Polyhexamethylene adipamide flame-retardant material as well as preparation method and application thereof
By interposing a phosphorus-based flame retardant between layers of layered bimetallic hydroxide, and using polyadipylhexyldiamine as the base material, polyadipylhexyldiamine flame retardant materials with excellent flame retardant properties were prepared through composite blending and modification technology, which solved the problem of poor flame retardant effects of existing materials in high-temperature environments, and while ensuring mechanical properties, the easy cleaning of the material is improved.
Patent Information
- Application Number
- CN202411724312.7
- 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 plastic impellers may decompose or precipitate in high temperature environments, reducing the flame retardant effect, and the introduction of flame retardant may weaken the physical properties of the material, such as mechanical strength.
By intercalating the phosphorus-based flame retardant between the layers of layered bimetal hydroxide, an efficient flame retardant modifier was prepared, and polyadipanyl hexanediamine was used as the substrate. Through the composite blending modification technology, the flame retardant modifier was evenly dispersed in the substrate to enhance the flame retardant effect.
The flame retardant performance of polyadipylhexanediamine flame retardant materials has been significantly improved, the limit oxygen index has been increased by 10%, and the vertical combustion level has been increased from V2 to V0, while ensuring mechanical properties, it has improved the easy cleaning of the material.
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Figure CN119552501A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of flame retardant materials, and specifically relates to a polyhexamethylene adipamide flame retardant material and a preparation method and application thereof. Background Art
[0002] The range hood is an important appliance used to purify the air in the kitchen. It can effectively remove the fumes generated during cooking. By quickly extracting the fumes and discharging them outdoors, the range hood not only reduces indoor pollution, but also provides safety protection measures such as anti-poisoning and explosion-proofing. The core of this process lies in the impeller device inside it. The impeller generates negative pressure through high-speed rotation, thereby achieving the extraction of fumes.
[0003] In terms of design, the impellers of range hoods are mostly made of metal or plastic. Metal impellers are known for their durability and stability, but they are more expensive to manufacture and produce more noise during operation. In contrast, plastic impellers are popular due to their lower cost and lower noise. Common materials for plastic impellers include thermoplastic polymers such as acrylonitrile butadiene styrene (ABS), polypropylene (PP) and polyamide (PA). Given the high temperature conditions in the kitchen environment, these plastic materials must meet non-flammable or flame-retardant standards to ensure safety.
[0004] In order to make these plastics flame retardant, an appropriate amount of halogen or phosphorus flame retardants are usually added to the raw materials during the production process, and then the impeller products that meet safety standards are manufactured through injection molding technology. However, this method also brings some challenges. First, due to the poor compatibility between the flame retardant and the plastic matrix, the material may decompose or precipitate in a hot and humid environment, thereby reducing the overall flame retardant effect of the material. Secondly, the introduction of flame retardants may weaken the physical properties of the plastic matrix, such as mechanical strength, which will not only affect the service life of the product, but also indirectly affect the flame retardant performance. Summary of the invention
[0005] In order to solve the above technical problems, the present application provides a flame retardant material of polyhexamethylene adipamide with good flame retardancy, 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 polyhexamethylene adipamide flame retardant material, comprising the following steps: S1, inserting a phosphorus-based flame retardant between the layers of a layered double metal hydroxide to obtain a flame retardant modifier; S2, by mass percentage, mixing 70-95wt% polyhexamethylene adipamide, 1-7wt% flame retardant modifier, 0.3-4wt% first antioxidant, 0.5-4wt% toughening agent, 0.5-5wt% compatibilizer and 2-20wt% reinforcing agent, extruding and granulating to obtain a polyhexamethylene adipamide flame retardant material. In step S1, the phosphorus-based flame retardant includes one or more of 2-carboxyethylphenylphosphinic acid (CEPPA), methylphenylphosphinate (HMPPA), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). In step S2, the first 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-octadecanol, 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 one or more of EVA (ethylene-vinyl acetate copolymer), EPDM (ethylene-propylene-diene monomer copolymer), and SEBS (styrene-ethylene-butadiene-styrene copolymer). The reinforcing agent includes glass fiber.
