Oil-soluble core-crosslinked fibrous nanofiller and polymer-nanofiller composite material prepared from same

Abstract

The invention provides an oil-soluble core-crosslinked fibrous nanofiller and a polymer-nanofiller composite material prepared from the oil-soluble core-crosslinked fibrous nanofiller. The preparation method comprises the following steps: preparing oil-soluble and core-crosslinked polymer nanofibers through in-situ crosslinking polymerization induced self-assembly; and uniformly mixing the polymer elastomer and the nanofibers through an internal mixer to prepare the polymer nanofiller composite material. The preparation method has the advantages that (1) the preparation efficiency is very high; (2) the polymer nanofiber and various hydrophobic polymers have good compatibility; (3) the fibrous structure of the polymer nanofiber can be kept in a high-temperature and high-shear processing environment without disintegration, so that a more excellent reinforcing effect is achieved; (4) the polymer nanofiber can improve the tensile strength, the elongation and the toughness of the polymer matrix at the same time; and (5) the enhancement mechanism does not need to sacrifice the transparency, repeatable processability and self-healing performance of the polymer nanofiber composite material.

Description

Technical Field

[0001] This invention relates to the field of polymer nanomaterials, specifically to an oil-soluble, core-crosslinked fibrous nanofiller and a polymer-nanofiller composite material prepared therefrom. Background Technology

[0002] Mechanical properties are one of the fundamental characteristics determining the application and durability of polymer materials, hence continuous efforts have been made to improve them. Currently, among various commercially available polymer materials, covalent cross-linking is the preferred strategy for enhancing material performance. This strategy allows the formation of a cross-linked polymer network within the material, enabling it to withstand higher stresses without chain slippage. However, this strategy for improving material strength often comes at the cost of sacrificing toughness, recyclability, and self-healing properties.

[0003] Introducing rigid nanofillers (such as clay, silica spheres, carbon nanotubes, graphene, and glass fibers) into polymer matrices is another commonly used method for reinforcing polymer materials. Compared to spherical nanofillers, fibrous nanofillers (such as carbon nanotubes and glass fibers) can achieve better reinforcing effects at lower dosages. However, the poor compatibility between inorganic nanofillers and the polymer matrix leads to poor dispersion in the composite material, resulting in poor reinforcing effects and a tendency for the composite material to age more easily. Furthermore, polymer composites obtained using inorganic nanofillers also exhibit poor transparency. Fibrous polymer nanofillers prepared by electrospinning exhibit better reinforcing effects due to their good compatibility with the polymer substrate; however, the low efficiency of electrospinning hinders the large-scale industrial production and application of fibrous polymer nanofillers.

[0004] Polymerization-induced self-assembly (PISA) is an efficient method for preparing polymer nanomaterials (including nanofibers). The PISA strategy combines the synthesis and self-assembly of block polymers into a single step, effectively simplifying the preparation process of polymer nanofibers and enabling their preparation at high concentrations (up to 50 wt% solids). Currently, the PISA strategy is mainly used to prepare water-soluble polymer nanomaterials because water-soluble nanomaterials have broad application prospects in biomedicine and tissue engineering, and water is a green and environmentally friendly solvent. However, most commercially available polymers are hydrophobic. As nano-additives, oil-soluble nanofibers are undoubtedly a better choice because they have better compatibility with hydrophobic polymers. Furthermore, considering the harsh environment (such as high temperature and high shear processes) in the production of polymer-nanofiller composites, the structural stability of polymer nanofibers is another important issue determining their industrial application prospects.

[0005] In summary, high-quality fibrous nanofillers should possess the following properties: (1) extremely high preparation efficiency; (2) excellent compatibility with polymer matrices; (3) excellent structural stability to withstand harsh processing environments; (4) the ability to simultaneously improve the strength, elongation, and toughness of polymer nanofiller composites; and (5) a reinforcement mechanism that does not require sacrificing the transparency, recyclability, and self-healing ability of the polymer nanofiller composites. Undoubtedly, combining these five excellent properties into a single nanofiber will greatly promote the industrial application of polymer nanofibers, and the resulting composite material will meet the needs of human sustainable development. However, this remains a considerable challenge. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an oil-soluble, core-crosslinked fibrous nanofiller and its preparation method.

[0007] Another object of the present invention is to provide the application of oil-soluble and nucleocrosslinked fibrous nanofillers.

[0008] Another object of the present invention is to provide a polymer-nanofiber composite material prepared from oil-soluble and core-crosslinked fibrous nanofillers.

