A high-transparency, high-hardness, high-toughness composite material with a nano-organic-inorganic hybrid interpenetrating network structure and a preparation method thereof

Abstract

The present invention belongs to the field of nanocomposite materials, and specifically relates to a highly transparent, high-hardness, and high-toughness composite material having a nano-organic-inorganic hybrid interpenetrating network structure and a preparation method thereof. The composite material comprises a polymer nanofiber network skeleton and an organic-inorganic hybrid nanofluid, wherein the organic-inorganic hybrid nanofluid and the polymer nanofiber network skeleton interpenetrate each other and cross-link and solidify to form an interpenetrating network structure. The nano-organic-inorganic hybrid interpenetrating network structure proposed in the present invention achieves an organic combination of high transparency, high hardness, and high toughness, especially for composite materials with a thickness exceeding 100 μm, showing potential for wide application in consumer electronics, optical devices, automobile manufacturing, architectural furniture, aerospace, and other fields.

Description

Technical Field

[0001] The present invention belongs to the field of nanocomposite materials, and in particular relates to a high-transparency, high-hardness, high-toughness composite material with a nano organic-inorganic hybrid interpenetrating network structure and a preparation method thereof. Background Art

[0002] Materials with high transparency, high hardness and high toughness have shown important application value in the fields of consumer electronics, optical devices, automobile manufacturing, architectural furniture, and aerospace. However, traditional material systems have obvious limitations: metal materials generally lack optical transparency; although inorganic non-metallic materials have high hardness and high modulus, they are prone to stress concentration under the action of external forces due to their intrinsic brittleness, leading to crack extension and brittle failure; and although organic polymer materials have excellent toughness, transparency and processing properties, they are limited by their lower hardness and modulus. By constructing an organic-inorganic hybrid composite material system, the advantages of the two types of components can be effectively integrated - while retaining the toughness and processing properties of the polymer material, the hardness and modulus can be significantly improved. However, to achieve the coordinated optimization of these properties, it is necessary to precisely control the composition and microstructure of the composite material, and its design and preparation still face major challenges.

[0003] The current mainstream structures of organic-inorganic hybrid composite materials can be divided into three categories (such as Figure 1 As shown): The first type is the inorganic particle-enhanced structure (Structure I), in which inorganic particles are uniformly / randomly dispersed in a polymer matrix to improve mechanical properties. However, as the content of inorganic components increases, the transparency and toughness of the composite material will decrease sharply; the second type is the continuous filler network structure (Structure II), which, by constructing a continuous inorganic network running through the matrix, enhances the mechanical properties while giving the material thermal / electrical conductivity. However, since the characteristic size of the network generally exceeds the wavelength of visible light, this type of structure usually results in opaque materials; the third type is the "shell-like" layered structure (Structure III), which achieves a strength-toughness balance through the alternating stacking of organic components and inorganic sheets. However, it is difficult to achieve both transparency and processing due to the limitations of the stacking density of the inorganic layers and the difference in refractive index between the organic and inorganic phases. In addition, the large-scale processing problem of this system has not been overcome for a long time.

[0004] Although the invention patent (CN202510154760.6) discloses an ultra-flexible, ultra-thin hybrid glass film, this strategy can only achieve a transmittance of over 90% within a thickness range of less than 50 μm. As the thickness increases, the differences in refractive index among the multiphase and multicomponent components within the composite material and the inherent poor transmittance will lead to a significant decrease in the material's optical transparency (for example, the transmittance of a 100 μm thick material drops to 80%), making it impossible to prepare highly transparent, high-hardness, and high-toughness materials at greater thicknesses (e.g., above 100 μm). In addition, because the oligomeric silsesquioxane used in the material is prepared by hydrolysis of trifunctional (T-type) siloxane, the material's network has low crosslinking density and rigidity, with hardness and modulus exceeding 5 GPa and 30 GPa, respectively, which is still a significant gap compared to inorganic materials.

[0005] So far, the preparation of high-transparency, high-hardness, and high-toughness composite materials with larger thickness, such as in the range of 50-600μm, is still a technical bottleneck that needs to be broken through in this field. Summary of the Invention

[0006] To address these issues, the present invention proposes a composite material with a nanoscale organic-inorganic hybrid interpenetrating network structure. This material not only exhibits high transparency, high hardness, and high toughness, but also boasts significant advantages such as a simple preparation process and ease of large-scale processing.

