifically, the bromine flame retardant includes one or more of decabromodiphenyl ether (DBDPO), tetrabromobisphenol A (TBBPA), and decabromodiphenyl ethane (DBDPE). The antioxidant includes one or more of tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, N,N'-1,6-hexylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 3,5-di-tert-butyl-4-hydroxyphenylpropionic acid n-octadecyl alcohol, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)trione, triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). The toughening agent includes one or more of ethylene-propylene copolymer, ethylene-hexene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, styrene-butadiene-styrene copolymer, and hydrogenated styrene-butadiene-styrene copolymer. The compatibilizer includes EVA (ethylene-vinyl acetate copolymer), EPDM (ethylene-propylene-diene monomer copolymer), and SEBS (styrene-ethylene-butadiene-styrene copolymer). The reinforcing agent refers to one or more of glass fiber, ultra-high molecular weight polyethylene fiber, and basalt fiber. The reinforcing agent includes glass fiber.
[0007] This technical solution can intercalate brominated flame retardants into the interlayers of layered double hydroxides (LDH) through intercalation design. Since LDH has a high specific surface area and adjustable interlayer spacing, it provides more dispersion space for brominated flame retardants, which helps to improve the uniformity of dispersion of brominated flame retardants between the LDH plate skeletons and avoid their aggregation and sedimentation. This not only improves the overall stability and performance of the flame retardant modifier, but also helps to solve the technical problem that brominated flame retardants are easy to precipitate. Furthermore, this technical solution also uses polyamide as the substrate, introduces flame retardant modifiers through composite blending modification technology, and effectively improves the flame retardant effect of polyamide. Under high temperature conditions, LDH in polyamide flame retardant materials plays a role in diluting oxygen and reducing the surface temperature of the polymer by releasing interlayer bound water and carbon dioxide. In addition, the metal hydroxide of the LDH plate layer undergoes a special catalytic reaction with the polymer during the combustion and degradation process, forming a dense carbon layer on the surface of the composite material, thereby effectively isolating external heat and oxygen from penetrating into the polymer, and slowing down the mass loss rate of the polymer during thermal degradation. The brominated flame retardant in the flame retardant modifier can capture active free radicals in the combustion process in the gas phase, effectively slowing down or terminating the combustion reaction.
[0008] Preferably, the preparation method of the polyamide flame retardant material further comprises the following steps: S3, subjecting the polyamide flame retardant material to a free radical polymerization reaction with a free radical polymerization initiator, a second antioxidant and a mixture of vinyl alcohol monomers to obtain a surface-treated polyamide flame retardant material. The free radical polymerization initiator comprises one or more of benzoyl peroxide (BPO), diisopropylbenzene peroxide (DCP), 2,3-dimethyl 2,3-diphenylbutane (DMDPB), and acrylamide (AM). The second antioxidant is one or more of naphthylamine, diphenylamine, and p-phenylenediamine.
[0009] This technical solution can give the material excellent anti-fouling and easy-to-clean effects by grafting the hydroxyl groups on the surface of the polyamide flame retardant material, and finally prepare a flame retardant and easy-to-clean polyamide flame retardant material. Specifically, the abundant hydroxyl (-OH) groups on the PVA molecular chain can form hydrogen bonds with water molecules, making the surface of the PVA material highly hydrophilic. This hydrophilicity allows water to wet the PVA surface, thereby reducing the surface tension, facilitating the spreading of water and detergents on the surface of the material, and taking away the attached dirt. In addition, the molecular chain of PVA has a certain degree of flexibility and can be deformed under the action of external forces, which helps to reduce the contact area between the dirt and the material surface and further promote the cleaning effect. At the same time, the intermolecular force of PVA is relatively weak, which makes it difficult for dirt to adhere firmly to the PVA surface and is easier to be washed off.
