Preparation method and application of a skin-core structured hydraulic organic-inorganic composite material

Abstract

The present invention discloses a preparation method and application of a water-hardening organic-inorganic composite material with a skin-core structure. The composite material is prepared by dissolving an organic polymer material in a non-aqueous solvent to obtain an organic polymer solution, and then dispersing inorganic particles into part of the organic polymer solution to obtain a blended solution, and then using part of the organic polymer solution as a skin solution or a core solution, and using the blended solution as the corresponding core solution or skin solution, to obtain a two-phase flow with a skin and a core layer through a coaxial spinning technology, and then placing the two-phase flow in a non-aqueous coagulation bath for simultaneous regeneration to obtain a gel with a skin-core structure, and finally drying the gel to obtain a water-hardening organic-inorganic composite material with a skin-core structure. The entire reaction is carried out in a non-aqueous system, and the prepared water-hardening organic-inorganic composite material with a skin-core structure has the characteristics of strong plasticity in short-term water contact and stable mechanical properties in long-term water contact.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of functional composite materials, and in particular relates to a preparation method and application of an organic-inorganic composite material with a skin-core structure and water-hardening properties. Background Art

[0002] Portland cement is the basic raw material for many buildings and structures, initial concrete and reinforced concrete, and is a typical high-strength inorganic material. At present, cement, which has been improved many times, is widely used in construction and related fields. However, it is worth noting that in the process of developing cement-based materials, the plasticity of the material during its hardening process has been ignored. The elongation, toughness (pseudo-toughness), flexural and tensile strength of ultra-high-strength cement materials are poor, which also limits the application of cement in buildings, artworks and other fields that require local details.

[0003] At present, researchers are gradually using cellulose fibers to replace some asbestos fibers for reinforcement. However, compared with asbestos cement products, cellulose-reinforced cement products are more susceptible to damage by water. Moreover, the preparation methods of cellulose-cement composite materials used in the prior art are mostly conventional water blend curing methods, which have low toughness and plasticity and great application limitations.

[0004] The researchers in this case have previously proposed some technologies to solve the above problems, such as Patent Document 1, which can prepare water-hardening organic-inorganic composite materials based on organic polymers and inorganic particles. In this composite material, organic and inorganic substances are interconnected network structures, and have the characteristics of softening in water in a short time and hardening in water in a long time. However, this technology still has certain defects, such as the poor mechanical properties and elongation properties of the obtained dry fiber, and the composite material is easily damaged during the application process, which cannot support the specific application of the composite material.

[0005] Patent document 1: Publication No. CN113831067A.

[0006] In response to this problem, the researchers in this case proposed further improvement plans. Summary of the invention

[0007] In order to overcome the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a preparation method and application of a skin-core structured hydraulic organic-inorganic composite material. The skin layer of the material is a hydrophilic organic substance, and the core layer is a blend of a hydrophilic organic substance and a water-hardening inorganic substance; or the skin layer is a blend of a hydrophilic organic substance and a water-hardening inorganic substance, and the core layer is a hydrophilic organic substance.

[0008] Compared with the prior art, the hydraulic organic-inorganic composite material with a skin-core structure prepared by the present invention can enhance the mechanical properties (breaking strength) and elongation (breaking elongation) of the original composite material.

[0009] This material has an obvious super-superposition effect of performance, which enables the reinforcing role of hydrophilic organic matter to be fully exerted, thereby improving the elongation and toughness (pseudo-toughness), and improving the flexural and tensile properties. It also has strong plasticity when exposed to water for a short time, and the material can be knotted, bent and folded. The mechanical properties are stable when exposed to water for a long time, and the shape of the material is not easily changed by applying external force. Therefore, it has high plasticity and can be widely used in building materials.

[0010] To achieve the above-mentioned object of the invention, the present invention provides a method for preparing a skin-core structured hydraulic organic-inorganic composite material, which comprises at least the following steps:

[0011] 1) dissolving an organic polymer material in a non-aqueous solvent to obtain an organic polymer solution, wherein the content of the organic polymer in the organic polymer solution is 0.5-2 wt %;

[0012] 2) dispersing the inorganic particles into the organic polymer solution obtained in part of step 1) to obtain a blended solution, wherein the mass ratio of the organic polymer to the inorganic particles in the blended solution is 1:1-100;

[0013] 3) using part of the organic polymer solution obtained in step 1) as a skin solution or a core solution, using the blended solution obtained in step 2) as a corresponding core solution or a skin solution, and spinning the skin solution and the core solution through a coaxial spinning technique to obtain a two-phase flow having a skin layer and a core layer;

[0014] 4) regenerating the two-phase flow obtained in step 3) simultaneously in a non-aqueous coagulation bath to obtain a gel having a skin-core structure;

[0015] 5) Drying the gel obtained in step 4) to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0016] As a further improvement of the present invention, in step 1), the organic polymer is an organic polymer containing a hydrophilic group.

