CN113089131B

CN113089131B - Preparation method of inorganic nanoparticle dynamic cross-linking double-network modified natural polymer material

Info

Publication number: CN113089131B
Application number: CN202110372680.XA
Authority: CN
Inventors: 张鸿; 闫铭; 汤松; 周国航; 曾介祥
Original assignee: Dalian Polytechnic University
Current assignee: Dalian Polytechnic University
Priority date: 2021-04-07
Filing date: 2021-04-07
Publication date: 2022-10-04
Anticipated expiration: 2041-04-07
Also published as: CN113089131A

Abstract

The invention provides a preparation method of an inorganic nanoparticle dynamic cross-linking double-network modified natural polymer material. The dynamic cross-linked double-network structure is generated by the synergistic effect of covalent bonds, dynamic hydrogen bonds, ionic cross-linking and interpenetrating interlocking. Active double bonds of inorganic nano particles and monomers are copolymerized into hybrid flexible long chains, natural polymer chains are synchronously introduced by a one-pot method, a natural polymer ion crosslinking network is used as a rigid first network, dynamic hydrogen bond pseudo-crosslinking is used as a flexible second network to form a dynamic crosslinking double-network structure, intermolecular action and rheological behavior are regulated and controlled, and fibers are formed by ionic crosslinking gelation in a coagulant solution. The inorganic nano particle dynamic crosslinking double-network structure has obvious reinforcing and toughening effects, the breaking strength of the fiber reaches 3.68cN/dtex, and the elongation at break reaches 13.65%, so that the fiber can be applied to the fields of textiles, aerospace, sports goods, medical treatment and the like.

Description

Preparation method of inorganic nanoparticle dynamic cross-linking double-network modified natural polymer material

Technical Field

The invention belongs to the field of materials, and particularly relates to an inorganic nanoparticle dynamic cross-linking double-network structure modified natural polymer material and a preparation method thereof.

Background

Currently, the textile industry is developed rapidly and has a good prospect, and the development of textiles at present mainly comprises natural fibers, regenerated fibers, synthetic fibers and the like. The natural polymer fiber is a material prepared from natural macromolecules, has the excellent characteristics of antibiosis, degradability, renewability and the like, and is widely applied to the fields of medical treatment, cosmetology, environmental protection, biochemistry and the like. Its appearance and development bring a new research direction for researchers. However, the pure natural polymer fibers often have defects in mechanical properties, which cannot meet the requirements of people, and restrict further application and development of the pure natural polymer fibers. Therefore, in recent years, many modifications have been made to improve mechanical properties of natural polymer fibers by introducing other components or forming a special structure to broaden the application fields thereof, such as organic components, inorganic components and double network structures.

In recent years, a patent publication has been made on the preparation of a fiber material by using a natural polymer as a substrate, and patent No. CN110359110A uses a regenerated cellulose fiber as a template, and sodium alginate grafted cellulose pulp is prepared by carrying out a grafting reaction between sodium alginate and cellulose pulp under the action of a cross-linking agent; the finally prepared alginate modified regenerated cellulose fiber mainly comprises a regenerated cellulose fiber matrix and alginate uniformly dispersed in the regenerated cellulose fiber matrix, wherein alginate molecular chains are connected with the regenerated cellulose molecular chains through a cross-linking agent.

The reported production process of the modified natural polymer fiber is wet spinning or dry-jet wet spinning, namely, after dissolving the sodium alginate grafted cellulose pulp to prepare a spinning solution, taking water or a polyvalent metal salt ion solution as a coagulating bath, and carrying out wet spinning to prepare the alginate modified regenerated cellulose fiber. At present, the modified natural polymer fiber is generally prepared by a wet spinning method, an ion cross-linking network is formed in natural macromolecules, and the defects of poor and uneven mechanical properties, poor functionality and the like of a modified fiber material exist.

Disclosure of Invention

The invention aims to provide a preparation method of an inorganic nanoparticle dynamic crosslinking double-network modified natural polymer material, which is double-network fiber or film or fiber aerogel with an inorganic nanoparticle structure and good dynamic crosslinking, reinforcing and toughening effects.