[0007] This technical solution can intercalate phosphorus-based 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 phosphorus-based flame retardants, which helps to improve the uniformity of dispersion of phosphorus-based 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 phosphorus-based flame retardants are easy to precipitate. Furthermore, this technical solution uses polyhexamethylene adipamide (PA66) as the base material, and introduces flame retardant modifiers through composite blending modification technology, which effectively improves the flame retardant effect of PA66. Under high temperature conditions, LDH in polyhexamethylene adipamide 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 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 interior of the polymer, and slowing down the mass loss rate of the polymer during thermal degradation. The phosphorus-based flame retardant in the flame retardant modifier can quickly generate phosphoric acid or polyphosphoric acid during the combustion process. These substances can cooperate with the catalytic reaction of the LDH plate layer to accelerate the formation of a carbon layer on the surface of the composite material. The present application also achieves the controllability of mechanical properties while ensuring the flame retardant properties of the material by controlling the amount of phosphorus-based flame retardant added during the preparation of polyhexamethylene adipamide flame retardant materials.
[0008] Preferably, the method for preparing the polyhexamethylene adipamide flame retardant material further comprises: S3, subjecting the polyhexamethylene adipamide flame retardant material to a free radical polymerization reaction with a free radical polymerization initiator, a second antioxidant and a betaine type zwitterionic monomer mixture to obtain a surface treated polyhexamethylene adipamide flame retardant material. In step S3, the free radical polymerization initiator is one of benzoyl peroxide (BPO), diisopropyl peroxide (DCP), 2,3-dimethyl 2,3-diphenylbutane (DMDPB), and acrylamide (AM); the second antioxidant is one of naphthylamine, diphenylamine, and p-phenylenediamine; the betaine type zwitterionic monomer is one of sulfobetaine methacrylate (SBMA), methacryloyloxyethyl-N,N-diethylpropane sulfonate (DEPS), 3-[[2-(methacryloyloxy)ethyl]dimethylammonium]propionate (CBMA), 3-(methacrylamido)propyl-dimethyl(3-sulfonic acid)ammonium hydroxide (MPDSAH), and N,N-dimethyl N-(2-methacryloyloxyethyl)N-(3-sulfopropyl)ammonium (DMMSA).
[0009] This technical solution uses atom transfer radical polymerization (ATRP) technology to graft betaine-type zwitterionic polymers onto the surface of polyhexamethylene adipamide flame retardant materials, significantly improving the material's easy-to-clean properties. Betaine-type zwitterionic polymer molecules contain the same number of positive and negatively charged groups, and their molecular chains contain a large number of charged hydrophilic groups, which can bind a large number of water molecules through electrostatic action to form a hydration layer around them. This hydration layer forms an energy barrier on the surface of polyhexamethylene adipamide flame retardant materials, similar to a brush-like antibacterial and antifouling protective layer, thereby effectively preventing the nonspecific adsorption of bacteria, microorganisms and proteins.
[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 phosphorus 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 phosphorus-based flame retardant into the interlayers of a layered double hydroxide (LDH) by hydrothermally reacting a mixture of a soluble divalent metal salt, a soluble trivalent metal salt, an intercalant and a phosphorus-based 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 phosphorus 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 phosphorus 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 polyhexamethylene adipamide, 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 polyhexamethylene adipamide flame retardant material is 100 parts, the free radical polymerization initiator is 2 parts, the second antioxidant is 0.7 parts, and the betaine type zwitterionic monomer is 5 to 15 parts.
[0016] Preferably, the reaction conditions of free radical polymerization are: temperature 30-60° C., and reaction time 3-6 h.
[0017] The second purpose of the present application is to provide a flame retardant polyhexamethylene adipamide material prepared by the above preparation method.
[0018] The third objective of the present application is to propose the application of the above-mentioned polyhexamethylene adipamide flame retardant material in kitchen equipment.
[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 the impeller and the air duct can adopt the polyhexamethylene adipamide flame retardant material of the present application.