[0017] As a further improvement of the present invention, the organic polymer containing a hydrophilic group is a polysaccharide organic polymer or a polypeptide organic polymer.

[0018] As a further improvement of the present invention, the organic polymer containing a hydrophilic group is one or more of cellulose, chitin, chitosan, agar, alginic acid, hyaluronic acid, gelatin, carrageenan, and guar gum.

[0019] As a further improvement of the present invention, the non-aqueous solvent for cellulose is LiCl / DMAc; the non-aqueous solvent for chitin or silk is CaCl2 / methanol, CaCl2 / ethanol, or CaCl2 / formic acid.

[0020] As a further improvement of the present invention, in step 2), the inorganic particles are inorganic particles or powders that harden when exposed to water.

[0021] As a further improvement of the present invention, the water-hardening inorganic particles or powders are one or more of cement, cement clinker, clay or gypsum.

[0022] As a further improvement of the present invention, the non-aqueous coagulation bath is one or more of methanol, ethanol, propanol, DMAc, DMF, acetone, and dichloromethane.

[0023] As a further improvement of the present invention, in step 5), the form of the skin-core structured hydraulic organic-inorganic composite material includes but is not limited to filament, film, block, ring or tube.

[0024] At the same time, the present invention also relates to an application of a skin-core structured hydraulic organic-inorganic composite material prepared by the above-mentioned preparation method, wherein the skin-core structured hydraulic organic-inorganic composite material is soaked in water for 0.1 to 30 minutes to soften it, and then the softened composite material is knotted, bent, folded or woven, and finally soaked in water for 1 to 30 hours to solidify and shape, so as to obtain a high-strength material with a preset shape and organizational structure.

[0025] The beneficial effects of the present invention are:

[0026] 1. Preparation method of the present invention In the coagulation bath, the solvent dissolving the organic polymer in the inner solution and the outer solution gradually diffuses into the coagulation bath, and the material gradually forms a gel-like substance from the outside to the inside through the action of intermolecular hydrogen bonds and the like. In the organic polymer solution, an organic polymer network is formed; in the blended solution, the water-hardening inorganic particles are wrapped in the organic polymer network. During the drying process, the volatile coagulation bath organic matter gradually evaporates, a distinct interface between the polymer layer and the blended layer is formed, and the organic polymer chains and the organic polymer and the inorganic particles are further bonded through hydrogen bonds to form a water-hardening composite material.

[0027] 2. When the hydraulic organic-inorganic composite material prepared by the present invention is immersed in water, the hydraulic inorganic particles will react and harden to generate strength after encountering water, and show an increase in brittleness. The internal polymer network and the external polymer network layer effectively provide toughness to prevent the network formed by the hydraulic inorganic particles from breaking during the material editing process, or promote the re-networking of the broken network. As time goes by, the hydraulic inorganic particles harden and form a network, and the organic and inorganic substances in the composite material are network structures that are interconnected. Therefore, it has the characteristics of strong plasticity when exposed to water for a short time and stable mechanical properties when exposed to water for a long time. Among them, the strong plasticity when exposed to water for a short time is mainly the characteristic of the organic polymer material in the composite material, and the stable mechanical properties when exposed to water for a long time is mainly the characteristic of the inorganic particles in the composite material.

[0028] 3. Since the hydraulic organic-inorganic composite material prepared by the present invention has the characteristics of softening in water for a short time and hardening in water for a long time, it can be softened by soaking in water for a short time and then subjected to various molding processes, such as bending, knotting, weaving, etc., and finally solidified into shape, which significantly improves the plasticity of such composite materials and broadens their application.

[0029] 4. The skin-core structured hydraulic organic-inorganic composite material prepared by the present invention has a double-layer structure of a skin layer and a core layer. When the hydraulic inorganic particles begin to form a network when in contact with water, the polymer layer can provide mechanical support or protection for the formation of the overall network on a macroscopic level, and can effectively extend the editable time when in contact with water for a short period of time. After the hydraulic inorganic particle network is formed, in addition to the double network structure inside the material, the macroscopic polymer layer also provides enhanced mechanical properties for the material.

[0030] 5. When the skin-core structured hydraulic organic-inorganic composite material prepared by the present invention is used in actual applications, compared with the prior art, it can enhance the mechanical properties (fracture strength) and elongation (fracture elongation) on the basis of the original composite material, that is, it can obtain better mechanical properties, and its fracture stress can reach 90.65MPa, and its fracture strain can reach 45.08%. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of the preparation method of the present invention;

[0032] Figure 2 This is a characteristic demonstration diagram of the skin-core structure hydraulic organic-inorganic composite material prepared by the preparation method of the present invention;

[0033] Figure 3 The SEM image of the skin-core structured hydraulic organic-inorganic composite material prepared by the preparation method of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below in conjunction with specific embodiments.