[0009] The objective of this invention can be achieved through the following technical means:

[0010] A method for preparing an oil-soluble, core-crosslinked fibrous nanofiller includes the following steps:

[0011] 1) Dissolve monomer M1, diacid A1, and acid-binding agent in a solvent and initiate an esterification reaction to obtain crosslinking agent C1, wherein M1 is a monomer containing esterification reaction sites and double bonds.

[0012] 2) Dissolve monomer M2, chain transfer agent CTA, and initiator in a solvent and initiate polymerization to obtain oil-soluble macromolecular chain transfer agent P2-CTA, where P2 is a polymer and CTA is a chain transfer agent containing polymeric active ends;

[0013] 3) P2-CTA, monomer M3, crosslinking agent C1 and initiator are dissolved in a solvent and polymerization is initiated to obtain an oil-soluble and core-crosslinked fibrous nanofiller, wherein the surface chain segment of the fibrous nanofiller is the oil-soluble polymer P2 and the core chain segment is the crosslinked polymer P3.

[0014] Preferably, in step 1), monomer M1 is 4-chloromethylstyrene, diacid A1 is 1,6-adipic acid, and the acid-binding agent is selected from any one of pyridine, triethylamine, sodium carbonate, potassium carbonate, and sodium acetate; more preferably, potassium carbonate, and the solvent is dimethylformamide, tetrahydrofuran, or dimethyl sulfoxide.

[0015] Preferably, in step 2), the monomer M2 is octadecyl methacrylate, the oil-soluble polymer is polyoctadecyl methacrylate (SMA), the chain transfer agent CTA is PETTC (4-cyano-4-[(phenylethylthioalkylthiocarbonyl)thioalkyl]valerate), and the solvent is either toluene or mineral oil.

[0016]

[0017] Preferably, in step 3), the monomer M3 is styrene, the molar ratio of the oil-soluble macromolecular chain transfer agent P2-CTA to the crosslinking agent C1 is 1:(2-10), preferably 1:2; and the solvent is toluene.

[0018] Preferably, the initiator mentioned in steps 2) and 3) is selected from any one of azo compounds, peroxides, disulfides, and compounds containing NO bonds; preferably, it is one of azobisisobutyronitrile (AIBN) and tert-butyl peroxide (TBPB).

[0019] Oil-soluble, core-crosslinked fibrous nanofillers prepared according to the preparation method described above.

[0020] The application of the oil-soluble and core-crosslinked fibrous nanofiller in the preparation of polymer-nanofiber composite materials.

[0021] A polymer-nanofiber composite material is prepared from the oil-soluble and core-crosslinked fibrous nanofiller; preferably, the oil-soluble and core-crosslinked fibrous nanofiller is incorporated into a polymer matrix in a certain proportion, and then mechanically stirred and mixed evenly in an internal mixer to prepare the polymer-nanofiber composite material; wherein, the temperature of the internal mixer is the melting or viscous flow temperature of the polymer matrix, preferably 50-300℃.

[0022] Preferably, the polymer base is prepared by soap-free emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (nBA) mixed in water.

[0023] Preferably, the oil-soluble and core-crosslinked fibrous nanofiller is incorporated in an amount of (0.1-5)% of the total weight of the polymer substrate, preferably 1%.

[0024] Beneficial effects: The present invention provides an oil-soluble and core-crosslinked fibrous nanofiller and a polymer-nanofiber composite material prepared therefrom. The advantages of the fibrous nanofiller include the following aspects: (1) The preparation efficiency of polymer nanofibers is very high (solid content is 15wt%); (2) The surface of the fibrous nanofiller is an oil-soluble polymer, which has good compatibility with the hydrophobic polymer matrix; (3) The fibrous nanofiller has a core-crosslinked structure, which is very stable, so that it can maintain its fibrous structure without disintegration in high temperature and high shear processing environment, and can withstand harsh processing environments such as high temperature and high shear, thus having a better reinforcing effect; (4) The fibrous nanofiller can simultaneously improve the tensile strength, elongation and toughness of polymer materials; and (5) The reinforcing mechanism of the fibrous nanofiller does not sacrifice the transparency, recyclability and self-healing ability of the resulting composite material. Attached Figure Description

[0025] Figure 1 The PSMA prepared in Example 1 of this invention via in-situ crosslinking polymerization-induced self-assembly strategy is shown. 21 -bP(St 260 TEM image of -co-BVBA2) nanofibers;

[0026] Figure 2 The PSMA prepared in Example 1 of this invention using a conventional polymerization-induced self-assembly strategy is shown. 21 -b-PSt 260 TEM image of nanofibers;

[0027] Figure 3 The DOSY NMR spectrum of P(MMA-stat-nBA) obtained in Example 2 of this invention;