[0020] Compared with the prior art, this application has the following beneficial effects:
[0021] The present invention prepares an efficient flame retardant modifier by first inserting a phosphorus-based flame retardant into the interlayer of a layered double metal hydroxide. Then, using polyhexamethylene adipamide as a substrate, the flame retardant modifier is evenly dispersed in the substrate using a composite blending modification technology, and a new polyhexamethylene adipamide flame retardant material with excellent flame retardant properties is successfully developed. The experimental results show that the limiting oxygen index of the material is increased by 10% compared with the unmodified polyhexamethylene adipamide, and the vertical combustion level is increased from V2 to V0, which proves its excellent flame retardant effect. Although the addition of phosphorus-based flame retardants may have a certain impact on the tensile strength of the material, the overall mechanical properties are still guaranteed. This is because the technology used can indirectly enhance the flame retardant ability of the material while maintaining the thermal stability of the material structure. In addition, the flame retardant properties of the material are further optimized by applying grafting technology. Single factor experiments show that after using grafting technology, the limiting oxygen index of the material is increased by an additional 2%. This shows that the grafting technology can work synergistically with the intercalation technology and the composite blending modification technology to significantly improve the flame retardant properties of polyhexamethylene adipamide flame retardant materials.
[0022] The present application achieves the goal of maintaining the flame retardant properties and mechanical properties of the material while combining with the grafting technology, effectively reducing the water contact angle of the material, thereby improving the easy cleanability of the material by precisely controlling the amount of flame retardant modifier added to the polyhexamethylene adipamide flame retardant material, thereby improving the easy cleanability of the material. The applicant's research found that the amount of flame retardant modifier added directly affects the water contact angle of the material. When only the polyhexamethylene adipamide material after grafting was tested, it was found that the water contact angle was significantly reduced. However, if the grafting technology is applied to the polyhexamethylene adipamide flame retardant material that has been treated with phosphorus-based flame retardant intercalation and composite blending modification, the water contact angle will significantly rise. Through in-depth research, the applicant found that this problem can be effectively solved by adjusting the amount of flame retardant modifier added. After such optimization treatment, the water contact angle of the material not only did not rise, but was further reduced. This means that the grafting technology can not only work in conjunction with the phosphorus-based flame retardant intercalation technology and the composite blending modification technology to jointly improve the flame retardant properties of the polyhexamethylene adipamide flame retardant material, but also enhance the surface properties and easy cleanability 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 1 This is a flow chart of the preparation of the flame retardant material of polyhexamethylene adipamide in Example 1 of the present application;
[0025] Figure 2 This is a flow chart for preparing the polyhexamethylene adipamide flame retardant material according to 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 polyhexamethylene adipamide flame retardant material, which specifically comprises the following steps:
[0029] S1. In 5000 parts of distilled water, add 100 parts of CuSO4, 20 parts of Al2(SO4)3, 10 parts of sodium dodecylbenzene sulfonate, and 30 parts of 2-carboxyethylphenylphosphinic acid. The mixture is stirred continuously for 10 hours at 60°C and pH=7 (with urea added). After the reaction, the product is filtered to obtain the product, and washed with a large amount of distilled water. Finally, the self-assembly flame retardant modifier SDBS-O is obtained after vacuum drying for 12 hours. p FR-LDH.
[0030] S2, at 40 ~ 100 ℃, respectively, polyhexamethylene adipamide, flame retardant modifier SDBS-O p FR-LDH, the 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)) and glass fiber, vacuum drying for 1 to 10 hours. Then, 70wt% polyhexamethylene adipamide, 7wt% flame retardant modifier SDBS-OpFR-LDH, 2wt% first antioxidant, 2wt% toughening agent, 4wt% compatibilizer and 15wt% glass fiber are put into a high-speed mixer and mixed for 2 to 10 minutes, and 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℃, the three sections of the screw center temperature are 240℃, 265℃, 250℃, and the die temperature is 190℃, and finally the polyhexamethylene adipamide flame retardant material is obtained.