The purpose of the invention is realized by the following steps: a method for preparing a modified natural polymer material with an inorganic nanoparticle dynamic cross-linking double-network structure is prepared by a one-pot method and comprises the following steps:

under the stirring condition of nitrogen protection, adding double bond-containing organic monomers and inorganic nanoparticles (VSNP) into a natural high molecular compound solution, adding an initiator, and carrying out free radical polymerization at 30-50 ℃ for 12-36h to obtain a blending solution; after the reaction is finished, the blending solution enters the coagulant solution for coagulation forming through a wet spinning method, an electrostatic spinning method or a centrifugal spinning method to prepare a fiber material, or the mixing solution is subjected to film forming through a tape casting method and then enters the coagulant solution for coagulation forming to prepare a film material.

Wherein the preparation method of the inorganic nano-particles (VSNPs) comprises the following steps: hydrolyzing the double-bond-containing silicon-based inorganic precursor in ethanol or methanol and water mixed solution with pH = 4-5 at room temperature (generally 25 ℃) for 20-60min until the precursor is clear and transparent to obtain a hydrolysis product VSNP;

the mass concentration of the natural polymer compound solution is 1-2%; the double bond-containing organic monomer accounts for 1-30% of the mass fraction of the natural high molecular compound, preferably 15%; the inorganic nano particles account for 0.5 to 9 percent, preferably 7 percent of the mass fraction of the double bond-containing organic monomer; the initiator accounts for 1 to 10 percent, preferably 2 percent of the mass fraction of the double bond-containing organic monomer; the mass concentration of the coagulant solution is 1 to 5%, preferably 3%.

The dynamic cross-linked double-network structure is generated by the synergistic effect of covalent bonds, dynamic hydrogen bonds, ionic cross-linking and interpenetrating interlocking. The active double bonds of inorganic nano particles and organic monomers containing double bonds are copolymerized into hybrid flexible long chains, natural polymer chains are synchronously introduced by a one-pot method, a natural polymer ion crosslinking network is used as a rigid first network, dynamic hydrogen bonds are pseudo-crosslinked to form a flexible second network, a dynamic crosslinking double-network structure is formed, intermolecular action and rheological behavior are regulated and controlled, and the fibers are formed by ionic crosslinking gelation in a coagulant solution.

According to the above technical solution, preferably, the double bond-containing silicon-based inorganic precursor is selected from at least one of vinyltriethoxysilane, gamma-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane and the like.

According to the above technical solution, preferably, the double bond-containing organic monomer is at least one of Acrylic Acid (AA), acrylamide, polyethylene glycol diacrylate and derivatives thereof.

According to the above technical scheme, preferably, the initiator is selected from at least one of Ammonium Persulfate (APS), potassium persulfate, sodium persulfate, hydrogen peroxide and benzoyl peroxide.

According to the above technical solution, preferably, the natural polymer compound is selected from at least one of Sodium Alginate (SA), chitosan, cellulose, and protein.

According to the above technical scheme, preferably, the molecular weight of the natural polymer compound is 3 × 10 ⁶ -5×10 ⁶ g/mol。

According to the technical scheme, the time for solidification forming is preferably 1-10min, and the solidification forming coagulant is a divalent or trivalent metal ion compound, or dicarboxylic acid, urea or dialdehyde. The divalent or trivalent metal ion compound may be CaCl ₂ 、CuSO ₄ 、ZnSO ₄ The dicarboxylic acids are, above all, adipic Acid (AA), also azelaic acid (AZA), sebacic anhydride (CSA), isophthalic acid (IPA), terephthalic acid (IPA), dimethyl terephthalate (DMTP) and the like, and the dialdehydes are glyoxal, malondialdehyde and the like. When the natural high molecular compound is sodium alginate, the coagulant is a divalent or trivalent metal ion compound; when the natural high molecular compound is chitosan, cellulose or protein, the coagulant is dicarboxylic acid, urea or dialdehyde.

According to the above technical solution, preferably, the volume ratio of ethanol or methanol to water is 1.

According to the above technical solution, preferably, the diameter of the spinneret orifice in the wet spinning process is 0.5-0.9mm, preferably 0.7mm; the extrusion rate is 5-15mm/min, preferably 9mm/min.