[0028] Figure 4 The GPC curve of P(MMA-stat-nBA) obtained in Example 2 of this invention;

[0029] Figure 5 The stress-strain curve of the P(MMA-stat-nBA) substrate material obtained in Example 3 of this invention (5 parallel repeated experiments);

[0030] Figure 6 The product containing 0.1 wt% PSMA obtained in Example 4 of this invention 21 -bP(St 260 Stress-strain curves of composite materials made of -co-BVBA2 nanofibers (6 parallel repeated experiments);

[0031] Figure 7 The sample containing 0.1 wt% PSMA obtained in Comparative Example 1 of this invention21 -b-PSt 260 Stress-strain curves of nanofiber composite materials (6 parallel repeated experiments);

[0032] Figure 8 The product containing 0.5 wt% PSMA obtained in Example 5 of this invention 21 -bP(St 260 Stress-strain curves of composite materials made of -co-BVBA2 nanofibers (6 parallel repeated experiments);

[0033] Figure 9 The sample containing 0.5 wt% PSMA obtained in Comparative Example 2 of this invention 21 -b-PSt 260 Stress-strain curves of nanofiber composite materials (6 parallel repeated experiments);

[0034] Figure 10 The product containing 1.0 wt% PSMA obtained in Example 6 of this invention 21 -bP(St 260 Stress-strain curves of composite materials made of -co-BVBA2 nanofibers (6 parallel repeated experiments);

[0035] Figure 11 The product containing 1.0 wt% PSMA obtained in Comparative Example 3 of this invention 21 -b-PSt 260 Stress-strain curves of nanofiber composite materials (6 parallel repeated experiments);

[0036] Figure 12 The product containing 3.0 wt% PSMA obtained in Example 7 of this invention 21 -bP(St 260 Stress-strain curves of composite materials made of -co-BVBA2 nanofibers (6 parallel repeated experiments);

[0037] Figure 13 The product containing 3.0 wt% PSMA obtained in Comparative Example 4 of this invention 21 -b-PSt 260 Stress-strain curves of nanofiber composite materials (6 parallel repeated experiments);

[0038] Figure 14 The product containing 5.0 wt% PSMA obtained in Example 8 of this invention 21 -bP(St 260 Stress-strain curves of composite materials made of -co-BVBA2 nanofibers (6 parallel repeated experiments);

[0039] Figure 15The product containing 5.0 wt% PSMA obtained in Comparative Example 5 of this invention 21 -b-PSt 260 Stress-strain curves of nanofiber composite materials (6 parallel repeated experiments);

[0040] Figure 16 PSMA in Embodiment 9 of the present invention 21 -bP(St 260 TEM image of -co-BVBA2) nanofibers after high temperature and high shear treatment;

[0041] Figure 17 PSMA in Comparative Example 6 of this invention 21 -b-PSt 260 TEM image of nanofibers after high-temperature and high-shear treatment;

[0042] Figure 18 Example 10 of this invention contains 1.0 wt% PSMA 21 -bP(St 260 Photographs of composite materials of -co-BVBA2) nanofibers (i) thin film, (ii) after being cut up, and (iii) re-hot-pressed into new thin film;

[0043] Figure 19 Example 10 of this invention contains 1.0 wt% PSMA 21 -bP(St 260 Stress-strain curves of new films obtained by cutting and re-hot-pressing composite films of -co-BVBA2) nanofibers (5 parallel repeated experiments).

[0044] Figure 20 Example 11 of this invention contains 1.0 wt% PSMA 21 -bP(St 260 Microscopic photograph of the self-healing process of a composite material of -co-BVBA2) nanofibers after being cut with a blade;

[0045] Figure 21 Example 11 of this invention contains 1.0 wt% PSMA 21 -bP(St 260 Stress-strain curves of the composite material obtained by cutting with a blade and then self-healing (5 parallel repeated experiments).

[0046] Figure 22 NMR spectrum of crosslinking agent BVBA

[0047] Figure 23 NMR spectrum of oil-soluble macromolecular chain transfer agent PSMA21-PETTC Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0050] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0051] Example 1

[0052] 1.1 Synthesis of crosslinking agent BVBA

[0053] 1,6-Adipic acid (20.5 mmol, 3.0 g), potassium carbonate (41 mmol, 2.8 g), and dimethylformamide (100 mL) were added to a reaction flask. After stirring at room temperature for 30 min, the reaction mixture was transferred to an oil bath at 85 °C, and 4-chloromethylstyrene (64.5 mmol, 8.6 mL) was added. The mixture was stirred overnight. After the reaction was complete, the resulting mixture was cooled to room temperature and poured into a saturated sodium chloride solution. The mixture was extracted four times with ethyl acetate (4 × 200 mL). The organic phase was dried overnight with anhydrous sodium sulfate and concentrated by rotary evaporation. The crude product was further purified by column chromatography using ethyl acetate and petroleum ether as eluents (ethyl acetate: petroleum ether = 1:50, v / v). The final product was a white powder. Its structural formula is shown below, and its NMR spectrum is shown below. Figure 22 As shown.