[0031] S3. The prepared polyhexamethylene adipamide flame retardant material, methanol and water are placed in a reaction vessel at a mass feed ratio of 1:7:15. Based on 100 parts by mass of the polyhexamethylene adipamide flame retardant material, sulfobetaine methacrylate (SBMA), initiator (benzoyl peroxide) and second antioxidant (diphenylamine) are added in a mass feed ratio of 8:2:0.7 respectively. Stirring is started and the temperature is slowly raised to 60°C under nitrogen to perform free radical polymerization. After reacting for 3 hours, the mixture is washed and dried with an ethanol solution, i.e., the betaine-type zwitterionic polymer is grafted onto the surface of the polyhexamethylene adipamide flame retardant material, which significantly improves the easy-to-clean property of the material.
[0032] Example 2
[0033] This embodiment discloses a method for preparing a polyhexamethylene adipamide flame retardant material, which specifically comprises the following steps:
[0034] S1. In terms of mass fractions, 100 parts of CuSO4, 20 parts of Al2(SO4)3, 10 parts of sodium dodecylbenzene sulfonate, and 30 parts of 2-carboxyethylphenylphosphinic acid were added to 5000 parts of distilled water. The hydrothermal reaction was carried out under continuous stirring at 60°C and pH=7 (with urea added) for 10 hours. After the reaction was completed, the product was filtered to obtain the product, and washed with a large amount of distilled water. Finally, the self-assembly flame retardant modifier SDBS-O was obtained after vacuum drying for 12 hours. p FR-LDH.
[0035] S2, at 40 ~ 100 ℃, respectively, polyhexamethylene adipamide, flame retardant modifier SDBS-O p FR-LDH, the 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)) and glass fiber, vacuum drying for 1 to 10 hours. Then, 70wt% polyhexamethylene adipamide, 7wt% flame retardant modifier SDBS-OpFR-LDH, 2wt% first antioxidant, 2wt% toughening agent, 4wt% compatibilizer and 15wt% glass fiber are put into a high-speed mixer and mixed for 2 to 10 minutes, and 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℃, the three sections of the screw center temperature are 240℃, 265℃, 250℃, and the die temperature is 190℃, and finally the polyhexamethylene adipamide flame retardant material is obtained.
[0036] Example 3
[0037] This embodiment discloses a method for preparing a polyhexamethylene adipamide flame retardant material, which specifically comprises the following steps:
[0038] S1. In terms of mass fractions, 100 parts of CuSO4, 70 parts of Al2(SO4)3, 30 parts of sodium dodecyl sulfate, and 40 parts of 2-carboxyethylphenylphosphinic acid were added to 5000 parts of distilled water. The hydrothermal reaction was carried out under continuous stirring at 60°C and pH=10 (with urea added) for 10 hours. After the reaction was completed, the product was filtered to obtain the product, and washed with a large amount of distilled water. Finally, the self-assembly flame retardant modifier SDS-O was obtained after vacuum drying for 12 hours. p FR-LDH.
[0039] S2, at 40 ~ 100 ℃, respectively, polyhexamethylene adipamide and flame retardant modifier SDS-O pFR-LDH, the 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)) and glass fiber, vacuum drying for 1 to 10 hours. Then, 95wt% polyhexamethylene adipamide, 1wt% flame retardant modifier SDS-OpFR-LDH, 0.3wt% first antioxidant, 0.5wt% toughening agent, 1.2wt% compatibilizer and 2wt% glass fiber are put into a high-speed mixer and mixed for 2 to 10 minutes, and 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℃, the three sections of the screw center temperature are 240℃, 265℃, 250℃, and the die head temperature is 190℃, and finally the polyhexamethylene adipamide flame retardant material is obtained.
[0040] S3. The prepared polyhexamethylene adipamide flame retardant material, methanol and water are placed in a reaction vessel at a mass feed ratio of 1:7:15. Based on 100 parts by mass of the polyhexamethylene adipamide flame retardant material, sulfobetaine methacrylate (SBMA), initiator (benzoyl peroxide) and second antioxidant (diphenylamine) are added in a mass feed ratio of 5:2:0.7, respectively. Stirring is started, and the temperature is slowly raised to 30°C under nitrogen to perform free radical polymerization. After 6 hours of reaction, the reaction is washed and dried with an ethanol solution, that is, the betaine-type zwitterionic polymer is grafted onto the surface of the polyhexamethylene adipamide flame retardant material, which significantly improves the easy-to-clean property of the material.