[0035] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the specific embodiments, while other details that are not closely related to the present invention are omitted.

[0036] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0037] The present invention provides a method for preparing a skin-core structured hydraulic organic-inorganic composite material, which comprises at least the following steps:

[0038] 1) dissolving an organic polymer material in a non-aqueous solvent to obtain an organic polymer solution, wherein the content of the organic polymer in the organic polymer solution is 0.5-2 wt %;

[0039] 2) dispersing the inorganic particles into the organic polymer solution obtained in part of step 1) to obtain a blended solution, wherein the mass ratio of the organic polymer to the inorganic particles in the blended solution is 1:1-100;

[0040] 3) using the organic polymer solution obtained in the remaining step 1) as a skin solution or a core solution, using the blended solution obtained in the step 2) as a corresponding core solution or a skin solution, and spinning the skin solution and the core solution through a coaxial spinning technique to obtain a two-phase flow having a skin layer and a core layer;

[0041] 4) regenerating the two-phase flow obtained in step 3) simultaneously in a non-aqueous coagulation bath to obtain a gel having a skin-core structure;

[0042] 5) Drying the gel obtained in step 4) to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0043] By adopting the above technical scheme, the entire preparation method is carried out in a non-aqueous system. The hydrophilic organic polymer and the water-hardening inorganic particles are in a non-aqueous coagulation bath. According to similar compatibility, the non-aqueous good solvent of the organic polymer gradually diffuses into the non-aqueous coagulation bath. The hydrophilic organic polymer gradually forms a gel-like substance from the surface to the inside through the interaction of intermolecular hydrogen bonds and other forces.

[0044] In the organic polymer solution, an organic polymer network is formed; in the blended solution, the hydraulic inorganic particles are wrapped in the organic polymer network.

[0045] During the drying process, the volatile organic matter in the coagulation bath gradually evaporates, and a distinct interface between the polymer layer and the blended layer is formed; moreover, the organic polymer chains and between the organic polymer and the inorganic particles are further combined through hydrogen bonds to form a water-hardening composite material.

[0046] When the composite material is immersed in water, the water-hardening inorganic particles will react with water and harden to generate strength, and show an increase in brittleness. The internal polymer network and the external polymer network layer effectively provide toughness to prevent the network formed by the water-hardening inorganic particles from breaking during the material editing process, or promote the re-networking of the broken network. As time goes by, the water-hardening inorganic particles harden and form a network. The organic and inorganic substances in the composite material are each interconnected network structure.

[0047] Therefore, the skin-core structured hydraulic organic-inorganic composite material prepared as described above of the present invention has the characteristics of strong plasticity when exposed to water for a short time and stable mechanical properties when exposed to water for a long time; among them, the strong plasticity when exposed to water for a short time is mainly the characteristic of the organic polymer material in the composite material, and the stable mechanical properties when exposed to water for a long time are mainly the characteristics of the inorganic particles in the composite material.

[0048] The organic polymer containing the hydrophilic group is one or more of cellulose, chitin, chitosan, agar, alginic acid, hyaluronic acid, gelatin, carrageenan, and guar gum. The selection of natural hydrophilic organic polymers has the advantages of wide sources of raw materials and sustainable development, and the ability to form a good colloid with inorganic minerals such as cement. Through the process of the present invention, a composite material having the characteristics of softening in water in a short time and hardening in water in a long time is obtained.

[0049] It should be noted that, in some embodiments, the organic polymer containing a hydrophilic group is cellulose, and correspondingly, the non-aqueous solvent is LiCl / DMAc (lithium chloride / N,N-dimethylacetamide).

[0050] In some other embodiments, when the organic polymer containing a hydrophilic group is chitosan, the non-aqueous solvent is selected as CaCl 2 / Methanol, CaCl 2 / ethanol, CaCl 2 / Formic acid.

[0051] When the inorganic particles mentioned above are inorganic powders or particles that harden when exposed to water, one or more of cement, cement clinker, clay or gypsum can be selected.

[0052] It should be noted that, in some specific embodiments, when cement is selected for the above-mentioned water-hardening inorganic powders and particles, silicate cement, aluminate water, sulphoaluminate cement, ferroaluminate cement, fluoroaluminate cement, phosphate cement, etc. can be considered; at the same time, inorganic fillers such as calcium oxide, calcium carbonate, silicon dioxide, fly ash, aluminum oxide and iron oxide can also be considered to be added.

[0053] The non-aqueous coagulation bath uses a volatile coagulation bath other than water, such as one or more of methanol, ethanol, propanol, DMAc, DMF, acetone, and dichloromethane.

[0054] It is understandable that, in order to promote the subsequent regeneration of the gel, the non-aqueous coagulation bath here may be a non-aqueous coagulation bath having a certain compatibility with the non-aqueous solvent in step 1).

