Interface assembly modified halloysite nanotubes, composites thereof and methods of making
By modifying halloysite nanotubes through interfacial assembly, the problems of insufficient dispersion and interfacial bonding of halloysite in polymers were solved, improving the mechanical properties and electromagnetic shielding performance of the composite material and expanding its application range.
Patent Information
- Application Number
- CN202310734482.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-20
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2043-06-20
AI Technical Summary
Existing special engineering plastics suffer from reduced rigidity and poor toughening effect during the toughening process. Halloysite nanotubes have insufficient dispersion and interfacial bonding in polymers, resulting in insufficient mechanical properties and impact resistance of composite materials.
Halloysite nanotubes were modified using interfacial assembly technology and ionic reaction. By loading modifying materials on the inner and outer surfaces of the halloysite nanotubes, their compatibility with the polymer matrix and interfacial bonding ability were improved. Interfacially assembled modified halloysite nanotubes were then prepared and melt-blended with polymers.
It significantly improves the mechanical properties, electromagnetic shielding properties, and smoke suppression properties of composite materials, enhances the impact resistance and flame retardant properties of polymers, improves the dispersibility and interfacial bonding of halloysite in polymers, and reduces production energy consumption and costs.
Smart Images
Figure CN116903932B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to an interface assembly modified halloysite nanotube and a composite material thereof, and a preparation method thereof, and belongs to the technical field of mechanical reinforcement of polymer materials, smoke suppression materials and electromagnetic shielding. BACKGROUND
[0002] Although the special engineering plastics used in the fields of electronic appliances, aerospace, automobile transportation, machinery and chemical industry can achieve excellent high-temperature resistance, corrosion resistance, radiation resistance and flame retardance, the common special engineering plastics still generally have the problems of poor toughness and weak impact resistance, which greatly limits the application of the special engineering plastics. The traditional engineering plastics are usually toughened by rubber or thermoplastic elastomer, although the toughening effect is good, but the rigidity of the engineering plastics is greatly reduced. The current solution is usually to cooperate with certain inorganic rigid particles as reinforcing agents to avoid the large decrease in rigidity, but this will affect the toughening effect.
[0003] Halloysite has a multi-walled nanotube structure, is a naturally occurring nanoscale tubular mineral material, and has the advantages of easy availability, wide source, low price, low processing difficulty, non-toxicity and good biocompatibility compared with synthetic nanotubes. Its unique structure enables it to impart diversified properties to the composite material through modification. Meanwhile, halloysite is also a commonly used inorganic filler, but when it is applied in organic polymers, it often has the problems of poor dispersion and insufficient bonding force between the polymer matrix, thereby greatly reducing the reinforcing effect of halloysite on the polymer.
[0004] Firstly, the nanomaterials represented by halloysite are prone to agglomeration after being introduced into polymers, resulting in the loss of small size advantage. When the composite material is stressed, the position of these agglomerates usually first breaks due to stress concentration, resulting in insignificant reinforcing effect of the filler, and even the strength of the composite material is not improved after modification when the agglomeration is serious.
[0005] Secondly, the nanomaterials represented by halloysite have weak interfacial interaction with polymers. The existence of the interface can prevent the propagation of cracks and slow down stress concentration, so that the filler and the matrix form a whole and transfer stress. If the wettability between the matrix and the filler is not good, the interfacial adhesion strength is low, which will directly affect the performance of the composite material.
[0006] Therefore, how to modify halloysite to better apply it to composite materials, reduce agglomeration and effectively improve the mechanical properties of the composite material is one of the technical problems to be solved by the person skilled in the art. SUMMARY
[0007] The purpose of the present application is to modify the halloysite by using the interface assembly technology and ion reaction, and then to improve the compatibility and interface binding capacity of the halloysite and the polymer matrix, reduce the agglomeration, and improve the static mechanics, low-speed dynamic impact resistance, smoke suppression performance in fire scenarios and the like of the composite material.
