Three-dimensional impact protection material, preparation method and application thereof

Abstract

The application provides a three-dimensional anti-impact protective material, a preparation method and application thereof, and the three-dimensional anti-impact protective material is prepared from raw materials containing the following components by weight: 5-30 parts of a double-continuous IPN composite material; 60-110 parts of EVA resin; 5-30 parts of polyurethane black and white material; 0.5-5 parts of vulcanizing agent; 5-30 parts of coupling agent; and 0.5-2 parts of foaming agent; the double-continuous IPN composite material is a reticular polymer constructed by mixing and reacting an IHP material containing silicon and boron as a first continuous phase, and one or more of polysiloxane, branched MQ resin or thermoplastic elastomer as a second continuous phase at 60 DEG C for 2-3 hours; the application also provides a preparation method and application of the three-dimensional anti-impact protective material; and the application has the beneficial effects that the reaction temperature is lower than 90 DEG C, and the by-product is less; the prepared material can intelligently respond to external force, has high energy absorption efficiency, good material fatigue resistance and shape stability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of composite materials, and particularly relates to a three-dimensional impact protection material, a preparation method and application thereof. BACKGROUND

[0002] The impact protection material uses the response characteristics of the material to external force to realize intelligent protection of the recipient, and can ensure that the material maintains a soft and comfortable state under normal conditions, but rapidly hardens upon impact of external force, and absorbs and dissipates impact energy, thereby providing effective protection for the recipient. Therefore, the impact protection material has a wide application prospect in sports protection, police protection and material packaging. Traditional impact protection materials include inorganic rigid materials (such as cement, metal materials, etc.), high-strength polymer fibers (such as ultra-high molecular weight polyethylene, Kevlar fiber, etc.), porous foam materials and damping materials (such as polyurethane, cross-linked rubber, etc.), and have been widely used in the protection field. Although the porous foam materials and damping materials have good energy absorption efficiency, these materials have poor fatigue resistance, low energy absorption efficiency and lack of intelligent functions, which leads to the inability to achieve the ideal intelligent protection function we expect. Some materials with a certain degree of external force sensitivity mainly transmit the energy generated by external force when they are in a hardened state, and the energy absorption efficiency is low.

[0003] To solve the above problems, new intelligent protective systems have been designed, among which the shear thickening fluid (STF) system of the US Army Research Laboratory and the DEFLXION series of Dow Corning are the most representative intelligent protective products. Since the US Army Research Laboratory first introduced the "liquid armor" made of STF technology in 2005, the ideal intelligent protective material has gradually become a reality. The STF technology uses inorganic nanoparticles (such as silicon dioxide and calcium carbonate) dispersed in a fluid phase (such as polyethylene glycol) to produce aggregation under external shear, resulting in a unique fluid behavior of sudden viscosity increase. By combining the infiltration of the flow phase in the fiber material, the STF system is compounded inside the fiber material. Then the soft and hard transformation of the composite fiber material (the change in material modulus can reach 2-3 orders of magnitude) under natural and external impact conditions is realized, and most of the impact energy is absorbed by the aggregation and dispersion of a large number of inorganic nanoparticles in the system, ultimately achieving effective protection of the external force receptor. However, due to the limitations of the solventization of the fluid phase in the fiber material and the leakage of the fluid system, the STF system cannot be widely applied in all fiber material fields. The Dow Corning Company uses the swelling flow characteristics of silicon-boron copolymers to prepare swelling materials and composite them with different structure fabrics to develop a series of DEFLXION products for sports functional protective materials. This technology uses functional silane to condense with boric acid under the action of catalyst and high temperature (150-200℃). The swelling material has a certain external force sensitivity under external force, and the external force sensitivity of the material is characterized by the ratio of the elastic modulus of the material at 0.1 Hz and 400 Hz shear frequency (G' max / G' min) in the rheological test, which can reach about 10-500 times. As a famous intelligent protective product in the international market, the appearance of the swelling material has attracted the attention of many people, but the related fundamental scientific research and subsequent innovative development of the product have lagged behind. The swelling material has obvious technical defects while showing good technical characteristics and application potential. For example: 1) The material preparation process requires the presence of toxic and harmful catalysts and high reaction temperature (150-200℃); 2) Under high temperature conditions (100-150℃), boric acid is easily converted into metaboric acid and pyroboric acid, which leads to the presence of many by-products. The by-products produced at lower temperatures have low molecular weight, poor mechanical strength, and easy hydrolysis, which limits the practical application of the product; 3) The material has poor weather resistance at low temperatures (<-20℃), and its performance decreases; 4) The swelling material will break under the action of a large external impact and cannot be repaired actively, which makes the material have poor fatigue resistance. In the actual application process, to improve the forming and processing performance of the swelling material, a large amount of inorganic materials and third components are added, which further reduces the fatigue resistance of the material.