[0055] In step 3), the skin layer solution and the core layer solution are subjected to coaxial spinning technology to obtain a two-phase flow having a skin layer and a core layer, wherein the coaxial spinning technology may include wet spinning and electrostatic spinning technology.

[0056] The form of the skin-core structure hydraulic organic-inorganic composite material obtained in step 5) includes but is not limited to filaments, films, blocks, rings or tubes, etc. Among them, the filaments can be obtained by extrusion or injection, the films can be obtained by casting, and the blocks, rings or tubes can be obtained by curing and regenerating in corresponding molds.

[0057] At the same time, the present invention also proposes the application of the skin-core structure hydraulic organic-inorganic composite material prepared based on the above preparation method. Specifically, the skin-core structure hydraulic organic-inorganic composite material prepared based on the above preparation method is soaked in water for 0.1 to 30 minutes to soften it, and then the softened composite material is knotted, bent, folded or woven, and finally soaked in water for 1-30 hours to solidify and shape, so as to obtain a high-strength material with a preset shape and organizational structure.

[0058] Since the skin-core structured hydraulic organic-inorganic composite material prepared by the present invention has the characteristics of being softened in water for a short time and hardened in water for a long time, it can be softened by soaking in water for a short time, then formed and processed, and finally cured and formed, which significantly improves the plasticity of such composite material and broadens its application range.

[0059] The present invention will be further described below with reference to specific embodiments:

[0060] The present invention adopts the 5943 universal material testing machine of INSTRON Corporation of the United States. Before the test, the material is balanced for 12 hours under a temperature of 25°C and a humidity of 65%. During the test, the sample stretching speed is 10mm / min and the test length is 20mm, that is, under the pre-tension condition, the length of the fiber sample is 20mm.

[0061] In the accompanying drawings, Figure 2 This is a flow chart of using this method to prepare fibers. The inner layer solution and outer layer solution prepared in advance are connected using a coaxial spinning needle. The inner and outer layers are simultaneously regenerated in an ethanol coagulation bath and collected by a collecting device. After drying, it becomes one of the products prepared by this method.

[0062] Figure 2 Reason Figure 1 The characteristics of the finished product prepared by the process are demonstrated. It has shape stability in the dry state, increased flexibility and toughness after short-term contact with water, and the material is editable. The shape stability increases after long-term contact with water, the mechanical properties are stable, and the material is finalized.

[0063] Figure 3 for Figure 1 The SEM image of the finished product prepared by the process clearly shows the overall and local skin-core structure of the product.

[0064] Example 1

[0065] 1) crushing cellulose wood pulp with a degree of polymerization of 400-800 into fragments with a length of 0.1-0.5 mm and drying them in an oven at 60° C. for 12 hours;

[0066] 2) Weigh 18 g of lithium chloride (LiCl) and 192 g of N,N-dimethylacetamide (DMAc) in a 250 ml sample bottle, mix and dissolve by ultrasonication;

[0067] 3) 3 g of the cellulose wood pulp obtained in step 1) and 297 g of DMAc / LiCl solution were added to a three-necked flask, and heated and stirred for 2.5 h to obtain a transparent cellulose solution with a mass fraction of 1 wt%, wherein the heating temperature was 112° C. and the stirring rate was 550 rpm;

[0068] 4) adding 0.5 g of silicate cement powder to the cellulose solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain a silicate cement / cellulose spinning solution, wherein the mass of the silicate cement powder is 0.5 times the mass of the cellulose;

[0069] 5) Take two syringes, one for extracting the transparent cellulose solution obtained in step 3) as the outer layer solution, and the other for extracting the silicate cement / cellulose spinning solution obtained in step 4) as the inner layer solution;

[0070] 6) The two syringes obtained in step 5) are placed on different push pumps, and the two needle tips are simultaneously connected to the same coaxial needle.

[0071] 7) immersing the coaxial needle in step 6) into an ethanol coagulation bath, and simultaneously starting two push pumps, with the injection speed of the inner solution push pump and the injection speed of the outer solution push pump both being 0.4 mL / min, to obtain a gel having a skin-core structure;

[0072] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0073] Example 2-11

[0074] Compared with Example 1, Example 2-11 is different in that the mass of silicate cement powder in step 4 is changed. Except for the above differences, other operations are the same and will not be repeated here. The specific experimental conditions and measurement results are shown in Table 1; the changes in the mechanical properties of the composite materials in dry and wet states are shown in Table 2 (dry state: the state just prepared; wet state: the state after being put into water).

[0075] Table 1

[0076]

[0077]

[0078] Table 2

[0079]

[0080] It can be seen from Table 1 that with the increase of the silicate cement content in the inner layer solution, the fracture stress of the composite material gradually decreases, and the fracture strain also basically shows a gradually decreasing trend, and only the fracture strain of Example 5 increases.