[0041] Example 4
[0042] This embodiment discloses a method for preparing a polyhexamethylene adipamide flame retardant material, which specifically comprises the following steps:
[0043] S1. In 5000 parts of distilled water, add 100 parts of CuSO4, 70 parts of Al2(SO4)3, 15 parts of sodium dodecylbenzene sulfonate, and 20 parts of 2-carboxyethylphenylphosphinic acid. The reaction was carried out under continuous stirring at 110°C and pH=8 (with urea added) for 24 hours. After the reaction was completed, the product was filtered and washed with a large amount of distilled water. Finally, the self-assembly flame retardant modifier SDBS-O was obtained after vacuum drying for 12 hours. p FR-LDH.
[0044] S2, at 40 ~ 100 ℃, respectively, polyhexamethylene adipamide and flame retardant modifier SDS-O pFR-LDH, the 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)) and glass fiber, vacuum drying for 1 to 10 hours. Then, 70wt% polyhexamethylene adipamide, 5wt% flame retardant modifier SDBS-OpFR-LDH, 4wt% first antioxidant, 4wt% toughening agent, 5wt% compatibilizer and 12wt% glass fiber are put into a high-speed mixer and mixed for 2 to 10 minutes, and 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℃, the temperatures of the three sections in the center of the screw are 240℃, 265℃, 250℃, respectively, and the die temperature is 190℃, and finally the polyhexamethylene adipamide flame retardant material is obtained.
[0045] S3. The prepared polyhexamethylene adipamide flame retardant material, methanol and water are placed in a reaction vessel at a mass feed ratio of 1:7:15. Based on 100 parts by mass of the polyhexamethylene adipamide flame retardant material, sulfobetaine methacrylate (SBMA), initiator (benzoyl peroxide) and second antioxidant (diphenylamine) are added in a mass feed ratio of 15:2:0.7, respectively. Stirring is started, and the temperature is slowly raised to 50°C under nitrogen to perform free radical polymerization. After reacting for 5 hours, the reaction is washed and dried with an ethanol solution, that is, the betaine-type zwitterionic polymer is grafted onto the surface of the polyhexamethylene adipamide flame retardant material, which significantly improves the easy-to-clean property of the material.
[0046] Example 5
[0047] This embodiment discloses a method for preparing a polyhexamethylene adipamide flame retardant material, which specifically comprises the following steps:
[0048] S1. In terms of mass fractions, add 100 parts of CuSO4, 20 parts of Al2(SO4)3, 10 parts of sodium dodecyl sulfate, 30 parts of 2-carboxyethylphenylphosphinic acid, and 50 parts of urea to 5000 parts of distilled water. Continue stirring at 60°C and pH=7 to carry out hydrothermal reaction for 10 hours. After the reaction is completed, filter the product, wash it with a large amount of distilled water, and finally vacuum dry it for 12 hours to obtain the self-assembling flame retardant modifier SDS-O. p FR-LDH.
[0049] S2, at 40 ~ 100 ℃, respectively, polyhexamethylene adipamide and flame retardant modifier SDS-O pFR-LDH, the 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)) and glass fiber, vacuum drying for 1 to 10 hours. Then, 70.5wt% polyhexamethylene adipamide, 5wt% flame retardant modifier SDS-OpFR-LDH, 3wt% first antioxidant, 1wt% toughening agent, 0.5wt% compatibilizer and 20wt% glass fiber are put into a high-speed mixer and mixed for 2 to 10 minutes, and 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℃, the temperatures of the three sections in the center of the screw are 240℃, 265℃, 250℃, and the die temperature is 190℃, and finally the polyhexamethylene adipamide flame retardant material is obtained.