[0004] In summary, the current protective material has the following problems in the research process: 1. It is difficult to improve the external force sensitivity and energy absorption efficiency. The realization of material intelligent protection mainly depends on the ability of the material to change its strength in normal and stressed states, and the absorption efficiency of impact energy. In the existing system, porous foam materials and damping materials have good energy absorption efficiency, but these materials do not have intelligent response characteristics to external force. Some materials with a certain degree of external force sensitivity mainly transmit the energy generated by external force when they are in a hardened state, and the energy absorption efficiency is low. 2. The contradiction between material fatigue resistance, energy absorption efficiency and shape stability. Among the many properties of protective materials, high external force sensitivity requires the material to have a dynamic cross-linking state, so the mechanical strength of the material is relatively low, and the ability to maintain its shape is weak. The improvement of material energy absorption efficiency requires the material to have obvious viscous characteristics, which also makes the material strength lower and the forming property worse. For most protective materials, damage caused by impact is difficult to repair, so the material has poor fatigue resistance. Using dynamic cross-linking structure or self-adhesion of rubber material can achieve self-repair of material damage under external force impact, thereby improving the fatigue resistance of the material. However, it also causes poor material forming property, which cannot be used freely as a bulk material.

[0005] Therefore, it is urgent to prepare a three-dimensional anti-impact protective material with high yield, intelligent response to external force, high energy absorption efficiency, good material fatigue resistance, and shape stability. SUMMARY

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a three-dimensional anti-impact protective material with high yield, intelligent response to external force, high energy absorption efficiency, good material fatigue resistance, and shape stability, and a preparation method thereof.

[0007] To achieve the above-mentioned purpose and other related purposes, the present application provides a three-dimensional anti-impact protective material, which is characterized by being prepared from raw materials containing the following components by weight:

[0008]

[0009]

[0010] The double-continuous IPN composite material is a reticular polymer constructed by mixing and heating at 60℃ for 2-3h, using IHP material containing silicon and boron as the first continuous phase, and one or more of polysiloxane, branched MQ resin or thermoplastic elastomer as the second continuous phase.

[0011] More preferably, the three-dimensional impact protection material is characterized in that it is prepared from raw materials comprising the following components by weight:

[0012]

[0013] The bicontinuous IPN composite material is a reticular polymer constructed by mixing and reacting the silicon-boron-containing IHP material as the first continuous phase and one or more of polysiloxane, branched MQ resin or thermoplastic elastomer as the second continuous phase at 60°C for 2-3h.

[0014] Preferably, the structure of the IHP material is shown in formula (I):

[0015]

[0016] wherein m is 10-100 and n is 10-100.

[0017] Preferably, the vulcanizing agent is BIBP, the coupling agent is KH-570, and the foaming agent is AC3000h.

[0018] The application also provides a preparation method of the three-dimensional impact protection material, which is characterized by comprising the following steps:

[0019] Step 1, preparing the IHP material:

[0020] (1) reacting polysiloxane and boron-containing crosslinking agent at 50-90°C for 3-6h to obtain a crosslinked product; the mass ratio of the polysiloxane to the boron-containing crosslinking agent is 10-100:1;

[0021] (2) mixing the crosslinked product with a chain extender and reacting at 60-90°C for 2-6h to obtain an IHP material precursor with a network structure; the mass ratio of the polysiloxane to the chain extender is 20-100:1;

[0022] (3) heat treating and / or mechanically treating the IHP material precursor to finally prepare the IHP material with external force sensitivity and self-repairing properties;

[0023] Step 2, constructing the bicontinuous IPN composite material: taking the IHP material as the first continuous phase and one or more of polysiloxane, branched MQ resin or thermoplastic elastomer as the second continuous phase, mixing and heating at 60°C for 2-3h to construct the bicontinuous IPN composite material;

[0024] Step 3, preparation of three-dimensional impact protection material: taking IHP material and / or double continuous IPN composite as the main body, taking EVA foaming material as the carrier, dispersing IHP material and / or double continuous IPN composite in EVA by blending and foaming to obtain three-dimensional impact protection material; wherein the mass ratio of the dispersion main body to the EVA foaming material is 5-30:60-110.