[0081] In Table 2, a negative change in the fracture stress indicates that the mechanical properties of the composite material decrease and that it is easy to break when subjected to tensile stress; a larger change in the fracture strain indicates that the flexibility and toughness of the material increase after contact with water, and the material has better editability.

[0082] It can be seen from Table 2 that with the increase of the silicate cement content in the inner layer solution, the strength of the composite material gradually increases when it is stretched, but its flexibility and toughness decrease after contact with water, and the editability of the material also decreases.

[0083] Therefore, considering the flexibility and toughness of the composite material after contact with water, portability and mechanical properties in the final form, a mass ratio of silicate cement to cellulose in the inner layer solution between 1-10 can achieve better results.

[0084] Example 12

[0085] 1) crushing cellulose wood pulp with a degree of polymerization of 400-800 into fragments with a length of 0.1-0.5 mm and drying them in an oven at 60° C. for 12 hours;

[0086] 2) Weigh 18 g of lithium chloride (LiCl) and 192 g of N,N-dimethylacetamide (DMAc) in a 250 ml sample bottle, mix and dissolve by ultrasonication;

[0087] 3) Add 4.5 g of the cellulose wood pulp obtained in step 1) and 295.5 g of DMAc / LiCl solution into a three-necked flask, heat and stir for 2.5 h to obtain a transparent cellulose solution with a mass fraction of 1.5 wt%, wherein the heating temperature is 112° C. and the stirring rate is 550 rpm. A transparent cellulose solution with a mass fraction of 1 wt% is prepared by using the above method;

[0088] 4) adding 10 g of silicate cement powder to the 1 wt % cellulose solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain a silicate cement / cellulose spinning solution, wherein the mass of the silicate cement powder is 10 times the mass of the cellulose;

[0089] 5) Take two needles, one to extract the 1.5 wt% transparent cellulose solution obtained in step 3) as the outer layer solution, and the other to extract the silicate cement / cellulose spinning solution obtained in step 4) as the inner layer solution;

[0090] 6) placing the two needle tubes obtained in step 5) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0091] 7) immersing the coaxial needle in step 6) into an ethanol coagulation bath, and simultaneously starting two push pumps at an injection speed of 0.4 mL / min to obtain a gel having a skin-core structure;

[0092] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0093] Example 13

[0094] The difference between Example 13 and Example 12 is that the mass of cellulose wood pulp in step 3 is changed. Except for the above difference, other operations are the same and will not be repeated here. The specific experimental conditions and measurement results are shown in Table 3.

[0095] Table 3

[0096]

[0097] It can be seen from the results of Example 7 and Examples 12 and 13 that the concentration of the outer layer organic solution is positively correlated with the fracture stress and fracture strain of the composite material.

[0098] As the concentration of the outer organic solution increases, more organic macromolecules participate in constructing the organic macromolecular network, and the interaction between molecules becomes stronger, which helps to improve the overall strength and strain of the composite material.

[0099] However, when the concentration of the cellulose solution reaches 2%, the needle will be blocked during the process of preparing the core-skin structure material by coaxial spinning. Since the technical purpose of the present invention is to obtain a composite material with a core-skin structure, the concentration of the cellulose solution should not be too high.

[0100] Embodiment 14

[0101] 1) crushing cellulose wood pulp with a degree of polymerization of 400-800 into fragments with a length of 0.1-0.5 mm and drying them in an oven at 60° C. for 12 hours;

[0102] 2) Weigh 18 g of lithium chloride (LiCl) and 192 g of N,N-dimethylacetamide (DMAc) in a 250 ml sample bottle, mix and dissolve by ultrasonication;

[0103] 3) 3 g of the cellulose wood pulp obtained in step 1) and 297 g of DMAc / LiCl solution were added to a three-necked flask, and heated and stirred for 2.5 h to obtain a transparent cellulose solution with a mass fraction of 1 wt%, wherein the heating temperature was 112° C. and the stirring rate was 550 rpm;

[0104] 4) adding 0.5 g of silicate cement powder to the cellulose solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain a silicate cement / cellulose spinning solution, wherein the mass of the silicate cement powder is 10 times the mass of the cellulose;

[0105] 5) Take two syringes, one for extracting the transparent cellulose solution obtained in step 3) as the outer layer solution, and the other for extracting the silicate cement / cellulose spinning solution obtained in step 4) as the inner layer solution;

[0106] 6) placing the two needle tubes obtained in step 5) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0107] 7) Immerse the coaxial needle in step 6) in an ethanol coagulation bath, and start two push pumps at the same time, with the injection speed of the outer solution push pump being 0.2 mL / min and the injection speed of the inner solution push pump being 0.4 mL / min, to obtain a gel with a skin-core structure;

[0108] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0109] Examples 15-23

[0110] Compared with Example 15, Examples 15-21 differ in that the injection speed of the push pump in step 7 is changed. Except for the above differences, other operations are the same and will not be repeated here. The specific experimental conditions and measurement results are shown in Table 4.