[0008] The present application provides an interface assembly modified halloysite nanotube, comprising: a hollow halloysite nanotube, a layer of modified material loaded on the outer surface of the halloysite nanotube, and a layer of modified material also loaded on the inner cavity surface of the halloysite nanotube, wherein the modified material is generated by the reaction of a carbon-containing organic acid aqueous solution with an amino compound and a metal ion aqueous solution.
[0009] According to a specific but non-limiting embodiment of the present application, wherein the carbon-containing organic acid is at least one of phytic acid, tannic acid, oxalic acid, azelaic acid, fumaric acid, citric acid, vanillic acid, coffee acid and itaconic acid; the amino compound is at least one of melamine, nicotinamide, piperazine, diphenylamine, p-toluidine, triphenylamine and tertiary octylamine; and the metal ion aqueous solution is at least one of FeCl3·6H2O, CoCl2·6H2O, NiSO4·6H2O and CuCl2·2H2O aqueous solution.
[0010] The present application also provides a preparation method of the interface assembly modified halloysite nanotube, comprising:
[0011] A certain amount of amino compound is uniformly mixed with the metal ion aqueous solution to form a compound mixed solution a for standby;
[0012] The halloysite nanotube is mixed with a certain amount of carbon-containing organic acid aqueous solution, and stirred uniformly at room temperature of 15-30℃ to form a compound mixed solution b for standby;
[0013] The compound mixed solution a is slowly added to the compound mixed solution b, and stirred for 5-20 minutes at room temperature of 15-30℃;
[0014] After the product is centrifuged, washed, dried and ground, the interface assembly modified halloysite nanotube is obtained.
[0015] According to a specific but non-limiting embodiment of the present application, wherein the amino compound is at least one of melamine, nicotinamide, piperazine, diphenylamine, p-toluidine, triphenylamine and tertiary octylamine; the metal ion aqueous solution is at least one of FeCl3·6H2O, CoCl2·6H2O, NiSO4·6H2O and CuCl2·2H2O aqueous solution; and the carbon-containing organic acid is at least one of phytic acid, tannic acid, oxalic acid, azelaic acid, fumaric acid, citric acid, vanillic acid, coffee acid and itaconic acid.
[0016] According to a specific but non-limiting embodiment of the present application, the amino compound, the metal ion compound and the pure water are prepared into a complex mixed solution a according to a mass ratio of (1-2):1:(20-25).
[0017] According to a specific but non-limiting embodiment of the present application, the halloysite, the carbon-containing organic acid and the pure water are prepared into a complex mixed solution b according to a mass ratio of 1:(1-2):(6-7).
[0018] According to a specific but non-limiting embodiment of the present application, the mass ratio of the complex mixed solution a and the complex mixed solution b is (1-2):1.
[0019] In another aspect, the present application also provides an interfacial assembly modified halloysite-based nanocomposite, which comprises the interfacial assembly modified halloysite nanotube and the polymer as described above, and the polymer is an impact-resistant engineering plastic, rubber or polyurethane.
[0020] According to a specific but non-limiting embodiment of the present application, the interfacial assembly modified halloysite nanotube accounts for 2wt%-15wt% of the total weight of the composite material; the impact-resistant engineering plastic is polyethylene, polylactic acid, polypropylene or polyvinyl chloride; and the rubber is ethylene-propylene-diene rubber or nitrile rubber.
[0021] The present application also provides a preparation method of the interfacial assembly modified halloysite-based nanocomposite, which comprises: melt blending the interfacial assembly modified halloysite nanotube and the polymer in an internal mixer to obtain.
[0022] The present application has the following beneficial effects:
[0023] 1. The present application uses green and environmentally friendly halloysite as a raw material, and modifies the inner cavity and outer surface space of the halloysite nanotube based on efficient ion reaction and self-assembly technology. The modified halloysite nanotube is uniformly dispersed in the polymer matrix, greatly reduces the agglomeration, effectively improves the compatibility and interfacial bonding capacity of the halloysite and the polymer matrix, and greatly improves the mechanical properties of the composite material.