[0054]

[0055] 1.2 Oil-soluble macromolecular chain transfer agent PSMA 21 -Synthesis of PETTC

[0056] The technical approach is as follows:

[0057]

[0058] SMA (20.3 g, 60 mmol), PETTC (665 mg, 2 mmol), and AIBN (65 mg, 0.4 mmol) were weighed and added to a dry polymerization tube. Toluene (21.0 g) was added to dissolve the reactants. After three cycles of freezing-vacuuming-thawing to remove oxygen, the polymerization tube was placed in a 70°C oil bath and stirred for 230 min. The reaction was cooled to room temperature and the polymerization tube was opened to terminate the polymerization. The polymerized solution was precipitated five times in ethanol to remove unreacted monomers. The precipitate was dried in a vacuum drying oven for 48 h, and the final product was a yellow powder.

[0059] 1.3 Oil-soluble cross-linked nanofibers PSMA 21 -bP(St 260 Synthesis of -co-BVBA2)

[0060] PSMA 21 PETTC (3.7 g, 0.5 mmol), TBPB (32 mg, 0.17 mmol), St (13.52 g, 130 mmol), and BVBA (0.38 g, 1 mmol) were dissolved in 99.9 g of mineral oil, and the solution was added to a dry polymerization flask. After three cycles of freezing-vacuuming-thawing to remove oxygen, the polymerization tube was placed in a 100°C oil bath and stirred for 24 h. The reaction was cooled to room temperature and the polymerization tube was opened to terminate the polymerization, yielding PSMA with a solid content of 15 wt%. 21 -bP(St 260 -co-BVBA2) nanofiber dispersion. The resulting PSMA 21 -bP(St 260 Transmission electron microscopy images of -co-BVBA2) nanofibers are shown below. Figure 1 As shown.

[0061] 1.4 Oil-soluble, uncrosslinked PSMA nanofibers 21 -b-PSt 260 Synthesis

[0062] Except for the absence of a crosslinking agent, the reaction conditions and experimental procedures were completely consistent with 1.3, resulting in the preparation of oil-soluble uncrosslinked nanofibers. The obtained PSMA... 21 -b-PSt 260 Transmission electron microscope images of nanofibers, as shown Figure 2 As shown.

[0063] Example 2

[0064] Synthesis of P(MMA-stat-nBA) substrate by soap-free emulsion polymerization: Methyl methacrylate (MMA) (200 g, 2.0 mol), butyl acrylate (nBA) (200 g, 1.56 mol), and potassium persulfate (KPS) (8.0 g, 30 mmol) were added to a dry polymerization flask, followed by the addition of deionized water (4000 g). After purging with nitrogen for 0.5 h to remove oxygen, the polymerization flask was placed in a 70°C oil bath and stirred for 7 h. The reaction was cooled to room temperature, and the polymerization was terminated by opening the flask. The resulting latex was allowed to stand for 2 h, the supernatant was removed, and the product was dried to obtain the polymer substrate P(MAA-stat-nBA). DOSY NMR spectroscopy showed that the product was mainly a copolymer of MMA and nBA. Figure 3 GPC displays the M of the obtained P(MAA-stat-nBA). w =111000( Figure 4 ).

[0065] Example 3

[0066] The P(MAA-stat-nBA) obtained in Example 2 was hot-pressed using a hot press. The temperature was set to 130°C, the lower pressure limit was set to 0.7 MPa, the upper pressure limit was set to 1.2 MPa, and the time was set to 3 min. After the sample cooled to room temperature, the mechanical properties of the resulting material were tested under the following conditions: tensile sensor model BAB=10MT, maximum loading force was 10 kg, preload stress was 0.01 N, and test speed was 10 mm / min. Figure 5 As shown in Table 1, the tensile strength of the obtained P(MAA-stat-nBA) substrate material is 4.2 ± 0.4 MPa, the elongation at break is 467% ± 34%, and the toughness is 14.4 ± 1.2 MJ / m. 3 .