[0007] The technical solution of the present invention:

[0008] In the first aspect, the present invention provides a highly transparent, high hardness, and high toughness composite material having a nano organic-inorganic hybrid interpenetrating network structure, wherein the composite material comprises a polymer nanofiber network skeleton and an organic-inorganic hybrid nanofluid, wherein the organic-inorganic hybrid nanofluid and the polymer nanofiber network skeleton are interconnected and cross-linked and cured to form an interpenetrating network structure, and the specific structure is as follows Figure 1 (Structure IV) is shown.

[0009] Furthermore, the thickness of the polymer nanofiber network skeleton is 0.5 μm to 600 μm or higher and the composite material has a light transmittance greater than 90%.

[0010] Furthermore, the polymer nanofiber network skeleton includes at least one of polyethylene (PE), polypropylene (PP), cyclic polyolefin (COC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PBN), polycarbonate (PC), polyamide (PA), polyimide (PI), polyethersulfone (PES), polyetheretherketone (PEEK), polyurethane (PU), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF) nanofiber network skeletons.

[0011] Furthermore, the preparation method of the polymer nanofiber network skeleton includes at least one of dry method, wet method uniaxial / biaxial stretching, electrospinning or melt blowing.

[0012] Furthermore, the fiber diameter of the polymer nanofiber network skeleton is 10 nanometers to 200 nanometers.

[0013] Furthermore, in the composite material, there is a continuous phase and a large number of nanopores between the polymer nanofiber networks.

[0014] Furthermore, the diameter of the nanopores in the polymer nanofiber network skeleton is 10 nanometers to 300 nanometers.

[0015] Furthermore, the porosity of the polymer nanofiber network skeleton is 20-90%, and more preferably 50-80%.

[0016] Furthermore, the thickness of the polymer nanofiber network skeleton is 0.5 μm to 600 μm, preferably 50 μm to 600 μm.

[0017] Furthermore, the organic-inorganic hybrid nanofluid is formed by compounding liquid silicone resin and inorganic nanoparticles.

[0018] Furthermore, the organic-inorganic hybrid nanofluid has good fluidity, can form an interpenetrating continuous phase after being compounded with the above-mentioned polymer nanofiber network skeleton, and has chemical reaction activity, and can construct a cross-linked network structure through chemical reaction.

[0019] Furthermore, the liquid silicone resin is selected from liquid MT, MDT, MDQ, MDTQ, MTQ, MQ, DT, DQ, DTQ or TQ silicone resin.

[0020] Furthermore, the liquid silicone resin comprises the following basic repeating units:

[0021]

[0022] Wherein, R is an organic group.

[0023] Furthermore, the organic group includes one or more combinations of epoxy groups, amino groups, acrylate groups, methacrylate groups, vinyl groups, mercapto groups, hydrogen-containing groups, isocyanate groups, hydroxyl groups, alkoxy groups, and the like.

[0024] Furthermore, the inorganic nanoparticles are at least one of silicon dioxide, titanium dioxide, aluminum oxide, and zirconium oxide particles, or a graded mixture thereof.

[0025] Furthermore, the particle size of the inorganic nanoparticles is 1-200 nanometers.

[0026] Furthermore, the inorganic nanoparticles have reactive functional groups on their surfaces and are capable of chemically reacting with the liquid silicone resin.

[0027] Furthermore, the cross-linking and curing is initiated by an initiator.

[0028] Furthermore, the initiator includes at least one of a thermal initiator, triethylamine, a platinum catalyst or a photoinitiator.

[0029] Furthermore, the thermal initiator includes at least one of azobisisobutyronitrile, azobisisobutyramidine hydrochloride or azobisisopropylimidazoline hydrochloride, or a mixture of the above thermal initiators.

[0030] Furthermore, the photoinitiator includes at least one of 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, benzoin dimethyl ether, triphenylsulfonium hexafluoroantimonate or 2,2-diethoxyacetophenone, a platinum catalyst, or a mixture of the above photoinitiators.