According to the above technical scheme, preferably, the blend solution is spun into fibers, and then the fibers are washed, drawn and dried to obtain finished fibers.

According to the above technical scheme, preferably, the mixed solution is formed into a film by a tape casting method, and the film is dried and then solidified and formed in a coagulant solution to prepare a film material.

According to the above technical scheme, preferably, the fiber aerogel is obtained by preparing the blend solution into fibers, washing with water, and freeze-drying.

According to the technical scheme, the freeze drying temperature is-40 to-55 ℃, the pressure is 40 to 60Pa, and the time is 24 to 48 hours.

According to the above technical scheme, the adding mode is preferably dropwise adding, and is preferably dropwise adding.

In addition, the invention also relates to a reinforced natural polymer material with the inorganic nanoparticle dynamic crosslinking double-network structure, which is prepared by the method and comprises a fiber material, a membrane material and a fiber aerogel material.

The invention provides a brand-new one-step method inorganic nanoparticle dynamic cross-linking double-network structure reinforced sodium alginate fiber preparation process, which comprises the steps of dissolving a natural high molecular compound (such as Sodium Alginate (SA)), adding a double bond-containing organic monomer (such as Acrylic Acid (AA), inorganic nanoparticles (VSNP) and an initiator (such as APS) after completely forming a solution, raising the temperature under the protection of nitrogen to initiate free radical polymerization, so that the natural high molecular compound (such as SA) and the double bond-containing organic monomer (such as Acrylic Acid (AA)) are interpenetrated in the polymerization reaction process, and simultaneously, the natural high molecular compound and the VSNP are subjected to dynamic cross-linking reaction, and after the polymerization reaction is carried out to a certain degree, a coagulant (such as CaCl) is added ₂ ) In (1), coagulant (such as Ca) ²⁺ ) The crosslinked natural high molecular compound (such as SA) and pseudo-crosslinked polyacrylic acid (PAA) form a DN structure, so that the sodium alginate fiber or film with the inorganic nano particle dynamic crosslinking DN structure is formed.

The beneficial effects of the invention are:

the enhancement of the network by adding inorganic nanoparticles is an emerging method for modifying natural polysaccharide polymers, and the modification method achieves the aim of modifying natural polymers by forming an enhancement network through the interaction between polymers and nanoparticles. The inorganic nano particles are added into the polymer to combine the inorganic nano particles and the polymer through weak acting force (such as Van der Waals force and hydrogen bonds) or strong acting force (such as covalent bonds, ionic bonds and coordination bonds), and the processes of generation, dissociation and the like exist in the processing process, so that dynamic crosslinking can be realized, dynamic change can be realized, and the thermal stability, the mechanical property and the dimensional stability of the polymer can be obviously enhanced. The inorganic nano particle dynamic cross-linking double-network structure reinforced natural polymer fiber is prepared by taking a double-network structure as a core and fixing inorganic nano particles in the existing natural polymer, wherein the inorganic nano particles and the double-network structure are shaped in the fiber and are subjected to dynamic cross-linking. For inorganic nano particles and double-network structure dynamic cross-linking natural polymer materials, the inorganic nano particles and the double-network structure promote the dynamic cross-linking and network homogenization of the natural polysaccharide polymer materials, increase the mechanical properties of the natural polysaccharide polymer materials and widen the application field of the natural polysaccharide polymer materials.