[0010] Preferably, the intercalation method in step S1 comprises: subjecting a soluble divalent metal salt, a soluble trivalent metal salt, an intercalation agent and a brominated flame retardant to a hydrothermal reaction in an alkaline environment. In step S1, the divalent cation in the soluble divalent and trivalent metal salt solution is Cu 2+ 、Zn 2+ 、Ni 2+ Mg 2+ Any of the following, the trivalent cation is Fe 3+ 、Al 3+ Any one of the following; the anion in the soluble divalent metal salt or soluble trivalent metal salt solution is NO 3- 、SO4 2- The intercalant is sodium dodecyl sulfate or sodium dodecylbenzene sulfonate. The alkaline environment refers to the addition of one or more of urea, ammonia or sodium hydroxide.
[0011] This technical solution successfully intercalates the brominated flame retardant into the interlayers of layered double hydroxides (LDH) by hydrothermally reacting a mixture of a soluble divalent metal salt, a soluble trivalent metal salt, an intercalant and a brominated flame retardant in an alkaline environment.
[0012] Preferably, the raw materials for preparing the flame retardant modifier include, by weight: 100 parts of soluble divalent metal salt, 20 to 70 parts of soluble trivalent metal salt, 10 to 30 parts of intercalant and 20 to 40 parts of brominated flame retardant. Further preferably, the raw materials for preparing the flame retardant modifier include, by weight: 100 parts of soluble divalent metal salt, 20 parts of soluble trivalent metal salt, 10 parts of intercalant and 30 parts of brominated flame retardant.
[0013] Preferably, the hydrothermal reaction conditions are a temperature of 60 to 110° C., a time of 10 to 24 h, and a pH of 7 to 10.
[0014] Preferably, before the mixed extrusion granulation in step S2, the polyamide, the flame retardant modifier, the first antioxidant, the toughening agent, the compatibilizer and the reinforcing agent are respectively subjected to vacuum drying treatment.
[0015] Preferably, in step S3, calculated by weight, the polyamide flame retardant material is 100 parts, the free radical polymerization initiator is 2 parts, the second antioxidant is 0.7 parts, and the vinyl alcohol monomer is 5 to 15 parts.
[0016] Preferably, the reaction conditions of the free radical polymerization are: temperature 50-80° C., and reaction time 3-6 h.
[0017] The second objective of the present application is to provide a polyamide flame retardant material prepared by any of the preparation methods described above.
[0018] The third objective of the present application is to propose the use of any of the polyamide flame retardant materials described above in kitchen appliances.
[0019] The so-called kitchen equipment not only includes equipment with flame retardant and easy-to-clean requirements such as range hoods, stoves, dishwashers, and water purifiers, but also includes certain components of the kitchen equipment. Taking the range hood as an example, components such as impellers and air ducts can adopt the polyamide flame retardant material of the present application.
[0020] Compared with the prior art, this application has the following beneficial effects:
[0021] This application successfully prepared a polyamide flame retardant material with high flame retardant properties by combining bromine flame retardant intercalation technology with composite blending modification technology. Performance tests show that the limiting oxygen index of this application is 10% higher than that of the polyamide blank group, and the vertical combustion level is increased from V2 to V0, which shows that it has excellent flame retardancy. Although the addition of bromine flame retardant materials in this application will affect the tensile strength of the material, the overall mechanical properties of the material are still guaranteed, and the flame retardant properties of polyamide flame retardant materials can be indirectly improved by maintaining the thermal integrity of the material's structure. This application introduces grafting technology and verifies it through single-factor experiments. It is found that after adopting grafting technology, the limiting oxygen index can be further improved by 2% on the basis of the above-mentioned limit oxygen index. This shows that grafting technology can cooperate with intercalation technology and composite blending modification technology to jointly improve the flame retardant properties of polyamide flame retardant materials.