[0067] Table 1. Average values ​​of tensile strength, elongation, and toughness of P(MMA-stat-nBA) substrate material (5 parallel replicate experiments)

[0068] sample strength Elongation toughness P(MMA-stat-nBA) 4.2±0.4MPa 467％±34％ <![CDATA[14.4±1.2MJ / m 3 ]]>

[0069] Example 4

[0070] Weigh the PSMA synthesized in Example 1.3 21 -bP(St 260-co-BVBA2) nanofibers (0.03g) and P(MAA-stat-nBA) synthesized in Example 2 (33.75g) were added to a mixer. The mixer temperature was set to 130℃, the speed was set to 30r / min, and the mixture was mechanically blended for 10min to obtain a polymer-nanofiber composite material with a nanofiber content of 0.1wt%. The obtained composite material was hot-pressed using a hot press, with the temperature set to 130℃, the lower pressure limit set to 0.7MPa, the upper pressure limit set to 1.2MPa, and the time set to 3min. After the sample cooled to room temperature, the mechanical properties of the obtained composite material were tested under the following conditions: tensile sensor model BAB=10MT, maximum loading force 10kg, preload stress 0.01N, and test speed 10mm / min. Figure 6 As shown in Table 2, containing 0.1 wt% PSMA 21 -bP(St 260 The composite material of -co-BVBA2) nanofibers has a tensile strength of 5.6 ± 0.3 MPa, an elongation at break of 602% ± 64%, and a toughness of 23.3 ± 4.7 MJ / m. 3 .

[0071] Table 2. PSMA with different contents 21 -bP(St 260 The average tensile strength, elongation, and toughness of the composite material modified with -co-BVBA2 nanofibers (6 parallel replicates for each sample).

[0072]

[0073]

[0074] Comparative Example 1

[0075] Weigh the PSMA synthesized in Example 1.4 21 -b-PSt 260 Nanofibers (0.03 g) and P(MAA-stat-nBA) (33.75 g) synthesized in Example 2 were added to a Banbury mixer. The mixer temperature was set to 130°C, the speed to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The resulting composite material was hot-pressed using a hot press at 130°C, with a lower pressure limit of 0.7 MPa, an upper pressure limit of 1.2 MPa, and a time of 3 min. After the sample cooled to room temperature, the mechanical properties of the resulting composite material were tested under the following conditions: a BAB=10MT tensile sensor, a maximum loading force of 10 kg, a preload stress of 0.01 N, and a test speed of 10 mm / min. Figure 7As shown in Table 3, containing 0.1 wt% PSMA 21 -b-PSt 260 The nanofiber composite material exhibits a tensile strength of 5.2 ± 0.3 MPa, an elongation at break of 609% ± 88%, and a toughness of 21.2 ± 4.1 MJ / m. 3 Table 3. PSMA with different contents 21 -b-PSt 260 The average tensile strength, elongation, and toughness of nanofiber modified composites (6 parallel replicates for each sample).

[0076]

[0077] Example 5

[0078] Weigh the PSMA synthesized in Example 1.3 21 -bP(St 260 -co-BVBA2) nanofibers (0.17g) and P(MAA-stat-nBA) synthesized in Example 2 (33.75g) were added to a mixer. The mixer temperature was set to 130℃, the speed was set to 30r / min, and the mixture was mechanically blended for 10min to obtain a composite material with a nanofiber content of 0.1wt%. The obtained composite material was hot-pressed using a hot press, with the temperature set to 130℃, the lower pressure limit set to 0.7MPa, the upper pressure limit set to 1.2MPa, and the time set to 3min. After the sample cooled to room temperature, the mechanical properties of the obtained composite material were tested under the following conditions: tensile sensor model BAB=10MT, maximum loading force 10kg, preload stress 0.01N, and test speed 10mm / min. Figure 8 As shown in Table 2, containing 0.5 wt% PSMA 21 -bP(St 260 The composite material of -co-BVBA2) nanofibers has a tensile strength of 8.0±0.5MPa, an elongation at break of 1141%±169%, and a toughness of 54.7±11.4MJ / m. 3 .

[0079] Comparative Example 2

[0080] Weigh the PSMA synthesized in Example 1.4 21 -b-PSt 260Nanofibers (0.17 g) and P(MAA-stat-nBA) (33.75 g) synthesized in Example 2 were added to a Banbury mixer. The mixer temperature was set to 130°C, the speed to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The resulting composite material was then hot-pressed using a hot press at 130°C, with a lower pressure limit of 0.7 MPa, an upper pressure limit of 1.2 MPa, and a time of 3 min. After the sample cooled to room temperature, the mechanical properties of the resulting composite material were tested under the following conditions: a BAB=10MT tensile sensor, a maximum loading force of 10 kg, a preload stress of 0.01 N, and a test speed of 10 mm / min. Figure 9 As shown in Table 3, containing 0.5 wt% PSMA 21 -b-PSt 260 The nanofiber composite material exhibits a tensile strength of 6.5 ± 0.3 MPa, an elongation at break of 778% ± 195%, and a toughness of 32.8 ± 8.5 MJ / m. 3 .