[0031] In a second aspect, the present invention provides a method for preparing a highly transparent, high hardness, and high toughness composite material having a nano-organic-inorganic hybrid interpenetrating network structure as described herein, comprising the following steps:

[0032] (1) Preparation of polymer nanofiber network skeleton with nanopores;

[0033] (2) Surface modification of inorganic nanoparticles to introduce reactive functional groups, and then fully mixing the modified inorganic nanoparticles with liquid silicone resin to obtain optically transparent organic-inorganic hybrid nanofluids;

[0034] (3) The organic-inorganic hybrid nanofluid obtained in step (2) is compounded with the polymer nanofiber network skeleton obtained in step (1), and cross-linked and cured to obtain a composite material having a nano organic-inorganic hybrid interpenetrating network structure.

[0035] Furthermore, the preparation method of the polymer nanofiber network skeleton with nanopores includes at least one of dry and wet uniaxial / biaxial stretching, electrospinning, and melt blowing.

[0036] Furthermore, the thickness of the prepared polymer nanofiber network skeleton is 0.5 μm to 600 μm, preferably 50 μm to 600 μm.

[0037] Furthermore, the fiber diameter of the prepared polymer nanofiber network skeleton is 10 nanometers to 200 nanometers.

[0038] Furthermore, methods for surface modification of inorganic nanoparticles are well known in the art, and those skilled in the art can routinely select the reactive functional groups to be introduced according to practical applications.

[0039] Furthermore, step (2) further comprises mixing the initiator with the inorganic nanoparticles and the liquid silicone resin.

[0040] Furthermore, the mixing is performed in a solvent.

[0041] Furthermore, the solvent includes at least one of the following substances: dichloromethane, chloroform, toluene, xylene, ether, tetrahydrofuran, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, acetonitrile, benzonitrile, methanol or ethanol.

[0042] Furthermore, step (2) also includes removing the solvent after the mixing is completed.

[0043] Furthermore, the mass ratio of the liquid silicone resin to the inorganic nanoparticles is 5-90:10-80, preferably 20-75:20-80.

[0044] In the present invention, one of the key features of the highly transparent, high hardness, and high toughness composite material having a nano-organic-inorganic hybrid interpenetrating network structure is that the diameter of the nanofibers is less than 200 nm, which is much smaller than the wavelength of visible light, so that the composite material still has high transparency at a large thickness of 50 to 600 μm, and the hardness and toughness of the composite material are regulated by the type, diameter, nanopore size and content of the polymer nanofiber network skeleton, and the type and content of MT, MDT, MDQ, MDTQ, MTQ, MQ, DT, DQ, DTQ and TQ silicone resins and inorganic nanoparticles in the organic-inorganic hybrid nanofluid.

[0045] Furthermore, the curing includes light curing or heat curing.

[0046] Furthermore, the heating and curing is carried out at 50-100°C.

[0047] In the present invention, the highly transparent, high hardness, and high toughness composite material having a nano-organic-inorganic hybrid interpenetrating network structure can be applied to consumer electronics, optical devices, automobile manufacturing, architectural furniture, aerospace, and other fields.

[0048] Advantageous Effects of the Invention

[0049] Compared with the prior art, the present invention has the following beneficial effects: providing a high-transparency, high-hardness, and high-toughness composite material having a novel nano-organic-inorganic hybrid interpenetrating network structure. The novel organic-inorganic hybrid structure refers to an interpenetrating network structure formed by a continuous polymer nanofiber network skeleton and an organic-inorganic hybrid nanofluid containing inorganic nanoparticles that interpenetrate and crosslink and solidify. The high-transparency, high-hardness, and high-toughness composite material having a nano-organic-inorganic hybrid interpenetrating network structure is prepared by first constructing a polymer nanofiber network skeleton with a large number of nanopores, and then interpenetrating and crosslinking and solidifying the organic-inorganic hybrid nanofluid mixed with inorganic nanoparticles with the polymer nanofiber network skeleton. The polymer nanofiber network skeleton and the organic-inorganic hybrid nanofluid are two continuous phases in the composite material. The polymer nanofiber network skeleton phase provides the composite material with energy dissipation capacity and exhibits excellent toughness. The organic-inorganic hybrid nanofluid containing inorganic nanoparticles provides the material with high hardness and high modulus after crosslinking and solidification, and can effectively inhibit fatigue relaxation of the organic component, thereby improving the durability of the composite material. By regulating the type, diameter, nanopore size, and content of the polymer nanofiber network backbone, as well as the type and content of the organic-inorganic hybrid nanofluid, the material's transparency, hardness, and toughness can be controlled. The highly transparent, high-strength, and high-toughness composite material with a nanoscale organic-inorganic hybrid interpenetrating network structure provided by this invention has applications in consumer electronics, optical devices, automotive manufacturing, architectural furniture, and aerospace. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings described herein are intended to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0051] Figure 1 They are three mainstream organic-inorganic hybrid structures (structures I, II, and III) and the nano organic-inorganic hybrid interpenetrating network structure (structure IV) described in the present invention.