[0022] This application controls the amount of flame retardant modifier added to the raw materials for preparing polyamide flame retardant materials, and can cooperate with grafting technology to further reduce the water contact angle and improve the easy cleaning of polyamide flame retardant materials under the premise of ensuring the flame retardant properties and mechanical properties of polyamide flame retardant materials. The applicant found that the amount of flame retardant modifier added is closely related to the size of the water contact angle. After the polyamide material is simply grafted with PVA, the water contact angle will drop significantly; however, when the PVA grafting treatment is applied to the polyamide flame retardant material treated with the bromine flame retardant intercalation technology and the composite blending modification technology, the situation is different, which is specifically reflected in the water contact angle compared to the polyamide material. The rebound shows a large rebound. The applicant not only solves the above-mentioned rebound problem by adjusting the amount of flame retardant modifier added to the polyamide flame retardant material, but also finds that the water contact angle is further reduced after performance testing. It can be seen that the grafting technology can not only cooperate with the intercalation technology and the composite blending modification technology to jointly improve the flame retardant properties of the polyamide flame retardant material, but also cooperate to improve the easy cleaning of the material. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to clearly introduce the embodiments, the drawings of the accompanying drawings are briefly introduced below:
[0024] Figure 1This is a flow chart of the preparation of the polyamide flame retardant material in Example 1 of the present application;
[0025] Figure 2 This is a flow chart for preparing the polyamide flame retardant material of Example 2 of the present application. DETAILED DESCRIPTION
[0026] The present application will be further described below in the form of specific embodiments. Those of ordinary skill in the art will be able to implement the present application based on these descriptions. In addition, the embodiments of the present application involved in the following description are generally only embodiments of a part of the present application, rather than all embodiments. Therefore, based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present application.
[0027] Example 1
[0028] This embodiment discloses a method for preparing a polyamide flame retardant material, which specifically comprises the following steps:
[0029] S1. Based on 100 parts by mass of divalent metal salt, add CuSO4 (100 parts by mass), Al2(SO4)3 (20 parts by mass), sodium dodecylbenzene sulfonate (10 parts by mass), DBDPO (30 parts by mass), and urea (50 parts by mass) into 5000 parts by mass of distilled water. The mixture was stirred continuously at 60°C and pH = 7 for 10 hours for hydrothermal reaction. After the reaction, the product was filtered to obtain the product, and washed with a large amount of distilled water. Finally, the flame retardant modifier SDBS-O was obtained after vacuum drying for 12 hours. Br FR-LDH.
[0030] S2, polyamide (PA6), flame retardant modifier SDBS-O Br FR-LDH, glass fiber, first antioxidant (tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester), toughening agent (ethylene-propylene copolymer), compatibilizer (EVA (ethylene-vinyl acetate copolymer)) are vacuum dried at 40-100°C for 1-0h, 70wt% polyamide, 7wt% flame retardant modifier SDBS-OBrFR-LDH, 2wt% first antioxidant, 2wt% toughening agent, 4wt% compatibilizer and 15wt% glass fiber are mixed in a high-speed mixer for 2-10min, the mixed material is added from the main material port, extruded and granulated by an extruder, the speed of the screw extruder is 100rpm, the temperature of the feeding section is 220°C, the three-section temperatures of the screw center are 240°C, 265°C, 250°C, and the die head temperature is 190°C, and finally a polyamide flame retardant material is obtained.
[0031] S3. Put polyamide flame retardant material, methanol and water in a reaction vessel with a mass feed ratio of 1:7:15. Based on 100 parts by mass of polyamide flame retardant material, add vinyl alcohol monomer, free radical polymerization initiator (benzoyl peroxide) and second antioxidant (diphenylamine) in a mass feed ratio of 8:2:0.7 respectively. Start stirring and slowly heat to 60°C under nitrogen to perform free radical polymerization reaction. After reacting for 3 hours, wash and dry with ethanol solution, that is, prepare antifouling and easy-to-clean graft modification of PVA on the surface of polyamide flame retardant material.