[0024] 2. In the process of modifying the halloysite, no toxic, harmful and volatile organic solvents are used, the preparation process is low in energy consumption, and the preparation time is very short, which can be completed in no more than 1 hour at room temperature, and has the advantages of high efficiency, convenience, low energy consumption, high yield and the like in the preparation process.
[0025] 3. The composite material prepared by adding the interface assembled modified halloysite nanotube into the polymer matrix, not only the mechanical properties (breaking strength and elongation at break) and impact strength are significantly improved, but also the electromagnetic shielding performance and smoke suppression performance are good, the release of smoke poison during combustion can be effectively suppressed, and the composite material can be applied to the fields of enhancing polymer impact resistance, flame retardation, electromagnetic shielding and the like. BRIEF DESCRIPTION OF DRAWINGS
[0026] Figure 1a It is a structural schematic diagram of the interface assembled modified halloysite nanotube.
[0027] Figure 1b It is a cross-sectional chemical structure schematic diagram of the interface assembled modified halloysite nanotube.
[0028] Figure 2a It is a transmission electron microscope (TEM) image of the halloysite.
[0029] Figure 2b It is a TEM image of the interface assembled modified halloysite nanotube in one specific embodiment of the present application.
[0030] Figure 3a It is a scanning electron microscope (SEM) image of a brittle fracture section of the halloysite-based nanocomposite material.
[0031] Figure 3b It is a SEM image of a brittle fracture section of the interface assembled modified halloysite-based nanocomposite material in one specific embodiment of the present application. DETAILED DESCRIPTION
[0032] The following specific embodiments are provided to further illustrate the present application, but the present application is not limited to the following embodiments.
[0033] The interface assembly technology is to combine different materials together by using chemical (positive and negative charge ion interaction, π-π and π=π) and physical interaction (van der Waals force and hydrogen bond interaction) between materials, form a new structure, and thus obtain better overall performance. The interface assembly technology has the advantages of simple and easy method, strong controllability, strong material stability and the like.
[0034] The present application simultaneously performs assembly modification on the inner and outer surfaces of halloysite by using the interface assembly technology and ion reaction, fully utilizes the inner cavity space of halloysite, and thus improves the compatibility and interface bonding capacity of halloysite and the polymer matrix, and further improves the mechanical properties, electromagnetic shielding performance and smoke suppression performance of the high polymer composite material. The modification of the inner cavity of halloysite is still the first time in the present application, and no literature report is found at present.
[0035] Figure 1a and Figure 1brespectively are structural schematic diagram and section chemical structure schematic diagram of interface assembly modified halloysite nanotube provided by the present application. Figure 1a and Figure 1b As shown in the present application, the interface assembly modified halloysite nanotube comprises: hollow halloysite nanotube 1, a layer of modified material 2 is loaded on the outer surface of the halloysite nanotube 1, and a layer of modified material 2 is also loaded on the inner cavity surface of the halloysite nanotube 1, wherein the modified material 2 is generated by reacting carbon-containing organic acid aqueous solution with amino compound and metal ion aqueous solution. Specifically, the modified material is a self-bottom-to-top formed lamellar structure carbon-containing organic acid-amino salt.
[0036] Since the halloysite has a nanotube hollow structure and the inner and outer surfaces have heterogeneous charges, the outer surface has negative charge and the inner cavity wall has positive charge, we can make the modifier grow on the inner and outer surfaces of the halloysite nanotube based on the interface assembly technology, and load a layer of modified material on the inner and outer surfaces, respectively. The specific modification process and reaction principle are as follows:
[0037] (1) The carbon-containing organic acid aqueous solution providing negative charge is used as the interface assembly precursor to load on the halloysite inner cavity wall.
[0038] (2) Halloysite outer surface assembly: first, a part of the positive charged amino compound and metal ion aqueous solution grows in situ on the outer surface of the halloysite; then, the free carbon-containing organic acid in the reaction solution assembles on the outer surface of the halloysite.
[0039] (3) Halloysite inner surface assembly: another part of the positive charged amino compound and metal ion aqueous solution reacts with the halloysite loaded with carbon-containing organic acid on the inner cavity wall in (1).