[0052] Figure 2 This is a flow chart for preparing a highly transparent, high-hardness, and high-toughness composite material having a nanostructured organic-inorganic hybrid interpenetrating network. First, a polymer nanofiber network skeleton with numerous nanopores is constructed. Then, an organic-inorganic hybrid nanofluid and the polymer nanofiber network skeleton are interpenetrated and cross-linked to produce a highly transparent, high-strength, and high-toughness composite material having a nanostructured organic-inorganic hybrid interpenetrating network.

[0053] Figure 3 This is the visible spectrum experimental result of the composite material with a nano-organic-inorganic hybrid interpenetrating network structure prepared in Example 5 of the present invention. The composite material has a thickness of 600 μm and a transmittance of 93%. DETAILED DESCRIPTION

[0054] The present invention is further illustrated below with reference to specific examples, which are not intended to limit the present invention in any manner. Unless otherwise specified, the reagents, methods, and equipment employed in the present invention are conventional in the art. In the following examples, the preparation methods of liquid MT, MDT, MDQ, MDTQ, MTQ, MQ, DT, DQ, DTQ, and TQ organosilicon resins and the inorganic nanoparticles employed are widely documented and will not be further illustrated here.

[0055] Example 1

[0056] (1) A polyethylene nanofiber network skeleton with a large number of nanopores was prepared by wet biaxial stretching. First, 10 parts of polyethylene and 90 parts of white oil were mixed evenly to prepare a polyethylene white oil blend, which was then pressed into a 10 cm thick sheet. Subsequently, the sheet was biaxially stretched at a high temperature of 180 °C with a stretching ratio of 15×15. After washing with n-hexane and drying, a polyethylene nanofiber network skeleton with a thickness of 100 μm, a porosity of 50%, and a fiber diameter of approximately 50 nm was obtained.

[0057] (2) By mass, epoxy TQ-type silicone resin (75 parts) with a molecular weight of 2000, epoxy-modified silica nanoparticles (20 nm, 25 parts), initiator (triphenylsulfonium hexafluoroantimonate, 1 part) and ethyl acetate (solvent, 50 parts) were mixed uniformly. After removing the ethyl acetate, a transparent and viscous slurry A was formed.

[0058] (3) Slurry A is soaked in the polyethylene nanofiber network skeleton so that the slurry and the polyethylene nanofiber network skeleton interpenetrate each other. After UV curing (365 nm) for 3 minutes, the target composite material is obtained.

[0059] Example 2

[0060] The difference from Example 1 is that in step 2, the epoxy TQ-type silicone resin is replaced with 50 parts and the silica nanoparticles are replaced with 50 parts.

[0061] Example 3

[0062] The difference from Example 1 is that in step 2, the epoxy TQ-type silicone resin is replaced with 25 parts and the silica nanoparticles are replaced with 75 parts.

[0063] Example 4

[0064] The difference from Example 1 is that in step 1, the stretching ratio is replaced with 10×10, and after washing with n-hexane and drying, the polyethylene nanofiber network skeleton is obtained with a thickness of about 300 μm, a porosity of 50%, and a fiber diameter of about 80 nm.

[0065] Example 5

[0066] Different from Example 1, in step 1, the stretching ratio is replaced with 7×7. After washing with n-hexane and drying, the polyethylene nanofiber network skeleton is obtained with a thickness of about 600 μm, a porosity of 50%, and a fiber diameter of about 120 nm.

[0067] Example 6

[0068] Different from Example 5, in step 1, the 10 parts of polyethylene and 90 parts of white oil are replaced by 20 parts of polyethylene and 80 parts of white oil, resulting in a polyethylene nanofiber network skeleton with a thickness of about 700 μm, a porosity of 40%, and a fiber diameter of about 150 nm.

[0069] Example 7

[0070] Different from Example 5, in step 1, the 10 parts of polyethylene and 90 parts of white oil are replaced by 5 parts of polyethylene and 95 parts of white oil, resulting in a polyethylene nanofiber network skeleton with a thickness of about 400 μm, a porosity of 60%, and a fiber diameter of about 100 nm.