[0025] Preferably, in step 1(1), the polysiloxane is one or more of bis-hydroxyl terminated polydimethylsiloxane, bis-amino terminated polydimethylsiloxane, vinyl end hydroxyl terminated polydimethylsiloxane, vinyl end amino polydimethylsiloxane, hydrogen end hydroxyl polydimethylsiloxane, hydrogen end amino polydimethylsiloxane and vinyl end hydrogen polydimethylsiloxane.

[0026] More preferably, in step 1(1), the polysiloxane is bis-hydroxyl terminated polydimethylsiloxane with a weight average molecular weight of 1000-20000 and a viscosity of 50-100 cps.

[0027] Preferably, in step 1(1), the boron-containing crosslinking agent is one or more of borate, boric acid compound, boric acid ester and trimethoxy boroxine.

[0028] More preferably, in step (1), the boron-containing crosslinking agent is trimethoxy boroxine as shown in (II).

[0029] Preferably, in step (1), the mass ratio of the bis-hydroxyl terminated polydimethylsiloxane to the trimethoxy boroxine is 10-100:1.

[0030] More preferably, in step (1), the mass ratio of the bis-hydroxyl terminated polydimethylsiloxane to the trimethoxy boroxine is 40:1.

[0031] Preferably, the chain extender is diisocyanate or polyisocyanate.

[0032] More preferably, the chain extender is diisocyanate as shown in formula (VI).

[0033] Preferably, in step (1), the mass ratio of the bis-hydroxyl terminated polydimethylsiloxane to the diisocyanate in step (2) is 5-10:0.1-0.25.

[0034] More preferably, in step (1), the mass ratio of the bis-hydroxyl terminated polydimethylsiloxane to the chain extender in step (2) is 5:0.2.

[0035] Since trimethoxy boron oxide hexacyclic ring is a compound which is easy to decompose in water and sensitive to air, it is self-decomposed into methyl alcohol and trimethyl borate shown in formula (III) in the reaction. Trimethyl borate reacts with dihydroxyl terminated polydimethylsiloxane shown in formula (IV) at a temperature below 90℃ for 3-6 hours to obtain cross-linking product shown in formula (V). The whole reaction process is carried out at a temperature not higher than 90℃ without adding catalyst. The side reaction of boronic acid converted into pyroboric acid and metaboric acid caused by high temperature can be completely avoided, and the by-products can be reduced or avoided. At the same time, due to the high reactivity of isocyanate, the product can have high molecular weight.

[0036] Preferably, in step (3), titanium acid tetraisopropyl shown in formula (VIII) is used as hydrolysis modifier to modify IHP material precursor shown in formula (VII); the mass ratio of dihydroxyl terminated polydimethylsiloxane in step (1) to titanium acid tetraisopropyl in step (3) is 5-10:0.1-0.5.

[0037] More preferably, the mass ratio of dihydroxyl terminated polydimethylsiloxane in step (1) to titanium acid tetraisopropyl in step (3) is 200:1.

[0038] Preferably, the second continuous phase is polysiloxane with weight average molecular weight of 2000-10000.

[0039] Preferably, in step 2, the mass ratio of the first continuous phase to the second continuous phase is 1:0.5-1.

[0040] More preferably, in step 2, the mass ratio of the first continuous phase to the second continuous phase is 1:0.5-0.8.

[0041] More preferably, in step 2, the mass ratio of the first continuous phase to the second continuous phase is 1:0.6.

[0042] In step 3 of the present application, three-dimensional impact protection material is prepared by the following method, which comprises:

[0043] 5-30 parts of the double continuous IPN composite, 60-110 parts of EVA resin, 5-30 parts of polyurethane black and white material, 0.5-5 parts of vulcanizing agent, 5-30 parts of coupling agent and 0.5-2 parts of foaming agent are weighed by weight parts and subjected to mixing and blending in a mixer to prepare EVA / IHP blended material; the mixing or double screw extrusion temperature is 90-120℃.

[0044] The EVA / IHP blended material is subjected to mold foaming to prepare three-dimensional impact protection foam material; the mold pressure is 18MPa; and the mold time is 6-15min.

[0045] Preferably, the EVA resin is ethylene-vinyl acetate copolymer, the content of vinyl acetate in the EVA resin is 15-22%, and the molecular weight is 30000-80000.

[0046] Preferably, the mass ratio of the bicontinuous IPN composite to the EVA resin is 10-35:90-110.

[0047] More preferably, the mass ratio of the bicontinuous IPN composite to the EVA resin is 25:100.

[0048] Preferably, the mass ratio of the polyurethane black and white material to the EVA resin is 10-15:90-100.

[0049] More preferably, the mass ratio of the polyurethane black and white material to the EVA resin is 10:100.