[0040] Based on the supramolecular self-assembly technology, the present application uses amino compound, carbon-containing organic acid and metal ion compound as raw materials, fully utilizes the non-covalent bond interaction between molecules such as hydrogen bond interaction, π-π interaction and electrostatic interaction, and forms the modified material with lamellar structure from bottom to top. The modified material is combined with the halloysite, and the modified material can be assembled on the surface of the halloysite nanotube as a mother plate to realize specific functions. Figure 2b is a transmission electron microscope image of the interface assembly modified halloysite nanotube prepared in one specific embodiment of the present application, from Figure 2b It can be seen that the prepared interface assembly modified halloysite nanotube still retains the original one-dimensional nanotube structure, and the chemical structure is as shown in Figure 1b .
[0041] Specifically, the present application provides a preparation method of the interface assembly modified halloysite nanotube, comprising:
[0042] (1) A certain amount of amino compound is mixed with metal ion aqueous solution uniformly to form a complex mixed solution a for standby use;
[0043] (2) mixing the halloysite nanotubes with a certain amount of aqueous solution of carbon-containing organic acid, stirring uniformly at room temperature of 15-30℃ to form a compound mixed solution b for standby;
[0044] (3) slowly adding the compound mixed solution a into the compound mixed solution b, stirring at room temperature of 15-30℃ for 5-20 minutes;
[0045] (4) after centrifugal washing, drying and grinding, the product is obtained.
[0046] Preferably, the amino compound is an organic compound with one or more than one amino group, such as melamine, nicotinamide, piperazine, diphenylamine, p-toluidine, triphenylamine and / or tertiary octylamine, etc.
[0047] The aqueous solution of metal ions is an aqueous solution of FeCl3·6H2O, CoCl2·6H2O, NiSO4·6H2O and / or CuCl2·2H2O, etc.
[0048] Generally, the amino compound, the metal ion compound and pure water are prepared into the compound mixed solution a according to the mass ratio of (1-2):1:(20-25).
[0049] The carbon-containing organic acid is an organic acid compound containing carbon elements, such as phytic acid, tannic acid, oxalic acid, azelaic acid, fumaric acid, citric acid, vanillic acid, coffee acid and / or itaconic acid, etc.
[0050] Generally, the halloysite, the carbon-containing organic acid and pure water are prepared into the compound mixed solution b according to the mass ratio of 1:(1-2):(6-7).
[0051] Generally, the mass ratio of the compound mixed solution a to the compound mixed solution b is (1-2):1.
[0052] In the above step 3, the stirring speed when the compound mixed solution a is added into the compound mixed solution b is generally 300-1000 r / min; the centrifugal washing and drying conditions are that the solid product is washed with pure water for 3-5 times under the centrifugal speed of 2000-3000 r / min for 1-2 min, and then dried at 100-120℃ until constant weight.
[0053] Further, the application also provides an interface-assembled modified halloysite-based nanocomposite material, which comprises the interface-assembled modified halloysite nanotubes and a polymer, wherein the interface-assembled modified halloysite nanotubes account for 2wt%-15wt% of the total weight of the composite material. The composite material is obtained by melt blending the interface-assembled modified halloysite nanotubes and the polymer in an internal mixer.
[0054] Preferably, the polymer is an impact-resistant engineering plastic, rubber or polyurethane, etc. The impact-resistant engineering plastic is polyethylene, polylactic acid, polypropylene or polyvinyl chloride, etc. The rubber is ethylene-propylene rubber or nitrile rubber, etc.
[0055] Figure 3b is a scanning electron microscope image of a brittle fracture section of the interfacial assembly modified halloysite-based nanocomposite prepared in a specific embodiment of the present application. Figure 3b It can be seen that the interfacial assembly modified halloysite nanomaterial of the present application is in a hollow nanotube state under a microscope and can be uniformly dispersed in a polymer matrix, thus effectively improving the static mechanics, low-speed dynamic impact resistance and smoke suppression performance in a fire scenario of the polymer material.