The invention is based on the design of a double-network structure, prepares a strong-tenacity fiber material with inorganic nano-particle VSNP dynamic crosslinking, which not only comprises interpenetrating interlocking of molecular chains of a polymer (such as PAA) obtained by polymerizing a natural high molecular compound (such as SA) and an organic monomer containing double bonds, but also comprises dynamic hydrogen bonds between the VSNP and the natural high molecular compound (such as SA) and the polymer (such as PAA) obtained by polymerizing the organic monomer containing double bonds and Ca in Calcium Alginate (CA) formed by solidifying and crosslinking the natural high molecular compound ²⁺ Non-covalent dynamic crosslinking such as ionic crosslinking. The dynamic hydrogen bonds of the silicon-based nanoparticles in the organic interphase long and narrow macroporous gaps and the interpenetrating interlocking framework structure of the double networks can homogenize the network structure and realize forced mutual compatibility. The dynamic cross-linking structure design can avoid the adverse effects of the weak gel effect of the chemical cross-linking type gel liquid on wet spinning and toughness, and a complete continuous non-particle type framework structure is formed. Introduction of silicon-based nanoparticles by bonding and dynamic cross-linking of organic double networksComplexing, improving hybridization fastness, solving the continuity of the framework, enhancing the strength of the framework, reducing the density and saving the long aging time for forming stable connection of silicon-based particles. The synergistic dynamic hydrogen bond, ionic crosslinking, double-net interlocking and other dynamic non-covalent sacrificial bond functions realize energy dissipation during shrinkage and stress, and enhance toughness. The biomass raw material is selected as the main raw material, the 'one-pot' water system processing and the common drying condition are selected, and the efficiency and the environmental friendliness are improved. The inorganic nano particles are immobilized in the double networks, so that the immobilization effect is good, and the mechanical property of the fiber is outstanding; the preparation process is simple, the molding can be well carried out under normal pressure, low rotating speed and low temperature, and the yield is high; the DN type cross-linked structure has better mechanical property, effectively improves the defects of the existing product, can make up the defects of breaking strength and breaking elongation of the traditional wet spinning method, has the defects of high price of the carrier, poor stability, poor fluidity, mostly blocky macroscopic form, single application range and the like, and widens the application range of inorganic nano particles and natural polymer fiber materials.

(1) The invention adopts the one-pot method for preparation, the inorganic nano particles, AA and SA generate pseudo-crosslinking reaction and are interlocked and immobilized by a double-network structure, and the fiber or membrane material with the double-network structure is generated.

(2) The first network Calcium Alginate (CA) and the second network PAA molecular chain are interpenetrated and intertwined to form a double-network interlocking structure, which jointly form a framework of the fiber material, wherein the inorganic nano-particle VSNP initiates AA to perform free radical polymerization to generate a flexible chain structure of PAA. The 'dynamic sacrificial bond' exists between the partial crimp chain structure of VSNP and PAA and CA, so that the performance, especially the mechanical property, of the natural polymer fiber material is improved.

(3) The application of the CA fiber prepared by the traditional wet spinning method is limited due to the defect of mechanical property, the inorganic nanoparticle dynamic crosslinking double-network structure synergistic reinforced toughened sodium alginate fiber provided by the invention has the advantages that the mechanical property of the sodium alginate fiber is greatly improved, the advantages of an inorganic nanoparticle material and the double-network structure are combined into a whole, the chemical structure of double-network components can be comprehensively regulated and controlled, and the microcosmic and appearance morphological structure can be regulated and controlled, so that the CA fiber is applied to various fields of natural polymer fiber materials, such as textiles, aerospace, sporting goods, medical treatment and the like. And different double-network immobilized components can be selected to realize more functions such as light, electricity and the like based on the regulation mechanism of the chemical structure and the morphological structure of the compound.

The natural polymer fiber material prepared by the invention has excellent performance and simple preparation method, the used raw materials are cheap and easy to obtain, and the cost is lower; the natural polymer fiber material reserves a first network structure of CA, realizes a skeleton structure required by the mechanical property of the fiber material, and provides a structural design basis for further functionalization; the invention effectively improves the mechanical property of the natural polymer fiber, the breaking strength reaches 3.68cN/dtex, the elongation at break is 13.65 percent, compared with the pure SA fiber, the invention respectively improves 83.08 percent and 65.45 percent, and also can enhance the mechanical property of the natural polymer film. The inorganic nano particle dynamic crosslinking double-network structure has obvious reinforcing and toughening effects, and can be applied to the fields of textiles, aerospace, sports goods, medical treatment and the like.

Drawings

FIG. 1 is an IR spectrum of a fibrous material prepared in example 8.

FIG. 2 shows the mechanical properties of the fibers prepared in comparative example 1, example 2, example 3, example 4 and example 5.