[0081] Example 6

[0082] Weigh the PSMA synthesized in Example 1.3 21 -bP(St 260 -co-BVBA2) nanofibers (0.34 g) and P(MAA-stat-nBA) synthesized in Example 2 (33.75 g) were added to a mixer. The mixer temperature was set to 130°C, the speed was set to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The obtained composite material was hot-pressed using a hot press, with the temperature set to 130°C, the lower pressure limit set to 0.7 MPa, the upper pressure limit set to 1.2 MPa, and the time set to 3 min. After the sample cooled to room temperature, the mechanical properties of the obtained composite material were tested under the following conditions: tensile sensor model BAB=10MT, maximum loading force 10 kg, preload stress 0.01 N, and test speed 10 mm / min. Figure 10 As shown in Table 2, containing 1.0 wt% PSMA 21 -bP(St 260 The composite material of -co-BVBA2) nanofibers has a tensile strength of 10.9 ± 1.2 MPa, an elongation at break of 1657% ± 450%, and a toughness of 104.2 ± 26.6 MJ / m. 3 .

[0083] Comparative Example 3

[0084] Weigh the PSMA synthesized in Example 1.4 21 -b-PSt260 Nanofibers (0.34 g) and P(MAA-stat-nBA) (33.75 g) synthesized in Example 2 were added to a Banbury mixer. The mixer temperature was set to 130°C, the speed to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The resulting composite material was hot-pressed using a hot press at 130°C, with a lower pressure limit of 0.7 MPa, an upper pressure limit of 1.2 MPa, and a time of 3 min. After the sample cooled to room temperature, the mechanical properties of the resulting composite material were tested under the following conditions: a BAB=10MT tensile sensor, a maximum loading force of 10 kg, a preload stress of 0.01 N, and a test speed of 10 mm / min. Figure 11 As shown in Table 3, containing 1.0 wt% PSMA 21 -b-PSt 260 The nanofiber composite material exhibits a tensile strength of 8.9 ± 0.6 MPa, an elongation at break of 895% ± 217%, and a toughness of 46.7 ± 11.2 MJ / m. 3 .

[0085] Example 7

[0086] Weigh the PSMA synthesized in Example 1.3 21 -bP(St 260 -co-BVBA2) nanofibers (1.01 g) and P(MAA-stat-nBA) synthesized in Example 2 (33.75 g) were added to a mixer. The mixer temperature was set to 130°C, the speed was set to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The obtained composite material was hot-pressed using a hot press, with the temperature set to 130°C, the lower pressure limit set to 0.7 MPa, the upper pressure limit set to 1.2 MPa, and the time set to 3 min. After the sample cooled to room temperature, the mechanical properties of the obtained composite material were tested under the following conditions: tensile sensor model BAB=10MT, maximum loading force 10 kg, preload stress 0.01 N, and test speed 10 mm / min. Figure 12 As shown in Table 2, containing 3.0 wt% PSMA 21 -bP(St 260 The composite material of -co-BVBA2) nanofibers has a tensile strength of 10.0 ± 1.0 MPa, an elongation at break of 1156% ± 228%, and a toughness of 68.0 ± 11.9 MJ / m. 3 .

[0087] Comparative Example 4

[0088] Weigh the PSMA synthesized in Example 1.421 -b-PSt 260 Nanofibers (1.01 g) and P(MAA-stat-nBA) (33.75 g) synthesized in Example 2 were added to a Banbury mixer. The mixer temperature was set to 130°C, the speed to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The resulting composite material was hot-pressed using a hot press at 130°C, with a lower pressure limit of 0.7 MPa, an upper pressure limit of 1.2 MPa, and a time of 3 min. After the sample cooled to room temperature, the mechanical properties of the resulting composite material were tested under the following conditions: a BAB=10MT tensile sensor, a maximum loading force of 10 kg, a preload stress of 0.01 N, and a test speed of 10 mm / min. Figure 13 As shown in Table 3, containing 3.0 wt% PSMA 21 -b-PSt 260 The nanofiber composite material exhibits a tensile strength of 7.2 ± 0.8 MPa, an elongation at break of 913% ± 201%, and a toughness of 42.5 ± 14.5 MJ / m. 3 .