[0071] Example 8

[0072] The difference from Example 1 is that in step 2, the particle size of the nano-silica is replaced with ~80 nm.

[0073] Example 9

[0074] The difference from Example 1 is that in step 2, the particle size of the nano-silica is replaced with ~180 nm.

[0075] Example 10

[0076] The difference from Example 5 is that in step 2, the epoxy TQ type silicone resin is replaced by an epoxy DTQ type silicone resin.

[0077] Example 11

[0078] The difference from Example 5 is that in step 2, the epoxy-based TQ-type silicone resin is replaced by an epoxy-based DT-type silicone resin.

[0079] Example 12

[0080] The difference from Example 5 is that in step 2, the epoxy-based TQ-type silicone resin is replaced by an epoxy-based DQ-type silicone resin.

[0081] Example 13

[0082] The difference from Example 5 is that in step 2, the epoxy-based TQ-type silicone resin is replaced by an epoxy-based MQ-type silicone resin.

[0083] Example 14

[0084] The difference from Example 5 is that in step 2, the epoxy TQ type silicone resin is replaced by an epoxy MTQ type silicone resin.

[0085] Example 15

[0086] The difference from Example 5 is that in step 2, the epoxy-based TQ-type silicone resin is replaced by an epoxy-based MDTQ-type silicone resin.

[0087] Example 16

[0088] The difference from Example 5 is that in step 2, the epoxy-based TQ-type silicone resin is replaced by an epoxy-based MDQ-type silicone resin.

[0089] Example 17

[0090] The difference from Example 5 is that in step 2, the epoxy-based TQ-type silicone resin is replaced by an epoxy-based MDT-type silicone resin.

[0091] Example 18

[0092] The difference from Example 5 is that in step 2, the epoxy-based TQ-type silicone resin is replaced by an epoxy-based MT-type silicone resin.

[0093] Example 19

[0094] The difference from Example 3 is that in step 2, the epoxy TQ-type silicone resin (25 parts) is replaced with epoxy (12.5 parts) and amino (12.5 parts) TQ-type silicone resin; in step 3, the curing method is 80° C. reaction for 2 hours.

[0095] Example 20

[0096] Different from Example 3, in step 2, the epoxy TQ-type silicone resin (25 parts) was replaced by acrylate (12.5 parts) and mercapto (12.5 parts) TQ-type silicone resins, and the initiator was 2-hydroxy-2-methylphenyl acetone (1 part).

[0097] Example 21

[0098] Different from Example 3, in step 2, the epoxy-based TQ-type silicone resin (25 parts) was replaced by an acrylate-based TQ-type silicone resin (25 parts), and the initiator was azobisisobutyronitrile (0.5 parts).

[0099] Example 22

[0100] Different from Example 3, in step 2, the epoxy-based TQ-type silicone resin (25 parts) was replaced by a methacrylate-based TQ-type silicone resin (25 parts), and the initiator was azobisisobutyronitrile (0.5 parts).

[0101] Example 23

[0102] The difference from Example 3 is that the epoxy TQ-type silicone resin in step 2 is replaced by vinyl TQ-type silicone resin (12.5 parts) and hydrogen-containing TQ-type silicone resin (12.5 parts), and the initiator is a platinum catalyst (0.2 parts); in step 3, the curing method is 100°C for 4 hours.

[0103] Example 24

[0104] Different from Example 3, in step 2, the epoxy TQ type silicone resin (25 parts) was replaced with isocyanate (12.5 parts) and hydroxyl (12.5 parts) TQ type silicone resin, and the curing conditions were 80° C. for 3 h.

[0105] Example 25

[0106] The difference from Example 3 is that in step 2, the epoxy TQ-type silicone resin (25 parts) is replaced by an alkoxy TQ-type silicone resin (25 parts), and the curing condition is 80° C. for 10 h.

[0107] Example 26

[0108] (1) A polypropylene nanofiber network skeleton with a large number of nanopores was prepared by wet biaxial stretching. First, 80 parts of polypropylene and 20 parts of white oil were mixed evenly to prepare a polyethylene white oil blend, which was then pressed into a 10 cm thick cast sheet. Subsequently, the cast sheet was biaxially stretched at a high temperature of 200 °C with a stretching ratio of 15×15. After washing with n-hexane and drying, a polypropylene nanofiber network skeleton with a thickness of 400 μm, a porosity of 60%, and a fiber diameter of approximately 100 nm was obtained.