FIG. 3 is a graph showing the mechanical properties of fibers prepared in comparative example 2, example 6, example 7, example 8, and example 9.

FIG. 4 is SEM images of fibers prepared in comparative example 2, example 2 and example 8, wherein A and a are SEM images of the surface and cross-section of the fiber of comparative example 2, respectively, and B and B are SEM images of the surface and cross-section of the fiber of example 2, respectively; c and C are SEM images of the surface and cross-section of the fiber of example 8, respectively.

Fig. 5 is an EDS image of the fiber prepared in example 8.

FIG. 6 shows TG and DTG of the fibers prepared in example 1, example 2, example 3, example 4, example 5, example 6, example 7, example 8 and example 9 (A and B: a, B, C, D and e respectively represent PAA contents of 10%,15%,20%,25% and 30%, and C and D: a, B, C, D and e respectively represent VSNP contents of 1%,3%,5%,7% and 9%).

Fig. 7 is a contact angle image of the film prepared in example 17.

Detailed Description

The following non-limiting examples will allow one of ordinary skill in the art to more fully understand the present invention, but are not intended to limit the invention in any way.

The invention is further illustrated with reference to the accompanying drawings and the specific examples.

Sodium Alginate (SA) in the examples below has a molecular weight of 5X 10 ⁶ g/mol。

The mechanical properties of the inorganic nanoparticle dynamically crosslinked double-network structure reinforced sodium alginate fiber in the following examples are tested by an LL-06E type electronic single-fiber strength tester.

Comparative example 1

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

Using ethanol: deionized water =1 ratio 1ml of VTES was diluted to 5%, the pH of the above solution was adjusted with acetic acid =4 to 5, and the resulting solution was stirred at room temperature for 40min to be clear and transparent, yielding a hydrolysate VSNP.

(2) Preparation of SA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution, and 0.3ml of VSNP was added dropwise to the SA solution with stirring using a titrator, and reacted for 24 hours under a water bath at 40 ℃ and nitrogen protection to obtain an SA-VSNP blended solution.

(3) Preparation of SA-VSNP fibers

Extruding the SA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min by a variable frequency stepper, and feeding CaCl with the mass concentration of 3% ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA-VSNP fiber (PAA: 0%; VSNP: 5%).

Example 1

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

Using ethanol: deionized water =1 ratio 1ml of VTES was diluted to 5%, pH =4 to 5 of the above solution was adjusted with acetic acid, and the resulting solution was stirred at room temperature for 40min until clear and transparent to obtain hydrolysate VSNP.

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.2ml of AA monomer and 0.2ml of VSNP hydrolyzed in the previous step are dropwise added into the SA solution by using a titrator, then 0.004g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection, so that the SA/PAA-VSNP blending solution is obtained.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min through a variable frequency stepper, and feeding the extruded SA/PAA-VSNP spinning solution into CaCl with the mass concentration of 3% ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 10%; VSNP: 5%).

Example 2

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.3ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blended solution.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min through a variable frequency stepper, and feeding the extruded SA/PAA-VSNP spinning solution into CaCl with the mass concentration of 3% ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 15%; VSNP: 5%).

Example 3

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.4ml of AA monomer and 0.4ml of VSNP hydrolyzed in the previous step are dropwise added into the SA solution by using a titrator, then 0.008g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection, so that the SA/PAA-VSNP blending solution is obtained.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min by a variable-frequency stepper, and feeding CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 20%; VSNP: 5%).

Example 4

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution; under the stirring condition, 0.5ml of AA monomer and 0.5ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.01g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blending solution.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min by a variable-frequency stepper, and feeding the SA/PAA-VSNP spinning solution into a spinning machine with the mass concentration of 3 percentIn (C) is ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 25%; VSNP: 5%).

Example 5

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g of SA, adding into a 100ml beaker, and preparing a 2% SA solution; under the stirring condition, 0.6ml of AA monomer and 0.6ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.012g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blending solution.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min by a variable-frequency stepper, and feeding CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 30%; VSNP: 5%).

Comparative example 2

(1) Preparation of SA/PAA blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.3ml of AA monomer is dropwise added into the SA solution by using a titrator, then 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA blending solution.