[0050] S3. The prepared polyhexamethylene adipamide flame retardant material, methanol and water are placed in a reaction vessel at a mass feed ratio of 1:7:15. Based on 100 parts by mass of the polyhexamethylene adipamide flame retardant material, sulfobetaine methacrylate (SBMA), initiator (benzoyl peroxide) and second antioxidant (diphenylamine) are added in a mass feed ratio of 8:2:0.7 respectively. Stirring is started and the temperature is slowly raised to 60°C under nitrogen to perform free radical polymerization. After reacting for 3 hours, the mixture is washed and dried with an ethanol solution, i.e., the betaine-type zwitterionic polymer is grafted onto the surface of the polyhexamethylene adipamide flame retardant material, which significantly improves the easy-to-clean property of the material.
[0051] Comparative Example 1
[0052] The difference between the preparation process of the polyhexamethylene adipamide flame retardant material in this comparative example and that in Example 1 is as follows: Step S1: flame retardant modifier SDBS-0 p During the preparation of FR-LDH, 2-carboxyethylphenylphosphinic acid was not added, and therefore, 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 polyhexamethylene adipamide flame retardant material of this comparative example and that of 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. p FR-LDH.
[0055] Comparative Example 3
[0056] The difference between the preparation process of the polyhexamethylene adipamide flame retardant material in this comparative example and that in Example 1 is as follows: Step S1: flame retardant modifier SDBS-0 p During the preparation of FR-LDH, 50 parts of 2-carboxyethylphenylphosphinic acid were added.
[0057] Comparative Example 4
[0058] The difference between the preparation process of the polyhexamethylene adipamide flame retardant material of this comparative example and that of Example 1 is that it only includes step S3, and the polyhexamethylene adipamide flame retardant material is polyhexamethylene adipamide.
[0059] Comparative Example 5
[0060] The difference between the preparation process of the polyhexamethylene adipamide flame retardant material of this comparative example and that of Example 1 is that in step S2, the addition amount of the flame retardant modifier SDBS-OpFR-LDH is 10 wt %, and correspondingly, the addition amount of the polyhexamethylene adipamide is 67 wt %.
[0061] Performance Testing
[0062] This performance test tests the limiting oxygen index, vertical combustion performance, hydrophilicity and tensile strength of the polyhexamethylene adipamide 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 / T1040. The integrated table is as follows:
[0063] Table 1. Performance parameters
[0064]
[0065] The experimental results of the blank groups of Example 1 and Comparative Example 2 show that the present application prepares the flame retardant modifier SDBS-OpFR-LDH by intercalating the phosphorus flame retardant between the layered double metal hydroxide layers, and uses polyhexamethylene adipamide (PA66) as the substrate, introduces the flame retardant modifier SDBS-OpFR-LDH through the composite blending modification technology, and finally grafts the betaine type zwitterionic polymer to the surface of the polyhexamethylene adipamide flame retardant material through the atom transfer radical polymerization (ATRP) technology, which greatly improves the flame retardant performance and easy cleaning of the polyhexamethylene adipamide flame retardant material. Specifically, the limiting oxygen index of the present application is increased by 12% compared with the blank group, and the vertical combustion level is increased from V2 to V0, which shows that the flame retardant effect is good. Secondly, although the present application adds phosphorus flame retardant materials, the overall mechanical properties of the material are still guaranteed, and its tensile strength is only reduced by 8Mpa. In addition, the water contact angle of the material is reduced from 65° to 25°, indicating that the polyhexamethylene adipamide flame retardant material is also easy to clean compared to polyhexamethylene adipamide. In addition, by comparing Example 2 and Comparative Example 2, it can be found that when the polyhexamethylene adipamide flame retardant material is not grafted, the flame retardant performance of the polyhexamethylene adipamide flame retardant material is still relatively excellent, and only the limiting oxygen index is reduced by 2% compared to Example 1. On the contrary, it can be seen that on the one hand, the phosphorus-based flame retardant intercalation technology and the composite blending modification technology of the present application can cooperate with each other to improve the flame retardant performance of the polyhexamethylene adipamide flame retardant material; further, by further introducing free radical polymerization reaction, the grafting technology can cooperate with the phosphorus-based flame retardant intercalation technology and the composite blending modification technology to further improve the flame retardant performance of the material.