[0111] Table 4

[0112]

[0113]

[0114] By comparing the results of Example 7 with Examples 14-17, it can be seen that increasing the outer layer solution pushing pump speed will reduce the fracture strain of the composite material. The reason for the reduction is that within a certain period of time, the amount of organic solution squeezed out by the needle increases, the regeneration speed of the organic network in the coagulation bath slows down, and the network fails to regenerate completely.

[0115] Among them, the composite material obtained in Example 14 has improved mechanical properties and elongation compared with other examples, and has water-hardening characteristics.

[0116] Comparing the results of Example 7 with Examples 18-21, it can be seen that reducing the inner layer solution pumping speed will increase the fracture strain of the composite material. Within a certain period of time, the amount of inorganic matter extruded by the needle is reduced, and the composite material as a whole is closer to an organic network, and its fracture stress and fracture strain performance are therefore improved.

[0117] By comparing the results of Example 7 with Examples 22-23, it can be seen that the composite material of Example 22 prepared by an inner layer solution containing only silicate cement / cellulose spinning solution cannot obtain the effects of other examples in terms of mechanical properties and elongation; and the material of Example 23 prepared by an outer layer solution containing only cellulose solution has high mechanical strength and elongation, but is not water-hardening, which does not meet the technical usage scenarios expected by the present invention and cannot achieve the performance of Example 2.

[0118] At the same time, by comparing Example 22 with other examples, it can be seen that after the skin-free composite material is introduced with the skin material having excellent performance, the performance of the composite material at various injection flow rates is improved.

[0119] Embodiment 24

[0120] 1) Dry the chitosan powder in an oven at 60°C for 12 hours;

[0121] 2) Weigh 5g of calcium chloride (CaCl 2 ) and 95 g formic acid (FA) were mixed in a 250 ml sample bottle and dissolved by stirring;

[0122] 3) Add 1 g of chitosan powder obtained in step 1) and FA / CaCl into a three-necked flask. 2 99 g of the solution was stirred at room temperature for 1 hour and then stored at low temperature for 1 hour to obtain a transparent chitosan solution with a mass fraction of 1 wt%, wherein the storage temperature was 8°C and the stirring rate was 550 rpm;

[0123] 4) adding 0.5 g of silicate cement powder to the chitosan solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain a silicate cement / chitosan spinning solution, wherein the mass of the silicate cement powder is 0.5 times the mass of the chitosan;

[0124] 5) Take two syringes, one for extracting the transparent chitosan solution obtained in step 3) as the outer layer solution, and the other for extracting the silicate cement / chitosan spinning solution obtained in step 4) as the inner layer solution;

[0125] 6) placing the two needle tubes obtained in step 5) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0126] 7) Immerse the coaxial needle in step 6) in an ethanol coagulation bath, and start two push pumps at the same time, with the injection speed of the outer layer solution and the inner layer solution push pumps both being 0.4 mL / min, to obtain a gel with a skin-core structure;

[0127] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0128] Embodiment 25

[0129] 1) Using 0.5wt% NaCO 3 The solution was used to degummed the silk at a temperature of 100°C for 1.5 h. After degumming, the silk was filtered and dried, and the dried silk was dried in an oven at 80°C for 12 h.

[0130] 2) Weigh 5g of calcium chloride (CaCl 2 ) and 95 g formic acid (FA) were mixed in a 250 ml sample bottle and dissolved by stirring;

[0131] 3) Add 1 g of silk obtained in step 1) and FA / CaCl into a three-necked flask. 2 99 g of the solution was stirred at room temperature for 30 min to obtain a transparent silk solution with a mass fraction of 1 wt% at a stirring rate of 550 rpm;

[0132] 4) adding 0.5 g of silicate cement powder to the chitosan solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain a silicate cement / silk spinning solution, wherein the mass of the silicate cement powder is 0.5 times the mass of the silk;

[0133] 5) Take two syringes, one for extracting the transparent silk solution obtained in step 3) as the outer solution, and the other for extracting the silicate cement / silk spinning solution obtained in step 4) as the inner solution;

[0134] 6) placing the two needle tubes obtained in step 5) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0135] 7) Immerse the coaxial needle in step 6) in an ethanol coagulation bath, and start two push pumps at the same time, with the injection speed of the outer layer solution and the inner layer solution push pumps both being 0.4 mL / min, to obtain a gel with a skin-core structure;

[0136] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0137] Embodiment 26

[0138] 1) Add 1 g of gelatin into 99 g of deionized water to dissolve to obtain a transparent gelatin solution at 65°C for 10 min;

[0139] 2) Adding the gelatin solution with a mass fraction of 1 wt% obtained in step 1) and 0.5 g of silicate cement powder into a three-necked flask, stirring at a rate of 550 rpm, to obtain a silicate cement / gelatin spinning solution, wherein the mass of the silicate cement powder is 0.5 times the mass of the gelatin;