(2) Preparation of SA/PAA fibers

Extruding the SA/PAA spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min by a variable frequency stepper, and feeding the extruded SA/PAA spinning solution into CaCl with the mass concentration of 3% ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA fiber (PAA: 15%; VSNP: 0%).

Example 6

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.06ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection, so that the SA/PAA-VSNP blending solution is obtained.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min through a variable frequency stepper, and feeding the extruded SA/PAA-VSNP spinning solution into CaCl with the mass concentration of 3% ₂ Solidifying and forming in the solution, after 5min of solidification, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 15%; VSNP: 1%).

Example 7

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.18ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blending solution.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min through a variable-frequency stepper, and feeding the SA/PAA-VSNP spinning solution into a spinning machine with the mass concentration of 3 percentCaCl ₂ Solidifying and forming in the solution, after 5min of solidification, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 15%; VSNP: 3%).

Example 8

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.42ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection, so that the SA/PAA-VSNP blending solution is obtained.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min through a variable frequency stepper, and feeding the extruded SA/PAA-VSNP spinning solution into CaCl with the mass concentration of 3% ₂ Solidifying and forming in the solution, after solidifying for 5min, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 15%; VSNP: 7%).

Example 9

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.54ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection, so that the SA/PAA-VSNP blending solution is obtained.

(3) Preparation of SA/PAA-VSNP fiber

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min through a variable frequency stepper, and feeding the extruded SA/PAA-VSNP spinning solution into CaCl with the mass concentration of 3% ₂ Solidifying and forming in the solution, after 5min of solidification, washing, drafting and drying at room temperature to constant weight to obtain the SA/PAA-VSNP fiber (PAA: 15%; VSNP: 9%).

Example 10

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution; under the stirring condition, 0.2ml of AA monomer and 0.2ml of VSNP hydrolyzed in the previous step are dropwise added into the SA solution by using a titrator, then 0.004g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection, so that the SA/PAA-VSNP blending solution is obtained.

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blast drying oven for air-blast drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is pulled off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing with water and drying at room temperature to constant weight to obtain the SA/PAA-VSNP film (PAA: 10%; VSNP: 5%).

Example 11

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.3ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blended solution.

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blowing drying box for air-blowing drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is lifted off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing with water and drying at room temperature to constant weight to obtain the SA/PAA-VSNP film (PAA: 15%; VSNP: 5%).

Example 12

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blast drying oven for air-blast drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is pulled off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing with water and drying at room temperature to constant weight to obtain the SA/PAA-VSNP film (PAA: 20%; VSNP: 5%).

Example 13

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.5ml of AA monomer and 0.5ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.01g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blending solution.

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blast drying oven for air-blast drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is pulled off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing with water and drying at room temperature to constant weight to obtain the SA/PAA-VSNP film (PAA: 25%; VSNP: 5%).

Example 14

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.6ml of AA monomer and 0.6ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.012g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blending solution.

(3) Preparation of SA/PAA-VSNP Membrane

30ml of SA/PAA-VSNP blend solution was drawn using a 30ml syringe and extruded into framed plastic petri dishes (diameter =90mm, height =14 mm)Then the powder is put into a 40 ℃ blast drying oven for blast drying for 5 hours, and after the powder is dried, the powder is taken off and put into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after 5min of solidification, washing with water and drying to constant weight at room temperature to obtain the SA/PAA-VSNP film (PAA: 30%; VSNP: 5%).

Example 15

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution; 0.3ml of AA monomer and 0.06ml of VSNP hydrolyzed as above were added dropwise to the SA solution using a titrator under stirring, followed by addition of 0.006g of APS. And reacting for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain an SA/PAA-VSNP blending solution.

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blast drying oven for air-blast drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is pulled off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing with water and drying at room temperature to constant weight to obtain the SA/PAA-VSNP film (PAA: 15%; VSNP: 1%).

Example 16

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

Weighing 2g SA, adding into 100ml beaker, concocting into 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.18ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection, so that the SA/PAA-VSNP blending solution is obtained.

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blowing drying box for air-blowing drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is lifted off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing with water and drying at room temperature to constant weight to obtain the SA/PAA-VSNP film (PAA: 15%; VSNP: 3%).