[0056] The modifier used in the present application is an organic compound, which has a similar polarity to the high-molecular polymer matrix, thus improving the compatibility and dispersibility of the halloysite nanotube interface. The halloysite nanotube with excellent interface compatibility and dispersibility can effectively disperse impact / tension energy, thus improving the mechanical properties (both the breaking strength and the breaking elongation are significantly improved) and impact resistance of the composite material. The interfacial assembly modified halloysite of the present application has a special one-dimensional structure and metal conductive elements, and the polymer added with it thus has certain electromagnetic shielding performance. The modifier used is high in nitrogen element content and the one-dimensional nanomaterial has the characteristics of inhibiting heat transfer and material exchange, thus endowing the composite material with excellent flame retardation and smoke suppression performance, and the present application can be widely applied in the fields of aerospace, electronics and electrical appliances, etc.
[0057] The halloysite modification method of the present application is low in energy consumption, environmentally friendly, efficient, short in preparation time, high in yield, low in production cost, simple in operation, free of toxic and harmful reagents and volatile organic solvents, and can be used for industrial mass production and is easy to operate. The present application improves the dispersibility of the modified halloysite in the polymer matrix, thus the modified halloysite only needs a lower addition amount to obtain excellent mechanical properties of the composite material, such as the toughness, mechanical strength, breaking elongation and impact resistance of the composite material are all significantly improved, thus greatly improving the added value of the engineering plastic product, expanding the application range thereof, and having a wide market prospect and significant social benefits.
[0058] The present application will be further described below in combination with specific embodiments, but the present application is not limited to the following embodiments. The experimental methods used in the above and the following embodiments are all conventional methods unless otherwise specified. The materials, reagents, etc. used in the above and the following embodiments can be obtained from commercial channels unless otherwise specified.
[0059] To make the present application easier to understand, the present application will be further described below taking polylactic acid engineering plastic as an example.
[0060] Comparative Example 1
[0061] Preparation of control sample pure polylactic acid resin material
[0062] 100 g of commercially available polylactic acid masterbatch was prepared into a pure polylactic acid resin material by means of melt blending in an internal mixer, and a flat vulcanizing machine was used to press it into a test standard sample, which was denoted as PLA-1.
[0063] Comparative Example 2
[0064] Preparation of control sample composite material
[0065] 2 g of commercially available halloysite was mixed with 98 g of polylactic acid masterbatch by means of direct melt blending in an internal mixer to prepare a polylactic acid composite material, and a flat vulcanizing machine was used to press it into a test standard sample, which was denoted as PLA-2. Figure 3a is a scanning electron microscope image of the brittle fracture surface of the halloysite-based nanocomposite material.
[0066] Example 1
[0067] Preparation of interface-assembled modified halloysite powder 1 and its polymer composite test sample PLA-3
[0068] a. 20 g of nicotinamide and 13.5 g of FeCl3·6H2O were dissolved in 300 g of pure water, stirred uniformly with a glass rod, and fully dissolved to form a mixed solution a;
[0069] b. 30 g of halloysite and 47 g of phytic acid were dissolved in 200 g of pure water, and stirred vigorously at room temperature 25℃ for 5 min to form a mixed solution b;
[0070] c. The mixed solution a was added dropwise to the mixed solution b, and mechanically stirred at room temperature 25℃ for 5 min to obtain a solution containing the target product;
[0071] d. After centrifugation and pure water washing 4 times, the product was dried at 100℃ for 24 h to obtain the interface-assembled modified halloysite powder 1; Figure 2b is a transmission electron microscope image of the interface-assembled modified halloysite;
[0072] e. 2 g of interface-assembled modified halloysite powder 1 was mixed with 98 g of polylactic acid masterbatch by means of direct melt blending in an internal mixer to prepare a polylactic acid composite material, and a flat vulcanizing machine was used to press it into a test standard sample, which was denoted as PLA-3. Figure 3b is a scanning electron microscope image of the brittle fracture surface of the interface-assembled modified halloysite-based nanocomposite material.