[0032] Example 2
[0033] This embodiment discloses a method for preparing a polyamide flame retardant material, which specifically comprises the following steps:
[0034] S1. Based on 100 parts by mass of divalent metal salt, add CuSO4 (100 parts by mass), Al2(SO4)3 (20 parts by mass), sodium dodecylbenzene sulfonate (10 parts by mass), DBDPO (30 parts by mass), and urea (50 parts by mass) into 5000 parts by mass of distilled water. The mixture was stirred continuously at 60°C and pH = 7 for 10 hours for hydrothermal reaction. After the reaction, the product was filtered to obtain the product, and washed with a large amount of distilled water. Finally, the flame retardant modifier SDBS-O was obtained after vacuum drying for 12 hours. Br FR-LDH.
[0035] S2, polyamide (PA6), flame retardant modifier SDBS-O Br FR-LDH, glass fiber, first antioxidant (tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester), toughening agent (ethylene-propylene copolymer), compatibilizer (EVA (ethylene-vinyl acetate copolymer)) are vacuum dried at 40-100°C for 1-0h, 70wt% polyamide, 7wt% flame retardant modifier SDBS-OBrFR-LDH, 2wt% first antioxidant, 2wt% toughening agent, 4wt% compatibilizer and 15wt% glass fiber are mixed in a high-speed mixer for 2-10min, the mixed material is added from the main material port, extruded and granulated by an extruder, the speed of the screw extruder is 100rpm, the temperature of the feeding section is 220°C, the three-section temperatures of the screw center are 240°C, 265°C, 250°C, and the die head temperature is 190°C, and finally a polyamide flame retardant material is obtained.
[0036] Example 3
[0037] This embodiment discloses a method for preparing a polyamide flame retardant material, which specifically comprises the following steps:
[0038] S1. Based on 100 parts by mass of divalent metal salt, add CuSO4 (100 parts by mass), Al2(SO4)3 (70 parts by mass), sodium dodecyl sulfate (30 parts by mass), and DBDPO (20 parts by mass) into 5000 parts by mass of distilled water. The mixture is stirred continuously for hydrothermal reaction at 110°C and pH = 10 (with urea added) for 10 hours. After the reaction, the product is filtered to obtain the product, washed with a large amount of distilled water, and finally dried in vacuum for 12 hours to obtain the flame retardant modifier SDS-O. Br FR-LDH.
[0039] S2, take polyamide (PA6), flame retardant modifier SDS-O Br FR-LDH, glass fiber, first antioxidant (tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester), toughening agent (ethylene-propylene copolymer), compatibilizer (EVA (ethylene-vinyl acetate copolymer)) are vacuum dried at 40-100°C for 1-10h, 50wt% polyamide, 7wt% flame retardant modifier SDS-OBrFR-LDH, 4wt% first antioxidant, 4wt% toughening agent, 5wt% compatibilizer and 30wt% glass fiber are mixed in a high-speed mixer for 2-10min, the mixed material is added from the main material port, extruded and granulated by an extruder, the speed of the screw extruder is 100rpm, the temperature of the feeding section is 220°C, the three-section temperatures of the screw center are 240°C, 265°C, 250°C, and the die head temperature is 190°C, and finally a polyamide flame retardant material is obtained.
[0040] S3. Put polyamide flame retardant material, methanol and water in a reaction vessel with a mass feed ratio of 1:7:15. Based on 100 parts by mass of polyamide flame retardant material, add vinyl alcohol monomer, free radical polymerization initiator (benzoyl peroxide) and second antioxidant (diphenylamine) in a mass feed ratio of 15:2:0.7 respectively. Start stirring and slowly heat to 80°C under nitrogen to perform free radical polymerization reaction. After reacting for 3 hours, wash and dry with ethanol solution, that is, prepare antifouling and easy-to-clean graft modification of PVA on the surface of polyamide flame retardant material.