[0140] 3) Take two syringes, one for extracting the transparent gelatin solution obtained in step 1) as the outer layer solution, and the other for extracting the silicate cement / gelatin spinning solution obtained in step 2) as the inner layer solution;

[0141] 4) placing the two needle tubes obtained in step 3) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0142] 5) immersing the coaxial needle in step 4) in a cold water coagulation bath at a temperature of 10° C. and simultaneously starting two push pumps, with the injection speed of the push pumps for the outer and inner layer solutions being 0.4 mL / min, to obtain a gel having a skin-core structure;

[0143] 6) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0144] Embodiment 27

[0145] 1) crushing cellulose wood pulp with a degree of polymerization of 400-800 into fragments with a length of 0.1-0.5 mm and drying them in an oven at 60° C. for 12 hours;

[0146] 2) Weigh 18 g of lithium chloride (LiCl) and 192 g of N,N-dimethylacetamide (DMAc) in a 250 ml sample bottle, mix and dissolve by ultrasonication;

[0147] 3) 3 g of the cellulose pulp obtained in step 1) and 297 g of DMAc / LiCl solution were added to a three-necked flask, and heated and stirred for 2.5 h to obtain a transparent cellulose solution with a mass fraction of 1 wt%, wherein the heating temperature was 112° C. and the stirring rate was 550 rpm;

[0148] 4) adding 0.5 g of silicate cement powder to the cellulose solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain a silicate cement / cellulose spinning solution, wherein the mass of the silicate cement powder is 0.5 times the mass of the cellulose;

[0149] 5) Take two syringes, one for extracting the transparent cellulose solution obtained in step 3) as the outer layer solution, and the other for extracting the silicate cement / cellulose spinning solution obtained in step 4) as the inner layer solution;

[0150] 6) placing the two needle tubes obtained in step 5) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0151] 7) immersing the coaxial needle in step 6) into a water coagulation bath, and simultaneously starting two push pumps at an injection speed of 0.4 mL / min to obtain a gel having a skin-core structure;

[0152] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0153] Embodiment 28

[0154] 1) crushing cellulose wood pulp with a degree of polymerization of 400-800 into fragments with a length of 0.1-0.5 mm and drying them in an oven at 60° C. for 12 hours;

[0155] 2) Weigh 18 g of lithium chloride (LiCl) and 192 g of N,N-dimethylacetamide (DMAc) in a 250 ml sample bottle, mix and dissolve by ultrasonication;

[0156] 3) 3 g of the cellulose pulp obtained in step 1) and 297 g of DMAc / LiCl solution were added to a three-necked flask, and heated and stirred for 2.5 h to obtain a transparent cellulose solution with a mass fraction of 1 wt%, wherein the heating temperature was 112° C. and the stirring rate was 550 rpm;

[0157] 4) adding 0.5 g of aluminate cement powder to the cellulose solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain an aluminate cement / cellulose spinning solution, wherein the mass of the aluminate cement powder is 0.5 times the mass of the cellulose;

[0158] 5) Take two syringes, one for extracting the transparent cellulose solution obtained in step 3) as the outer layer solution, and the other for extracting the aluminate cement / cellulose spinning solution obtained in step 4) as the inner layer solution;

[0159] 6) placing the two needle tubes obtained in step 5) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0160] 7) immersing the coaxial needle in step 6) into an ethanol coagulation bath, and simultaneously starting two push pumps at an injection speed of 0.4 mL / min to obtain a gel having a skin-core structure;

[0161] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0162] Embodiment 29

[0163] 1) crushing cellulose wood pulp with a degree of polymerization of 400-800 into fragments with a length of 0.1-0.5 mm and drying them in an oven at 60° C. for 12 hours;

[0164] 2) Weigh 18 g of lithium chloride (LiCl) and 192 g of N,N-dimethylacetamide (DMAc) in a 250 ml sample bottle, mix and dissolve by ultrasonication;

[0165] 3) 3 g of the cellulose wood pulp obtained in step 1) and 297 g of DMAc / LiCl solution were added to a three-necked flask, and heated and stirred for 2.5 h to obtain a transparent cellulose solution with a mass fraction of 1 wt%, wherein the heating temperature was 112° C. and the stirring rate was 550 rpm;

[0166] 4) adding 0.5 g of sulphoaluminate cement powder to the cellulose solution in step 3), stirring at a rate of 250 rpm, and continuously stirring for 1 min to obtain a sulphoaluminate cement / cellulose spinning solution, wherein the mass of the sulphoaluminate cement powder is 0.5 times the mass of the cellulose;

[0167] 5) Take two syringes, one for extracting the transparent cellulose solution obtained in step 3) as the outer layer solution, and the other for extracting the sulphoaluminate cement / cellulose spinning solution obtained in step 4) as the inner layer solution;

[0168] 6) placing the two needle tubes obtained in step 5) on different push pumps, and connecting the two needle tips to the same coaxial needle head;

[0169] 7) immersing the coaxial needle in step 6) into an ethanol coagulation bath, and simultaneously starting two push pumps at an injection speed of 0.4 mL / min to obtain a gel having a skin-core structure;

[0170] 8) Drying the obtained gel to obtain a skin-core structured hydraulic organic-inorganic composite material.