[0073] Example 2
[0074] Preparation of interface-assembled modified halloysite powder 2 and its polymer composite test sample PLA-4
[0075] a. 20 g of piperazine and 13.5 g of CoCl2·6H2O were dissolved in 300 g of pure water, stirred uniformly with a glass rod, and fully dissolved to form a mixed solution a;
[0076] b. 30 g of halloysite and 47 g of phytic acid were dissolved in 200 g of pure water, and stirred vigorously at room temperature of 25°C for 5 min to form a mixed solution b;
[0077] c. The mixed solution a was added dropwise to the mixed solution b, and mechanically stirred at room temperature of 25°C for 10 min to obtain a solution containing the target product;
[0078] d. The product was centrifuged and washed with pure water for 4 times, dried at 100°C for 24 h, and ground to obtain the interface-assembled modified halloysite powder 2;
[0079] e. 2 g of the interface-assembled modified halloysite powder 2 was mixed with 98 g of polylactic acid master batch by a direct melt blending method through an internal mixer to prepare a polylactic acid composite material, and a flat vulcanizing machine was used to press it into a test standard sample, which was recorded as PLA-4.
[0080] Example 3
[0081] Preparation of interface-assembled modified halloysite powder 3 and its polymer composite test sample PLA-5
[0082] a. 20 g of diphenylamine and 14.6 g of CoCl2·6H2O were dissolved in 300 g of pure water, stirred uniformly with a glass rod, and fully dissolved to form a mixed aqueous solution a;
[0083] b. 30 g of halloysite and 50 g of citric acid were dissolved in 200 g of pure water, and stirred vigorously at room temperature of 25°C for 5 min to form a mixed solution b;
[0084] c. The mixed solution a was added dropwise to the mixed solution b, and mechanically stirred at room temperature of 25°C for 10 min to obtain a solution containing the target product;
[0085] d. The product was centrifuged and washed with pure water for 4 times, dried at 100°C for 24 h, and ground to obtain the interface-assembled modified halloysite powder 3;
[0086] e. 2 g of the interface-assembled modified halloysite powder 3 was mixed with 98 g of polylactic acid master batch by a direct melt blending method through an internal mixer to prepare a polylactic acid composite material, and a flat vulcanizing machine was used to press it into a test standard sample, which was recorded as PLA-5.
[0087] Example 4
[0088] Preparation of interface-assembled modified halloysite powder 4 and its polymer composite test sample PLA-6
[0089] a. 20 g of piperazine and 14 g of NiSO4·6H2O were dissolved in 300 g of pure water, stirred uniformly with a glass rod, and fully dissolved to form a mixed solution a;
[0090] b. 30 g of halloysite and 42 g of oxalic acid were dissolved in 200 g of pure water, and stirred vigorously at room temperature of 25°C for 5 min to form a mixed solution b;
[0091] c. The mixed solution a was added dropwise to the mixed solution b, and mechanically stirred at room temperature of 25°C for 10 min to obtain a solution containing the target product;
[0092] c. The product was centrifuged, washed with pure water for 4 times, dried at 100°C for 24 h, and ground to obtain the interface-assembled modified halloysite powder 4;
[0093] d. 2 g of the interface-assembled modified halloysite powder 4 and 98 g of polylactic acid master batch were directly melt blended by a banbury mixer to prepare a polylactic acid composite material, and a flat vulcanizing machine was used to press it into a test standard sample, which was recorded as PLA-6.
[0094] Example 5
[0095] Preparation of interface-assembled modified halloysite powder 5 and its polymer composite test sample PLA-7
[0096] a. 25 g of melamine and 13.5 g of CoCl2·6H2O were dissolved in 300 g of pure water, stirred uniformly with a glass rod, and fully dissolved to form a mixed solution a;
[0097] b. 30 g of halloysite and 50 g of itaconic acid were dissolved in 200 g of pure water, and stirred vigorously at room temperature of 25°C for 5 min to form a mixed solution b;
[0098] c. The mixed solution a was added dropwise to the mixed solution b, and mechanically stirred at room temperature of 25°C for 10 min to obtain a solution containing the target product;
[0099] d. The product was centrifuged, washed with pure water for 4 times, dried at 100°C for 24 h, and ground to obtain the interface-assembled modified halloysite powder 5;
[0100] e. 2 g of the interface-assembled modified halloysite powder 5 and 98 g of polylactic acid master batch were directly melt blended by a banbury mixer to prepare a polylactic acid composite material, and a flat vulcanizing machine was used to press it into a test standard sample, which was recorded as PLA-7.