[0109] (2) By mass, epoxy TQ-type silicone resin (25 parts) with a molecular weight of 2000, epoxy-modified silica nanoparticles (75 parts), initiator (triphenylsulfonium hexafluoroantimonate, 1 part) and ethyl acetate (solvent, 50 parts) were mixed uniformly. After removing the ethyl acetate, a transparent and viscous slurry A was formed.

[0110] (3) Slurry A is soaked in the polypropylene nanofiber network skeleton so that the slurry and the polypropylene nanofiber network skeleton interpenetrate each other. After UV curing (365 nm) for 3 minutes, the target composite material is obtained.

[0111] Example 27

[0112] The difference from Example 26 is that the polypropylene nanofiber network skeleton is replaced by a cyclic polyolefin nanofiber network skeleton, and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0113] Example 28

[0114] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced with polyethylene terephthalate (PET), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0115] Example 29

[0116] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced with polybutylene terephthalate (PBT), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0117] Example 30

[0118] The difference from Example 27 is that the cyclic polyolefin nanofiber network skeleton is replaced with polyethylene naphthalate (PBN), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0119] Example 31

[0120] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced by polyamide (PA), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0121] Example 32

[0122] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced by polyimide (PI), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0123] Example 33

[0124] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced with polysulfone (PSF), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0125] Example 34

[0126] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced with polyethersulfone (PES), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0127] Example 35

[0128] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced with polyetheretherketone (PEEK), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0129] Example 36

[0130] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced by polyurethane (PU), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0131] Example 37

[0132] The difference from Example 27 is that the cyclic polyolefin nanofiber network skeleton is replaced with polytetrafluoroethylene (PTFE), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0133] Example 38

[0134] Different from Example 27, the cyclic polyolefin nanofiber network skeleton is replaced with polyvinylidene fluoride (PVDF), and the preparation method is electrospinning. The thickness is 400 μm, the fiber diameter is 150 nm, and the porosity is 60%.

[0135] Example 39

[0136] The difference from Example 3 is that in step 2, the nano-silica is replaced by titanium dioxide (particle size ~20 nm).

[0137] Example 40

[0138] The difference from Example 3 is that in step 2, the nano-silica is replaced by aluminum dioxide (particle size ~20 nm).

[0139] Example 41

[0140] The difference from Example 3 is that in step 2, the nano-silicon dioxide is replaced by zirconium dioxide (particle size ~20 nm).

[0141] Comparative Example 1

[0142] The difference from Example 1 is that in step 2, the epoxy TQ-type silicone resin with a molecular weight of 2000 is replaced with 100 parts, and silicon dioxide is not added.

[0143] Comparative Example 2

[0144] Different from Example 1, in step 3, the polyethylene nanofiber network skeleton used has a thickness of 50 μm, a porosity of about 50%, and a fiber diameter of about 230 nm.

[0145] Comparative Example 3

[0146] Different from Example 1, in step 3, the polyethylene nanofiber network skeleton used has a thickness of 50 μm, a porosity of about 50%, and a fiber diameter of about 300 nm.

[0147] Test Method

[0148] The performance tests were conducted on the composite materials having nano-organic-inorganic hybrid interpenetrating network structures prepared in Examples 1-41 and Comparative Examples 1-3. The specific performance test methods are as follows:

[0149] (1) Light transmittance test

[0150] The transmittance characterization was tested by the UV-3600 UV-visible light tester produced by Shimadzu Corporation of Japan.

[0151] (2) Hardness test

[0152] The hardness characterization comes from nanoindentation testing, which is done using a Piuma nanoindenter from Optics11 of the Netherlands.

[0153] (3) Modulus test

[0154] The modulus characterization comes from the tensile test, and the tensile stress-strain curve is measured by an EM6.501-W tensile testing machine from Tesmart, Shenzhen, China.

[0155] (4) Elongation at break test

[0156] The elongation at break was characterized by tensile testing, and the tensile stress-strain curve was measured by an EM6.501-W tensile testing machine from Tesmart, Shenzhen, China.