[0041] Example 4
[0042] This embodiment discloses a method for preparing a polyamide flame retardant material, which specifically comprises the following steps:
[0043] S1. Based on 100 parts by mass of divalent metal salt, add CuSO4 (100 parts by mass), Al2(SO4)3 (20 parts by mass), sodium dodecyl sulfate (10 parts by mass), and DBDPO (40 parts by mass) into 5000 parts by mass of distilled water. The mixture is stirred continuously at 100°C and pH = 8 (with urea added) for 24 hours for hydrothermal reaction. After the reaction, the product is filtered to obtain the product, washed with a large amount of distilled water, and finally dried in vacuum for 12 hours to obtain the flame retardant modifier SDS-O. Br FR-LDH.
[0044] S2, take polyamide (PA6), flame retardant modifier SDS-O Br FR-LDH, glass fiber, first antioxidant (tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester), toughening agent (ethylene-propylene copolymer), compatibilizer (EVA (ethylene-vinyl acetate copolymer)) are vacuum dried at 40-100°C for 1-10h, 70wt% polyamide, 1wt% flame retardant modifier SDS-OBrFR-LDH, 0.3wt% first antioxidant, 0.5wt% toughening agent, 0.5wt% compatibilizer and 27.7wt% glass fiber are mixed in a high-speed mixer for 2-10min, the mixed material is added from the main material port, extruded and granulated by an extruder, the speed of the screw extruder is 100rpm, the temperature of the feeding section is 220°C, the temperatures of the three sections in the center of the screw are 240°C, 265°C and 250°C, the temperature of the die head is 190°C, and finally a polyamide flame retardant material is obtained.
[0045] S3. Put polyamide flame retardant material, methanol and water in a reaction vessel with a mass feed ratio of 1:7:15. Based on 100 parts by mass of polyamide flame retardant material, add vinyl alcohol monomer, free radical polymerization initiator (benzoyl peroxide) and second antioxidant (diphenylamine) in a mass feed ratio of 5:2:0.7 respectively. Start stirring and slowly heat to 50°C under nitrogen to perform free radical polymerization reaction. After 6 hours of reaction, wash and dry with ethanol solution, that is, prepare antifouling and easy-to-clean graft modification of PVA on the surface of polyamide flame retardant material.
[0046] Example 5
[0047] This embodiment discloses a method for preparing a polyamide flame retardant material, which specifically comprises the following steps:
[0048] S1. Based on 100 parts by mass of divalent metal salt, add CuSO4 (100 parts by mass), Al2(SO4)3 (20 parts by mass), sodium dodecyl sulfate (10 parts by mass), DBDPO (30 parts by mass), and urea (50 parts by mass) into 5000 parts by mass of distilled water. The mixture was stirred continuously at 60°C and pH = 7 for 10 hours for hydrothermal reaction. After the reaction, the product was filtered to obtain the product, and washed with a large amount of distilled water. Finally, the flame retardant modifier SDS-O was obtained after vacuum drying for 12 hours. Br FR-LDH.
[0049] S2, take polyamide (PA6), flame retardant modifier SDS-O Br FR-LDH, glass fiber, first antioxidant (tetrakis[methyl-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester), toughening agent (ethylene-propylene copolymer), compatibilizer (EVA (ethylene-vinyl acetate copolymer)) are vacuum dried at 40-100°C for 1-10h, 68wt% polyamide, 2wt% flame retardant modifier SDS-OBrFR-LDH, 2wt% first antioxidant, 3wt% toughening agent, 5wt% compatibilizer and 20wt% glass fiber are mixed in a high-speed mixer for 2-10min, the mixed material is added from the main material port, extruded and granulated by an extruder, the speed of the screw extruder is 100rpm, the temperature of the feeding section is 220°C, the three-section temperatures of the screw center are 240°C, 265°C, 250°C, and the die head temperature is 190°C, and finally a polyamide flame retardant material is obtained.
[0050] S3. Put polyamide flame retardant material, methanol and water in a reaction vessel with a mass feed ratio of 1:7:15. Based on 100 parts by mass of polyamide flame retardant material, add vinyl alcohol monomer, free radical polymerization initiator (benzoyl peroxide) and second antioxidant (diphenylamine) in a mass feed ratio of 8:2:0.7 respectively. Start stirring and slowly heat to 60°C under nitrogen to perform free radical polymerization reaction. After reacting for 3 hours, wash and dry with ethanol solution, that is, prepare antifouling and easy-to-clean graft modification of PVA on the surface of polyamide flame retardant material.