[0101] Example 6
[0102] The halloysite pure sample and the interface-assembled modified halloysite powders 1-5 prepared in Examples 1-5 were taken, and a full-automatic specific surface and porosity analyzer was used to test the specific surface area and pore size of the powders, and the results are shown in Table 1.
[0103] Table 1 Test sample specific surface area and pore diameter experimental data
[0104] Nanomaterials Specific surface area (m 2 / g) Pore diameter (nm) Hormite pure sample 45.501～45.612 23.001～23.159 Interface assembled modified hormite powder 1 49.205～49.367 12.114～12.404 Interface assembled modified hormite powder 2 50.152～50.158 11.022～11.131 Interface assembled modified hormite powder 3 52.403～52.603 9.031～9.132 Interface assembled modified hormite powder 4 47.662～47.674 12.331～12.652 Interface assembled modified hormite powder 5 51.101～51.202 15.113～15.423
[0105] As shown in Table 1, the specific surface area of the interface assembled modified halloysite of the application is obviously larger than that of the pure halloysite sample, and the pore diameter is obviously smaller. Figure 2a is a transmission electron microscope image of the pure halloysite sample, Figure 2b is a transmission electron microscope image of the interface assembled modified halloysite prepared in Example 1. Comparison Figure 2a and Figure 2b From the transmission electron microscope images of the two kinds of halloysite in and, it can be seen that the interface assembled modified halloysite of the application has a larger outer diameter and a smaller inner diameter, which is consistent with the test data in Table 1, proving that the modifier is successfully assembled on the inner and outer surfaces of the halloysite nanotube.
[0106] Figure 3a is a scanning electron microscope image of the brittle fracture surface of the halloysite-based nanocomposite prepared in Comparative Example 2, Figure 3b is a scanning electron microscope image of the brittle fracture surface of the interface assembled modified halloysite-based nanocomposite prepared in Example 1. Comparison Figure 3a and Figure 3b From the scanning electron microscope images of the brittle fracture surfaces of the two kinds of halloysite-based nanocomposites in and, it can be seen that the pure halloysite powder in the polymer has obvious agglomeration, while the interface assembled modified halloysite of the application is uniformly dispersed in the polymer, which indicates that the modifier is assembled on the inner and outer surfaces of the halloysite nanotube, which can effectively improve the dispersibility of the nanomaterial and greatly reduce the agglomeration.
[0107] Example 7
[0108] The control samples prepared in Comparative Examples 1 and 2 and the interface assembled modified halloysite-based composites prepared in Examples 1-5 were subjected to mechanical property (tensile test and pendulum test), smoke release (cone calorimeter), and electromagnetic shielding performance test analysis, and the results are shown in Table 2. Among them, the mechanical properties of breaking strength and elongation at break were tested by tensile test according to GB / T 1040 standard; the impact strength was tested by pendulum test according to GB / T1043.1-2008 standard; the smoke release amount was tested in the cone calorimeter according to GB / 16172 standard; and the total electromagnetic shielding value was tested on the microwave network vector analyzer according to the waveguide method.
[0109] Table 2 Test sample smoke release amount, breaking strength and elongation at break, impact strength, and total electromagnetic shielding value experimental data
[0110]
[0111] As shown in Table 2, compared with pure polylactic acid resin and halloysite-based nanocomposite, the interface assembly modified halloysite-based composite of the application significantly reduces the total smoke release amount, significantly improves the breaking strength and elongation at break and impact strength, and the total electromagnetic shielding value is also significantly higher, which shows that due to the addition of the interface assembly modified halloysite, the smoke suppression performance, mechanical properties-breaking strength and elongation at break, impact strength and electromagnetic shielding performance of the polylactic acid composite are significantly improved.