[0050] Preferably, the EVA / IHP blend material in step 3 is prepared by mixing 25 parts of bicontinuous INP composite, 100 parts of EVA resin (ethylene-vinyl acetate copolymer, the content of vinyl acetate is 15-22%, and the molecular weight is 30000-80000), 10 parts of polyurethane black and white material, 1 part of vulcanizing agent, 6 parts of coupling agent, and 0.8 parts of foaming agent by weight, and then mixing and blending by banburying or double screw extrusion at a temperature of 90-120℃.

[0051] The application also provides an application of the three-dimensional impact protection material or the three-dimensional impact protection material prepared by the preparation method of the three-dimensional impact protection material in sports protection materials. The application includes being used as a lining of a helmet and / or a lining of a sports protection article such as a knee pad, an elbow pad, a yoga mat, etc., or being used together with a fabric to form a sports protection textile, etc.

[0052] The application has the following beneficial effects:

[0053] 1. The whole reaction process of the three-dimensional impact protection material prepared by the application is carried out at a temperature not higher than 90℃, and no catalyst is needed. The side reaction of conversion of boric acid into pyroboric acid and metaboric acid caused by high temperature can be completely avoided, and the by-products can be reduced or avoided. At the same time, due to the high reactivity of isocyanate, the product can have a high molecular weight.

[0054] 2. The application constructs a new impact-hardened polymer (IHP material) on the basis of the characteristics of STF technology and rising flow material technology. The material has excellent impact-hardening properties and self-repairing properties, and shows good development prospects.

[0055] 3. The double-continuous IPN composite material prepared by using the IHP material as the main body, the composite material is kept in the environment of low temperature -23℃±2℃ and high temperature +50℃±5℃ for 4 hours, the impact force value is 3J, and the sensing impact force is less than or equal to 6KN; the composite material is kept in the environment of normal temperature 23℃±2℃ and low temperature -50℃±2℃ for 4 hours, and then is taken out and folded 10000 times up and down, and no delamination, deformation, bulging, fracture and damage phenomenon appears on the appearance, the positive synergistic regulation mechanism of the two continuous phases is realized, the high external force sensitivity and self-repairing ability of the material are ensured, and the shape maintaining ability of the material is improved;

[0056] 4. The three-dimensional impact protection material prepared by using the double-continuous IPN composite material, the forming property is good, the impact test transmission force value is less than or equal to 35kN (the impact energy is 50J), and the damage caused by the impact can be quickly and actively repaired, the common improvement of the external force sensitivity and the energy absorption efficiency is realized, the contradiction between the material fatigue resistance, the energy absorption efficiency and the shape stability is solved, and the three-dimensional impact protection material is prepared. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 The synthesis route diagram of the IHP material prepared in Example 1 is shown.

[0058] Figure 2 The SEM diagram of the IHP material prepared in Example 1 is shown.

[0059] Figure 3 The rheological spectrum diagram of the IHP material prepared in Example 1 is shown.

[0060] Figure 4 The SEM diagram of the double-continuous IPN composite material prepared in Example 11 is shown.

[0061] Figure 5 The XRD spectrum diagram of the double-continuous IPN composite material prepared in Example 11 is shown.

[0062] Figure 6 One of the SEM diagrams of the three-dimensional impact protection material prepared in Example 16 is shown.

[0063] Figure 7 The second SEM diagram of the three-dimensional impact protection material prepared in Example 16 is shown.

[0064] Figure 8 The impact performance of the impact protection foam material prepared in Example 18 is shown. DETAILED DESCRIPTION

[0065] Following, the embodiments of the present application are illustrated by specific examples, and other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure of the present specification. The present application can also be implemented or applied by other different specific embodiments, and various modifications or changes can be made to the details in the present specification based on different views and applications without departing from the spirit of the present application.

[0066] It should be noted that the process equipment or device not specifically mentioned in the following examples is the conventional equipment or device in the art.

[0067] In addition, it should be understood that the one or more method steps mentioned in the present application do not exclude that there can be other method steps before and after the combination steps or other method steps can be inserted between the explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between the one or more devices / apparatuses mentioned in the present application does not exclude that there can be other devices / apparatuses before and after the combination devices / apparatuses or other devices / apparatuses can be inserted between the two explicitly mentioned devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool to identify each method step, and is not intended to limit the arrangement order of each method step or to limit the scope of the present application, and the change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the scope of the present application.

[0068] In the following examples of the present application, the main test standards and equipment information are as follows: reference standard GA420-2021 "Police Anti-riot Suit", impact protection performance test; equipment: drop hammer impact testing machine, reference standard GA420-2021 "Police Anti-riot Suit", impact energy absorption performance test (energy absorption mode and absorption rate test); equipment: drop hammer impact testing machine.