[0089] Example 8

[0090] Weigh the PSMA synthesized in Example 1.3 21 -bP(St 260 -co-BVBA2) nanofibers (1.69 g) and P(MAA-stat-nBA) synthesized in Example 2 (33.75 g) were added to a mixer. The mixer temperature was set to 130°C, the speed was set to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The obtained composite material was hot-pressed using a hot press, with the temperature set to 130°C, the lower pressure limit set to 0.7 MPa, the upper pressure limit set to 1.2 MPa, and the time set to 3 min. After the sample cooled to room temperature, the mechanical properties of the obtained composite material were tested under the following conditions: tensile sensor model BAB=10MT, maximum loading force 10 kg, preload stress 0.01 N, and test speed 10 mm / min. Figure 14 As shown in Table 2, containing 5.0 wt% PSMA 21 -bP(St 260 The composite material of -co-BVBA2) nanofibers has a tensile strength of 6.6 ± 0.4 MPa, an elongation at break of 658% ± 23%, and a toughness of 29.1 ± 1.2 MJ / m. 3 .

[0091] Comparative Example 5

[0092] Weigh the PSMA synthesized in Example 1.4 21 -b-PSt 260 Nanofibers (1.69 g) and P(MAA-stat-nBA) (33.75 g) synthesized in Example 2 were added to a Banbury mixer. The mixer temperature was set to 130°C, the speed to 30 r / min, and the mixture was mechanically blended for 10 min to obtain a composite material with a nanofiber content of 0.1 wt%. The resulting composite material was hot-pressed using a hot press at 130°C, with a lower pressure limit of 0.7 MPa, an upper pressure limit of 1.2 MPa, and a time of 3 min. After the sample cooled to room temperature, the mechanical properties of the resulting composite material were tested under the following conditions: a BAB=10MT tensile sensor, a maximum loading force of 10 kg, a preload stress of 0.01 N, and a test speed of 10 mm / min. Figure 15 As shown in Table 3, containing 5.0 wt% PSMA 21 -b-PSt 260 The nanofiber composite material exhibits a tensile strength of 5.5 ± 0.4 MPa, an elongation at break of 751% ± 211%, and a toughness of 29.1 ± 7.4 MJ / m. 3 .

[0093] Example 9

[0094] Polymer nanofiber processing stability test: (1) PSMA 21 -bP(St 260 -co-BVBA2) nanofibers were heated to 130℃ and stirred at 30 rpm for 10 minutes. The morphology and structure of the treated nanofibers were characterized using transmission electron microscopy (TEM). The results showed that the structure of the nanofibers remained almost unchanged. Figure 16 This indicates that the core-crosslinked nanofibers have excellent structural stability and can maintain their fibrous structure during high-temperature and high-shear processing, thus exhibiting superior reinforcing effects.

[0095] Comparative Example 6

[0096] Polymer nanofiber processing stability test: (1) PSMA 21 -b-PSt 260 Nanofibers were heated to 130℃ and stirred at 30 rpm for 10 minutes. The morphology and structure of the treated nanofibers were characterized using transmission electron microscopy (TEM). The results showed that many nanofibers degraded into spherical structures. Figure 17This indicates that the structure of the uncrosslinked nanofibers is not stable enough and degrades into spherical nanomaterials during high-temperature and high-shear processing, thus weakening the reinforcing effect of the nanofiller (Note: the reinforcing effect of spherical nanofillers is not as good as that of fibrous nanofillers).

[0097] Example 10

[0098] Repeat processing properties of the obtained polymer-nanofiber composite: The composite material containing 1.0 wt% PSMA... 21 -bP(St 260 The composite material of -co-BVBA2) nanofibers was shredded and then re-hot-pressed. The pressing machine temperature was set to 130℃, the lower pressure limit was set to 0.7MPa, the upper pressure limit was set to 1.2MPa, and the time was set to 3min, resulting in a secondary-processed cross-linked micelle-reinforced membrane. The reprocessed membrane was almost indistinguishable from the original membrane material, both exhibiting good transparency. Figure 18 The strength, elongation, and toughness of the membrane after repeated processing were 11.5 ± 0.5 MPa, 1500% ± 152%, and 92.3 ± 8.0 MJ / m, respectively. 3 This is almost identical to the original membrane material. Figure 19 (See Table 4) to show that the nanofiber-reinforced composite material has good reprocessability.

[0099] Table 4. Containing 1.0 wt% PSMA 21 -bP(St 260 The average tensile strength, elongation, and toughness of the composite material modified with -co-BVBA2 nanofibers after being sheared and re-hot-pressed (5 parallel replicate experiments).