[0112] The above is only a specific application example of the application, and does not constitute any limitation on the protection scope of the application. Any technical solutions formed by equivalent transformation or equivalent replacement fall within the protection scope of the application.
Claims
1. An interface assembly modified halloysite nanotube, comprising: The hollow halloysite nanotube is loaded with a layer of modified material on the outer surface of the halloysite nanotube and is also loaded with a layer of modified material on the inner cavity surface of the halloysite nanotube, wherein the interface assembly modified halloysite nanotube is prepared by the following method. A certain amount of amino compound is mixed with metal ion aqueous solution to form a complex mixed solution a for standby; Halloysite nanotubes are mixed with a certain amount of carbon-containing organic acid aqueous solution, and stirred uniformly at room temperature 15-30℃ to form a complex mixed solution b for standby; The complex mixed solution a is slowly added to the complex mixed solution b, and stirred for 5-20 minutes at room temperature 15-30℃; After centrifugal washing, drying and grinding, the product is obtained.
2. The interfacial assembly modified hallosite nanotube according to claim 1, wherein, The carbon-containing organic acid is at least one of phytic acid, tannic acid, oxalic acid, azelaic acid, fumaric acid, citric acid, vanillic acid, coffee acid and itaconic acid; the amino compound is at least one of melamine, nicotinamide, piperazine, diphenylamine, p-toluidine, triphenylamine and tertiary octylamine; and the metal ion aqueous solution is at least one of FeCl3·6H2O, CoCl2·6H2O, NiSO4·6H2O and CuCl2·2H2O.
3. A preparation method of the interface assembly modified halloysite nanotube according to claim 1 or 2, comprising: A certain amount of amino compound is mixed with metal ion aqueous solution to form a complex mixed solution a for standby; Halloysite nanotubes are mixed with a certain amount of carbon-containing organic acid aqueous solution, and stirred uniformly at room temperature 15-30℃ to form a complex mixed solution b for standby; The complex mixed solution a is slowly added to the complex mixed solution b, and stirred for 5-20 minutes at room temperature 15-30℃; After centrifugal washing, drying and grinding, the product is obtained.
4. The production process according to claim 3, wherein The amino compound is at least one of melamine, nicotinamide, piperazine, diphenylamine, p-toluidine, triphenylamine and tertiary octylamine; the metal ion aqueous solution is at least one of FeCl3·6H2O, CoCl2·6H2O, NiSO4·6H2O and CuCl2·2H2O; and the carbon-containing organic acid is at least one of phytic acid, tannic acid, oxalic acid, azelaic acid, fumaric acid, citric acid, vanillic acid, coffee acid and itaconic acid.
5. The production process according to claim 3, wherein The amino compound, the metal ion compound and water are prepared into the complex mixed solution a according to the mass ratio of (1-2):1:(20-25).
6. The method of preparation according to claim 3, wherein, The halloysite, the carbon-containing organic acid and water are prepared into the complex mixed solution b according to the mass ratio of 1:(1-2):(6-7).
7. A process of preparation according to any one of claims 3 to 6 wherein, The mass ratio of the complex mixed solution a to the complex mixed solution b is (1-2):
1.
8. An interface assembly modified halloysite-based nanocomposite material, comprising the interface assembly modified halloysite nanotube according to claim 1 or 2 and a polymer, wherein the polymer is an impact-resistant engineering plastic, rubber or polyurethane.
9. The interfacial assembly modified hallosite based nanocomposite according to claim 8, wherein, The interface assembly modified halloysite nanotube accounts for 2wt%-15wt% of the total weight of the composite material; the impact-resistant engineering plastic is polyethylene, polylactic acid, polypropylene or polyvinyl chloride; and the rubber is ethylene-propylene-diene or nitrile rubber.
10. A process for the preparation of an interfacially assembled modified halloysite based nanocomposite as claimed in claim 8 or 9, comprising: In an internal mixer, the interface assembly modified halloysite nanotubes are melt-blended with polymers to obtain.