Example 17

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

2g of SA was weighed and added to a 100ml beaker to prepare a 2% SA solution; under the stirring condition, 0.3ml of AA monomer and 0.42ml of VSNP after hydrolysis are dropwise added into the SA solution by using a titrator, then 0.006g of APS is added, and the mixture is reacted for 24 hours under the conditions of water bath at 40 ℃ and nitrogen protection to obtain the SA/PAA-VSNP blending solution.

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blast drying oven for air-blast drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is pulled off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after solidifying for 5min, washing with water and drying at room temperature to constant weight to obtain the SA/PAA-VSNP film (PAA: 15%; VSNP: 7%).

Example 18

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

(3) Preparation of SA/PAA-VSNP Membrane

Using a 30ml syringe, 30ml of the SA/PAA-VSNP blending solution is extracted and extruded into a plastic culture dish with a frame (the diameter is =90mm, the height is =14 mm), then the plastic culture dish is placed into a 40 ℃ air-blast drying oven for air-blast drying for 5h, and after the plastic culture dish is dried, the plastic culture dish is pulled off and placed into CaCl with the mass concentration of 3 percent ₂ Solidifying and forming in the solution, after 5min of solidification, washing with water and drying to constant weight at room temperature to obtain the SA/PAA-VSNP film (PAA: 15%; VSNP: 9%).

Example 19

(1) Hydrolysis of Vinyltriethoxysilane (VTES)

(2) Preparation of SA/PAA-VSNP blend solution

(3) Preparation of SA/PAA-VSNP fiber aerogel

Extruding the SA/PAA-VSNP spinning solution from a spinneret orifice with the aperture of 0.7mm at the speed of 9mm/min through a variable frequency stepper, and feeding the extruded SA/PAA-VSNP spinning solution into CaCl with the mass concentration of 3% ₂ Solidifying in solution, solidifying for 5min, and adding waterWashing, and freeze-drying in a vacuum freeze-drying machine at-50 deg.C and 50Pa for 48 hr to obtain SA/PAA-VSNP fiber aerogel (PAA: 15%; VSNP: 7%).

FIG. 1 is an IR spectrum of SA/PAA-VSNP fibers prepared in example 8. From FIG. 1, it can be seen that SA/PAA-VSNP fibers obtained in example 8 have a broadened peak of stretching vibration of-OH and a red shift, compared with pure SA fibers, indicating strong hydrogen bonding between SA, PAA and VSNP.

Fig. 2 is the mechanical properties of the fibers prepared in comparative example 1, example 2, example 3, example 4, and example 5, and it can be seen from fig. 2 that the breaking strength and breaking elongation of the fibers increase and then decrease with the increase of PAA content. The SA/PAA-VSNP fiber has the best mechanical property when the PAA content is 15 percent.

Fig. 3 is a graph showing the mechanical properties of the fibers prepared in comparative example 2, example 6, example 7, example 8 and example 9, and it can be seen from fig. 3 that the breaking strength of the fibers increases with the increase of the content of VSNP and the elongation at break increases first and then decreases with the increase of the content of VSNP. When the content of the VSNP is 7%, the mechanical property of the SA/PAA-VSNP fiber is optimal, the breaking strength reaches 3.68cN/dtex, the elongation at break reaches 13.65%, and the fiber is respectively improved by 83.08% and 65.45% compared with the pure SA fiber.

FIG. 4 is an SEM image of fibers prepared in comparative example 2, and example 8, wherein A and a are SEM images of the surface and cross-section of the fibers of comparative example 2, respectively, and B and B are SEM images of the surface and cross-section of the fibers of example 2, respectively; c and C are SEM images of the surface and cross-section of the fiber of example 8, respectively; as can be seen from the figure, after PAA and VSNP were introduced into the system, the fiber surface was smoother and inorganic nanoparticles began to appear inside the fiber.

Fig. 5 is an EDS image of the fiber prepared in example 8, and it can be seen from fig. 5 that Ca and Si are uniformly distributed in the interior of the fiber.