[0051] Comparative Example 1
[0052] The difference between the preparation process of the polyamide flame retardant material in this comparative example and that in Example 1 is that: Step S1: flame retardant modifier SDBS-0 Br During the preparation of FR-LDH, DBDPO was not added, so the flame retardant modifier used in this comparative example was SDBS-LDH.
[0053] Comparative Example 2
[0054] The difference between the preparation process of the polyamide flame retardant material in this comparative example and that in Example 1 is that step S1 and step S3 are not included, and the flame retardant modifier SDBS-0 is not added in step S2. Br FR-LDH.
[0055] Comparative Example 3
[0056] The difference between the preparation process of the polyamide flame retardant material in this comparative example and that in Example 1 is that: Step S1: flame retardant modifier SDBS-0 Br During the preparation of FR-LDH, the amount of DBDPO added was 50 parts.
[0057] Comparative Example 4
[0058] The difference between the preparation process of the polyamide flame retardant material in this comparative example and that in Example 1 is that it only includes step S3, and the polyamide flame retardant material is polyamide.
[0059] Comparative Example 5
[0060] The difference between the preparation process of the polyamide flame retardant material in this comparative example and that in Example 1 is that in step S2, the flame retardant modifier SDBS-0 Br The addition amount of FR-LDH is 10wt%, and the addition amount of polyamide is 67wt%.
[0061] Performance Testing
[0062] This performance test tests the limiting oxygen index, vertical combustion performance, hydrophilicity and tensile strength of the polyamide flame retardant materials prepared in Examples 1 and 2 and Comparative Examples 1 to 5. Specifically, the limiting oxygen index is tested in accordance with the provisions of GB / 8624-2012; the vertical combustion performance is tested in accordance with the provisions of "Flame Retardant Performance Test Method-Vertical Combustion Method" (GB2409-84); the hydrophilicity is tested in accordance with the provisions of GB / T 24368-2009; and the tensile strength is tested in accordance with the provisions of GB / T 1040. The integrated table is as follows:
[0063] Table 1. Performance parameters
[0064]
[0065] From the flame retardant performance point of view, the experimental results of Example 2 and the blank group of Comparative Example 2 show that the present invention prepares the flame retardant modifier SDBS-0 by intercalating the brominated flame retardant between the layered double metal hydroxide layers. Br FR-LDH, with polyamide as the base material, introduces flame retardant modifier SDBS-O through composite blending modification technology BrFR-LDH, the obtained polyamide flame retardant material has high flame retardant performance. Specifically, the limiting oxygen index of the polyamide flame retardant material in Example 1 is increased by 10% compared with the polyamide blank group in Comparative Example 2, and the vertical combustion level is increased from V2 to V0, which shows that it has excellent flame retardancy. Although the addition of bromine-based flame retardant materials in this application will affect the tensile strength of the material, the overall mechanical properties of the material are still guaranteed, and the flame retardant properties of the polyamide flame retardant material can be indirectly improved by maintaining the structural thermal integrity of the material. Furthermore, by comparing Examples 1 and 2 with Comparative Example 2, it can be found that, by finally using grafting technology, PVA is grafted to the surface of the polyamide flame retardant material, which can further increase the limiting oxygen index of Example 1 by 2%, which shows that grafting technology can cooperate with intercalation technology and composite blending modification technology to jointly improve the flame retardant properties of polyamide flame retardant materials.