[0157] (5) Strength test

[0158] Strength characterization comes from tensile testing, and the tensile stress-strain curves are tested by an EM6.501-W tensile testing machine from Tesmart, Shenzhen, China.

[0159] Among them, the high transparency, high strength and high toughness composite material with nano organic-inorganic hybrid interpenetrating network structure prepared in Example 5 was evaluated in the transmittance experiment. The specific results are as follows Figure 3 As shown, Figure 3 In the embodiment 5, the high-transparency, high-hardness and high-toughness composite material with a nano-organic-inorganic hybrid interpenetrating network structure prepared has a high transmittance, indicating that the nano-organic-inorganic hybrid interpenetrating network structure provided by the present invention can effectively achieve high transparency of the composite material.

[0160] The results of the performance tests on the materials prepared in Examples 1-41 and Comparative Examples 1-3 are detailed in Table 1 below.

[0161] Table 1. Performance test results of high transparency, high hardness and high toughness composite materials

[0162] Thickness (μm) Transmittance (%) Hardness (GPa) Modulus (GPa) Elongation at break (%) Strength (MPa) Example 1 100 98 3 20 40 600 Example 2 100 97 5.5 29 30 550 Example 3 100 97 7 41 20 450 Example 4 300 96 3 18 50 580 Example 5 600 93 3 17 60 500 Example 6 700 89 2.9 15 70 480 Example 7 400 94 3 17 54 540 Example 8 100 96 4 25 35 580 Example 9 100 93 5 28 30 550 Example 10 600 93 2.9 16.5 62 480 Example 11 600 93 2.8 15 63 470 Example 12 600 93 2.7 14 65 465 Example 13 600 93 2.6 13.6 66 460 Example 14 600 93 2.5 13 67 450 Example 15 600 93 2.45 12.8 68 440 Example 16 600 93 2.4 12.3 70 420 Example 17 600 93 2.36 12 71 408 Example 18 600 93 2.2 11 75 390 Example 19 100 98 7.2 42 22 500 Example 20 100 97 6.9 38 23 480 Example 21 100 98 7.3 44 20 478 Example 22 100 97 7.2 42 18 470 Example 23 100 97 7.5 45 15 560 Example 24 100 98 6.8 36 30 410 Example 25 100 96 7.6 46 15 380 Example 26 400 96 7.1 20 40 600 Example 27 400 96 7 25 36 680 Example 28 400 96 7 10 30 580 Example 29 400 96 7 8 36 550 Example 30 400 96 7 15 20 600 Example 31 400 96 7 18 25 650 Example 32 400 96 7 17 24 640 Example 33 400 96 7 25 15 590 Example 34 400 96 7 30 14 500 Example 35 400 96 7 34 14 470 Example 36 400 96 7 9 60 300 Example 37 400 96 7 11 40 420 Example 38 400 96 7 12 32 450 Example 39 100 97 7.5 43 20 590 Example 40 100 97 8 45 18 579 Example 41 100 97 9 49 17 560 Comparative Example 1 100 98 0.4 3 45 200 Comparative Example 2 50 50 3 2.5 50 170 Comparative Example 3 50 20 3 2.1 60 140

[0163] According to the performance test results of the high-transparency, high-hardness, and high-toughness composite materials having a nano-organic-inorganic hybrid interpenetrating network structure of Examples 1-41 and Comparative Examples 1-3 in Table 1, the present invention first constructs a polymer nanofiber network skeleton with a large number of nanopores, and then the hybrid nanofluid slurry mixed with inorganic nanoparticles and the polymer nanofiber network skeleton are mutually penetrated and cross-linked and cured to obtain a high-transparency, high-hardness, and high-toughness composite material having a nano-organic-inorganic hybrid interpenetrating network structure. The reasons are: first, the fiber diameter of the polymer nanofiber network skeleton (less than 200 nanometers) is much smaller than the wavelength of visible light. After being compounded with the transparent organic-inorganic hybrid nanofluid, even if the thickness increases significantly, it will not affect the transparency of the material; second, the polymer nanofiber network skeleton has excellent flexibility and high orientation, which can avoid stress concentration, thereby giving the composite material excellent toughness, especially elongation at break; third, the organic-inorganic hybrid nanofluid slurry is filled with extremely high inorganic nanoparticles, which form a nanoscale organic-inorganic hybrid cross-linked network after curing, which can give the composite material high hardness and high modulus; fourth, the transparency, hardness and toughness of the composite material can be controlled by regulating the type, diameter, nanopore size and content of the polymer nanofiber network skeleton, the type of hybrid nanofluid, and the type and content of inorganic nanoparticles.