[0069] Example 1: Preparation of IHP material:

[0070] (1) 100 g of dihydroxyl-terminated polydimethylsiloxane (weight average molecular weight 2000, 25℃ kinematic viscosity 52 cps) was mixed with 2.5 g of trimethoxy boroxin hexacyclic ring, and stirred at 60℃ for 3h to obtain a crosslinked product as shown in (V);

[0071] (2) 4 g of diisocyanate was added to the obtained crosslinked product, and the mixture was reacted at 60℃ for 2h to obtain an IHP material precursor with network structure;

[0072] (3) In the IHP material precursor described above, 0.5 g of titanium acid tetraisopropyl ester is added, and the IHP material precursor is modified at 60°C for 2 h, and then the product is subjected to heat treatment (such as heat compression, heat stretching, heat quenching, heat annealing, and heat aging) and mechanical treatment (such as rolling and molding), to obtain the IHP material.

[0073] The heat treatment and mechanical treatment are widely used at present, and other structures and principles are the same as those of the prior art, and thus will not be described here.

[0074] The IHP material prepared in this example is subjected to the following characterization and testing:

[0075] (1) Morphology characterization:

[0076] SEM characterization is performed on a scanning electron microscope, and the sample preparation method used is as follows: the IHP sample is fixed on a silicon wafer, gold spraying is performed, and then the characterization is performed on a Philips XL 30ESEM electron microscope (Netherlands).

[0077] The SEM of the IHP material prepared in Example 1 is shown in Figure 2 .

[0078] (2) Performance testing:

[0079] The stress sensitivity of the IHP material is characterized by rheology, and the impact protection performance and energy absorption efficiency of the IHP material are characterized by an impact energy tester.

[0080] External force sensitivity definition: the ability of the material to change in hardness under mechanical impact is the impact hardening value σ,

[0081] σ = G'max / G'min;

[0082] wherein G'max is the maximum value of the storage modulus in the rheological test results, and G'min is the minimum value of the storage modulus in the rheological test results;

[0083] Energy absorption efficiency: in the test process, a hammer head with a weight of 5 kg is released vertically to hit the sample placed on the bottom impact force sensor by free fall motion at a specified height h, and the impact speed at the moment of contact with the sample is determined by the falling height h:

[0084] v 2 = 2gh;

[0085] For the blank control group, the force value recorded by the sensor after impact is recorded as F0 (unit: N). For the sample, the force value recorded by the sensor after impact is recorded as F1 (unit: N). The energy absorption efficiency η in the impact process expressed by the impact force can be calculated by the following formula:

[0086]

[0087] Example 2

[0088] Example 2 differs from Example 1 in that the molecular weight of the dihydroxyl terminated polydimethylsiloxane is different, the molecular weight is 5000, the kinematic viscosity at 25°C is 82 cps, and the rest of the process is exactly the same.

[0089] Example 3

[0090] Example 3 differs from Example 1 in that the kinematic viscosity at 25°C of the dihydroxyl terminated polydimethylsiloxane is different, the kinematic viscosity at 25°C is 200 cps, and the rest of the process is exactly the same.

[0091] Example 4

[0092] Example 4 differs from Example 1 in that the mass ratio of dihydroxyl terminated polydimethylsiloxane to boroxin is 100:3, and the rest of the process is exactly the same.

[0093] Example 5

[0094] Example 5 differs from Example 1 in that the mass ratio of dihydroxyl terminated polydimethylsiloxane to boroxin is 100:10, and the rest of the process is exactly the same.

[0095] Example 6

[0096] Example 5 differs from Example 1 in that the mass ratio of dihydroxyl terminated polydimethylsiloxane to boroxin is 100:1, and the rest of the process is exactly the same.

[0097] Example 7

[0098] Example 5 differs from Example 1 in that the mass ratio of dihydroxyl terminated polydimethylsiloxane to boroxin is 80:1, and the rest of the process is exactly the same.

[0099] Example 8

[0100] Example 8 differs from Example 1 in that the mass ratio of dihydroxyl terminated polydimethylsiloxane to diisocyanate is 100:1, and the rest of the process is exactly the same.

[0101] Example 9

[0102] Example 9 differs from Example 1 in that the mass ratio of dihydroxyl terminated polydimethylsiloxane to diisocyanate is 20:1, and the rest of the process is exactly the same.

[0103] Example 10

[0104] Example 10 is different from Example 1 in that the reaction temperature in step (1) is different, the reaction temperature is 80℃, and the rest of the process is exactly the same.