[0066] From the perspective of surface cleanability, Comparative Example 4 shows that after PVA grafting on polyamide material, its water contact angle decreases from 65° in Comparative Example 2 to 16°, which shows that PVA grafting can solve the technical problem of difficult cleaning of polyamide surface. However, since the polyamide flame retardant material of the present application is different from polyamide material, the bromine flame retardant intercalation technology and the composite blending modification technology give it special properties. Therefore, in Comparative Example 5, only 3wt% of the flame retardant modifier SDBS-O is added. Br The water contact angle increased by more than one time compared with Example 1 by adjusting the amount of FR-LDH added. Br The addition amount of FR-LDH can cooperate with grafting technology, intercalation technology and composite blending modification technology to jointly reduce the water contact angle of polyamide flame retardant materials and increase the cleanability of the materials.
[0067] In addition, the experimental results of Example 1 and Comparative Example 3 show that when a large amount of brominated flame retardants are added, the mechanical properties of the polyamide flame retardant material will be greatly affected. Specifically, compared with Example 1, Comparative Example 3 adds 20 more brominated flame retardants, and its limiting oxygen index, vertical combustion level and water contact angle are basically unchanged, while the tensile strength is reduced by 22Mpa compared with Example 1. This reversely confirms that the present application can cooperate with other raw materials to achieve reasonable control of tensile strength under the premise of ensuring flame retardancy and easy cleaning by designing the addition ratio of brominated flame retardants in the flame retardant modifier, and the material has good mechanical properties, which indirectly improves the flame retardant properties of the material.
Claims
1. A method for preparing a polyamide flame retardant material, characterized in that: The following steps are involved: S1, intercalating a brominated flame retardant between layers of a layered double metal hydroxide to obtain a flame retardant modifier; S2. Calculated by mass percentage, 50-70wt% of polyamide, 1-7wt% of flame retardant modifier, 0.3-4wt% of first antioxidant, 0.5-4wt% of toughening agent, 0.5-5wt% of compatibilizer and 20-30wt% of reinforcing agent are mixed, extruded and granulated to obtain a polyamide flame retardant material.
2. The method for preparing a polyamide flame retardant material according to claim 1, characterized in that: The following steps are also included: S3, subjecting the polyamide flame retardant material to a free radical polymerization reaction with a free radical polymerization initiator, a second antioxidant and a vinyl alcohol monomer mixture to obtain a surface-treated polyamide flame retardant material.
3. The method for preparing a polyamide flame retardant material according to claim 1, characterized in that: Step S1: the intercalation method comprises: subjecting a soluble divalent metal salt, a soluble trivalent metal salt, an intercalation agent and a bromine flame retardant to a hydrothermal reaction in an alkaline environment.
4. The method for preparing a polyamide flame retardant material according to claim 3, characterized in that: Calculated by weight, the raw materials for preparing the flame retardant modifier include: 100 parts of soluble divalent metal salt, 20 to 70 parts of soluble trivalent metal salt, 10 to 30 parts of intercalating agent and 20 to 40 parts of brominated flame retardant.
5. The method for preparing a polyamide flame retardant material according to claim 4, characterized in that: Calculated by weight, the raw materials for preparing the flame retardant modifier include: 100 parts of soluble divalent metal salt, 20 parts of soluble trivalent metal salt, 10 parts of intercalating agent and 30 parts of brominated flame retardant.
6. The method for preparing a polyamide flame retardant material according to claim 1, characterized in that: Before the mixed extrusion granulation in step S2, the polyamide, the flame retardant modifier, the first antioxidant, the toughening agent, the compatibilizer and the reinforcing agent are vacuum dried.
7. The method for preparing a polyamide flame retardant material according to claim 2, characterized in that: In step S3, the polyamide flame retardant material is 100 parts, the free radical polymerization initiator is 2 parts, the second antioxidant is 0.7 parts, and the vinyl alcohol monomer is 5 to 15 parts, calculated by weight.
8. The method for preparing a polyamide flame retardant material according to claim 2 or 7, characterized in that: The reaction conditions of free radical polymerization are: temperature 50-80°C and reaction time 3-6h.
9. The polyamide flame retardant material prepared by the preparation method according to any one of claims 1 to 8.
10. Use of the polyamide flame retardant material according to claim 9 in kitchen equipment.