[0066] From the perspective of surface cleanability, Comparative Example 4 shows that grafting betaine-type zwitterionic polymers to the surface of polyhexamethylene adipamide flame retardant materials effectively reduces the water contact angle of polyhexamethylene adipamide flame retardant materials and significantly improves the easy cleanability of the materials. However, the polyhexamethylene adipamide flame retardant material of the present application is different from the polyhexamethylene adipamide of Comparative Example 4, and is prepared by phosphorus-based flame retardant intercalation technology and composite blending modification process. Therefore, in Comparative Example 5, only 3wt% of the addition amount of the flame retardant modifier SDBS-OpFR-LDH is increased, and the water contact angle is increased by 5° compared with Example 1. It can be seen that the present application can cooperate with the grafting technology, intercalation technology and composite blending modification technology by adjusting the addition amount of the flame retardant modifier SDBS-OpFR-LDH to jointly reduce the water contact angle of the polyhexamethylene adipamide flame retardant material and increase the easy cleanability of the material.
[0067] In addition, the experimental results of Example 1 and Comparative Example 3 show that when a large amount of phosphorus flame retardant is added, it will have a greater impact on the mechanical properties of the polyhexamethylene adipamide flame retardant material. Specifically, compared with Example 1, Comparative Example 3 adds 20 more parts of phosphorus flame retardant, and its limiting oxygen index, vertical combustion level and water contact angle are basically unchanged, and the tensile strength is reduced by 22Mpa compared with Example 1. It can be seen that the present application can cooperate with other raw materials to achieve reasonable control of tensile strength under the premise of ensuring flame retardancy through the design of the addition amount of phosphorus flame retardant, and the material has good mechanical properties, which can indirectly increase the flame retardant properties of the material and has better application prospects.
Claims
1. A method for preparing a polyhexamethylene adipamide flame retardant material, characterized in that: The following steps are involved: S1, intercalating a phosphorus flame retardant between layers of a layered double metal hydroxide to obtain a flame retardant modifier; S2. Calculated by mass percentage, 70-95wt% of polyhexamethylene adipamide, 1-7wt% of flame retardant modifier, 0.3-4wt% of first antioxidant, 0.5-4wt% of toughening agent, 0.5-5wt% of compatibilizer and 2-20wt% of reinforcing agent are mixed, extruded and granulated to obtain polyhexamethylene adipamide flame retardant material.
2. The method for preparing a polyhexamethylene adipamide flame retardant material according to claim 1, characterized in that: Also includes: S3, subjecting the polyhexamethylene adipamide flame retardant material to a free radical polymerization reaction with a free radical polymerization initiator, a second antioxidant and a betaine type zwitterionic monomer mixture to obtain a surface treated polyhexamethylene adipamide flame retardant material.
3. The method for preparing a polyhexamethylene adipamide 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 phosphorus-based flame retardant to a hydrothermal reaction in an alkaline environment.
4. The method for preparing a polyhexamethylene adipamide 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 phosphorus flame retardant.
5. The method for preparing a polyhexamethylene adipamide 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 phosphorus flame retardant.
6. The method for preparing a polyhexamethylene adipamide flame retardant material according to claim 1, characterized in that: Before the mixed extrusion granulation in step S2, the polyhexamethylene adipamide, the flame retardant modifier, the first antioxidant, the toughening agent, the compatibilizer and the reinforcing agent are respectively subjected to vacuum drying treatment.
7. The method for preparing a polyhexamethylene adipamide flame retardant material according to claim 2, characterized in that: In step S3, calculated by weight, the polyhexamethylene adipamide flame retardant material is 100 parts, the free radical polymerization initiator is 2 parts, the second antioxidant is 0.7 parts, and the betaine type zwitterionic monomer is 5 to 15 parts.
8. The method for preparing a polyhexamethylene adipamide flame retardant material according to claim 2 or 7, characterized in that: The reaction conditions of free radical polymerization are: temperature 30-60°C and reaction time 3-6h.
9. The flame retardant polyhexamethylene adipamide material prepared by the preparation method according to any one of claims 1 to 8.
10. Use of the polyhexamethylene adipamide flame retardant material according to claim 9 in kitchen equipment.