[0105] Comparative Example 1

[0106] Comparative Example 1 is different from Example 1 in that the reaction raw material is different, using a diamino-terminated polydimethylsiloxane instead of a dihydroxy-terminated polydimethylsiloxane, and the rest of the process is exactly the same.

[0107] Comparative Example 2

[0108] Comparative Example 2 is different from Example 1 in that the boron-containing crosslinking agent is different, using boric acid instead of trimethoxy boroxine, and the rest of the process is exactly the same.

[0109] The test method and results of the IHP materials prepared in Examples 2-10 are comparable to those of Example 1, and will not be repeated here.

[0110] The IHP materials prepared in Examples 1-10 and the materials prepared in Comparative Examples 1-2 were subjected to performance testing, and the structure parameters of the IHP materials were characterized by SEM; the external stress resistance and self-healing ability of the IHP materials were characterized by rheology and DMTA; the impact protection performance, energy absorption efficiency and mode of the IHP materials were characterized by an impact energy tester, and the test results are shown in Table 1.

[0111] Table 1 Test results of impact protection performance, energy absorption efficiency and mode of IHP materials

[0112]

[0113] As can be seen from Table 1, the molecular weight and 25℃ kinematic viscosity of dihydroxy-terminated polydimethylsiloxane have the greatest impact on the performance of the product, as the molecular weight of polydimethylsiloxane decreases, the external force sensitivity and energy absorption efficiency of the prepared IHP material are simultaneously improved, and in particular, the prepared material has good energy absorption efficiency while also having intelligent response characteristics to external forces, among which the dihydroxy-terminated polydimethylsiloxane obtained from Example 1 has a molecular weight of 2000 and a 25℃ kinematic viscosity of 52cst, the prepared IHP material has the best performance.

[0114] As shown by the data in Table 1, changing the ratio of dihydroxy-terminated polydimethylsiloxane to trimethoxy boroxine also has a greater impact on the performance of the product, as the ratio of the two increases, the impact resistance of the material improves to a certain extent, and when the ratio is 100:2.5, the maximum improvement effect is achieved, about 93.5.

[0115] Example 11 constructs a double-continuous IPN composite material:

[0116] Take 50 g of the sample of Example 1 as the first continuous phase, and take 30 g of polysiloxane (molecular weight 20000) as the second continuous phase, mix and react at 60°C for 2-3 h to form a double continuous IPN composite system.

[0117] The double continuous IPN composite system prepared in this example was characterized and tested as follows:

[0118] The double continuous IPN composite system was tested in the same way as the IHP material in Example 1.

[0119] Example 12

[0120] Example 12 is different from Example 11 in that the second continuous phase is a hydroxyl MQ resin with a molecular weight of 20000, and the rest of the process is exactly the same.

[0121] Example 13

[0122] Example 13 is different from Example 11 in that the mass ratio of the first continuous phase to the second continuous phase is different, and the mass ratio of the first continuous phase to the second continuous phase is 1:1, and the rest of the process is exactly the same.

[0123] Example 14

[0124] Example 14 is different from Example 11 in that the mass ratio of the first continuous phase to the second continuous phase is different, and the mass ratio of the first continuous phase to the second continuous phase is 1:0.5, and the rest of the process is exactly the same.

[0125] Example 15

[0126] Example 15 is different from Example 11 in that the reaction conditions are different, and the reaction temperature is 80°C, and the rest of the process is exactly the same.

[0127] Comparative Example 3

[0128] Comparative Example 3 is different from Example 11 in that the first continuous phase is different, and the sample of Example 2 is used as the first continuous phase, and the rest of the process is exactly the same.

[0129] The characterization methods and results of the double continuous IPN composite systems prepared in Examples 12-14 are comparable to those of Example 11, and will not be repeated here.

[0130] The performance of the IHP materials and double continuous IPN composite systems prepared in Examples 11-14 and the materials prepared in Comparative Examples 3-5 were tested, the structural parameters of the double continuous IPN composite systems were characterized by SEM, the external stress resistance and self-healing ability of the IHP materials were characterized by rheology and DMTA, and the impact protection performance, energy absorption efficiency and mode of the IHP materials were characterized by an impact energy tester, and the test results are shown in Table 2.