[0164] It should be noted that the preferred embodiments of the present invention are given in the specification and drawings of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of the present invention. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In addition, the above-mentioned technical features can be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the description of the present invention. Furthermore, it is obvious to those skilled in the art that improvements or changes can be made based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A highly transparent, high hardness, and high toughness composite material having a nano-organic-inorganic hybrid interpenetrating network structure, characterized in that: The composite material comprises a polymer nanofiber network skeleton and an organic-inorganic hybrid nanofluid, wherein the organic-inorganic hybrid nanofluid and the polymer nanofiber network skeleton are interconnected and cross-linked and cured to form an interpenetrating network structure; The polymer nanofiber network skeleton comprises at least one of polyethylene, polypropylene, cyclic polyolefin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyamide, polyimide, polyethersulfone, polyetheretherketone, polyurethane, polytetrafluoroethylene, and polyvinylidene fluoride nanofiber network skeletons, and the polymer nanofiber network skeleton has a thickness of 0.5 μm to 600 μm, a fiber diameter of 10 nm to 200 nm, a nanopore diameter of 10 nm to 300 nm, and a porosity of 20 to 90%; The organic-inorganic hybrid nanofluid is composed of a composite of liquid silicone resin and inorganic nanoparticles; The inorganic nanoparticles are at least one of silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide particles or a graded mixture thereof; The particle size of the inorganic nanoparticles is 1-200 nanometers.

2. The composite material according to claim 1, characterized in that The composite material has a light transmittance greater than 90%.

3. The composite material according to claim 1, characterized in that The liquid silicone resin is selected from liquid MT, MDT, MDQ, MDTQ, MTQ, MQ, DT, DQ, DTQ or TQ silicone resin; The liquid silicone resin comprises the following basic repeating units: ； Wherein, R is an organic group, and the organic group includes one or more combinations of epoxy, amino, acrylate, methacrylate, vinyl, mercapto, isocyanate, hydroxyl, and alkoxy groups.

4. The composite material according to claim 1, characterized in that The inorganic nanoparticles have reactive functional groups on their surfaces and are capable of chemically reacting with the liquid organic silicone resin.

5. The composite material according to claim 1, characterized in that The cross-linking curing is initiated by an initiator; The initiator includes at least one of a thermal initiator, triethylamine, a platinum catalyst or a photoinitiator; The thermal initiator includes at least one of azobisisobutyronitrile, azobisisobutyramidine hydrochloride or azobisisopropylimidazoline hydrochloride, or a mixture of the above thermal initiators; The photoinitiator includes at least one of 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, benzoin dimethyl ether, triphenylsulfonium hexafluoroantimonate or 2,2-diethoxyacetophenone, or a mixture of the above photoinitiators.

6. A method for preparing a highly transparent, high hardness, and high toughness composite material having a nano organic-inorganic hybrid interpenetrating network structure according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Preparation of polymer nanofiber network skeleton with nanopores; (2) Surface modification of inorganic nanoparticles to introduce reactive functional groups, and then fully mixing the modified inorganic nanoparticles with liquid silicone resin to obtain optically transparent organic-inorganic hybrid nanofluids; (3) The organic-inorganic hybrid nanofluid obtained in step (2) is compounded with the polymer nanofiber network skeleton obtained in step (1), and cross-linked and cured to obtain a composite material having a nano organic-inorganic hybrid interpenetrating network structure.

7. The preparation method according to claim 6, characterized in that The preparation method of the polymer nanofiber network skeleton with nanopores comprises at least one of dry and wet uniaxial / biaxial stretching, electrostatic spinning, and melt blowing.

8. The preparation method according to claim 6, characterized in that The mixing in step (2) is carried out in a solvent and further comprises mixing the initiator with the inorganic nanoparticles and the liquid silicone resin; The mass ratio of the liquid silicone resin to the inorganic nanoparticles is 5-90:10-80.

9. The preparation method according to claim 8, characterized in that The solvent includes at least one of the following substances: dichloromethane, chloroform, toluene, xylene, ether, tetrahydrofuran, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, acetonitrile, benzonitrile, methanol or ethanol.

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