[0171] The specific experimental conditions and test results are shown in Table 5.

[0172] Table 5

[0173]

[0174] By comparing the results of Example 1 and Examples 24-25, it can be seen that changing the type of organic matter in the composite material will not have a significant impact on the functionality of the composite material.

[0175] By comparing the results of Example 1 and Examples 26-27, it can be seen that changing the type of inorganic substance in the composite material will not affect the functionality of the composite material.

[0176] Based on Examples 1-27, the skin-core structured hydraulic organic-inorganic composite materials prepared by the present method all have the characteristics of strong plasticity when exposed to water for a short time and stable mechanical properties when exposed to water for a long time.

[0177] In summary, the preparation method of the skin-core structure hydraulic organic-inorganic composite material provided by the present invention is to compound the organic polymer with the inorganic substance in a non-aqueous system, so as to obtain a hydraulic organic-inorganic composite material with the characteristics of softening in water in a short time and hardening in water in a long time. By utilizing this characteristic, after being softened by soaking in water for a short time, it can be subjected to various molding processes (such as knotting, bending, folding or weaving), and finally cured and molded, so as to improve the plasticity of such composite materials, broaden their application range, and also obtain better mechanical properties.

[0178] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a skin-core structured hydraulic organic-inorganic composite material, It is characterized in that At least the following steps are included: 1) dissolving an organic polymer material in a non-aqueous solvent to obtain an organic polymer solution, wherein the content of the organic polymer in the organic polymer solution is 0.5-2wt%; 2) dispersing the inorganic particles into the organic polymer solution obtained in part of step 1) to obtain a blended solution, wherein the mass ratio of the organic polymer to the inorganic particles in the blended solution is 1:1-100; 3) using part of the organic polymer solution obtained in step 1) as a skin solution or a core solution, using the blended solution obtained in step 2) as a corresponding core solution or a skin solution, and spinning the skin solution and the core solution through coaxial spinning technology to obtain a two-phase flow having a skin layer and a core layer; 4) regenerating the two-phase flow obtained in step 3) simultaneously in a non-aqueous coagulation bath to obtain a gel having a skin-core structure; 5) drying the gel obtained in step 4) to obtain a skin-core structured hydraulic organic-inorganic composite material; In step 2), the inorganic particles are inorganic particles or powders that harden when exposed to water; The water-hardening inorganic particles or powders are one or more of cement, cement clinker, clay or gypsum.

2. The method for preparing the skin-core structure hydraulic organic-inorganic composite material according to claim 1, It is characterized in that In step 1), the organic polymer is an organic polymer containing a hydrophilic group.

3. The method for preparing the skin-core structured hydraulic organic-inorganic composite material according to claim 2, It is characterized in that The organic polymer containing a hydrophilic group is a polysaccharide organic polymer or a polypeptide organic polymer.

4. The method for preparing the skin-core structure hydraulic organic-inorganic composite material according to claim 3, It is characterized in that The organic polymer containing a hydrophilic group is one or more of cellulose, chitin, chitosan, agar, alginic acid, hyaluronic acid, gelatin, carrageenan, and guar gum.

5. The method for preparing the skin-core structure hydraulic organic-inorganic composite material according to claim 4, It is characterized in that The non-aqueous solvent for cellulose is LiCl / DMAc; the non-aqueous solvent for chitin or silk is CaCl 2 / Methanol, CaCl 2 / ethanol, CaCl 2 / Formic acid.

6. The method for preparing the skin-core structure hydraulic organic-inorganic composite material according to claim 1, It is characterized in that The non-aqueous coagulation bath is one or more of methanol, ethanol, propanol, DMAc, DMF, acetone, and dichloromethane.

7. The method for preparing the skin-core structured hydraulic organic-inorganic composite material according to claim 1, It is characterized in that In step 5), the form of the skin-core structured hydraulic organic-inorganic composite material includes but is not limited to filament, film, block, ring or tube.

8. Use of a skin-core structure hydraulic organic-inorganic composite material prepared by the preparation method according to any one of claims 1 to 7, It is characterized in that The skin-core structure hydraulic organic-inorganic composite material is soaked in water for 0.1-30 minutes to soften it, and then the softened composite material is knotted, bent, folded or woven, and finally soaked in water for 1-30 hours to solidify and shape, so as to obtain a high-strength material with a preset shape and organizational structure.

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