[0131] Table 2 Impact protection performance, energy absorption efficiency and mode detection results of IHP materials

[0132]

[0133] As can be seen from Table 2, the molecular weight of the IHP material and the mass ratio of the first continuous phase to the second continuous phase have the greatest influence on the performance of the product. With the increase of the molecular weight of the IHP material, the external force sensitivity and the energy absorption efficiency of the prepared double-continuous IPN composite system are improved at the same time, especially the prepared material has good energy absorption efficiency and at the same time has the intelligent response characteristics to external force, wherein the double-continuous IPN composite system prepared from the IHP material in Example 11 has the best performance. Moreover, the double-continuous IPN composite system prepared in the present application has excellent intelligent protection performance, and the impact test transmits a force value of ≤35 kN (impact energy is 50 J); the double-continuous IPN composite system is kept in the environment of low temperature -23℃±2℃ and high temperature +50℃±5℃ for 4 hours, and the impact force value is 3 J, the sensing impact force should be ≤6 KN, and the test method adopts GB / T 2812-2006B standard; the double-continuous IPN composite system is kept in the environment of normal temperature 23℃±2℃ and low temperature -50°±2° for 4 hours, and then is taken out and cycled up and down for 10000 times, and no delamination, deformation, bulging, fracture or damage phenomenon is observed on the appearance.

[0134] Example 16 Preparation of a three-dimensional impact protection material:

[0135] 10 g of the double-continuous IPN composite material prepared in Example 11, 100 g of EVA resin, 10 g of polyurethane black and white material, 1 g of vulcanizing agent, 6 g of coupling agent and 0.8 g of foaming agent are weighed, and are co-mixed and blended under the condition of 90℃ to prepare an EVA / IHP blended material;

[0136] The above blended material is molded and foamed under the condition of 18 MPa for 8 min to prepare a three-dimensional impact protection foam material for sports protection.

[0137] Sample impact protection performance test: the test of the impact protection performance of the protection material is performed according to the European standard BS EN1621-1:2012, and the lower the transmitted force value represents the better the protection performance of the material. Test equipment: falling weight impact testing machine

[0138] Impact energy absorption efficiency calculation method: the energy absorption efficiency % of the material under different impact heights = (theoretical impact energy under the height-the impact energy transmitted to the lower sensor) / theoretical impact energy under the height; test equipment: falling weight impact testing machine

[0139] Example 17

[0140] Example 17 differs from Example 16 in that the mass ratio of the bicontinuous IPN composite material to the EVA foaming material is different, the mass ratio is 20:100, and the rest of the process is exactly the same.

[0141] Example 18

[0142] Example 18 differs from Example 16 in that the mass ratio of the bicontinuous IPN composite material (Example 16) to the EVA foaming material is different, the mass ratio is 25:100, and the rest of the process is exactly the same.

[0143] Example 19

[0144] Example 19 differs from Example 16 in that the formula of the foaming material is different, the foaming material is prepared according to the formula comprising 10 g of the bicontinuous IPN composite material, 100 g of EVA resin, 25 g of polyurethane black and white material, 1.5 g of vulcanizing agent, 8 g of coupling agent, 0.6 g of foaming agent, and the rest of the process is exactly the same.

[0145] Example 20

[0146] Example 20 differs from Example 16 in that the IHP material is used instead of the bicontinuous IPN composite material, and the rest of the process is exactly the same.

[0147] Comparative Example 4

[0148] Comparative Example 4 differs from Example 16 in that no IHP material and bicontinuous IPN composite material are added, and the rest of the process is exactly the same.

[0149] The three-dimensional impact protection materials prepared in Examples 16-20 and the material of Comparative Example 4 are tested for performance, and the test results are shown in Table 3 below:

[0150] Table 3

[0151]

[0152]

[0153] As can be seen from Table 3, the ratio of IHP material or double-continuous IPN composite material to EVA foaming material has the greatest influence on the performance of the product, and as the proportion of IHP material or double-continuous IPN composite material increases, the external force sensitivity and impact protection performance of the prepared three-dimensional impact protection material also increase, and the three-dimensional impact protection material prepared from Example 18 has the best performance, reaching the first-class standard of the European Union safety protection. The three-dimensional impact protection material prepared in the application can be applied as a sports protection material, including as a lining of a helmet and / or a sports protection article such as a knee pad, an elbow pad, a yoga mat, a sports fabric, etc., and can also be made into a sports protection textile. The tear strength of the product is ≥15 N; the flame retardant performance: after ten seconds of flame retardant measurement using a Bunsen burner perpendicular to the blue flame, the flame can be extinguished after 5 seconds, and the flame retardant level reaches FV-0 level.