FIG. 6 shows TG and DTG of the fibers prepared in examples 1, 2, 3, 4, 5, 6, 7, 8, 9 (A and B: a, B, C, D and e represent PAA content of 10%,15%,20%,25% and 30%, respectively; C and D: a, B, C, D and e represent VSNP content of 1%,3%,5%,7% and 9%, respectively), and it can be seen from FIG. 6 that the thermal properties of the fibers are continuously improved as the PAA and VSNP content is increased.

Fig. 7 is a contact angle image of the membrane prepared in example 17, and it can be seen from fig. 7 that when the PAA content is 15% and the VSNP content is 7%, the contact angle of the prepared membrane material is 33.7 °, which has strong hydrophilicity because a large amount of hydrophilic group — OH is introduced into the system with the introduction of VSNP.

It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention shall still fall within the protection scope of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.

Claims

1. A preparation method of an inorganic nanoparticle dynamic cross-linking double-network modified natural polymer material is characterized by comprising the following steps:

adding inorganic nanoparticles and double bond-containing organic monomers into a natural high molecular compound solution under the stirring condition of nitrogen protection, then adding an initiator, and reacting at 30-50 ℃ for 12-36h to obtain a blending solution; after the reaction is finished, the blended solution enters a coagulant solution for coagulation forming through a wet spinning, electrostatic spinning or centrifugal spinning method to prepare a fiber material, or the mixed solution is subjected to film forming through a tape casting method and then enters the coagulant solution for coagulation forming to prepare a film material;

the preparation method of the inorganic nano-particles comprises the following steps: hydrolyzing the double-bond-containing silicon-based inorganic precursor in ethanol or methanol and water mixed solution with pH = 4-5 for 20-60min at room temperature to obtain a hydrolysis product; the volume concentration of the double-bond-containing silicon-based inorganic precursor is 3-7 percent;

the double-bond-containing silicon-based inorganic precursor is selected from at least one of vinyl triethoxysilane, gamma-methacryloxypropyl trimethoxysilane and vinyl trimethoxysilane; the double bond-containing organic monomer is at least one of acrylic acid, acrylamide, polyethylene glycol diacrylate or derivatives thereof; the natural high molecular compound is selected from at least one of sodium alginate, chitosan, cellulose and protein; the initiator is selected from at least one of ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide and benzoyl peroxide; the coagulant is a divalent or trivalent metal ion compound, or dicarboxylic acid, urea or dialdehyde;

the mass concentration of the natural high molecular compound solution is 1-2%, the double bond-containing organic monomer accounts for 1-30% of the mass fraction of the natural high molecular compound, the inorganic nano particles account for 0.5-9% of the mass fraction of the double bond-containing organic monomer, and the initiator accounts for 1-5% of the mass fraction of the double bond-containing organic monomer; the mass concentration of the coagulant solution is 1-5%.

2. The method for preparing the inorganic nanoparticle dynamically crosslinked double-network structure modified natural polymer material as claimed in claim 1, wherein the molecular weight of the natural polymer compound is 3 x 10 ⁶ -5×10 ⁶ g/mol。

3. The method for preparing the inorganic nanoparticle dynamically crosslinked double-network structure modified natural polymer material according to claim 1, wherein the time for solidification molding is 1-10min.

4. The method for preparing the inorganic nanoparticle dynamically crosslinked double-network structure modified natural polymer material according to claim 1, wherein the volume ratio of ethanol or methanol to water is 1.5-1.

5. The method for preparing the inorganic nanoparticle dynamically crosslinked double-network structure modified natural polymer material according to claim 1, wherein the blend solution is made into fibers, and the fibers are washed, drawn and dried to obtain finished fibers; the aperture of a spinneret orifice is 0.3-1.5mm in the wet spinning process, and the extrusion rate is 5-15mm/min; and preparing the blended solution into fibers, washing with water, and freeze-drying to obtain the fiber aerogel.

6. The method for preparing the inorganic nanoparticle dynamically crosslinked double-network structure modified natural polymer material according to claim 1, wherein the adding manner is dropwise.

7. The inorganic nanoparticle dynamically crosslinked double-network structure modified natural polymer material prepared by the method of any one of claims 1 to 6.