[0100] sample strength Elongation toughness Samples after repeated processing 11.5±0.5MPa 1500％±152％ <![CDATA[92.3±8.0MJ / m 3 ]]>

[0101] Example 11

[0102] The self-healing properties of the obtained polymer-nanofiber composite: The composite material contains 1.0 wt% PSMA. 21 -bP(St 260 When a slit is made in the composite material of -co-BVBA2) nanofibers with a blade and the membrane is placed in an environment of 50°C for 14 hours, the slit completely disappears. Figure 20 The strength, elongation, and toughness of the material after healing were 9.9±0.5 MPa, 1511%±167%, and 78.4±7.0 MJ / m, respectively. 3 ( Figure 21 As shown in Table 5, this material is almost identical to the original material, indicating that the nanofiber-reinforced composite material has good self-healing properties.

[0103] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

[0104] Table 5. Containing 1.0 wt% PSMA 21 -bP(St 260 The tensile strength, elongation, and toughness of the composite material modified with -co-BVBA2 nanofibers after being cut and undergoing self-healing over a period of time are the average values ​​(5 parallel replicate experiments).

[0105] sample strength Elongation toughness Self-healing sample 9.9±0.5MPa 1511％±167％ <![CDATA[78.4±7.0MJ / m 3 ]]>

Claims

1. A method for preparing an oil-soluble, core-crosslinked fibrous nanofiller, characterized in that, The following steps are involved: 1) Dissolve monomer M1, diacid A1, and acid-binding agent in a solvent and initiate an esterification reaction to obtain crosslinking agent C1, wherein M1 is a monomer containing esterification reaction sites and double bonds; 2) Dissolve monomer M2, chain transfer agent CTA, and initiator in a solvent and initiate polymerization to obtain oil-soluble macromolecular chain transfer agent P2-CTA, where P2 is a polymer and CTA is a chain transfer agent containing polymeric active ends; 3) Dissolve the oil-soluble macromolecular chain transfer agent P2-CTA, monomer M3, crosslinking agent C1, and initiator in a solvent and initiate polymerization to obtain an oil-soluble and core-crosslinked fibrous nanofiller, wherein the surface chain segment of the fibrous nanofiller is the oil-soluble polymer P2, and the core chain segment is the crosslinked polymer P3.

2. The preparation method according to claim 1, characterized in that, In step 1), monomer M1 is 4-chloromethylstyrene, diacid A1 is 1,6-adipic acid, and the acid-binding agent is selected from any one of pyridine, triethylamine, sodium carbonate, potassium carbonate, and sodium acetate; more preferably, potassium carbonate, and the solvent is dimethylformamide, tetrahydrofuran, or dimethyl sulfoxide.

3. The preparation method according to claim 1, characterized in that, In step 2), the monomer M2 is octadecyl methacrylate, the oil-soluble polymer is polyoctadecyl methacrylate, the chain transfer agent CTA is PETTC, and the solvent is either toluene or mineral oil.

4. The preparation method according to claim 1, characterized in that, In step 3), the monomer M3 is styrene, the molar ratio of the oil-soluble macromolecular chain transfer agent P2-CTA to the crosslinking agent C1 is 1:(2-10), preferably 1:2; and the solvent is toluene.

5. The preparation method according to claim 1, characterized in that, The initiator mentioned in steps 2) and 3) is selected from any one of azo compounds, peroxides, disulfides and compounds containing NO bonds; preferably, it is one of azobisisobutyronitrile (AIBN) and tert-butyl peroxide (TBPB).

6. An oil-soluble, core-crosslinked fibrous nanofiller prepared according to any one of claims 1-5.

7. The application of the oil-soluble and core-crosslinked fibrous nanofiller of claim 6 in the preparation of polymer-nanofiber composite materials.

8. A polymer-nanofiber composite material, characterized in that, The polymer-nanofibers composite material is prepared by means of the oil-soluble and core-crosslinked fibrous nanofiller as described in claim 6; preferably, the oil-soluble and core-crosslinked fibrous nanofiller as described in claim 6 is incorporated into the polymer substrate in a certain proportion, and then mechanically stirred and mixed evenly in an internal mixer to prepare the polymer-nanofibers composite material; wherein, the temperature of the internal mixer is the melting or viscous flow temperature of the polymer substrate, preferably 50-300℃.

9. The polymer-nanofiber composite material according to claim 8, characterized in that, The polymer base is prepared by soap-free emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (nBA) mixed in water.

10. The polymer-nanofiber composite material according to claim 8, characterized in that, The oil-soluble and core-crosslinked fibrous nanofiller is incorporated in an amount of (0.1-5)% of the total weight of the polymer substrate, preferably 1%.

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