[0154] In summary, the IHP material and double-continuous IPN composite material are prepared by using hydroxyl-terminated polydimethylsiloxane and trimethoxy boroxin as main raw materials, diisocyanate as a chemical linking point, and titanium acid tetraisopropyl ester as a hydrolysis modifier, a three-dimensional composite protection material is constructed, and the three-dimensional composite protection material is applied to a fabric for sports protection. The results show that: the synthesized IHP material and double-continuous IPN composite material have excellent self-repairing ability in addition to the aforementioned excellent external force sensitivity and negative Poisson's ratio. In 20 cycles of testing, the mechanical performance attenuation of the material is less than 30%, and the external force sensitivity shows a certain increasing trend, as high as 6000-10000 times. This shows that the IHP material and double-continuous IPN composite material have good self-repairing performance. The impact test results of the three-dimensional composite protection material constructed by using the IHP material and double-continuous IPN composite material show that: the impact performance of the three-dimensional composite protection material increases significantly with the increase of the external impact speed, and the energy absorption efficiency can reach about 78%, which is significantly better than the performance of the existing sports protection products.

[0155] The above examples are intended to illustrate the embodiments disclosed in the application and should not be construed as limiting the application. In addition, various modifications listed herein and changes in the method and composition of the application will be apparent to those skilled in the art without departing from the scope and spirit of the application. Although the application has been specifically described in conjunction with various preferred embodiments thereof, it will be understood that the application should not be limited to these specific embodiments. In fact, various modifications as described above to obtain the application will be apparent to those skilled in the art.

Claims

1. A three-dimensional impact protection material, characterized in that, The IHP material is prepared from raw materials comprising the following components by weight: The bicontinuous IPN composite is prepared by the following method: Step 1, preparation of IHP material: (1) reacting polysiloxane and boron-containing crosslinking agent at 50-90°C for 3-6h to obtain a crosslinking product; the mass ratio of the polysiloxane to the boron-containing crosslinking agent is 10-100:1; the polysiloxane is bis-hydroxyl terminated polydimethylsiloxane; the boron-containing crosslinking agent is trimethoxy boron oxide hexacyclic ring; (2) mixing the crosslinking product with a chain extender and reacting at 60-9°C for 2-6h to obtain an IHP material precursor with network structure; the ratio of the polysiloxane to the chain extender is 20-100:1; the chain extender is diisocyanate or polyisocyanate; (3) modifying the IHP material precursor with titanium tetraisopropylate as a hydrolysis modifier to prepare the IHP material; Step 2, preparation of bicontinuous IPN composite: mixing IHP material as the first continuous phase and polysiloxane as the second continuous phase at 60°C for 2-3h to prepare the bicontinuous IPN composite; the mass ratio of the first continuous phase to the second continuous phase is 1:0.2-5.

2. A three-dimensional impact protection material according to claim 1, characterized in that The IHP material is prepared from raw materials comprising the following components by weight:

3. A three-dimensional impact protection material according to claim 1, characterized in that The structure of the IHP material is shown in formula (I):

4. The three-dimensional impact protection material according to claim 1, wherein: The vulcanizing agent is BIBP; the coupling agent is KH-570; and the foaming agent is AC3000h.

5. A method of producing a three-dimensional impact protection material as claimed in any one of claims 1 to 4, characterized in that The method comprises the following steps: Step 1, preparation of IHP material: (1) reacting polysiloxane and boron-containing crosslinking agent at 50-90°C for 3-6h to obtain a crosslinking product; the mass ratio of the polysiloxane to the boron-containing crosslinking agent is 10-100:1; (2) mixing the crosslinking product with a chain extender and reacting at 60-9°C for 2-6h to obtain an IHP material precursor with network structure; the ratio of the polysiloxane to the chain extender is 20-100:1; (3) modifying the IHP material precursor with titanium tetraisopropylate as a hydrolysis modifier to prepare the IHP material; Step 2, preparation of bicontinuous IPN composite: mixing IHP material as the first continuous phase and polysiloxane as the second continuous phase at 60°C for 2-3h to prepare the bicontinuous IPN composite; the mass ratio of the first continuous phase to the second continuous phase is 1:0.2-5. Step 3, preparation of three-dimensional impact protection material: mixing IHP material and / or bicontinuous IPN composite as a dispersion main body and EVA resin as a carrier by dense mixing to prepare EVA / IHP blended material, and then forming the EVA / IHP blended material into three-dimensional impact protection material by foaming molding; the mass ratio of the dispersion main body to the EVA resin is 5-30:60-110.

6. The method of claim 5, wherein: The bis-hydroxyl terminated polydimethylsiloxane has a weight average molecular weight of 1000-20000 and a viscosity of 20-200cps.

7. Use of a three-dimensional impact protection material according to any one of claims 1 to 4 or of a three-dimensional impact protection material prepared by the method according to claim 5 for sports protection materials.

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